Distributed association control considering user utility and user guidance in IEEE802.11 networks

Public WLANs based on IEEE802.11 standard are now widely deployed. In an environment offering several APs (Access Points), a UTE (User Terminal Equipment) needs to choose which AP to associate with. Conventionally, the UTE associates with the AP with the strongest RSSI (Received Signal Strength Indicator). This simple approach, however, can degrade the efficiency of network utilization since the UTE is likely choose a heavily loaded AP, even though choosing a more lightly loaded AP would be more effective. So far, some AP association schemes have been proposed. To the best of our knowledge, however, these existing schemes do not take into account of individual difference among UTEs in terms of user utility, physical data rate, traffic characteristics such as traffic demand and frame length. In this paper, we propose a distributed user association control scheme that does considering such UTE characteristics. The proposed scheme needs to estimate uplink and downlink throughput, so that we introduce a throughput estimation method that considers UTE diversities. Through numerical simulations, we confirm that our distributed control scheme can improve user utility and fairness.