Compensated Time Synchronization in WSN with Multiple Reference Nodes

Recent technological advances such as MEMS and pervasive deployment of low-power wireless sensor devices have led to large-scaled wireless sensor networks. Time synchronization is important in largely deployed sensor nodes for various purposes including sensor data fusion and energy-efficiency. The time_sync_error is occurred to many factors. The main factor is that accumulated time error as hop count increases in multi-hop wireless sensor network. In the environment of multiple reference nodes, the reference nodes should be synchronized exactly before starting the node synchronization in the network. This paper suggests improved accuracy of the TSync algorithm in the environment of multiple reference nodes, by setting Multi time reference node (MtrN) to compensate the time differences among multiple reference nodes themselves. The simulation shows that proposed protocol reduces the accumulated time_sync_error; so improves the overall accuracy in WSN.