中南民族大学 硕士学位论文 Ad Hoc网络QoS路由协议的研究 姓名：李娟 申请学位级别：硕士 专业：计算机应用技术 指导教师：陆际光 20070520 中南民族大学硕士学位论文 I 摘 要 A d H o c网络是由一组带有无线收发装置的移动终端组成的一个多跳的临时性 的自治系统。A d H o c网络中的移动终端具有路由和报文转发功能，可以通过无线 连接构成任意的网络拓扑。这种网络可以独立工作，也可以接入 I n t e r n e t 或蜂窝 无线网络。A d H o c网络因其优越的特性为它在军事、民用领域提供了广阔的应用 前景。 路由技术是 A d H o c网络的关键技术，也是影响网络整体性能最重要的因素之 一。A d H o c网络具有无线传输、频繁变化的动态拓扑、无中心、多跳路由等特点， 这使得路由问题变得复杂而难以实现。Q o S保障是 A d H o c网络另一个极具挑战性 的问题，它由于网络状况高度动态变化，带宽及能量受限而难于解决。传统路由 算法满足不了用户的 Q o S要求，需要采取一定的约束路由机制来平衡网络负载， 提高传输效率。近年来，随着多媒体技术、实时业务需求的不断扩大，如何在网 络拓扑动态多变的 A d H o c 网络中提供 Q o S 路由保障成为一个新的研究热点。 本文从 A d H o c网络的基本概念入手，对 A d H o c网络的 D S R ( D y n a m i c S o u r c e R o u t i n g ，动态源路由) 协议进行了详细的分析研究。D S R路由协议是 A d H o c网络 中一种简单有效的路由协议，它使用了源路由机制，每一个分组头部都包含整条 路由的信息。D S R的主要优点在于不需要维护路由信息表，只有在发送数据时才启 动路由发现机制；主机不需要周期性地发送报文，节省了电池能源和网络带宽； 尤其是当没有主机要发送数据时，网络中没有通信开销。但 D S R路由协议本身不 支持 Q o S 机制。 本论文的研究目标是在国内外现有相关研究成果的基础上，改进 D S R路由协 议使其支持 Q o S要求。论文首先深入分析了 A d H o c 网络的 Q o S要求、服务模型和 保障机制，对现有的不同 Q o S路由方案进行了比较研究，针对现有方案的不足， 考虑到在路由过程中时延、能量和带宽的限制，提出了一种支持 Q o S的 D S R路由 方案。论文通过 O P N E T 系统仿真工具搭建了 A d H o c 网络的仿真平台，在此平台的 基础上，实现了 D S R路由协议及本文提出的改进算法。仿真结果指出，本文提出 的 D S R - Q o S路由协议在网络生存时间、时延等方面相对原有协议都有相当程度的 改善，具有较好的 Q o S保障性能，有效地利用了系统资源。本论文还为今后的研 究提出了方向。 关键词：A d H o c网络；服务质量；动态源路由；网络仿真 A d H o c 网络 Q o S 路由协议的研究 II Abstract Ad Hoc network is a multi- hop temporary autonomous system composed of mobile nodes equipped with wireless transceivers and receivers. Mobile nodes in Ad Hoc networks have the function of routing and forwarding packets, and they can form arbitrary network topologies through wireless connections. This kind of networks can not only work independently, but also can be connected with Internet or cellular wireless networks. Because of its superior characteristics, Ad Hoc networks provide brilliant prospects for military and civil applications. Routing technology is one of key technologies of Ad Hoc network. It is also one of the most important factors that affect the whole network performance. The characteristics of Ad Hoc network are wireless transmission, dynamic topology with frequent changes, centerless, multi- hop routing and so on, which make it difficult and complex to solve the routing problems. The QoS guarantee is another challenging problem of Ad Hoc network. It is hard to solve because of highly dynamic changes of network and limitation of bandwidth and energy. The traditional routing algorithm can not meet users QoS requirements, so certain restraint routing mechanism should be adopted to balance the load of network and enhance the efficiency of transmission. In recent years, as the requirements of multimedia technologies and real- time services increasing, how to provide QoS guarantee for Ad Hoc network has been a research focus in current network research. Starting with basic concepts of Ad Hoc network, a deep analysis of dynamic source routing (DSR) of Ad Hoc network was made in this paper. DSR protocol is a simple and effective routing protocol using source routing mechanism. Each packet head in DSR contains information of the entire route. The main merit of DSR lies in that it needn t maintain the routing information table, and the routing discovery will be started only when data are to be transmitted. Followed merit is that nodes do not need to transmit packets periodically. As a result, the energy of batteries and the bandwidth of network are saved. At last, there is little overhead in the network, especially when there is no node transmitting data. However, DSR protocol doesn t support QoS mechanism for itself. Based on existing related research results both at home and abroad, DSR is modified to support the QoS requirement, which is the objective of this paper. Firstly, a 中南民族大学硕士学位论文 III deep analysis of requirements, service models and guarantee mechanism of QoS in Ad Hoc network was made. And a comparison and study of the existing different QoS routing plans were made as well. Considering the delay as well as the limitation of energy and bandwidth in the process of routing, a method supporting QoS for DSR to overcome the insufficiency of the existing plans was proposed. A simulation platform for Ad Hoc networks by means of simulation tools of OPNET has been built. DSR protocol and the modified algorithm proposed in this paper are implemented on this platform. As the results of the simulation shows, the DSR- QoS protocol proposed in this paper has improved the original protocol in some aspects, such as the life cycle of network and delay. The performance of QoS becomes better, and system resources are utilized more effectively. In addition, this paper also proposed the direction for the further research in future. Key Words: Ad Hoc Network; Quality of Service (QoS); Dynamic Source Routing; Network Simulation 中南民族大学 学位论文原创性声明 本人郑重声明：所呈交的论文是本人在导师的指导下独立进行研究所取 得的研究成果。除了文中特别加以标注引用的内容外，本论文不包含任何其 他个人或集体已经发表或撰写的成果作品。对本文的研究做出重要贡献的个 人和集体，均已在文中以明确方式标明。本人完全意识到本声明的法律后果 由本人承担。 作者签名： 日期： 年 月 日 学位论文版权使用授权书 本学位论文作者完全了解学校有关保留、使用学位论文的