Wireless Sensor Networks Clock Synchronization with Selective Convergence Rate

This paper focuses on the Wireless Sensor Network (WSN) synchronization problem for event-driven measurement applications. The objective is twofold: i) to provide high accuracy in the area where an event is detected, ii) to ensure a long network life time. These two objectives are conflicting. In fact, to increase the synchronization accuracy packets must be exchanged at higher rate, thus affecting the network lifetime. In several interesting applications a trade-off can be achieved based on the observation that, if the goal is to observe a localized event, only the portion of the network surrounding the detected event requires a higher accuracy. The proposed algorithm represents a formalization of this idea. Simulations are done to show the effectiveness of the proposed algorithm.