DSH-MAC: Medium Access Control based on Decoupled and Suppressed Handshaking for long-delay Underwater Acoustic Sensor Networks

Efficient underwater networking is still a challenging issue due to its physical limitations, like long propagation delay. In this paper, we focus on medium access control (MAC) for underwater acoustic sensor networks (UW-ASNs). Considering that the handshaking process in traditional contention-based MACs is the main hurdle for improving the network channel utilization, we propose a novel MAC protocol with Decoupled and Suppressed Handshaking (DSH-MAC) in order to reduce the time overhead, and therefore achieve more efficient channel utilization. In DSH-MAC the conventional two-way handshaking is decoupled, and hence relevant nodes are able to perform other transmissions while control packets are propagating in water. DSH-MAC also suppresses unnecessary control packets with traffic prediction, further improving the channel utilization and throughput. Our proposed protocol has been proven to be channel-efficient with both theoretical analysis and intensive simulations.