Handbook of Research on Mobility and Computing: Evolving Technologies and Ubiquitous Impacts Maria Manuela Cruz-Cunha Polytechnic Institute of Cávado e Ave, Portugal Fernando Moreira Universidade Portucalense, Portugal
Volume I
INFORMATION SCIENCE REFERENCE Hershey • New York
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[email protected] Web site: http://www.igi-global.com Copyright © 2011 by IGI Global. All rights reserved. No part of this publication may be reproduced, stored or distributed in any form or by any means, electronic or mechanical, including photocopying, without written permission from the publisher. Product or company names used in this set are for identification purposes only. Inclusion of the names of the products or companies does not indicate a claim of ownership by IGI Global of the trademark or registered trademark. Library of Congress Cataloging-in-Publication Data Handbook of research on mobility and computing : evolving technologies and ubiquitous impacts / Maria Manuela Cruz-Cunha and Fernando Moreira, editors. p. cm. Includes bibliographical references and index. ISBN 978-1-60960-042-6 (hbk.) -- ISBN 978-1-60960-043-3 (ebook) 1. Mobile computing. 2. Wireless communication systems. I. Cruz-Cunha, Maria Manuela, 1964- II. Moreira, Fernando, 1969 Aug. 16QA76.59.H35 2011 004.165--dc22 2010036723 British Cataloguing in Publication Data A Cataloguing in Publication record for this book is available from the British Library. All work contributed to this book is new, previously-unpublished material. The views expressed in this book are those of the authors, but not necessarily of the publisher.
Editorial Advisory Board Goran D. Putnik, University of Minho, Portugal João Varajão, University of Trás-os-Montes e Alto Douro, Portugal Joaquim Arnaldo Martins, Universidade de Aveiro, Portugal Nuno Lopes, Polytechnic Institute of Cávado e Ave, Portugal Patrícia Gonçalves, Polytechnic Institute of Cávado e Ave, Portugal Paulo Ferreira, INESC Porto, Portugal Vítor Carvalho, Polytechnic Institute of Cávado e Ave, Portugal
List of Reviewers Abdellah Touhafi, Erasmushogheschool, Belgium Abid Yahya, Universiti Sains Malaysia, Malaysia Abilio Azenha, ISR – Porto, Portugal Adriano Carvalho, ISR-Porto, Portugal Agostino Poggi, University of Parma, Italy An Braken, Erasmushogeschool, Belgium Ana Isabel González-Tablas, Univ. Carlos III of Madrid, Spain Ana María Fermoso García, Universidad Pontificia de Salamanca, Spain Andrea Zanda, Universidad Politecnica Madrid, Spain Andreas Ahrens, Hochschule Wismar - University of Technology, Germany Anselmo Cardoso de Paiva, University of the Maranhão, Brazil Antonio Foncubierta Rodriguez, University of Seville, Spain Aparecido Fabiano de Carvalho, University of Limerick, Republic of Ireland Arturo Molina, Tecnologico de Monterrey, Mexico Aysegul Cayci, Sabanci University, Turkey Bahram Lotfisadigh, Middle East Technical University, USA Bart De Decker, K.U. Leuven, Belgium Bruno Kimura, University of São Paulo, Brazil C. Brad Crisp, Abilene Christian University, USA Carlo Bertolli, University of Pisa, Italy Carlos Ferras, University of Santiago, Spain
Carlos Quental, ESTV / IPV, Portugal Carmen Ruthenbeck, University of Bremen, Germany Castor Sánchez Chao, University of Vigo, Spain Célia Menezes, Escola Sec. Inf. D. Henrique, Portugal César Benavente-Peces, EUIT Telecomunicacion - Universidad Politécnica de Madrid, Spain Chad Lin, Curtin University of Technology, Australia Chongming Zhang, Shanghai Normal University, China Cláudio de Souza Baptista, University of Campina Grande, Brazil Crescenzio Gallo, University of Foggia, Italy Cristiano Costa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Cristina Rodriguez-Sanchez, Universidad Rey Juan Carlos, Spain Daniel Câmara, EURECOM, France Daniele Buono, University of Pisa, Italy David Santos, Universidad San Pablo-CEU, Spain Dennis Viehland, Massey University, New Zeland Diana Bri, Polytechnic University of Valencia, Spain Edson Moreira, University of Sao Paulo, Brazil Elena Nazzi, IT-University of Copenhagen, Denmark Emanuel Angelescu, RWTH, Germany Emanuel Correia, University of Trás-os-Montes e Alto Douro, Portugal Emanuel Soares Peres Correia, Universidade de Trás-os-Montes e Alto Douro, Portugal Encarnación Beato Gutierrez, Universidad Pontificia de Salamanca, Spain Ernestina Menasalvas, Universitad Politecnica Madrid, Spain Ernesto Morales Kluge, BIBA, Gremany Fernando Lopez-Colino, UAM, Spain Fernando Moreira, Universidade Portucalense Infante D. Henrique, Portugal Florian Harjes, BIBA, Germany Francisco Rodríguez-Díaz, University of Granada, Spain Francisco Amaral, University of the Azores, Portugal Gabriele Mencagli, University of Pisa, Italy Gianluca Cornetta, Universidad San Pablo-CEU, Spain Gonzalo Aranda-Corral, University of Sevilla, Spain Greg Wilson, Virginia Tech, USA Gustavo Lermen, Universidade do Vale do Rio dos Sinos (Unisinos), Brasil Hakki Unver, TOBB-ETU, USA Hamilton Turner, Vanderbilt University, USA Hassan Karimi, University of Pittsburgh, USA Heather Katz Hugo Coll, Polytechnic University of Valencia, Spain Hugo Feitosa de Figueirêdo, University of Campina Grande, Brazil Ismael Bouassida Rodriguez, LAAS-CNRS, France Isidro Vila Verde, Faculdade de Engenharia da Universidade do Porto, Portugal J. Stephanie Collins, Southern NH University, USA Jaime Lloret, Polytechnic University of Vale, Spain
Jairo Gutierrez, University of Auckland, New Zealand Javier Pereira Loureiro, University of A Coruna, Spain Jérôme Lacouture, LAAS-CNRS, France Jiaxiang Gan, University of Auckland, New Zealand João Barreto, Inesc-ID/UTL, Portugal João Bartolo Gomes, Universitad Politecnica Madrid, Spain João Carmo, University of Minho, Portugal João Eduardo Quintela Alves de Sousa Varajão, Universidade de Trás-os-Montes e Alto Douro, Portugal João Rosa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Joaquim Arnaldo Martins, Universidade de Aveiro, Portugal Joaquín Borrego-Díaz, University of Sevilla, Spain Joaquim Sousa Pinto, Universidade de Aveiro, Portugal Jorge Ferreira, E-Geo FCSH, Portugal Jorge Luís Barbosa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil José Colas, UAM, Spain José Delgado, Instituto Superior Técnico, Portugal José Eustáquio Rangel de Queiroz, University of Campina Grande, Brazil José María De Fuentes, University Carlos III of Madrid, Spain José Maria Monguet-Fierro, UPC, Spain Juan Álvaro Muñoz Naranjo, Universidad de Almería, Spain Juan Antonio López Ramos, Universidad de Almería, Spain Juan Carlos González Moreno, University of Vigo, Spain Juan Hernandez-Tamames, Universidad Rey Juan Carlos, Spain Júlio cesar Melo, UFRN, Brazil Justo Peralta López, Universidad de Almería, Spain Kathryn Hayes, UWS, Australia Kelvin Bwalya, University of Botswana, Botswana Koong Lin, National University of Tainan, Taiwan Krassie Petrova, Auckland University of Technology, New Zeland Kris Steenhaut, Vrije Universiteit Brussel, Belgium Laerte Franco, Unisinos, Brazil Laura Nieto Riveiro, University of A Coruna, Spain Nuno Lopes, Polytechnic Institute of Cávado and Ave, Portugal Luca Vassena, University of Udine, Italy Luciana Arantes, LIP6/INRIA, France Luís Villaseñor, CICESE Research Centre, Mexico Luís Gouveia, Univ.Fernando Pessoa, Portugal Luís Peneda, ISR-Porto, Portugal Luís Serrano, Polithecnic Institute Leiria, Portugal Luís Veiga, INESC ID / Technical University of Lisbon, Portugal Luiz Marcos Gonçalves, UFRN, Brazil Mahsa Ghafourian, University of Pittsburgh, USA Mamun Abu-Tair, ECIT, UK Marco Vanneschi, University of Pisa, Italy
Marcus Bjelkemyr, The Royal Institute of Technology, Sweden Maria Borges Tiago, University of the Azores, Portugal Maria João Ferreira, Universidade Portucalense, Portugal Maria Manuela Cruz-Cunha, Polytechnic Institute of Cávado e Ave, Portugal Martin Stigmar, Växjö University, Sweden Mauro Onori, The Royal Institute of Technology, Sweden Maximino Esteves Correia Bessa, Universidade de Trás-os-Montes e Alto Douro, Portugal Michael Decker, University of Karlsruhe, Germany Michael Williams, Pepperdine University, USA Michelangelo De Bonis, University of Foggia, Italy Michele Perilli, University of Foggia, Italy Michele Tomaiuolo, University of Parmaz, Italy Miguel Angel Sánchez Vidales, Universidad Pontificia de Salamanca, Spain Miguel Garcia, Polytechnic University of Valencia, Spain Miguel Monteiro, Universidade do Porto, Portugal Milos Stojmenovic, University of Ottawa, Canada Montserrat Mateos Sánchez, Universidad Pontificia de Sala, Spain Nabeel Ahmad, IBM, USA Naoe Tatara, Norwegian Centre for Integrated Care and Telemedicine, Norway Natalia Padilla Zea, University of Granada, Spain Nicholas Pagden, Växjö University, Sweden Nikolaos Frangiadaki, University of Maryland, USA Nuno André Osório Liberato, Universidade de Trás-os-Montes e Alto Douro, Portugal Nuno Flores, Universidade do Porto, Portugal Nuno Lau, Universidade de Aveiro, Portugal Nuno Lopes, Polytechnic Institute of Cávado e Ave, Portugal Nuno Veiga, IPLeiria, Portugal Patrícia Gonçalves, Polytechnic Institute of Cávado and Ave, Portugal Paula Vicente, ISCTE-IUL, Portugal Paulo Ferreira, INESC ID / IST, Portugal Pedro Campos, University of Madeira, Portugal Pethuru Raj Chelliah, Wipro Technologies, USA Pierre Kirisci, BIBA, Germany Pierre Sens, LIP6/INRIA, France Qixiang Pang, General Dynamics Canada, Canada Raúl Aquino, University of Colima, Mexico Riikka Vuokko, Åbo Akademi University, Finland Roberto Berjón Gallinas, Universidad Pontificia de Salamanca, Spain Roberto Yokoyama, University of Sao Paulo, Brazil Rubén Romero González, University of Vigo, Portugal Rui Rijo, IPLeiria, Portugal Rummenigge Dantas, UFRN, Brasil Sandra Sendra, Polytechnic University of Valencia, Spain Santiago Eibe, Universitad Politecnica Madrid, Spain
Sílvio Bernardes, IPLeiria, Portugal Sohail Anwar, Penn State University, USA Thierry Desprats, IRIT, France Tom Chan, Southern NH University, USA Victor Gonzalez, University of Manchester, UK Víctor Rangel, National Autonomous University of Mexico, Mexico Vincenzo Pallotta, University of Geneva, Switzerland Violeta Chirino-Barceló, Tecnológico de Monterrey, Mexico Xinyu Lu, General Dynamics, Canada Yelena Zascerinska, University of Latvia, Republic of Latvia
List of Contributors
Abreu, Jorge / University of Aveiro, Portugal.................................................................................... 414 Ahmad, Nabeel / IBM Center for Advanced Learning, USA.............................................................. 871 Ahmad, R. Badlishah / Universiti Malaysia Perlis, Malaysia.......................................................... 157 Ahrens, Andreas / University of Technology, Business and Design, Germany.......................... 100, 760 Almeida, Margarida / University of Aveiro, Portugal....................................................................... 414 Almeida, Pedro / University of Aveiro, Portugal................................................................................ 414 Amaral, Francisco / University of the Azores, Portugal.................................................................... 327 Angelescu, Emanuel / Bremer Institut für Produktion und Logistik GmbH, Germany.................... 1226 Antunes, Maria / University of Aveiro, Portugal............................................................................... 414 Anwar, Sohail / Penn State University, USA...................................................................................... 237 Aquino, Raúl / University of Colima, México.................................................................................... 595 Aranda-Corral, Gonzalo / University of Sevilla, Spain.................................................................... 667 Arantes, Luciana / University Paris 6, France................................................................................ 1039 Arcangeli, Jean-Paul / Paul Sabatier University, France................................................................ 1056 Årsand, Eirik / Norwegian Centre for Integrated Care and Telemedicine, Norway.......................... 136 Astray, Loxo Lueiro / University of Vigo, Spain................................................................................ 445 Augustin, Iara / Federal University of Santa Maria, Brazil ........................................................... 1077 Ayu, Media / International Islamic University Malaysia, Malaysia.......................................... 539, 558 Azevedo, Renato / Federal University of Santa Maria, Brazil........................................................ 1077 Barbosa, Jorge / Universidade do Vale do Rio dos Sinos (Unisinos), Brazil..................................... 634 Barreto, João / INESC-ID/Technical University Lisbon, Portugal.......................................................1132 Bártolo Gomes, João / Universitad Politecnica, Spain...................................................................... 576 Bassus, Olaf / University of Technology, Business and Design, Germany......................................... 760 Benavente-Peces, César / Universidad Politécnica de Madrid, Spain.............................................. 100 Bernardes, Silvio / IPLeiria, Portugal............................................................................................... 487 Bertolli, Carlo / University of Pisa, Italy............................................................................................ 617 Bjelkemyr, Marcus / The Royal Institute of Technology, Sweden...................................................... 821 Bonnet, Christian / EURECOM Sophia Antipolis, France........................................................ 267, 356 Borrego-Díaz, Joaquín / University of Sevilla, Spain........................................................................ 667 Borromeo, Susana / Universidad Rey Juan Carlos, Spain................................................................ 472 Braeken, An / Erasmushogeschool Brussel, Belgium......................................................................... 930 Bri, Diana / Polytechnic University of Valencia, Spain.................................................................... 1155 Buono, Daniele / University of Pisa, Italy.......................................................................................... 617
Burlamaqui, Aquiles / Universidade Federal do Rio Grande do Norte, Brasil................................ 397 Busch, Cristina Diaz / University of A Coruna, Spain..................................................................... 1169 Cabrera, Marcelino / University of Granada, Spain......................................................................... 368 Câmara, Daniel / EURECOM Sophia Antipolis, France........................................................... 267, 356 Campos, Pedro / University of Madeira, Portugal............................................................................ 793 Canovas, Alejandro / Polytechnic University of Valencia, Spain...................................................... 426 Carmo, João Paulo / University of Minho, Portugal....................................................................... 1021 Cayci, Aysegul / Sabanci University, Turkey...................................................................................... 576 Cerquides Bueno, José Ramón / University of Seville, Spain......................................................... 1199 Chapman, Ross / Deakin University Melbourne, Australia................................................................. 65 Chassot, Christophe / Université de Toulouse, France................................................................... 1056 Chawla, Sheenu / SUSH Global Solutions, New Zealand.................................................................. 314 Chirino-Barceló, Violeta / Tecnologico de Monterrey Mexico, Mexico............................................ 774 Ciolfi, Luigina / University of Limerick, Republic of Ireland............................................................. 381 Colás, Jose / Universidad Autónoma de Madrid, Spain....................................................................... 83 Coll, Hugo / Polytechnic University of Valencia, Spain................................................................... 1155 Cornetta, Gianluca / Universidad San Pablo-CEU, Spain...................................................................... Cornetta, Gianluca / Universidad San Pablo-CEU, Spain........................................................ 930, 994 Correia, José Higino / University of Minho, Portugal..................................................................... 1021 Costa, Cristiano / Universidade do Vale do Rio dos Sinos (Unisinos), Brazil................................... 634 Costa, José / University Coimbra, Portugal....................................................................................... 703 Crisp, C. Brad / Abilene Christian University, USA........................................................................ 1213 Cunha, Maria / Pontificia Universidade Católica do PR, Brazil..................................................... 1091 da Silva, Tiago Eduardo / University of Campina Grande, Brazil.................................................. 1104 Dantas, Rummenigge / Universidade Federal do Rio Grande do Norte, Brasil............................... 397 de Bonis, Michelangelo / University of Foggia, Italy.......................................................................... 31 de Carvalho, Aparecido Fabiano Pinatti / University of Limerick, Republic of Ireland................. 381 de Decker, Bart / Katholieke Universiteit Leuven, Belgium............................................................. 1246 de Figueirêdo, Hugo Feitosa / University of Campina Grande, Brazil........................................... 1104 de Fuentes, José María / Carlos III University of Madrid, Spain..................................................... 894 de Paiva, Anselmo Cardoso / University of Maranhão, Brazil....................................................... 1104 de Queiroz, José Eustáquio Rangel / University of Campina Grande, Brazil................................ 1104 de Sousa Varajão, João Eduardo Quintela Alves / UTAD, Portugal.............................................. 881 de Souza Baptista, Cláudio / University of Campina Grande, Brazil............................................. 1104 Decker, Michael / Karlsruhe Institute of Technology (KIT), Germany.............................................. 912 Delgado, Jose / Instituto Superior Técnico, Portugal......................................................................... 853 Demetriou, Antonis / University of Manchester, UK....................................................................... 1262 Desprats, Thierry / Paul Sabatier University, France..................................................................... 1056 Dias, Ricardo / Universidade Federal do Rio Grande do Norte, Brasil............................................ 397 Dillenburg, Fabiane / Universidade Federal do Rio Grande do Sul, Brazil..................................... 634 Dougherty, Brian / Vanderbilt University, USA................................................................................. 502 Drira, Khalil / Université de Toulouse, France................................................................................ 1056 Edo, Miguel / Polytechnic University of Valencia, Spain................................................................... 426 Edwards, Artur / University of Colima, México................................................................................ 595
Eibe, Santiago / Universitad Politecnica, Spain................................................................................. 576 Esteves Correia Bessa, Maximino / UTAD, Portugal....................................................................... 881 Fermoso García, Ana María / Universidad Pontificia de Salamanca, Spain................................... 216 Ferrás, Carlos / University of Santiago Compostela, Spain............................................................. 1182 Ferreira, Paulo / INESC ID / Technical University of Lisbon, Portugal...................................719, 1132 Filali, Fethi / EURECOM, Qatar................................................................................................. 267,356 Foncubierta Rodriguez, Antonio / University of Seville, Spain...................................................... 1199 Frangiadakis, Nikolaos / University of Maryland, USA.................................................................... 356 Freitas, Leandro / Federal University of Santa Maria, Brazil......................................................... 1077 Gallinas, Roberto Berjón / Universidad Pontificia de Salamanca, Spain........................................ 216 Gallo, Crescenzio / University of Foggia, Italy.................................................................................... 31 Gan, Jiaxiang / University of Auckland, New Zealand....................................................................... 837 Garcia, Miguel / Polytechnic University of Valencia, Spain...................................................... 426, 595 Garcia, Osvaldo / Pontificia Universidade Católica do PR, Brazil................................................. 1091 García, Yolanda / University of Santiago Compostela, Spain.......................................................... 1182 Garijo, Francisco / Université de Toulouse, France........................................................................ 1056 Garzão, Alex / Universidade do Vale do Rio dos Sinos (Unisinos), Brazil........................................ 634 Gassen, Jonas / Federal University of Santa Maria, Brazil............................................................. 1077 Ghafourian, Mahsa / University of Pittsburgh, USA................................................................. 203, 298 Ghani, Farid / Universiti Malaysia Perlis, Malaysia......................................................................... 157 Gonçalves, Luiz Marcos / Universidade Federal do Rio Grande do Norte, Brasil.......................... 397 González Moreno, Juan Carlos / University of Vigo, Spain............................................................. 445 González, Betania Groba / University of A Coruna, Spain............................................................. 1169 Gonzalez, Victor / University of Manchester, UK............................................................................ 1262 González-Tablas, Ana Isabel / Carlos III University of Madrid, Spain............................................ 894 Gouveia, Luis / University Fernando Pessoa, Portugal..................................................................... 974 Grahn, Kaj / Arcada University of Applied Sciences, Finland.......................................................... 952 Gray, Breda / University of Limerick, Republic of Ireland................................................................ 381 Greve, Fabíola / Federal University of Bahia, Brazil...................................................................... 1039 Gutierrez, Encarnación Beato / Universidad Pontificia de Salamanca, Spain................................ 216 Gutiérrez, Jairo A. / Universidad Tecnológica de Bolívar, Colombia............................................... 837 Harjes, Florian / Bremer Institut für Produktion und Logistik, Germany.......................................... 738 Hartvigsen, Gunnar / University of Tromsø, Norway........................................................................ 136 Hayes, Kathryn J. / University of Western Sydney, Australia.............................................................. 65 Hernandez-Tamames, Juan / Universidad Rey Juan Carlos, Spain................................................. 472 Huang, Yu-An / National Chi Nan University, Taiwan...................................................................... 175 Iapichino, Giuliana / EURECOM, France......................................................................................... 267 Jalleh, Geoffrey / Curtin University of Technology, Australia........................................................... 175 Joseph, Bwalya Kelvin / University of Johannesburg, South Africa................................................... 48 Karimi, Hassan / University of Pittsburgh, USA........................................................................ 203, 298 Karlsson, Jonny / Arcada University of Applied Sciences, Finland.................................................. 952 Kimura, Bruno / University of São Paulo, Brazil.............................................................................. 522 Kirisci, Pierre / Bremer Institut für Produktion und Logistik GmbH, Germany.............................. 1226 Koong Lin, Hao-Chiang / National University of Tainan, Taiwan.................................................... 175
Kurtz, Guilherme / Federal University of Santa Maria, Brazil...................................................... 1077 Lacouture, Jérôme / Université de Toulouse, France...................................................................... 1056 Lermen, Gustavo / Universidade do Vale do Rio dos Sinos (Unisinos), Brazil................................. 634 Librelotto, Giovani / Federal University of Santa Maria, Brazil.................................................... 1077 Lin, Chad / Curtin University of Technology, Australia..................................................................... 175 Lloret, Jaime / Polytechnic University of Valencia, Spain....................................................... 426, 1155 López Ramos, Juan Antonio / Universidad de Almería, Spain......................................................... 188 López, Justo Peralta / Universidad de Almería, Spain...................................................................... 188 López-Colino, Fernando / Universidad Autónoma de Madrid, Spain................................................. 83 Maffei, Antonio / The Royal Institute of Technology, Sweden............................................................ 821 Mantoro, Teddy / International Islamic University Malaysia, Malaysia................................... 539, 558 Martini, Ricardo / Federal University of Santa Maria, Brazil........................................................ 1077 McCrickard, Scott / Virginia Tech, USA............................................................................................... 459 Melo, Julio cesar / Universidade Federal do Rio Grande do Norte, Brasil....................................... 397 Menasalvas, Ernestina / Universitad Politecnica, Spain................................................................... 576 Mencagli, Gabriele / University of Pisa, Italy.................................................................................... 617 Menegon, Davide / University of Udine, Italy........................................................................................ 1 Menezes, Célia / Escola Sec. Inf. D. Henrique, Portugal................................................................... 250 Mentens, Nele / Katholieke Universiteit Leuven, Belgium................................................................. 930 Mizzaro, Stefano / University of Udine, Italy........................................................................................ 1 Molina, Arturo / Tecnologico de Monterrey Mexico, Mexico............................................................ 774 Monguet-Fierro, Jose María / Universidad Politecnica de Catalunya, Spain................................. 285 Morales Kluge, Ernesto / Bremer Institut für Produktion und Logistik GmbH, Germany.............. 1226 Moreira, Edson / University of São Paulo, Brazil............................................................................. 522 Moreira, Fernando / Universidade Portucalense, Portugal.............................................................. 250 Moreiras Lorenzo, Alberto / University of A Coruna, Spain.......................................................... 1169 Mourelos Sánchez, Iván / University of A Coruna, Spain............................................................... 1169 Naessens, Vincent / Katholieke Hogeschool Sint-Lieven, Belgium.................................................. 1246 Naranjo, Juan Álvaro Muñoz / Universidad de Almería, Spain....................................................... 188 Nazzi, Elena / University of Copenhagen, Denmark.............................................................................. 1 Ndlovu, Mandla / Botswana Accountancy College, Botswana............................................................ 48 Nieto Riveiro, Laura / University of A Coruna, Spain..................................................................... 1169 Noel, Victor / Paul Sabatier University, France............................................................................... 1056 Onori, Mauro / The Royal Institute of Technology, Sweden............................................................... 821 Osório Liberato, Nuno André / UTAD, Portugal.............................................................................. 881 Padilla Zea, Natalia / University of Granada, Spain......................................................................... 368 Pallotta, Vincenzo / Webster University, Switzerland........................................................................ 689 Parguiñas Portas, Cesar / University of Vigo, Spain......................................................................... 445 Pereira Loureiro, Javier / University of A Coruna, Spain............................................................... 1169 Pérez-Guerrero, María Luisa / Universidad Politecnica de Catalunya, Spain................................ 285 Perilli, Michele / University of Foggia, Italy........................................................................................ 31 Piotrowski, Jakub / Bremer Institut für Produktion und Logistik, Germany..................................... 738 Poggi, Agostino / Università degli Studi di Parma, Italy.................................................................... 343 Pose, Mariña / University of Santiago Compostela, Spain............................................................... 1182
Pousada García, Thais / University of A Coruna, Spain................................................................. 1169 Pulkkis, Göran / Arcada University of Applied Sciences, Finland.................................................... 952 Quental, Carlos / Polytechnic Institute of Viseu, Portugal................................................................ 974 Ramos, Fernando / University of Aveiro, Portugal............................................................................ 414 Rangel, Víctor / National Autonomous University of Mexico, México.............................................. 595 Reis, Elizabeth / UNIDE, ISCTE – Lisbon University Institute, Portugal......................................... 805 Rensleigh, Chris / University of Johannesburg, South Africa.............................................................. 48 Ribagorda, Arturo / Carlos III University of Madrid, Spain............................................................. 894 Rijo, Rui / IPLeiria, Portugal............................................................................................................. 487 Rodrigues, Vitor / Movensis, Portugal............................................................................................... 719 Rodriguez, Ismael Bouassida / Université de Toulouse, France..................................................... 1056 Rodríguez-Díaz, Francisco / University of Granada, Spain.............................................................. 368 Rodriguez-Sanchez, Cristina / Universidad Rey Juan Carlos, Spain............................................... 472 Romero González, Rubén / University of Vigo, Spain...................................................................... 445 Ruthenbeck, Carmen / Bremer Institut für Produktion und Logistik, Germany............................... 738 Sadigh, Bahram Lotfi / Middle East Technical University, Turkey................................................... 649 Saldaña-García, Carmina / Universidad de Barcelona, Spain......................................................... 285 Salleh, M. F. M. / Universiti Sains Malaysia, Malaysia..................................................................... 157 Sánchez Chao, Castor / University of Vigo, Spain............................................................................. 445 Sánchez Vidales, Miguel Angel / Universidad Pontificia de Salamanca, Spain............................... 216 Sánchez, Montserrat Mateos / Universidad Pontificia de Salamaca, Spain.................................... 216 Santos, David J. / Universidad San Pablo-CEU, Spain..................................................................... 994 Saraiva, Melissa / University of Aveiro, Portugal.............................................................................. 414 Schmidt, Doug / Vanderbilt University, USA...................................................................................... 502 Schneider, Claudio / Universidade Federal do Rio Grande do Norte, Brasil................................... 397 Scholz-Reiter, Bernd / Bremer Institut für Produktion und Logistik, Germany................................. 738 Sena, Hugo / Universidade Federal do Rio Grande do Norte, Brasil................................................ 397 Sendra, Sandra / Polytechnic University of Valencia, Spain........................................................... 1155 Sens, Pierre / University Paris 6, France......................................................................................... 1039 Serrano, Luís / Polithecnic Institute Leiria, Portugal........................................................................ 703 Sibilla, Michelle / Paul Sabatier University, France........................................................................ 1056 Sidek, Othman / Universiti Sains Malaysia, Malaysia...................................................................... 157 Silva, Lidia / University of Aveiro, Portugal....................................................................................... 414 Silva, Manuel / University Coimbra, Portugal................................................................................... 703 Simões, Diogo / Movensis, Portugal................................................................................................... 719 Soares Peres Correia, Emanuel / UTAD, Portugal........................................................................... 881 Steenhaut, Kris / Vrije Universiteit Brussel, Belgium........................................................................ 930 Stojmenovic, Milos / University of Ottawa, Canada............................................................................ 16 Tatara, Naoe / Norwegian Centre for Integrated Care and Telemedicine, Norway........................... 136 Teixeira, Jorge / University of Aveiro, Portugal................................................................................. 414 Tessier, Catherine / ONERA Centre de Toulouse – DCSD, France................................................. 1056 Thoben, Klaus-Dieter / Bremer Institut für Produktion und Logistik GmbH, Germany................. 1226 Tiago, Maria Borges / University of the Azores, Portugal................................................................. 327 Tomaiuolo, Michele / Università degli Studi di Parma, Italy............................................................ 343
Touhafi, Abdellah / Erasmushogheschool Brussel, Belgium...................................................... 930, 994 Turner, Hamilton / Vanderbilt University, USA................................................................................. 502 Ünver, Özgür / TOBB-University of Economics and Technology, Turkey.......................................... 649 Vanneschi, Marco / University of Pisa, Italy...................................................................................... 617 Vanni, Renata Maria / University of São Paulo, Brazil.................................................................... 522 Vassena, Luca / University of Udine, Italy............................................................................................. 1 Vázquez, José Manuel / Universidad San Pablo-CEU, Spain........................................................... 994 Veiga, Luis / INESC ID / Technical University of Lisbon, Portugal................................................... 719 Veiga, Nuno / IPLeiria, Portugal........................................................................................................ 487 Vicente, Paula / UNIDE, ISCTE – Lisbon University Institute, Portugal.......................................... 805 Viehland, Dennis / Massey University, New Zealand......................................................................... 314 Villaseñor, Luis / CICESE Research Centre, México......................................................................... 595 Vuokko, Riikka / Åbo Akademi University, Finland........................................................................ 1119 Wang, Zhonghai / Michigan Tech University, USA........................................................................... 115 Weyn, Maarten / Artesis University College of Antwerpen, Belgium................................................ 539 White, Jules / Vanderbilt University, USA.......................................................................................... 502 Williams, Michael / Pepperdine University, USA............................................................................ 1213 Wilson, Greg / Virginia Tech, USA......................................................................................................... 459 Yahya, Abid / Universiti Malaysia Perlis, Malaysia.......................................................................... 157 Yokoyama, Roberto / University of São Paulo, Brazil...................................................................... 522 Zanda, Andrea / Universitad Politecnica, Spain............................................................................... 576 Zaščerinska, Jeļena / University of Latvia, Latvia............................................................................. 760 Zekavat, Seyed (Reza) / Michigan Tech University, USA.................................................................. 115 Zhang, Chongming / Shanghai Normal University, China................................................................ 237
Table of Contents
Foreword . ............................................................................................................................................. lx Preface . ..............................................................................................................................................lxiii Acknowledgment............................................................................................................................. lxxxv Volume I Section 1 Mobile Technologies Chapter 1 Evaluating the Context Aware Browser: A Benchmark for Proactive, Mobile, and Contextual Web Search............................................................................................................................ 1 Davide Menegon, University of Udine, Italy Stefano Mizzaro, University of Udine, Italy Elena Nazzi, University of Copenhagen, Denmark Luca Vassena, University of Udine, Italy Chapter 2 Routing in Wireless Ad Hoc and Sensor Networks............................................................................... 16 Milos Stojmenovic, University of Ottawa, Canada Chapter 3 Mobile Ad Hoc Networks: Protocol Design and Implementation......................................................... 31 Crescenzio Gallo, University of Foggia, Italy Michele Perilli, University of Foggia, Italy Michelangelo De Bonis, University of Foggia, Italy
Chapter 4 Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa............................................................................................................................ 48 Bwalya Kelvin Joseph, University of Johannesburg, South Africa Chris Rensleigh, University of Johannesburg, South Africa Mandla Ndlovu, Botswana Accountancy College, Botswana Chapter 5 Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs: Absorptive Capacity Limitations........................................................................................................... 65 Kathryn J. Hayes, University of Western Sydney, Australia Ross Chapman, Deakin University Melbourne, Australia Chapter 6 Providing Ubiquitous Access to Synthetic Sign Language Contents over Multiple Platforms............. 83 Fernando López-Colino, Universidad Autónoma de Madrid, Spain Jose Colás, Universidad Autónoma de Madrid, Spain Chapter 7 The Impact of MIMO Communication on Non-Frequency Selective Channels Performance............ 100 Andreas Ahrens, Hochschule Wismar, Germany César Benavente-Peces, Universidad Politécnica de Madrid, Spain Chapter 8 Node Localization in Ad-Hoc Networks.............................................................................................. 115 Zhonghai Wang, Michigan Tech University, USA Seyed (Reza) Zekavat, Michigan Tech University, USA Chapter 9 Wireless and Mobile Technologies Improving Diabetes Self-Management........................................ 136 Eirik Årsand, Norwegian Centre for Integrated Care and Telemedicine, Norway Naoe Tatara, Norwegian Centre for Integrated Care and Telemedicine, Norway Gunnar Hartvigsen, University of Tromsø, Norway Chapter 10 Adaptive Multicarrier Frequency Hopping Spread Spectrum Combined with Channel Coding........ 157 Othman Sidek, Universiti Sains Malaysia, Malaysia Abid Yahya, Universiti Malaysia Perlis, Malaysia Farid Ghani, Universiti Malaysia Perlis, Malaysia R. Badlishah Ahmad, Universiti Malaysia Perlis, Malaysia M. F. M. Salleh, Universiti Sains Malaysia, Malaysia
Chapter 11 Key Adoption Challenges and Issues of B2B E-Commerce in the Healthcare Sector........................ 175 Chad Lin, Curtin University of Technology, Australia Hao-Chiang Koong Lin, National University of Tainan, Taiwan Geoffrey Jalleh, Curtin University of Technology, Australia Yu-An Huang, National Chi Nan University, Taiwan Chapter 12 A Pervasive Polling Secret-Sharing Based Access Control Protocol for Sensitive Information......... 188 Juan Álvaro Muñoz Naranjo, Universidad de Almería, Spain Justo Peralta López, Universidad de Almería, Spain Juan Antonio López Ramos, Universidad de Almería, Spain Chapter 13 Mobile Location-Based Recommenders: An Advertisement Case Study............................................ 203 Mahsa Ghafourian, University of Pittsburgh, USA Hassan Karimi, University of Pittsburgh, USA Chapter 14 Success Cases for Mobile Devices in a Real University Scenario...................................................... 216 Montserrat Mateos Sánchez, Universidad Pontificia de Salamaca, Spain Roberto Berjón Gallinas, Universidad Pontificia de Salamanca, Spain Encarnación Beato Gutierrez, Universidad Pontificia de Salamanca, Spain Miguel Angel Sánchez Vidales, Universidad Pontificia de Salamanca, Spain Ana María Fermoso García, Universidad Pontificia de Salamanca, Spain Chapter 15 Event Detection in Wireless Sensor Networks.................................................................................... 237 Sohail Anwar, Penn State University, USA Chongming Zhang, Shanghai Normal University, China Chapter 16 M-English Podcast: A Tool for Mobile Devices.................................................................................. 250 Célia Menezes, Escola Sec. Inf. D. Henrique, Portugal Fernando Moreira, Universidade Portucalense, Portugal Chapter 17 Public Safety Networks........................................................................................................................ 267 Giuliana Iapichino, EURECOM, France Daniel Câmara, EURECOM, France Christian Bonnet, EURECOM, France Fethi Filali, EURECOM, Qatar
Chapter 18 Mobile Applications as Mobile Learning and Performance Support Tools in Psychotherapy Activitites..................................................................................................................... 285 María Luisa Pérez-Guerrero, Universidad Politecnica de Catalunya, Spain Jose María Monguet-Fierro, Universidad Politecnica de Catalunya, Spain Carmina Saldaña-García, Universidad de Barcelona, Spain Chapter 19 CampusLocator: A Mobile Location-Based Service for Learning Resources..................................... 298 Hassan Karimi, University of Pittsburgh, USA Mahsa Ghafourian, University of Pittsburgh, USA Chapter 20 The Future of WiMAX......................................................................................................................... 314 Dennis Viehland, Massey University, New Zealand Sheenu Chawla, SUSH Global Solutions, New Zealand Chapter 21 Determinants of Loyalty Intention in Portuguese Mobile Market....................................................... 327 Maria Borges Tiago, University of the Azores, Portugal Francisco Amaral, University of the Azores, Portugal Chapter 22 Mobile Agents: Concepts and Technologies........................................................................................ 343 Agostino Poggi, Università degli Studi di Parma, Italy Michele Tomaiuolo, Università degli Studi di Parma, Italy Chapter 23 Vehicular Delay Tolerant Networks..................................................................................................... 356 Daniel Câmara, EURECOM Sophia Antipolis, France Nikolaos Frangiadakis, University of Maryland, USA Fethi Filali, QU Wireless Innovations Center, Qatar Christian Bonnet, EURECOM Sophia Antipolis, France Chapter 24 Monitoring the Learning Process through the Use of Mobile Devices............................................... 368 Francisco Rodríguez-Díaz, University of Granada, Spain Natalia Padilla Zea, University of Granada, Spain Marcelino Cabrera, University of Granada, Spain
Chapter 25 The Making of Nomadic Work: Understanding the Mediational Role of ICTs................................... 381 Aparecido Fabiano Pinatti de Carvalho, University of Limerick, Republic of Ireland Luigina Ciolfi, University of Limerick, Republic of Ireland Breda Gray, University of Limerick, Republic of Ireland Chapter 26 I-Gate: Interperception – Get all the Environments............................................................................. 397 Rummenigge Dantas, Universidade Federal do Rio Grande do Norte, Brasil Luiz Marcos Gonçalves, Universidade Federal do Rio Grande do Norte, Brasil Claudio Schneider, Universidade Federal do Rio Grande do Norte, Brasil Aquiles Burlamaqui, Universidade Federal do Rio Grande do Norte, Brasil Ricardo Dias, Universidade Federal do Rio Grande do Norte, Brasil Hugo Sena, Universidade Federal do Rio Grande do Norte, Brasil Julio cesar Melo, Universidade Federal do Rio Grande do Norte, Brasil Chapter 27 CONNECTOR: A Geolocated Mobile Social Service......................................................................... 414 Pedro Almeida, University of Aveiro, Portugal Jorge Abreu, University of Aveiro, Portugal Margarida Almeida, University of Aveiro, Portugal Maria Antunes, University of Aveiro, Portugal Lidia Silva, University of Aveiro, Portugal Melissa Saraiva, University of Aveiro, Portugal Jorge Teixeira, University of Aveiro, Portugal Fernando Ramos, University of Aveiro, Portugal Chapter 28 Providing VoIP and IPTV Services in WLANs................................................................................... 426 Miguel Edo, Polytechnic University of Valencia, Spain Alejandro Canovas, Polytechnic University of Valencia, Spain Miguel Garcia, Polytechnic University of Valencia, Spain Jaime Lloret, Polytechnic University of Valencia, Spain Chapter 29 SIe-Health, e-Health Information System............................................................................................ 445 Juan Carlos González Moreno, University of Vigo, Spain Loxo Lueiro Astray, University of Vigo, Spain Rubén Romero González, University of Vigo, Spain Cesar Parguiñas Portas, University of Vigo, Spain Castor Sánchez Chao, University of Vigo, Spain
Chapter 30 Combining Location Tracking and RFID Tagging toward an Improved Research Infrastructure...........459 Greg Wilson, Virginia Tech, USA Scott McCrickard, Virginia Tech, USA Chapter 31 Model and Infrastructure for Communications in Context-Aware Services........................................ 472 Cristina Rodriguez-Sanchez, Universidad Rey Juan Carlos, Spain Susana Borromeo, Universidad Rey Juan Carlos, Spain Juan Hernandez-Tamames, Universidad Rey Juan Carlos, Spain Chapter 32 Network Mobility and Mobile Applications Development................................................................. 487 Rui Rijo, IPLeiria, Portugal Nuno Veiga, IPLeiria, Portugal Silvio Bernardes, IPLeiria, Portugal Chapter 33 Building Mobile Sensor Networks Using Smartphones and Web Services: Ramifications and Development Challenges.............................................................................................................. 502 Hamilton Turner, Vanderbilt University, USA Jules White, Vanderbilt University, USA Brian Dougherty, Vanderbilt University, USA Doug Schmidt, Vanderbilt University, USA Chapter 34 Technologies to Improve the Quality of Handovers: Ontologies, Contexts and Mobility Management.......................................................................................................................... 522 Edson Moreira, University of São Paulo, Brazil Bruno Kimura, University of São Paulo, Brazil Renata Maria Vanni, University of São Paulo, Brazil Roberto Yokoyama, University of São Paulo, Brazil Chapter 35 Making Location-Aware Computing Working Accurately in Smart Spaces....................................... 539 Teddy Mantoro, International Islamic University Malaysia, Malaysia Media Ayu, International Islamic University Malaysia, Malaysia Maarten Weyn, Artesis University College of Antwerpen, Belgium Chapter 36 User Pro-Activities Based on Context History.................................................................................... 558 Teddy Mantoro, International Islamic University Malaysia, Malaysia Media Ayu, International Islamic University Malaysia, Malaysia
Section 2 Emerging Technologies Chapter 37 Research Challenge of Locally Computed Ubiquitous Data Mining.................................................. 576 Aysegul Cayci, Sabanci University, Turkey João Bártolo Gomes, Universitad Politecnica, Spain Andrea Zanda, Universitad Politecnica, Spain Ernestina Menasalvas, Universitad Politecnica, Spain Santiago Eibe, Universitad Politecnica, Spain Chapter 38 Emerging Wireless Networks for Social Applications......................................................................... 595 Raúl Aquino, University of Colima, México Luis Villaseñor, CICESE Research Centre, México Víctor Rangel, National Autonomous University of Mexico, México Miguel García, University of Colima, México Artur Edwards, University of Colima, México Chapter 39 An Approach to Mobile Grid Platforms for the Development and Support of Complex Ubiquitous Application........................................................................................................ 617 Carlo Bertolli, University of Pisa, Italy Daniele Buono, University of Pisa, Italy Gabriele Mencagli, University of Pisa, Italy Marco Vanneschi, University of Pisa, Italy Chapter 40 Towards a Programming Model for Ubiquitous Computing............................................................... 634 Jorge Barbosa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Fabiane Dillenburg, Universidade Federal do Rio Grande do Sul, Brazil Alex Garzão, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Gustavo Lermen, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Cristiano Costa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Volume II Chapter 41 An Agent-Based Operational Virtual Enterprise Framework Enabled by RFID................................. 649 Özgür Ünver, TOBB-University of Economics and Technology, Turkey Bahram Lotfi Sadigh, Middle East Technical University, Turkey
Chapter 42 Ontological Dimensions of Semantic Mobile Web 2.0: First Principles............................................. 667 Gonzalo Aranda-Corral, University of Sevilla, Spain Joaquín Borrego-Díaz, University of Sevilla, Spain Chapter 43 Unobtrusive Interaction with Mobile and Ubiquitous Computing Systems through Kinetic User Interfaces..................................................................................................................................... 689 Vincenzo Pallotta, Webster University, Switzerland Chapter 44 Impact of Advances on Computing and Communication Systems in Automotive Testing................. 703 Luís Serrano, Polithecnic Institute Leiria, Portugal José Costa, University Coimbra, Portugal Manuel Silva, University Coimbra, Portugal Chapter 45 RFID and NFC in the Future of Mobile Computing........................................................................... 719 Diogo Simões, Movensis, Portugal Vitor Rodrigues, Movensis, Portugal Luis Veiga, INESC ID / Technical University of Lisbon, Portugal Paulo Ferreira, INESC ID / Technical University of Lisbon, Portugal Chapter 46 A Multi-Loop Development Process for a Wearable Computing System in Autonomous Logistics......................................................................................................................... 738 Jakub Piotrowski, Bremer Institut für Produktion und Logistik, Germany Carmen Ruthenbeck, Bremer Institut für Produktion und Logistik, Germany Florian Harjes, Bremer Institut für Produktion und Logistik, Germany Bernd Scholz-Reiter, Bremer Institut für Produktion und Logistik, Germany Section 3 Critical Success Factors Chapter 47 Collaboration within Social Dimension of Computing: Theoretical Background, Empirical Findings and Practical Development.................................................................................. 760 Andreas Ahrens, University of Technology, Business and Design, Germany Jeļena Zaščerinska, University of Latvia, Latvia Olaf Bassus, University of Technology, Business and Design, Germany
Chapter 48 Critical Factors in Defining the Mobile Learning Model: An Innovative Process for Hybrid Learning at the Tecnologico de Monterrey, a Mexican University......................................... 774 Violeta Chirino-Barceló, Tecnologico de Monterrey Mexico, Mexico Arturo Molina, Tecnologico de Monterrey Mexico, Mexico Chapter 49 Critical Human Factors on Mobile Applications for Tourism and Entertainment............................... 793 Pedro Campos, University of Madeira, Portugal Chapter 50 Internet Surveys: Opportunities and Challenges.................................................................................. 805 Paula Vicente, UNIDE, ISCTE – Lisbon University Institute, Portugal Elizabeth Reis, UNIDE, ISCTE – Lisbon University Institute, Portugal Chapter 51 Evolvable Production Systems: A Coalition-Based Production Approach.......................................... 821 Marcus Bjelkemyr, The Royal Institute of Technology, Sweden Antonio Maffei, The Royal Institute of Technology, Sweden Mauro Onori, The Royal Institute of Technology, Sweden Section 4 New Business Models Chapter 52 Viable Business Models for M-Commerce: The Key Components..................................................... 837 Jiaxiang Gan, University of Auckland, New Zealand Jairo A. Gutiérrez, Universidad Tecnológica de Bolívar, Colombia Chapter 53 A Service-Based Framework to Model Mobile Enterprise Architectures........................................... 853 Jose Delgado, Instituto Superior Técnico, Portugal Chapter 54 Research-Based Insights Inform Change in IBM M-Learning Strategy............................................. 871 Nabeel Ahmad, IBM Center for Advanced Learning, USA Chapter 55 Location Based E-Commerce System: An Architecture...................................................................... 881 Nuno André Osório Liberato, UTAD, Portugal João Eduardo Quintela Alves de Sousa Varajão, UTAD, Portugal Emanuel Soares Peres Correia, UTAD, Portugal Maximino Esteves Correia Bessa, UTAD, Portugal
Section 5 Security Chapter 56 Overview of Security Issues in Vehicular Ad-Hoc Networks.............................................................. 894 José María De Fuentes, Carlos III University of Madrid, Spain Ana Isabel González-Tablas, Carlos III University of Madrid, Spain Arturo Ribagorda, Carlos III University of Madrid, Spain Chapter 57 Modelling of Location-Aware Access Control Rules.......................................................................... 912 Michael Decker, Karlsruhe Institute of Technology (KIT), Germany Chapter 58 Secure Techniques for Remote Reconfiguration of Wireless Embedded Systems.............................. 930 Abdellah Touhafi, Vrije Universiteit Brussel, Belgium An Braeken, Erasmushogeschool Brussel, Belgium Gianluca Cornetta, Universidad San Pablo-CEU, Spain Nele Mentens, Katholieke Universiteit Leuven, Belgium Kris Steenhaut, Vrije Universiteit Brussel, Belgium Chapter 59 Secure Routing and Mobility in Future IP Networks.......................................................................... 952 Kaj Grahn, Arcada University of Applied Sciences, Finland Jonny Karlsson, Arcada University of Applied Sciences, Finland Göran Pulkkis, Arcada University of Applied Sciences, Finland Section 6 Applications, Surveys and Case Studies Chapter 60 Evaluation of a Mobile Platform to Support Collaborative Learning: Case Study............................. 974 Carlos Quental, Polytechnic Institute of Viseu, Portugal Luis Gouveia, University Fernando Pessoa, Portugal Chapter 61 Power Issues and Energy Scavenging in Mobile Wireless Ad-Hoc and Sensor Networks................. 994 Gianluca Cornetta, Universidad San Pablo-CEU, Spain Abdellah Touhafi, Erasmushogheschool Brussel, Belgium David J. Santos, Universidad San Pablo-CEU, Spain José Manuel Vázquez, Universidad San Pablo-CEU, Spain
Chapter 62 A Low Cost Wireless Sensors Network with Low-Complexity and Fast-Prototyping...................... 1021 João Paulo Carmo, University of Minho, Portugal José Higino Correia, University of Minho, Portugal Chapter 63 Unreliable Failure Detectors for Mobile Ad-Hoc Networks.............................................................. 1039 Luciana Arantes, University Paris 6, France Fabíola Greve, Federal University of Bahia, Brazil Pierre Sens, University Paris 6, France Chapter 64 Mission-Aware Adaptive Communication for Collaborative Mobile Entities................................... 1056 Jérôme Lacouture, Université de Toulouse, France Ismael Bouassida Rodriguez, Université de Toulouse, France Jean-Paul Arcangeli, Paul Sabatier University, France Christophe Chassot, Université de Toulouse, France Thierry Desprats, Paul Sabatier University, France Khalil Drira, Université de Toulouse, France Francisco Garijo, Université de Toulouse, France Victor Noel, Paul Sabatier University, France Michelle Sibilla, Paul Sabatier University, France Catherine Tessier, ONERA Centre de Toulouse – DCSD, France Chapter 65 OntoHealth: An Ontology Applied to Pervasive Hospital Environments.......................................... 1077 Giovani Librelotto, Federal University of Santa Maria, Brazil Iara Augustin, Federal University of Santa Maria, Brazil Jonas Gassen, Federal University of Santa Maria, Brazil Guilherme Kurtz, Federal University of Santa Maria, Brazil Leandro Freitas, Federal University of Santa Maria, Brazil Ricardo Martini, Federal University of Santa Maria, Brazil Renato Azevedo, Federal University of Santa Maria, Brazil Chapter 66 Adoption of Mobile and Information Technology in an Energy Utility in Brazil............................. 1091 Osvaldo Garcia, Pontificia Universidade Católica do PR, Brazil Maria Cunha, Pontificia Universidade Católica do PR, Brazil
Chapter 67 Infrastructures for Development of Context-Aware Mobile Applications......................................... 1104 Hugo Feitosa de Figueirêdo, University of Campina Grande, Brazil Tiago Eduardo da Silva, University of Campina Grande, Brazil Anselmo Cardoso de Paiva, University of Maranhão, Brazil José Eustáquio Rangel de Queiroz, University of Campina Grande, Brazil Cláudio De Souza Baptista, University of Campina Grande, Brazil Chapter 68 A Practice Perspective on Transforming Mobile Work..................................................................... 1119 Riikka Vuokko, Åbo Akademi University, Finland Chapter 69 Data Replication Support for Collaboration in Mobile and Ubiquitous Computing Environments.......... 1132 João Barreto, INESC-ID/Technical University Lisbon, Portugal Paulo Ferreira, INESC-ID/Technical University Lisbon, Portugal Chapter 70 Providing Outdoor and Indoor Ubiquity with WLANs..................................................................... 1155 Diana Bri, Polytechnic University of Valencia, Spain Hugo Coll, Polytechnic University of Valencia, Spain Sandra Sendra, Polytechnic University of Valencia, Spain Jaime Lloret, Polytechnic University of Valencia, Spain Chapter 71 In-TIC for Mobile Devices: Support System for Communication with Mobile Devices for the Disabled.................................................................................................................................. 1169 Cristina Diaz Busch, University of A Coruna, Spain Alberto Moreiras Lorenzo, University of A Coruna, Spain Iván Mourelos Sánchez, University of A Coruna, Spain Betania Groba González, University of A Coruna, Spain Thais Pousada García, University of A Coruna, Spain Laura Nieto Riveiro, University of A Coruna, Spain Javier Pereira Loureiro, University of A Coruna, Spain Chapter 72 New Ways to Buy and Sell: An Information Management Web System for the Commercialization of Agricultural Products from Family Farms without Intermediaries................ 1182 Carlos Ferrás, University of Santiago Compostela, Spain Yolanda García, University of Santiago Compostela, Spain Mariña Pose, University of Santiago Compostela, Spain
Chapter 73 Broadcast Quality Video Contribution in Mobility........................................................................... 1199 José Ramón Cerquides Bueno, University of Seville, Spain Antonio Foncubierta Rodriguez, University of Seville, Spain Chapter 74 Mobile Device Selection in Higher Education: iPhone vs. iPod Touch............................................ 1213 C. Brad Crisp, Abilene Christian University, USA Michael Williams, Pepperdine University, USA Chapter 75 Design of Wearable Computing Systems for Future Industrial Environments.................................. 1226 Pierre Kirisci, Bremer Institut für Produktion und Logistik GmbH, Germany Ernesto Morales Kluge, Bremer Institut für Produktion und Logistik GmbH, Germany Emanuel Angelescu, Bremer Institut für Produktion und Logistik GmbH, Germany Klaus-Dieter Thoben, Bremer Institut für Produktion und Logistik GmbH, Germany Chapter 76 Extending the Scope of eID Technology: Threats and Opportunities in a Commercial Setting........ 1246 Vincent Naessens, Katholieke Hogeschool Sint-Lieven, Belgium Bart De Decker, Katholieke Universiteit Leuven, Belgium Chapter 77 Mobility and Connectivity: On the Character of Mobile Information Work..................................... 1262 Victor Gonzalez, University of Manchester, UK Antonis Demetriou, University of Manchester, UK
Detailed Table of Contents
Foreword . ............................................................................................................................................. lx Preface . ..............................................................................................................................................lxiii Acknowledgment............................................................................................................................. lxxxv Section 1 Mobile Technologies Chapter 1 Evaluating the Context Aware Browser: A Benchmark for Proactive, Mobile, and Contextual Web Search............................................................................................................................ 1 Davide Menegon, University of Udine, Italy Stefano Mizzaro, University of Udine, Italy Elena Nazzi, University of Copenhagen, Denmark Luca Vassena, University of Udine, Italy Chapter 1 discusses the evaluation of highly interactive and novel context-aware system with a methodology based on a TREC-like benchmark. The authors take as a case study an application for Web content perusal by means of context-aware mobile devices, named Context-Aware Browser. In this application, starting from the representation of the user’s current context, queries are automatically constructed and used to retrieve the most relevant Web contents. Since several alternatives for query construction exist, it is important to compare their effectiveness, and to this aim we developed a TREClike benchmark. The authors present their approach to an early stage evaluation, describing their aims and the techniques applied, underlining for, for the evaluation of context-aware retrieval systems, the benchmark methodology adopted could be an extensible and reliable tool. Chapter 2 Routing in Wireless Ad Hoc and Sensor Networks............................................................................... 16 Milos Stojmenovic, University of Ottawa, Canada Routing is the process of finding a path from a source node to a destination node. Proposed routing schemes can be divided into topological and position based, depending on the availability of geograph-
ic location for nodes. Topological routing may be proactive or reactive, while position based routing consists of greedy approaches applied when a neighbor closer to the destination (than the node currently holding the packet) exists, and recovery schemes otherwise. In order to preserve bandwidth and power which are critical resources in ad hoc and sensor networks, localized approaches are proposed, where each node acts based solely on the location of itself, its neighbors, and the destination. There are various measures of optimality which lead to various schemes which optimize hop count, power, network lifetime, delay, or other metrics. This second chapter describes a uniform solution based on ratio of cost and progress. Chapter 3 Mobile Ad Hoc Networks: Protocol Design and Implementation......................................................... 31 Crescenzio Gallo, University of Foggia, Italy Michele Perilli, University of Foggia, Italy Michelangelo De Bonis, University of Foggia, Italy Mobile communication networks have become an integral part of our society, significantly enhancing communication capabilities. Mobile ad hoc networks (MANETs) extend this capability to any time/ anywhere communication, providing connectivity without the need of an underlying infrastructure. Chapter 2 investigates the new coming realm of mobile ad hoc networks, focusing on research problems related to the design and development of routing protocols, both from a formal and technical point of view. Then the link stability in a high mobility environment is examined, and a route discovery mechanism is analyzed, together with a practical implementation of a routing protocol in ad hoc multirate environments which privileges link stability instead of traditional speed and minimum distance approaches. Chapter 4 Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa............................................................................................................................ 48 Bwalya Kelvin Joseph, University of Johannesburg, South Africa Chris Rensleigh, University of Johannesburg, South Africa Mandla Ndlovu, Botswana Accountancy College, Botswana The convergence of wireless applications presents a greater hope for consolidating e-Government applications even in resource-constrained countries such as those in Africa. This chapter presents an exploratory study that aims at discussing the extent as to how convergence of wireless technologies from different vendors promises to contribute to the consolidation of e-Government applications in Sub-Saharan-Africa (SSA). This is done by reviewing the different adoption stages of ICT and eGovernment in SSA. It looks at challenges facing adoption of wireless technologies (GSMs, Wireless Internet Access, satellite transmission, etc.) across all the socio-economic value chains in SSA. The chapter looks at Botswana and South Africa as case studies by bringing out the different interventions that have been done in the realm of facilitating a conducive environment for the convergence of different wireless technologies. Out of the analysis of legal, regulatory, market and spectrum policies affecting the adoption of wireless communications in SSAs, the chapter draws out recommendations on how to consolidate wireless communications to be adopted in different socio-economic setups (e.g. e-government, e-Health, e-Banking, etc.).
