CS-PRMA/AP: carrier sense packet reservation multiple access with adaptive permission probability

A carrier sense packet reservation multiple access (CS-PRMA) protocol is proposed for wireless local area networks (WLAN). The proposed protocol can be viewed as a combination of CSMA with adaptive permission probability for contentions and TDMA for reserved transmissions. A mechanism for the sense of hidden transmitting terminals is described. As the original PRMA, the CS-PRMA system has the properties of soft capacity, soft handover, and distributed slot assignment and selection. The basic feature that characterises CS-PRMA with respect to the original PRMA is its very high channel efficiency. Simulation shows that a capacity of 2.50 conversations per slot is achievable for a broadband communication system with fast speech activity detectors. This capacity is close to the upper bound of the PRMA capacity, 2.78 conversations per slot. Furthermore, the consecutive contention scheme is very flexible for different traffic with different priorities, such as voice, network control signals and data messages. This protocol is suitable for broadband WLAN where a high degree of distributed system control is required.