Research And Implement Of Group Synchronization Mechanismin Wireless Sensor Network

Time synchronization is one of the most important technologies for wireless sensor network,which is a new distributed network system. At present, network time synchronization mechanisms widely used are NTP (Network Time Prototol) and GPS (Global Pisition System). However,the special natures of wireless sensor network make both of them are not suitable for application.So, it is necessary to study special time-synchronization protocol for the wireless sensor network.In recent years, multiple time-synchronization protocols designed for wireless sensor network have been proposed, the typical examples include DMTS,RBS,TPSN,FSTP and so on. But most of them still followed the synchronization ideas of the centralized network.So, there must be some synchronization error accumulation,and can not satisfy the need of synchronization accuracy in large-scale wireless sensor network.This thesis makes use of the idea of firefly synchronization in biology, introduced the idea into wireless sensor network, and proposed a group-synchronization mechanism based on M&S model. And consider the affect of the processing delay of sensor nodes and the propagation delay of the synchronization message, and we proved that for the group synchronization mechanism with delay, synchronization can not occur. So, we compensated the delay and made a simulation testing to validate our improvement is effective.At last, we make use of the GAINS-3 sensor nodes set up a time synchronization test platform, implemented our improved mechanism, and tested the synchronization accuracy, the results show that the synchronization accuracy of the improved group synchronization mechanism can achieve about 50 microsecond s.