Chapter 5 Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs: Absorptive Capacity Limitations........................................................................................................... 65 Kathryn J. Hayes, University of Western Sydney, Australia Ross Chapman, Deakin University Melbourne, Australia This Chapter 5 considers the potential for absorptive capacity limitations to prevent SME manufacturers benefiting from the implementation of Ambient Intelligence (AmI) technologies. The chapter also examines the role of intermediary organisations in alleviating these absorptive capacity constraints. In order to understand the context of the research, a review of the role of SMEs in the Australian manufacturing industry, plus the impacts of government innovation policy and absorptive capacity constraints in SMEs in Australia is provided. Advances in the development of ICT industry standards, and the proliferation of software and support for the Windows/Intel platform have brought technology to SMEs without the need for bespoke development. The results from the joint European and Australian AmI4-SME projects suggest that SMEs can successfully use “external research sub-units” in the form of industry networks, research organisations and technology providers to offset internal absorptive capacity limitations. Chapter 6 Providing Ubiquitous Access to Synthetic Sign Language Contents over Multiple Platforms............. 83 Fernando López-Colino, Universidad Autónoma de Madrid, Spain Jose Colás, Universidad Autónoma de Madrid, Spain Chapter 6 presents the design of distributed sign language synthesis architecture. The main objective of this design is to adapt the synthesis process to the diversity of user devices. The synthesis process has been divided into several independent modules that can be run either in a dedicated server or in the client device. Depending on the modules assigned to the server or to the client, four different scenarios have been defined. These scenarios may vary from a heavy client design which executes the whole synthesis process, to a light client design similar to a video player. These four scenarios will provide equivalent signed message quality independently of the device’s hardware and software resources. Chapter 7 The Impact of MIMO Communication on Non-Frequency Selective Channels Performance............ 100 Andreas Ahrens, Hochschule Wismar, Germany César Benavente-Peces, Universidad Politécnica de Madrid, Spain Chapter 7 reviews the basic concepts of multiple-input multiple-output (MIMO) communication systems and analyses their performance within non-frequency selective channels. The MIMO system model is established and by applying the singular value decomposition (SVD) to the channel matrix, the whole MIMO system can be transformed into multiple single-input single-output (SISO) channels having unequal gains. In order to analyze the system performance, the quality criteria needed to calculate the error probability of M-ary QAM (Quadrature Amplitude Modulation) are briefly reviewed and used as reference to measure the improvements when applying different signal processing techniques. Bit and power allocation is a well-known technique that allows improvement in the bit-error rate (BER)
by managing appropriately the different properties of the multiple SISO channels. It can be used to balance the BER’s in the multiple SISO channels when minimizing the overall BER. In order to compare the various results, the efficiency of fixed transmission modes is studied in this work regardless of the channel quality. It is demonstrated that only an appropriate number of MIMO layers should be activated when minimizing the overall BER under the constraints of a given fixed date rate. Chapter 8 Node Localization in Ad-Hoc Networks.............................................................................................. 115 Zhonghai Wang, Michigan Tech University, USA Seyed (Reza) Zekavat, Michigan Tech University, USA Chapter 8 introduces node localization techniques in ad-hoc networks including received signal strength (RSS), time-of-arrival (TOA) and direction-of-arrival (DOA). Wireless channels in ad-hoc networks can be categorized as LOS and NLOS. In LOS channels, the majority of localization techniques perform properly. However, in NLOS channels, the performance of these techniques reduces. Therefore, non-line-of-sight (NLOS) identification and mitigation techniques, and localization techniques for NLOS scenarios are briefly reviewed. Chapter 9 Wireless and Mobile Technologies Improving Diabetes Self-Management........................................ 136 Eirik Årsand, Norwegian Centre for Integrated Care and Telemedicine, Norway Naoe Tatara, Norwegian Centre for Integrated Care and Telemedicine, Norway Gunnar Hartvigsen, University of Tromsø, Norway The technological revolution that has created a vast health problem due to a drastic change in lifestyle also holds great potential for individuals to take better care of their own health. This is the focus of the presented overview of current applications, and prospects for future research and innovations. The presented overview and the main goals of the systems included are to utilize ICT as aids in self-management of individual health challenges, for the disease Diabetes, both for Type 1 and Type 2 diabetes. People with diabetes are generally as mobile as the rest of the population, and should have access to mobile technologies for managing their disease. Forty-seven relevant studies and prototypes of mobile, diabetes-specific self-management tools meeting our inclusion criteria have been identified; 27 publicly available products and services, nine relevant patent applications, and 31 examples of other diseaserelated mobile self-management systems are included to provide a broader overview of the state of the art. Finally, the reviewed systems are compared, and future research directions are suggested. Chapter 10 Adaptive Multicarrier Frequency Hopping Spread Spectrum Combined with Channel Coding........ 157 Othman Sidek, Universiti Sains Malaysia, Malaysia Abid Yahya, Universiti Malaysia Perlis, Malaysia Farid Ghani, Universiti Malaysia Perlis, Malaysia R. Badlishah Ahmad, Universiti Malaysia Perlis, Malaysia M. F. M. Salleh, Universiti Sains Malaysia, Malaysia
Chapter 10 presents an adaptive Multicarrier Frequency Hopping Spread Spectrum (MCFH-SS) system employing proposed Quasi Cyclic Low Density Parity Check (QC-LDPC) codes instead of the conventional LDPC codes. A new technique for constructing the QC-LDPC codes based on row division method is proposed. The new codes offer more flexibility in terms of girth, code rates and codeword length. Moreover, a new scheme for channel prediction in MCFH-SS system is also proposed. The technique adaptively estimates the channel conditions and eliminates the need for the system to transmit a request message prior to transmitting the packet data. The proposed adaptive MCFH-SS system uses PN sequences to spread out frequency spectrum, reduce the power spectral density and minimize the jammer effects. Chapter 11 Key Adoption Challenges and Issues of B2B E-Commerce in the Healthcare Sector........................ 175 Chad Lin, Curtin University of Technology, Australia Hao-Chiang Koong Lin, National University of Tainan, Taiwan Geoffrey Jalleh, Curtin University of Technology, Australia Yu-An Huang, National Chi Nan University, Taiwan Although B2B e-commerce provides healthcare organizations a wealth of new opportunities and ways of doing business, it also presents them with a series of challenges. B2B e-commerce adoption remain poorly understood and it is also a relatively under-researched area. Therefore, case studies were conducted to investigate the challenges and issues in adopting and utilizing B2B e-commerce systems in the healthcare sector. The major aims of the study presented in Chapter 11 are to: (a) identify and examine main B2B e-commerce adoption challenges and issues for healthcare organizations; and (b) develop a B2B e-commerce adoption challenges and issues table to assist healthcare organizations in identifying and managing them. Chapter 12 A Pervasive Polling Secret-Sharing Based Access Control Protocol for Sensitive Information......... 188 Juan Álvaro Muñoz Naranjo, Universidad de Almería, Spain Justo Peralta López, Universidad de Almería, Spain Juan Antonio López Ramos, Universidad de Almería, Spain Chapter 12 presents a novel access control mechanism for sensitive information which requires permission from different entities or persons to be accessed. The mechanism consists of a file structure and a protocol which extend the features of the OpenPGP Message Format standard by using secret sharing techniques. Several authors are allowed to work in the same file, while access is blocked for not authorized users. Access control rules can be set indicating the minimum number of authors that need to be gathered together in order to open the file. Furthermore, these rules can be different for each section of the document, allowing collaborative work. Non-repudiation and authentication are achieved by means of a shared signature. The scheme’s features are best appreciated when using it in a mobile scenario. Deployment in such an environment is easy and straight
Chapter 13 Mobile Location-Based Recommenders: An Advertisement Case Study............................................ 203 Mahsa Ghafourian, University of Pittsburgh, USA Hassan Karimi, University of Pittsburgh, USA Mobile devices, including cell phones, capable of geo-positioning (or localization) are paving the way for new computer assisted systems called mobile location-based recommenders (MLBRs). MLBRs are systems that combine information on user’s location with information about user’s interests and requests to provide recommendations that are based on “location”. MLBR applications are numerous and emerging. One MLBR application is in advertisement where stores announce their coupons and users try to find the coupons of their interests nearby their locations through their cell phones. Chapter 13 discusses the concept and characteristics of MLBRs and presents the architecture and components of a MLBR for advertisement. Chapter 14 Success Cases for Mobile Devices in a Real University Scenario...................................................... 216 Montserrat Mateos Sánchez, Universidad Pontificia de Salamaca, Spain Roberto Berjón Gallinas, Universidad Pontificia de Salamanca, Spain Encarnación Beato Gutierrez, Universidad Pontificia de Salamanca, Spain Miguel Angel Sánchez Vidales, Universidad Pontificia de Salamanca, Spain Ana María Fermoso García, Universidad Pontificia de Salamanca, Spain Mobile devices have become a new platform with many possibilities to develop studies and implement projects. The power and current capabilities of these devices besides its market penetration makes applications and services in the area of mobility particularly interesting. Mobile terminals have become small computers, they have an operating system, storage capacity so it is possible to develop applications that run on them. Today these applications are highly valued by users. Nowadays we want not only to talk or send messages by mobile terminal, but also to play games, to buy cinema tickets, to read email… We can bring these capabilities in our pocket. The University may not be aware of this fact. The students, due to their age, are the main users and purchasers. In this sense, Chapter 14 presents three applications developed for mobile devices, that are being used in Universidad Pontificia de Salamanca. All of them work on a university scenario and use different kind of services. Chapter 15 Event Detection in Wireless Sensor Networks.................................................................................... 237 Sohail Anwar, Penn State University, USA Chongming Zhang, Shanghai Normal University, China Wireless Sensor Networks (WSNs) have experienced an amazing evolution during the last decade. Compared with other wired or wireless networks, wireless sensor networks extend the range of data collection and make it possible for us to get information from every corner of the world. The chapter begins with an introduction to WSNs and their applications. Chapter 15 recognizes event detection as a key component for WSN applications. The chapter provides a structured and comprehensive overview of various techniques used for event detection in WSNs. Existing event detection techniques have
been grouped into threshold based and pattern based mechanisms. For each category of event detection mechanism, the chapter surveys some representative technical schemes. The chapter also provides some analyses on the relative strengths and weaknesses of these technical schemes. Towards the end, the trends in the research regarding the event detection in WSNs are described. Chapter 16 M-English Podcast: A Tool for Mobile Devices.................................................................................. 250 Célia Menezes, Escola Sec. Inf. D. Henrique, Portugal Fernando Moreira, Universidade Portucalense, Portugal At the beginning of the 21st century in a world dominated by technology it is essential to enhance and update the school, creating conditions for the students to succeed, consolidating the role of ICT as a key resource for learning and teaching in this new era. In Chapter 16 the authors describe a study that was carried out in a Portuguese school. As a means to overcome some of the existing logistical obstacles in the school, where the possibility of carrying out ICT activities without restrictions was still dreamlike, the podcast was implemented as an m-learning tool. Being aware of the fact that nowadays mobile phones and mp3 players are part of our students’ lives, the authors took advantage of this fact and the podcast was used as a tool to support, to enhance and to motivate students to learn English, used thus as a complement to traditional (face-to-face) learning. Chapter 17 Public Safety Networks........................................................................................................................ 267 Giuliana Iapichino, EURECOM, France Daniel Câmara, EURECOM, France Christian Bonnet, EURECOM, France Fethi Filali, EURECOM, Qatar Disaster can be defined as the onset of an extreme event causing profound damage or loss as perceived by the afflicted people. The networks built in order to detect and handle these events are called Public safety networks (PSNs). These networks have the fundamental role of providing communication and coordination for emergency operations. Many of the problems of the PSN field come from the heterogeneity of systems and agencies involved in the crisis site and from their mobility at the disaster site. The main aim of Chapter 17 is to provide a broad view of the PSN field, presenting the different emergency management phases, PSNs requirements, technologies and some of the future research directions for this field. Chapter 18 Mobile Applications as Mobile Learning and Performance Support Tools in Psychotherapy Activitites..................................................................................................................... 285 María Luisa Pérez-Guerrero, Universidad Politecnica de Catalunya, Spain Jose María Monguet-Fierro, Universidad Politecnica de Catalunya, Spain Carmina Saldaña-García, Universidad de Barcelona, Spain
The purpose of Chapter 18 is the analysis of mobile applications as performance and informal learning support tools that facilitate the development of the psychotherapy process. The “e-therapy” has become a common term to refer the delivery of mental health services, on-line or related to a computer mediated communication between a psychotherapist and the patient. Initially, a background on e-therapy is provided and after the “self-help therapy”–a kind of e-therapy where the concept of patient empowerment is important– is exposed. Then, the integration of mobile devices in the psychotherapy process will be explained considering how their technological features support patient therapeutic activities like behavior assessment and informal mobile learning. The relation of the mobile devices with psychotherapist work activities such as evidence gathering and patient monitoring will also be explained. The chapter includes a discussion on the mobile learning practices as a source of potential strategies that can be applied in the therapeutic field and finally a set of recommendations and future directions are described to explore new lines of research. Chapter 19 CampusLocator: A Mobile Location-Based Service for Learning Resources..................................... 298 Hassan Karimi, University of Pittsburgh, USA Mahsa Ghafourian, University of Pittsburgh, USA Location-based services (LBSs) are impacting different aspects of human’s life. To date, different LBSs have been emerged, each supporting a specific application or service. While some LBSs have aimed at addressing the needs of general populations, such as navigation systems, others have been focused on addressing the needs of specific populations, including kids, youths, elderly, and people with special needs. In recent years, interest in taking a LBS approach in education and learning has grown. The main purpose of such educational LBSs is facilitating a means for learners to be more efficient and effective in their learning activities using their location as the underlying information in decision making. In this chapter, we present a novel LBS, called CampusLocator, whose main goal is to assist students in locating and accessing learning resources including libraries, seminars, and tutorials that are available on a campus. Chapter 20 The Future of WiMAX......................................................................................................................... 314 Dennis Viehland, Massey University, New Zealand Sheenu Chawla, SUSH Global Solutions, New Zealand WiMAX is being promoted as a potential solution to a number of problems that have plagued the wired and wireless broadband industry since it originated. Can WiMAX fulfill this promise in a crowded and competitive market? If so, what factors are critical to its success? Who will use WiMAX and for what purposes? This chapter identifies both the critical success factors that will give WiMAX an edge over other existing wireless technologies and the key applications that will contribute to its success. The top three critical success factors for WiMAX are availability of handset devices and consumer premise equipment, bandwidth speed, and interoperability and standardization. A panel of WiMAX experts concludes that broadband on demand, wireless services provider access, and Voice over IP are the top three killer applications for WiMAX.
Chapter 21 Determinants of Loyalty Intention in Portuguese Mobile Market....................................................... 327 Maria Borges Tiago, University of the Azores, Portugal Francisco Amaral, University of the Azores, Portugal Chapter 21 conceptualizes and highlights the determinants of customers’ loyalty in the Portuguese mobile market. The authors raise questions about the interrelationships of the cost and values dimensions and the consequences of these relationships on customer satisfaction and trust and consequently loyalty among different operators, addressing some recent models. By organizing and synthesizing the major research streams and tests empirically a conceptual framework through a SEM, with data gather in a survey of Portuguese clients, the present study advances knowledge on the nature of the relative importance of different components of loyalty to mobile communications operators. Some useful preliminary insights were produced related to customers’ retention process in primary mobile operator, which appears strongly related to price/quality, followed by the emotional connection to the operator staff and others clients. Nonetheless, a considerable number of issues were left for future research, including the possibility of extending the investigation to other countries. Chapter 22 Mobile Agents: Concepts and Technologies........................................................................................ 343 Agostino Poggi, Università degli Studi di Parma, Italy Michele Tomaiuolo, Università degli Studi di Parma, Italy Current technological advances and the increasing diffusion of its use for scientific, financial and social activities, make Internet the de facto platform for providing worldwide distributed data storage, distributed computing and communication. It creates new opportunities for the development of new kinds of applications, but it will also create several challenges in managing the information distributed on the Internet and in guaranteeing its “on-time” access through the network infrastructures that realize the Internet. Many researchers believed and still believe that the mobile agents could propose several attractive solutions to deal with such challenges and problems. Chapter 22 presents the core concepts of mobile agents, and attempts to provide a clear idea of the possibility of their use by introducing the problems they cope with, the application areas where they provide advantages with respect to other technologies and the available mobile agent technologies. Chapter 23 Vehicular Delay Tolerant Networks..................................................................................................... 356 Daniel Câmara, EURECOM Sophia Antipolis, France Nikolaos Frangiadakis, University of Maryland, USA Fethi Filali, QU Wireless Innovations Center, Qatar Christian Bonnet, EURECOM Sophia Antipolis, France Traditional networks suppose the existence of some path between endpoints, small end to end roundtrip Delay time, and loss ratio. Today, however, new applications, environments and types of devices are challenging these assumptions. In Delay Tolerant Networks (DTNs), an end-to-end path from source to destination may not exist. Nodes may connect and exchange information in an opportunistic
way. Chapter 23 presents a broad overview of DTNs, particularly focusing on Vehicular DTNs, their main characteristics, challenges, and research projects on this field. In the near future, cars are expected to be equipped with devices that will allow them to communicate wirelessly. However, there will be strict restrictions to the duration of their connections with other vehicles, whereas the conditions of their links will greatly vary; DTNs present an attractive solution. Therefore, VDTNs constitute an attractive research field. Chapter 24 Monitoring the Learning Process through the Use of Mobile Devices............................................... 368 Francisco Rodríguez-Díaz, University of Granada, Spain Natalia Padilla Zea, University of Granada, Spain Marcelino Cabrera, University of Granada, Spain It has been substantially proven that computer operation can be learnt at an early age, and that the use of new technologies can improve a child’s learning process. However, the main problem for the teacher continues to be that he/she cannot pay attention to all children at the same time. Sometimes it is necessary to decide which child must be first attended to. It is in this context that we believe our system has the ability to greatly help teachers: we have developed a learning process control system that allows teachers to determine which students have problems, how many times a child has failed, which activities they are working on and other such useful information, in order to decide how to distribute his/ her time. Furthermore, bearing in mind the attention required by kindergarten students, we propose the provision of mobile devices (PDA - Personal Digital Assistant) for teachers, permitting free movement in the classroom and allowing the teacher to continue to help children while information about other students is being received. Therefore if a new problem arises the teacher is immediately notified and can act accordingly. Chapter 25 The Making of Nomadic Work: Understanding the Mediational Role of ICTs................................... 381 Aparecido Fabiano Pinatti de Carvalho, University of Limerick, Republic of Ireland Luigina Ciolfi, University of Limerick, Republic of Ireland Breda Gray, University of Limerick, Republic of Ireland Computer technologies, especially ICT have become ubiquitous in people’s lives. Nowadays, mobile phones, PDAs, laptops and a constellation of software tools are more and more used for a variety of activities carried out in both personal and professional lives. Given the features that these technologies provide and are provided with, for example, connectivity and portability, it can be said that ICTs have the potential to support nomadic work practices which are seen as increasingly characteristic of the knowledge economy. Chapter 25 presents a review of the concept of nomadic work and, based on a broad literature analysis, discusses the ways in which ICTs may empower people who are involved with nomadic work practices. It aims to give a starting point for those who intend to develop further research on technologically-mediated nomadic work practices in the knowledge economy.
Chapter 26 I-Gate: Interperception – Get all the Environments............................................................................. 397 Rummenigge Dantas, Universidade Federal do Rio Grande do Norte, Brasil Luiz Marcos Gonçalves, Universidade Federal do Rio Grande do Norte, Brasil Claudio Schneider, Universidade Federal do Rio Grande do Norte, Brasil Aquiles Burlamaqui, Universidade Federal do Rio Grande do Norte, Brasil Ricardo Dias, Universidade Federal do Rio Grande do Norte, Brasil Hugo Sena, Universidade Federal do Rio Grande do Norte, Brasil Julio cesar Melo, Universidade Federal do Rio Grande do Norte, Brasil Chapter 26 introduces the I-GATE architecture, a new approach, which includes a set of rules and software architecture, to connect users from different interfaces and devices in the same virtual environment, transparently, even with low capacity of resources. The system detects the user resources and provides transformations on the data in order for its visualization in 3D, 2D and textual-only (1D) interfaces. This allows users from any interface to get a connection in the system using any device and to access and exchange information with other users (including ones with other interface types) in a straightforward way, without need to changing hardware or software. The authors formalize the problem, including modeling, implementation, and usage of the system, also introducing some applications that they have created and implemented in order to evaluate the proposal. Authors have used these applications in cell phones, PDAs, Digital Television, and heterogeneous computers, using the same architecture, with success. Chapter 27 CONNECTOR: A Geolocated Mobile Social Service......................................................................... 414 Pedro Almeida, University of Aveiro, Portugal Jorge Abreu, University of Aveiro, Portugal Margarida Almeida, University of Aveiro, Portugal Maria Antunes, University of Aveiro, Portugal Lidia Silva, University of Aveiro, Portugal Melissa Saraiva, University of Aveiro, Portugal Jorge Teixeira, University of Aveiro, Portugal Fernando Ramos, University of Aveiro, Portugal The widespread and availability of increasingly powerful mobile devices is contributing for the incorporation of new services and features on our daily communications and social relationships. In this context, geolocation of users and points of interest in mobile devices may contribute, in a natural way, to support either the mediation of remote conversations as the promotion of face-to-face meetings between users, leveraging social networks. The CONNECTOR system is based on geolocation data (people, content and activities), enabling users to create and develop their personal relations with other members of the CONNECTOR social network. Users, maps, sharing features and multimedia content are actors in this social network allowing CONNECTOR to address the promotion of geolocated social networks driven by physical proximity and common interests among users. Chapter 27 discusses the work undertaken for the conceptualization and development of the CONNECTOR system. Preliminary evaluation results along with usage contexts are also presented. The chapter concludes with a discussion about future developments in geolocation and personalization in mobile communication services.
Chapter 28 Providing VoIP and IPTV Services in WLANs................................................................................... 426 Miguel Edo, Polytechnic University of Valencia, Spain Alejandro Canovas, Polytechnic University of Valencia, Spain Miguel Garcia, Polytechnic University of Valencia, Spain Jaime Lloret, Polytechnic University of Valencia, Spain Nowadays, triple-play services are offered in both wireless and wired networks. The network convergence and the new services such as VoIP and IPTV are a reality. However, the future of these networks will have a different concept, the ubiquity. The solutions must be based on the structures and current environments to carry out those challenges in a correct way. In order to reach this ubiquity, the science community has to take into account that its implementation should not assume a high cost to the user and that the system must comply with the quality of service measurements to satisfy the user. Chapter 28 introduces the main VoIP and IPTV (IP Television) transmission protocols and the compression formats most used as also the bandwidth needed. The goal is to provide ubiquity into multimedia scenarios in WLANs. Authors will carry out tests to guarantee the appropriate values in some network parameters such jitter, delay, number of lost packets and enough effective bandwidth that should be satisfied. They demonstrate the measurements taken from several test benches. They show the parameter values that the devices should perform in order to stay connected from anywhere at any time to these services. Chapter 29 SIe-Health, e-Health Information System............................................................................................ 445 Juan Carlos González Moreno, University of Vigo, Spain Loxo Lueiro Astray, University of Vigo, Spain Rubén Romero González, University of Vigo, Spain Cesar Parguiñas Portas, University of Vigo, Spain Castor Sánchez Chao, University of Vigo, Spain In recent years, the incessant development of new communication technologies has provided a better way for accessing information and a countless amount of useful opportunities. One of the sectors that have a great potential to use and exploit this kind of technologies is the healthcare sector. Nowadays, the application of all these new technologies to support the clinical procedures has taken part in the definition of a new concept known as e-Health. This concept involves a lot of different services related with the medicine/health terms and the information technologies. However, to provide emergency transportation with better care capabilities to the patient is something that still has a lot to improve. Within this context SIe-Health comes into being a software platform oriented for developing Telemedicine solutions. The solution model proposed in this chapter allows remote assistance for a mobile health emergency, integrating in this service electro-medical devices and videoconference services. Chapter 30 Combining Location Tracking and RFID Tagging toward an Improved Research Infrastructure...........459 Greg Wilson, Virginia Tech, USA Scott McCrickard, Virginia Tech, USA
The popularity of mobile computing creates new opportunities for information sharing and collaboration through technologies like radio frequency identification (RFID) tags and location awareness technologies. Chapter 30 discusses how these technologies, which provide subtly different information, can be used together toward increased benefit to users. This work introduces technologies for RFID and location awareness, including a survey of projects. The authors describe advantages of combining these technologies, illustrated through our system, TagIt, that uses these technologies in a traditional research poster environment to provide a rich multimedia experience and encourage ongoing feedback from poster viewers. An overview of TagIt is provided, including user commenting and information sharing capabilities that make use of RFID and location information. User feedback and an expert review highlights how TagIt could benefit authors, information consumers, and the research community, leading to future directions for the research community. Chapter 31 Model and Infrastructure for Communications in Context-Aware Services........................................ 472 Cristina Rodriguez-Sanchez, Universidad Rey Juan Carlos, Spain Susana Borromeo, Universidad Rey Juan Carlos, Spain Juan Hernandez-Tamames, Universidad Rey Juan Carlos, Spain The appearance of concepts such as “Ambient Intelligent”, “Ubiquitous Computing” and “ContextAwareness” is causing the development of a new type of services called “Context-Aware Services” that in turn may affect users of mobile communications. This technology revolution is a complex process because of the heterogeneity of contents, devices, objects, technologies, resources and users that can be coexist at the same local environment. The novel approach in Chapter 31 is the development of a ”Local Infrastructure” in order to provide intelligent, transparent and adaptable services to the user and solves the problem of local context control. Authors present a conceptual model for development of local infrastructure, an architecture design to control the service offered by the local infrastructure. This infrastructure proposed consists of an intelligent device network to link the personal portable device with the contextual services. The device design is modular, flexible, scalable, adaptable and reconfigurable remotely in order to tolerate new demand services whenever is needed. Finally, the result suggests that authors will be able to develop a wide range of new and useful applications, not conceived at origin. Chapter 32 Network Mobility and Mobile Applications Development................................................................. 487 Rui Rijo, IPLeiria, Portugal Nuno Veiga, IPLeiria, Portugal Silvio Bernardes, IPLeiria, Portugal The use of mobile devices with possible connection to the Internet is increasing tremendously. This mobility poses new challenges at various levels, including hardware, network services, and the development of applications. The user searches small and lightweight devices, easy to use, and with vast autonomy in terms of energy. She/He seeks also to connect the Internet “every time, everywhere”, possibly using different access technologies. Given the interface limitations, and processing capabilities of small mobile devices, the software and the operating system used must be necessarily adapted. Chapter 32 overviews the mobility area, provides deep insight in the field, and presents the main existing prob-
lems. Mobility and the development of mobile applications are closed related. The advances in network mobility lead to different approaches in the mobile applications development. The chapter proposes a model for developing mobile applications, based on our research. Chapter 33 Building Mobile Sensor Networks Using Smartphones and Web Services: Ramifications and Development Challenges.............................................................................................................. 502 Hamilton Turner, Vanderbilt University, USA Jules White, Vanderbilt University, USA Brian Dougherty, Vanderbilt University, USA Doug Schmidt, Vanderbilt University, USA Wireless sensor networks are composed of geographically dispersed sensors that work together to monitor physical or environmental conditions. In addition, wireless sensor networks are used in many industrial, social, and regulatory applications, including industrial process monitoring and control, environment and habitat monitoring, healthcare, home automation, and traffic control. Developers of wireless sensor networks face a number of programming and deployment challenges. Chapter 33 shows how smartphones can help reduce the development, operation, and maintenance costs of wireless sensor networks, while also enabling these networks to use web services, high-level programming APIs, and increased hardware capability, such as powerful microprocessors. Moreover, this chapter examines key challenges associated with developing and maintaining a large wireless sensor network and presents a novel smartphone wireless sensor network that uses smartphones as sensor nodes. The work is validated in the context of Wreck Watch, which is a smartphone-based sensor network for detecting traffic accidents that authors use to demonstrate solutions to multiple challenges in current wireless sensor networks. The authors also describe common pitfalls of using smartphones as sensor nodes in wireless sensor networks and summarize how have addressed these pitfalls in Wreck Watch. Chapter 34 Technologies to Improve the Quality of Handovers: Ontologies, Contexts and Mobility Management................................................................................................................... 522 Edson Moreira, University of São Paulo, Brazil Bruno Kimura, University of São Paulo, Brazil Renata Maria Vanni, University of São Paulo, Brazil Roberto Yokoyama, University of São Paulo, Brazil Modern life makes people internet-dependents. They want to move connected and care for always getting the best options for connectivity, hoping between providers. Freedom for choosing providers and the business options which these exchanges can offer are the motivations for Chapter 34. After pointing out some characteristics which make the basics of the current handover technologies, we describe an information infrastructure, based on context and ontologies which can be used to foster an intelligent, efficient and profitable scenario for managing handovers in the Next Generation Networks. Some experiments are described and the potential of using these technologies are evaluated.
