Enhancement of MU-Sync: A Time Synchronization Protocol for Underwater Mobile Networks

In this paper, we propose a cluster-based synchronization algorithm for underwater acoustic sensor networks based on MU-Sync, called EMU-Sync. Time synchronization is an important part of many services. Although many time synchronization protocols for terrestrial wireless sensor networks have been well-developed, none of them can be applied directly in underwater wireless sensor networks. The challenges of time synchronization in underwater wireless sensor networks are long propagation delay, sensor node mobility, and energy consumption. EMU-Sync is designed to improve the performance of MU-Sync while able to maintain its low complexity. This is possible by allowing the cluster head to calculate the skew and the offset from the view of both a cluster head and a neighboring node. Simulation results confirms that EMU-Sync offers better performances than MU-Sync in both accuracy and energy efficiency. Keywords—Time Synchronization, Underwater acoustic sensor networks, Mobility, Sensor networks,