Abstract
We study the time synchronization problem for large-scale wireless sensor networks in the high-density regime. Our interest in this problem arises from a sensor networking application, where a large number of power-constrained radio transmitters coordinate their access to a Gaussian multiple access channel to cooperate in generating a waveform stronger than any individual node would be able to generate. In a companion paper to this one, we study theoretical aspects of a time synchronization mechanism that is optimal in the limit of asymptotically high network densities. In this work we summarize those results, and explore practical implementation issues of that mechanism in the context of networks with large, but finite, numbers of nodes. Through simulations, we find that the synchronization mechanism performs very well for finite (and relatively small) networks, maintaining tight clock synchronization indefinitely.
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Work supported by the National Science Foundation, under awards CCR- 0238271 (CAREER), CCR-0330059, and ANR-0325556.
An-swol Hu was born in Mt. Kisco, New York on February 24, 1980. He received his B.S. in Electrical Engineering from Stanford University in 2002. Currently he is a Ph.D. candidate in the School of Electrical and Computer Engineering at Cornell University. His research interests include information theory and statistical signal processing, with applications to sensor networks.
Sergio D. Servetto was born in Argentina, on January 18, 1968. He received a Licenciatura en Informática from Universidad Nacional de La Plata (UNLP, Argentina) in 1992, and the M.Sc. degree in Electrical Engineering and the Ph.D. degree in Computer Science from the University of Illinois at Urbana-Champaign (UIUC), in 1996 and 1999. From 1991 to 1994 he worked as a programmer for IBM Argentina. From 1994 to 1999 he was a Graduate Research Assistant at UIUC. From 1999 to 2001 he worked at the Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland. Since Fall 2001, he has been an Assistant Professor in the School of Electrical and Computer Engineering, Cornell University. He is also a member of the field of Applied Mathematics at Cornell. His research interests are centered around information theoretic aspects of networked systems, with a current emphasis on problems that arise in the context of large-scale sensor networks.
Sergio was the recipient of the 1998 Ray Ozzie Fellowship, given to “outstanding graduate students in Computer Science”, and of the 1999 David J. Kuck Outstanding Thesis Award, for the best doctoral dissertation of the year, both from the Dept. of Computer Science at UIUC. He is also the recipient of a 2003 NSF CAREER Award. He has served on the technical program committee of various conferences (IEEE Infocom, Globecom, ICC, SECON; ACM MobiCom, MobiHoc, SenSys, WSNA). He will present a tutorial at ACM MobiHoc 2004, on the topic of “Efficient Architectures for Information Transport in Wireless Sensor Networks”. He is currently writing a book, tentatively entitled “Digital Communications over Packet-Switched Networks”, to be published by Kluwer.
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Hu, As., Servetto, S.D. Algorithmic Aspects of the Time Synchronization Problem in Large-Scale Sensor Networks. Mobile Netw Appl 10, 491–503 (2005). https://doi.org/10.1007/s11036-005-1561-1
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DOI: https://doi.org/10.1007/s11036-005-1561-1