Research And Implementation Of Clock Synchronization In Wireless Sensor Networks

With the development of semiconductor chips and related technology, wireless sensor network(Wireless Sensor Network, WSN) technologies have advanced rapidly. Among these technologies, WSN clock synchronization is a fundamental one on which plenty of novel and complex applications will be. Meanwhile the performance of those may much depend on the quality of clock synchronization. However, WSN clock synchronization is distinct from that in traditional computer network. Therefore, the research of the WSN synchronization clock is a very meaningful task.The main work of this thesis is as follows:The model of WSN clock synchronization was established and the main challenges in WSN are introduced. After that, the basic principles of three clock synchronization protocols/algorithms(FTSP, GTSP and PulseSync) are explained and analyzed. This thesis point out the clock granularity effects on clock synchronization(especially after a "multi hop"). To the issue, an improved PulseSync clock synchronization algorithm which can reduce the clock granularity without increase the operating frequency of nodes was proposed. All of these clock synchronization protocols and algorithms are implemented on Contiki OSThe simulation results are analyzed and compared briefly and those showed that the improved PulseSync performed better than the original one.