title: Study of consensus-based time synchronization in wireless sensor networks.
abstract: Recently, various consensus-based protocols have been developed for time synchronization in wireless sensor networks. However, due to the uncertainties lying in both the hardware fabrication and network communication processes, it is not clear how most of the protocols will perform in real implementations. In order to reduce such gap, this paper investigates whether and how the typical consensus-based time synchronization protocols can tolerate the uncertainties in practical sensor networks through extensive testbed experiments. For two typical protocols, i.e., Average Time Synchronization (ATS) and Maximum Time Synchronization (MTS), we first analyze how the time synchronization accuracy will be affected by various uncertainties in the system. Then, we implement both protocols on our sensor network testbed consisted of Micaz nodes, and investigate the time synchronization performance and robustness under various network settings. Noticing that the synchronized clocks under MTS may be slightly faster than the desirable clock, by adopting both maximum consensus and minimum consensus, we propose a modified protocol, MMTS, which is able to drive the synchronized clocks closer to the desirable clock while maintaining the convergence rate and synchronization accuracy of MTS.
authors.affiliation: State Key Laboratory of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Zheda Road 38#, Hangzhou 310027, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Zheda Road 38#, Hangzhou 310027, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Zheda Road 38#, Hangzhou 310027, China.
authors.forename: Jiming
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Zheda Road 38#, Hangzhou 310027, China. Electronic address: pcheng@iipc.zju.edu.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
keywords: Consensus-based time synchronization; Experimental study; Maximum and minimum consensus; Wireless sensor networks