Bistable Behavior of IEEE 802.11 Distributed Coordination Function

Abstract

We show that the IEEE 802.11 distributed coordination function (DCF) wireless LAN (WLAN) exhibits bistable behavior when the total load provided to a WLAN by wireless stations is almost equal to the WLAN capacity. In one metastable equilibrium state, each station has no or only a few frames awaiting transmission in the butter and the throughput is equal to the offered load. In the other metastable equilibrium state, each station has a long queue of frames awaiting transmission and the throughput is less than the offered load. In the present study, we simulated this bistable behavior and confirmed it with an analysis based on the M/PH/1/K queueing model.