Improving throughput and user fairness through priority scheduling in WLAN

Increasing the density of access points (APs) is often required to improve the coverage and capacity of wireless local area network (WLAN). But such high density deployment may result increased interference and hence poor network performance. The channel assignment problem under this type of highly interfering environment is a challenging task. Every link may not be activated due to the limitation of number of non-overlapping channels (NOCs) and increased adjacent channel interference in case of partially overlapping channels (POCs). Existing work tries to activate as many links as possible at every slot to maximize the throughput. If we always try to activate maximum number of links in every slot, some nodes may always suffer because of their disadvantageous positions. We present a greedy algorithm which improves the average throughput of the network and minimizes the total network interference while taking care of user fairness. The proposed algorithm uses the concept of priority scheduling in which each AP is assigning some priority value to each station (STA) and we use these priority values for channel assignment and AP-STA association. We have shown that our algorithm produces better average throughput and also schedules the user traffic earlier than the algorithm based on maximizing the number of links.