Chapter 35 Making Location-Aware Computing Working Accurately in Smart Spaces....................................... 539 Teddy Mantoro, International Islamic University Malaysia, Malaysia Media Ayu, International Islamic University Malaysia, Malaysia Maarten Weyn, Artesis University College of Antwerpen, Belgium In smart environments, making a location-aware personal computing working accurately is a way of getting close to the pervasive computing vision. The best candidate to determine a user location in indoor environment is by using IEEE 802.11 (Wi-Fi) signals, since it is more and more widely available and installed on most mobile devices used by users. Unfortunately, the signal strength, signals quality and noise of Wi-Fi, in worst scenario, it fluctuates up to 33% because of the reflection, refraction, temperature, humidity, the dynamic environment, etc. The authors present in Chapter 35 their current development on a light-weight algorithm, which is easy, simple but robust in producing the determination of user location using WiFi signals. The algorithm is based on “multiple observers” on ηk-Nearest Neighbour. The authors extend the approach in the estimation indoor-user location by using combination of different technologies, i.e. WiFi, GPS, GSM and Accelerometer. The algorithm is based on opportunistic localization algorithm and fuse different sensor data in order to be able to use the data which is available at the user position and processable in a mobile device. Chapter 36 User Pro-Activities Based on Context History.................................................................................... 558 Teddy Mantoro, International Islamic University Malaysia, Malaysia Media Ayu, International Islamic University Malaysia, Malaysia Context-aware computing is a class of mobile computing that can sense its physical environment and adapt its behavior accordingly; it is a component of the ubiquitous or pervasive computing environment that has become apparent with innovations and challenges. Chapter 36 reviews the concept of contextaware computing, with focus on the user activities that benefit from context history. How user activities in the smart environment can make use of context histories in applications that apply the concept of context prediction integrated with user pro-activity is explored. A brief summary of areas which benefit from these technologies as well as corresponding issues are also investigated. Section 2 Emerging Technologies Chapter 37 Research Challenge of Locally Computed Ubiquitous Data Mining.................................................. 576 Aysegul Cayci, Sabanci University, Turkey João Bártolo Gomes, Universitad Politecnica, Spain Andrea Zanda, Universitad Politecnica, Spain Ernestina Menasalvas, Universitad Politecnica, Spain Santiago Eibe, Universitad Politecnica, Spain
Advances in wireless, sensor, mobile and wearable technologies present new challenges for data mining research on providing mobile applications with intelligence. Autonomy and adaptability requirements are the two most important challenges for data mining in this new environment. In this chapter, the authors analyse the challenges of designing ubiquitous data mining services by examining the issues and problems while paying special attention to context and resource awareness. The authors focused on the autonomous execution of a data mining algorithm and analyzed the situational factors that influence the quality of the result. Already existing solutions in this area and future directions of research are also covered. Chapter 38 Emerging Wireless Networks for Social Applications......................................................................... 595 Raúl Aquino, University of Colima, México Luis Villaseñor, CICESE Research Centre, México Víctor Rangel, National Autonomous University of Mexico, México Miguel García, University of Colima, México Artur Edwards, University of Colima, México Chapter 38 describes the implementation and performance evaluation of a novel routing protocol called Pandora, designed for social applications, and that can be implemented in a broad number of devices, such as commercial wireless routers and laptops. It also provides a robust backbone integrating and sharing data, voice and video between computers and mobile devices. Pandora offers great performance with both fixed and mobile devices and includes important features such as: geographic positioning, residual battery energy monitoring, and bandwidth utilization. In addition, Pandora also considers the number of devices attached to the network. Pandora is experimentally evaluated in a testbed with laptops for the first stage and commercial wireless routers for the second stage. The main goal of Pandora is to provide a reliable backbone for social applications requiring a quality of service (QoS) guarantee. With this in mind, the following evaluation of Pandora considers the following types of traffic sources: transport control protocol (TCP), voice, video and user datagram protocol (UDP) without marks. Pandora is also compared with different queuing disciplines, including: priority queuing discipline (PRIO), hierarchical token bucket (HTB) and DSMARK. Finally, an Internet radio transmission is employed to test the network re-configurability. Results show that queuing the PRIO and HTB disciplines, which prioritizes UDP traffic, performed the best. Chapter 39 An Approach to Mobile Grid Platforms for the Development and Support of Complex Ubiquitous Application........................................................................................................ 617 Carlo Bertolli, University of Pisa, Italy Daniele Buono, University of Pisa, Italy Gabriele Mencagli, University of Pisa, Italy Marco Vanneschi, University of Pisa, Italy Several complex and time-critical applications require the existence of novel distributed, heterogeneous and dynamic platforms composed of a variety of fixed and mobile processing nodes and networks. Such platforms, that can be called Pervasive Mobile Grids, aim to merge the features of Pervasive Comput-
ing and High-performance Grid Computing onto a new emerging paradigm. In this chapter we study a methodology for the design and the development of high-performance, adaptive and context-aware applications. Chapter 39 describes a programming model approach, and the authors compare it with other existing research works in the field of Pervasive Mobile Computing, discussing the rationales of the requirements and the features of a novel programming model for the target platforms and applications. In order to exemplify the proposed methodology, the authors introduce the programming framework ASSISTANT, and provide some interesting future directions in this research field. Chapter 40 Towards a Programming Model for Ubiquitous Computing............................................................... 634 Jorge Barbosa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Fabiane Dillenburg, Universidade Federal do Rio Grande do Sul, Brazil Alex Garzão, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Gustavo Lermen, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Cristiano Costa, Universidade do Vale do Rio dos Sinos (Unisinos), Brazil Potentially, in the mobile computing scenario, the users can move in different environments and the applications can automatically explore their surroundings. This kind of context-aware application is emerging, but is not yet widely disseminated. Based on perceived context, the application can modify its behavior. This process, in which software modifies itself according to sensed data, is named Adaptation and constitutes the core of Ubiquitous Computing. The ubiquitous computing scenario brings many new problems such as coping with the limited processing power of mobile devices, frequent disconnections, the migration of code and tasks between heterogeneous devices, and others. Current practical approaches to the ubiquitous computing problem usually rely upon traditional computing paradigms conceived back when distributed applications where not a concern. Holoparadigm (Holo) was proposed as a model to support the development of distributed systems. Based on Holo concepts, a new programming language called HoloLanguage (HoloL) was created. The authors propose the use of Holo for developing and executing ubiquitous applications, explore the HoloL for ubiquitous programming and propose a full platform to develop and execute Holo programs. The execution environment is based on a virtual machine that implements the concepts proposed by Holo. Chapter 41 An Agent-Based Operational Virtual Enterprise Framework Enabled by RFID................................. 649 Özgür Ünver, TOBB-University of Economics and Technology, Turkey Bahram Lotfi Sadigh, Middle East Technical University, Turkey The Virtual Enterprise (VE) is a collaboration model between multiple business partners in a value chain that aims to cope with turbulent business environments, mainly characterized by demand unpredictability, shortening product lifecycles, and intense cost pressures. The VE model is particularly viable and applicable for SME and industry parks containing multiple SMEs that have different vertical competencies. As small firms collaborate effectively under VE model, it will be only possible to emerge products by joining their diverse competencies and mitigate the effects of market turbulence by minimizing their investment. A typical VE model has four phases; opportunity capture, formation, operation, and dissolution. The goal of this chapter is to present a conceptual VE framework, focusing
on operation phase, that incorporates Multi Agent Systems (MAS) and Radio Frequency Identification Systems (RFID) which are emerging from research to industry with a great momentum. First, state of the art for VE and the two key enabling technologies are covered in detail. After presenting conceptual view of the framework, an Information and Communication Technology (ICT) view is also given to enhance technical integration with available industry standards and solutions. Finally, process views of how a VE can operate utilizing agent based and RFID systems in order to fulfill operational requirements, are presented. Chapter 42 Ontological Dimensions of Semantic Mobile Web 2.0: First Principles............................................. 667 Gonzalo Aranda-Corral, University of Sevilla, Spain Joaquín Borrego-Díaz, University of Sevilla, Spain Chapter 42 advances, from the point of view of Knowledge Representation and Reasoning, an analysis of which ontological dimensions are needed to develop Mobile Web 2.0 on top of Semantic Web. This analysis will be particularly focused on social networks and it will try to make an outlook about the new knowledge challenges on this field. Some of these new challenges will be linked to Semantic Web context, while others will be inherent to Semantic Mobile Web 2.0. Chapter 43 Unobtrusive Interaction with Mobile and Ubiquitous Computing Systems through Kinetic User Interfaces..................................................................................................................................... 689 Vincenzo Pallotta, Webster University, Switzerland Unobtrusiveness is a key factor in usability of mobile and ubiquitous computing systems. These systems are made of several ambient and mobile devices whose goal is supporting everyday life users’ activities, hopefully without interfering with them. The chapter addresses the topic of obtrusiveness by assessing its impact in the design of interfaces for mobile and ubiquitous computing systems. Authors discuss how unobtrusive interfaces can be designed by means of Kinetic User Interfaces: an emerging interaction paradigm where input to system is provided through coordinated motion of objects and people in the physical space. Chapter 44 Impact of Advances on Computing and Communication Systems in Automotive Testing................. 703 Luís Serrano, Polithecnic Institute Leiria, Portugal José Costa, University Coimbra, Portugal Manuel Silva, University Coimbra, Portugal A huge amount of information is used nowadays by modern vehicles, and it may be accessed through an On Board Diagnosis (OBD) connection. A technique using the already installed OBD system to communicate with the vehicle together with a Global Position System (GPS) provides reliable data which allow a detailed analysis of real on road tests. Different kinds of circulation circuits (urban, extra-urban and highway) were analyzed in Chapter 44, using the capabilities of OBD II installed on the tested vehicles. OBD provides an important set of information, namely related with data on the engine, fuel
consumption, chassis and auxiliary systems and also on combustion efficiency. The use of GPS in all the road tests performed provides important information to further determine the more sustainable from all the different solutions tested, considering the different situations imposed on each circuit. It is a fact that bench tests or a chassis dynamometer allow a fine control of the operation conditions; however the simulation is not as real as on the road. So the present methodology will allow the possibility to perform tests on the road, allowing enough control on vehicles and providing complete information of the chosen route and of the trip history. This is a possibility that ensures new tools with more reliable data which can give faster answers for the development of high efficiency, economic and environmentally neutral automotive technologies. Chapter 45 RFID and NFC in the Future of Mobile Computing........................................................................... 719 Diogo Simões, Movensis, Portugal Vitor Rodrigues, Movensis, Portugal Luis Veiga, INESC ID / Technical University of Lisbon, Portugal Paulo Ferreira, INESC ID / Technical University of Lisbon, Portugal RFID (Radio Frequency Identification) technology consists of a tag that can be used to identify an animal, a person or a product, and a device responsible for transmitting, receiving and decoding the radio waves. RFID tags work in two different modes: they wake up when they receive a radio wave signal and reflect it (Passive Mode) or they emit their own signal (Active Mode). The tags store information which allows univocally identifying something or someone. That information is stored in an IC (Integrated Circuit) which is connected to an antenna, responsible for transmitting the information. An evolution of this technology is the Near Field Communication (NFC). It consists of a contactless Smart Card technology, based in short-range RFID. Currently, there are mobile phones with NFC embedded in such a way that they work both as a tag and as a NFC reader. These technologies will be widely available both in mobile phones and other devices (e.g. personal digital assistants, etc.) in the near future allowing us to get closer to a ubiquitous and pervasive world. This chapter describes the most important aspects of RFID and NFC technology, illustrating their applicative potential, and provides a vision of the future in which the virtual and real worlds merge together as if an osmosis took place. Chapter 46 A Multi-Loop Development Process for a Wearable Computing System in Autonomous Logistics......................................................................................................................... 738 Jakub Piotrowski, Bremer Institut für Produktion und Logistik, Germany Carmen Ruthenbeck, Bremer Institut für Produktion und Logistik, Germany Florian Harjes, Bremer Institut für Produktion und Logistik, Germany Bernd Scholz-Reiter, Bremer Institut für Produktion und Logistik, Germany Chapter 46 examines a multi-loop development process for a wearable computing system within a new paradigm in logistic applications. The implementation of this system will be demonstrated by an example from the field of autonomous logistics for automobile logistics. The development process is depicted from selecting and combining hardware through to the adjustment to both user and operative environment. Further, this chapter discusses critical success factors like robustness and flexibility. The objective is to present problems and challenges as well as a possible approach to cope with them.
Section 3 Critical Success Factors Chapter 47 Collaboration within Social Dimension of Computing: Theoretical Background, Empirical Findings and Practical Development.................................................................................. 760 Andreas Ahrens, University of Technology, Business and Design, Germany Jeļena Zaščerinska, University of Latvia, Latvia Olaf Bassus, University of Technology, Business and Design, Germany A proper development of computing which penetrate our society more thoroughly with the availability of broadband services is provided by varied cooperative networks. However, the success of social dimension of computing requires collaboration within a multicultural environment to be considered. Aim of Chapter 47 is to analyze collaboration within the social dimension of computing on the pedagogical discourse. The meaning of the key concepts of social dimension of computing, collaboration and its factors is studied within the search for the success of social dimension. The manuscript introduces the study conducted within the Baltic Summer School Technical Informatics and Information Technology in 2009. The conducted explorative research comprises four stages: exploration of the contexts of collaboration, analysis of the students’ needs (content analysis), data processing, analysis and data interpretation, and analysis of the results and elaboration of conclusions and hypothesis for further studies. Chapter 48 Critical Factors in Defining the Mobile Learning Model: An Innovative Process for Hybrid Learning at the Tecnologico de Monterrey, a Mexican University......................................... 774 Violeta Chirino-Barceló, Tecnologico de Monterrey Mexico, Mexico Arturo Molina, Tecnologico de Monterrey Mexico, Mexico Many factors converge when attempting to define the most adequate mobile learning model to be applied in a face-to-face university environment. As far as innovation related processes go, the implementation of mobile learning, implies defining a road map on the basis of strategic planning. It is also important to apply an action research approach in the implementation process of the model. In analyzing in depth this innovative mobile learning process, there are key factors to consider. First, there are factors related to the technology necessary for the implementation of the model—both hard and soft requirements. Second, there are cultural issues related to the use of non-native internet professors of innovative technologies. Finally, there are challenges related to defining, exactly, those educational strategies to be handled through mobile devices. Chapter 48 focuses on the critical factors involved in integrating mobile learning into a hybrid educational model at a Mexican university. Chapter 49 Critical Human Factors on Mobile Applications for Tourism and Entertainment............................... 793 Pedro Campos, University of Madeira, Portugal The purpose of Chapter 49 is to research some principles that can guide the design, development and marketing of mobile applications, with a particular focus on the tourism and entertainment applica-
tion domains. This research also fills a gap concerning impact studies of mobile applications, since the majority of the literature available today is more focused on the design and development process and results. Besides describing a set of novel mobile applications, we aim at providing an overview on innovation processed used, and conducting several experiences, gathering results from questionnaires, surveys, log data and our own observations. Regarding the mobile tourism domain, the author studied the impact of media visibility, the impact of novel interaction paradigms. Regarding the mobile entertainment applications, he focused on studying the impact brought that realism and graphics quality have on mobile games. Chapter 50 Internet Surveys: Opportunities and Challenges.................................................................................. 805 Paula Vicente, UNIDE, ISCTE – Lisbon University Institute, Portugal Elizabeth Reis, UNIDE, ISCTE – Lisbon University Institute, Portugal Internet surveys offer important advantages over traditional survey methods: they can accomplish large samples within a relatively short period of time, questionnaires may have visual and navigational functionalities impossible to implement in paper-and-pencil questionnaires, data is more efficiently processed since it already comes in electronic format and costs can be lower. But the use of the Internet for survey purposes raises important concerns related to population coverage, lack of suitable sampling frames and non-response. Despite its problems, Internet-based surveys are growing and will continue to expand presenting researchers with the challenge of finding the best way to adapt the methods and principles established in survey methodology to this new mode of data collection in order to make best use of it. Chapter 50 describes the positive features of the Internet for survey activity and examines some of the challenges of conducting surveys via the Internet by looking at methodological issues such as coverage, sample selection, non-response and data quality. Chapter 51 Evolvable Production Systems: A Coalition-Based Production Approach.......................................... 821 Marcus Bjelkemyr, The Royal Institute of Technology, Sweden Antonio Maffei, The Royal Institute of Technology, Sweden Mauro Onori, The Royal Institute of Technology, Sweden The purpose of Chapter 51 is to provide broad view of the rationale, fundamental principles, current developments and applications for Evolvable Production Systems (EPS). Special attention is given to how complexity is handled, the use of agent based and wireless technology, and how economical issues are affected by having an evolvable system. The rationale for EPS is based on current road mapping efforts, which have clearly underlined that true industrial sustainability requires far higher levels of system autonomy and adaptivity than what can be achieved within current production system paradigms. Since its inception in 2002 as a next generation of production systems, the EPS concept has been further developed and tested to emerge as a production system paradigm with technological solutions and mechanisms that support sustainability. Technically, EPS is based on the idea of using several re-configurable, process-oriented, agent-based and wireless intelligent modules of low granularity. This allows for a continuous adaption and evolution of the production system and the ability to explore emergent behavior of the system, which are imperative to remain fit with regards to the system environment.
Section 4 New Business Models Chapter 52 Viable Business Models for M-Commerce: The Key Components..................................................... 837 Jiaxiang Gan, University of Auckland, New Zealand Jairo Gutierrez, Universidad Tecnológica de Bolívar, Colombia As mobile applications increase in popularity, the issue of how to build viable business models for the m-commerce industry is becoming a clear priority for both organizations and researchers. In order to address this issue, this chapter reports on five mini cases used as a guideline, and applies the theoretical business model from Chesbrough and Rosenbloom (2002) to each of them to find out the most important components of viable business models for their m-commerce applications. The study then uses cross cases analysis as a research tool to compare and contrast each of the mini cases and to find out how the different organizations fit within the researched theoretical business model. Finally, this chapter confirms that there are 7 important components of viable business models for m-commerce which are: value proposition, market segment, value chain, profit potential, value network, competitive strategy and firm capabilities. This study also highlights the fact that the public visibility of these 7 components is uneven. Some components such as value proposition, value chain, value network and firm’s capabilities are more likely to be presented in public by organizations. However, aspects such as cost structure and profit potential, market segment and competitive strategy are more likely to be hidden from the public due to their commercial sensitivity. Chapter 53 A Service-Based Framework to Model Mobile Enterprise Architectures........................................... 853 Jose Delgado, Instituto Superior Técnico, Portugal Mobility is a relatively recent topic in the enterprise arena, but thanks to the widespread use of cell phones it has already changed much of the business landscape. It should be integrated in enterprise architectures (EAs) as an intrinsic feature and not as an add-on or as an afterthought transition. Current EA frameworks were not designed with mobility in mind and are usually based on the process paradigm, emphasizing functionality. Although the issue of establishing a systematized migration path from a non-mobile EA to a mobile one has already been tackled, the need for mobile-native EA modeling frameworks is still felt. Chapter 53 presents and discusses a resource-based and service-oriented metamodel and EA framework, in which mobility is introduced naturally from scratch, constituting the basis for some guidelines on which EA resources should be mobilized. Several simple scenarios are presented in the light of this metamodel and framework. Chapter 54 Research-Based Insights Inform Change in IBM M-Learning Strategy............................................. 871 Nabeel Ahmad, IBM Center for Advanced Learning, USA Although mobile phones have become an extension of the workplace, organizations are still exploring their effectiveness for employee training and development. A 2009 joint collaborative study between
Columbia University (New York, USA) and IBM of 400 IBM employees’ use of mobile phones revealed unexpected insights into how employees use mobile applications to improve job performance. The findings are reshaping IBM Learning’s mobile technologies strategy for networking, collaboration, and skills improvement. This chapter reveals the study’s results and IBM’s new direction for mlearning, highlighting IBM’s preparedness for a shift in its organizational learning model potentiated by ubiquitous access and mobility. Chapter 55 Location Based E-Commerce System: An Architecture...................................................................... 881 Nuno André Osório Liberato, UTAD, Portugal João Eduardo Quintela Alves de Sousa Varajão, UTAD, Portugal Emanuel Soares Peres Correia, UTAD, Portugal Maximino Esteves Correia Bessa, UTAD, Portugal Location-based mobile services (LBMS) are at present an ever growing trend, as found in the latest and most popular mobile applications launched. They are, indeed, supported by the hasty evolution of mobile devices capabilities; by users demand; and, lastly, by market drive. With e-commerce, products and services started arriving to potential customers through desktop computers, where they can be bought and fast delivered to a given address. However, expressions such as “being mobile”, “always connected”, “anytime anywhere” that already characterize life in the present will certainly continue to do so in the near future. Meanwhile, mobile devices centred commerce services seem to be the next step. Therefore, this chapter presents a system architecture designed for location-based e-commerce systems. These systems, where location plays the most important role, enable a remote products/services search, based in user parameters: after a product search, shops with that products are returned in the search results and are displayed in a map, around the user present location; and services like obtaining more information, reserving and purchasing are made available as well. This concept represents a mix between traditional client-oriented commerce and faceless mass-oriented e-commerce, enabling a proximity-based user-contextualized system, being well capable of conveying significant advantages and facilities to both service-providers/retailers and users. Section 5 Security Chapter 56 Overview of Security Issues in Vehicular Ad-Hoc Networks.............................................................. 894 José María De Fuentes, Carlos III University of Madrid, Spain Ana Isabel González-Tablas, Carlos III University of Madrid, Spain Arturo Ribagorda, Carlos III University of Madrid, Spain Vehicular ad-hoc networks (VANETs) are a promising communication scenario. Several new applications are envisioned, which will improve traffic management and safety. Nevertheless, those applications have stringent security requirements, as they affect road traffic safety. Moreover, VANETs
face several security threats. As VANETs present some unique features (e.g. high mobility of nodes, geographic extension, etc.) traditional security mechanisms are not always suitable. Because of that, a plethora of research contributions have been presented so far. This chapter aims to describe and analyze the most representative VANET security developments. Chapter 57 Modelling of Location-Aware Access Control Rules.......................................................................... 912 Michael Decker, Karlsruhe Institute of Technology, Germany Access control in the domain of information system security refers to the process of deciding whether a particular request made by a user to perform a particular operation on a particular object under the control of the system should be allowed or denied. For example, the access control component of a file server might have to decide whether user “Alice” is allowed to perform the operation “delete” on the object “document.txt”. For traditional access control this decision is based on the evaluation of the identity of the user and attributes of the object. The novel idea of location-aware access control is also to consider the user’s current location which is determined by a location system like GPS. The main purpose of Chapter 57 is to present several approaches for the modeling of location-aware access control rules. Chapter 58 Secure Techniques for Remote Reconfiguration of Wireless Embedded Systems.............................. 930 Abdellah Touhafi, Vrije Universiteit Brussel, Belgium An Braeken, Erasmushogeschool Brussel, Belgium Gianluca Cornetta, Universidad San Pablo-CEU, Spain Nele Mentens, Katholieke Universiteit Leuven, Belgium Kris Steenhaut, Vrije Universiteit Brussel, Belgium The aim of Chapter 58 is to give a thorough overview of secure remote reconfiguration technologies for wireless embedded systems, and of the communication standard commonly used in those systems. In particular, authors focus on basic security mechanisms both at hardware and protocol level. We will discuss the possible threats and their corresponding impact level. Different countermeasures for avoiding these security issues are explained. Finally, the chapter presents a complete and compact solution for a service-oriented architecture enabling secure remote reconfiguration of wireless embedded systems, called the STRES system. Chapter 59 Secure Routing and Mobility in Future IP Networks.......................................................................... 952 Kaj Grahn, Arcada University of Applied Sciences, Finland Jonny Karlsson, Arcada University of Applied Sciences, Finland Göran Pulkkis, Arcada University of Applied Sciences, Finland The evolution of computer networking is moving from static wired networking towards wireless, mobile, infrastructureless, and ubiquitous networking. In next-generation computer networks, new mobility features such as, seamless roaming, vertical handover, and moving networks are introduced. Secu-
rity is a major challenge in developing mobile and infrastructureless networks. Specific security threats in next-generation networks are related to the wireless access mediums, routing, and mobility features. Chapter 59 identifies these threats, and discuss the state of the art of security research and standardization within the area, proposing security architectures for mobile networking. A survey of security in routing is provided with special focus on mobile ad hoc networks (MANETs). The security of currently relevant protocols for management or node and network mobility, Mobile IP (MIP), Network Mobility (NEMO), Mobile Internet Key Exchange (MOBIKE), Host Identity Protocol (HIP), Mobile Stream Control Transmission Protocol (mSCTP), Datagram Congestion Control Protocol (DCCP), and Session Initiation Protocol (SIP), is described. Section 6 Applications, Surveys and Case Studies Chapter 60 Evaluation of a Mobile Platform to Support Collaborative Learning: Case Study............................. 974 Carlos Quental, Polytechnic Institute of Viseu, Portugal Luis Gouveia, University Fernando Pessoa, Portugal In an educational context, technological applications and their supporting infrastructures have been evolved in a way that the use of learning objects is no longer limited to a personal computer, but has been extended to a number of mobile devices. Such evolution leads to the creation of a technological model called m-learning that offers great benefits to education. This educational model has been developed over the recent years, which resulted in several research projects and some commercial products. This chapter describes the (re)use of an adapted platform from an API of MLE (Mobile Learning Engine), to create tests, quizzes, forums, SMS, audio, video, mobile learning objects, in combination with a learning platform in a particular setting. MLE is a special m-learning application for mobile phones (a J2ME application) that can access a LMS (Learning Management System) and use most of its activities and resources, and add new, even innovative, activities. With J2ME one can store, use content and learn without the need of further network access and even use interactive questions that can be directly solved on mobile devices. The MLE enables one to use the mobile phone as a constant way of learning. As a consequence it is possible to use every spare time to learn, no matter where we are, providing new opportunities to enhance learning. Chapter 61 Power Issues and Energy Scavenging in Mobile Wireless Ad-Hoc and Sensor Networks................. 994 Gianluca Cornetta, Universidad San Pablo-CEU, Spain Abdellah Touhafi, Erasmushogheschool Brussel, Belgium David J. Santos, Universidad San Pablo-CEU, Spain José Manuel Vázquez, Universidad San Pablo-CEU, Spain Wireless ad-hoc and sensor networks are experiencing a widespread diffusion due to their flexibility and broad range of potential uses. Nowadays they are the underlying core technology of many industrial and remote sensing applications. Such networks rely on battery-operated nodes with a limited
lifetime. Although, in the last decade, a significant research effort has been carried out to improve the energy efficiency and the power consumption of the sensor nodes, new power sources have to be considered to improve node lifetime and to guarantee a high network reliability and availability. Energy scavenging is the process by which the energy derived from external sources is captured, translated into an electric charge and stored internally to a node. At the moment, these new power sources are not intended to replace the batteries, since they cannot generate enough energy; however, working together with the conventional power sources they can significantly improve node lifetime. Low-power operation is the result of a complex cross-layer optimization process, for this reason, this chapter thoroughly reviews all the traditional methods aimed at reducing power consumption at network, MAC and PHY levels of the TCP stack, to understand advantages and limitations of such techniques, and to justify the need of alternative power sources that may allow, in the future, the design of completely self-sustained and autonomous sensor nodes. Chapter 62 A Low Cost Wireless Sensors Network with Low-Complexity and Fast-Prototyping...................... 1021 João Carmo, University of Minho, Portugal José Correia, University of Minho, Portugal This chapter presents a low cost/fast prototyping wireless sensors network that was designed for a huge range of applications and making use of low cost commercial of the shelf components. Such applications includes industrial measurements, biomedical, domestic monitoring, remote sensing, among others. The concept of the wireless sensor network is presented and simultaneously, hot topics and their implementation are discussed. Such topics are valuable tools and can’t be discarded when a wireless sensors network is planed. By the contrary, such tools must be taken in account to make the communications between the nodes and the base station the best possible reliable. The architecture, protocols and the reasons that were behind the selection of the components are also discussed. The chapter also presents performance metrics that are related to with the physical characteristics of sensors and with the radio specificity. Microcontrollers with a RISC architecture are used by the network nodes to control the communication and the data acquisition and operate in the 433 MHz ISM band with ASK modulation. Also, in order to improve the communication and to minimise the lost of data, it is predicted to put the wireless nodes to handle line and source coding schemes. Chapter 63 Unreliable Failure Detectors for Mobile Ad-hoc Networks.............................................................. 1039 Luciana Arantes, University Paris 6, France Fabiola Greve, Federal University of Bahia, Brazil Pierre Sens, University Paris 6, France Failure detection is an important abstraction for the development of fault-tolerant middleware, such as group communication toolkits, replication and transaction services. Unreliable failure detector (namely, FD) can be seen as an oracle which provides information about process failures. The dynamics and self-organization of Mobile Ad-hoc Networks (MANETs) introduce new restrictions and challenges for the implementation of FDs with which static traditional networks do not have to cope. It is worth mentioning that in some way, fault tolerance is more critical for MANETs than for the latter, since wireless
network can present high error rates and mobile nodes are more prone to failures, physical damages or transient disconnections. The aim of this chapter is thus to discuss the impact of all these characteristics, intrinsic to MANET, in the implementation of FDs. It presents a survey of the few works about FD implementations for wireless networks, including the different possible assumptions to overcome the dynamics and lack of both global view and synchrony of MANETs. Chapter 64 Mission-Aware Adaptive Communication for Collaborative Mobile Entities................................... 1056 Jérôme Lacouture, Université de Toulouse, France Ismael Bouassida Rodriguez, Université de Toulouse, France Jean-Paul Arcangeli, Paul Sabatier University, France Christophe Chassot, Université de Toulouse, France Thierry Desprats, Paul Sabatier University, France Khalil Drira, Université de Toulouse, France Francisco Garijo, Université de Toulouse, France Victor Noel, Paul Sabatier University, France Michelle Sibilla, Paul Sabatier University, France Catherine Tessier, ONERA Centre de Toulouse – DCSD, France Adaptation of communication is needed to maintain the connectivity and quality of communication in group-wide collaborative activities. This becomes quite a challenge to handle when mobile entities are part of a wireless environment, in which responsiveness and availability of the communication system are required. In this chapter, these challenges are addressed within the context of the ROSACE project where mobile ground and flying robots have to collaborate either between themselves or with remote artificial and human actors during save and rescue missions in the event of disasters such as forest fires. This chapter presents the first results. The final goal is to propose new concepts, models and architectures that supports cooperative adaptation which is aware of the mission being executed. Thus, the communication system can be adequately adapted in response to predictable or unpredictable evolutions of the activity requirements and to the unpredictable changes in the communication resource constraints. Chapter 65 OntoHealth: An Ontology Applied to Pervasive Hospital Environments.......................................... 1077 Giovani Librelotto, Federal University of Santa Maria, Brazil Iara Augustin, Federal University of Santa Maria, Brazil Jonas Gassen, Federal University of Santa Maria, Brazil Guilherme Kurtz, Federal University of Santa Maria, Brazil Leandro Freitas, Federal University of Santa Maria, Brazil Ricardo Martini, Federal University of Santa Maria, Brazil Renato Azevedo, Federal University of Santa Maria, Brazil In the last years ontologies are being used in the development of pervasive computing applications. It is habitual their use for facilitating the interoperability among context-aware applications and the entities that may enter in the context at any time. This chapter presents OntoHealth: an ontology applied to health pervasive environment and a tool to its processing. The main idea is that a hospital could be
seen as this pervasive environment, where someone, through ubiquitous computing, engages a range of computational devices and systems simultaneously, in the course of ordinary activities, and may not necessarily even be aware that they are doing so. With the proposed ontology and the tool for its processing, the medical tasks can be shared by all components of this pervasive environment. Chapter 66 Adoption of Mobile and Information Technology in an Energy Utility in Brazil............................. 1091 Osvaldo Garcia, Pontificia Universidade Católica do PR, Brazil Maria Cunha, Pontificia Universidade Católica do PR, Brazil This chapter deals with the adoption of mobile technology. The case illustrated here is the implementation of mobile and wireless technology – MIT and smartphones – at an energy utility. The objective was to understand the human and social aspects of the adoption of this technology. This paper makes use of the metaphor of hospitality proposed by Ciborra in the late 1990s. The hospitality metaphor was a useful alternative for describing the process of adopting a new technology. It touches on technical aspects and notes human reactions that become evident when a technician comes across an unknown ‘guest’, the new technology: the doubtful character of the guest, the reinterpretation of the identities of guest and host during the process, learning through trial and error, the technology’s ‘drift’, the participants’ emotions and state of mind, and the appropriation of, and the care for, the new technology. Chapter 67 Infrastructures for Development of Context-Aware Mobile Applications......................................... 1104 Hugo Feitosa de Figueirêdo, University of Campina Grande, Brazil Tiago Eduardo da Silva, University of Campina Grande, Brazil Anselmo Cardoso de Paiva, University of Maranhão, Brazil José Eustáquio Rangel de Queiroz, University of Campina Grande, Brazil Cláudio De Souza Baptista, University of Campina Grande, Brazil Context-aware mobile applications are becoming popular, as a consequence of the technological advances in mobile devices, sensors and wireless networking. Nevertheless, developing a context-aware system involves several challenges. For example, what will be the contextual information, how to represent, acquire and process this information and how it will be used by the system. Some frameworks and middleware have been proposed in the literature to help programmers to overcome these challenges. Most of the proposed solutions, however, neither have an extensible ontology-based context model nor uses a communication method that allows a better use of the potentialities of the models of this kind. Chapter 68 A Practice Perspective on Transforming Mobile Work..................................................................... 1119 Riikka Vuokko, Åbo Akademi University, Finland Chapter 68 introduces a study that explores users’ experiences during an organizational implementation of a new mobile information technology in public home care environment. The home care case illus-
trates differences between implementation project goals and expectations, and on the other hand, the daily organizing and carrying out care work, where previously, no information technology was utilized. While implementing mobile technology was expected to enhance the efficiency of care working, the project outcomes include resistance due to surveillance aspect of the new technology as well as technological problems during the implementation. Successful outcomes of the implementation include better planning of working hours and more even distribution of work resources. Chapter 69 Data Replication Support for Collaboration in Mobile and Ubiquitous Computing Environments.......... 1132 João Barreto, INESC-ID/Technical University Lisbon, Portugal Paulo Ferreira, INESC-ID/Technical University Lisbon, Portugal In Chapter 69, the authors address techniques to improve the productivity of collaborative users by supporting highly available data sharing in poorly connected environments such as ubiquitous and mobile computing environments. Authors focus on optimistic replication, a well known technique to attain such a goal. However, the poor connectivity of such environments and the resource limitations of the equipments used are crucial obstacles to useful and effective optimistic replication. The authors analyze state-of-the art solutions, discussing their strengths and weaknesses along three main effectiveness dimensions: (i) faster strong consistency, (ii) with less aborted work, while (iii) minimizing both the amount of data exchanged between and stored at replicas; and identify open research issues Chapter 70 Providing Outdoor and Indoor Ubiquity with WLANs..................................................................... 1155 Diana Bri, Polytechnic University of Valencia, Spain Hugo Coll, Polytechnic University of Valencia, Spain Sandra Sendra, Polytechnic University of Valencia, Spain Jaime Lloret, Polytechnic University of Valencia, Spain Wireless Local Area Networks are very useful for the most applications based on network. It can be developed in almost all environments and products are cheap and robust. Moreover, these networks can be formed by different devices with wireless interfaces like IP cameras, laptops, PDAs, sensors, etc. WLANs provide high bandwidth at large coverage areas, which it is necessary in many applications at different research areas. All these characteristics let WLANs be a useful technology to provide ubiquity for any type of service. If they are deployed from a good and exhaustive design, they can provide connection to any device, everywhere at anytime. In this paper we present a complete guideline about how to design and deploy WLANs and to get their best performance. Authors start from an analytical point of view and use mathematical expressions to design WLANs in both indoor and outdoor environments. Then, the authors introduce a method proposed by some authors of this chapter some years ago and how it can be used to design WLANs in indoor environments. The chapter also presents WLANs design in outdoor environments and describe two projects developed in order to provide ubiquity in real indoor and outdoor environments.
Chapter 71 INTIC for Mobile Devices: Support System for Communication with Mobile Devices for the Disabled.................................................................................................................................. 1169 Cristina Diaz Busch, University of A Coruna, Spain Alberto Moreiras Lorenzo, University of A Coruna, Spain Iván Mourelos Sánchez, University of A Coruna, Spain Betania Groba González, University of A Coruna, Spain Thais Pousada García, University of A Coruna, Spain Laura Nieto Riveiro, University of A Coruna, Spain Javier Pereira Loureiro, University of A Coruna, Spain The In-TIC system for mobile devices (in Spanish: Integration with Information and Communication Technologies system for mobile devices) represents an approach towards the area of technical aids for mobile devices. The mobile telephone is a device that makes our lives easier, allowing us to be permanently accessible and in contact, to save relevant information, and also for entertainment purposes. However, people with visual, auditory or motor impairment or the elderly still find these devices difficult to use. They have to overcome a range of difficulties when using mobile telephones: the screens are difficult to read, the buttons are too small to use, and the technical features are too complicated to understand. At present, the main advances in mobile technology have been aimed at improving multimedia-messaging services and reproducing videos and music. This new support system adds accessibility to mobile telephones, making them easier to use for the people who need them the most, people with reduced physical or mental capacities who cannot use a conventional mobile. Chapter 72 New Ways to Buy and Sell: An Information Management Web System for the Commercialization of Agricultural Products from Family Farms without Intermediaries................ 1182 Carlos Ferrás, University of Santiago Compostela, Spain Yolanda García, University of Santiago Compostela, Spain Mariña Pose, University of Santiago Compostela, Spain Granxafamiliar.com is a project for developing the Galician rural milieu both socio-economically and culturally in order to appreciate the quality of life and rural culture, to create communication links between the rural and urban world, to emphasize the importance of the traditional self-supply production market of Galician family farms, and to promote the spread of new technologies as a social intervention tool against the phenomenon of social and territorial exclusion known as the “Digital Divide”. The authors are planning the architecture of www.granxafamiliar.com, which is developing the creation of a virtual community based on boosting commercial transactions and the possibilities for buying and selling traditional self-supply products that exist in the rural environment. The authors expect to promote it globally across the Internet by promoting the use and spread of ICTs as tools and commercial channels for agricultural products and intend to carry out an in-depth empirical and theoretical study of the territorial and social effects linked to the development of the information and communication society in rural communities. Their aim is to assist the progress of public decision-making and administrative efficiency for when the time comes to invest in suitable services and activities related to the information society in the rural environment.
Chapter 73 Broadcast Quality Video Contribution in Mobility........................................................................... 1199 José Ramón Cerquides Bueno, University of Seville, Spain Antonio Foncubierta Rodriguez, University of Seville, Spain The continuous growth of the available throughput, especially in the uplink of mobile phone networks is opening the doors to new services and business opportunities without references in the past. In more concrete, new standards HSDPA/HSUPA, introduced to complement and enhance 3G networks, together with the advances in audio and especially video coding, like those adopted by the standard H.264 AVC have boosted the appearance of a new service: exploiting the mobile telephony networks for contributing broadcast quality videos. This new service is offering just now a low cost, high flexibility alternative that, in a brief period of time, will substitute the current Electronic News Gathering (ENG) Units, giving rise to what is being to be called Wireless Journalism (WENG or WiNG). This chapter discusses both the technologies involved and the business opportunities offered by this sector. Once reviewed the state of the art, different solutions will be compared, some of them recently appeared as commercial solutions, like QuickLink 3.5G Live Encoder or AirNow! and others still in research and development processes. Chapter 74 Mobile Device Selection in Higher Education: iPhone vs. iPod Touch............................................ 1213 C. Brad Crisp, Abilene Christian University, USA Michael Williams, Pepperdine University, USA Mobile devices are rapidly becoming the most common interface for accessing network resources (Hall 2008). By 2015 the average 18-year old will spend the majority of their computing time on mobile devices (Basso 2009). These trends directly affect institutions of higher learning. Many universities are offering learning initiatives and m-services designed to distribute content and services to mobile devices. Chapter 74 reports findings from an exploratory, longitudinal study at Abilene Christian University, where incoming freshmen received their choice of an Apple iPhone or iPod touch. The findings indicate that users’ device selections were affected by their perceptions of the costs of the devices, the devices’ relative characteristics, and the social influence of parents. We also found that users’ attitude, satisfaction, and confidence about their device selection varied across devices, with iPhone users having more favorable perceptions. The chapter concludes with recommendations for mobile learning initiatives and directions for future research. Chapter 75 Design of Wearable Computing Systems for Future Industrial Environments.................................. 1226 Pierre Kirisci, Bremer Institut für Produktion und Logistik GmbH, Germany Ernesto Morales Kluge, Bremer Institut für Produktion und Logistik GmbH, Germany Emanuel Angelescu, Bremer Institut für Produktion und Logistik GmbH, Germany Klaus-Dieter Thoben, Bremer Institut für Produktion und Logistik GmbH, Germany This chapter investigates the role of context, particularly in future industrial environments, and elaborates how context can be incorporated in a design method in order to support the design process of
wearable computing systems. The chapter is initiated by an overview of basic research in the area of context-aware mobile computing. The aim is to identify the main context elements which have an impact upon the technical properties of a wearable computing system. Therefore the authors describe a systematic and quantitative study of the advantages of context recognition, specifically task tracking, for a wearable maintenance assistance system. Based upon the experiences from this study, a context reference model is proposed, which can be considered supportive for the design of wearable computing systems in industrial settings, thus goes beyond existing context models, e.g. for context-aware mobile computing. The final part of this chapter discusses the benefits of applying model-based approaches during the early design stages of wearable computing systems. Existing design methods in the area of wearable computing are critically examined and their shortcomings highlighted. Based upon the context reference model, a design approach is proposed through the realization of a model-driven software tool which supports the design process of a wearable computing system while taking advantage of concise experience manifested in a well-defined context model. Chapter 76 Extending the Scope of eID Technology: Threats and Opportunities in a Commercial Setting........ 1246 Vincent Naessens, Katholieke Hogeschool Sint-Lieven, Belgium Bart De Decker, Katholieke Universiteit Leuven, Belgium In 2002, Belgium has adopted an electronic identity card as one of the first countries in Europe. By the end of 2009, the roll-out of the eID card will be completed, and this means that each Belgian citizen will possess an eID card. The card enables her to digitally prove her identity and to legally sign electronic documents. The Belgian eID card opens up new opportunities for the government, its citizens, service providers and application developers. The Belgian eID technology originally aimed at facilitating transactions between Belgian citizens and the government and although many eID applications have been developed, the success of the Belgian eID technology has not been what was expected. Therefore, the Belgian government encourages developers to build commercial applications that use the eID card (for authentication or e-signatures). However, extending the scope of the Belgian eID technology from egovernment to the commercial sector is no sinecure and not without risks. Chapter 77 Mobility and Connectivity: On the Character of Mobile Information Work..................................... 1262 Victor Gonzalez, University of Manchester, UK Antonis Demetriou, University of Manchester, UK Mobile information work, an extreme type of information work, is progressively becoming commonplace in various corporations. The availability of cheap and portable information technologies as well as the development of pervasive communication infrastructure in some parts of the world is creating scenarios where people can work from almost anyplace. Nevertheless up to now there has not been sufficient research on the particular work practices and strategies these professional workers use to be productive as they face the particular challenges of being mobile. Based on an ethnographic investigation of the experiences of mobile professional workers in a multi-national accountancy company, this chapter discusses some characteristics defining the character of modern information work with regards
mobility and connectivity while operating outside the workplace. The study highlights the importance of: location in terms of providing an adequate atmosphere and infrastructure to conduct work; regularity in terms of giving workers flexibility to connect and reconnect whenever it was more convenient for them; space in terms of letting people preserve and reconstruct their information workspaces; and balance while juggling between personal and work related commitments. The findings presented can be useful for defining the processes and technological tools supporting mobile professional workers.
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Foreword
Mobility has become the next big challenge in our inter-connected world. Indeed, after the Internet widespread dissemination, users are eager for information anytime anywhere. Although ubiquity brought the power of computing anywhere, it is the access to global information that enriches the usefulness of mobile computing. From an historical perspective, the Internet widespread dissemination enabled the access to huge amounts of free information. This information is accessible from any pc, provided it is connected to a network. Naturally, the users that were previously restricted to a desktop pc now aspire to have the same access to information from everywhere. Acessing information anytime, everywhere requires a mobile computing environment. To the development of a mobile computing environment contributed the miniaturization of devices and the improvement on wireless technologies. From the miniaturization of devices spurred Smartphones, devices that merge the mobile phone with the pocket pc concepts, and Netbooks, small laptops that favor (wireless) communications to raw computing power. On the other hand, the development of carrier technologies with increased network bandwidth popularized broadband access either at home (through cable) or on mobile devices (through wireless). We now live in a highly inter-connected world, made of several networks, available from a multitude of wireless technologies that enable a mobile behavior (consider for example WiFi, WiMAX, UMTS, HSDPA).
CHALLENGES AND OPPORTUNITIES AVAILABLE However, (hardware) technology by itself does not suffice to harness the challenges present on a mobile computing environment. It is necessary to consider how technology should be used by applications. The applications for the mobile environment share the same communication model but also the same limitations found in Internet applications. There is an overwhelming range of distributed applications available for distributed systems in general, and for the Internet in particular, that can be brought to the mobile environment. However, the mobile environment presents some specific challenges that are not common for a generic distributed system like the Internet. Device and service availability is an important property of a mobile system since some devices may come and go from the system, rather than being permanently available like the typical server device. A consequence of the absence of permanent availability is the absence of data persistency. Where should
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data be stored? After storing data, possibly in more than a single place, synchronization is another important property. Is the data being accessed the most up-to-date? When looking at the Web evolution, it is possible to clearly identify two phases: the first is about accessing information; and the second is about accessing (web) services. Like the Web, the mobile environment is perfectly capable of offering remote services. Joining services with mobility opens up new market opportunities. For example, geographic based advertising is an example of merging information access (through web services) and mobile positioning. Several web-based map providers are starting to offer recommendations based on the location of the user. This can only be possible having a mobile device that can communicate through a wireless network. Nowadays, there are a variety of (mobile) devices and applications that are capable of running mobile services (consider for example a Smartphone with email/internet access and GPS positioning). Yet, little is known of the success of this new technology, and most importantly, how are people adopting it. The success of a mobile platform is not determined exclusively by technology, but also by how people use it to enrich their lives.
CONTRIBUTIONS OF THE BOOK This handbook of research contributes with state-of-the-art research on all three aspects considered previously: technology, applications and social impact on the adoption of these systems. Several technologies are covered in the book, ranging from performance improvements and routing optimizations on (generic) wireless networks; considerations for WiMAX; new designs for sensor networks; and new uses for RFID and Near Field Communication systems. In the application arena, several areas of interest have been covered, namely: health, e-government, advertisement, e-learning, university campus services, vehicular networks, Virtual and Small-Medium Enterprises and mobile grid computing. A particular attention was given to e-learning, with several contributions in providing lessons through mobile devices, supporting and monitoring tools on mobile devices and identifying success factors for mobile learning model, including specific case studies in large organizations. Device localization received several contributions for being an important operational feature for positioning mobile devices. Two wide range of localization schemes were considered: GPS based and local wireless (WiFi) based. Device localization is necessary to enhance a whole range of services, from advertisement to social ones. Vehicular networks are yet another mobile computing platform that has specific characteristics as a wireless ad-hoc network. This type of network raises unique challenges and security issues that were identified and are not present on typical (computer) networks. In the social impact of a mobile computing platform, several domains have been presented, from a specific collaborative learning environment, to the use of mobile devices in higher education institutions to enterprise institutions. Indeed, the adoption of mobile devices is a disruption of the typical stationary computing platform. Youngsters tend to adopt more easily new technologies, in this case mobile devices, than elders. The typical population of education institutions is younger than enterprise institutions, hence the interest of these case studies in different environments. However, the mobile platform is not confined to the educational environment, and hence the interest of considering how mobile applications can be applied to
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new domains like tourism and entertainment. Regardless of the specific domain in use, it is shown the viability of business models for mobile e-commerce. In summary, a handbook of research that demonstrates what can be achieved within this domain would have been welcome in itself. A handbook that besides this purpose gives real insight, and that drives and inspires those that read it to contribute to the ongoing technological improvements and development of successful applications, represents a major contribution to the body of knowledge in mobility and computing.
Nuno Lopes Assistant Professor of Networks and Communication Technologies Polytechnic Institute of Cávado e Ave Portugal Nuno Lopes received his Bachelor (5 year degree) in Systems and Informatics Engineering, in 2002, from University of Minho, Braga, Portugal. During this course, he made an internship at Philips Research, Eindhoven, The Netherlands. Later on he received his PhD degree in Computer Science, from University of Minho, Portugal, in 2009. His PhD focused on the building of large-scale indexing systems through the use of structured peer-to-peer networks. He is currently an Assistant Professor at the Instituto Politécnico do Cávado e do Ave, Barcelos, Portugal, teaching Network Communications and Operating Systems courses, among others. His research interests include Distributed Systems, Decentralized Algorithms, Peer-to-peer Networks, and Large-scale Information Retrieval.
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Preface
ABOUT THE SUBJECT The advances in mobile and ubiquitous technologies have more than 35 years of research. After all these years the ubiquity vision is becoming a reality, due to the evolution and new features of the hardware and software components. The advent of Web services and the progress on wearable devices, ambient components, user-generated content, mobile communications, and many other gave origin to new applications and services. Recently advances in web services technologies allowed the integration into mobility. With these two components appeared new business models which imply improvements in technical infrastructure that enables the progress of mobile services and applications. These include dynamic and on-demand service, context-aware services, and mobile web services. While driving new business models and new online services, particular techniques must be developed for web service composition, web service-driven system design methodology, creation of web services, and on-demand web services. The technological, social and organizational dimensions of mobile and ubiquitous computing will be supported by new educational paradigm. Two trends converge to make this possible; increasingly powerful cell phones and PDAs, and improved access to wireless broadband. This handbook of research represents a collection of the most recent developments on the technological, organizational and social dimensions of this highly potential technology of mobility and computing, that dictate a paradigm shift in organizations, society and people. It covers the following dimensions: • •
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The technological dimension, addressing emerging technologies such as Wireless data communication networks; Mobile technologies; Standards and reference models; and Security. The organizational, human and social perspectives, comprising: New business models; Collaborative work; Learning and teaching; Social networks; Studies on adoption; Studies of impact; Critical success factors; and level of preparedness of organizations and people. Applications and solutions developed or under development, and research and development results that address a broad range of sectors, from business to government services, from education to e-Health. The chapters included in the handbook,
•
discuss the importance of this technologies and their support to new applications and solutions, namely in sectors of activity such as business, new organizational and ubiquitous models, eCommerce, government, e-Health, e-Learning, etc.;
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• • • • • •
present practical solutions and recent developments; introduce the state-of-the-art technologies; discuss organizational preparedness for new organizational models potentiated by ubiquity and mobility; discuss the impact on society and on people; discuss critical success factors; introduce future generations of communications and networks.
