Fair Congestion Control Mechanism Based On IEEE 802.11s Standard

Wireless Mesh Network (WMN) is a new type of broadband wireless access networks that combines the advantages of WLAN and Ad hoc Network. With the profound research on WMN and the development of its business applications, it has become an urgent problem on how to improve the network performance of WMN to meet the increasing demands. Especially, the congestion control performance of WMN is always the focus of network research, and the IEEE 802.11s standard draft has discussed the WMN congestion control scheme in detail.Based on the congestion control scheme proposed by the IEEE 802.11s standard, this thesis proposes a new fair congestion control mechanism based on price theory, with good performances on effectiveness and fairness between various traffics.In chapter one, the outline of the architecture and characteristics of WMN are provided, and the IEEE 802.11s standard and its EDCA mechanism are discussed. Then, the basic congestion control mechanism proposed in the IEEE 802.11s is introduced in chapter two. And the fairness problem and the price theory are introduced as the basic theory and provide us with a new method on congestion control strategy. In chapter three, the IEEE 802.11s congestion control scheme is implemented and simulated on the NS2 network simulator. And the performance of this scheme is briefly analyzed. Chapter four is the primary section, in which our new fair congestion control scheme is proposed, with its principles and analytic process discussed in detail. The performance of this new congestion control scheme is analyzed on NS2 network simulator in chapter five.Finally, the thesis is concluded and the future work is prospected.