A novel MAC protocol for underwater acoustic, sensor networks

Abstract

Constrained by the interior properties of underwater acoustic channels such as limited bandwidth, time-varying multipath propagation, and large propagation delay, the design of multiple access (MAC) protocols for underwater acoustic sensor networks (UWSN) poses significant challenges. Existing MAC protocols for UWSNs exhibit very low performance in channel utilization, throughput and end-to-end delay, as well as energy consumption since 1) they are based on the conventional stop-and-wait (SW) transmission scheme, and 2) fewer has error-control mechanism at the data link layer. In this paper, we assume the UWSN has a multi-hop flat topology, where there exist a sink node and some other common sensor nodes; all the nodes adopt Time Division Multiple Access (TDMA) to access channel. First, we classify all the nodes into different groups according to the numbers of hops between these nodes themselves and the sink node; the nodes belonging to different groups adopt TDMA frames with different starting time. We then propose a new MAC protocol by incorporating the multi-channel technique and the juggling-like stop-and-wait (JSW) transmission scheme (which was tailored for underwater acoustic communications), which is called the JB-MAC. Finally, simulation results are presented to highlight its good performance in terms of channel utilization, throughput and delay.