Research On Time Synchronization Algorithm In Wireless Sensor Networks

Wireless sensor network(WSN),as a distributed multidisciplinary network,needs a variety of technologies to support its operation.As one of the core technologies of wireless sensor networks,time synchronization plays an important role in the whole network operation.At present,clock synchronization technology has become one of the hotspots in wireless sensor networks.At the same time,with the application of wireless sensor network more and more widely,the traditional time synchronization algorithm has been unable to meet all the application needs.Therefore,it is very urgent and necessary to study the time synchronization technology deeply.Aiming at the problem of insufficient synchronization precision in the receiver synchronization algorithm and the poor adaptability of multi hop network,an improved algorithm is proposed based on the receiver synchronization algorithm.The improved algorithm is divided into two stages,in the preparation stage,to improve the network adaptability and robustness by constructing a multi hop network model;in the synchronization phase,to improve the precision of time estimation method of time deviation by least squares method.At the same time,the improved algorithm inherits the advantages of the original algorithm.The theoretical analysis and simulation results show that the proposed algorithm improves the accumulative error in the 20 hop network model by a factor of about 48 microseconds,which is improved by a factor of about 28 microseconds compared with the original algorithm.In the case of time correlation,the mean square error is 0.1 when the timestamp is exchanged for 40 times,compared with the original algorithm by a factor of less than 0.45.When the time is not related,the mean square error is 0.1 when the timestamp is exchanged for 40 times,which is less than that of the original algorithm by a factor of 0.2.In the multi hop network of 100 nodes,the synchronization period of IROS algorithm is about 11.1 seconds,which is reduced by about 9.8 seconds.In the same network with 100 nodes,the message overhead is the same as the original algorithm.