Enhancing TCP Fairness in Wireless Networks using Dual Queue Approach with Optimal Queue Selection

Abstract

Fairness is one of the important issues when Transmission Control Protocol is used in an asymmetric wireless network. The throughput of uplink or downlink flow abruptly degrades when there is a simultaneous uplink and downlink TCP flow. The per-flow queuing set up to improve the TCP fairness is very difficult to manage for all the uplink and downlink flows and the scalability is degraded. To resolve such constraints, a novel and pragmatic dual queue approach combined with Optimal Queue Selection, TCP-Optimal Queue Selection, is proposed. The two different queues, one for the TCP data packet and the other for the Acknowledgement packet are used. The optimal queue is selected based on the priority or probability, to achieve fairness. The optimal queue size and the queuing delay of the Acknowledgement queue for probability based scheduling are derived and the behavior of dual queue scheme is analyzed. The proposed work is also evaluated using simulation and the results obtained show that dual queue schemes are effective in mitigating the unfairness issue of TCP.