QoS-aware MAC protocol based on wireless multimedia sensor networks for underground coal mines

The send frequency,bandwidth,delay and direction of sensing data,voice and video in underground coal mines as well as the quality assurance requirements of network service have been summarized. A QoS-aware MAC pro- tocol based on wireless multimedia sensor networks for underground coal mines was proposed. The different services can be implemented for sensing data,voice and video by designing different contention windows,which guarantees the QoS requirements of three kinds of services. Markov chain models of backoff series and backoff time counters for three kinds of services were established,and the performance of QoS-aware MAC protocol for saturation throughput and MAC layer access latency were analyzed. Simulations were carried out in both low load and high load conditions with the proposed QoS-aware MAC protocol. It is showed that the throughput of sensing data and voice can be increased by re- ducing the throughput of video services,and the delay of sensing data and voice can be reduced by increasing the de- lay of video services.