Traffic-load aware user association in dense unsaturated wireless networks

IEEE 802.11 based wireless local area networks (WLANs) have widespread deployment in a variety of settings in recent years. To improve the utilization of the networks, the problem of user association has been studied extensively that attempts to achieve load balance among APs. To quantify the traffic load conditions, different performance metrics have been adopted. In this paper, we focus on the unsaturated network condition. We show that the widely adopted airtime cost metric is inaccurate in predicting the channel access delay for the users under this condition. To this end, some new models are adopted to characterize the channel access delay by considering both the homogeneous and heterogeneous traffic load of different users, with which a game-theoretical based scheme is adopted for the user association problem. We compare the performance of our proposed scheme with several existing schemes under different scenarios. The results show that the proposed scheme achieve better performance in terms of traffic load balancing and fairness.