Downlink and uplink resource allocation in IEEE 802.11 wireless LANs

Wireless local area networks (WLANs) based on the IEEE 802.11 standard are becoming increasingly popular and widely deployed. It is likely that WLAN will become an important complementary technology for future cellular systems and will typically be used to provide hotspot coverage. In this paper, the complementary use of WLANs in conjunction with mobile cellular networks is studied. We identify the fairness problem between uplink and downlink traffic flows in the IEEE 802.11 distributed coordination function and then propose an easy solution that can be implemented at the access point (AP) in the MAC layer without modification of the standard for stations (STAs). This solution aims at providing a controllable resource-allocation method between uplink and downlink traffic flows and adapting the parameters according to the dynamic traffic load changes. The proposed solution also enhances the system utilization by reducing the probability of frame collision.