ORGANIZATION OF THE HANDBOOK This handbook is a compilation of 77 contributions to the discussion of the main issues, challenges, opportunities and developments related with mobility and computing, in a very comprehensive way, in order to disseminate current achievements and practical solutions and applications. These 77 chapters are written by a group of near 240 authors that include many internationally renowned and experienced researchers and specialists in the e-Business field and a set of younger authors, showing a promising potential for research and development. Contributions came from the five continents, and are included contributions from academia, research institutions and industry, representing a good and comprehensive representation of the state-of-the-art approaches and developments that address the several dimensions of this fast evolutionary thematic. The “Handbook of Research on Mobility and Computing: Evolving Technologies and Ubiquitous Impacts” is organized in six sections: Section 1: Mobile Technologies Section 2: Emerging Technologies Section 3: Critical Success Factors Section 4: New Business Models Section 5: Security Section 6: Applications, Surveys and Case Studies The first section, Mobile Technologies is composed by 36 chapters that address relevant research and development contributions to the field of mobility and computing, summarized below. Chapter one, Evaluating the Context Aware Browser: A Benchmark for Proactive, Mobile, and Contextual Web Search, discusses the evaluation of highly interactive and novel context-aware system with a methodology based on a TREC-like benchmark. The authors take as a case study an application for Web content perusal by means of context-aware mobile devices, named Context-Aware Browser. In this application, starting from the representation of the user's current context, queries are automatically constructed and used to retrieve the most relevant Web contents. Since several alternatives for query construction exist, it is important to compare their effectiveness, and to this aim we developed a TREClike benchmark. The authors present their approach to an early stage evaluation, describing their aims and the techniques applied, underlining for, for the evaluation of context-aware retrieval systems, the benchmark methodology adopted could be an extensible and reliable tool. Routing is the process of finding a path from a source node to a destination node. Proposed routing schemes can be divided into topological and position based, depending on the availability of geographic
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location for nodes. Topological routing may be proactive or reactive, while position based routing consists of greedy approaches applied when a neighbor closer to the destination (than the node currently holding the packet) exists, and recovery schemes otherwise. In order to preserve bandwidth and power which are critical resources in ad hoc and sensor networks, localized approaches are proposed, where each node acts based solely on the location of itself, its neighbors, and the destination. There are various measures of optimality which lead to various schemes which optimize hop count, power, network lifetime, delay, or other metrics. This second chapter, Routing in Wireless Ad Hoc and Sensor Networks, describes a uniform solution based on ratio of cost and progress. Mobile communication networks have become an integral part of our society, significantly enhancing communication capabilities. Mobile ad hoc networks (MANETs) extend this capability to any time/ anywhere communication, providing connectivity without the need of an underlying infrastructure. Chapter three, Mobile Ad Hoc Networks: Protocol Design and Implementation investigates the new coming realm of mobile ad hoc networks, focusing on research problems related to the design and development of routing protocols, both from a formal and technical point of view. Then the link stability in a high mobility environment is examined, and a route discovery mechanism is analyzed, together with a practical implementation of a routing protocol in ad hoc multi-rate environments which privileges link stability instead of traditional speed and minimum distance approaches. The convergence of wireless applications presents a greater hope for consolidating e-Government applications even in resource-constrained countries such as those in Africa. Chapter four, Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa, presents an exploratory study that aims at discussing the extent as to how convergence of wireless technologies from different vendors promises to contribute to the consolidation of e-Government applications in SubSaharan-Africa (SSA). This is done by reviewing the different adoption stages of ICT and e-Government in SSA. It looks at challenges facing adoption of wireless technologies (GSMs, Wireless Internet Access, satellite transmission, etc.) across all the socio-economic value chains in SSA. The chapter looks at Botswana and South Africa as case studies by bringing out the different interventions that have been done in the realm of facilitating a conducive environment for the convergence of different wireless technologies. Out of the analysis of legal, regulatory, market and spectrum policies affecting the adoption of wireless communications in SSAs, the chapter draws out recommendations on how to consolidate wireless communications to be adopted in different socio-economic setups (e.g. e-government, e-Health, e-Banking, etc.). The fifth chapter, Process Innovation with Ambient Intelligence (AmI) Technologies: A Comparison of Australian and German Small and Medium Enterprise (SME) Manufacturers, considers the potential for absorptive capacity limitations to prevent SME manufacturers benefiting from the implementation of Ambient Intelligence (AmI) technologies. The chapter also examines the role of intermediary organisations in alleviating these absorptive capacity constraints. In order to understand the context of the research, a review of the role of SMEs in the Australian manufacturing industry, plus the impacts of government innovation policy and absorptive capacity constraints in SMEs in Australia is provided. Advances in the development of ICT industry standards, and the proliferation of software and support for the Windows/ Intel platform have brought technology to SMEs without the need for bespoke development. The results from the joint European and Australian AmI-4-SME projects suggest that SMEs can successfully use "external research sub-units" in the form of industry networks, research organisations and technology providers to offset internal absorptive capacity limitations.
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Chapter six, Providing Ubiquitous Access to Synthetic Sign Language Contents Over Multiple Platforms, presents the design of distributed sign language synthesis architecture. The main objective of this design is to adapt the synthesis process to the diversity of user devices. The synthesis process has been divided into several independent modules that can be run either in a dedicated server or in the client device. Depending on the modules assigned to the server or to the client, four different scenarios have been defined. These scenarios may vary from a heavy client design which executes the whole synthesis process, to a light client design similar to a video player. These four scenarios will provide equivalent signed message quality independently of the device’s hardware and software resources. Chapter seven, The Impact of MIMO Communication on Non-Frequency Selective Channels Performance, reviews the basic concepts of multiple-input multiple-output (MIMO) communication systems and analyses their performance within non-frequency selective channels. The MIMO system model is established and by applying the singular value decomposition (SVD) to the channel matrix, the whole MIMO system can be transformed into multiple single-input single-output (SISO) channels having unequal gains. In order to analyze the system performance, the quality criteria needed to calculate the error probability of M-ary QAM (Quadrature Amplitude Modulation) are briefly reviewed and used as reference to measure the improvements when applying different signal processing techniques. Bit and power allocation is a well-known technique that allows improvement in the bit-error rate (BER) by managing appropriately the different properties of the multiple SISO channels. It can be used to balance the BER’s in the multiple SISO channels when minimizing the overall BER. In order to compare the various results, the efficiency of fixed transmission modes is studied in this work regardless of the channel quality. It is demonstrated that only an appropriate number of MIMO layers should be activated when minimizing the overall BER under the constraints of a given fixed date rate. Chapter eight, Node Localization in Ad-hoc Networks, introduces node localization techniques in adhoc networks including received signal strength (RSS), time-of-arrival (TOA) and direction-of-arrival (DOA). Wireless channels in ad-hoc networks can be categorized as LOS and NLOS. In LOS channels, the majority of localization techniques perform properly. However, in NLOS channels, the performance of these techniques reduces. Therefore, non-line-of-sight (NLOS) identification and mitigation techniques, and localization techniques for NLOS scenarios are briefly reviewed. The technological revolution that has created a vast health problem due to a drastic change in lifestyle also holds great potential for individuals to take better care of their own health. This is the focus of the presented overview of current applications, and prospects for future research and innovations, addressed by chapter nine, Wireless and Mobile Technologies Improving Diabetes Self-Management. The presented overview and the main goals of the systems included are to utilize ICT as aids in self-management of individual health challenges, for the disease Diabetes, both for Type 1 and Type 2 diabetes. People with diabetes are generally as mobile as the rest of the population, and should have access to mobile technologies for managing their disease. Forty-seven relevant studies and prototypes of mobile, diabetesspecific self-management tools meeting our inclusion criteria have been identified; 27 publicly available products and services, nine relevant patent applications, and 31 examples of other disease-related mobile self-management systems are included to provide a broader overview of the state of the art. Finally, the reviewed systems are compared, and future research directions are suggested. Chapter ten, Adaptive Multicarrier Frequency Hopping Spread Spectrum Combined with Channel Coding, presents an adaptive Multicarrier Frequency Hopping Spread Spectrum (MCFH-SS) system employing proposed Quasi Cyclic Low Density Parity Check (QC-LDPC) codes instead of the conventional LDPC codes. A new technique for constructing the QC-LDPC codes based on row division method
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is proposed. The new codes offer more flexibility in terms of girth, code rates and codeword length. Moreover, a new scheme for channel prediction in MCFH-SS system is also proposed. The technique adaptively estimates the channel conditions and eliminates the need for the system to transmit a request message prior to transmitting the packet data. The proposed adaptive MCFH-SS system uses PN sequences to spread out frequency spectrum, reduce the power spectral density and minimize the jammer effects. Although B2B e-commerce provides healthcare organizations a wealth of new opportunities and ways of doing business, it also presents them with a series of challenges. B2B e-commerce adoption remain poorly understood and it is also a relatively under-researched area. Therefore, case studies were conducted to investigate the challenges and issues in adopting and utilizing B2B e-commerce systems in the healthcare sector. The major aims of the study presented in chapter eleven, Key Adoption Challenges and Issues of B2B E-Commerce in the Healthcare Sector are to: (a) identify and examine main B2B e-commerce adoption challenges and issues for healthcare organizations; and (b) develop a B2B e-commerce adoption challenges and issues table to assist healthcare organizations in identifying and managing them. Chapter twelve, A Pervasive Polling Secret-Sharing Based Access Control Protocol for Sensitive Information, presents a novel access control mechanism for sensitive information which requires permission from different entities or persons to be accessed. The mechanism consists of a file structure and a protocol which extend the features of the OpenPGP Message Format standard by using secret sharing techniques. Several authors are allowed to work in the same file, while access is blocked for not authorized users. Access control rules can be set indicating the minimum number of authors that need to be gathered together in order to open the file. Furthermore, these rules can be different for each section of the document, allowing collaborative work. Non-repudiation and authentication are achieved by means of a shared signature. The scheme’s features are best appreciated when using it in a mobile scenario. Deployment in such an environment is easy and straight. Mobile devices, including cell phones, capable of geo-positioning (or localization) are paving the way for new computer assisted systems called mobile location-based recommenders (MLBRs). MLBRs are systems that combine information on user’s location with information about user’s interests and requests to provide recommendations that are based on “location”. MLBR applications are numerous and emerging. One MLBR application is in advertisement where stores announce their coupons and users try to find the coupons of their interests nearby their locations through their cell phones. Chapter thirteen, Mobile Location-Based Recommenders: An Advertisement Case Study discusses the concept and characteristics of MLBRs and presents the architecture and components of a MLBR for advertisement. Mobile devices have become a new platform with many possibilities to develop studies and implement projects. The power and current capabilities of these devices besides its market penetration makes applications and services in the area of mobility particularly interesting. Mobile terminals have become small computers, they have an operating system, storage capacity so it is possible to develop applications that run on them. Today these applications are highly valued by users. Nowadays we want not only to talk or send messages by mobile terminal, but also to play games, to buy cinema tickets, to read email… We can bring these capabilities in our pocket. The University may not be aware of this fact. The students, due to their age, are the main users and purchasers. In this sense, chapter 14, Services for Mobile Devices in a Universitary Scenario, presents three applications developed for mobile devices, that are being used in Universidad Pontificia de Salamanca. All of them work on a university scenario and use different kind of services.
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Wireless Sensor Networks (WSNs) have experienced an amazing evolution during the last decade. Compared with other wired or wireless networks, wireless sensor networks extend the range of data collection and make it possible for us to get information from every corner of the world. The chapter begins with an introduction to WSNs and their applications. Chapter 15, Event Detection in Wireless Sensor Networks recognizes event detection as a key component for WSN applications. The chapter provides a structured and comprehensive overview of various techniques used for event detection in WSNs. Existing event detection techniques have been grouped into threshold based and pattern based mechanisms. For each category of event detection mechanism, the chapter surveys some representative technical schemes. The chapter also provides some analyses on the relative strengths and weaknesses of these technical schemes. Towards the end, the trends in the research regarding the event detection in WSNs are described. At the beginning of the 21st century in a world dominated by technology it is essential to enhance and update the school, creating conditions for the students to succeed, consolidating the role of ICT as a key resource for learning and teaching in this new era. In Chapter 16, M-English – Podcast: A Tool for Mobile Devices, the authors describe a study that was carried out in a Portuguese school. As a means to overcome some of the existing logistical obstacles in the school, where the possibility of carrying out ICT activities without restrictions was still dreamlike, the podcast was implemented as an m-learning tool. Being aware of the fact that nowadays mobile phones and mp3 players are part of our students’ lives, the authors took advantage of this fact and the podcast was used as a tool to support, to enhance and to motivate students to learn English, used thus as a complement to traditional (face-to-face) learning. Disaster can be defined as the onset of an extreme event causing profound damage or loss as perceived by the afflicted people. The networks built in order to detect and handle these events are called Public safety networks (PSNs). These networks have the fundamental role of providing communication and coordination for emergency operations. Many of the problems of the PSN field come from the heterogeneity of systems and agencies involved in the crisis site and from their mobility at the disaster site. The main aim of Chapter 17, Public Safety Networks, is to provide a broad view of the PSN field, presenting the different emergency management phases, PSNs requirements, technologies and some of the future research directions for this field. The purpose of Chapter 18, Mobile Applications as Mobile Learning and Performance Support Tools in Psychotherapy Activitites, is the analysis of mobile applications as performance and informal learning support tools that facilitate the development of the psychotherapy process. The “e-therapy” has become a common term to refer the delivery of mental health services, on-line or related to a computer mediated communication between a psychotherapist and the patient. Initially, a background on e-therapy is provided and after the “self-help therapy”–a kind of e-therapy where the concept of patient empowerment is important– is exposed. Then, the integration of mobile devices in the psychotherapy process will be explained considering how their technological features support patient therapeutic activities like behavior assessment and informal mobile learning. The relation of the mobile devices with psychotherapist work activities such as evidence gathering and patient monitoring will also be explained. The chapter includes a discussion on the mobile learning practices as a source of potential strategies that can be applied in the therapeutic field and finally a set of recommendations and future directions are described to explore new lines of research. Location-based services (LBSs) are impacting different aspects of human’s life. To date, different LBSs have been emerged, each supporting a specific application or service. While some LBSs have aimed at addressing the needs of general populations, such as navigation systems, others have been focused
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on addressing the needs of specific populations, including kids, youths, elderly, and people with special needs. In recent years, interest in taking a LBS approach in education and learning has grown. The main purpose of such educational LBSs is facilitating a means for learners to be more efficient and effective in their learning activities using their location as the underlying information in decision making. In CampusLocator: A Mobile Location-Based Service for Learning Resources the authors present a novel LBS, called CampusLocator, whose main goal is to assist students in locating and accessing learning resources including libraries, seminars, and tutorials that are available on a campus. WiMAX is being promoted as a potential solution to a number of problems that have plagued the wired and wireless broadband industry since it originated. Can WiMAX fulfill this promise in a crowded and competitive market? If so, what factors are critical to its success? Who will use WiMAX and for what purposes? This chapter, The Future of WiMAX, identifies both the critical success factors that will give WiMAX an edge over other existing wireless technologies and the key applications that will contribute to its success. The top three critical success factors for WiMAX are availability of handset devices and consumer premise equipment, bandwidth speed, and interoperability and standardization. A panel of WiMAX experts concludes that broadband on demand, wireless services provider access, and Voice over IP are the top three killer applications for WiMAX. Chapter 21, Determinants of Loyalty Intention in Portuguese Mobile Market, conceptualizes and highlights the determinants of customers’ loyalty in the Portuguese mobile market. The authors raise questions about the interrelationships of the cost and values dimensions and the consequences of these relationships on customer satisfaction and trust and consequently loyalty among different operators, addressing some recent models. By organizing and synthesizing the major research streams and tests empirically a conceptual framework through a SEM, with data gather in a survey of Portuguese clients, the present study advances knowledge on the nature of the relative importance of different components of loyalty to mobile communications operators. Some useful preliminary insights were produced related to customers’ retention process in primary mobile operator, which appears strongly related to price/ quality, followed by the emotional connection to the operator staff and others clients. Nonetheless, a considerable number of issues were left for future research, including the possibility of extending the investigation to other countries. Current technological advances and the increasing diffusion of its use for scientific, financial and social activities, make Internet the de facto platform for providing worldwide distributed data storage, distributed computing and communication. It creates new opportunities for the development of new kinds of applications, but it will also create several challenges in managing the information distributed on the Internet and in guaranteeing its “on-time” access through the network infrastructures that realize the Internet. Many researchers believed and still believe that the mobile agents could propose several attractive solutions to deal with such challenges and problems. Chapter 22, Mobile Agents: Concepts and Technologies, presents the core concepts of mobile agents, and attempts to provide a clear idea of the possibility of their use by introducing the problems they cope with, the application areas where they provide advantages with respect to other technologies and the available mobile agent technologies. Traditional networks suppose the existence of some path between endpoints, small end to end roundtrip Delay time, and loss ratio. Today, however, new applications, environments and types of devices are challenging these assumptions. In Delay Tolerant Networks (DTNs), an end-to-end path from source to destination may not exist. Nodes may connect and exchange information in an opportunistic way. Chapter 23, Vehicular Delay Tolerant Networks, presents a broad overview of DTNs, particularly focusing on Vehicular DTNs, their main characteristics, challenges, and research projects on this field. In the near
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future, cars are expected to be equipped with devices that will allow them to communicate wirelessly. However, there will be strict restrictions to the duration of their connections with other vehicles, whereas the conditions of their links will greatly vary; DTNs present an attractive solution. Therefore, VDTNs constitute an attractive research field. It has been substantially proven that the use of new technologies can improve a child's learning process. However, the main problem for the teacher continues to be that he/she cannot pay attention to all children at the same time. Sometimes it is necessary to decide which child must be first attended to. It is in this context that we believe our system has the ability to greatly help teachers: we have developed a learning process control system that allows teachers to determine which students have problems, how many times a child has failed, which activities they are working on and other such useful information, in order to decide how to distribute his/her time. Furthermore, bearing in mind the attention required by kindergarten students, Chapter 24, Monitoring the Learning Process through the use of Mobile Devices, proposes the provision of mobile devices (PDA - Personal Digital Assistant) for teachers, permitting free movement in the classroom and allowing the teacher to continue to help children while information about other students is being received. Therefore if a new problem arises the teacher is immediately notified and can act accordingly. Computer technologies, especially ICT have become ubiquitous in people’s lives. Nowadays, mobile phones, PDAs, laptops and a constellation of software tools are more and more used for a variety of activities carried out in both personal and professional lives. Given the features that these technologies provide and are provided with, for example, connectivity and portability, it can be said that ICTs have the potential to support nomadic work practices which are seen as increasingly characteristic of the knowledge economy. Chapter 25, The Making of Nomadic Work: Understanding the Mediational Role of ICTs, presents a review of the concept of nomadic work and, based on a broad literature analysis, discusses the ways in which ICTs may empower people who are involved with nomadic work practices. It aims to give a starting point for those who intend to develop further research on technologically-mediated nomadic work practices in the knowledge economy. Chapter 26, I-GATE: Interperception - Get All The Environments, introduces the I-GATE architecture, a new approach, which includes a set of rules and software architecture, to connect users from different interfaces and devices in the same virtual environment, transparently, even with low capacity of resources. The system detects the user resources and provides transformations on the data in order for its visualization in 3D, 2D and textual-only (1D) interfaces. This allows users from any interface to get a connection in the system using any device and to access and exchange information with other users (including ones with other interface types) in a straightforward way, without need to changing hardware or software. The authors formalize the problem, including modeling, implementation, and usage of the system, also introducing some applications that they have created and implemented in order to evaluate the proposal. Authors have used these applications in cell phones, PDAs, Digital Television, and heterogeneous computers, using the same architecture, with success. The widespread and availability of increasingly powerful mobile devices is contributing for the incorporation of new services and features on our daily communications and social relationships. In this context, geolocation of users and points of interest in mobile devices may contribute, in a natural way, to support either the mediation of remote conversations as the promotion of face-to-face meetings between users, leveraging social networks. The CONNECTOR system is based on geolocation data (people, content and activities), enabling users to create and develop their personal relations with other members of the CONNECTOR social network. Users, maps, sharing features and multimedia content
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are actors in this social network allowing CONNECTOR to address the promotion of geolocated social networks driven by physical proximity and common interests among users. Chapter 27, CONNECTOR: A Geolocated Mobile Social Service, discusses the work undertaken for the conceptualization and development of the CONNECTOR system. Preliminary evaluation results along with usage contexts are also presented. The chapter concludes with a discussion about future developments in geolocation and personalization in mobile communication services. Nowadays, triple-play services are offered in both wireless and wired networks. The network convergence and the new services such as VoIP and IPTV are a reality. However, the future of these networks will have a different concept, the ubiquity. The solutions must be based on the structures and current environments to carry out those challenges in a correct way. In order to reach this ubiquity, the science community has to take into account that its implementation should not assume a high cost to the user and that the system must comply with the quality of service measurements to satisfy the user. Chapter 28, Providing VoIP and IPTV Services in WLANs, introduces the main VoIP and IPTV (IP Television) transmission protocols and the compression formats most used as also the bandwidth needed. The goal is to provide ubiquity into multimedia scenarios in WLANs. Authors will carry out tests to guarantee the appropriate values in some network parameters such jitter, delay, number of lost packets and enough effective bandwidth that should be satisfied. They demonstrate the measurements taken from several test benches. They show the parameter values that the devices should perform in order to stay connected from anywhere at any time to these services. One of the sectors that have a great potential to use and exploit the new communication technologies is the healthcare sector. Nowadays, the application of all these new technologies to support the clinical procedures has taken part in the definition of a new concept known as e-Health. This concept involves a lot of different services related with the medicine/health terms and the information technologies. However, to provide emergency transportation with better care capabilities to the patient is something that still has a lot to improve. Within this context SIe-Health comes into being a software platform oriented for developing Telemedicine solutions. The solution model proposed in Chapter 29 SIe-Health, e-Health Information System, allows remote assistance for a mobile health emergency, integrating in this service electro-medical devices and videoconference services. The popularity of mobile computing creates new opportunities for information sharing and collaboration through technologies like radio frequency identification (RFID) tags and location awareness technologies. Chapter 30, Combining Location Tracking and RFID Tagging toward an Improved Research Infrastructure, discusses how these technologies, which provide subtly different information, can be used together toward increased benefit to users. This work introduces technologies for RFID and location awareness, including a survey of projects. The authors describe advantages of combining these technologies, illustrated through our system, TagIt, that uses these technologies in a traditional research poster environment to provide a rich multimedia experience and encourage ongoing feedback from poster viewers. An overview of TagIt is provided, including user commenting and information sharing capabilities that make use of RFID and location information. User feedback and an expert review highlights how TagIt could benefit authors, information consumers, and the research community, leading to future directions for the research community. The appearance of concepts such as “Ambient Intelligent”, “Ubiquitous Computing” and “ContextAwareness” is causing the development of a new type of services called “Context-Aware Services” that in turn may affect users of mobile communications. This technology revolution is a complex process because of the heterogeneity of contents, devices, objects, technologies, resources and users that can be
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coexist at the same local environment. The novel approach in Chapter 31, Model and Infrastructure for Communications in Context-Aware Services, is the development of a ”Local Infrastructure” in order to provide intelligent, transparent and adaptable services to the user and solves the problem of local context control. Authors present a conceptual model for development of local infrastructure, an architecture design to control the service offered by the local infrastructure. This infrastructure proposed consists of an intelligent device network to link the personal portable device with the contextual services. The device design is modular, flexible, scalable, adaptable and reconfigurable remotely in order to tolerate new demand services whenever is needed. Finally, the result suggests that authors will be able to develop a wide range of new and useful applications, not conceived at origin. The use of mobile devices with possible connection to the Internet is increasing tremendously. This mobility poses new challenges at various levels, including hardware, network services, and the development of applications. The user searches small and lightweight devices, easy to use, and with vast autonomy in terms of energy. She/He seeks also to connect the Internet “every time, everywhere”, possibly using different access technologies. Given the interface limitations, and processing capabilities of small mobile devices, the software and the operating system used must be necessarily adapted. Chapter 32, Network Mobility and Mobile Applications Development, overviews the mobility area, provides deep insight in the field, and presents the main existing problems. Mobility and the development of mobile applications are closed related. The advances in network mobility lead to different approaches in the mobile applications development. The chapter proposes a model for developing mobile applications, based on our research. Wireless sensor networks are composed of geographically dispersed sensors that work together to monitor physical or environmental conditions. In addition, wireless sensor networks are used in many industrial, social, and regulatory applications, including industrial process monitoring and control, environment and habitat monitoring, healthcare, home automation, and traffic control. Developers of wireless sensor networks face a number of programming and deployment challenges. Chapter 33, Building Mobile Sensor Networks Using Smartphones and Web Services: Ramifications and Development Challenges, shows how smartphones can help reduce the development, operation, and maintenance costs of wireless sensor networks, while also enabling these networks to use web services, high-level programming APIs, and increased hardware capability, such as powerful microprocessors. Moreover, this chapter examines key challenges associated with developing and maintaining a large wireless sensor network and presents a novel smartphone wireless sensor network that uses smartphones as sensor nodes. The work is validated in the context of Wreck Watch, which is a smartphone-based sensor network for detecting traffic accidents that authors use to demonstrate solutions to multiple challenges in current wireless sensor networks. The authors also describe common pitfalls of using smartphones as sensor nodes in wireless sensor networks and summarize how have addressed these pitfalls in Wreck Watch. Modern life makes people internet-dependents. They want to move connected and care for always getting the best options for connectivity, hoping between providers. Freedom for choosing providers and the business options which these exchanges can offer are the motivations for Chapter 34, Technologies to improve the quality of handovers: Ontologies, Contexts and Mobility Management. After pointing out some characteristics which make the basics of the current handover technologies, we describe an information infrastructure, based on context and ontologies which can be used to foster an intelligent, efficient and profitable scenario for managing handovers in the Next Generation Networks. Some experiments are described and the potential of using these technologies are evaluated. In smart environments, making a location-aware personal computing working accurately is a way of getting close to the pervasive computing vision. The best candidate to determine a user location in
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indoor environment is by using IEEE 802.11 (Wi-Fi) signals, since it is more and more widely available and installed on most mobile devices used by users. Unfortunately, the signal strength, signals quality and noise of Wi-Fi, in worst scenario, it fluctuates up to 33% because of the reflection, refraction, temperature, humidity, the dynamic environment, etc. Chapter 35, Making Location-Aware Computing Working Accurately in Smart Spaces, presents the current development on a light-weight algorithm, which is easy, simple but robust in producing the determination of user location using WiFi signals. The algorithm is based on "multiple observers" on ηk-Nearest Neighbour. The authors extend the approach in the estimation indoor-user location by using combination of different technologies, i.e. WiFi, GPS, GSM and Accelerometer. The algorithm is based on opportunistic localization algorithm and fuse different sensor data in order to be able to use the data which is available at the user position and processable in a mobile device. Context-aware computing is a class of mobile computing that can sense its physical environment and adapt its behavior accordingly; it is a component of the ubiquitous or pervasive computing environment that has become apparent with innovations and challenges. Chapter 36, User Pro-Activities Based on Context History, reviews the concept of context-aware computing, with focus on the user activities that benefit from context history. How user activities in the smart environment can make use of context histories in applications that apply the concept of context prediction integrated with user pro-activity is explored. A brief summary of areas which benefit from these technologies as well as corresponding issues are also investigated. The ten chapters of Section 2, Emerging Technologies, introduce emerging technologies able to dictate a complete shift of applications and services towards ubiquity. Advances in wireless, sensor, mobile and wearable technologies present new challenges for data mining research on providing mobile applications with intelligence. Autonomy and adaptability requirements are the two most important challenges for data mining in this new environment. In Chapter 37, Research Challenge of Locally Computed Ubiquitous Data Mining, the authors analyse the challenges of designing ubiquitous data mining services by examining the issues and problems while paying special attention to context and resource awareness. The authors focused on the autonomous execution of a data mining algorithm and analyzed the situational factors that influence the quality of the result. Already existing solutions in this area and future directions of research are also covered. Chapter 38, Emerging Wireless Networks for Social Applications, describes the implementation and performance evaluation of a novel routing protocol called Pandora, designed for social applications, and that can be implemented in a broad number of devices, such as commercial wireless routers and laptops. It also provides a robust backbone integrating and sharing data, voice and video between computers and mobile devices. Pandora offers great performance with both fixed and mobile devices and includes important features such as: geographic positioning, residual battery energy monitoring, and bandwidth utilization. In addition, Pandora also considers the number of devices attached to the network. Pandora is experimentally evaluated in a testbed with laptops for the first stage and commercial wireless routers for the second stage. The main goal of Pandora is to provide a reliable backbone for social applications requiring a quality of service (QoS) guarantee. With this in mind, the following evaluation of Pandora considers the following types of traffic sources: transport control protocol (TCP), voice, video and user datagram protocol (UDP) without marks. Pandora is also compared with different queuing disciplines, including: priority queuing discipline (PRIO), hierarchical token bucket (HTB) and DSMARK. Finally, an Internet radio transmission is employed to test the network re-configurability. Results show that queuing the PRIO and HTB disciplines, which prioritizes UDP traffic, performed the best.
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Several complex and time-critical applications require the existence of novel distributed, heterogeneous and dynamic platforms composed of a variety of fixed and mobile processing nodes and networks. Such platforms, that can be called Pervasive Mobile Grids, aim to merge the features of Pervasive Computing and High-performance Grid Computing onto a new emerging paradigm. In this chapter we study a methodology for the design and the development of high-performance, adaptive and context-aware applications. Chapter 39, “An Approach to Mobile Grid Platforms for the Development and Support of Complex Ubiquitous Applications”, describes a programming model approach, and the authors compare it with other existing research works in the field of Pervasive Mobile Computing, discussing the rationales of the requirements and the features of a novel programming model for the target platforms and applications. In order to exemplify the proposed methodology, the authors introduce the programming framework ASSISTANT, and provide some interesting future directions in this research field. Potentially, in the mobile computing scenario, the users can move in different environments and the applications can automatically explore their surroundings. This kind of context-aware application is emerging, but is not yet widely disseminated. Based on perceived context, the application can modify its behavior. This process, in which software modifies itself according to sensed data, is named Adaptation and constitutes the core of Ubiquitous Computing. The ubiquitous computing scenario brings many new problems such as coping with the limited processing power of mobile devices, frequent disconnections, the migration of code and tasks between heterogeneous devices, and others. Current practical approaches to the ubiquitous computing problem usually rely upon traditional computing paradigms conceived back when distributed applications where not a concern. Holoparadigm (Holo) was proposed as a model to support the development of distributed systems. Based on Holo concepts, a new programming language called HoloLanguage (HoloL) was created. Chapter 40, Towards a Programming Model for Ubiquitous Computing, propose the use of Holo for developing and executing ubiquitous applications, explore the HoloL for ubiquitous programming and propose a full platform to develop and execute Holo programs. The execution environment is based on a virtual machine that implements the concepts proposed by Holo. The Virtual Enterprise (VE) is a collaboration model between multiple business partners in a value chain that aims to cope with turbulent business environments, mainly characterized by demand unpredictability, shortening product lifecycles, and intense cost pressures. The VE model is particularly viable and applicable for SME and industry parks containing multiple SMEs that have different vertical competencies. As small firms collaborate effectively under VE model, it will be only possible to emerge products by joining their diverse competencies and mitigate the effects of market turbulence by minimizing their investment. A typical VE model has four phases; opportunity capture, formation, operation, and dissolution. The goal of Chapter 41, An Agent-Based Operational Virtual Enterprise Framework Enabled by RFID, is to present a conceptual VE framework, focusing on operation phase, that incorporates Multi Agent Systems (MAS) and Radio Frequency Identification Systems (RFID) which are emerging from research to industry with a great momentum. First, state of the art for VE and the two key enabling technologies are covered in detail. After presenting conceptual view of the framework, an Information and Communication Technology (ICT) view is also given to enhance technical integration with available industry standards and solutions. Finally, process views of how a VE can operate utilizing agent based and RFID systems in order to fulfill operational requirements, are presented. Chapter 42, Ontological Dimensions of Semantic Mobile Web 2.0. First Principles, advances, from the point of view of Knowledge Representation and Reasoning, an analysis of which ontological dimensions are needed to develop Mobile Web 2.0 on top of Semantic Web. This analysis will be particularly focused on social networks and it will try to make an outlook about the new knowledge challenges on
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this field. Some of these new challenges will be linked to Semantic Web context, while others will be inherent to Semantic Mobile Web 2.0. Unobtrusiveness is a key factor in usability of mobile and ubiquitous computing systems. These systems are made of several ambient and mobile devices whose goal is supporting everyday life users’ activities, hopefully without interfering with them. We intend to address the topic of obtrusiveness by assessing its impact in the design of interfaces for mobile and ubiquitous computing systems. The authors of Chapter 43, Unobtrusive Interaction with Mobile and Ubiquitous Systems, will make the case of how unobtrusive interfaces can be designed by means of Kinetic User Interfaces: an emerging interaction paradigm where input to system is provided through coordinated motion of objects and people in the physical space. A huge amount of information is used nowadays by modern vehicles, and it may be accessed through an On Board Diagnosis (OBD) connection. A technique using the already installed OBD system to communicate with the vehicle together with a Global Position System (GPS) provides reliable data which allow a detailed analysis of real on road tests. Different kinds of circulation circuits (urban, extra-urban and highway) were analyzed in Chapter 44, Impact of Advances on Computing and Communication Systems in Automotive Testing, using the capabilities of OBD II installed on the tested vehicles. OBD provides an important set of information, namely related with data on the engine, fuel consumption, chassis and auxiliary systems and also on combustion efficiency. The use of GPS in all the road tests performed provides important information to further determine the more sustainable from all the different solutions tested, considering the different situations imposed on each circuit. It is a fact that bench tests or a chassis dynamometer allow a fine control of the operation conditions; however the simulation is not as real as on the road. So the present methodology will allow the possibility to perform tests on the road, allowing enough control on vehicles and providing complete information of the chosen route and of the trip history. This is a possibility that ensures new tools with more reliable data which can give faster answers for the development of high efficiency, economic and environmentally neutral automotive technologies. RFID (Radio Frequency Identification) technology consists of a tag that can be used to identify an animal, a person or a product, and a device responsible for transmitting, receiving and decoding the radio waves. RFID tags work in two different modes: they wake up when they receive a radio wave signal and reflect it (Passive Mode) or they emit their own signal (Active Mode). The tags store information which allows univocally identifying something or someone. That information is stored in an IC (Integrated Circuit) which is connected to an antenna, responsible for transmitting the information. An evolution of this technology is the Near Field Communication (NFC). It consists of a contactless Smart Card technology, based in short-range RFID. Currently, there are mobile phones with NFC embedded in such a way that they work both as a tag and as a NFC reader. These technologies will be widely available both in mobile phones and other devices (e.g. personal digital assistants, etc.) in the near future allowing us to get closer to a ubiquitous and pervasive world. Chapter 45, RFID and NFC in the Future of Mobile Computing describe the most important aspects of RFID and NFC technology, illustrating their applicative potential, and provides a vision of the future in which the virtual and real worlds merge together as if an osmosis took place. Chapter 46, A Multi-Loop Development Process for a Wearable Computing System in Autonomous Logistics, examines a multi-loop development process for a wearable computing system within a new paradigm in logistic applications. The implementation of this system will be demonstrated by an example from the field of autonomous logistics for automobile logistics. The development process is depicted from
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selecting and combining hardware through to the adjustment to both user and operative environment. Further, this chapter discusses critical success factors like robustness and flexibility. The objective is to present problems and challenges as well as a possible approach to cope with them. The next chapters, that form Section 3 Critical Success Factors, address the critical success factors affecting the full exploitation of the potential of the services and applications of mobility and computing. A proper development of computing which penetrate our society more thoroughly with the availability of broadband services is provided by varied cooperative networks. However, the success of social dimension of computing requires collaboration within a multicultural environment to be considered. Aim of Chapter 47, Collaboration within Social Dimension of Computing: Theoretical Background, Empirical Findings and Practical Development, is to analyze collaboration within the social dimension of computing on the pedagogical discourse. The meaning of the key concepts of social dimension of computing, collaboration and its factors is studied within the search for the success of social dimension. The manuscript introduces the study conducted within the Baltic Summer School Technical Informatics and Information Technology in 2009. The conducted explorative research comprises four stages: exploration of the contexts of collaboration, analysis of the students’ needs (content analysis), data processing, analysis and data interpretation, and analysis of the results and elaboration of conclusions and hypothesis for further studies. Many factors converge when attempting to define the most adequate mobile learning model to be applied in a face-to-face university environment. As far as innovation related processes go, the implementation of mobile learning, implies defining a road map on the basis of strategic planning. It is also important to apply an action research approach in the implementation process of the model. In analyzing in depth this innovative mobile learning process, there are key factors to consider. First, there are factors related to the technology necessary for the implementation of the model—both hard and soft requirements. Second, there are cultural issues related to the use of non-native internet professors of innovative technologies. Finally, there are challenges related to defining, exactly, those educational strategies to be handled through mobile devices. Chapter 48, Critical Factors In Defining The Mobile Learning Model. An Innovative Process For Hybrid Learning At The Tecnologico De Monterrey, A Mexican University, focuses on the critical factors involved in integrating mobile learning into a hybrid educational model at a Mexican university. The purpose of Chapter 49, Critical Human Factors on Mobile Applications for Tourism and Entertainment, is to research some principles that can guide the design, development and marketing of mobile applications, with a particular focus on the tourism and entertainment application domains. This research also fills a gap concerning impact studies of mobile applications, since the majority of the literature available today is more focused on the design and development process and results. Besides describing a set of novel mobile applications, we aim at providing an overview on innovation processed used, and conducting several experiences, gathering results from questionnaires, surveys, log data and our own observations. Regarding the mobile tourism domain, the author studied the impact of media visibility, the impact of novel interaction paradigms. Regarding the mobile entertainment applications, he focused on studying the impact brought that realism and graphics quality have on mobile games. Internet surveys offer important advantages over traditional survey methods: they can accomplish large samples within a relatively short period of time, questionnaires may have visual and navigational functionalities impossible to implement in paper-and-pencil questionnaires, data is more efficiently processed since it already comes in electronic format and costs can be lower. But the use of the Internet for survey purposes raises important concerns related to population coverage, lack of suitable sampling
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frames and non-response. Despite its problems, Internet-based surveys are growing and will continue to expand presenting researchers with the challenge of finding the best way to adapt the methods and principles established in survey methodology to this new mode of data collection in order to make best use of it. Chapter 50, Internet Surveys: Opportunities and Challenges, describes the positive features of the Internet for survey activity and examines some of the challenges of conducting surveys via the Internet by looking at methodological issues such as coverage, sample selection, non-response and data quality. The purpose of Chapter 51, EPS A Coalition-Based Production Approach, is to provide broad view of the rationale, fundamental principles, current developments and applications for Evolvable Production Systems (EPS). Special attention is given to how complexity is handled, the use of agent based and wireless technology, and how economical issues are affected by having an evolvable system. The rationale for EPS is based on current road mapping efforts, which have clearly underlined that true industrial sustainability requires far higher levels of system autonomy and adaptivity than what can be achieved within current production system paradigms. Since its inception in 2002 as a next generation of production systems, the EPS concept has been further developed and tested to emerge as a production system paradigm with technological solutions and mechanisms that support sustainability. Technically, EPS is based on the idea of using several re-configurable, process-oriented, agent-based and wireless intelligent modules of low granularity. This allows for a continuous adaption and evolution of the production system and the ability to explore emergent behavior of the system, which are imperative to remain fit with regards to the system environment. The proposal of new business models, based on the emerging novelty and huge opportunities of mobility and computing is the theme of the next four chapters, which compose Section 4 New Business Models. As mobile applications increase in popularity, the issue of how to build viable business models for the m-commerce industry is becoming a clear priority for both organizations and researchers. In order to address this issue, this chapter, Viable Business Models for M-Commerce: The Key Components, reports on five mini cases used as a guideline, and applies the theoretical business model from Chesbrough and Rosenbloom (2002) to each of them to find out the most important components of viable business models for their m-commerce applications. The study then uses cross cases analysis as a research tool to compare and contrast each of the mini cases and to find out how the different organizations fit within the researched theoretical business model. Finally, this chapter confirms that there are 7 important components of viable business models for m-commerce which are: value proposition, market segment, value chain, profit potential, value network, competitive strategy and firm capabilities. This study also highlights the fact that the public visibility of these 7 components is uneven. Some components such as value proposition, value chain, value network and firm’s capabilities are more likely to be presented in public by organizations. However, aspects such as cost structure and profit potential, market segment and competitive strategy are more likely to be hidden from the public due to their commercial sensitivity. Mobility is a relatively recent topic in the enterprise arena, but thanks to the widespread use of cell phones it has already changed much of the business landscape. It should be integrated in enterprise architectures (EAs) as an intrinsic feature and not as an add-on or as an afterthought transition. Current EA frameworks were not designed with mobility in mind and are usually based on the process paradigm, emphasizing functionality. Although the issue of establishing a systematized migration path from a nonmobile EA to a mobile one has already been tackled, the need for mobile-native EA modeling frameworks is still felt. Chapter 53, A Service-Based Framework to Model Mobile Enterprise Architectures, presents and discusses a resource-based and service-oriented metamodel and EA framework, in which mobility is introduced naturally from scratch, constituting the basis for some guidelines on which EA resources
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should be mobilized. Several simple scenarios are presented in the light of this metamodel and framework. Although mobile phones have become an extension of the workplace, organizations are still exploring their effectiveness for employee training and development. A 2009 joint collaborative study between Columbia University (New York, USA) and IBM of 400 IBM employees’ use of mobile phones revealed unexpected insights into how employees use mobile applications to improve job performance. The findings are reshaping IBM Learning's mobile technologies strategy for networking, collaboration, and skills improvement. Research-Based Insights Inform Change in IBM M-Learning Strategy reveals the study's results and IBM's new direction for m-learning, highlighting IBM’s preparedness for a shift in its organizational learning model potentiated by ubiquitous access and mobility. Location-based mobile services (LBMS) are at present an ever growing trend, as found in the latest and most popular mobile applications launched. They are, indeed, supported by the hasty evolution of mobile devices capabilities; by users demand; and, lastly, by market drive. With e-commerce, products and services started arriving to potential customers through desktop computers, where they can be bought and fast delivered to a given address. However, expressions such as “being mobile”, “always connected”, “anytime anywhere” that already characterize life in the present will certainly continue to do so in the near future. Meanwhile, mobile devices centred commerce services seem to be the next step. Therefore, Chapter 55, Location Based E-commerce System: An Architecture, presents a system architecture designed for location-based e-commerce systems. These systems, where location plays the most important role, enable a remote products/services search, based in user parameters: after a product search, shops with that products are returned in the search results and are displayed in a map, around the user present location; and services like obtaining more information, reserving and purchasing are made available as well. This concept represents a mix between traditional client-oriented commerce and faceless mass-oriented e-commerce, enabling a proximity-based user-contextualized system, being well capable of conveying significant advantages and facilities to both service-providers/retailers and users. The four chapters of Section 5, Security, address the topic of security in mobile systems and applications. Vehicular ad-hoc networks (VANETs) are a promising communication scenario. Several new applications are envisioned, which will improve traffic management and safety. Nevertheless, those applications have stringent security requirements, as they affect road traffic safety. Moreover, VANETs face several security threats. As VANETs present some unique features (e.g. high mobility of nodes, geographic extension, etc.) traditional security mechanisms are not always suitable. Because of that, a plethora of research contributions have been presented so far. Chapter 56, Overview of Security Issues in Vehicular Ad-hoc Networks, aims to describe and analyze the most representative VANET security developments. Access control in the domain of information system security refers to the process of deciding whether a particular request made by a user to perform a particular operation on a particular object under the control of the system should be allowed or denied. For example, the access control component of a file server might have to decide whether user “Alice” is allowed to perform the operation “delete” on the object “document.txt”. For traditional access control this decision is based on the evaluation of the identity of the user and attributes of the object. The novel idea of location-aware access control is also to consider the user’s current location which is determined by a location system like GPS. The main purpose of Chapter 57, Modelling of Location-Aware Access Control Rules, is to present several approaches for the modeling of location-aware access control rules. The aim of Chapter 58, Secure Techniques for Remote Reconfiguration of Wireless Embedded Systems, is to give a thorough overview of secure remote reconfiguration technologies for wireless embedded systems, and of the communication standard commonly used in those systems. In particular, we focus
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on basic security mechanisms both at hardware and protocol level. We will discuss the possible threats and their corresponding impact level. Different countermeasures for avoiding these security issues are explained. Finally, we present a complete and compact solution for a service-oriented architecture enabling secure remote reconfiguration of wireless embedded systems, called the STRES system. The evolution of computer networking is moving from static wired networking towards wireless, mobile, infrastructureless, and ubiquitous networking. In next-generation computer networks, new mobility features such as, seamless roaming, vertical handover, and moving networks are introduced. Security is a major challenge in developing mobile and infrastructureless networks. Specific security threats in next-generation networks are related to the wireless access mediums, routing, and mobility features. Chapter 59, Secure Routing and Mobility in Future IP Networks, identifies these threats, and discuss the state of the art of security research and standardization within the area, proposing security architectures for mobile networking. A survey of security in routing is provided with special focus on mobile ad hoc networks (MANETs). The security of currently relevant protocols for management or node and network mobility, Mobile IP (MIP), Network Mobility (NEMO), Mobile Internet Key Exchange (MOBIKE), Host Identity Protocol (HIP), Mobile Stream Control Transmission Protocol (mSCTP), Datagram Congestion Control Protocol (DCCP), and Session Initiation Protocol (SIP), is described. Section 6 Applications, Surveys and Case Studies is focused on the presentation of a wide variety of new applications and solutions, surveys related with adoption of technologies and case studies, along its 18 chapters. In an educational context, technological applications and their supporting infrastructures have been evolved in a way that the use of learning objects is no longer limited to a personal computer, but has been extended to a number of mobile devices. Such evolution leads to the creation of a technological model called m-learning that offers great benefits to education. This educational model resulted in several research projects and some commercial products. Chapter 60, Evaluation of a Mobile Platform to Support Collaborative Learning: Case Study, describes the (re)use of an adapted platform from an API of MLE (Mobile Learning Engine), to create tests, quizzes, forums, SMS, audio, video, mobile learning objects, in combination with a learning platform in a particular setting. MLE is a special m-learning application for mobile phones (a J2ME application) that can access a LMS (Learning Management System) and use most of its activities and resources, and add new, even innovative, activities. With J2ME one can store, use content and learn without the need of further network access and even use interactive questions that can be directly solved on mobile devices. The MLE enables one to use the mobile phone as a constant way of learning. As a consequence it is possible to use every spare time to learn, no matter where we are, providing new opportunities to enhance learning. Wireless ad-hoc and sensor networks are experiencing a widespread diffusion due to their flexibility and broad range of potential uses. Nowadays they are the underlying core technology of many industrial and remote sensing applications. Such networks rely on battery-operated nodes with a limited lifetime. Although, in the last decade, a significant research effort has been carried out to improve the energy efficiency and the power consumption of the sensor nodes, new power sources have to be considered to improve node lifetime and to guarantee a high network reliability and availability. Energy scavenging is the process by which the energy derived from external sources is captured, translated into an electric charge and stored internally to a node. At the moment, these new power sources are not intended to replace the batteries, since they cannot generate enough energy; however, working together with the conventional power sources they can significantly improve node lifetime. Low-power operation is the result of a complex cross-layer optimization process, for this reason, this chapter “Power Issues and
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Energy Scavenging in Mobile Wireless ad-hoc and Sensor Networks”, thoroughly reviews all the traditional methods aimed at reducing power consumption at network, MAC and PHY levels of the TCP stack, to understand advantages and limitations of such techniques, and to justify the need of alternative power sources that may allow, in the future, the design of completely self-sustained and autonomous sensor nodes. Chapter 62, A Low Cost Wireless Sensors Network with Low-Complexity and Fast-Prototyping, presents a low cost/fast prototyping wireless sensors network that was designed for a huge range of applications and making use of low cost commercial of the shelf components. Such applications includes industrial measurements, biomedical, domestic monitoring, remote sensing, among others. The concept of the wireless sensor network is presented and simultaneously, hot topics and their implementation are discussed. Such topics are valuable tools and can't be discarded when a wireless sensors network is planed. By the contrary, such tools must be taken in account to make the communications between the nodes and the base station the best possible reliable. The architecture, protocols and the reasons that were behind the selection of the components are also discussed. The chapter also presents performance metrics that are related to with the physical characteristics of sensors and with the radio specificity. Microcontrollers with a RISC architecture are used by the network nodes to control the communication and the data acquisition and operate in the 433 MHz ISM band with ASK modulation. Also, in order to improve the communication and to minimise the lost of data, it is predicted to put the wireless nodes to handle line and source coding schemes. Failure detection is an important abstraction for the development of fault-tolerant middleware, such as group communication toolkits, replication and transaction services. Unreliable failure detector (namely, FD) can be seen as an oracle which provides information about process failures. The dynamics and selforganization of Mobile Ad-hoc Networks (MANETs) introduce new restrictions and challenges for the implementation of FDs with which static traditional networks do not have to cope. It is worth mentioning that in some way, fault tolerance is more critical for MANETs than for the latter, since wireless network can present high error rates and mobile nodes are more prone to failures, physical damages or transient disconnections. The aim of Chapter 63 Unreliable Failure Detectors for Mobile Ad-hoc Networks is thus to discuss the impact of all these characteristics, intrinsic to MANET, in the implementation of FDs. It presents a survey of the few works about FD implementations for wireless networks, including the different possible assumptions to overcome the dynamics and lack of both global view and synchrony of MANETs. Adaptation of communication is needed to maintain the connectivity and quality of communication in group-wide collaborative activities. This becomes quite a challenge to handle when mobile entities are part of a wireless environment, in which responsiveness and availability of the communication system are required. In Chapter 64, Mission-Aware Adaptive Communication for Collaborative Mobile Entities, these challenges are addressed within the context of the ROSACE project where mobile ground and flying robots have to collaborate either between themselves or with remote artificial and human actors during save and rescue missions in the event of disasters such as forest fires. This chapter presents our first results. The final goal is to propose new concepts, models and architectures that supports cooperative adaptation which is aware of the mission being executed. Thus, the communication system can be adequately adapted in response to predictable or unpredictable evolutions of the activity requirements and to the unpredictable changes in the communication resource constraints. In the last years ontologies are being used in the development of pervasive computing applications. It is habitual their use for facilitating the interoperability among context-aware applications and the entities
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that may enter in the context at any time. Chapter 65 OntoHealth: An Ontology Applied to Pervasive Hospital Environments presents OntoHealth: an ontology applied to health pervasive environment and a tool to its processing. The main idea is that a hospital could be seen as this pervasive environment, where someone, through ubiquitous computing, engages a range of computational devices and systems simultaneously, in the course of ordinary activities, and may not necessarily even be aware that they are doing so. With the proposed ontology and the tool for its processing, the medical tasks can be shared by all components of this pervasive environment. Chapter 66 Adoption of Mobile and Information Technology in an Energy Utility in Brazil deals with the adoption of mobile technology. The case illustrated here is the implementation of mobile and wireless technology – MIT and smartphones – at an energy utility. The objective was to understand the human and social aspects of the adoption of this technology. This paper makes use of the metaphor of hospitality proposed by Ciborra in the late 1990s. The hospitality metaphor was a useful alternative for describing the process of adopting a new technology. It touches on technical aspects and notes human reactions that become evident when a technician comes across an unknown ‘guest’, the new technology: the doubtful character of the guest, the reinterpretation of the identities of guest and host during the process, learning through trial and error, the technology’s ‘drift’, the participants’ emotions and state of mind, and the appropriation of, and the care for, the new technology. Context-aware mobile applications are becoming popular, as a consequence of the technological advances in mobile devices, sensors and wireless networking. Nevertheless, developing a context-aware system involves several challenges. For example, what will be the contextual information, how to represent, acquire and process this information and how it will be used by the system. Some frameworks and middleware have been proposed in the literature to help programmers to overcome these challenges. Most of the proposed solutions, however, neither have an extensible ontology-based context model nor uses a communication method that allows a better use of the potentialities of the models of this kind, as discussed in Chapter 67 Infrastructures for Development of Context-Aware Mobile Applications. Chapter 68 A Practice Perspective on Transforming Mobile Work introduces a study that explores users’ experiences during an organizational implementation of a new mobile information technology in public home care environment. The home care case illustrates differences between implementation project goals and expectations, and on the other hand, the daily organizing and carrying out care work, where previously, no information technology was utilized. While implementing mobile technology was expected to enhance the efficiency of care working, the project outcomes include resistance due to surveillance aspect of the new technology as well as technological problems during the implementation. Successful outcomes of the implementation include better planning of working hours and more even distribution of work resources. In Chapter 69, Data Replication Support for Collaboration in Mobile and Ubiquitous Computing Environments, the authors address techniques to improve the productivity of collaborative users by supporting highly available data sharing in poorly connected environments such as ubiquitous and mobile computing environments. We focus on optimistic replication, a well known technique to attain such a goal. However, the poor connectivity of such environments and the resource limitations of the equipments used are crucial obstacles to useful and effective optimistic replication. The authors analyze state-of-the art solutions, discussing their strengths and weaknesses along three main effectiveness dimensions: (i) faster strong consistency, (ii) with less aborted work, while (iii) minimizing both the amount of data exchanged between and stored at replicas; and identify open research issues.
