Investigation And Performance Analysis Of Cross-Layer Design In Wireless Mesh Networks

With the increasing amount of resources and applications of Internet, the needs for easily access to the high speed Internet are raised out no matter whenever or wherever we are. Under such a background of demand, the wireless Internet is emerging. The wireless Internet in future would be a wireless data network, a compromise of all kinds of heterogeneous networks, with a much larger scale and complexity. It is the wireless extension of current Internet in a broad sense, which brings great challenges to the design of wireless Internet protocol stack. It is also a hot topic in the B3G/4G research.The Wireless Mesh Network (WMN) is considered to be "The Wireless Version of Internet". The distinctive merits of WMN make it a potential technology to construct the B3G/4G world. What's more, it is the only feasible way so far to build the commercial mobile Ad hoc network. But, due to the characteristics of WMN in terms of topology, transmission link and traffic, the conventional layered protocol design methods for wired networks can not guarantee the OoS performance for WMN. To reach a tradeoff between the efficiency of radio resources and QoS requirements to multimedia traffic, it is required to explore new method, cross-layer design, for WMN based on physical layer, MAC layer, routing layer, etc. The main task of this thesis is to design the WMN cross-layer scenario, analyze it with the results of simulation and make some significant conclusions.In chapter one, the basis of WMN, necessity of the cross-layer design, the structure and contribution of this thesis are outlined. Then, the basic demand on cross-layer design, general principles and methods, key technologies to be deeply researched are summarized in chapter two. Some current MAC and routing cross-layer design schemes are introduced in third part of the thesis. A new routing proposal which is based on SNR, adaptive modulation and power control is proposed, another MAC improved scheme based on IEEE 802.11e is also discussed. In chapter 4, being aware of link loss through cross-layerinterconnection and suitable for WMN, an improved scheme based on DSR is proposed, simulated and analyzed.Finannly, the thesis is concluded and the future work is prospected.