SUMMARYPrioritized parallel transmission MAC (PPTM) protocol is proposed for all-IP wireless wide area network (WAN). In this paper, we analyse its performance and compare it with modified channel load sensing protocol (MCLSP). We model PPTM as a non-preemptive priority queueing system and obtain a close form of transmission time delay for each priority class, throughput of the scheme, and number of packets in the queue in the Poisson arrival case. We find that PPTM achieves less transmission time delay than MCLSP does for high priority data. Hence, the overall performance of the system using PPTM is significantly improved. We verify the conclusions with simulation via a simplified all-IP wireless WAN.