An Adaptive-Rate Time Synchronization Protocol for Wireless Sensor Networks

The time synchronization between wireless sensor network (WSN) nodes is essential for a wide range of applications requiring collaborative processing and accurate time-stamping. In this paper a new synchronization protocol for WSNs called ARSP is described and validated through simulations. The proposed protocol relies on a probabilistic, adaptive-rate approach, which in turn is based on the Simple Response Method (SRM), originally conceived for general calibration purposes. Compared to other synchronization schemes, the presented solution has three main advantages. First of all, the synchronization activities are uniformly distributed between all the WSN nodes. This is beneficial in terms of power consumption, because it prevents the battery depletion of the node servicing as a time reference. Secondly, it is very simple from the computational point of view, as it just requires the calculation of the percentage of in-tolerance nodes after each synchronization.