An ECN-Based Congestion Control Algorithm for TCP Enhancement in WLAN

In wireless LAN connected with Internet, the anomaly of wireless channel and the greedy nature of closed loop control in TCP lead to the congestion problem and significant unfair bandwidth distribution between TCP flows. In this paper, an ECN-based access point congestion control algorithm called APCC (AP congestion control) is proposed. The main properties of APCC are: (1) Using both wireless channel load and buffer queue length as congestion indicators, APC Censures low packet loss rate, low queue delay, and high goodput; (2) APCC guarantees the up/down TCP fairness by marking the ECN bit in TCP DATA and ACK packets; (3) Taking into account the wireless channel rate of each TCP flow, APCC sets different ECN marking probability for each flow to achieve the time fairness and high network efficiency.