A Priority-based Parallel Schedule Polling MAC for Wireless Sensor Networks

—MAC (medium access control) protocol plays an important role in Wireless Sensor Networks (WSNs) due to limited bandwidth and battery. MAC protocol that provides Priority-based quality of service (QoS) which satisfies various traffic transmission requirement will form the base of highperformance network application. This paper presents a new priority-based parallel schedule polling MAC protocol (PPSPMAC) in WSNs, which combines polling orders with access policies including Gated and Exhaustive access policies to realize the priority-based scheme and reduces the overhead time through parallel schedule. Then the PPSP-MAC model is set up by method of imbedded Markov chain theory and generation function and the key system performance characteristics such as mean queue length, cycle time and throughput are explicitly analyzed. Theoretical and simulation results are identical and show that the new protocol achieves a better performance than the existing protocols such as IEEE802.11, IEEE802.15.4, SMAC, PQ-MAC, etc.