Channel Occupancy Time BasedTCP Rate Control for IEEE 802.11 DCF

In multi-rate IEEE 802.11 wireless LAN, when multiple stations transmit frames at different data rates, the basic service set (BSS) suffers from "Performance anomaly" problem. In this paper, to solve this issue, the authors propose a TCP rate control scheme for IEEE 802.11 DCF mode. In the proposed scheme, a TCP sender controls its maximum window size based on the throughput estimated at the TCP layer. The throughput estimation is based on the number of active stations and the channel occupancy time used by each station in the BSS, which are monitored at the MAC layer. The proposed scheme forms a cross layer approach involving both MAC and TCP layers.