Network-wide clock synchronization via message passing with exponentially distributed link delays

Davide Zennaro, Aitzaz Ahmad, Lorenzo Vangelista, Erchin Serpedin, Hazem Nounou, Mohamed Nounou

Research output: Contribution to journalArticle

18 Citations (Scopus)


Clock synchronization has become an indispensable requirement in wireless sensor networks due to its central importance in vital network operations such as data fusion and duty cycling, and has attracted considerable research interest recently. Assuming exponentially distributed random delays in a two-way message exchange mechanism, this work proposes a network-wide clock synchronization algorithm using a factor graph representation of the network. Message passing using the max-product algorithm is adopted to derive the update rules for the proposed iterative procedure. A closed form solution is obtained for each node's belief about its clock offset at each iteration. Simulation results show that the application of the proposed message passing-based network-wide clock synchronization algorithm provides convergent estimates for both regular cycle-free and random topologies. Moreover, the mean square error (MSE) performance of the proposed algorithm is also compared with the Cramer-Rao bound (CRB) for small example networks, which further highlights the effectiveness of the proposed algorithm.

Original languageEnglish
Article number6468998
Pages (from-to)2012-2024
Number of pages13
JournalIEEE Transactions on Communications
Issue number5
Publication statusPublished - 28 Feb 2013



  • Clock synchronization
  • factor graphs
  • max-product algorithm
  • message passing
  • wireless sensor networks

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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