Lecture Notes in Computer Science 4240 Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M. Kleinberg Cornell University, Ithaca, NY, USA Friedemann Mattern ETH Zurich, Switzerland John C. Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen University of Dortmund, Germany Madhu Sudan Massachusetts Institute of Technology, MA, USA Demetri Terzopoulos University of California, Los Angeles, CA, USA Doug Tygar University of California, Berkeley, CA, USA Moshe Y. Vardi Rice University, Houston, TX, USA Gerhard Weikum Max-Planck Institute of Computer Science, Saarbruecken, Germany Sotiris E. Nikoletseas José D.P. Rolim (Eds.) Algorithmic Aspects of Wireless Sensor Networks Second International Workshop, ALGOSENSORS 2006 Venice, Italy, July 15, 2006 Revised Selected Papers 13 Volume Editors Sotiris E. Nikoletseas University of Patras and Computer Technology Institute (CTI) N. Kazantzaki Street, 26500, Rio, Patras, Greece E-mail: Preface This volume contains the papers presented at the 2nd International Workshop on Algorithmic Aspects of Wireless Sensor Networks (ALGOSENSORS 2006), held July 15, 2006, in Venice, Italy, co-located with the 33rd International Colloquium on Automata, Languages, and Programming (ICALP 2006). The ALGOSENSORS event series aims at reinforcing the foundational and algorithmic aspects of wireless sensor networks research. In particular, ALGO- SENSORS focuses on abstract models, complexity theoretic results and lower bounds, as well as the design and analysis of algorithms for wireless sensor net- works. This volume contains the 20 papers (15 regular and 5 short) that were se- lected after a rigorous review process by the Program Committee (PC) from 68 submitted papers. Each paper was reviewed by at least 2 PC members, while many papers were reviewed by 3 PC members. The broad PC was composed of 29 leading researchers worldwide, covering several aspects of this research area. Comments by the PC were provided to the authors of all submitted papers. Furthermore, this year the proceedings were prepared after the event. In this way, authors had the opportunity to revise their papers in light of the discussion at the event and then submit the final versions included in this volume. The contributed papers span several important research issues, including network topology aspects (graph models, connectivity, partitioning), deploy- ment strategies, distributed computing issues (self-stabilization, initialization), localization and tracking problems, interference minimization, security aspects, broadcasting and communication, energy management. Selected papers of ALGOSENSORS 2006 will be considered for publication in a Special Issue on Algorithmic Aspects of Wireless Sensor Networks of the Theo- retical Computer Science (TCS) Journal, edited by S. Nikoletseas and J. Rolim. Although having an international character (as also witnessed by the com- position of the PC and the geographic diversity of the submitted and accepted papers), ALGOSENSORS has a strong European perspective; in particular, we greatly appreciate the relationship with the European Association of Theoretical Computer Science (EATCS). In order to better design and coordinate the future strategy of the ALGO- SENSORS series of events, a Steering Committee was formed, composed of Josep Diaz (T.U. of Catalonia, Spain), Jan van Leeuwen (U. of Utrecht, The Nether- lands), Sotiris Nikoletseas (U. of Patras and CTI, Greece, Chair), Jos´e Rolim (U. of Geneva, Switzerland) and Paul Spirakis (U. of Patras and CTI, Greece). First, we like to warmly thank P.R. Kumar (U. of Illinois, Urbana-Champaign, USA) for delivering a very interesting Invited Talk titled “Computation, Timing and Control in Sensor Networks.” We would like to thank all the authors who submitted papers to ALGOSENSORS 2006, the members of the PC, as well VI Preface as the trusted external referees. Also we thank the members of the Organizing Committee. In particular, we thank the Publicity Chair Ioannis Chatzigiannakis for an excellent job and Athanasios Kinalis (M.Sc.) for maintaining the Web page and efficiently integrating this proceedings volume. We gratefully acknowledge the support from the Research Academic Com- puter Technology Institute (RACTI, Greece) and the TCSensor Lab of the Uni- versity of Geneva (Switzerland). We thank the Athens Information Technology (AIT, Greece) Center of Excellence for Research and Graduate Education and Intracom Defense Electronics for their support. We also thank the European Union (EU) IST/FET (“Future and Emerging Technologies”) R&D Project of the Global Computing (GC) Proactive Initiative AEOLUS (Integrated Project IST-15964, “Algorithmic Principles for Building Efficient Overlay Computers”). Finally, we wish to thank Springer’s Lecture Notes in Computer Science (LNCS) team for a very nice and efficient cooperation. October 2006 Sotiris Nikoletseas and Jos´e Rolim ALGOSENSORS 2006 PC Co-chairs Organization Program Committee Co-chairs Sotiris Nikoletseas University of Patras and CTI, Greece Jos´e Rolim University of Geneva, Switzerland Program Committee Ian Akyildiz Georgia Institute of Technology, USA Azzedine Boukerche University of Ottawa, Canada Costas Busch Rensselaer Polytechnic Institute, USA Ioannis Chatzigiannakis University of Patras and CTI, Greece Andrea Clementi University of Rome “Tor Vergata,” Italy Josep Diaz Technical University of Catalonia, Spain Tassos Dimitriou Athens Information Technology, Greece Shlomi Dolev Ben-Gurion University, Israel Deborah Estrin UCLA, USA Alfredo Ferro University of Catania, Italy