A control-theoretic approach to improving fairness in DCF based WLANs

Achieving fair bandwidth distribution among uplink and downlink flows in the infrastructure based wireless local area networks (WLAN) which the distributed coordination function (DCF) mode is difficult. In this paper we present a new control theoretic approach to achieve a fair bandwidth distribution among the flows regardless of the transport protocol used by the flows. In addition, we explore methods to improve the channel bandwidth utilization and reduce the delay while improving the fair distribution. Our approach combines an AQM scheme for IFQ queue and the MAC layer design to achieve this goal. The effectiveness of our approach is demonstrated through extensive simulations over a wide range of network scenarios.