Unfairness problem in WLANs due to asymmetric co-channel interference and its mitigation

Co-channel interference exists in IEEE 802.11 based wireless local area networks (WLANs) due to the limited number of non-overlapping channels in the current standards. In this paper, we investigate the impact of co-channel interference in carrier sense multiple access with collision avoidance (CSMA/CA) based WLANs via simulation. We find that the throughput unfairness among the users is severe in WLANs due to asymmetric co-channel interference among the users. We propose a centralized algorithm based on analytical analysis to configure the minimum contention window of the nodes to mitigate the throughput unfairness problem in WLANs. The performance of the proposed algorithm is evaluated by simulation and found to be very effective.