【作者】 高圣国；

【导师】 王汉兴；

【作者基本信息】 上海大学 ， 运筹学与控制论， 2008， 博士

【摘要】 近20年来,随着通信手段的丰富和Internet的普遍应用,新业务层出不穷,促使通信技术飞速发展,在需求的强大激励和技术的有力支持下,通信领域经历了从窄带到宽带、从有线到无线、从固定到移动的巨大变化。通信领域里标准化极为重要。IEEE 802标准化工作组致力于接入网络的研究,其中无线接入网络主要有IEEE 802.11局域网、IEEE 802.15个域网、IEEE802.16城域网、IEEE 802.20广域网,另外IEEE 802.21工作组负责研究IEEE802系列接入网络之间的互操作问题。IEEE 802标准化工作与相应的协会和联盟相配合,促进规范的产业化。与IEEE 802.11工作组相对应的是Wi-Fi联盟,与IEEE 802.16相对应则是WiMAX论坛。IEEE 802.11属于无线局域网范畴,实现“最后100m”接入。作为接入网,无线局域网既可以接入核心网,作为固定网的无线延伸,也可以与具备高速性能及更大覆盖范围的移动技术相结合,作为2G和3G移动网的分组接入网。从市场来看,这是到目前为止最为成功的无线接入系统。Inter将其功能内嵌于笔记本电脑内,为这一技术的广泛应用提供了更大的便捷。IEEE 802.16属于无线城域网范畴,实现“最后一公里”接入。IEEE 802.16是在IEEE 802.11有了初步实践后,对新的需求进行了充分分析,并在IEEE 802.11技术上进行改进与增强而产生的。IEEE 802.16标准的发布有着重要的意义,它是第2代宽带无线接入系统产生的标志,并将成为宽带接入的主流系统。Ad Hoc网络是没有中心实体的自组织网络,依靠节点之间的相互协作在移动、复杂多变的无线环境中自行组网。移动Ad Hoc网络的特点是组网灵活性强、支持移动性、易于迅速展开、系统抗毁能力强。通过建立数学模型来分析通信协议的性能是研究协议的一个重要方法。本文给出IEEE 802.16在PMP的工作模式下非实时的和尽力服务的数据流竞争带宽的马尔科夫模型,分析了的带宽请求的延时与竞争窗口的大小、用户站的数量和每帧中的带宽请求时隙数以及最大的重传次数之间的关系。IEEE 802.16支持QoS,但没有给出具体实现方案,而是让商家根据不同的需要自行开发,我们在NS-2中实现了一个基于优先级的支持QoS的带宽调度算法并通过模拟验证。关于IEEE 802.11 MAC层的媒体接入控制机制在饱和条件下的模型已经有很多,本文给出了一个饱和条件下的闭队列模型和非饱和条件下的马尔科夫模型,计算了平均延时这一性能指标,并通过网络模拟验证了模型的有效性。针对局部拥塞可能导致路由协议的性能下降,我们对Ad Hoc网络中经典的AODV路由协议作了改进。本文的结构如下:在第一章里,我们简要介绍了Ad Hoc网络和IEEE 802.16、IEEE 802.11标准,以及广泛使用的网络模拟软件NS-2。在第二章,我们建立了IEEE 802.16在PMP模式下对非实时和尽力服务数据流竞争带宽的马尔科夫模型,对平均延时进行了分析,模拟结果表明模型是比较精确的。第三章里,给出了IEEE 802.16一个基于优先级的支持Qos的带宽调度算法,并在NS-2中编程实现了该算法。在第四章,我们给出了IEEE 802.11分布协调功能(DCF)在饱和条件下的闭队列模型,并给出了平均延时的计算公式。第五章里,研究的是IEEE 802.11分布协调功能(DCF)在非饱和条件的马尔科夫模型。在第六章,我们改进Ad Hoc网络的AODV路由协议,并通过模拟比较了改进后与改进前的性能。第七章是结论。更多还原

【Abstract】 Over the past 20 years, with the means of communication to enrich and the universal application of the Internet, an endless stream of new business, a powerful incentive in the demand and the strong support of the technology, communications experience from narrow-band to broadband, from cable to wireless, from fixed to mobile of the tremendous .Standardization in the field of communication is extremely important. IEEE 802 Working Group to standardize access network research, LAN IEEE 802.11, IEEE 802.16 MAN, and WAN IEEE 802.20, and IEEE 802.21 . IEEE 802 standardization work with the corresponding association and the Union effort to promote the industrialization of norms. With the IEEE 802.11 Working Group corresponding to the Wi-Fi Alliance, corresponding with the IEEE 802.16 is WiMAX Forum.IEEE 802.11 wireless LAN area, to achieve the "final 100 m" Access. Wireless LAN can access the core network, fixed network as a wireless extension, and may also have a high-speed performance and greater coverage of mobile technology, as 2G and 3G mobile network packet access network. From a market perspective, this is by far the most successful wireless access system. Inter embedded it in laptops, providing greater convenience for the broad application of this technology.IEEE 802.16 wireless MAN areas, to achieve the "last mile" access. It is made after initial practice of IEEE 802.11 and base a full analysis on the new demand. The release of IEEE 802.16 standard is of important significance, it is the first second-generation broadband wireless access system to produce signs, and will become the mainstream broadband access system.Ad Hoc network is self-organizing wireless network in the complex and dynamic environment. Mobile Ad Hoc network is characterized by strong network flexibility to support mobile, easy to quickly start system and stronger resistance to destruction.Through the establishment of mathematical models to analyze the performance of communication protocol is an important method. In this paper, we give Markov model of the competitive bandwidth for IEEE 802.16 in PMP mode, analysis the relationship between the delay and competition window size, the number of users stations and the slot number in each frame . IEEE 802.16 support QoS, But it did not give concrete realization of the programme, to the different needs of businesses under their own development, we realize it in NS-2 and verified by simulation. There are a number of models On IEEE 802.11 MAC under saturated condition, this paper gives a closed queueing model for IEEE 802.11 under saturated condition and a Markov model for IEEE 802.11 MAC under non-saturated condition, calculate the average delay , the validity of the model is verified. Against local congestion could lead to decline in the performance of routing protocols, the classic AODV routing protocol in Ad Hoc networks was improved.This paper is structured as follows:In the first chapter, we briefly introduced the Ad Hoc networks and IEEE 802.16, IEEE 802.11 Standards, as well as network simulation software NS-2. In the second chapter, we have established a Markov model for IEEE 802.16 in PMP mode, simulation results show model is more accurate. Chapter III, we give a support Qos bandwidth scheduling algorithm for IEEE 802.16, and implemente it in NS-2. In the fourth chapter, we give a closed queuing model for IEEE 802.11 DCF under the saturated condition , and gives the formula for calculating the average delay. Chapter V, for IEEE 802.11 DCF under the non-saturated conditions, a Markov model is gived. In the sixth chapter, we have improved AODV routing protocols . Chapter VII is the conclusion.更多还原