A Short Signal Backoff MAC Protocol Based on Game Theory for Underwater Sensor Networks

Underwater wireless sensor networks(UWSNs) have a long propagation delay; In order to avoid collision, the handshake mechanism is adopted in the design of media access control protocol. However, with the increase of propagation delay, The time of waiting for the feedback signal will increase continuously, resulting in the delay that too many channels are occupied by reservation. When the delay starts to be larger than the transmission time of the packet, the handshake protocol will lose its advantage in performance completely. However, the protocol that does not use the handshake mechanism has the loopholes of the confirmation mechanism or the excessive backoff after the number of nodes’s increasing, which leads to the increase of conflicts. Therefore, this paper proposes a MAC protocol based on short signal game backoff. Based on counting the number of short signal messages in the reservation stage, The protocol adopts game theory to ensure that the sending node can send without conflict after winning the reservation channel competition with the best probability without using handshake mechanism. In addition, the remaining nodes are allowed to choose the backoff time in a more reasonable way, rather than the random backoff which reduces the efficiency infinitely. The simulation results show that the protocol can greatly improve the network performance.