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Wireless Local Area Networks are very useful for the most applications based on network. It can be developed in almost all environments and products are cheap and robust. Moreover, these networks can be formed by different devices with wireless interfaces like IP cameras, laptops, PDAs, sensors, etc. WLANs provide high bandwidth at large coverage areas, which it is necessary in many applications at different research areas. All these characteristics let WLANs be a useful technology to provide ubiquity for any type of service. If they are deployed from a good and exhaustive design, they can provide connection to any device, everywhere at anytime. Chapter 70, Providing Outdoor and Indoor Ubiquity with WLANs, presents a complete guideline about how to design and deploy WLANs and to get their best performance. The authors start from an analytical point of view and we use mathematical expressions to design WLANs in both indoor and outdoor environments. Then, the authors introduce a method proposed by some authors of this chapter some years ago and how it can be used to design WLANs in indoor environments. The authors also show WLANs design in outdoor environments and describe two projects developed in order to provide ubiquity in real indoor and outdoor environments. Chapter 71, INTIC for Mobile Devices: Support System for Communication with Mobile Devices for the Disabled introduces the In-TIC system for mobile devices Integration with ICT system for mobile devices) that represents an approach towards the area of technical aids for mobile devices. The mobile telephone is a device that makes our lives easier, allowing us to be permanently accessible and in contact, to save relevant information, and also for entertainment purposes. However, people with visual, auditory or motor impairment or the elderly still find these devices difficult to use. They have to overcome a range of difficulties when using mobile telephones: the screens are difficult to read, the buttons are too small to use, and the technical features are too complicated to understand. At present, the main advances in mobile technology have been aimed at improving multimedia-messaging services and reproducing videos and music. This new support system adds accessibility to mobile telephones, making them easier to use for the people who need them the most, people with reduced physical or mental capacities who cannot use a conventional mobile. Granxafamiliar.com is a project for developing the Galician rural milieu both socio-economically and culturally in order to appreciate the quality of life and rural culture, to create communication links between the rural and urban world, to emphasize the importance of the traditional self-supply production market of Galician family farms, and to promote the spread of new technologies as a social intervention tool against the phenomenon of social and territorial exclusion known as the “Digital Divide". The authors of New Ways to Buy and Sell: An Information Management Web System for the Commercialization of Agricultural Products from Family Farms without Intermediaries are planning the architecture of www.granxafamiliar.com, which is developing the creation of a virtual community based on boosting commercial transactions and the possibilities for buying and selling traditional self-supply products that exist in the rural environment. The authors expect to promote it globally across the Internet by promoting the use and spread of ICTs as tools and commercial channels for agricultural products and intend to carry out an in-depth empirical and theoretical study of the territorial and social effects linked to the development of the information and communication society in rural communities. Their aim is to assist the progress of public decision-making and administrative efficiency for when the time comes to invest in suitable services and activities related to the information society in the rural environment. The continuous growth of the available throughput, especially in the uplink of mobile phone networks is opening the doors to new services and business opportunities without references in the past. In more concrete, new standards HSDPA/HSUPA, introduced to complement and enhance 3G networks, together with the advances in audio and especially video coding, like those adopted by the standard H.264 AVC
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have boosted the appearance of a new service: exploiting the mobile telephony networks for contributing broadcast quality videos. This new service is offering just now a low cost, high flexibility alternative that, in a brief period of time, will substitute the current Electronic News Gathering (ENG) Units, giving rise to what is being to be called Wireless Journalism (WENG or WiNG). Chapter 73, Broadcast Quality Video Contribution in Mobility, discusses both the technologies involved and the business opportunities offered by this sector. Once reviewed the state of the art, different solutions will be compared, some of them recently appeared as commercial solutions, like QuickLink 3.5G Live Encoder or AirNow! and others still in research and development processes. Mobile devices are rapidly becoming the most common interface for accessing network resources (Hall 2008). By 2015 the average 18-year old will spend the majority of their computing time on mobile devices (Basso 2009). These trends directly affect institutions of higher learning. Many universities are offering learning initiatives and m-services designed to distribute content and services to mobile devices. Chapter 74, Mobile Device Selection in Higher Education: iPhone vs. iPod Touch, reports findings from an exploratory, longitudinal study at Abilene Christian University, where incoming freshmen received their choice of an Apple iPhone or iPod touch. The findings indicate that users' device selections were affected by their perceptions of the costs of the devices, the devices' relative characteristics, and the social influence of parents. We also found that users' attitude, satisfaction, and confidence about their device selection varied across devices, with iPhone users having more favorable perceptions. The chapter concludes with recommendations for mobile learning initiatives and directions for future research. Chapter 75, Design of Wearable Computing Systems for Future Industrial Environments, investigates the role of context, particularly in future industrial environments, and elaborates how context can be incorporated in a design method in order to support the design process of wearable computing systems. The chapter is initiated by an overview of basic research in the area of context-aware mobile computing. The aim is to identify the main context elements which have an impact upon the technical properties of a wearable computing system. Therefore the authors describe a systematic and quantitative study of the advantages of context recognition, specifically task tracking, for a wearable maintenance assistance system. Based upon the experiences from this study, a context reference model is proposed, which can be considered supportive for the design of wearable computing systems in industrial settings, thus goes beyond existing context models, e.g. for context-aware mobile computing. The final part of this chapter discusses the benefits of applying model-based approaches during the early design stages of wearable computing systems. Existing design methods in the area of wearable computing are critically examined and their shortcomings highlighted. Based upon the context reference model, a design approach is proposed through the realization of a model-driven software tool which supports the design process of a wearable computing system while taking advantage of concise experience manifested in a well-defined context model. In 2002, Belgium has adopted an electronic identity card as one of the first countries in Europe. By the end of 2009, the roll-out of the eID card will be completed, and this means that each Belgian citizen will possess an eID card. The card enables her to digitally prove her identity and to legally sign electronic documents. The Belgian eID card opens up new opportunities for the government, its citizens, service providers and application developers. The Belgian eID technology originally aimed at facilitating transactions between Belgian citizens and the government and although many eID applications have been developed, the success of the Belgian eID technology has not been what was expected. Therefore, the Belgian government encourages developers to build commercial applications that use the eID card (for authentication or e-signatures). However, extending the scope of the Belgian eID technology from
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e-government to the commercial sector is no sinecure and not without risks. These issues are analysed in Extending the Scope of eID Technology: Threats and Opportunities in a Commercial Setting. Mobile information work, an extreme type of information work, is progressively becoming commonplace in various corporations. The availability of cheap and portable information technologies as well as the development of pervasive communication infrastructure in some parts of the world is creating scenarios where people can work from almost anyplace. Nevertheless up to now there has not been sufficient research on the particular work practices and strategies these professional workers use to be productive as they face the particular challenges of being mobile. Based on an ethnographic investigation of the experiences of mobile professional workers in a multi-national accountancy company, Chapter 77 Mobility and Connectivity: On the Character of Mobile Information Work, discusses some characteristics defining the character of modern information work with regards mobility and connectivity while operating outside the workplace. The study highlights the importance of: location in terms of providing an adequate atmosphere and infrastructure to conduct work; regularity in terms of giving workers flexibility to connect and reconnect whenever it was more convenient for them; space in terms of letting people preserve and reconstruct their information workspaces; and balance while juggling between personal and work related commitments. The findings presented can be useful for defining the processes and technological tools supporting mobile professional workers.
EXPECTATIONS Along these 77 chapters, the reader is faced with the discussions and confirmation of the relevance and impact of this hot topic, providing professionals, researchers and scholars, with some of the most advanced research developments, solutions, state-of-the-art enabling technologies, discussions and case studies on mobility and computing. The handbook is expected to support a professional audience of top managers, IT professionals, technology solution providers and an academic audience (teachers, researchers and students, mainly of post-graduate studies). As an academic tool, it can be a support to disciplines of post-graduate studies on IT/IS. We hope you find it useful. Enjoy your reading and study! Maria Manuela Cruz-Cunha Polytechnic Institute of Cávado e Ave, Portugal Fernando Moreira Universidade Portucalense, Portugal
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Acknowledgment
Editing a book is a quite hard but compensating and enriching task, as it involves a set of different activities like contacts with authors and reviewers, discussion and exchange of ideas and experiences, process management, organization and integration of contents, and many other, with the permanent objective of creating a book that meets the public expectations. And this task cannot be accomplished without a great help and support from many sources. As editors we would like to acknowledge the help, support and believe of all who made possible this creation. First of all, the edition of this book would not have been possible without the ongoing professional support of the team of professionals of IGI Global. We are grateful to Dr. Mehdi Khosrow-Pour and to Mrs. Jan Travers, Managing Director, for the opportunity and belief in this project. A very very special mention of gratitude is due to Mrs. Christine Bufton, Assistant Development Editor, and to Mr. Dave DeRicco and Mr. Michael Killian, Editorial Assistants, for their highly professional support and friendly words of advisory, encouragement and prompt guidance. We also address our recognition and appreciation to all the staff at IGI Global, whose contributions throughout the process of production and making this book available all over the world was invaluable. We are grateful to all the authors, for their insights and excellent contributions to this book. Also we are grateful the authors who simultaneously served as referees for chapters written by other authors, as well as to the external referees and to the members of the editorial advisory board, for their insights, valuable contributions, prompt collaboration and constructive comments. Thank you all, authors and reviewers, you made this book! The communication and exchange of views within this truly global group of recognized individualities from the scientific domain and from industry was an enriching and exciting experience! We are also grateful to all who accede to contribute to this project, some of them with high quality chapter proposals, but unfortunately, due to several constraints could not have seen their work published. Thank you. Maria Manuela Cruz-Cunha Polytechnic Institute of Cávado e Ave, Portugal Fernando Moreira Universidade Portucalense, Portugal
Section 1
Mobile Technologies
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Chapter 1
Evaluating the Context Aware Browser:
A Benchmark for Proactive, Mobile, and Contextual Web Search Davide Menegon University of Udine, Italy Stefano Mizzaro University of Udine, Italy Elena Nazzi University of Copenhagen, Denmark Luca Vassena University of Udine, Italy
ABSTRACT The authors discuss the evaluation of highly interactive and novel context-aware system with a methodology based on a TREC-like benchmark. We take as a case study an application for Web content perusal by means of context-aware mobile devices, named Context-Aware Browser. In this application, starting from the representation of the user’s current context, queries are automatically constructed and used to retrieve the most relevant Web contents. Since several alternatives for query construction exist, it is important to compare their effectiveness, and to this aim we developed a TREC-like benchmark. We present our approach to early stage evaluation, describing our aims and the techniques we apply. The authors underline how, for the evaluation of context-aware retrieval systems, the benchmark methodology adopted can be an extensible and reliable tool. DOI: 10.4018/978-1-60960-042-6.ch001 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.
Evaluating the Context Aware Browser
INTRODUCTION The diffusion of mobile devices and real-world mobile users have moved the static world of classical and Web Information Retrieval (IR) towards a dynamic and evolving context-based world. The notion of context (roughly described as the situation the user is in), and the information it conveys, is gaining increasing importance for the development of new IR systems. The concepts of context and awareness convey to the dynamic nature of the user needs, to the complexity of the information available, and of the relevance of this information. When combined with context-awareness, IR has been named Context-Aware Retrieval (CAR) (Brown, 2001). Starting from considering only a low number of contextual features (location and time), current CAR systems entail such an amount of data that a new challenge for IR is how those data can enhance user satisfaction. How to evaluate the strategies and techniques that CAR systems use for this purpose is another challenge. CAR systems imply a high amount of interactivity with the user, and a user study seems the most sensible approach. But our approach is to evaluate highly interactive and novel contextaware systems on the basis of a TREC-like benchmark methodology. This paper describes our methodology, presents the results obtained, and discusses the general approach. The present work is related to the ContextAware Browser (CAB for short), a novel contextaware retrieval application. CAB allows a proactive context-aware Web content perusal by means of mobile devices. Since several alternatives for the retrieval process exist, it is important to compare their effectiveness to find the best approach. With this in mind, we propose an evaluation benchmark, discuss its limits, and test it. Although we focus on the needs of CAB, the problems to solve are typical of any proactive context-aware retrieval system.
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We first briefly survey evaluation methodologies in IR and in CAR systems (Sect. Related Work), introducing our case study application. We then present our early evaluation approach (Sect. Experimental Evaluation) describing aims, techniques, and results. We discuss the reliability and usefulness of our methodology in Sect. Discussion, while in Sect. Lessons Learned we present the lessons learned. Finally in Sec. Conclusions we draw some conclusion and present future work.
RELATED WORK Context-Aware Retrieval With the spread of the concepts related to context-aware computing, Information Retrieval has gained new and increasing importance. The newborn field of CAR, instead of concentrating only on topicality, incorporates contextual information into the retrieval process, aiming at discovering “the query behind the context”: to retrieve what the users need, even if they did not issue any query (Mizzaro, 2008). CAR systems are concerned with the acquisition and understanding of context, and with a behavior based on the recognized context. Thus the CAR model includes, among the elements of the classical IR model, the user’s context. This context is both used in the query formulation process and associated with the documents candidate for retrieval. Typical CAR applications present the following characteristics (Jones, 2004): a mobile user, i.e., a user whose context is changing; interactive or automatic actions, if there is no need to consult the user; time dependency, since the context may change; appropriateness and safety to disturb the user. Although CAR applications can be both interactive and proactive in their communication with the user, we concentrate on the proactive aspects, since they are more relevant to our proposal. Besides, we concentrate on the association between CAR and mobile application, as they
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can be considered as the prime field for CAR (Jones, 2004).
The Context-Aware Browser Idea & Architecture The Context Aware Browser (CAB) is a generalpurpose solution to Web content fruition by means of context-aware mobile devices. It allows a “physical browsing”: browsing the digital world based on the situations in the real world. The main idea behind CAB is to empower a generic mobile device with a browser able to automatically and dynamically load web pages, services and applications selected according to the current context the user is in. Despite the apparent simplicity of this approach, a more thorough definition has to take into account several features; whence, we can say that the Context-Aware Browser is best described by the sum of the following parts: •
•
•
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a Web browser: CAB is able to interpret and render in a sound way (X)HTML code, to interpret client side (e.g., JavaScript) code, and to fully exploit AJaX-based applications; a context-aware application: CAB is able to automatically retrieve and constantly update the contextual information gathered from the surrounding environment (this feature allows CAB to provide contents varying in dependence of the current context of the user); a search engine: CAB is able to search both for “traditional” web pages and applications on the Web and for specifically tailored applications, as we will see in the following; a proactive application able to automatically search for and download contents: the resources retrieved by the search engine are automatically filtered against user’s
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preferences and several other parameters, in order to reduce the cognitive load imposed on the user by automatically selecting the most appropriate contents; an application working on any kind of Web content, i.e., both Web pages and applications: CAB is able to manage both static resources (e.g., plain (X)HTML pages) and dynamic ones requiring user interaction (e.g., web applications).
The CAB acquires information related to the user and the surrounding environment, by means of sensors installed on the device or through external servers. This information, combined with the user’s personal history and the community behavior, is exploited to infer the user’s current context (and its likelihood) that is represented by a list of terms. In the subsequent retrieval process, starting from this list of terms, a query is automatically built and sent to an external search engine, in order to find the most suitable Web pages for the sensed context. In this paper we study different strategies to build automatically the query sent to the external search engine. We provide some more details on CAB implementation. Figure 1 shows CAB overall three-tiered architecture, where the topmost layer manages the interaction with the user, the medium layer bridges the topmost and the inner layer, which in turn is responsible for sensors, inferential network, and filtering engine management. The main modules of CAB architecture are: •
Context server and Sensors. They are responsible for collecting and sending to the CAB Core the contextual information gathered from the surrounding environment, in the form of an inferential network that represents (part of) the knowledge base of the Context manager. Then, all the sensors specified are instantiated by the Context manager. Such sensors communicate with the Context server in order to re-
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Figure 1. CAB architecture
•
•
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ceive the contextual information (location, date/time, temperature, etc.), in either push or pull mode. Context manager, and its internal inferential system are the core component responsible for the synthesis of the current context, starting from the contextual information gathered by sensors. Filter module and the Descriptor search engine are in charge to search for and filter the most suitable contents according to the
inferred context. The contextual information, obtained from the Context manager, is represented through a Context Descriptor that holds the most important information related to the user’s current context. CAB allows the user to specify which filtering information is public and which one is private to achieve a reasonable privacy level. Public information is used to formulate the query to be sent to the Descriptor search engine out of the device, while private in-
Evaluating the Context Aware Browser
•
•
formation is used in “internal” filtering activities only. Connector is an infrastructure component used to separate the user interface from the context management part. This abstraction allows to easily change the way users interact with the system, or to modify the techniques exploited for the current context inference and management. Currently, as the user interface is Web-browser based, the Connector is implemented as a local web server, being able to open HTTP connections and to manage browser’s requests. Browser module manages the presentation of the web contents to the user and it also automatically starts the most relevant ones. Such features are implemented in two submodules: the AJaX engine and the User interface.
Scenario To better understand the CAB functioning we present a simple example scenario, where we consider a tourist visiting a museum. As she enters the museum main hall with her own mobile device, a Web page with the list of the collections available in the museum is presented to her (e.g., the official museum home page, or a mobile adapted version). While the user action has simply been to enter the museum, the CAB has received, analyzed, and collected contextual information and then retrieved the associated resources. Moving around the museum the tourist is guided by the system that contextually retrieves the most interesting information (Figure 2): moving towards an artwork the tourist will automatically obtain the detailed description of that artwork. Because of the huge amount of information that is relevant to each artwork, the ubiquitous search has to be precise and has to provide only the information interesting and important for the tourist, based on her preferences, activities, interests and based on the community behavior
and on the accuracy of the same information. In fact, when the tourist comes near an artwork, the detailed description automatically provided, is accompanied with pictures, comments by experts or other tourists, etc. As usual, the most interesting artworks are surrounded by lots of people. In this case, since the user has to wait in the queue, she cannot yet see the painting, so probably she is not particularly interested in the detailed description. In this situation the system detects the crowd situation and retrieves different resources, like for example Web pages with podcasts about that artwork. If the tourist takes into consideration those resources the system annotates them with the tourist’s context; hence, other users arriving near the painting in crowded situations, are more likely to get the podcast or the text description otherwise.
Evaluation In the development of a CAR system for mobile environments, evaluation plays an important role, as it allows to measure the effectiveness of the system and to better understand problems from both the system and the user interaction point of view. The challenges for context-aware computing evaluation have been studied deeply (Scholtz, 2001; Carter, 2004). In particular these challenges are: the need to identify meaningful metrics (each single application has peculiar aspects to be evaluated that differ from other types of applications); the difficulty to evaluate in small scale a system that is meant to be adopted by many users; the explicit testing of a novel system, meant to be integrated in everyday life and thus invisible, as the basic vision of Ubiquitous computing (Weiser, 1991). Depending on resources and aims, different evaluation metrics are chosen and different evaluation approaches are adopted (e.g., user studies and benchmark; lightweight and heavyweight (Harper, 1997); etc.). As CAR applications are strictly related to users, the user-centered evaluation (live or in laboratory) seems the most natural
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Figure 2. CAB employed in a museum (iPhone and Android version) (a) List of available information and services;(b) Detailed contextual information
one. In (Scholtz, 2004), for example, a framework for user evaluations of ubiquitous computing has been proposed. A detailed work about metrics for evaluating systems for information access has been done in (Scholtz, 2006). More recently, in AmbieSense (Göker, 2008), a user centered, iterative, and progressive evaluation has been adopted combining IR evaluation methods with humancomputer interaction development techniques. Another largely adopted evaluation methodology is benchmark evaluation. Taking example from TREC initiative for large scale evaluation of IR effectiveness (http://trec.nist.gov/), benchmarks are defined by a collection of topics (expressions of user’s information needs), a collection of resources to retrieve, and a set of relevance judgments about those resources for each topic. GeoCLEF (http:// www.uni-hildesheim.de/geoclef/) is an example of
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a benchmark for Geographical IR (GIR) system evaluation. It is based on CLEF (http://www. clef-campaign.org/) and it has the aim to provide a framework for evaluation of systems with search tasks involving both spatial and multilingual aspects. Its importance is given by the large collection of topics and documents, but its focus is on users with geographical related tasks, not really on mobile user, in mobile environments. Within the CAR field, a benchmark evaluation named MREC (MoBe Retrieval Evaluation Collection) (Mizzaro, 2008) has been proposed to evaluate MoBe (Bulfoni, 2008) a framework for CAR of mobile applications. Although it is usually considered the most appropriate for CAR applications, the user evaluation approach has also some, not negligible, drawbacks, when compared with benchmarks. First it is an
Evaluating the Context Aware Browser
Figure 3. A (part of a) context descriptor
high level evaluation, where the primary interest is to study how the system satisfies the user’s needs, rather than on how the system serves the information needs of its users. Benchmark evaluations, on the contrary, are system centered: they directly focus on the evaluation of implementation details, and they can evaluate different aspect of the retrieval process. Second a mature prototype to test has to be available, complete of an effective user interface. This contrasts with the purposes of developers, and it forces significant implementation decisions uncovered by evaluations. Moreover user evaluation is more complex to perform, requires much more time than benchmarks, and it is more dependent on users’ subjectivity.
EXPERIMENTAL EVALUATION Although CAB application development is in an advanced phase, its retrieval mechanism needs a more accurate implementation. An early evaluation of the strategies we would like to implement is needed, so, considering the successful approach of MREC and the useful insights obtained, we adopted again a TREC-like benchmark evaluation, named CREC (CAB Retrieval Evaluation Collec-
tion). CREC focuses on the retrieval of Web pages and starts from the results obtained with MREC. We were interested in the following questions: how to build in an automatic way the queries to be sent to the external engine? Which is the best strategy in terms of effectiveness? How does the retrieval effectiveness change on the basis of the increase/decrease of the number of terms in the query, or of different kinds of terms exploited in the query? How effective is an automatic query formulation compared to a user manual search?
CREC: An Incremental Benchmark CREC is constituted by the usual TREC three components: the statements of information needs, a collection of documents, and a set of relevance judgments. The statements of information needs are defined by context descriptors, which represent different examples of user’s contexts in different domains (Figure 3). CREC includes 10 context descriptors, which differ for user activities, location, time, etc.; they have been designed similarly to TREC topics. A unique judge using a four level relevance scale made the relevance judgments: relevant, partially relevant, not classified, or not relevant.
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The
and fields in the context descriptor helped the judgments. The documents collection consisted of Web pages. Due to the evolving behavior of the Web (pages are dynamically added, removed, or modified), we opted for a dynamic collection evolving during the tests. Moreover, and more importantly, if a new implementation of the CAB external search engine needs to be evaluated, CREC will not contain, in general, all the retrieved pages. Since this would make the evaluation not reliable, in our approach the collection is not static: newly retrieved documents, and their judgments extend the collection. We have built two CREC versions so far. The first version was constructed performing 5 manual queries for each context descriptor, and judging the first 150 single retrieved documents for each context descriptor. Starting from this version of the collection, we adopted an “interactive search and judge” (Cormack, 1998) approach to add more relevant documents. In particular, we ran some queries, automatically built from context descriptors and, for each query, the Web pages that were not already in the collection and were retrieved in the first 10 ranks were added to the collection and judged. This second version of the collection had 3634 total pages: 494 relevant, 596 partially relevant, 34 not classified, and 2510 not relevant. Contrary to a real setting where the number of relevant documents is much lower than the number of documents in the collection, CREC collection had a high number of relevant documents because we searched for relevant documents. This is not a problem since we assume that unjudged documents are not relevant. Moreover we are not interested in all the documents, but just in the first retrieved ones.
Strategies We used CREC to compare four automatic query construction strategies. All of them work on lists of terms extracted automatically from the field
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Figure 4. The four strategies and a representation of how they combine the term indexes
<description> of the context descriptor (conversely, the human relevance judge uses the whole context descriptor): for instance, the strategies see the context descriptor in Figure 3 as: “user just landed london heathrow international airport looking flight timetable timetable connections london lunch time”. The strategies are based on two main indexes: tf.idf and geoterms (i.e., terms that refer to geographical information - a term is a geoterm if its Wikipedia page contains geographical coordinates). We chose tf.idf, because it is a classical and largely used IR technique, and geoterms because location is probably the contextual dimension that is more informative of user’s current context. These indexes, differently combined, are used to rank the lists of terms according to their importance in each strategy. The four strategies are (Figure 4): 1. tf.idf: all the significant terms in a context descriptor are taken into account for query
Evaluating the Context Aware Browser
Figure 5. nDCG@10 for the five strategies on all contexts
formulation based on the evaluation of their tf.idf value, in descending order. 2. inverse tf.idf: the previous strategy with terms taken in ascending order. This strategy represents a lower bound to use in the comparisons. 3. geoterms + tf.idf: the query exploits first the geoterms and then the remaining terms ordered by their tf.idf value, in descending order. 4. tf.idf + geoterms: similar to the previous strategy, but at first two terms with the highest tf.idf are introduced, then the geoterms, and then again the following tf.idf terms in descending order. The strategies have been implemented in Java using Yahoo! as external search engine through the API provided (http://developer.yahoo.com/ search/web/).
Results For each strategy and context descriptor, 10 queries of different lengths (from 1 to 10 terms) were automatically formulated, incrementally selecting
the first 10 terms of the ranked lists. Thus our query construction is incremental: once a term is in a query, it will remain in longer queries as well. We measured strategies’ effectiveness by means of a standard IR metric, [email protected] emphasizes quality at the top of the ranked list, and takes into consideration the first 10 retrieved items, which is reasonable for CAB, since the user is unlikely to scroll long lists of retrieved items. The manual approach, where users autonomously define their queries, was our upper reference strategy. In particular, for each context descriptor, a human operator has defined 5 queries. Figure 5 compares the four strategies, with the manual one, showing their effectiveness (nDCG@10, on the Y axis) averaged on all 10 contexts, for different query lengths (on the X axis). We notice four main aspects: 1. all the proposed strategies have lower performances than the manual one; 2. apart from the manual one, the most effective strategy is the geo + tf.idf; 3. in general, the performance of long queries is very low. This is probably because CREC contexts are made up by more than one
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Figure 6. Comparison of manual and geo + tf.idf approach on four contexts
facet (for example different activities), and their descriptors contain terms that relate to these facets. Thus increasing the number of terms in the query, it is more probable to have terms related to different facets, and this could decrease the performance; 4. the manual strategy has a different behavior: its performance tends to increase with query length. If performed by a human, a search session could improve with query refinements that add or change terms on the basis of the knowledge acquired by visualizing results. This is not performed by automatic strategies that construct the query incrementally. This is probably one of the reasons why manual strategy has a performance improvement the more terms are used. Figure 6 shows the comparison of the best automatic strategy and the manual one for four
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different contexts. We learnt that there was not a stable relationship between the two strategies: in some cases the manual had better effectiveness, in some other had worst effectiveness. In general however there is a clear margin to improve automatic approaches to query construction. Different context descriptors involved a different number of geoterms. Thus, to have a uniform view based on the number of geoterms adopted in the queries, we performed more analysis on the geoterms based strategies. The average results among all contexts are shown in Figure 7; in the graphics both the average, min, max values and the variance are shown. For the geoterms + tf.idf approach, the results increased adding the term with the highest tf.idf value after the geoterms, both with only 1 or 2 geoterms. The same is for the tf.idf + geoterms approach. The difference was that in this strategy, we had low performances using only the first 2 terms with highest
Evaluating the Context Aware Browser
Figure 7. Detailed results for the strategies with different number of geoterms
tf.idf value. Thus, from the results presented, we have understood that terms related to locations were more significant in a query, than the terms ordered based on their tf.idf value. In particular, the maximum performance was obtained adding one tf.idf term after all the geoterms. Moreover we noticed that there was no relationship between geoterms and their value in the tf.idf ordered list: in some cases geoterms have a high tf.idf value, in some other a very low one.
DISCUSSION Benchmark Reliability As a unique judge made the relevance judgments, to verify that subjectivity is not an issue for our benchmark, we performed an additional experiment, involving two more judges. We measured inter-judge agreement on a pool of retrieved pages,
and judgments agreed on average on 65% pages (which became 92% after a discussion between judges). Moreover we used the ADM measure (Della Mea, 2004) to better understand the different judgments. The values in the relevance scale, relevant, partially relevant, not classified, and not relevant, correspond respectively to the values 1, 0.5, 0.25, and 0. We obtained ADM values of 0.757 and 0.846 before the discussion, and 0.950 and 0.981 after the discussion. Figure 8 offers a graphic representation: the primary judge is presented on the X axis and a secondary judge (J1) is on the Y axis; the figure on the left is before the discussion between judges, the one on the right is after the discussion. To understand how our approach to collection construction copes with Web dynamics, we performed another experiment. The two secondary judges manually formulated 3 queries, in relation to a given context descriptor. Then we counted
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Figure 8. ADM values for the experiment involving the first secondary judge
the pages retrieved by the secondary judges but not retrieved by the automatically constructed queries, and among them the relevant pages. J1 retrieved 63 new never judged pages (21 relevant), while J2 retrieved 56 (34 relevant). This shows that new pages have appeared on the Web at a fast pace or, more probably, the initial collection was not complete. The new retrieved pages were also added to the collection, and the effectiveness evaluation was performed again. The dashed line in Figure 5 shows the effectiveness of geo + tf.idf computed considering the new pages and judgments: it does not change significantly. From the results CREC seems complete and reliable at least to a reasonable extent, and for its aims.
Benchmark Extensibility Like the Web, also our collection is in continuous evolution, thus we performed an additional experiment to understand the effort necessary to extend it. On the basis of a context descriptor not used in the benchmark reliability experiments, two judges
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(J and a new J3) are taken to build a manual query and then evaluate the retrieved pages (36 pages for person were evaluated). While J3 had never done this experiment before, J is an expert of both the domain, as he was the designer of the contexts descriptors, and of the evaluation procedure, as he already judged pages and he is used to the 4 level relevance scale adopted. The average time needed for the evaluation of one page is 48.9 seconds for J and 62.6s for J3, with a standard deviation of 14.3s for J and 32.3s for J3. The expert then used about 75% of the time needed by the not expert to perform the new judgments. Since the average time to evaluate a page is 55.7s, and since there are 2405 different pages from the first to the second version of our collection, the time to increase the collection was about 37 hours.
LESSONS LEARNED From this research we learned several kinds of lessons. Concerning the CAB development process, the CREC benchmark gave good insights
Evaluating the Context Aware Browser
(e.g., in the best strategy, the best performance appears just adding a term after the “geoterms”) and underlined weak points (e.g., adding more and more terms in the query does not increase performance). A more general outcome concerns the evaluation procedure. We understood that our approach is useful as it can simplify the user testing evaluation. For example, knowing which is the best strategy allows us to give to users one prototype, instead of different prototypes, one for each strategy. Moreover, once the benchmark is configured, it can be reused to test new strategies or related features, in a semi-automatic way (new judgments are needed but the update time is reasonable). Our approach seems interesting and valid for IR applications that need high precision, like CAB (for which nDCG@10 is an adequate metric). However, with high recall, the effort for the new judgments would probably be too high. A third general consideration concerns the relationship between relevance and usefulness in the context-aware retrieval field. In this work the information need gathered from the user’s context is adopted as reference point to judge the Web pages in the collection. In classical IR, we considered a page relevant if it provides an answer to the user’s information need. However, contextual information compounds the overall situation: taking into consideration the context, a page could be relevant for the user, but at the same time not useful. A page with too much information, and thus difficult to read on a mobile device, is not useful for the context, even if it is relevant to the user’s information need. In the same way we can consider a tourist in a town never visited before, without a means of transport, and looking for a tapas (variety of snacks in Spanish cuisine) bar in a rainy day. The system answers to the user query with the page of a tapas bar 10 minutes away, and with a map that guides the user to the destination. These results are highly relevant, but at the same time they could be useless: considering the overall situation in a rainy
day, a ten minutes walk could be unacceptable for a user. From this point of view, a page not useful has still to be considered relevant? The problem here is that in the context-aware retrieval field user’s information needs are not the only element to be considered for relevance: the contextual information represents constraints that can alter the relevance of a document. In particular, contextual values can modify both what the user needs and how the user needs it. The fourth kind of lesson we learned is related to the measures used to estimate the importance of terms related to context. For some experiment we exploited the tf.idf measure and at the beginning it seemed to be a good choice. However, we discovered that it is too much dependent on the context descriptor and, if the contexts were represented and described in a different way, we could have obtained very different tf.idf values. Thus tf.idf and all measures based on terms frequency in context descriptor could not be the proper solution. Moreover, other problems appear when we have to calculate tf.idf values, not in experimental condition, but at runtime, in a real situation. While tf values can be computed directly from the user context descriptor, which are the other contexts (documents) we exploit to compute the idf value? The history of previous contexts? Or other users’ contexts? Differently from documents, that are rigidly separated from each other, contexts cannot be easily identified as they are not “watertight compartments” but they continuously flow in each other.
CONCLUSION In this paper we have presented our approach for the evaluation of a CAR application for the mobile environment. We evaluated different strategies for automatic query building based on users’ current context. Despite user testing is the main evaluation technique adopted in this field, the early stage of development of our system and
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the need of measuring the effectiveness of different strategies guided us toward a TREC-like benchmark approach. In this way, we have made our second step to refine a methodology whose aim is to become a general early stage evaluation technique for retrieval processes in context-aware systems. On the basis of our experience, we believe that early stage benchmark evaluations followed by user studies, are an effective methodology to evaluate systems like CAB. The benchmark, in fact, does not substitute the user testing evaluation. Rather, several early stage benchmark experiments could provide more solid basis for the subsequent user testing that can thus be more focused. In the future we will work on two issues: to seek for more effective strategies that better compete with the manual one (e.g., removing the constraint of incremental query construction) and, more generally, to better understand reliability and usefulness of our incremental benchmark approach. It would be also interesting to work towards a publicly available or open source context test collection, containing a set of context descriptors (perhaps with a representation different from TREC topics, and maybe including a temporal longitudinal component as well, e.g., using Schank and Abelson’s scripts), Web resources, and relevance judgments. Finally we plan to execute the experiments in a fully mobile environment and to study how relevance judgments and results change switching from a desktop to a mobile environment.
ACKNOWLEDGMENT The authors acknowledge the financial support of the Italian Ministry of Education, University and Research (MIUR) within the FIRB project number RBIN04M8S8, and the region Friuli Venezia Giulia.
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REFERENCES Brown, P. J., & Jones, G. J. F. (2001). Contextaware retrieval: Exploring a new environment for information retrieval and information filtering. Personal and Ubiquitous Computing, 5(4), 253–263. doi:10.1007/s007790170004 Bulfoni, A., Coppola, P., Della Mea, V., Di Gaspero, L., Mischis, D., Mizzaro, S., et al. (2008). AI on the move: Exploiting AI techniques for context inference on mobile devices. In Proc. of 5th Prestigious Applications of Intelligent Systems (PAIS 2008), co-located with ECAI08 (pp. 668–672). IOS Press. Carter, S., & Mankoff, J. (2004). Challenges for Ubicomp Evaluation. Technical Report UCBCSD-04-1331, Computer Science Division, University of California, Berkeley. Coppola, P., Lomuscio, R., Mizzaro, S., Nazzi, E., & Vassena, L. (2008). Mobile social software for cultural heritage: A reference model. In 2nd Workshop on Social Aspects of the Web (pp. 69–80). Cormack, G. V., Palmer, C. R., & Clarke, C. L. A. (1998). Efficient construction of large test collections. In SIGIR ’98: Proceedings of the 21st annual international ACM SIGIR conference on Research and development in information retrieval (pp. 282–289). ACM. Della Mea, V., & Mizzaro, S. (2004). Measuring retrieval effectiveness: A new proposal and a first experimental validation. Journal of the American Society for Information Science and Technology, 55(6), 530–543. doi:10.1002/asi.10408 Göker, A., & Myrhaug, H. (2008). Evaluation of a mobile information system in context. Information Processing & Management, 44(1), 39–65. doi:10.1016/j.ipm.2007.03.011
Evaluating the Context Aware Browser
Harper, D. J., & Hendry, D. G. (1997). Evaluation light. In M. Dunlop (ed.), Proc. of the second MIRA workshop (pp. 53–56). Technical Report TR-1997-2, Department of Computing Science, University of Glasgow, Glasgow. Jones, G. J. F., & Brown, P. J. (2004). Contextaware retrieval for ubiquitous computing environments. In: Mobile HCI Workshop on Mobile and Ubiquitous Information Access (pp. 227–243). Volume 2954. Springer LNCS. Mizzaro, S. Nazzi, & E., Vassena, L. (2008). Retrieval of context-aware applications on mobile devices: how to evaluate? In Proc. of Information Interaction in Context (IIiX ’08) (pp. 65–71). ACM. Scholtz, J. (2001). Evaluation methods for ubiquitous computing. Ubicomp Workshop. Scholtz, J. (2006). Metrics for evaluating human information interaction systems. Interacting with Computers, 18, 507–527. doi:10.1016/j. intcom.2005.10.004 Scholtz, J., & Consolvo, S. (2004). Towards a discipline for evaluating ubiquitous computing applications. Technical Report IRS-TR-04-004. Weiser, M. (1991). The computer for the 21st century. Scientific American, 265(3), 94–104. doi:10.1038/scientificamerican0991-94
KEY TERMS AND DEFINITIONS Mobile Devices: a mobile device (also known as cellphone device, handheld device, handheld computer) is a pocket-sized computing device. Information Retrieval: is the science of searching for documents, for information within documents. Context-Awareness: refers to the idea that computers can both sense, and react based on their environment, and based on the situation they are used in. Context Aware Browser: general-purpose solution to Web content fruition by means of context-aware mobile devices. Proactive: controlling a situation by causing something to happen rather than waiting to respond to it after it happens Evaluation: action of determining how a particular system behaves using criteria against a set of standards Benchmark: in IR a benchmark is composed by a collection of topics (expressions of user’s information needs), a collection of resources to retrieve, and a set of relevance judgments about those resources for each topic. It is a kind of evaluation that aims at measuring performances of systems in a controlled environment.
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Chapter 2
Routing in Wireless Ad Hoc and Sensor Networks Milos Stojmenovic University of Ottawa, Canada
ABSTRACT Routing is the process of finding a path from a source node to a destination node. Since each node has a limited transmission range, the message is normally forwarded by other nodes in an ad hoc or sensor network. Therefore routes normally consist of several hops. Proposed routing schemes can be divided into topological and position based, depending on the availability of geographic location for nodes. Topological routing may be proactive or reactive. Position based routing consists of greedy approaches applied when a neighbor closer to the destination (than the node currently holding the packet) exists, and recovery schemes otherwise. In order to preserve bandwidth and power which are critical resources in ad hoc and sensor networks, localized approaches are proposed, where each node acts based solely on the location of itself, its neighbors, and the destination. There are various measures of optimality which lead to various schemes which optimize hop count, power, network lifetime, delay, or other metrics. A uniform solution based on ratio of cost and progress is described here
INTRODUCTION Routing is the process of finding a path from a source node to a destination node. Since each node DOI: 10.4018/978-1-60960-042-6.ch002
has a limited transmission range, the message is normally forwarded by other nodes in an ad hoc or sensor network. Therefore routes normally consist of several hops. Proposed routing schemes can be divided into topological and position based, depending on the availability of geographic
Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.
