Precise time synchronization based on ripple flooding in wireless sensor networks

Abstract

Precise time synchronization is inevitable for duty-cycling and TDMA in wireless sensor networks. To achieve a precise synchronized clock between nodes, fast distribution of time information of a reference node to all other nodes in multi-hop without a scheduling is necessary. In this letter, we propose a time synchronization algorithm, RFTS (Ripple Flooding Time Synchronization), that presents the fastest distribution of time information of a reference node by using synchronized packet broadcasting instead of CSMA-CA based broadcasting. We show that error in any hops is not affected by a prior hop node in the evaluation, average error and distribution time of RFTS outperforms widely used FTSP by a factor of 2.5 and 2 respectively.