TCP ACK Congestion Control and Filtering for Fairness Provision in the Uplink of IEEE 802.11 Infrastructure Basic Service Set

Most of the deployed IEEE 802.11 wireless local area networks (WLANs) use infrastructure basic service set (BSS) in which an access point (AP) serves as a gateway between wired and wireless domains. We present the transport layer uplink unfairness problem that occurs due to uneven bandwidth sharing between upstream transmission control protocol (TCP) data and downstream TCP acknowledgment (ACK) packets. We propose ACK congestion control and filtering in the WLAN downlink to improve fairness between uplink flows. Through extensive simulations, we show that the proposed heuristic algorithms not only enhance both short- and long-term fairness but also increase channel utilization in the 802.11 WLAN. Another attractive feature for the proposed algorithms is the independence of the performance from variable TCP round trip times (RTTs).