【作者】 肖克江；

【导师】 熊忠阳；

【作者基本信息】 重庆大学 ， 计算机系统结构， 2011， 硕士

【摘要】 移动Ad hoc网络是一种特殊的无线移动网络,其路由设计问题是无线移动网络领域的热点问题。随着制造工艺和设备性能的不断进步以及基础理论研究的不断深入,移动Ad hoc网络开始从军用进入商用和民用领域,如会议数据分发、数字化农业、保健医疗、智能公路等。因此如何进一步提高路由协议的性能是当前急需解决的重要问题。本文的主要研究对象是无线自组网按需平面距离矢量路由协议(AODV)。由于其实现简单、开销小,是目前的研究热点。本文主要对AODV协议进行了分析和研究,探究了其自身的局限性,并在文中给出了解决方案。本文的主要工作和研究成果如下:①对AODV和AOMDV的链路探测机制进行了研究。AOMDV是一种基于AODV的多径扩展协议,它维护多条备份路径,在主路径失效时可以使用它们。AODV和AOMDV协议都包括两种链路探测方法:HELLO消息探测和链路层(802.11)反馈。在本文中,对AODV和AOMDV的两种链路探测机制进行了对比分析。实验结果表明,在AODV和AOMDV路由协议中,通过链路层反馈进行链路探测比利用HELLO消息进行链路探测具有更高的数据分组投递率、更低的归一化路由开销、更高的端到端平均时延和路由发起频率。②对AODV路由协议的本地修复机制进行了研究。在本文中,主要对AODV路由协议中的本地修复的最大修复长度进行了分析和研究。对于最大修复长度,我们是以原协议的最大修复长度(MAX_REPAIR_TTL)为中心,分别取7个值。实验结果表明,最大修复长度越大,则协议的数据分组投递率越高、归一化路由开销越大、端到端平均时延越长、路由发起频率越高;最大修复长度越小,则协议的数据分组投递率越低、归一化路由开销越小、端到端平均时延越短、路由发起频率越低。③对AODV路由算法进行优化。在本文中,主要根据两跳路由信息和一跳邻居信息,对AODV路由算法进行优化,使得AODV路由协议能够自动适应网络拓扑的动态变化,能够对活动路由进行动态优化。实验结果表明,改进后的协议在数据分组投递率等性能方面比原协议的效果要好。更多还原

【Abstract】 Mobile Ad Hoc Network is one kind of special wireless mobile network, and its routing design is a hot topic in the field of wireless mobile network.With the continuous progress of manufacturing processes and equipment’s performance and with the depth study of basic theory, mobile Ad hoc network started from the applications of military into commercial and civil areas, such as meeting data distribution, digital agriculture, health care,smart highways and so on. So how to further improve the performance of routing protocols is the current important issue that needs to be resolved.The main object of study is AODV in this thesis. Because of its simple and low overhead, it has become a current hot issue. Through the analysis and study about AODV, its own limitation is explored and the solution is given in this thesis.The main achievements of this thesis are as follows:①Some researches on the link detection mechanism of AODV and AOMDV are done. AOMDV which is based on AODV is one kind of multipath extended protocol, and it maintains multiple backup paths.When the primary path fails, backup paths will be used.Both AODV and AOMDV protocols include two kinds of link detection method: HELLO messages detection and link layer (802.11) feedback. In this thesis,comparative analysis researches on link detection mechanism of AODV and AOMDV are done. Experimental results show that the detection of link layer feedback mechanism has higher data packet delivery ratio、lower normalized routing load、higher end-to-end average delay and higher route discovery frequency than HELLO messages in the AODV and AOMDV routing protocols.②Some researches on the local repair of AODV routing protocol are done. The maximum repair length of local repair about AODV is analyzed and studied in this thesis. As for the maximum repair length, the maximum repair length of the original protocol(MAX_REPAIR_TTL) was set as the center, taking seven values respectively. Experimental results show that the greater the maximum repair length is, the higher the data packet delivery ratio is, the greater the normalized routing load is, the longer end-to-end average delay is and the higher the route discovery frequency is; the smaller the maximum repair length is, the lower the data packet delivery ratio is, the smaller the normalized routing load is, the shorter the end-to-end average delay is and the lower the route discovery frequency is. ③AODV routing algorithm is optimized. In this thesis, based on two hop routing information and one hop neighbor information, AODV routing algorithm is optimized, making the AODV protocol automatically adapt to the dynamic changes of the network topology and active routes be optimized dynamically.Experimental results show that the improved protocol has better results than the original protocol in data packet delivery ratio.更多还原