【作者】 安辉耀；

【导师】 卢锡城；

【作者基本信息】 国防科学技术大学 ， 计算机科学与技术， 2005， 博士

【摘要】 移动自主网络(MANET)是由移动结点通过分布式协议自组织起来的一种无线网络。对于一些没有固定基础设施、没有有线网络和管理中心的地方，MANET可能是唯一可选的通信工具。它具有部署方便、灵活的特点，具有诱人的应用前景。然而移动性容易导致拓扑改变，可能中断现有的路径，单路径路由算法很难快速地适应拓扑改变、有效地发现和维护路径。基于MANET的平面结构在源和目的之间可存在多条路径，人们提出了多路径路由技术。但是已有的多路径技术还存在明显不足：1)已有多路径路由协议，主要研究其容错性，流量主要分布在主路径中，它仅在主路径失效时，才将数据流切换到备用路径中去，不能适应应用对吞吐率和负载平衡的要求；2)使用平面结构，处理动态拓扑改变的能力差；3)平面式结构在结点数目增多时的多路径的路由开销增大、可扩展性差。 论文在分析MANET网络特性及已有算法的基础上，应用跨层设计思想，集中研究了MANET中多路径路由的几个关键技术，包括多路径路由的可扩展性、多路径传输的可靠性及多路径动态拓扑的自适应性等问题等。论文主要工作是： 1)可扩展的多路径路由算法研究 平面式结构的MANET在结点数目增多时的路由开销增加很快，可扩展性较差。论文引进分簇的方法来提高网络的可扩展性。一方面利用基于簇的层次结构动态处理网络拓扑变化，减少路由管理开销和路由维护的代价；另一方面利用多路径并发传输增大了吞吐率，可以实现拥塞避免和负载平衡，优化网络带宽的使用、提高共享信道的利用率。 ■ CBMRP算法-一种基于簇的多路径算法 算法的基本思想是采用单层簇结构来处理网络拓扑变化，采用分布式推进、逐段查找的方式进行路径查找。该算法的优点是分簇结构简单，部署方便，在规模较小的网络中采用分布式逐段查找方式查找路径可以减少泛洪时引起的通信开销。 ■ CMDSR算法-基于簇的动态源多路径路由算法 对于大规模较网络，CBMRP采用逐段查找路径的方法存在路由查找开销大的问题，且采用单层簇的简单结构存在可扩展性较差的问题。动态源路由(DSR)算法开销小，但它在泛洪时会产生大量路由控制开销。本文基于DSR算法，将网络分成两级簇(单元簇和中心簇)层次结构，以提高网络的可扩展性，同时将路由发现功能迁移到中心簇层来实现，以防止类似DSR路由发现过程的泛洪，实现路由查找开销最小化。CMDSR能够有效地处理结点数量增大和结点密度增大的问题。此外，CMDSR通过选择可靠的路径和发送端到端的可靠性软保证的方法提高了可靠性。 2)可靠性多路径路由算法研究 数据传输可靠性对多路径路由的性能具有重要的影响。论文集中研究了可靠性的两个更多还原

【Abstract】 Mobile Ad Hoc Network is a wireless mobile network consisting of a large number of mobile nodes using distributed protocols. MANETs may be the only solution in many situations where instant infrastructure is needed and no central backbone system and administration exist. MANET provides a feasible way for communication and information access. Therefore, the unmatched advantage and inherent nature of MANET have led to extensive application foregrounds. Mobility of wireless networks nodes causes frequent topology changes and may break existing paths in MANET. Unipath routing protocols are hard to keep up with the frequent topology changes. The multipath routing is proposed as there exist multiple paths between the source and destination pair in MANET plane structure. However, some limitations do exist: 1) Almost all existing multipath routing protocols focus on fault-tolerant problems. They distribute the traffic mainly on the primary route. It is only when this route is broken that the traffic is diverted to alternate routes. Clearly, they can not meet requirements for throughput and load-balancing of application. 2) Because of the plane structure, the ability of disposal topology change is poor; 3) the routing control overhead will increase significantly when the number of the network nodes increases.By analyzing the requirements and challenges of MANET multipath routing and some limitations of existing work, and introducing cross-layer design idea, this dissertation first focuses on the problems of scalable multipath routing, reliable transmission multipath routing, dynamic-topology-based adaptive traffic distributing multipath routing and so on.The major contributions of this thesis include:(?) Research on scalable multipath routingMANET with the plane structure will increase routing control overhead; the scalability problem is likely to happen. This dissertation proposes clustering method to improve the scalability of network. On one hand, an adaptive mobile cluster algorithm can sustains the mobility perfectly and maintains the stability and robustness of network architecture. On the other hand, utilizing multiple paths for parallel transmission can improve the throughout, avoid congestion and achieve load balance.1) CBMRP algorithm-Cluster-based Multipath Routing ProtocolCBMRP uses single layer cluster structure to deal with network topology changes, and uses the distributed push and stepwise approach for routing discovery. Its advantages are simple hierarchical structure, easy deployment, and the flooding communication overload is reduced by distributed stepwise routing discovery in small network.2) CMDSR algorithm-Cluster-based Multipath Dynamic Source RoutingFor large-scale networks, CBMRP is too complicated, and the overhead is too expensive,更多还原