A study on the optimal time synchronization accuracy in wireless sensor networks

Time synchronization may play a key role in wireless sensor networks to meet real-time and energy-saving requirements and improve data-fusion and multiplexing efficiency. In this paper, under given constraints of hardware and mathematical models, we have studied performance limitations of the time synchronization for wireless sensor networks in terms of synchronization accuracy. First, sources of synchronization errors have been identified and a mathematical model has been introduced to analyze time synchronization schemes. Second, error distributions and the accuracy limitations have been formulated according to different error-source parameters. Third, a lightweight protocol is proposed, which is capable of approaching the performance limit as well as suppressing the communication overheads. Our idea is based on the observation that there is synchronization-error correlation between nodes receiving the same sequence of time-synchronization packets. Finally the theoretical analyses have been validated by simulation results.