A Robust Single Hop Tree Structured Time Synchronization Protocol for Wireless Ad-Hoc Sensor Networks

Wireless ad-hoc sensor networks are deployed in order to observe some real world phenomenon with the intent to improve the daily life of common man, boost industrial processes, facilitate environment protection and enhance law enforcement. Time synchronization is critical for these networks so that the nodes in the network can accurately report event timestamps and fine-tune their coordinated distributed activities. Time synchronization algorithms proposed in the past have considered various critical issues related to nodes such as computing, resources involved in storage and communication, energy efficiency of the algorithm etc. Changing network dynamics still remains a challenge to be addressed by time synchronization algorithms as the nodes are deployed randomly either at the time of network establishment or at a later stage when the network is established and may die or disconnect in the same fashion. In this paper an energy efficient and robust protocol to support network dynamics in time synchronization protocol is presented. The protocol incorporates a mechanism which ensures that synchronization of the nodes in the network remains unaffected even if any of the nodes involved in synchronization process gets disconnected. The number of messages involved in the synchronization process in the suggested protocol is also reduced as compared to earlier protocols that makes the suggested one more energy efficient.