Abstract: A new multiple access control(MAC) protocol-the user adaptive scheduling multiple access(UASMA) protocol is proposed, which can perfectly schedule the packet transmission according to the exact number of active mobile terminals(MTs) determined by the self-organizing algorithm, and can adjust the number of packets sent by one node in one frame properly. The UASMA protocol employs a unique frame structure and presents the concepts of reference-frame-length, thus increasing the utilization ratio of the channel greatly. Meanwhile, the UASMA protocol proposes an efficient collision resolution algorithm for guaranteeing that active MTs can access the channel rapidly. Finally, the performance of the UASMA protocol is evaluated by simulation and compared with CSMA, rouding-poll and UPMA protocols, with the simulation results showing that the former has better performance than the latter.

Key words: MAC protocol, rounding-poll, user number, packet overstock