Stefan Fischer University of Luebeck, Germany Pierre Fraigniaud CNRS, University Paris-Sud, France Jorge Garcia-Vidal Technical University of Catalonia, Spain Chalermek Intanagonwiwat Chulalongkorn University, Thailand Christos Kaklamanis University of Patras and CTI, Greece Miroslaw Kutylowski Wroclaw University of Technology, Poland Jan van Leeuwen University of Utrecht, The Netherlands Alberto Marchetti Spaccamela University of Rome “La Sapienza,” Italy Sotiris Nikoletseas (Co-chair) University of Patras and CTI, Greece Stephan Olariu Old Dominion University, USA Pekka Orponen Helsinki University of Technology, Finland Pino Persiano University of Salerno, Italy Jos´e Rolim (Co-chair) University of Geneva, Switzerland Christian Schindelhauer University of Freiburg, Germany Paul Spirakis University of Patras and CTI, Greece Philippas Tsigas Chalmers University, Sweden Peter Widmayer ETH Zurich, Switzerland Jiri Wiedermann Academy of Sciences, Czech Republic Manos Varvarigos University of Patras and CTI, Greece Organizing Committee Ioannis Chatzigiannakis University of Patras and CTI, Greece (Chair) Athanasios Kinalis University of Patras and CTI, Greece Giorgos Mylonas University of Patras and CTI, Greece VIII Organization Referees Beccehtti, Luca Klonowski, Marek Pasquale, Francesco Calamoneri, Tiziana Kokkinos, Panagiotis Powell, Olivier Caragiannis, Ioannis Krzywiecki, Lukasz Pulvirenti, Alfredo Crescenzi, Pilu Lauks, Anna Silvestri, Riccardo Ferro, Alfredo Leone, Pierre Vitaletti, Andrea Giugno, Rosalba Marculescu, Andrei Zag´orski, Filip Gkamas, Vassilis Moraru, Luminita Zawada, Marcin Gomulkiewicz, Marcin Moscardelli, Luca Jarry, Aubin Mylonas, Giorgos Kanellopoulos, Panagiotis Papageorgiou, Christos Kinalis, Athanasios Papaioannou, Evi Sponsoring Institutions – Research Academic Computer Technology Institute (R.A.C.T.I.), Greece. – The TCSensor Lab of the University of Geneva, Switzerland. – EU-FET R&D Project “Algorithmic Principles for Building Efficient Overlay Computers” (AEOLUS). – Intracom Defense Electronics, Greece. – Athens Information Technology (AIT), Greece. Table of Contents Regular Papers Efficient Training of Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 A.A. Bertossi, S. Olariu, and M.C. Pinotti On the Complexity of Minimizing Interference in Ad-Hoc and Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Davide Bilo` and Guido Proietti A Context Interpretation Based Wireless Sensor Network for the Emergency Preparedness Class of Applications . . . . . . . . . . . . . . . . 25 Azzedine Boukerche, Regina B. Araujo, and Fernando H.S. Silva Adaptive Initialization Algorithm for Ad Hoc Radio Networks with Carrier Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Jacek Cichon´, Miroslaw Kutylowski, and Marcin Zawada Securing Communication Trees in Sensor Networks . . . . . . . . . . . . . . . . . . . 47 Tassos D. Dimitriou Self-deployment Algorithms for Mobile Sensors on a Ring . . . . . . . . . . . . . 59 Paola Flocchini, Giuseppe Prencipe, and Nicola Santoro Minimizing Interference of a Wireless Ad-Hoc Network in a Plane . . . . . . 71 Magnu´s M. Halldo´rsson and Takeshi Tokuyama Self-stabilizing Weight-Based Clustering Algorithm for Ad Hoc Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Colette Johnen and Le Huy Nguyen Improved Stretch Factor for Bounded-Degree Planar Power Spanners of Wireless Ad-Hoc Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Iyad A. Kanj and Ljubomir Perkovi´c Wireless Communication in Random Geometric Topologies . . . . . . . . . . . . 107 Ludˇek Kuˇcera and Sˇtˇep´an Kuˇcera Localization Algorithm for Wireless Ad-Hoc Sensor Networks with Traffic Overhead Minimization by Emission Inhibition . . . . . . . . . . . 119 Pierre Leone, Luminita Moraru, Olivier Powell, and Jose Rolim The Threshold Behaviour of the Fixed Radius Random Graph Model and Applications to the Key Management Problem of Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 V. Liagkou, E. Makri, P. Spirakis, and Y.C. Stamatiou X Table of Contents Area Based Beaconless Reliable Broadcasting in Sensor Networks . . . . . . 140 Francisco Javier Ovalle-Mart´ınez, Amiya Nayak, Ivan Stojmenovi´c, Jean Carle, and David Simplot-Ryl A Flexible Algorithm for Sensor Network Partitioning and Self-partitioning Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Sandip Roy, Yan Wan, and Ali Saberi Computing Bridges, Articulations, and 2-Connected Components in Wireless Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Volker Turau Short Papers Uniquely Localizable Networks with Few Anchors . . . . . . . . . . . . . . . . . . . . 176 Zsolt Fekete and Tibor Jord´an A Locating Method for Ubiquitous Robots Based on Wireless Sensor Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Namkoo Ha, Minsu Kim, Byeongjik Lee, and Kijun Han Declarative Resource Naming for Macroprogramming Wireless Networks of Embedded Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Chalermek Intanagonwiwat, Rajesh Gupta, and Amin Vahdat Equalizing Sensor Energy and Maximising Sensor Network Lifespan Using RETT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 Khaled Matrouk and Bjorn Landfeldt On the Information Flow Required for Tracking Control in Networks of Mobile Sensing Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Sandip Roy, Liang Chen, and Ali Saberi Author Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 Efficient Training of Sensor Networks 1 2 3 A.A. Bertossi , S. Olariu , and M.C. Pinotti 1 Department of Computer Science, University of Bologna, Mura Anteo Zamboni 7, 40127 Bologna, Italy