Improving throughput and fairness of transport connections in IEEE 802.11 based wireless networks

This work focuses on improving throughput and fairness of end-to-end transport connections in IEEE 802.11 based wireless networks. The IEEE 802.11 MAC provides node-level fairness in sharing wireless bandwidth but that causes uneven bandwidth distribution among uplink and downlink transmissions of transport connections, which results in their end-to-end performance degradation. This is because the access point obtains share of bandwidth as a single node although it has to manage multiple downlink transmissions. Thus, the AP is not able to send as much data downlink as it receives uplink, causing unfair bandwidth utilization by uplink and downlink transmissions. We propose a wireless bandwidth management (WBM) framework to provide fair distribution of bandwidth to transport connections, which consequently improves their throughput performance. The proposed framework utilizes the idea of TCP Trunks and sets up a Control TCP connection (a trunk or circuit) between a mobile node and the access point (AP) in order to regulate the amount of data being transferred in the uplink direction. This arrangement permits AP to control the transmission rate of TCP trunks and allocate bandwidth to uplink and downlink connections in a fair manner. Detailed analysis of the approach through simulations indicates that it achieves fair bandwidth sharing in addition to improving end-to-end throughput performance for transport connections.