ELOTS: Energy-efficient local optimization time synchronization algorithm for WirelessHART networks

The traditional Reference Broadcast Synchronization (RBS) algorithm and its efficient version ERBS algorithm have a problem that the network overhead is very high as the number of nodes in WirelessHART networks increases. In this paper, an energy-efficient local optimization time synchronization algorithm is proposed. This algorithm at first computes the mean time offset for neighbor nodes receiving multiple reference messages, estimates the time offset by the maximum a posteriori estimation and finally adjusts the local clock according to the estimation. The simulation results indicate that, the time synchronization precision of this time synchronization algorithm is about 196% higher than that of RBS and 25% higher than ERBS; also, its network overhead and energy consumption are greatly reduced.