Distributed Medium Access Scheduling for Wireless LANs

The contention-based Distributed Coordination Function (DCF) scheme performs poorly due to collisions and idle back-off slots. Continuous efforts to improve its performance have rarely been successful because collisions and idle periods are inherent in DCF. This paper proposes a distributed medium access protocol called Distributed Medium Access Scheduling (DMAS), which enables the elimination of most collisions and idle slots in a distributed manner. The stations used for this purpose were divided into blue stations, which have the exclusive right to transmit during their turn, and red stations, which have the opportunity to transmit without overhead. The performances of DMAS, DCF, and the ideal DCF were compared through simulations. The results indicate that DMAS could be used to replace Medium Access Control (MAC) in IEEE standard 802.11 for Wireless LANs with higher throughput.