The Capacity of the Asynchronous Compound Multiple Access Channel and Results for Random Access Systems

The capacity region of an asynchronous system with two sources and two receivers is analyzed. The capacity region is first derived for a general discrete memoryless channel. The result is then applied to a random access system in which sources may either transmit information-bearing symbols or idle (empty) symbols in each time slot. The capacity region for this random access system is compared to the corresponding queueing stability region and it is demonstrated that the two regions do not coincide. This comparison is the primary contribution of our work; our result is a deviation from all previous results on the relation between information-theoretic capacity and queueing stability for random access systems