Achieving Fair TCP Access in the IEEE 802.11 Infrastructure Basic Service Set

We illustrate the transport layer unfairness problem in the IEEE 802.11 Wireless Local Area Networks (WLANs). We design a link layer access control block for the Access Point (AP) in order to provide fair Transmission Control Protocol (TCP) access in an 802.11 infrastructure Basic Service Set (BSS). The novel and simple idea of the proposed control block is employing a congestion control and filtering algorithm on TCP Acknowledgment (ACK) packets of uplink flows, thereby prioritizing the access of TCP data packets of downlink flows at the AP. We quantify the parameters of the proposed ACK congestion control and filtering algorithm based on the measured average downlink TCP data access rate. Via simulations, we show that the introduction of the proposed link layer access control block to the protocol stack enhances short- and long-term fairness in a wide range of scenarios.