Study of the TCP upstream/downstream unfairness issue with per-flow queuing over infrastructure-mode WLANs

Abstract

Fairness is an important issue in WLANs due to their shared media nature. Essentially, IEEE 802.11 MAC protocols have been designed to provide fair access for all the competing mobile hosts. However, the fairness at MAC layer cannot be maintained at TCP layer in the presence of both mobile senders and receivers accessing to wired networks. In this paper, we investigate the TCP upstream/downstream unfairness issue over WLANs with per-flow queuing employed at the access point (AP). The interactions between the IEEE 802.11 MAC protocol and TCP are evaluated through analysis and simulation. Based on the derived analytical model, an efficient solution is proposed to be implemented at the AP for fairness achievement. Copyright © 2005 John Wiley & Sons, Ltd.