Research On Multipath Routing In Mobile Ad Hoc Networks

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,...