A Multichannel MAC Protocol for Underwater Acoustic Sensor Networks

Abstract

Owing to long propagation delays and limited available bandwidth in underwater acoustics channels, it takes a long time to establish a node handshake that will decrease the channel utilization ratio. In this paper, a multi-channel time-based MAC protocol is proposed: reservation multichannel multiple accesses collision avoidance (RM-MACA) protocol. It adds channel reservation information in the RTS/CTS packet, which causes the channel reservation to finish before the last data transmission ends. The pre-reservation of the channel enhances the channel utilization ratio and the network throughput. In addition, RM-MACA also uses the control channel sensing method to estimate the channel access information of neighboring nodes; this prevents collisions with the sensing control packet. The simulation results show that the network throughput and energy consumption of RM-MACA are better than those of MACA under heavy network traffic conditions.