Using Finer AIFSN Granularity to Accurately Tune the Flow Ratios in IEEE 802.11e

Abstract

The current wireless LAN (WLAN) standard, IEEE 802.11e, provides Quality of Service (QoS) differentiation by grouping the traffic into access classes (AC) with different priorities. The traffic prioritization is accomplished by using the enhanced distributed channel access (EDCA) parameters - arbitration inter-frame space (AIFS) interval, contention window (CW), and transmission opportunity (TXOP) - defined on a per-class basis, thus ensuring that each class has different probabilities of accessing the channel. The EDCA parameters are broadcasted by the access point (AP) during the beacon frames. Although, the WLAN standard IEEE 802.11e provides the means to achieve traffic differentiation, it does not specify the method to tune various EDCA parameters to achieve the desired throughput ratios across different ACs. This paper proposes a method to tune the different EDCA parameters in order to get the desired throughput ratios across different ACs that utilizes the available network bandwidth optimally.