Routing in Wireless Ad Hoc and Sensor Networks
location for nodes. Topological routing may be proactive, reactive or hybrid. Position based routing consists of greedy approaches applied when a neighbor closer to the destination (than the node currently holding the packet) exists, and recovery schemes otherwise. In order to preserve bandwidth and power which are critical resources in ad hoc and sensor networks, localized approaches are proposed, where each node acts based solely on the location of itself, its neighbors, and the destination. There are various measures of optimality which lead to various schemes which optimize hop count, power, network lifetime, delay, or other metrics. A uniform solution based on ratio of cost and progress is described here. An ad hoc network is a set of interconnected nodes that are deterministically or randomly dispersed in a given area and communicate over a wireless medium. Each of these nodes has the ability to send and receive messages to and from other nodes. Connections are possible over multiple nodes (multihop ad hoc network). Typical examples of ad hoc networks are conference and disaster relief networks. Sensor networks are similar to ad hoc networks in the sense that nodes have the ability to communicate over a wireless medium, but they differ in purpose and communication patterns. Each node in a sensor network is a small, battery powered device that has the capability of measuring or tracking the environment. Sensors can measure distance, speed, humidity, temperature, light, motion, seismic data, torque, and a host of other quantitatively measurable attributes of the environment that they are located in. They differ from ad hoc networks in purpose since each sensor has a specialized purpose of measuring and reporting the measured data. The two types of networks also differ in communication patterns. The nodes in ad hoc networks usually communicate between each other where the source and destination can be any two nodes. In sensor networks, nodes typically only communicate with a base station or sink. They usually only need to report data,
and are not able to perform a certain action based on the collected data, other than transmitting or receiving messages. Therefore, communication in a sensor network is much more structured than in an ad hoc network. Nodes in ad hoc or sensor networks may or may not know their geographic positions. The availability of positional information depends on the hardware of the nodes in the network. Typical devices used for positional information are GPS locators which are relatively small. Positional information is essential in sensor networks. Sensors need to know where they are located in order for whatever they are measuring to make sense to the base station. If a sensor detects fire, for instance, it must report the location of the fire, or else an appropriate response is not possible. However, sensors can be easily equipped with GPS locators, and the sensors themselves are relatively small devices. Positional information of sensors is not an easy problem (Bachrach & Taylor, 2005), but it is definitely an important part of a sensor’s makeup. It is assumed that nodes have equal transmission radii R, where two nodes are neighbors if they are located at most R units away from each other. That is, two nodes can directly communicate if and only if the distance between them is ≤R. This is referred to as the unit disk graph model. The wireless communication medium is different from the wired one. The wired medium normally provides only one-to-one communication, meaning that a message sent to a neighbor is only received by that neighbor. However, the wireless medium enables one-to-all communication, where a message sent by one node is received by all of its neighbors. This provides both advantages and limitations. A single message reaches more nodes; however, at the same time, bandwidth is limited because normally all nodes use the same frequency for communication. Sensors also have a sensing radius, which is normally less than the communication radius.
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Presented protocols are applicable to both ad hoc and sensor networks, with different efficiencies, depending on the network assumptions. The availability of position information and mobility of the destination determines the choice of the corresponding class of protocols. Relative mobility impacts the suitability of protocols. For static nodes, proactive approaches are efficient, while for mobile nodes, reactive ones work better. Changes from active to sleep status at individual nodes also make certain protocols more efficient compared to others.
Routing without Position Information Routing without positional information is more difficult than routing with positional information, and requires more overhead in wireless networks. There are two general methodologies that could be used to route messages if position information is not available: proactive routing, and reactive routing. Proactive routing means that routes must be established before messages are sent through the network. This involves storing routing tables at each node in the network that act as roadmaps for routing. Routing tables are very cumbersome from a memory point of view and costly in the case of mobile nodes. Proactive routing with highly mobile nodes is very impractical since frequent routing table updates are necessary for the scheme to work. It is practical in situations where nodes are mostly static, such as in the case of a conference. Reactive routing is a more practical solution to networks with mobile nodes. Using this routing framework, nodes that need to send a message first need to find the destination node by flooding the network with a route discovery message. The destination node would then reply to the source using the memorized hops through the network. This type of routing is used in ad hoc networks where the network composition is variable. It could also be used in certain scenarios in sensor networks where nodes could turn themselves off
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to conserve energy. New routes would then have to be found.
Routing with Position Information Positional information is helpful for routing in ad hoc networks because it is possible to find a route between two nodes without flooding and without routing tables. In both the cases of sensor networks and ad hoc networks, knowing the positions of nodes facilitates localized routing. Localized routing is a phrase that means routing just by knowing local information. A node that needs to send a message to another node knows its own position, the positions of all of its neighbors, and the position of the destination. Assuming this information is available, simple greedy localized routing protocols exist, which are competitive to the shortest path algorithm for dense networks. There also exist intelligent localized routing algorithms (Bose & Al, 2001), which guaranty delivery of the message to the destination in connected unit disk graphs, without using any memorization at nodes. Localized routing has considerably lower communication overhead compared to approaches using global network information, in networks with mobile nodes, or nodes that change their status between active and sleeping. The main advantage is in the cost of updating the needed network information. Updating information for localized routing is simple: each node periodically transmits a ‘hello’ message, received by all its neighbors. Other approaches require propagating topological changes throughout the network or the exchange of large messages containing routing tables. There must exist node location service mechanisms in ad hoc networks since destination nodes may move, or simply turn themselves off, whereas the location of a sink or base station is normally fixed and known to sensors in sensor networks. This may affect the route of a potential message, and more severely impact the power and bandwidth consumption of nodes due to excess
Routing in Wireless Ad Hoc and Sensor Networks
communications. The topic of location updates in mobile ad hoc networks is covered in greater detail in (Stojmenovic, 2006). Estimating hop counts between nodes is discussed in (Contla & Stojmenovic, 2003).
TOPOLOGICAL ROUTING Topological routing refers to routing where positional information is not used. We now describe two basic types of topological routing: proactive and reactive.
Proactive Routing A typical example of a proactive routing algorithm is the Bellman-Ford scheme (Jubin & Tornow, 1987). In this framework, each node exchanges its routing table with all of its neighbors and updates its own routing table if better routes to some destinations are available based on the new data. The entries in the routing table for one node are the costs of sending messages from that node to all other nodes using the best know routes. These entries also contain the next forwarding node to send the message to for all known nodes. Routing table exchanges of information are done periodically, so new routes become known gradually, as several iterations of the table exchange step are performed. This protocol is a popular one on the Internet, since most of the nodes are not mobile. In a highly mobile environment, table exchanges would have to be more frequent, which results in high overhead, and an impractical solution. To illustrate the Bellman-Ford technique, we imagine that a source node S has 3 neighbors, and intends to send a message to destination D. We also assume that the table exchanging step is about to be performed. When node S exchanges its routing table with its neighbors, it analyzes which neighbor to send the message to. In the received routing tables, information is listed about the costs of sending a message from that node to node D.
Node S then forwards the message to the node F that minimizes the cost of link S to F plus the cost of sending from F to the destination. Another way to obtain the shortest possible routes between any two pairs of nodes is to run Dijkstra’s shortest path algorithm for every pair of nodes in the network (McQuillan & Al, 1980). However, all link and node (topological) changes need to be broadcasted in the network. All nodes then maintain global network information, and are able to make optimal decisions when routing is in progress. Some optimizations are proposed in (Jacquet & Al, 2001), in the form of OLSR (optimized link state routing) protocol. Topological changes are normally broadcasted to all nodes via flooding, where each receiving node will retransmit the message exactly once. OLSR (Jacquet & Al, 2001) limits the retransmissions to certain nodes, which together create a backbone (any node not in the backbone is a direct neighbor to at least one node from the backbone). The specific protocol used, which reduces message flooding, is called Multi Point Relay MPR. Each transmitting node includes the list of neighbors that are asked to retransmit the message in the packet. The selection is made so that all 2-hop neighbors (neighbors of neighbors) are ‘covered’, that is, receive the message only if the selected neighbors retransmit. When a message is received at a node, it simply checks whether it is ‘asked’ to retransmit it or not, and behaves accordingly (Jacquet & Al, 2001). This reduces the flooding driven effects of wasted retransmissions of the original message.
Reactive Routing This type of routing is analogous to tourists trying to find an obscure address in a new city: they get closer and closer to the destination by asking people along the way. There are two variants of reactive routing strategies that we will examine here. They work very similarly, and can almost be considered as extensions of one another. One
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Figure 1. Route discovery
Figure 2. Destination reports back
variant of route discovery is called the Advanced On-demand Distance Vector AODV (Perkins & Royer, 2002), and the other is Dynamic Source Routing DSR (Johnson & Maltz, 1996). The main idea here is that a source node first has to find the destination node before it can start sending messages. Therefore, it floods a route discovery message throughout the entire network. Each node retransmits the packet exactly once, upon the first receipt of it. We turn our attention to Figure 1 to illustrate this procedure. Node S starts flooding the network by passing the route discovery message to all of its neighboring nodes. The flooding is continued as outlined by the green arrows in the same figure. Note that messages are not retransmitted more than once since subsequent copies of the same message are ignored. Flooding is continued as depicted by the dark red and dark blue arrows until the destination is reached. For clarity, retransmissions by nodes that do not reach any node for the first time are not drawn. The route that is uncovered is transmitted back to the source in the reverse order of its discovery, as seen in Figure 2. In the AODV scheme, each node in the path would memorize the next hop back to the source. Thus A records S, B records A, C records B and D records C, which enables D to report to S via C, B and A (see Figure 2). In the DSR variant, the route discovery packet carries the whole paths from the source; therefore, destination D receives the memorized path SABCD. The source would be notified of the entire path to the destination.
After discovering and memorizing the route, S uses it to send actual traffic to D. Messages could now be sent using either hop by hop or total path variants. The described reactive routing algorithm is a basis for several existing protocols applied in specific scenarios. For example, ‘directed diffusion’ (Intanagonwiwat & Al, 2000) is a highly cited routing protocol for sensor networks, applying a ‘data centric’ approach. The data sink identifies a set of attributes and propagates an interest message throughout the network. The interest is flooded blindly. Each receiving node records the interest and establishes a so called gradient, which is simply a link toward a neighbor on a route back to the sink. The protocol is thus algorithmically equivalent to route discovery where the search for an IP address has been replaced with search for data of interest located in some sensors, which have no identities. AODV (Perkins & Royer, 2002) and DSR (Johnson & Maltz, 1996) use the hop count metric (the number of transmissions) as the measure of optimality of a route. The route discovery message might contain several other cost measures which may be taken into consideration while choosing the best path. Depending on the application, cost measures might include delay, congestion or power consumption. Several paths might be available, but the best one is chosen at the destination. Applications in which delay is paramount, such as QoS, may require the usage of several paths to the destination to increase bandwidth. The opti-
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mal route from source to destination, measured by a particular metric, may not be the first one that reaches the destination. The route discovery process is therefore modified. When a route discovery packet originating from S is received by node A for the first time, the total cost (on a partial route from S to A) is recorded. Each new route request packet for the same source-destination pair arrives with its new total cost. If that cost is lower than the previously recorded cost, the route request is retransmitted, with that new total cost being appended to the message. Otherwise this message is ignored. A technique for reducing the cost of flooding is an expanding ring search. In this procedure, the source node would send out a route discovery message to its neighboring nodes with an attached time to live TTL variable. This TTL variable is used in determining how many links the route discovery message is permitted to cross from the source node. For instance, the TTL can be set at 2 hops initially to limit the search radius of the initial route discovery message. The idea is that the destination might be near or far away from the source. Instead of flooding the network right away, we try to find the destination among the nodes that are close to the source. If the destination node is not found, then the TTL variable is increased (e.g. doubled), and the radius of the search expands. These expanding ring search phases are repeated until the destination is found. Figure 3 shows a sample network with source and destination nodes labeled as S and D respectively. The purple ellipse marks the area that the route discovery message with TTL 2 would search. The destination is not found in this area, and the TTL is doubled. The aqua green area is searched with a TTL of 4. The destination would be discovered in the next search phase where the TTL is 8.
Hybrid Routing Proactive and reactive routing approaches can be combined into a single approach. Proactive rout-
Figure 3. Expanded ring search strategy
ing is applied if the destination is nearby, while reactive routing is applied when it is far away. For instance, in the ZRP (Zone Routing Protocol) (Beijar, 2002), a zone for a source includes all nodes up to k hops away. Routing information inside its zone is constantly updated. Proactively, whenever a link state is changed, a notice is sent k hops away by flooding. Therefore, the source always knows how to reach a destination that is at most k hops away. Routing to a destination that is not nearby (more than k hops away) is done by the reactive approach. A route discovery message is flooded in the network until a zone containing the destination is found. The border node of that zone then can report back to the source.
POSITION BASED ROUTING Advance Mode Routing In this section, we consider the situation where nodes are equipped with positional information. The positions of each node’s neighbors may be obtained by occasional exchanges of ‘hello’ messages.
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Cost to Progress Routing Framework We will now describe a general routing framework (Stojmenovic-2, 2006) which is applicable for a variety of cost metrics. It is understood here that each message sent between two nodes has an inherent cost associated with it, and a progress value. The cost of transmitting a message between two nodes can be defined in several ways. Typically, it falls under hop count, power consumption and delay. Progress measures the advancement of the message toward the destination. One way to measure progress is by considering the distance of the message to the destination. In Figure 4, we see a network with labeled nodes, and cost values at each edge. The red sequence of arrows is the shortest path from source S to destination D. We require global information about the network (locations of all nodes) in order to be able to find the shortest path. However, we are confined to local information. Therefore, node S has the option of forwarding the message to one of nodes F, I and K. It is proposed here that the cost of the next link should be compared to the progress made by forwarding it to that link. Therefore, values: 18/ (|SD|-|FD|), 15/(|SD|-|ID|), and 7/(|SD|-|KD|) are compared and the minimal value determines the next forwarding node in the chain. If such logic is followed, the purple sequence of arrows marks the resulting path the message takes from source to destination. Cost to progress ratio based routing was recently enhanced. Instead of sending directly to neighbor A with the optimal cost to progress ratio, source S constructs the shortest weighted path (with the considered cost as the weight) toward A, and the message is sent along that path until a node B that is closer to D than S is found. Note that intermediate nodes may recompute the path, so that the message remains of constant length. Node B then resumes the same protocol.
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Figure 4. Shortest weighted path and cost to progress ratio protocols
Greedy Routing and MFR Greedy routing in wireless networks was first proposed by Finn (Finn, 1987). In his work, it is understood that the cost metric of sending one message to a neighboring node is one hop. This is a special case of the cost to progress routing framework since it assumes that message sending costs between neighboring nodes are equal regardless of the distance between them. In order to illustrate this point, we observe the network in Figure 4 again. Since the cost of traversing an edge is now one, we can disregard the weights of the edges. Source S still needs to pick one of its neighbors (F, I, or K) to forward the message to. The greedy algorithm now only considers the progress made by forwarding the message to each of these nodes since transmission costs are now constant. By progress, we mean minimizing the distance from the next node to the destination. The algorithm therefore takes the minimum distance of FD, ID, and KD. It chooses I as the next node to forward the message to. The purple arrows again mark the path that the greedy algorithm would choose. A similar progress measure based on distance was proposed by (Takagi & Kleinrock, 1984) called Most Forward within Radius (MFR). Instead of choosing the next forwarding node as the one
Routing in Wireless Ad Hoc and Sensor Networks
which is minimally distanced from the destination, we take the one whose projection onto the line CD is closest to destination D, as seen in Figure 5. In this figure, node C is deciding where to forward the message intended for destination D. The projections of potential forwarding nodes F, A and G are seen as F’, A’ and G’ respectively. A’ is closest to the destination, and therefore, the message is forwarded to node A. This is loop free algorithm, although by no means a solution that guarantees delivery. Even though loops are not possible, reaching a dead end is, and recovery protocols will be discussed in section 3.2.
Power Aware Routing This form of localized routing was first studied in (Stojmenovic & Lin, 2001). It takes into consideration the power needed to transmit a message to the next node. The power needed to send a packet from C to A is proportional to rα+c, where α is a power attenuation factor (2≤α≤6), r=|CA| is the distance from node C to node A, while c is a constant greater than 0. Constant c accounts for the fixed energy costs of sending and receiving a message and running such an electronic circuit. Power aware routing is another example of localized routing. The algorithm will forward the message to the node A that minimizes the ratio of transmission energy to message progress (rα+c)/ (|CD|-|AD|) (Kuruvila & Al, 2006). One of the disadvantages of power aware routing (as with all of the other greedy algorithms we have seen so far) is that certain routes become popular, and soon the nodes along these routes become drained. It is therefore beneficial to consider a different routing strategy that takes into account the remaining energy of a possible forwarding node before nominating it to continue the routing task. In such cases, nodes have to announce their remaining energy status via periodic ‘hello’ messages. The details of localized power and remaining energy aware routing protocols
Figure 5. Selecting best neighbor in MFR routing protocol
are in (Stojmenovic & Lin, 2001), (Kuruvila & Al, 2006).
QoS Routing Qos routing is highly applicable to multimedia traffic such as on-demand video. In such cases, both time and bandwidth are critical aspects of routing. Routing protocols of this nature will become more popular as handheld portables become more advanced with the ability to access TV programming and other high bandwidth consumption applications. In this type of routing (He & Al, 2005), (Huang, Dai & Wu, 2004), (Stojmenovic-2, 2006), the factor we are interested in limiting is the time it takes to send a message from a source to a destination. We therefore have to consider a broader spectrum of factors that influence message passing. Specifically, we mean the delays experienced if a message is sent to a popular node. By delays, we mean queuing and the time it takes to forward the message. The criteria for selecting the next forwarding node A from current node C is based on minimizing the delay/(|CD|-|AD|).
Beaconless Routing So far, we have seen routing approaches where nodes have local knowledge about their neighbors. Local knowledge is made available by periodically
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Figure 6. Gabriel graph
sending ‘hello’ packets. However, this causes significant overhead, especially if the amount of actual traffic is not high. Furthermore, since nodes may move, or turn themselves off at any time, the information (position or even availability) assumed about neighbors may not be accurate. This leads to suboptimal routing procedures or even unnecessary failures. In such cases, Zorzi (Zorzi, 2004) proposes to have a dynamic neighbor discovery phase where RTS/CTS packets are sent before sending actual routing packets. A node which wishes to send a message first sends out an RTS (ready to send) packet. All receiving neighbors calculate a timeout waiting period, which corresponds to their distance from the destination. Neighbors closer to the destination select shorter timeouts. The neighbor closest to the destination is therefore the first one to respond with a CTS (clear to send) packet. Upon receiving the first response from a neighbor A, current node S transmits the actual message to A. Other neighbors overhear that message which cancels their own possible responses at the end of their timeouts.
Recovery Mode Routing It is possible for a routing algorithm to guarantee delivery of a message while only dealing with local information, and not applying any memorization at nodes (all necessary information arrives with the packet). This face algorithm (Bose & Al, 2001) only assumes that there exists a path from a source
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Figure 7. Marked source and destination
to a destination, and a unit disk graph. The face algorithm is a recovery scheme and is normally applied when the greedy algorithm fails. The details of face and the combined GFG (greedyface-greedy) algorithms are seen in this section.
Face Routing Face routing (Bose & Al, 2001) is an algorithm that guarantees delivery of a message, but does not always have the best performance when it comes to efficiency. This type of routing algorithm has two phases: the construction of a Gabriel graph from the network, and the actual routing phase. Gabriel graphs are planar, which means that no two edges intersect. Planar graphs are a composition of faces, along the sides of which messages can be passed. Figure 6 shows an example of a Gabriel graph of a network. There exists an edge between two nodes (a, b) in a Gabriel graph if and only if there are no nodes in the disk with diameter ab. In Figure 6, we see that there is an edge in the green circle, since there are no nodes in that area. Conversely, we see no edge in the purple circle since there are nodes in that area. In Figure 7, we have the Gabriel graph of the network in Figure 6, with marked source and destination nodes, S and D. There is also a purple imaginary dashed line from the source to the destination in Figure 7. In the face routing algorithm, this line is used to determine the points at which a message would change faces on its way to the destination. To illustrate this point, we
Routing in Wireless Ad Hoc and Sensor Networks
Figure 8. Face routing
Figure 9. Greedy mode in GFG routing
Figure 10. Face mode in GFG routing
Figure 11. Result of GFG routing
focus on Figure 8. Here, we see that the message follows the contours of each face until it hits the purple dashed line. At such points, it switches faces, and follows the contours of the next face. This procedure is repeated until the message reaches the destination. We can see from this illustration that face routing is not the most efficient algorithm, but nevertheless a useful one in cases where other greedy algorithms fail. We see such a case in the next section.
purple arrow. This node cannot forward the message to any node that is closer to the destination than itself. At this point, the greedy algorithm has failed, so face mode takes over since we know that face mode guarantees delivery of the message as long as there exists a path to the destination. The dashed line is drawn from that node to the destination, and face mode begins. It traverses the edges of the outer face until it finds a node that is closer to the destination than the node at which face mode began. When it finds such a node, as seen is Figure 10, we switch back to greedy mode and continue the routing process. Figure 11 shows the result of the GFG routing protocol, where the message was successfully delivered by the greedy phase in the last step. It was shown recently in (Frey & Stojmenovic, 2006) that face routing always recovers along the first traversed face if the Gabriel graph is used for planarization. However, in some cases, such as when a realistic physical layer is considered, other methods need to be applied to planarize the
GFG Routing Greedy Face Greedy (GFG) routing is a combination of greedy routing and face routing. The idea behind this algorithm is to proceed with the greedy algorithm until it becomes stuck, then to use the face mode to recover from such instances, and to again proceed with greedy mode. Figure 9 illustrates the GFG algorithm on a sample network. In greedy mode, node S forwards the message to the next node which is singled out by the
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graph, and face routing may have to traverse several faces. To guarantee delivery, GFG only needs the graph to be somehow planarized, independently of the method applied and the particular planar graph outcome.
Beaconless GFG In beaconless GFG, the nodes do not have knowledge of their neighbors. Therefore, at each step in forwarding a message, some local knowledge must be obtained. The node S currently holding the message would send out a single RTS packet as a single hop broadcast in which a bit would be added to signify whether the node wishes to send its message in greedy or face mode. In greedy mode, the neighboring node which is closest to the destination responds with a CTS packet after a time delay. The duration of the time delay is inversely proportional to the distance of that node to the destination. Therefore, the node that is closest to the destination transmits its CTS packets after a shorter time delay. This transmission cancels other CTS packets that are to be sent by other nodes. In face mode, an RTS packet is sent out, and neighbors that are closer to the node sending the RTS respond first with CTS packets. If a node A hears another closer neighbor B responding which is inside the circle with diameter AS, it indicates that AS is not in the Gabriel graph, and A then does not respond. Thus only the neighbors in Gabriel graph will respond. The Gabriel graph is then constructed from the received responses, and face routing continues. The details of this algorithm are found in (Chawla & Al, 2006).
ROUTING WITH A REALISTIC PHYSICAL LAYER The routing assumptions we have made so far state that two nodes are neighbors if they are at most distance R away from each other. If that condition is satisfied, then it was assumed until now that
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a message passed from two neighboring nodes had a 100% chance of arriving. Realistically, a message is received if the signal strength at the receiver is greater than a certain threshold, but signal strength has random variations. It is still true under realistic physical layer assumptions that neighbors can pass messages, but it is not always true that each message is received the first time it is sent. This is now a probabilistic function of distance. Figure 12 shows typical reception probabilities based on distance.
Route Discovery Process The route discovery process considering a realistic physical layer is not the same as when considering just the regular unit disk model. In a basic disk model of routing, one discovery message is enough for neighbors to correctly receive it and promptly respond. Therefore, neighbor and route discovery is relatively simple. In a realistic physical layer setting, messages requesting routes may not be received by other nodes, and might have to be rebroadcast. If only one discovery message is sent out, it might not be received by a node that is a relatively good connection to the intended destination. In this case, sub-optimal paths might be taken to the destination. On the contrary, it might also happen that a very weak connection to a distant node might be discovered by just one route discovery message. Under such circumstances, when actual messages try to use this link, they will fail most of the time. It is hence much better to send out multiple instances of route finding messages, and based on the available responses, construct a path that seems most reliable (Stojmenovic & Al, 2005). Route discovery packets are generally shorter than full message packets, and are received with a higher probability. Thus, more research is needed to design a route discovery process with low overhead, but which produces good routes in practice.
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Figure 12. Reception probability vs. distance
Position Based Routing with Realistic Physical Layer In any routing algorithm with a realistic physical layer, whether it be greedy or whether it has global information, the cost of passing a message from one node to the next needs to reflect the capability of efficient transmission. What we mean by this is that the cost of passing a message directly between two distant nodes is not the same as passing a message between two nodes that are relatively close to one another. Under realistic conditions, nodes have to assume that their message did not reach the intended receiver unless that receiver acknowledges receiving the message. In circumstances where neither the message reception nor the acknowledgement reception is certain, messages need to be retransmitted u times until an acknowledgement is received. Here, u is approximately 1/p(x), where p(x) is the packet reception probability for two nodes at distance
x. The cost of transmitting a message between two nodes can now be measured in expected hops, where a number of hops might be necessary to send a message to a neighboring node. This new cost function is called the expected hop count (EHC). Essentially, all of the connections, or edges, in a network become associated with weights. Greedy and other routing schemes now must consider the quality of links, and account for them by minimizing EHC(CA)/(|CD|-|AD|), where C and A are neighboring nodes (Kuruvila & Al, 2006). A localized routing algorithm with a realistic physical layer that guarantees delivery is described in (Nayak & Stojmenovic, 2006). It is based on the GFG algorithm where greedy mode is as described above, while face mode uses the same path as in the face routing scheme (Bose & Al, 2001)
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CONCLUSION We have seen here a number of approaches of routing in ad hoc and sensor networks. Certain routing methodologies are better suited for sensor networks, while others are better suited for ad hoc networks. There are a number of factors that influence the way routing algorithms should be designed and yet still even more that influence the way that the algorithms actually work in both scenarios. We have to take into consideration that most of this work is highly theoretical, and that a fully functioning sensor network that solves a particular problem is yet to be assembled. Routing algorithms that consider local information yet guarantee delivery of messages seem most promising for large scale networks. Power aware routing seems like a good cost function for wireless networks where power consumption is the main issue. QoS routing is a logical approach for high bandwidth demand applications such as on demand video. Each routing protocol that we have seen here has its application in certain scenarios. Further development of this field, and incorporation and testing of these algorithms may result in even more efficient and productive routing strategies.
REFERENCES Bachrach, J., & Taylor, C. (2005). Localization in Sensor Networks. Handbook of Sensor Networks. New York: Wiley-Interscience. Beijar, N. (2002). Zone Routing Protocol (ZRP), Licentiate course on Telecommunications Technology. Ad Hoc Networking. Bose, P., Morin, P., Stojmenovic, I., & Urrutia, J. (2001). Routing with guaranteed delivery in ad hoc wireless networks. ACM Wireless Networks, 7(6), 609–616. doi:10.1023/A:1012319418150
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Chawla, M., Goel, N., Kalaichelvan, K., Nayak, A., & Stojmenovic, I. (2006). Beaconless positionbased routing with guaranteed delivery for wireless ad hoc and sensor networks. International Journal of Sensor Networks, 1(1), 61–70. Contla, P., & Stojmenovic, M. (2003) Estimating Hop Counts in Position Based Routing Schemes for Ad Hoc Networks. Telecommunications Systems (Kluwer/Springer), 22(1-4), 109-118. Finn, G. G. (1987). Routing and addressing problems in large metropolitan-scale internetworks. ISI Research Report ISU/RR-87-180. Frey, H., & Stojmenovic, I. (2005). Geographic and energy aware routing in sensor networks. Handbook of Sensor Networks: Algorithms and Architectures. New York: Wiley. Frey, H., & Stojmenovic, I. (2006). On Delivery Guarantees of Face and Combined Greedy-Face Routing Algorithms in Ad Hoc and Sensor Networks. In Proceedings of the The Twelfth ACM Annual International Conference on Mobile Computing and Networking MOBICOM, Los Angeles. He, T., Stankovic, J., Lu, C., & Abdelzaher, T. (2005). A Spatiotemporal Communication Protocol for Wireless Sensor Networks, IEEE ICDCS, May 2003. IEEE Transactions on Parallel and Distributed Systems, 16(10), 995–1006. doi:10.1109/TPDS.2005.116 Huang, C. Dai, F., & Wu, J. (2004). On-demand location-aided QoS routing in ad hoc networks. In Proc. Int. Conf. Parallel Processing ICPP, Montreal, 502–509. Intanagonwiwat, C., Govindan, R., & Estrin, D. (2000). Directed diffusion: a scalable and robust communication paradigm for sensor networks. In Proceedings of the ACM/IEEE International Conference on Mobile Computing and Networking, Boston, MA, pp. 56-67.
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Jacquet, P., & Muhlethaler, P. Clausen, T., Laouiti, A., Qayyum, A., & Viennot, L. (2001). Optimized link state routing protocols for ad hoc networks. In Proc. IEEE Int. Multi-Topic Conf. INMIC, Lahore, Pakistan, pp. 62-68. Johnson, D. B., & Maltz, D. A. (1996). Dynamic source routing in ad hoc wireless networks. In Imielinski, T., & Korth, H. F. (Eds.), Mobile Computing (pp. 153–181). Kluwer. doi:10.1007/9780-585-29603-6_5 Jubin, J., & Tornow, J. D. (1987). The DARPA packet radio network protocols. Proceedings of the IEEE, 75(1), 21–32. doi:10.1109/ PROC.1987.13702 Kuruvila, J., Nayak, A., & Stojmenovic, I. (2006). Progress and location based localized power aware routing for ad hoc and sensor wireless networks. International Journal of Distributed Sensor Networks, 2(2), 147–159. doi:10.1080/15501320500259159 Mauve, M., Widmer, J., & Hartenstein, H. (2001). A Survey on Position-Based Routing in Mobile Ad Hoc Networks. IEEE Network, 15(6), 30–39. doi:10.1109/65.967595 McQuillan, J. M., Richer, I., & Rosen, E. C. (1980). The new routing algorithm for ARPANET. IEEE Transactions on Communications, 28(5), 711–719. doi:10.1109/TCOM.1980.1094721 Nayak, A., & Stojmenovic, M. (2006). Localized routing with guaranteed delivery and a realistic physical layer in wireless sensor networks. Computer Communications (Elsevier), 29(13-14), 2550–2555. doi:10.1016/j.comcom.2006.02.013 Perkins, C., & Royer, E. (2002). Ad hoc on demand distance vector (AODV) routing, Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, pp. 90-100.
Royer, E. M., & Toh, C. K. (1999). A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks. IEEE Personal Communications, 6(2), 46–55. doi:10.1109/98.760423 Ruiz, P., & Stojmenovic, I. (2007). Cost-efficient multicast routing in ad hoc and sensor networks. In Handbook on Approximation Algorithms and Metaheuristics, Chapman & Hall/CRC (Teofilo Gonzalez, ed.), Vol. 30, No. 18, pp. 3746-3756. Stojmenovic, I. (2002). Location updates for efficient routing in wireless networks. In Handbook of Wireless Networks and Mobile Computing. New York: John Wiley & Sons. doi:10.1002/0471224561.ch21 Stojmenovic, I. (2004). Geocasting with guaranteed delivery in sensor networks. IEEE Wireless Communications, 11(6), 29–37. doi:10.1109/ MWC.2004.1368894 Stojmenovic, I. (2006). Localized network layer protocols in sensor networks based on optimizing cost over progress ratio and avoiding parameters. IEEE Network, 20(1), 21–27. doi:10.1109/ MNET.2006.1580915 Stojmenovic, I., & Lin, X. (2001). Power aware localized routing in ad hoc networks. IEEE Transactions on Parallel and Distributed Systems, 12(10), 1023–1032. doi:10.1109/71.963415 Stojmenovic, I., Nayak, A., & Kuruvila, J. (2005). Design guidelines for routing protocols in ad hoc and sensor networks with a realistic physical layer. [Ad Hoc and Sensor Networks Series]. IEEE Communications Magazine, 43(3), 101–106. doi:10.1109/MCOM.2005.1404603 Stojmenovic, M. (2005). Swarm intelligence for routing in ad hoc wireless networks, Security and Routing in Wireless Networks (Y. Xiao, J. Li, and Yi Pan Yi, eds), Nova Science Publishers, pp. 163-184.
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Takagi, H., & Kleinrock, L. (1984). Optimal transmission ranges for randomly distributed packet radio terminals. IEEE Transactions on Communications, 32(3), 246–257. doi:10.1109/ TCOM.1984.1096061 Tseng, Y. C. Liao, W.H., & Wu, S.L. (2002). Mobile ad hoc networks and routing protocols. Handbook of Wireless Networks and Mobile Computing. New York: John Wiley & Sons. Wu, J. (2002). Dominating set based routing in ad hoc wireless networks. Handbook of Wireless Networks and Mobile Computing (pp. 425–450). New York: John Wiley & Sons. Zorzi, M. (2004). A new contention-based MAC protocol for geographic forwarding in ad hoc and sensor networks. IEEE Int. Conf. on Communications (ICC), Paris, Vol. 6, pp. 3481–3485.
KEY TERMS AND DEFINITIONS Ad Hoc Network: is a self-configuring network of mobile devices connected by wireless links. Routing: Sending a packet from a source node to a destination node.
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Proactive Routing: In this framework, each node exchanges its routing table with all of its neighbors and updates its own routing table if better routes to some destinations are available based on the new data. The entries in the routing table for one node are the costs of sending messages from that node to all other nodes using the best know routes. Reactive Routing: This type of routing is analogous to tourists trying to find an obscure address in a new city: they get closer and closer to the destination by asking people along the way. Hybrid Routing: Proactive and reactive routing approaches can be combined into a single approach. Proactive routing is applied if the destination is nearby, while reactive routing is applied when it is far away. Topological Routing: Routing where nodes do not have positional information. Localized Routing: Routing where nodes have positional information about themselves, their neighbors, and the destination, and no information about the rest of the network. Backbone: Subset of nodes so that each node not in the subset, has a neighbor from the subset
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Chapter 3
Mobile Ad Hoc Networks:
Protocol Design and Implementation Crescenzio Gallo University of Foggia, Italy Michele Perilli University of Foggia, Italy Michelangelo De Bonis University of Foggia, Italy
ABSTRACT Mobile communication networks have become an integral part of our society, significantly enhancing communication capabilities. Mobile ad hoc networks (MANETs) extend this capability to any time/anywhere communication, providing connectivity without the need of an underlying infrastructure. The new coming realm of mobile ad hoc networks is first investigated, focusing on research problems related to the design and development of routing protocols, both from a formal and technical point of view. Then link stability in a high mobility environment is examined, and a route discovery mechanism is analyzed, together with a practical implementation of a routing protocol in ad hoc multi-rate environments which privileges link stability instead of traditional speed and minimum distance approaches.
INTRODUCTION Mobile ad hoc networks consist of interconnected mobile hosts with routing capabilities. Considerable work has been done in the development of routing protocols for ad hoc networks, starting from Internet protocols developed in the seventies. In recent years, the interest in ad hoc networks has grown due to the availability of wireless communication devices.
New research directions in theoretical computer science and in particular in protocol design make use of game-theory concepts and tools. From this “perspective”, protocols are viewed as games with players represented by network nodes which “play” (participate in) the game; each node (agent) has its own utility function, such as network flow (to be maximized) or energy consumption (to be minimized.) This approach thus is a natural pointof-view of a distributed computing architecture,
DOI: 10.4018/978-1-60960-042-6.ch003 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.
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the most interesting paradigm in actual computer science. This is especially true since the advent of wireless networks based on IEEE 802.11 Protocol (IEEE, 1999, 2003) (and in particular with the definition of the new draft “n”) where it is possible to deal with a variable-speed link going from 1 to about 300 Mbps (Fan, 2004). Besides, considering that mobile networks (see Mobile landscape, 2009) have the peculiarity of movement (which makes the link speed highly variable and therefore very unstable), stability of routes becomes a difficult undertaking. Furthermore, as for its intrinsic nature, the same protocol IEEE 802.11 introduces a considerable network overhead to control the transmission at the expense of throughput. So we think that choosing a stable routing – mainly considering stable links – is preferable to taking into account only the link speed and/or length.
BACKGROUND Distributed Computing Environments In a distributed computing environment, such as a network, different pieces of software interact by following one or more well-defined protocols. As an example, the request to access a Web page (which is routinely issued by a simple mouse click) is served by a number of such interactions that involve, besides the browser and the remote Web server hosting the page, also a number of intermediate “agents” (called routers) that make the request/response message delivery possible. There is a plethora of protocols, which are primarily classified according to the ISO/OSI layered model of networking (see Figure 1). At the one end of the stack we have the physical layer protocols, whose goal is to make possible the delivery of raw sequences of bits between directly connected computers. At the
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Figure 1. ISO/OSI networking layered model
other end there are the application protocols supporting well-known high-level services, such as the already mentioned Web service (through the http protocol.) The most fundamental protocols are probably those that fall under the general term of TCP/IP: these are the protocols upon which the Internet is based, since they implement the key functions of routing and congestion/flow control. One common assumption in the distributed computing and networking literature is that the agents participating in a protocol execution follow the guidelines specified by the protocol itself (say, a router that is expected to route a data packet closer to its destination point will always do so, unless it is temporarily out of service.) There are clearly a number of settings in which this assumption makes sense. An obvious case, for instance, is that of a private network owned by a single Corporation. In the field of mobile networks (the one which we are most interested in here) there are application settings in which the above assumption applies
Mobile Ad Hoc Networks
Figure 2. Mobile ad hoc networks
as well. Consider, for instance, the case of sensor networks deployed with the goal of monitoring a given region. Another case is that of military networks. However, the assumption does not seem reasonable when, as in case of the Internet, the network is operated and used by different economic subjects, with possibly conflicting interests. Stated in other words, the assumption is not reasonable when the agents participating in the protocol may act selfishly with the aim at improving some personal utility. The obvious example here is a set of routers in a given domain that decide not to forward Internet traffic headed to domains belonging to competing organizations, or a military scenario where moving devices are not interested in routing enemy’s traffic. In the presence of selfish agents, the design of network protocols becomes a much harder task. Actually, this is not the whole story, as the influence of socio-economic factors calls for a completely new approach to the understanding and the design of network protocols. Quoting an influential author in the theoretical computer science community “the mathematical tools and insights most appropriate for understanding the Internet” and hence (mobile) networks “may come from a fusion of algorithmic ideas with concept and techniques
from Mathematical Economics and Game Theory.” (Papadimitriou, 2001) This new approach can be briefly synthesized as follows. First of all, the protocol and all the agents that possibly participate in the protocol define a game; this implies that each agent (player) has its own utility function. According to this scenario, a first goal is the understanding of the social cost of selfishness. In other words, given a measure of the overall performance of the protocol (this may be some global function, such as the average end-toend delay incurred by any message traveling the network), you may want to understand how bad, with respect to the ideal optimum performance, the network behaves due to the selfishness of some participants (as in Roughgarden & Tardos, 2000). A complementary goal is the design of protocols that aim at achieving some social objectives through the properties of rationality and truthfulness (Nisan & Ronen, 1999).
Mobile Ad Hoc Networks Mobile ad hoc networks are wireless networks characterized by the absence of any centralized coordination entity (see Figure 2). Each (mobile) device of the network, say a laptop or a PDA, can
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Mobile Ad Hoc Networks
Figure 3. (a)Transmission range (b) Communication graph
be only directly connected to the devices within its transmitting range, called neighbor devices; as a consequence, traffic destined to (or originated from) a non neighbor device has to be routed through one or more intermediate devices (multihop traffic.) This characteristic represents a major difference from other wireless networks (such as cellular phone networks or wireless LAN) and is the source of a number of challenging problems.
Topology Control Given a transmitting range for each device (see Figure 3a), an ad hoc network can be modeled as a (directed) graph whose nodes are the devices and there is an edge from node u to node v if and only if v is within u’s transmitting range. Such graph is often termed as the communication graph (see Figure 3b). Topology control is the problem of establishing some desired connectivity property for the communication graph acting on the devices’ transmitting range. Depending on the application scenario and the traffic model, the required connectivity properties may vary; the most obvious is full-connectivity (i.e., the graph must be strongly connected), but in some cases you may require stronger properties, such as bi- or tri-connectivity. Also, for reasons that are related with the protocols at the other levels, it is often required that the graph
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be symmetric, i.e., there is an edge (u, v) if and only if there is the edge (v, u). Clearly, the goal of topology control is to achieve the desired connectivity properties using the minimum possible transmitting powers (hence ranges.) Because of the potential reduction in the nodes’ transmitting power, topology control may have positive effects on both network lifetime and channel capacity, since a reduced range implies less contention on the wireless medium. Unfortunately, determining the minimum energy consumption topology is a hard problem (Blough et al., 2002; Clementi et al., 1999). Practical (suboptimal) protocols for enforcing connectivity are presented in Blough et al. (2003), Liu & Li (2002), Ramanathan & Rosales-Hain (2000).
Routing Routing is the problem of deciding the path in the communication graph for traffic destined to non neighboring nodes. Logically, the routing level is above topology control, but is strictly related to that. Some authors do not consider a separate topology control level (in particular, no topology control is needed if all the nodes have the same, maximum, transmitting range) and the network topology is “determined” by the route discovery
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stage itself. In consideration of the power required to transmit a packet to distance d (which grows at least quadratically with d), different sourcedestination paths can be characterized by very different energy consumption, and an obvious goal of routing is to choose the most efficient among such paths.
Medium Access Control (MAC) The wireless channel is shared among network devices; clearly, while one such device u is transmitting, no other device within u’s transmitting range may initiate another transmission (this resembles a non cooperative game scenario). When different transmitting powers are used, e.g., as a consequence of decisions made at the topology control level, the request-to-send/clear-to-send (RTS/CTS) mechanism needs to be tuned in order to silence all the possibly conflicting nodes. For instance, suppose that u is not within v’s range while v is within u’s. Then a RTS control message sent by v cannot silence u, and the latter may erroneously assume that the channel is available for transmission (Jung & Vaidya, 2002). Note that the communication graph of the above example is non symmetric. One may erroneously think that an obvious solution to the problem is simply to drop the (u, v) arc when building the network topology. However, the example shows that logical connectivity is in general different from physical connectivity. Logical symmetry enforced at the topology control level can be useful in the routing discovery phase, but what counts at the MAC level is the physical connectivity. This is a point that has been often overlooked in the literature on topology control.
Energy Efficiency Energy efficiency is a concern at all levels of the protocol stack. In particular, topology control has the specific goal of determining a low consumption communication graph. As for routing, it is
generally acknowledged that energy efficiency considerations must complement more traditional analysis based on packet loss rate, routing message overhead, etc. (Johansson et al., 1999) The ultimate goal is to increase the lifetime of individual devices and that of the network as a whole. Several definitions of network lifetime have been proposed: according to the simplest definition a network is not more alive when the first node dies; another definition considers the size of the largest connected component, which must contain at least 90% of the nodes. Even other definitions are possible. As a result of the above mentioned problems, the ad hoc network technology is still in its infancy, and no large-scale implementation of ad hoc networks has been reported yet. However, in spite of the above mentioned difficulties, there is an already large body of works that deal with ad hoc networks. This is due to the fact that ad hoc networks represent the most promising paradigm for the foreseen ubiquitous computing. As an example scenario of ubiquitous computing, consider a (wired) Internet access service to mobile users that many providers have already installed in a number of “public” sites (for instance, several airports and shopping centers are already offering this service for free.) The possibility, offered by ad hoc technology, of multi-hop access, where a mobile device communicates with the base station(s) via other mobile devices, would have a positive impact on such aspects as increased coverage area of the service and, as a result of the adoption of shorter transmitting ranges, increased network capacity and lifetime.
Security Another important issue concerning networks is security. Wireless networks use radio waves (i.e. electromagnetic signals) leading to an irradiation phenomenon in the interested area: signals permitting network connections exceed
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Mobile Ad Hoc Networks
Figure 4. Trusted relationships
needed area limits, reaching surrounding places in spite of a loss proportional to distance. This involuntary “broadcasting” makes it possible to gain access to network not only to authorized personnel, but also to everyone in the neighbors (as done in “warchalking” or Node Runner by hackers searching for accessible wireless network nodes, marking unprotected zones with conventional chalk signals.) Yet, same security problems are encountered in wireless ad hoc (multi–hop) networks: in fact, how sure can be a node about its outgoing traffic not being tampered with? From a pure cryptographic point of view, ad hoc network services do not imply “new” problems: authentication, confidentiality and integrity are issues already found in many other public communication networks. But in an ad hoc wireless network, trust becomes a key problem (Frodigh et al., 2000). Because the communication (radio) medium cannot be trusted (being intrinsically unprotected), cryptography is a mandatory choice, as well as relying on the cryptographic keys used. So, the basic idea is that of creating trusted key relationships without an external issuing Certification Authority (CA). In fact, a wireless ad hoc network
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comes out from spontaneously connecting and mobile nodes, and there is no warranty for a node to get trusted public keys from other nodes, nor they can exhibit third–party certificates. Nonetheless, if inter–node trust delegation is permitted, then nodes having already established trusted relationships may extend this privilege to other group members: let us see in detail how it works. The method is based upon a PKI (public key infrastructure) system. Suppose all nodes have connectivity with each other (e.g. through a reactive routing protocol), as shown in Figure 4. Initially, node N1 takes the role of server node in trust delegation procedure, and initiates the trusting process broadcasting a start message to the network. Every node receiving such a message forwards another one containing the trusted public keys set. N1 may so establish a trusted relationships map and identify them. In Figure 4 groups A, B and C participate to the trust chain. All nodes in B indirectly take part to the trust relationship with N1 (through node N3). Node N1 may so collect the signed keys received by group B through N3. Nodes in group C, instead, have not trusted relationships with node N1. However, a trusted relationship between nodes N7 (belonging
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Figure 5. Key exchange
to group C) and N1 can be “manually” created by means of trusted keys exchange. Node N1 can now collect the signed keys received from group C through node N7 (see Figure 5). Now, node N1 is ready to forward a message to the network containing all the collected signed keys. This procedure creates trusted relationships between nodes in groups A, B and C, and forms a new trusted group.
Protocol Design Issues As already pointed out, there is a growing interest in the computer science community to formulate new protocols (or, at the very least, to understand the behavior of currently used protocols) under the hypothesis of strategic behavior of the network nodes. In case of ad hoc networks, however, very few results are known, which almost always apply to routing. As an example of strategic behavior, a node may decide not to forward other nodes’ traffic, since during a message transmission a node consumes relatively more energy than during idle times. Of
course, if the majority of the nodes acts this way, no multi-hop traffic is possible. However, without cooperation, the ubiquitous computing scenario depicted in Figure 5 cannot occur since it is not economically feasible (Mas-Colell et al., 1995). The attention of a growing number of researchers is thus focusing on the design of protocols for ad hoc networks using the tools of game theory and mechanism design. Two properties are especially sought: rationality and truthfulness. According to the first, an agent is always motivated to participate in the game (i.e., the protocol), since its utility cannot decrease as a result of the participation. Truthfulness means that the best strategy (i.e., the one that maximizes its utility) for an agent is to behave according to the protocol. To this end, some forms of payment can be provided to motivate the players to act truthfully. Obviously, if the agents are rational and truthful, the protocol will achieve some target social goal (such as setting up power efficient end-to-end routes for all possible pairs of nodes.) Later on some practical ideas for the development of a routing protocol are discussed, upon which future research directions are based to make it rational and truthful.
