In this paper, we present an access scheme to satisfy the QoS requirements for two classes of traffic during the contention phase of packet-switched wireless communications. In the proposed scheme, different classes of users contend with other users for resources based on controlled class-dependent permission probabilities. We prove that our algorithm is stable for a large class of arrival processes. Under certain QoS requirements, we derive an upper-bound on the throughput for a general class of random access algorithms. We show that the throughput of our algorithm asymptotically approaches this upper-bound. We also show, through numerical examples, that our algorithm achieves high network utilization.
Xin Liu, Edwin K. P. Chong, Ness B. Shroff