Comparative analysis of time synchronization schemes for wireless sensor networks

Time synchronization is one of the major concerns in wireless sensor networks. As the sensor nodes have limited energy resources and once deployed may remain unattended for a long period of time, so for the entire network to work in coordination it is important to maintain synchronization between all the nodes in the network. In this paper we compare two existing time synchronization schemes namely Reference Broadcast Synchronization and Adaptive Clock Synchronization for different network environments and present an algorithm which provides network wide synchronization while assuring the minimal energy dissipation. In a sensor network every time a synchronizing node in a region dies, all the receiver nodes under its vicinity are dropped which affects the network coverage and connectivity of that region in an adverse manner. Thus re-synchronization of the entire network is necessary, which is an inefficient procedure for large networks as it consumes a lot of energy. The proposed algorithm instead of re-synchronizing the entire network again only synchronizes the particular region which is associated with the depleted synchronizing node.