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Mobile Ad Hoc Networks
As already mentioned, there are very few results dealing with the problem of strategic behavior in wireless ad hoc networks. At the routing level, protocols have been proposed for the establishment of routes among pairs of nodes using incentive payments to motivate intermediate nodes to act loyally (Buchegger & Le Boudec, 2002, 2002a, 2002b; Buttyan & Hubaux, 2000, 2001, 2003; Zhong et al., 2003). Anderegg & Eidenbenz (2003) introduced the first truthful routing protocol: it has however a number of shortcomings, being characterized by a high communication overhead and, more importantly, not enjoying the rationality property.
MANET ROUTING PROTOCOLS Introduction In wireline networks the task to establish the path that data packets must follow is carried out only by a limited group of devices called routers. In wireless ad hoc networks, instead, every host acts both as a router and a packet sender, so the classical routing protocols used by wireline networks are not applicable at all to MANETs. Existing routing protocols may be classified following three criteria: Based on the logical organization through which the protocol “describes” the network: from this point of view they may be divided in “Uniform” and “Non Uniform” routing protocols. In the first case, every node generates path control messages while answering (incoming) path control requests: all nodes have the same function. In the latter, instead, the way in which nodes generates and/or answers path control messages may be different for different group of nodes. Non Uniform protocols may be in turn logically subdivided into Neighbor Selection and Hierarchical: in the first case every node selects a neighbor node subset to calculate the path data packets must follow;
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in the second case, instead, nodes auto-organize in groups called clusters. For every cluster there exists a “controller” (master or cluster head) node, which has the task of coordinating the traffic inside it. It is obvious that Non Uniform protocols considerably reduce the signaling traffic vs. Uniform ones, thanks to the less number of nodes assigned to path calculations; but they pay an higher overhead due to the maintenance of complex high level structures. Based on the way routing information is obtained: from this point of view, protocols may be divided in Proactive (or Table-Driven), Reactive (or On-Demand) and Hybrid. The first continuously keep routing information updated through packet exchange at fixed time intervals: this allows immediate availability of routing at every request. The disadvantage is that Proactive algorithms produce signaling traffic also when no data packet is being transmitted; this may cause problems of excessive traffic load in the network, especially when nodes are rapidly moving, because the time interval between routing information transmissions has to be inversely proportional to the velocity with which nodes are moving, so as to get a correct routing. Examples of Proactive protocols are DSDV (DestinationSequenced Distance-Vector) and WRP (Wireless Routing Protocol.) In Reactive protocols a procedure is needed to establish the correct routing path only when packets are to be transmitted; in such a way signaling traffic is reduced, but with increasing delivery times (Johansson et al., 1999). Examples of Reactive protocols are AODV (Ad hoc On-Demand Distance Vector), DSR (Dynamic Source Routing), and TORA (Temporally Ordered Routing Algorithm.) finally, Hybrid protocols try to reach both previous protocols’ advantages, restricting Proactive algorithms application only to the nodes near the one doing data packet transmission. An example of Hybrid protocol is ZRP (Zone Routing Protocol.)
Mobile Ad Hoc Networks
Based on how the routing path is created: from this point of view, protocols may split in Source Routing and Non Source Routing. In the first ones the sending node determines the complete path to the destination, registering it directly into the packet; so, intermediate nodes only retransmit packets to those addressed by the previously established path. In the latter, instead, the only routing information contained in data packets is that represented by the best neighbor node to which communication has to be forwarded; consequently, every node must be able to optimize routing decisions.
Traditional Reactive Routing: Route Request Process Wireless ad hoc networks are generally made of nodes such as notebooks, PDAs, mobile phones. The characteristic of ad hoc networks is to have frequent changes in topology. In addition, to keep track of topology, there is a significant commitment of resources and a considerable overhead. Protocols of reactive type were designed for these environments. The aim is not to keep track of network topology: let us see the process (Paoliello-Guimaraes & Cerda-Alabern, 2007). If a node needs to reach a destination, it starts a discovery process to find the path. This process begins through the transmission – by the source node – of broadcast messages of Route Request (RREQ) type, with TTL set to 1 (Zou, 2005; Paoliello-Guimaraes & Cerda-Alabern, 2007). This RREQ message will only pass through a single node because of its TTL set to 1. Each message has a sequence number, so that only the first message is considered, while its subsequent copies are discarded. When a node receives the first copy of a RREQ from a source node, it stores the address, thereby establishing a return path (reverse route.) When the first RREQ reaches the destination, a reply message of type Route Reply (RREP) is sent to the source through the return path. This type
of protocol is generally efficient for a single rate network; in a multi-rate network, however, what counts is not to minimize the number of jumps to reach a destination, but the total throughput on a given routing. An existing technique taking into account, instead of the number of hops, the throughput is the MTM (Medium Time Metric) (Awerbuch et al., 2007; Paoliello-Guimaraes & Cerda-Alabern, 2007). In this technique a cost inversely proportional to the speed of the link is established; hence, the minimum cost link is chosen. This chapter fits in this area. In fact, in choosing the path, it is not enough to consider only the cost of the link: its stability should also (and perhaps especially) be considered (Dube et al., 1997).
Protocol Issues The Problem of Routing Instability in High Mobility Networks Although existing routing techniques are of indisputable validity, as a result of lengthy trials conducted in wired networks, a problem which causes the performance loss in wireless ad hoc networks impacting on the route discovery processes is the same routing instability, given that we are dealing with high mobility networks. What is “routing instability”? Let us consider a node represented by a mobile phone transmitting while in movement and think how variable is the signal received from a surrounding node as the issuer node moves in a closed or open environment. The level of the received signal, changing constantly, causes a continuously variable ratio of Signal-to-Noise (S/N), altering the bit-rate and consequently the “cost” of the link. This variability would lead to a continuous instability of routing, causing a continuous search of the “best path”. This implies an overhead’s increase impacting greatly on the performance and throughput of the entire network.
39
Mobile Ad Hoc Networks
A technique that keeps track of link stability is now presented, so as to avoid too unstable links in the route discovery process.
Table 1. Node link transitions
Keeping Track of Routing (In)Stability Keeping memory of stability means understanding how stable are connections between nodes; the idea is to have a table maintaining information associated with each link on its state transitions. With the word “transition” you can consider the link’s moving from one transmission intensity (measured in dBm and equal to the signal/noise ratio) to another: Table 1 illustrates each node’s link associated with its number of transitions.
Stability Index and Threshold Let us now define what causes the increase in the number of transitions associated with the link. In order to record the link’s stability, omit all transitions lying within a defined tolerance, i.e. those which do not make a significant loss in link’s performance. The key idea is to record a transition whenever the link gets a difference between the new Ii and the previous Ii-1 sampled transmission intensity outside a predefined absolute percentage δI. So you keep track of a transition when: Ii − Ii − 1 > δI Ii − 1 In order to correctly keep track of transition frequency, it is advisable to sum the number of transitions of a link compared to a period of observation. For example, if N is the number of transitions in the time interval ∆T, the frequency F will be: F=
40
N ∆T
Node link
No. of transitions
L1
N1
L2
N2
L3
N3
...
...
Observation’s Time Interval To establish a statistical time interval ∆T is not simple. You can guess it to be inversely proportional to the average transmission intensity of the links and directly proportional to the number of nodes. Thus, given a network of N nodes, with links’ average intensity μI, you can say that: ∆T α
N µI
After this interval the various counters (column “Number of transitions” in Table 1) are zeroed. At the end, a maximum threshold α for the number of transitions in the time interval remains to be defined. Consider, for example, a time interval ∆T = 300 msec. and a possible maximum value Fmax for the transition frequency F of one transition every 15 msec. From that, you have α = ∆T · Fmax = 20. In a nutshell, if there are more than 20 transitions within an observation period of 300 msec. (i.e. F > Fmax) you will say that the network link is unstable. In order to practice an effective implementation of the mechanisms given above, one can follow two approaches. The first is to monitor the stability of the link, the second provides for the updating of the link stability table only after a route discovery request. Given the high overhead required by the first approach, it seems preferable to implement the second as better detailed later.
Mobile Ad Hoc Networks
Influence of Best Path Choice in Route Discovery When deciding on the best path two alternative approaches called “Link Stability” and “Link Rate” are considered and described below in detail.
Coming back to the above sketched technique, the algorithm − among two links of equal speed − will choose (only under such conditions) the stablest. To define this stability the same considerations outlined in the previous technique can be done.
Link Stability
Protocol Design and Implementation
This technique, as the term shows, prefers link stability and, then, in the route choice to build the path it excludes a priori all links having a transition frequency F above a certain threshold. Returning to our example, if Fmax = 1/15 is the threshold corresponding to a transition every 15 milliseconds, all links having F > 1/15 will be excluded from the choice. Note that, albeit being true that the stablest link has to be chosen, a stable link could also be one with a zero (i.e. not working) signal intensity. Therefore a minimum threshold Imin should be set for the link intensity, below which the choice cannot be done even if the link is very stable. So, considering threshold values Fmax and Imin a network link is stable when I ≥ Imin and F ≤ Fmax.
From what said, the focus is here on the approach called “Link Stability”, in which the characteristic parameters for network monitoring are highlighted, i.e. the transition frequency of the received signal intensity (dBm) and the signal intensity itself. In the protocol design and implementation a crucial role is played by the link stability table. To optimize efficiency, the table will be updated at the beginning of every route discovery process and used in the same process to identify the route.
Link Rate In this technique stability becomes of secondary importance: the speed of the link is in any case to be preferred. So, when choosing routes for the construction of the best path, the stablest link will be chosen only within equal links’ cost (at an equal speed.) But what does equal speed mean? first, it should be noted that from a practical point of view having two links of the same speed may not correspond to reality, if not for a purely random case. Therefore two links are of “equal speed” if the difference in speed between them is no more than 20%. E.g., if the link L1 has a bit rate V1 = 100 Mbps you can say that a second link L2 has the same speed V2 if 80 Mbps ≤ V2 ≤ 120 Mbps.
The Routing Process Each node manages a routing-path table keeping track of all incoming and outgoing connections. The table contains, with respect to a classic routing table, not the mere next hop off an interface but the entire route (that is, all node addresses belonging to the route to destination) and a time-stamp field used to delete the obsolete routes not used for more than a threshold time limit, as shown below. Observing Figure 6, the upper layer (Application Layer) sends a route request to the network layer. The routing protocol (interior protocol) verifies if the destination address already exists in the device routing-path table. If the destination address doesn’t exist, the route discovery process is activated in order to enter the destination node address and its path in the routing-path table. If the destination address exists in the device routing-path table, the relative path (included in the routing-path table) will be used and updated by the real time-stamp value of the sender. In MANETs, the paths included in the routing-path table cannot be static since the network topology
41
Mobile Ad Hoc Networks
Figure 6. WLAN communication of two nodes (source CNET)
changes very frequently; the responsibility of route availability is demanded to the upper layer (because there may be an expired timeout waiting for an acknowledgment.) It’s still the upper layer to decide whether to delete a route from the table, even if its time limit has not expired: this means that the upper layer will order a route discovery every time a packet nondelivery happens.
The Stable/Unstable Link Definition To define the (un)stable link during the operation of route discovery process, the node must collect n transmission intensity values Ii, i = 1..n (expressed in dBm) during a statistical time interval ∆T, updating the minimum value Is = mini {Ii} of the sampled data and a transition counter C every time the absolute relative difference between the two last observed values is outside the predefined percentage threshold δI. These values, at the end of ∆T, will be used to check that the received signal intensities Ii are higher than or equal to a minimum acceptable threshold Imin and if they overcome the percentage threshold δI not too often.
42
In the example of Table 2, five intensity signal measurements in dBm are sampled over an observation period ∆T = 300 msec and checked against a minimum intensity threshold Imin = −85 dBm and a percentage threshold δI = 20%; a maximum transition frequency Fmax = 1/15 is also assumed, from which a maximum acceptable transition counter α = ∆T · Fmax = 300 · 1/15 = 20. The transition counter C is increased every time the percentage ratio of the last two sampled dBm values overcomes the threshold. Note that the minimum intensity threshold is never violated (i.e. IS = −80 > Imin = −85). So, the link is stable because also the transition counter C = 3 does not overcome the maximum α = 20.
Route Discovery Packet Fields The route discovery packet contains the following fields: destination node address; sender node address; sender node time-stamp; hop-count (number of links, or nodes, passed through); number of stable links;
Mobile Ad Hoc Networks
Table 2. Link stability table I i − I i −1 I i −1
Sample #
Intensity Ii (dBm)
Minimum value IS (dBm)
1
-50
-50
0%
0
2
-70
-70
40%
1
3
-80
-80
14%
1
4
-40
-80
50%
2
5
-70
-80
75%
3
pointer to a stack containing addresses of nodes traversed from the sender (bottom) to the recipient (top.)
Route Discovery Algorithm The route discovery process can be summarized as follows. Every node initiating a transmission activates a route discovery process. The transmitter node sends a packet including the destination address and the above mentioned fields. Every node receiving the packet checks if the destination address matches itself.
Matching The receiving node stores the return path, and the percentage of stable links over all links traversed. Later, after receiving the first packet, it waits for any other route discovery packet related to the pair sender-timestamp for a specified time ∆TB. If in this time another route discovery packet arrives, the node compares the percentage of stable links over all links passed through with the previous stored percentage. If it is higher, the new relative path and new percentage will be stored, otherwise the packet will be ignored. All other arriving route discovery packets will be treated the same manner until ∆TB expires. The recipient, once elected
% of oscillation =
Transition counter C
the best route among all considered in the above said interval: sends an ACK using the final reverse route. This acknowledgement will be uniquely associated with the route discovery packet transmitted by sender with its time-stamp included; inserts the reverse route (the winning route) in its routing-path table, binding it to a local time-stamp. Reverse-route will be used as long as the routing is valid, i.e. while the recipient is reachable.
No Matching The receiving node checks whether its address is in the stack of node addresses traversed: if yes, it drops the packet, since it is a broadcast route discovery packet previously handled by itself, so the broadcast storm effect will be excluded; if not, it sends a broadcast route discovery packet to the same destination address adding the node address from which the packet is coming from, plus a stable link counter increased by 1 (in case the receiving node has detected a stable link) and a counter storing all links traversed. Return to Step 3. It would be useful to conduct proper simulations to test the described algorithm and obtain significant values for the following parameters: statistical time interval ∆T;
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Mobile Ad Hoc Networks
number n of samples considered in the time interval; minimum threshold signal intensity Imin in dBm; percentage threshold of transmission swings δI ; allowed frequency swings limit Fmax to define a stable link; % of stable links over total traversed links for routing-path table; sender node (waiting for acknowledgement) time-out to initiate a new route discovery; time-out to declare an “old” route in the routing-path table; recipient node wait-time ∆TB to receive the route discovery.
CONCLUSION AND FUTURE RESEARCH DIRECTIONS Future research trends reflect the general goals introduced at the end of paragraph Distributed computing, which characterize the new scenario for the understanding and the design of open networks. First of all, it is useful to understand − with respect to some potential application scenarios for ad hoc networks − under which conditions the known “classical” protocols guarantee the achievement of the requested social goals. This kind of analysis has been done with respect to some Internet protocols, such as BGP routing (Markakis & Saberi, 2003.) Future work must possibly answer the following questions, among others. Under which scenario (i.e., traffic model, node payoff, etc.) can we avoid the formation of coalitions, that is, the formation of subsets of nodes that can increase their payoff by seceding from the rest of the network? In the negative case, can some relatively simple payment mechanisms help driving the network activity towards socially better outcomes? It is likely that, under many potential scenarios, the known protocols for ad hoc networks are not strategy proof (i.e., the rationality and truthfulness properties are not both satisfied.) Hence, the more
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ambitious research directed towards the design of new protocols resilient to strategic manipulations. As pointed out in paragraph Protocol design issues, there are already some proposals for the routing level, although no strategy proof protocol is known to date. However, it would be interesting to investigate strategic issues also at the topology control level as well as at the application level. The simple techniques exposed are suited to any type of mobile ad hoc network and any kind of speed, by the definition of the indicated parameters. Therefore, this methodology can probably be implemented in any type of network environment, even in networks with very high density of nodes, as wireless networks in delimited environments such as university campus, airports, shopping malls, etc. It would be useful to study how these techniques, when implemented, impact on the energy consumption of nodes. This study would not aim at finding an absolute value of absorbed energy, rather a percentage value relative to the generated network overhead.
REFERENCES Anderegg, L., & Eidenbenz, S. (2003). Ad hocVCG: a truthful and cost-efficient routing protocol for mobile ad hoc networks with selfish agents. In Proceedings ACM Mobicom (pp. 245–259). Awerbuch, B., Holmer, D., & Rubens, H. (2007). The medium time metric: High throughput route selection in multirate ad hoc wireless networks. Mobile Networks and Applications, 253–266. Blough, D. M., Leoncini, M., Resta, G., & Santi, P. (2002). On the symmetric range assignment problem in wireless ad hoc networks. Proceedings IfiP Conference on Theoretical Computer Science (pp. 71–82).
Mobile Ad Hoc Networks
Blough, D. M., Leoncini, M., Resta, G., & Santi, P. (2003). The k-neigh protocol for symmetric topology control in ad hoc networks. Proceedings ACM MobiHoc, 03, 141–152.
Dube, R., Rais, C., Wang, K., & Tripathi, S. (1997). Signal Stability-Based Adaptive Routing (SSA) for Ad Hoc Mobile Networks. IEEE Personal Communications, February (pp. 36–45).
Buchegger, S., & Le Boudec, J. (2002). Cooperative routing in mobile ad hoc networks: current efforts against malice and selfishness. Lecture Notes on Informatics, Mobile Internet Workshop, Informatik 2002, Dortmund, Germany.
Fan, Z. (2004). High throughput reactive routing in multi-rate ad hoc networks. Electronics Letters, 40(25), 1591–1592. doi:10.1049/el:20046622
Buchegger, S., & Le Boudec, J. (2002a). Nodes bearing grudges: towards routing security, fairness, and robustness in mobile ad hoc networks. Proceedings of the Tenth Euromicro Workshop on Parallel, Distributed and Network-based Processing (pp. 403–410). Buchegger, S., & Le Boudec, J. (2002b). Performance analysis of the CONfiDANT protocol: cooperation of nodes – fairness in dynamic ad hoc networks. Proceedings of ACM Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc). Buttyan, L., & Hubaux, J. (2000). Enforcing service availability in mobile ad hoc WANs. Proceedings of IEEE/ACM Workshop on Mobile Ad Hoc Networking and Computing (MobiHoc). Buttyan, L., & Hubaux, J. (2001). Nuglets: a virtual currency to stimulate cooperation in selforganized ad hoc networks. Technical Report EPFL. DSC. Buttyan, L., & Hubaux, J. (2003). Stimulating cooperation in self-organizing mobile ad hoc networks. ACM/Kluwer. Mobile Networks and Applications, 8(5), doi:10.1023/A:1025146013151 Clementi, A. E. F., Penna, P., & Silvestri, R. (1999). Hardness results for the power range assignment problem in packet radio networks. Proceedings 2nd International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (RANDOM/APPROX ’99). LNCS (1671) (pp. 197–208).
Frodigh, M., Johansson, P., & Larsson, P. (2000). Wireless ad hoc networking: the art of networking without a network. Ericsson Review, No. 4 (pp. 248–263). IEEE (1999). Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher speed Physical Layer Extension in the 2.4 GHz Band. IEEE Supplement to Part 11, Rev. IEEE STD 802.11b. IEEE (2003). Wireless LAN Medium Access Control (MAC) and Physical Layer specifications: Further Higher-Speed Physical Layer Extension into the 2.4 GHz Band. IEEE Draft Supplement to Part 11, Rev. IEEE STD 802.11g/D8.2. Johansson, P., Larsson, T., Hedman, N., Mielczarek, B., & Degermark, M. (1999). Scenariobased performance analysis of routing protocols for mobile ad hoc networks. Proceedings of the ACM/IEEE International Conference on Mobile Computing and Networking (pp. 195–206). Jung, E. S., & Vaidya, N. H. (2002). A power control MAC protocol for ad hoc networks- Proceedings ACM MobiCom 02 (pp. 36–47). Liu, L., & Li, B. (2002). Capacity-aware topology control in mobile ad hoc networks. Proceedings IEEE International Conference on Computer Communications and Networks (pp. 570–574). Markakis, E., & Saberi, A. (2003). On the core of the multicommodity flow game. Proceedings ACM Electronic Commerce conference.
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Mas-Colell, A., Whinston, M., & Green, J. (1995). Microeconomic theory. New York: Oxford University Press. Mobile landscape - Graz in real time. Retrieved July 16, 2009, from http://senseable.mit.edu/graz/ Nisan, N., & Ronen, A. (1999). Algorithmic mechanism design. Proceedings of the 31st Annual ACM Symposium on the Theory of Computing (pp. 129–141). Paoliello-Guimaraes, R., & Cerda-Alabern, L. (2007). Adaptive QoS reservation scheme for ad hoc networks. Lecture Notes in Computer Science, 102–112. doi:10.1007/978-3-540-70969-5_8 Papadimitriou, C. H. (2001). Algorithms, games, and the Internet. Proceedings of the 33rd Annual ACM Symposium on the Theory of Computing (pp. 749–753). Ramanathan, R., & Rosales-Hain, R. (2000). Topology control of multihop wireless networks using transmit power adjustment. Proceedings - IEEE INFOCOM, 404–413. Roughgarden, T., & Tardos, E. (2000). How bad is selfish routing? Proceedings of the 41st Annual Symposium on the Foundations of Computer Science (pp. 93–102). Zhong, S., Yang, R., & Chen, J. (2003). Sprite. A simple, cheat-proof, credit-based system for mobile ad hoc networks. Proceedings of INFOCOM (pp. 1987–1997). Zou, S., Cheng, S., & Lin, Y. (2005). Multi-rate aware topology control in multi-hop ad hoc networks. Proceedings IEEE Wireless Communications and Networking Conference (WCNC’05) (pp. 2207–2212).
KEY TERMS AND DEFINITIONS Link: a hardware connection linking two or more electronic devices, normally using different
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types of cables each designed for a certain standard of data transmission. In addition to the electric cable is also possible to make a connection through fiber optics, radio waves and infrared (IrDA). Link Stability: transmission error rates (due to signal weakness or external environment factors such as white noise and wireless interference) can result in an unstable link. A link is stable if it has a low signal variation frequency with a minimum acceptable signal intensity. MANET: (Mobile Ad hoc NETwork): an independent system of mobile devices connected by ad hoc wireless links. All nodes in the system cooperate in order to correctly route packets in multihop forwarding mode. Due to the unpredictable mobility of nodes, the network topology may change constantly. Ad hoc networks are built and used as appropriate in extremely dynamic environments, not necessarily with the help of an already existing infrastructure, such as after natural disasters, military conflicts or during emergencies. Multi-Rate: a transmission system in which speed (rate) can vary from point to point. The use of different sampling rates within the same system offers several advantages such as lower computational complexity, adequate transmission rate and less memory capacity requirements. Network: a system that allows the sharing of information and resources (both hardware and software) among several devices (hosts), providing an information transport service to a user population distributed over a more or less extensive area. Computer networks generate potentially high volume traffic, unlike the telephone, efficiently managed through the technology of packet switching. Protocol: a set of rules formally described, defined in order to facilitate communication between one or more entities (network protocol, in case of remotely connected entities). All these rules are defined by specific standards (see ISO/ OSI), of many different types, depending on the entities and communication means involved.
Mobile Ad Hoc Networks
Route Discovery: a request to find the best available route to the destination, when sending a message. Routing: in packet-switching networks, routing is the function of a device (router) that decides the best path along which to send a received packet. Each packet is forwarded from the source to a router, and from this to the next, until reaching the desired destination. The router often uses a table with destination network addresses to decide where to send each packet. The format
of this table and the way it is populated and possibly updated are specific to the different routing protocols adopted. Wireless: the term covers communication systems between electronic devices, which do not use cables (traditional cabled systems are called wired). Generally, the wireless uses radio waves at typically low power, but also infrared radiation or laser.
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Chapter 4
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa Bwalya Kelvin Joseph University of Johannesburg, South Africa Chris Rensleigh University of Johannesburg, South Africa Mandla Ndlovu Botswana Accountancy College, Botswana
ABSTRACT The convergence of wireless applications presents a greater hope for consolidating e-Government (ICTenabled or online government) applications even in resource-constrained countries such as those in Africa. This chapter presents an exploratory study that aims at discussing the extent as to how convergence of wireless technologies from different vendors promises to contribute to the consolidation of e-Government applications in Sub-Saharan-Africa (SSA). This is done by reviewing the different adoption stages of ICT and e-Government in SSA. It looks at challenges facing adoption of wireless technologies (GSMs, Wireless Internet Access, satellite transmission, etc.) across all the socio-economic value chains in SSA. The chapter looks at Botswana and South Africa as case studies by bringing out the different interventions that have been done in the realm of facilitating a conducive environment for the convergence of different wireless technologies. Out of the analysis of legal, regulatory, market and spectrum policies affecting the adoption of wireless communications in SSAs, the chapter draws out recommendations on how to consolidate wireless communications to be adopted in different socio-economic setups (e.g. e-government, e-Health, e-Banking, etc.). DOI: 10.4018/978-1-60960-042-6.ch004 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
INTRODUCTION Wireless technologies (especially Internet-ready mobile phone technology) have seen higher adoption rates in the SSA region partly due to an escalation in the existence of Wireless Application Service Providers (WASPs) in SSA. This penetration has encouraged computing mobility which has encouraged spill-over applications to almost all the major sectors of the socio-economic hierarchy. One such e-application with great potential is the application of wireless technologies in the e-Government domain. Appropriate convergence of the different wireless technologies will enable increase access to information and public services in the framework of e-Government. As Africa’s technological landscape has kept growing exponentially, it is important to take advantage of this growth and promote e-Government which will hopefully bring about responsive, transparent and accountable management of national resources. Many literature sources that point to the fact that mobile technologies are growing at an alarming rate in Sub-Saharan Africa (SSA) (TRASA report, 2009; Bwalya, 2009; Touré, 2006; Graham et al., 2006; ITU Report, 2008). Telecommunication service providers in the SSA region have made Internet access possible through a multitude of Information and Communication Technology (ICT) devices such as personal digital assistants (PDAs), mobile phones etc. This means there is an increase in the number of people accessing the Internet making it possible for governments in SSA to consider implementing the e-Government governing model. In addition, e-Government can be a prerequisite to strategic initiatives avoiding rampant corruption and red-tape that characterizes most Africa’s government organs and thwarts effectiveness of public service delivery systems (Bwalya, 2009). This chapter defines E-Government as the use of ICTs to provide interactive public services linking then government, citizens and businesses. E-Government enables transparent government processes ushering in improved
service delivery/transactions which encourage participatory governance where citizens and businesses are accorded the chance to interact effectively with government departments, organs and line ministries. However, setting up a full-fledged e-Government interactive environment for SSA countries has been a huge challenge because of the different costs that come with its implementation. Before we look at the different challenges of e-Government implementation, let’s briefly look at the different benefits of using e-Government. The convergence of wireless technologies entails that different wireless ICT platforms cannot decode certain signals from a named source because of differences in IEEE standards. An example of this is that you can have a situation where WiFi (IEEE 802.11) can decode some signals from a source and WIMAX (IEEE 802.16) cannot decode the same signals that WiFi can. This may be because of protocol mismatch, different in synchronization and frequency bands. The figure below presents one context of convergence of wireless technologies where a WiFi device tries to join a WiMAX network and it can’t decode the signals because the base station which encodes the said signal uses WiMAX-OFDM. This convergence of wireless technologies can happen amongst many technologies such as GSM, CDMA, TDMA and iDEN or 1G, 2G, 2.5G, 3G to 4G in cellular phones. This convergence may also entail ability of mobile agents/devices to decode encoded signals on networks such as wireless LAN, MAN, sensor networks, RFID, and so forth. Since, generally, even ordinary individuals now have access to Internet-enabled mobile phones; implementation of e-Government on mobile platforms has much promise for Africa. This is compounded in the understanding that the universality in the signal decoding capabilities of different mobile devices is key to global access of e-Government information and public services in ubiquitous environments. This form
49
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
Figure 1. Convergence of wireless technologies
of e-Government is called m-Government (discussed in the next section). In the SSA, a study by Maumbe and Owei (2006) investigated the adoption of m-Government in South Africa and outlined the different challenges that prevent the transition ofm e-Government to m-Government. Many authors (Bwalya, 2009; ) have outlined the different benefits (Mutula et al., 2010; Aladawi, Yousafzai, & Pallister, 2005; Warkentin, Gefen, Pavlou, & Rose, 2002) that come with the implementation of e-Government: a) the reduction in cost and the increase in the efficiency levels in public service delivery platforms brought about by appropriate coordination mechanisms amongst different government line ministries, organs and branches, b) growth in confidence levels in government processes as with the proper implementation of e-Government, there is resource accountability and responsiveness, c) reduction in corruption levels by public servants, d) facilitation of participatory democracy as citizens are involved in the different governance processes, e) ensures appropriate functioning for interaction mechanisms between the state, business and citizens, f) ensures openness and transparency of activities carried out by the public administration bodies for business and society, g) enables citizens to participate in the governance processes anywhere
50
and at anytime and h) encourages the interaction amongst different developmental partners (e.g. government, businesses and ordinary citizens) in exchanging governing ideas that could later transform the socio-economic status of a country. These different benefits are achieved after the major principles for e-Government applications have been appropriately applied. Reviewing the different countries that have successfully implemented e-Government reveals that the following principles should be employed for e-Government to succeed: a) platform for common national strategy formulation that would define goals, principles, objectives, indicators evaluating the process of e-Government implementation (implementation roadmap or e-Government strategy); b) synchronization of e-Government implementation process with administrative reforms and mainstreaming of e-Government systems at all levels of the government hierarchy e.g. at local government levels, c) creating tax and institutional mechanisms promoting demand for ICT and d) openness of e-Government introduction program development and accountability on its implementation. E-Government is looked at as a multi-dimensional entity which depends on availability of appropriate ICT infrastructure, convergence of
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
ICT technologies, ICT skills of people, acceptable usability levels of web portals, cost of Internet access, cost of ICT devices, ICT culture, and so forth. For e-Government to be intermittent challenges to e-Government adoption can be attributed, principally, to lack of proper ICT infrastructures e.g. lack of fibre optical networks for broadband Internet communications. Very limited fixed networks are available in most parts of Africa (Bwalya, 2009). This further justifies the need to encourage provision of e-Government services through mobile platforms (m-Government). On another hand, in some places, telecommunications operators and other added-value service providers face a lot of difficulties in competing with stateowned competitor companies who enjoy wide monopolies and are fond of practices that do not encourage fair competition. This means it becomes difficult to have a mature telecommunications environment further negatively impacting on eGovernment efforts. All this is compounded by lack of proper monitoring, legal, regulatory and institutional frameworks in place. Other challenges have been lack of reliable power supply in many zones (mainly rural zones) where people can not charge the mobile terminals, or connect a computer to access to Internet, lack of the technological culture to understand the possibilities that these technologies could offer, and the difficulties to sure the investment return due the economical situation of great part of population, and so on. Another issue that confronts massive adoption of wireless technologies is the security issue. Enforcing of security inn wireless environment is more challenging and expensive that may be in convertible wired networks. The aforementioned challenges clearly justify the need to seek understanding of the premise of convergence of wireless technologies and its impact on e-Government. This further brings us to investigate the adoption trends of m-Government in the SSA and to explore on what interventions have been put in place to encourage the proliferation of e-Government in SSA. This chapter does
just that. To do this, the chapter surveys how the convergence of different wireless technologies, and other interventions, have aided in promoting adoption of e-Government in South Africa and Botswana. The next section discusses the background and gives a succinct motivation of this survey in a view to unearth the potential for the convergence of wireless technologies in promoting e-Government. It also discusses the pursuit of wireless e-Government applications in the pursuit of promoting the mobile governance model (m-Government), which is an emerging form of e-Government. Thereafter, the chapter presents findings on the exploratory studies of different convergence aspects of e-Government models in South Africa and Botswana. The next section after this gives the solutions and recommendations for advancing convergence of wireless technologies in facilitating m-Government applications in SSA and immediately thereafter, the future research directions are given. The chapter ends with a conclusion that gives a recap of what has been discussed in this chapter. Background In this plethora of technologies, convergence of telecommunications and wireless communications brings together voice telephony and more affordable wireless (mobile) services into more efficient interactive platforms. Broadband, a key requirement for productive Internet access, is still unavailable and/or unaffordable in most of the developing world (Lanwin, 2002; Bwalya, 2009; Pheko, 2009; Odinma, Oborkhale, Kah, 2007). These different convergence platforms aim for appropriate information dissemination and exchange of ideas, pulling people of different backgrounds out of different situations such as poverty and ameliorating their socio-economic standing. Convergence of wireless technologies offers great hope as a platform for e-Government applications in SSA as Africa has the highest growth rate of mobile technology adoption worldwide (Lanwin, 2002; Bwalya, 2009; Du Preez, 2009). As aforementioned, convergence of wireless technologies has brought about a re-
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Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
ality of the proliferation of a converged form of e-Government where public services and sharing of information is done through mobile platforms (mobile government: m-Government). Before we proceed further, let’s have a look at definitions and implications of m-Government. The extension of e-Government services to m-Government coupled with massive growth in mobile and wireless technologies has been acknowledged by several authors (Amitava and Agnimitra, 2005; Amailef and Jie; Karantjias, Papastergiou and Polemi, 2007). In a nutshell, m-Government is looked at as the use of mobile and wireless communication technology in government for service and information delivery to citizens and organizations (Fasanghari and Shamimi, 2009). It is thus in order to refer to m-Government as a complex business strategy for the efficient utilization of all wireless devices providing for instant availability of services and information for better benefits to users Amitava and Agnimitra, 2005). The ultimate goal of m-Government is to push forward the e-Government agenda by utilizing mobile and ubiquitous platforms. Further, Fasanghari and Shamimi (2009) quoting from other sources, mention that m-Government further facilitates service presentation to the citizens with access to the information and services in any time and any place made possible possible through connected wireless tools to the Internet. The paper by Amitava and Agnimitra (2005) suggested that the network architecture that provides m-Government comprises a hierarchical one with various wireless/wired access layers. These layers include the following: the cellulular, short range and the personal network layer (for detailed descriptions of these layers please refer to Amitava and Agnimitra, 2005). Amailef and Jie (2008) has recognized the fact that within the context of e-Government, mGovernment offer more access to information and services for citizens, businesses, and non-profit organizations through wireless communication networks and mobile devices and platforms
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such as pagers, PDAs, cellular phones, and their supporting systems. This has all been facilitated with the advent advances in Internet and wireless technologies which have brought forth mobility in e-applications. With intermittent growth of mobile technologies in Africa, m-Government presents a new way for enhancing interaction amongst citizens, businesses and government through mobile platforms towards improved content access, transparency, participations, and so forth. At the center of m-Government are issues of interoperability as different sets of mobile devises are involved in mobile e-transactions. This is where convergence of different wireless gadgets in heterogeneous computing environments is sought. In fact, interoperability requires easily identifiable and publishable mobile services as well as clear electronic and mobile interfaces for the establishment of secure and reliable connection points (Karantjias, Papastergiou and Polemi, 2007). Friske (2003) stated that convergence can be perceived through its division into two components: the technical and functional. The technical element refers to the ability of any infrastructure to transport any type of data whereas the functional aspect characterizes the means by which users are able to integrate the functions of computers, television, media and voice into a single device. However, it is worth mentioning that having lots of mobile devices does not enable m-Government. The true measure of convergence in this context is checking which applications are available, and how understandable, accessible and useful they are to the common citizen through the use of different mobile platforms. Different devices within different spectra can now do the same functions and are highly interoperable. Apart from the obvious uses of e-Government (access to government information from portals, downloading of public service forms, and so forth), some of the practical uses of m-Government have been in emergency response systems (Amailef and Jie, 2008). This suffices to mention that mGovernment can be used in many e-applications
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
not limited to governance in the broader sense of the word. The convergence of different wireless ICT devices can encourage the growth of e-Government in the form of mobile government (m-Government). M-Government implementation involves the use of all wireless and mobile technology, services, applications and devices for improving benefits to the parties involved in e- Government including citizens, businesses and all government units (Kushchu, 2003). In most countries trying to implement e-Government, some of the early adopters of m-Government services include law enforcement, fire fighting, emergency medical services, education, health and transportation, immigration, border and coastal security and disaster response and management (Amine, 2005). M-Government implementations are emerging as one of the additional value-added features for the integrated and flexible data communication and exchange mechanism among government units, citizens and businesses. This can further be supported by the penetration of mobile technology and the relative low cost of entry into mobile connectivity, the convergence of wireless Internet and telecommunication networks, allowing information once only available on a computer to be received through mobile phones, and the shift towards higher data transfer rates and 3G services which promises to make more information available at faster speeds. M-Government offers a relatively lower cost of mobile phone technology versus Internet technology which has drastically lowered the entry barriers for ordinary individuals to participate in e-Government activities. This is because the use of WIMAX and WiFi technologies presents a real and low cost alternative to fixed networks to allow Internet access. This further presents an opportunity for WIMAX to combine with other current ICT infrastructures in these SSA countries where overreliance on high cost Internet connection through GSM/3G networks may not provide wide band for appropriate Internet connectivity.
Different wireless platforms have undergone transformations in order to be of much value to its customers and to be interoperable with other technologies, ICT devices and applications. Odinma et al. (2007) identifies broadband wireless networks as mainly comprising two types: fixed and mobile wireless. These can be Wireless Fidelity (Wi-Fi), which is an IEEE 802.11 standard and Worldwide Interoperability for Microwave Access (WiMax), which is an IEEE 802.16 standard. TRASA (2009) gives a historical overview of different transformations and convergence of different wireless technologies. The second generation (2G) wireless communication employed digital technologies such as the GSM, CDMAOne, iDEN, IS-136 and PDC. In between the 2G and Third Generation (3G) is the 2.5 Generation (2.5G) technologies, namely, GPRS which evolved from the GSM, EDGE which evolved from the GSM but it has higher speed than the GPRS and CDMA2000 1XRTT which evolved from CDMAOne. Al-Sherbaz (2008) acknowledges that WiFi, the widely deployed predecessor technology, is inexpensive and readily available with multiple vendors. But WiMAX offers better spectrum efficiency, data rate, and long-distance capability. Developing of the wireless environment can be facilitated by adopting the Fixed-Mobile Convergence (FMC) which is an analysis of the interworking between cellular networks and a variety of wireless technologies such as WLAN, WiMAX, RFID and UWB (Ghetie, 2008). Rossel (2006) states that the first understanding of mobile government is linked to the increase of space and time in accessing administration services to provide “mobile” with enhanced linkage and informational and transactional options or to develop new citizen opportunities linked with mobility issues and enhanced government services. This entails adapting government and administration services to be accessible in a ubiquitous manner, developing new options and services based on ubiquitous access and multi-channel possibilities, mobile services for mobile organizations, facilitat-
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Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
ing the mobile state, and mobile administration of administration agents or agencies. Even after having achieved full convergence of wireless technologies or having one of the fastest growth rates in mobile and wireless and convergence networks, there are still some challenges that need to be addressed to facilitate appropriate facilitation of e-Government systems. Lanwin (2002) identifies the different challenges that come with m-Government as a) Privacy and security, b) securing wireless e-mail, c) protection against loss of data, d) securing handheld access to the corporate network, e) deploy and manage security policies for many devices, f) accessibility, g) mobile authentications and h) mobile payments. Specifically, South Africa has faced a number of challenges in implementing m-Government as outlined by Maumbe and Owei (2006). Some of the challenges outlined include the following: a) islands of automation and weak inter-agency information sharing, b) inadequate integration of poor citizens into e-Government, c) slow pace in multi-lingual content development due to lack of content development specialists, d) lack of empirical research to evaluate impact of e-Government on citizen livelihoods, e) privacy and security concerns and f) lack of an empirically validated model for e-Government development in Africa. In the midst of these challenges, a new wave of mgovernment has descended on South Africa. Patel (2005) acknowledges that m-Government in South Africa is in its infancy. The current m-government landscape is one of isolated pilot projects and a handful of full-scale implementations. However, there is increasing interest and acknowledgement that m-government has potential value. South Africa, in conjunction with the ITU and other cooperating partners has launched a project on Rural Telecoms, ICT Services and Entrepreneurship Development. The objective of this project is threefold: 1) to encourage telecommunication operators to provide services in rural/remote areas with appropriate private investments; 2) to foster development of the content of the ICT services
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through private public sectors collaboration; and 3) to trigger provision of services to the general public by local entrepreneurs with support from microfinance institutions and other banks (ITU, 2008). Such kinds of interventions make sure that there is chance for wireless technologies to further converge. Since e-Government, and correspondingly, m-Government are new technologies that are just being introduced, it is important to understand technology adoption theories and principles. The following section presents a discussion of technology adoption especially e-Government and briefly mentions empirical findings of initiatives aimed at encouraging technology adoption. Fan and Zhang (2006) specifically proposed a conceptual model for government to government (G2G) information sharing in the context of the e-Government environment. This was done in the spirit of reducing bureaucracy that may be evident in many government agencies (Titah and Barki, 2006). With this model, information sharing amongst different government branches was made easier. After reviewing several technology acceptance models such as the Davis’ technology acceptance model (TAM), the Diffusion of Innovation (DOI) model, the unified theory of acceptance and use of technology (UTAUT), Fan and Zhang (2006) identified 8 common factors that have been utilized in different models such as: a) perceived benefits, b) perceived risks, c) top management support, d) IT support, e) costs, f) external pressures, g) critical mass, and h) championship. These 8 factors were accordingly incorporated into a conceptual e-Government adoption model that they proposed. Kamal and Themistocleous (2006) have also conducted a study to ascertain technology adoption in a complex environment such as a local government authority with hierarchical bureacratical structures with utter commitments to outmoded cultural values. Kamal and Themistocleous have identified a set of factors from literature that influence the uptake of e-Government. These are: knowledge of technology risks, IT capabilities,
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
market knowledge on new technologies, managerial capabilities, project championships, external pressures, citizen’s data privacy and security, and Return on Investments (ROI). In their pursuit to better understand the factors that affect e-Government, Al-adawi et al (2005, P. 2), identified 4 questions they called ‘critical’ for the adoption and encapsulation of e-Government into the socio-economic setups. The following questions were identified and incorporated into a model for e-Government adoption: 1) How are intentions towards the use of e-government formed and to what extent are they related to the actual use of e-government? 2) To what extent the intentions to get information and to conduct transactions differ from each other? 3) What are the beliefs that influence citizens’ propensity to use e-government? How do these beliefs affect their intentions towards the use of e-government? 4) Are there any perception and adoption differences between segments of citizens on the basis of their technology readiness and demographic characteristics? Bélanger and Carter (2008) undertook a study which analyzed the impact of trust and risk perceptions on one’s willingness to use e-Government services and developed a model that include constructs supporting trust of the internet (TOI) and trust of government (TOG). Their study utilized data from a citizen survey that indicated that the disposition to trust positively affects TOI and TOG. Several authors (e.g. Warkentin, Gefen, Pavlou, & Rose, 2002; Bwalya, 2009; Mutula et al., 2010, and so forth) have pointed out that data security, accessibility and perceived confidentiality influence individual adoption of e-Government adoption to a greater extent. The factors affecting e-Government can be divided into individual and organizational. Titah and Barki (2006) have suggested that apart from organizational factors, individual beliefs of citizens have a significant influence on the adoption of e-Government services. With strong reference to Davis’ technology acceptance model of 1989, it is known that individual beliefs such as
perceived usefulness (PU) and perceived ease of use (PEOU) have been considered as the dominant beliefs that affect the intention to adopt or use the technology in a business to consumer (B2C) model (Warkentin, Gefen, Pavlou, & Rose, 2002). Heeks and Santos (2009; p. 3) unleashed a study where they gave some perspectives on the adoption of public sector innovations – “one that understands adoption as based on the behavior of individual actors set within a contextual framework”. Their motivation came from the fact that e-Government faces low usage rates and stated that there exists huge gaps between designers and adopters. In their study, they employed case research to study the practice-based problem of e-Government where it was thought that the experiences of the actors are important and the context of action is critical (also cited in Benbasat et al., 1987). Their study identified different factors that affect the role of the designers (as principals) and adopters (as agents). Colesca (2009) identifies five different steps to making e-Government happen and these are: Develop a vision; conduct an e-readiness assessment; identify realistic goals; get the bureaucracy to buy-in and develop a change management strategy; and build public-private partnerships. These e-Government constructs are accordingly applicable to m-Government. There is utmost need for the potential of wireless technologies to be explored as Africa’s mobile and wireless access to Internet resources keeps on growing. Boyinbode & Akinyede (2008) notes that Africa’s mobile usage has a growth rate of about 904% from 2000 to 2008 and that has made the continent the fastest growing region in terms of mobile usage. With the promising ubiquitous world, convergence of wireless technologies is very vital in that it will encourage a varying degree of e-applications to be performed on any wireless device such as mobile phone or PDA. Thus, for complete convergence to take place, as put by Javaid (2006), there are two fundamental issues: the first being the need for seamless
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Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
interoperability and pervasive integration of heterogeneous networks in order to offer a variety of diverse services in an always best connected environment, and the second being the need for optimized network resource management, which has been obstructed by the conventional wireless and cellular networks. For the case of Africa, the convergence of wireless technologies depends on the local context. The next section looks at the two cases of the role on wireless convergence as applied in the e-Government platform for Botswana and South Africa.
CASE STUDIES A) Botswana Botswana is an emerging ICT-usage-powerhouse in SSA looking at the number of interventions being implemented towards the same. Recent endeavors have seen it implement massive projects such as the construction of the Kgalagadi optical fibre network (for broadband Internet), full liberalizations of the telecommunications sector, establishment of sound ICT sector regulatory and institutional frameworks, dedicated ICT policy, setting up of Botswana IT hub, etc. In an environment like this, convergence of wireless technologies may be a reality looking at the already established appropriate ICT environment. Gillwald & Stork (2008) did a study where Botswana emerged as one of the countries with a higher fixed-line penetration with 11 to 18% of households having a working fixed-line phone. By the end of March 2002, there were 278 000 mobile subscribers as compared to 142 000 fixed line subscribers (Monnane, 2003). Compared to other countries, Botswana’s mobile penetration (teledensity) has been remarkable, from nothing in 1997 to 14.24 in 2002, only second to South Africa in the region. In terms of mobile lines as percentage of total lines, Botswana is behind Lesotho, South Africa and Tanzania only.
