Reliable time synchronization protocol in sensor networks considering topology changes

In this paper, we propose a reliable time synchronization protocol (RTSP) in sensor networks considering topology changes. Due to movement of sensor nodes, running out of energy or crashes in the network, the topology of sensor networks changes very frequently. In the proposed method, synchronization error is decreased by creating a hierarchical tree with lower depth and reliability is improved by maintaining and updating the information of candidate parent nodes. The RTSP reduces recovery time and cost compared to the TPSN (Timing-sync Protocol for Sensor Networks) when there are changes in topology. Simulation results show that RTSP has about 10% better performance than TPSN in synchronization accuracy. The number of messages in RTSP is 10%-30% lower than that in TPSN when there are topology changes.