Adaptive Access Mechanism Based on Network State Detection in Multi-rate IEEE802.11 WLANs

This paper addresses the problem of channel access in multi-rates IEEE802.11 WLANs (Wireless Local Area Networks). Unlike some current solutions for performance anomaly only aiming to the saturated network, we propose a fine-grain channel access mechanism that takes the saturated and unsaturated network into account simultaneously. Meanwhile, we present a model to detect the network state under different network density. This novel framework can detect the network state by collision rate for the dynamic network scenarios and perform more efficient channel access by combining the legacy IEEE802.11 DCF (Distributed Coordination Function) and airtime fairness algorithm. The simulations show that our algorithm can improve the aggregate throughput and reduce the collision rate during channel access compared to the legacy DCF mechanism.