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With the introduction of cheap Taiwan or Chinese phones on the local telecommunications market, acquiring a handset is no longer a far-fetched dream for Botswana citizens (Batswana). Telecom operators e.g. Mascom and Orange Botswana have started offering Internet accessibility on mobile phones. People in the rural communities can also access Internet as mobile signal coverage is being improved courtesy of appropriate ICT infrastructure being erected even in rural areas as guided by the rural telecommunications initiative. This initiative has brought modern telecommunications, including Internet access, for the first time to 147 villages. When fully implemented, the project will ensure that more than 50% of Batswana living in the remote areas of the country will be provided with basic telecommunications services. Further the Botswana Telecommunications Corporation (BTC) has launched VSAT technology that, it hopes, will play a role in bringing services to remote areas through the use of satellite and overcome limitations placed on traditional services by vast distances and difficult terrain. It is anticipated that Botswana’s telecommunication industry is likely to record growth in the year 2009 placing it ahead of the telecoms market of South Africa and Nigeria in terms of teledensity. This forecast follows the launch of BeMobile by the BTC in 2008. A lot is being done in the telecoms sector to encourage the growth of this sector. Lewin et al. (2004) has noted that a Convergence Bill is under preparation to update the 1996 Telecommunications Act. Debate has focused on how far this Bill can include provisions that would extend liberalization. Another intiative has been the putting in place of the Cybercrime Bill, originally published in the Government Gazette in October 2007 (Mesa, 2007). The Convergence Bill encourages further liberalizations and convergence of both wireless and fixed technologies. Pheko (2009) notes that the effect of this has been the following: a) licensing of beMobile (the BTC mobile arm), b) rollout of product packages and price offerings to attract
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
more customers by Orange Botswana and Mascom Wireless, c) establishment of own International Voice Gateways by Mascom Wireless and Orange Botswana, d) introduction of VoIP services by PTOs and VANS; e) upgrading of Public Land Mobile networks to introduce 3G services, f) rollout of WiMax services to some urban areas and g) increase in the number of registered VANS. In order to promote adoption and acceptance of wireless technologies in the pursuit of accessing public services and exchange of information, the government and different other stakeholders such as non-governmental-organizations have put in place the following interventions: a) The Botswana Telecommunication Authority (BTA) has been formed with the mandate to coordinate the ICT and telecommunications landscape in Botswana. This includes allowing mobile Internet service providers to compete fairly with other competitors, put in place legal and institutional frameworks, and so forth. b) About 4% of the country’s GDP has been directly allocated to interventions to encourage use of ICT (Mutula et al., 2010). These interventions include, among others. Carrying out massive awareness campaigns to the general citizenry on the benefits of taking full advantage of ICT platforms to access government services and participate in decision-making. Out of these awareness campaigns, many people now understand the importance of computers in their lives. c) Subsidizing computer and mobile gadgets importation into Botswana and reduction in duty paid for computer accessories into Botswana. d) Government’s implementation of Thuto.net project which aims to encourage the penetration of computers and mobile technologies (especially mobile phones) into Botswana’s schools, universities and companies. Out of this initiative, all the universities and schools
have computers and computer awareness courses have been introduced in all the high countries throughout the country. e) The BTA is also mandated to protect the consumer from exposure to harmful digital content by making sure that acceptable security is implemented to digital resources by the producers. f) The government further sponsors radio talks on how public services can be accessed through ICTs (e-Government). g) Establishment of an e/m-Government task force that has been mandated to make sure that the implementation of the e-Government agenda is realized. This e-Government task force is house within the Ministry of Transport and Communication under the Department of Information Technology. The task force has so far come up with a draft e-Government strategy for Botswana, and is currently working hand-in-hand with BTA to make sure m-Government applications are made a reality. To this end, a government portal has been designed and is in its pilot phase awaiting commissioning after considerable feedback from the users has been obtained. Feedback from the users of the limited mGovernment initiatives that are in place suggest that although many people are not directly aware of e-Government interventions and benefits, there are positive signs that m-Government will thrive in Botswana. Given these scenarios, it is fair to state that there is a lot of potential of m-Government in Botswana (Mutula et al., 2010) as more and more people are having access to mobile phones which can further be used as platforms for Internet access.
B) South Africa South Africa has done some significant strides in taking advantage of what convergence of wireless
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Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
technologies has to offer by putting in place a committed team for m-Government implementation (Maumbe & Owei, 2006, 2009). Although there are challenges that have been met, use of the m-Government model in South Africa presents a promising platform for citizen-governmentbusiness interactions. Between 2003 and 2008, there has been over 40% increase in the number of mobile subscribers per 100 population in South Africa (Du Preez, 2009). The phenomenal growth in mobile subscribers has been coupled by a rapid increase in commercial and other e-applications that take advantage of the ubiquitous nature of mobile phones. With its relatively well developed and diverse infrastructure, South Africa is taking a regional lead role in the convergence of ICTs with the media and entertainment sector, promising reductions in telecoms costs and better availability of information and services. Billions of dollars are being invested into IP-based Next Generation Networks that are capable of delivering converged services more efficiently (Research report, 2009). Telecom carriers and ISPs are moving into delivering audio and video content over their networks, while in turn the traditional electronic media carriers are discovering the potential of their infrastructure for telecommunications service delivery. Mobile TV licenses are expected to be issued in 2009. Graham et al. (2003) further stipulates that the South African telecommunications market is poised at a critical point in its development. On the wireless side, South Africa has witnessed a spectacular growth in users, far beyond original expectations. Despite high levels of income inequality, approximately 37 percent of South Africans now have a mobile phone (Du Preez, 2009). Whether through WAP-based applications on mobile phones or via cellular data cards connected to laptop computers, wireless technology will increase Internet usage, and will drive some convergence with the fixed Internet world (Graham et al., 2003). South Africa presents a case
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where convergence is taking place not only in the wireless medium, but blended convergence between broadcast services and mobile communications. This type of convergence is opening way for the implementation of mobile and digital TVs which will impact the way people consume digital content. South Africa’s public sector institutions largely engage with mobile solutions in an isolated and case-specific manner. There is no comprehensive strategy guiding choices around the use of mobile technology. Trying to take advantage of what the convergence of wireless networks has to offer, South Africa has put in place a well-defined vision for e/m-Government. The m-Government strategy, being driven by the South African Center of Excellence on m-Government, will ensure that the public sector can use its spending power and leverage far more strategically, and hence extend access to services whilst the Centre of Excellence will provide a meeting place where government and the private sector can, on a on-going basis, identify and test m-Government solutions as well as to look at how these solutions can positively contribute to improved operations and public service delivery (Maumbe, 2006; Du Preez, 2009). Maumbe and Owei (2006) analyzed the status of m-Government implementation in South Africa. In their study, they carried out an information audit on what endeavors have been done in the line of m-Government implementation, identified the different factors that affect e-Government implementation and developed a model for m-Government implementation in South Africa (please refer to Maumbe and Owei, 2006). Another study by Du Preez (2009) assessed the m-Government readiness in the province of Western Cape. That study found out that countrywide, there are more than 30 million mobile services subscribers and that Western Cape presents a case where mobile technology is going to be used as a major e-Government platform in future. Many of the participants in that survey gave positive experiences with regards to mobile technolo-
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
gies and m-Government. The major limitation identified in both studies by Maumbe /Owei and Du Preez point to limitation of public services that can be decoded on mobile platforms. Most public services require a considerable bandwidth to access major applications.
SOLUTIONS AND RECOMMENDATIONS Botswana and South Africa show a case where different stakeholders are committed to advancing the wireless technologies for e-Government applications. This is evidenced by different institutional and regulatory frameworks that have been set up starting from the liberalization of the telecommunications sector. Both countries have put in place an enabling environment for wireless technologies proliferation. However this being the case, there are several challenges that are faced in both cases concerning benefits for the transformation of convergence of wireless technologies into tangible socio-economic values and e-applications such as m-Government. These challenges may be different from context-to-context. The following list shows the general recommendations that should be considered when implementing m-Government applications. Looking at the cases presented above, it is evident that there are still some issues that need to be addressed before m-Government were to be a success or mean anything tangible to the ordinary citizens of both South Africa and Botswana. Whilst major interventions are being implemented in both countries, it is evident that not much is being done in regards to protecting the user in these m-Government environments. a) Encourage and nurture m-Government applications by further encouraging awareness campaigns on mass scales to educate people on the benefits of engaging in m-Government applications. These campaigns should be
directed at highlighting both the pros and cons of engaging in m-government. The strategy taken by Botswana in strengthening radio e-Government campaigns should be encouraged. In fact, these campaigns can even be replicated to being promoted using simple text messages pointing citizens to where e-Government services can be found on the cyber space. b) Engage more of Wireless Application Service Providers (WASPs) in pushing the convergence of wireless technologies agenda. This is because some government entities may not have the technical staff and capacity to support the required programming and deployment to link applications to multiple types of wireless devices. For both South Africa and Botswana, this can be done through the regulatory bodies. The regulatory body in respective countries can engage the telecommunications service providers to provide their services through common wireless platforms and technologies. Further, these bodies can also help in encouraging the understanding and adoption of m-Government by ordinary citizens. c) There should be efficient liberalization platforms that encourage competition in the telecoms sector. The more service providers, the more competition and the better the services provided become. This may have a direct impact on m-Government. These liberalization plans should also be spearheaded by the regulatory bodies (BTA for the case of Botswana). d) The future importance of m-Government in the service delivery agenda will be dependent on resolving a range of range of technical and non-technical issues and challenges which are context-specific as identified in this chapter. This should be done through closer cooperation between industry and government, and not forgetting ordinary citizens. It is to be mentioned that a consul-
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Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
tative process in drawing any strategy for m-Government is desired. Both South Africa and Botswana have put in place teams driving the e/m-Government agenda and drawing up / refining existing e/m-Government roadmap. It is desired that an e-Government agenda done in a participatory manner is appropriate because it can install a sense of ownership into the people and thus they can easily buy in into the technology. e) It is not only with putting in place institutional and regulatory frameworks that can make m-Government to thrive. Developing a better understanding of the legal and institutional issues that facilitate m-Government deployment and addressing weaknesses that may exist is also equally important. Such kind of initiatives should be embedded into e-Government strategy. f) There is a need to introduce an appropriate partnership between network operators, citizens, public sector institutions, and application developers (locally bred) that would allow for the identification of possibilities of the technology for government where this is cost effective and efficient. Once these set of recommendations are considered, coupled with other technical and managerial issues that may affect a local context have been taken care of, it is anticipated that the likelihood that the convergence of wireless technologies will bring forth m-Government success is high.
FUTURE RESEARCH DIRECTIONS The convergence of wireless technologies to presenting a better platform for m-Government summons a number of issues and challenges if full value of these technologies were to be retrieved. Wireless technologies are still under an active developmental phase so technical issues such as security and data rates are still in their infancy
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of investigations. Most commonly used security platforms such as the wireless intrusion prevention system (WIPS) which monitors the radio spectrum for the presence of unauthorized access points (intrusion detection) and can automatically take countermeasures (intrusion prevention) may have several limitation concerns. Also, devices such as WIPS may not be cheaply accessible to ensure secure application in wireless technologies which would further install confidence on the part of m-Government participants. Further research directions should concentrate on finding cheap, yet appropriate security platforms that can be used in wireless technologies especially as these technologies converge. Also, it is imperative that future research directions be devoted towards finding optimal solutions to the following problems: a) The lack of technical professionals to develop applications, services and contents to increase the ROI for operators with great value solutions adapted to the need of population in the different countries. b) The computer penetration in home and companies and the need of develop an Internet culture to prepare the future citizens which demands new technologies like basic tools for the Society. This entails finding appropriate technology adoption models commensurate to the African technological setup. Other research directions include finding a synergy on how different evolving technologies can be made to perform common e-applications in the name of convergence. These may include further investigating both technical and managerial issues from an African perspective of convergence between broadcasting and telecommunications, fixed and wireless networks/services and voice and data networks. Further work is also needed to accommodate the different stakeholders that utilize e/m-Government applications in the same harmonized e-applications environment.
Convergence of Wireless Technologies in Consolidating E-Government Applications in Sub-Saharan Africa
CONCLUSION Evolving technologies and the convergence of different wireless technologies present a chance that ICT can be used as a public good in facilitating e-applications such as e-Government. Wireless technologies have provided a platform which offers mobility to different ICT devices. As these devices’ capacity to access the Internet is enhanced, and as this presents one of the fastest growing technologies adopted in Africa, the mGovernment model has been made possible. The opportunity provided by m-Government comes with many issues and challenges according to the context where this e-Government model is being implemented. This chapter has looked at what convergence of wireless technologies is and what it entails. Botswana and South Africa have been presented as case studies to ascertain the status of encapsulation of wireless technologies into the m-Government model. The chapter has shown that convergence of wireless technologies is occurring at different levels within the vertical value stack, from networking technology, services and applications to end-user mobile terminals. The chapter has also outlined the different interventions and actions that are necessary for effective convergence to take place and which should be focused on if different stakeholders such as the industry players and regulators are to benefit from the full range of opportunities that are and will be presented by the wireless industry now and in the future. The general consensus of this chapter is that since mobile and wireless technologies have shown great signs of growth in Africa, it is vital that the benefits (such as enhancing e-applications on heterogeneous mobile ICT devices) that this has to offer are taken advantage of. For this to be realized, the different challenges that come with convergence of different wireless technologies, especially for the case of Africa, have to be taken care of. M-Government (which is a replica of eGovernment but with the case where the ICTs used
are not static and where e-Government is mostly accessed using mobile technologies allowing a great deal of ubiquity and pervasiveness) has shown a lot of potential in Africa given the higher costs in acquiring standard computers and higher costs for Internet access which are prerequisites for e-Government facilitation. M-Government, however, offers a flexible and affordable platform as people can access the Internet for interaction with different m-Government stakeholders anytime and anywhere. For the case of typical e-Government, Internet access is only possible on static computers and the Internet provided by ISPs may be expensive than one provided by telecom companies on mobile devices. Now that m-government is inevitable, extending activities to wireless devices and networks will enable SSA countries to be more proactive in their operations and services by providing realtime and up-to-date information to the officials on the move and by offering citizens a broader selection of choices of interactions.
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Karantjias, A., Papastergiou, S., & Polemi, D. (2007). Innovative, Secure and Interoperable E/MGovernmental Invoicing. Paper presented at the 18th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2007). IEEE. 1-5, 3-7. Retrieved September 13, 2007 from http://ieeexplore.ieee.org/stamp/stamp. jsp?arnumber=4394010&isnumber=4393983 Kushchu, I., & Kuscu, M. (2003). M-Government: facing the inevitable. Paper presented at the 3rd European Conference on e-Government, Frank Bannister and Dan Remenyi (eds.), Trinity College, Dublin Ireland. Lanwin, B. (2002). A Project of Info Dev and The Center for Democracy & Technology. The E-government handbook for developing countries. Retrieved November 15, 2009, from http://www. cdt.org/egov/handbook/2002-11-14egovhandbook.pdf Lewin, D., Hall, R., & Milne, C. (2004). Further liberalization of Botswana’s telecommunications industry. Consultation document for interested parties issued by the Botswana Telecommunications Authority. Retrieved August 8, 2009, from www. bta.org.bw/pubs/Liberalisation%20Consult2.pdf Maumbe, B. M., & Owei, V. (2006). Bringing M-government to South African Citizens: Policy Framework. Cape Town: Delivery Challenges and Opportunities. MESA IT&T Newsleter, fourth quarter. (2007). Retrieved August 17, 2009, from http://www. linexlegal.com/content.php? Monnane, M. (2003). Botswana Telecommunications Services. Southern African Trade Research Network (SATRN). Working Paper No. 3 Mutula, S., Grand, B., Zulu, S., & Sebina, P. (2010). Towards an information society in Botswana: ICT4D Country Report. Research paper presented at Thetha Sangonet ICT4D Forum.4
Odinma, A. C., Oborkhale, L. I., & Kah, M. O. (2007). The Trends in Broadband Wireless Networks Technologies. The Pacific Journal of Science and Technology, 8(1). Retrieved June 25, 2009, from http://www.akamaiuniversity.us/PJST.htm. Patel, I., & White, G. (2005). M-government: South African Approaches and Experiences. Paper presented at EURO mGOV 2005, Brighton, UK, 313-323. Pheko, T. G. (2009). Botswana Telecommunications Authority. Botswana Country Report to CRASA. Retrieved August 15, 2009, from www. crasa.org/.../reports/.../Botswana%20Report%20 2009%20Presentation.pdf ITU Report. (2008). Report on the World Summit on the Information society stocktaking. Research Report. (2009). South Africa – Convergence – VoIP, NGN & Digital Media. Retrieved June 22, 2009, from http://www.researchandmarkets. com/reports/1031255/ Rossel, P., Finger, M., & Misuraca, G. (2006). Mobile” e-Government Options: Between Technologydriven and Usercentric. The Electronic [from www. ejeg.com]. Journal of E-Government, 4(2), 79–86. Retrieved September 20, 2009. Titah, R., & Barki, H. (2006). E-Government adoption and acceptance: A literature review. International Journal of Electronic Government Research, 2(3), 23–57. Touré, H. I. (2006). Competitiveness and Information and Communication Technologies (ICTs) in Africa International Telecommunication Union. Retrieved July 12, 2009, from www.weforum.org/ pdf/gcr/africa/1.5.pdf TRASA report. (2009). Report on the Next Generation Wireless Technologies Conference for Southern Africa. Retrieved August 4, 2009, from www.crasa.org/.../Next%20Generation%20Conference%20Report.pdf
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Wangpipatwong, S., Chutimaskul, W., & Papasratorn, B. (2008). Understanding Citizen’s Continuance Intention to Use e-Government Website: a Composite View of Technology Acceptance Model and Computer Self-Efficacy” The Electronic [from www.ejeg.com]. Journal of E-Government, 6(1), 55–64. Retrieved September 7, 2009. Warkentin, M., Gefen, D., Pavlou, P., & Rose, G. (2002). Encouraging citizen adoption of E-Government by building trust. Electronic Markets, 12(3), 157–162. doi:10.1080/101967802320245929
KEY TERMS AND DEFINITIONS Wireless Technologies: Technologies that enable communication to be facilitated through wave propagation with no use of a wired medium. The wave propagation may happen between a stationery base station or access node and a mobile platform such as a PDA. Convergence: Is the approach toward a definite value, a definite point, a common view or opinion, or toward a fixed or equilibrium state. Convergence of wireless technologies means different wireless technologies such as WiFi and WIMAX can decode encoded signals from the same base station either WiFi or WIMAX technology.
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Electronic Government (e-Government): Is a platform through which the government interacts with its citizens and business entities for the sake of exchange of information, public services and participatory democracy through the use of ICT platforms. Mobile Government (m-Government): This is replica version of e-Government, only that in this mode, mobile ICT devices are used for interactions and access to the Internet may be facilitated anywhere and anytime (ubiquitous nature of e-Government). ICT: This acronym stands for information and communications infrastructure. Sub-Saharan Africa (SSA): Is a geographical term used to describe the area of the African continent which lies south of the Sahara or those African countries which are fully or partially located south of the Sahara. This excludes North African countries because they are considered as belonging to the Arab world. ICT Infrastructure: It encompasses all the devices, networks, protocols and procedures that are employed in the telecoms or information technology fields to foster interaction amongst different stakeholders. Regulatory Framework: A set of guidelines that coordinates the following of set principles, e.g. market competition and liberalization, ethic, etc.
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Chapter 5
Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs:
Absorptive Capacity Limitations Kathryn J. Hayes University of Western Sydney, Australia Ross Chapman Deakin University Melbourne, Australia
ABSTRACT This chapter considers the potential for absorptive capacity limitations to prevent SME manufacturers benefiting from the implementation of Ambient Intelligence (AmI) technologies. The chapter also examines the role of intermediary organisations in alleviating these absorptive capacity constraints. In order to understand the context of the research, a review of the role of SMEs in the Australian manufacturing industry, plus the impacts of government innovation policy and absorptive capacity constraints in SMEs in Australia is provided. Advances in the development of ICT industry standards, and the proliferation of software and support for the Windows/Intel platform have brought technology to SMEs without the need for bespoke development. The results from the joint European and Australian AmI-4-SME projects suggest that SMEs can successfully use “external research sub-units” in the form of industry networks, research organisations and technology providers to offset internal absorptive capacity limitations.
INTRODUCTION Through case study research, this chapter discusses some of the challenges Small and Medium Enterprises (SMEs) in the manufacturing sector face DOI: 10.4018/978-1-60960-042-6.ch005
in identifying and adopting Ambient Intelligence (AmI) technologies to improve their operations. Ambient Intelligence technologies are also known as Pervasive computing or Ubiquitous computing, and we include the descriptions of these terms when we refer to AmI technologies. Our study includes case studies of three Australian
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
SMEs and a comparison with similar application requirements in a German SME manufacturer. The outcomes of the study are likely to be applicable to small firms in many nations. The 1980s and 90s saw the operations of many large manufacturers revolutionized by the introduction of process and technological innovations (Gunasekaran & Yusuf, 2002). While there have been uneven adoption rates in smaller businesses and across different nations (Chong & Pervan, 2007; Oyelaran-Oyeyinka & Lal, 2006) it is clear that technological innovations such as Electronic Data Interchange, Business Process Re-engineering, Enterprise Resource Planning and robotic automation, amongst others, have played key roles in increasing manufacturing productivity. At the beginning of the twenty first century this transformation continues. Ambient Intelligence (AmI) technologies are being positioned as the next performance and productivity enhancing purchase for manufacturers, and a potential means for manufacturers in developed nations to counter perceived threats from lower labour cost countries (Kuehnle, 2007). Thus, the key objectives of this chapter are to consider potential applications of AmI technologies in Australian SME manufacturers, and discuss the opportunities and shared challenges faced by such firms in adopting these technologies. In doing this we will compare different levels of absorptive capacity and technological readiness in Australian firms, seeking possible reasons for similarities and differences in their comparative technology adoption processes. The chapter also examines the role of intermediary organisations in alleviating these absorptive capacity constraints. Our overarching research question is: “Can external intermediaries overcome absorptive capacity limitations in SMEs seeking process innovation through the application of AmI technologies?” In order to understand the issues surrounding this problem, a brief overview of ICT (Information and Communication Technologies) adoption in
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manufacturing and an explanation of Ambient Intelligence (AmI) technologies are provided in the following section. Following that we examine the role of SMEs in the Australian manufacturing industry plus the impacts of government innovation policy and absorptive capacity constraints in SMEs in Australia.
BACKGROUND ICT Adoption for Business Performance Improvement Brown and Bessant (2003) described the global manufacturing environment developing in this new century as an increasingly competitive landscape, characterised by on-going demands for improved flexibility, delivery speed and innovation. A frequently occurring element in manufacturers’ responses to these pressures is the implementation of increasingly sophisticated ICTs. The benefits of incorporating ICTs on business responsiveness have been identified as: more effective and more efficient information flows; assisting in value-adding improvements for current processes; greater access to efficiency enhancing innovations throughout the value chain (Australian Productivity Commission, 2004); and the ability to access world markets through e-commerce (Kinder, 2002). ICT adoption has been considered worth the risk, given the competitive pressures placed on business to keep pace with technology. For example, in Australia, the uptake of ICTs has increased dramatically towards the later part of the 90’s and into the 21st Century. Reports show that in 199394, 50 per cent of firms used computers with 30 per cent having internet access; by 2000-01 these figures had increased to 85 per cent and 70 per cent respectively (Australian Productivity Commission, 2004). Recent figures (Australian Bureau of Statistics, 2009) reveal that almost all Austra-
Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
lian SMEs use ICTs, and 96% of them access the internet through a broadband connection. One of the latest developments in the application of ICTs to business improvement is that of Ambient Intelligence (AmI) technologies. The objective of AmI is to broaden and improve the interaction between human beings and digital technology through the use of ubiquitous computing devices. By using a wider range of simplified interaction devices, ensuring more effective communication between devices (particularly via wireless networks) and embedding technology into the work environment, AmI provides increased efficiency, more intuitive interaction with technology (Campos, Pina, & Neves-Silva, 2006) and improved value and productivity (Maurtua, Perez, Susperregi, Tubio, & Ibarguren, 2006).
Ambient Intelligence (AmI) Technologies Existing literature (Kopacsi, Kovacs, Anufriev, & Michelini, 2007; Li, Feng, Zhou, & Shi, 2009; Maurtua et al., 2006; Vasilakos, 2008; Weber, 2003) points to the co-existence of three features in any AmI technology: ubiquitous computing power, ubiquitous communication and adaptive, human-centric interfaces. Regardless of arguments about terminology and definitions (the terms “pervasive computing” and “ubiquitous computing” are in common use in the US, while “ambient intelligence” is favoured in the EU), these technologies are already commonplace. The beep signalling the automatic deduction of a road toll from your account as your car passes under a toll gate is one aspect of an AmI technology known as Radio-Frequency Identification (RFID). RFID technology is having an impact in many industries, some of which are not normally associated with high levels of ICT adoption. For example, during 2006, in NSW alone (one of the 7 states and territories within mainland Australia), more than 1.2 million head of cattle were automatically
tracked from farm to saleyard to abattoir as their RFID ear tags passed through RFID sensor gates (NSW Farmers Association, 2007). In addition to increasing process speed and efficiency, AmI technologies have the potential to provide tracking of employee and customer activity. While concerns about the impact of technology upon power relations in the workplace are not new (Zuboff, 1988), the characteristics of AmI technologies present new challenges to worker privacy, informed consent and dignity. AmI technologies may, intentionally or not, dramatically increase employee surveillance and monitor consumer activity over the entire product life cycle. This potential and the very nature of ‘ubiquitous computing’ raises important ethical issues. Proposals to use RFID tags to track sufferers of Alzheimer’s disease (Caprio, 2005) and children provide examples of the ethical dilemmas AmI technologies can present. While these issues are beyond the scope of this chapter, we suggest Cochran et al (2007) for a review of ethical challenges associated with RFID. Social factors associated with the introduction and implementation of AmI technologies may be exacerbated in small and medium businesses. In addition to concerns shared with corporate workers, such as disquiet about their personal data potentially being sold to marketing groups and anxiety about the security of the information gathered, members of small businesses are particularly prone to AmI’s ability to ‘break the boundaries of work and home through their pervasiveness and ‘always on’ nature’ (Ellis, 2004, p.8). While some profit-maximising small business owners welcomed this blurring of work and home boundaries, others did not, preferring to keep work and family spheres separate. Ellis cautions that in order to overcome existing negative preconceptions of AmI technologies, users must feel they control the devices and the data they produce, and be able to override them and cope with systems failure. In particular, AmI needs to be presented
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
as “smarter” than existing ICTs and able to correct some of the problems associated with traditional forms of ICT support. In short, Ellis (2004, p. 9) asserts, “AmI needs to be associated with undoing some of the more problematic aspects of existing ICTs, to be accepted and not resisted as a more invasive, insidious and controlling form of what already exists.” Much of the promise of Ambient Intelligence (AmI) technologies rests upon connecting increasingly sophisticated and powerful sensors with existing computing facilities. McCullough (2001) identified the need to expand our thinking beyond the notion of filling environments with physical objects when considering Ambient Intelligence technologies. There is no longer such a thing as “empty space” when sensors and processing power combine to produce an environment that is “aware” of the locations, actions and information needs of humans. Clearly, the extent of existing Information and Communications Technology (ICT) infrastructure in an organisation will impact AmI technology implementations, providing either a “clean slate” from which to start or the opportunity to integrate new AmI capabilities with existing ICT systems and processes. In much the same way as the advent of mobile phones in China and India provided an opportunity for people unable to afford a landline, to access telephonic services, AmI technologies may prove a way for SME organisations to “leap frog” a stage of ICT implementation, and move directly to wireless and similar AmI technologies. Many other applications of AmI technologies are appearing as technologists extend the concept into areas such as “wearable technology” (clothing that incorporates sensors and interface devices), more intuitive home space designs, shopping assistance and the creation of seamless interfaces between work, home and leisure activities. While many of these applications currently seem unrelated to improving business productivity, it is clear that the applications for business can only grow as the technologies become more sophisticated and
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less expensive. As Rao and Zimmerman (2005, p.3) state “there is a gap in the scholarly discussion addressing the business issues related to it, and the role of pervasive computing in driving business innovation”. It is in this context that the following case studies of four small-to-medium (SME) manufacturers - three Australian and one German firm – have been undertaken. In each firm, critical process analysis was carried out to examine possible process weaknesses and existing ICT systems, and recommendations were made concerning a selection of AmI technologies with the potential to boost business performance.
AMBIENT INTELLIGENCE TECHNOLOGY IN MANUFACTURING This section considers the applicability of several emerging AmI technologies to three SME manufacturers in New South Wales, Australia and compares the situation within these SMEs with one German SME manufacturer undertaking a similar technological adoption. In doing this the section also addresses questions about the preparedness of SMEs, particularly concerning their absorptive capacity limitations and how these may be overcome. Later sections also consider the potential impact of Ambient Technologies on the employees of the organisations studied. AmI technology is much more than RFID inventory control systems. Wireless, multi-modal services and speech recognition systems have the potential to increase manufacturing flexibility by supporting dynamic reconfiguration of process and assembly lines, and improving human-machine interfaces to reduce process times (Maurtua et al., 2006). Also, maintenance and distribution processes may be improved by linking common mobile wireless devices, such as mobile phones, Personal Digital Assistants (PDAs) or even pagers to production alert systems (Stokic, Kirchhoff, & Sundmaeker, 2006).
Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
Small and Medium Manufacturers in Australia Organisations with between 20 and 199 workers employ 56% of Australia’s workforce (Wiesner, McDonald, & Banham, 2007). The Australian Bureau of Statistics (ABS) defines a small business as employing less than 20 people, and a medium enterprise as employing between 20 and 200 employees (ABS, 2001). The most recent ABS figures available (2007) for Australia indicate that there are around 47,000 manufacturing firms employing between 1 and 20 people, around 10,000 employing between 20 and 200 people, and only 873 employing over 200 people. In turnover terms, around 29,000 manufacturing firms reported annual turnover between $500,000 and $10 million, while only 3,300 firms reported turnover of $10 million or above. It is clear that the bulk of manufacturing in Australia occurs in small-to medium firms. While SME firms employ the majority of manufacturing workers their expenditure on R&D notably lags behind that of large manufacturers. Within the manufacturing industry companies with more than 200 employees were responsible for 73% of total industry R&D expenditure, with only 27% being contributed by the SME sector (ABS, 2007). However, in their exploration of the cost and impact of logistics technologies in US manufacturing firms Germain, Droge & Daugherty (1994) found that for manufacturing managers wanting to innovate with logistics technology, organisational size provides an advantage that transcends both the cost and nature of the technology. These authors confirmed the established view in 1994; that organisational size was positively correlated with technology adoption, as found in many previous studies. This link between manufacturing organisation size and increased ability to extract benefit from technological innovations may provide some explanation for the fact that while Australia’s manufacturing output has quadrupled since the mid 1950s, the Australian Government
Productivity Commission (2003) states that overall, it has not grown at the same rate as the service sector. The Productivity Commission also describes Australia’s manufacturing sector as having “missed out on the productivity surge” of the mid 1990s while noting signs of improved manufacturing productivity in 2002 and 2003. The widespread availability of off-the-shelf ICT systems has probably meant that a great many more SMEs are adopting ICTs today than in 1994, however the limited resources of many such firms (both financial and human) almost certainly mean reduced awareness and limited capacity to exploit newer technologies commonly appearing in larger manufacturers. Given the significance of SMEs in Australian employment and the perceived need to increase manufacturing productivity, examination of the potential improvements available through the systemic application of AmI technology to SME manufacturers forms an important topic for research and government policy.
Absorptive Capacity This chapter applies the concept of absorptive capacity to manufacturing SMEs. We argue that SMEs can benefit from AmI technologies, using specialised intermediary organisations to overcome the “absorptive capacity” limitations evident in many SME organisations. Cohen and Levinthal (1990) proposed that internal Research & Development activities serve two purposes: to generate innovations, and to provide the ability to absorb relevant knowledge appearing in the external environment. The absorptive capacity of a firm is comprised of these two categories of activity. Their foundational paper conceptualised absorptive capacity in the context of large U.S. manufacturers, as evidenced by their survey of identifiable “R&D lab managers” (Cohen & Levinthal, 1990, p. 142) and their discussion of “communication inefficiencies” between business units. But what of small- and medium-sized manufacturers? Does the notion of absorptive
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
capacity have relevance to SMEs outside narrow, industry-segment specific technologies? If so, can external intermediaries assist SMEs to overcome absorptive capacity limitations regarding ambient technological innovations? The preparedness of SMEs to adopt and benefit from the mobile capabilities of AmI technologies is likely to be linked to their ability to overcome the limited absorptive capabilities associated with their small size. However, it is possible for SMEs to successfully deploy AmI technologies. Clear evidence of the benefits produced by a range of AmI technologies have been observed by the researchers at Costa Logistics’ distribution centre in Western Sydney. Costa Logistics specializes in the distribution of fresh fruit and vegetables, and achieves astounding levels of accuracy and throughput: staff average zero to three errors per million cartons picked in the warehouse, the daily inventory turn ratio is 100% and over A$2 billion of product is handled annually on behalf of their clients (Game-Lopata, 2008). The company was a SME when it started to use wrist-mounted bar-code scanners coupled with wireless communications. These successfully implemented AmI technologies are key factor that have enabled Costa Logistics rapid expansion to well over 200 employees in late 2009.
Innovation, Manufacturers, SMEs and Government Policy Several previous studies (Cutler, 2008; Philips, 1997) have concluded that innovative Australian firms of all sizes (both manufacturing and servicebased) tend to be more successful in terms of sales growth and market share than non-innovating firms. In addition, the impact of innovation is considered to be cumulative (Chapman, Toner, Sloan, Caddy, & Turpin, 2008) with some level of innovative behaviour or research and development being required to equip a firm to identify, assess and adopt technologies. The innovativeness and absorptive capacity of SMEs is a matter of concern for other nations besides Australia. For example,
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in its 2008 budget, the UK government signalled its intention to set a goal for innovative SMEs to win 30% of its ₤150 billion public procurement spending (Kable’s Government Computing, 2008), equating to $98 billion (AUD) of incentives to encourage UK SMEs to innovate. While similar incentives are yet to appear in Australia, there are clear signs of government interest in the ability of SMEs to innovate (Department of Innovation Industry Science and Research, 2008). There is a growing body of work in the innovation literature on the limited absorptive capacity of SMEs to identify relevant innovations, understand and appreciate possible applications, and finally adapt and implement innovation in their organisations (Beckett, 2008; Liao, Welsch, & Stoica, 2003; Muscio, 2008). Many points concerning “constraining factors” and “implementation challenges” support the notion that SMEs can experience organisational absorptive capacity limitations. Beckett (2008) identifies knowledge and resource constraints that impede the ability of SMEs to develop absorptive capacity, but also provides an example of how absorptive capacity is built when the outlays of time and money required match the SME’s available resources. While the benefits of AmI technologies are already accruing in large organisations (Angeles, 2005) if manufacturing SMEs are to benefit from AmI technologies, one challenge requiring attention will be that of their limited absorptive capacity for technological innovations. Our research considered the possibility of external intermediaries being used to facilitate SME manufacturers’ assessment of the application of AmI technologies for process innovation, thus overcoming, at least partially, the problems of limited absorptive capacity within the partner SMEs.
Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
Figure 1. Representation of the Three Phase AmI-4-SME Methodology (Source (Kirchhoff et al., 2006))
METHODOLOGY AND DATA COLLECTION Case research has been used to review and compare the operations of the three NSW manufacturing SMEs, identify process weak points (in partnership with the SME executive managers) and suggest potential Ambient Intelligence Technologies to assist each organisation. The data has been gathered as part of an Australian government funded International Science Linkages Project, which in turn was part of a larger EuropeanAustralian project on Ambient Intelligence in manufacturing - Ambient Intelligence Technology for Systemic Innovation in Manufacturing SMEs (AmI-4-SMEs). The European component of the AmI-4-SMEs project involved six SMEs, three research partners and three Information and Communications Technology (ICT) providers located in Germany, Ireland, Spain and Poland. The Australian AmI-4-SMEs project consists of six SMEs, two research partners (University of Melbourne and University of Western Sydney) and two ICT providers. Six SMEs were selected from those responding to a request for expressions of interest in participating in the study. Using the Australian Bureau of Statistics metrics (2001), all are classified as small-to-medium sized manufacturers and all are privately owned.
The EU AmI-4-SMEs project aimed to design and develop a coordinated approach for process innovation using, ICT “building blocks” and a software platform to support the improvement of manufacturing processes in SMEs. These improvements were achieved by re-engineering processes and introducing appropriate ICT tools. The method used to analyse and re-engineer business processes is an extension of the COST-WORTH methodology (ATB Institute for Applied Systems Technology Bremen GmbH, 2004) and has three main phases: Analysis and Conception, Selection and Specification, and finally Implementation. Due to lower levels of government funding support, the Australian Ami-4-SMEs project performed only the Analysis and Conception, and the initial aspects of the Specification and Design phase but not the Implementation phase. The links between these phases are shown in Figure 1. The Analysis and Conception phase produces an implementation plan for the proposed AmI solution. Analyses of each SME’s business processes and bottlenecks form the majority of this phase which concludes with presentation of a business re-engineering recommendation and a Return on Investment Analysis (Kirchhoff, Stokic, & Sundmaeker, 2006). One challenge of working with SMEs is to gather sufficient information without intruding
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
to the extent that the organisation is adversely affected. On-site interviews and observation, questionnaires (these were developed as a part of the precursor COSTWORTH project, see Nousala, Ifandoudas, Terziovski and Chapman, 2008), video recordings, a visit to a company (Costa Logistics) already using wireless, wearable and voice (Chang & Heng, 2006) technologies in its warehouse, and joint creation of process maps where they did not previously exist were used to collect data and minimise disruption to the SMEs. Interview and questionnaire data were used to select important, problematic processes for each SME. On-site observations and video recordings were analysed to create “as-is” maps of the process selected for improvement, and identify key limitations of each process. AmI technologies with potential to improve the selected business process were selected and the likely costs and benefits reviewed with the SME executive managers. A strength (and simultaneous limitation) of this approach, is that the time spent at each SME site is not extended or intensive. However, given the objectives of the analysis and conception phase of the AmI-4-SMEs project, and the need to minimise disruption to the operation of the manufacturing businesses, the methods are appropriate.
RESULTS
have been used for the SME companies. Ranked in order from low to higher technological capability they were: SwivelMould – a plastics manufacturer specialising in rotational moulding work; BottleTop – manufacturer of plastic packaging closures; and TechMakers – a contract electronics component manufacturer. As described in the methodology section, due to lower funding levels, the Australian AmI-4SMEs project did not fully incorporate the latter two phases of the project (see Figure 1), instead leaving it to the individual companies to complete these steps. The European project funding also included direct funding support for the SME partners, which was not provided under the Australian government support funds. However, the Analysis and Conception phase, and the initial aspects of the Specification & Selection phase, included a detailed initial assessment of each SME, identified possible AmI solutions and produced a rough implementation plan for the proposed AmI solution. Analyses of each SME’s business processes and bottlenecks formed the majority of this phase, and these were conducted on-site at the three NSW SMEs. Tables 1 and 2 present summary information and key issues related to technology adoption for each of the three SMEs from New South Wales, Australia.
Overview of the Three Australian SMEs
Similarities and Differences between the Three Australian SME Manufacturers
The three Sydney-based SMEs represent a wide range of existing ICT complexity and skill, from “craft-work” factories to highly sophisticated manufacturers of technology. Although the organisations were not intentionally recruited to represent a typology of low, moderate and highly integrated ICT installations and skill sets, they do display these characteristics and it is useful to consider how AmI technology capabilities may be added to each of these settings. Pseudonyms
Scalability issues related to specialised equipment appeared as a limitation shared by the three Australian SMEs. Production could not rapidly increase without the purchase of more machinery, and in the case of TechMakers, difficulty in arranging for the rapid importation of components also limited their growth. Key differences observed in the three Australian SMEs relate to the proportion of standardised production and organisational culture. Eighty per
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
Table 1. Company summary BottleTop Turnover: $30M Employees 97 Profit: moving from break-even to profitable trading in 2008/09. Industry: Manufacturing of packaging closures Outlook: Growing in a shrinking market by taking market share from competitors. BottleTop has set an aggressive revenue growth target of $50M by 2011/12.
TechMakers Turnover: $7 M Employees 70 Profit: Trading profitably Industry: Contract Electronic Manufacturers. Outlook: Industry is shrinking, work is increasingly being sent off shore, TechMakers are diversifying by creating and selling the devices they created to assist in their contract electronic manufacturing activities.
SwivelMould Turnover: $20M Employees: 80 Profit: trading profitably, but recently burdened by a major bad debt. Industry: Rotational Moulding Outlook: Rapid growth during drought through manufacture of water tanks,
Table 2. Key issues related to technology adoption BottleTop
TechMakers
SwivelMould
The company managers view their employees as loyal, and based on a long association, almost like family. Some staff members resent the profits they believe the company owners are making and draw unfavourable comparisons to their hourly wage rate. A profit sharing scheme based upon reducing the scrap rate has been enthusiastically embraced by staff. BottleTop’s labour efficiency has increased from 76 to 92% in the last year primarily attributable to their process focus as they implement Six Sigma Manufacturing techniques
No staff-related comments or concerns appeared in interviews or observations.
SwivelMould have a high employee turnover as the work is repetitive, takes place in a hot and noisy environment and does not pay high hourly rates. SwivelMould had difficulty recruiting and retaining employees while unemployment rates were low. New employees are only given formal training after they have completed a probationary period and if they appear likely to work at SwivelMould for some time.
The Quality Manager describes product tracking as “the black hole” because once a job commences no job status information is available until the end of the manufacturing run. This issue can be addressed by the organisation as TechMakers employ a full time in-house programmer. When time permits the programmer will interface product tracking with the MRP system.
Orders are received by fax and transcribed onto job sheets by hand. As jobs are completed on the shop floor the quantity, colour etc details are confirmed by the foreman writing on the same sheet. Any variations in process are also hand written on the sheet.
TechMakers processes are well developed and highly automated and with one exception, their work in progress system, discussed in the “Tracking of Products” column. A more difficult process to address concerns the performance of the distributor that acts as the exclusive Australian agent for the US manufacturer of components used by TechMakers.
SwivelMould has not mapped its processes. The process map built for one process as part of the AmI-4-SME process was the first time the company had used process mapping. Tradition and the knowledge of gang foremen are used to guide manufacturing processes.
No comments made in relation to training.
SwivelMould has developed a competency based training program in conjunction with an external training consultant. The objectives of the training are to increase productivity, quality and produce a change in the organisational culture.
Staff
Tracking of Products Product tracking is highly automated, integrated links between moulding machines and software packages running on PCs provide a real time view of activity.
Process Improvements BottleTop is using six sigma methods to improve quality, reduce product variability and reduce waste. The company is focussing on improving each process prior to automating it. As the Operations Manager states “We want to have strong processes, we don’t want rubbish processes just being done more quickly.” When quality processes are in place BottleTop’s focus will shift to automation and then to monitoring. Training Courses A mix of in-house and external training is used at BottleTop. External training is used to provide Six Sigma training.
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Process Innovation with Ambient Intelligence (AmI) Technologies in Manufacturing SMEs
Table 2. continued BottleTop
TechMakers
SwivelMould
BottleTop managers are optimistic about their ability to grow revenue in a shrinking market. However, growing acceptance of closure systems make in countries with low labour rates may limits their growth.
TechMakers is and is the oldest and fourth largest contract electronic manufacturer (CEM) in Australia. The CEO is content to remain the fourth largest firm and claims there are advantages in not being the biggest player in the Australian market. The market for CEMs in Australia is shrinking as work moves off-shore. While the Quality Assurance Manager believes the company is committed to increasing revenue, the CEO (who is the owner of the company) stated privately that his objective is to improve the profitability of operations.
SwivelMould’s ambitious expansion plans are on track to deliver the anticipated growth in revenue. However as rain water tanks provide 5560% of annual revenue SwivelMould’s plans are dependent to some extent upon the maintenance of government rebate policies, and continuation of Australia’s ten year drought. During the course of the study the drought broke on the eastern seaboard, reducing demand for rainwater tanks. While newer entrants to the market have been unable to cope with the downturn in the tank business, SwivelMould’s Managing Director is confident of its ability to continue its expansion due to investments made in new products and its pursuit of new markets.
TechMakers are pursuing export opportunities for the technologies they have invented in house. They do not intend to attempt to compete with CEMs located overseas.
A reduction in demand for water tanks has occurred with the breaking of the drought in two cities (Sydney and Brisbane). To some extent this has been offset by increases in exports; the quantity of goods exported to the USA and China has trebled in the last year.
Highly integrated with and automated by ICT systems.
Rudimentary documentation, handwritten and physically carried between office and factory floor. Little integration with ICT systems.
Growth
Overseas Operations Sixty per cent of the company’s revenue is derived from importation and distribution activities. Logistics is important and problematic for the company as products imported as finished goods create significant supply chain challenges. BottleTop is considering employing a logistics outsourcing firm to manage these challenges Documentation & Processes Highly integrated with and automated by ICT systems.
cent of BottleTop’s product volume results from standing contracts with its top twenty customers. Beyond the top twenty customers is what the Operations Manager refers to as a “long tail” of hundreds of small customers. In contrast, TechMakers survives in a shrinking market due to its flexibility, rapid prototyping turn-around and high quality output. The CEO and Quality Assurance manager concur that “every day is different.” SwivelMould’s operations sit between the other two SMEs. SwivelMould offers a full service from product concept through design to manufacture. As each type of product requires a specialised mould, batch runs are used in production. While safety equipment is in use at TechMakers and BottleTop, SwivelMould employees resist using
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standard safety equipment such as hard hats and hearing pro