A Pseudo-Bayesian Aloha Algorithm with Mixed Priorities for Wireless ATM

In reservation MAC protocols, before obtaining a contention free access to the channel, a mobile must wait for its request packet to be successfully sent to the base station. A pseudo-Bayesian Aloha algorithm with multiple priorities is proposed in this paper to reduce the waiting time of delay sensitive request packets in a multimedia environment. Packets are transmitted in each slot according to a transmission probability based on the channel history and a priority parameter assigned to their priority class. An adaptation of the slotted protocol to the framed environment is also described. Simulation results are presented and show that the protocol offers a significant delay improvement for high priority packet with both Poisson and self-similar traffic while low priority packets only experience slight performance degradation.