A channel-aware depth-adaptive routing protocol for underwater acoustic sensor networks

In underwater acoustic networks, a transmission is done by means of acoustic wave. However, acoustic transmissions suffer long propagation delay and high bit error rate, especially for real time applications. Since speed of sound and underwater noises are varied with water depth, therefore, this paper takes sound speed and underwater noises into account and proposes a channel-aware depth-adaptive routing protocol, named CDRP, for underwater acoustic sensor networks to relief propagation delay and transmission error rate. In CDRP, the source constructs a virtual ideal path to the sink while it has data to send. According to its one-hop neighbor information, the source then chooses one or several proper forwarders to relay the data. Likewise, the forwarders select next forwarders in the same way until the data is sent to the sink. To our best knowledge, CDRP is the first routing protocol considering the effects of underwater noise and sound speed with depth variation. The simulation results show that CDRP has better performance in end-to-end delay and packet delivery ratio.