Priority Based Adaptive MAC Protocol for UAV Ad Hoc Networks

In this paper, a priority based adaptive MAC protocol (PM-MAC) is proposed for UAV ad hoc networks. Firstly, in the protocol, the arriving packets are classified into different queues according to the priority of services. A Markov chain model is proposed to analyze the channel access probabilities of different queues. And it is ensured that packets with high priority can access the channel with high probability. Secondly, the size of contention window is adaptively adjusted based on backoff times and the current packet size. Finally, simulation results show that PM-MAC can guarantee the access requirements of high priority packets, and compared with the traditional backoff method, the backoff mechanism in PM-MAC achieves better performance in access success rate, channel utilization and backoff delay.