Distributed time synchronization under bounded noise in wireless sensor networks

Jianping He, Xiaoming Duan, Peng Cheng, Ling Shi, Lin Cai

Abstract: It is important and challenging to achieve accurate time synchronization in wireless sensor networks. Various noises, e.g., communication delay, clock fluctuation and measurement errors, are inevitable and hard to be estimated accurately, which is the main challenge for achieving an accurate time synchronization. In this paper, we focus on how to achieve accurate time synchronization by considering a practical noise model, bounded noise, which may not satisfy any known distributions. The principle that a bounded monotonic sequence must possess a limit and the concept of maximum consensus are exploited to design a novel time synchronization algorithm for the network to achieve accurate synchronization under bounded noise. The proposed algorithm is fully distributed, with high synchronization accuracy and fast convergence speed, and is able to compensate both clock skew and offset simultaneously. Moreover, we prove that the algorithm converges with probability one, which means that time synchronization is achieved completely, and the probability of the complete synchronization converges exponentially.