Effect of service differentiation on QoS in IEEE 802.11e enhanced distributed channel access: a simulation approach

Godwin Onyekachi Ugwu,Udora Nwabuoku Nwawelu,Mamilus Aginwa Ahaneku,Cosmas Ikechukwu Ani

doi:10.1186/s44147-021-00055-3

Godwin Onyekachi Ugwu, Udora Nwabuoku Nwawelu + Show 2 more

Open Access

https://doi.org/10.1186/s44147-021-00055-3

Copy DOI

Abstract

The enhanced distributed channel access (EDCA) protocol is a supplement to IEEE 802.11 medium access control (MAC), ratified by IEEE 802.11e task group to support quality of service (QoS) requirements of both data and real-time applications. Previous research show that it supports priority scheme for multimedia traffic but strict QoS is not guaranteed. This can be attributed to inappropriate tuning of the medium access parameters. Thus, an in-depth analysis of the EDCA protocol and ways of tuning medium access parameters to improve QoS requirements for multimedia traffic is presented in this work. An EDCA model was developed and simulated using MATLAB to assess the effect of differentiating contention window (CW) and arbitration inter-frame space (AIFS) of different traffic on QoS parameters. The optimal performance, delay, and maximum sustainable throughput for each traffic type were computed under saturation load. Insight shows that traffic with higher priority values acquired most of the available channels and starved traffic with lower priority values. The AIFS has more influence on the QoS of EDCA protocol. It was also observed that small CW values generate higher packet drops and collision rate probability. Thus, EDCA protocol provides mechanism for service differentiation which strongly depends on channel access parameters: CW sizes and AIFS.

Highlights

Institute of Electrical and Electronic Engineers (IEEE) 802.11 known as wireless local area network is considered the most accepted and deployed wireless communication standards
This work is based on the activities that take place at the wireless local area network (WLAN) work stations (WSTA) and access point (AP); the model is based on WLAN AP which operates on carrier sense multiple access with collision avoidance (CSMA/CA) principles
AC1 (BE) and AC3 (VO) only were modeled using default enhanced distributed channel access (EDCA) access parameters. They were configured with the same arbitration inter-frame space (AIFS) value but different contention window (CW) size and vice versa to analyze the impact of AIFS number and CW size on quality of service (QoS) parameters

Summary

Introduction

IEEE 802.11 known as wireless local area network is considered the most accepted and deployed wireless communication standards. Some of the popular WLAN access control protocols are distributed coordination function (DCF), enhanced distributed channel access (EDCA), and hybrid. The DCF does not guarantee QoS requirements for real-time services. This is because all the traffic is allowed to go through the same queueing and transmission processes. The EDCA protocol cannot guarantee strict QoS to real-time applications. Whereas by using appropriate scheduler, the HCCA protocol can provide soft QoS guarantee to real-time applications [8]

Methods

Results

Conclusion