Using the 802.11e EDCF to achieve TCP upload fairness over WLAN links

We investigate the use of the 802.11e MAC EDCF to address transport layer unfairness in WLANs. A simple solution is developed that uses the 802.11e AIFS and CW_min parameters to ensure fairness between competing TCP uploads. An analytic model of TCP transport over the modified channel is developed in order to analyse the fairness properties of the proposed scheme. In addition to fairness between competing TCP flows, consideration is extended to include characteristics of TCP flows such as RTT unfairness and responsiveness and we observe that TCP flows with a wireless bottleneck link exhibit quite different properties from flows with a wired bottleneck.