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  • Research Article
  • Open Access

Clock Estimation for Long-Term Synchronization in Wireless Sensor Networks with Exponential Delays

EURASIP Journal on Advances in Signal Processing20072008:219458

  • Received: 25 June 2007
  • Accepted: 4 October 2007
  • Published:


Although the existing time synchronization protocols in wireless sensor networks (WSNs) are efficient for short periods, many applications require long-term synchronization among the nodes, for example, coordinated sleep and wakeup modes, and synchronized sampling. In such applications, experiments have shown that even clock skew correction cannot maintain long-term clock synchronization and a quadratic model of clock variations can better capture the dynamics of the actual clock model involved, hence increasing the resynchronization period and conserving significant energy. This paper derives the maximum likelihood (ML) estimator for all the clock parameters in a two-way timing exchange model with exponential delays. The same estimation procedure can be applied to one-way timing exchange models with little modification.


  • Wireless Sensor Network
  • Quantum Information
  • Quadratic Model
  • Significant Energy
  • Full Article

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Authors’ Affiliations

Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843-3128, USA


© Q. M. Chaudhari and E. Serpedin. 2008

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.