Quality of Service in 802.11 Networks: Performance Analysis of the 802.11 Distributed Coordination Function

Abstract

The dissertation presents the results of studies , analysis, design and simulations of distribute coordination function performed in the course of the project. As the IEEE 802.11 based internet access is becoming ubiquitous available with simulations we evaluate the MAC protocol modes distribution coordination function (DCF), enhanced DCF (EDCF) and contention free bursting (CFB).We have verified our simulation model by cross-checking it with the results of other researchers. under the assumption of a finite number of stations and ideal channel conditions in a single-hop WLAN. Despite its appealing simplicity, our unified model and analysis are validated very well by simulation results. Ultimately, by means of the proposed model, we are able to precisely evaluate the differentiation effects of EDCF parameters on WLAN performance in very broad settings, a feature which is essential for network design. In addition to designs of wireless nodes by using ns-2 simulators and this simulator used simulations results describe in this reports. We present quantitative results of the perceptual quality and enhance the precision of performance evaluation. Furthermore, I verified my EDCF extension with the IEEE 802.11e simulation model of Mangold et al. [2]. Mangold used a WARP simulator which differs fundamentally from ns-2. However, both simulation models yield similar results for the same simulation scenarios.