Open Access Research

Achieving per-flow and weighted fairness for uplink and downlink in IEEE 802.11 WLANs

Chiapin Wang

Author Affiliations

Department of Applied Electronic Technology, National Taiwan Normal University, Taipei, Taiwan

EURASIP Journal on Wireless Communications and Networking 2012, 2012:239 doi:10.1186/1687-1499-2012-239

Published: 31 July 2012

Abstract

In this article, we investigate a fairness issue between uplink and downlink flows in IEEE 802.11 Wireless Local Area Networks (WLANs). We propose a cross-layer adaptive algorithm which dynamically adjusts the minimum contention window size of access point according to the amount of downlink users and channel conditions to achieve per-flow fairness. In case that uplink and downlink transmissions are with different bandwidth demands for various applications, our algorithm can efficiently find the optimal minimum contention window size which provides weighted fairness based on their resource requirements. The simulation results demonstrate that our scheme can effectively provide both per-flow fairness and weighted fairness in a varying WLAN environment.

Keywords:
Fairness; IEEE 802.11 WLAN; MAC contention control; Bandwidth allocation