EHM: a novel efficient protocol based handshaking mechanism for underwater acoustic sensor networks

Underwater Media Access Control (MAC) protocol design faces more challenges due to the unique characteristics of acoustic communication such as the long propagation delay and limited bandwidth. The long propagation delay in underwater causes the hidden terminal and spatially unfair problem. In this paper, we propose an efficient MAC protocol for multi-hop underwater acoustic sensor networks, which we shall call the EHM—Efficient Handshaking Mechanism. It is a handshaking-based protocol that addresses the hidden terminal and spatially unfair problem, and the EHM protocol can improve the channel utilization by allowing a node to receive data packets from multiple potential senders simultaneously. This method can reduce the relative proportion of time spent on control packets. The performance of the proposed protocol is evaluated via simulations. Experiment results show that the EHM protocol outperforms in channel utilization, fairness of transmission and end-to-end packets delay.