A TDMA MAC protocol for underwater acoustic sensor networks

The hostile seawater channel condition poses research challenges of designing reliable and efficient communication protocols for underwater acoustic sensor networks. Especially, long propagation delay of acoustic waves in water makes networks poor performance. Due to low channel utilization of traditional TDMA protocol, in this paper, we present a new medium access control (MAC) protocol called I-TDMA, which interleaves data packets in empty time axis by taking advantage of long propagation delay in underwater channel. The proposed scheme improves channel utilization, and simulation tests on OPNET radio modeler show that I-TDMA has much higher throughput and lower delay than traditional TDMA protocol.