【作者】 马忠建；

【导师】 方旭明；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2006， 硕士

【摘要】 随着因特网资源的不断丰富,以及因特网应用的进一步广泛,人们希望不论何时、何地都能够高速、准确地接入因特网,无线因特网的需求便应运而生。未来的无线因特网将是各种异构网络融合的无线数据网,在网络规模和复杂性上都将远远超过现在的因特网。从广义上讲,它是现有因特网的无线延伸。这将给无线因特网协议栈的设计带来巨大的挑战,同时也是B3G/4G的热点研究课题之一。 无线Mesh网络(Wireless Mesh Network,WMN,无线网状网或无线网格网)被称为“因特网的无线版本”,它具有一些独特的优点,成为构建B3G/4G的潜在技术之一,也是迄今为止唯一一种建设商用移动Ad hoc网络的可行技术。但是,由于WMN在拓扑、传输和业务上的特性,传统的用于有线网络的分层协议设计方法已不能保证其服务质量(Quality of Service,QoS)。探索基于物理层、MAC层、路由等协议层的WMN跨层设计方法的目标是在无线资源利用率和多媒体业务的QoS需求两方面达到较好的折衷。本文的主要工作就是对WMN的跨层设计方法和方案进行研究、设计和仿真分析。 论文的第一章介绍了WMN的基本情况、跨层设计的必要性、论文的组织结构以及主要的工作。论文的第二章探讨了WMN跨层设计的基本要求、一般原则和方法,并归纳了目前WMN跨层设计中亟待深入研究的一些理论和关键技术。第三章介绍了现有的几种MAC、路由协议跨层设计方案,并分别提出了一种基于信噪比(Signal to Noise Ratio,SNR)、自适应调制和自适应功率控制的跨层路由方案,以及一种基于IEEE 802.11e的MAC协议跨层设计方案。在论文的第四章,提出了一种基于跨层链路失效感知的适用于WMN的动态源路由(Dynamic Source Routing,DSR)改进路由协议——M-DSR,并对其在不同网络状态下的性能进行了仿真分析。结果表明,M-DSR路由协议通过跨层采集MAC层的真实链路状态信息,减少了误判链路失效的次数,降低了路由维护给网络带来的消极影响,从而提高了网络平均吞吐率,降低了路由开销,并且非常适用于WMN。 最后总结全文,并对未来的工作进行了展望。更多还原

【Abstract】 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.更多还原