Providing absolute priority and airtime fairness in WLANs

Although IEEE 802.11e Enhanced Distributed Channel Access (EDCA) provides service differentiation, it leaves much to be desired in terms of aggregate throughput and quality of Service (QoS) differentiation among priority classes. Furthermore, EDCA does not provide airtime fairness for nodes with different transmission rates. Therefore, the throughput of a node transmitting at a high transmission rate is heavily degraded when some nodes transmit at a low transmission rate, which is known as performance anomaly. In this paper, we propose a new medium access scheme, AS-MAC, which provides excellent absolute priority service, the successful transmission time (ST-time) fairness and optimal throughput performance in 802.11 WLANs.