Designing Multipath-Based QoS-Aware Segment-by-Segment Routing Protocols In Mobile Ad Hoc Networks

The Mobile Ad-hoc NETworks (MANETs) are an autonomous infrastructureless network system and a hot research topic in the communication field. However, it is an important and unclear problem to design an efficient routing protocol since the nodes in the network move randomly and the network topology changes continuously. Meanwhile, with the rapid development of network and demand of users, some operations need the guarantee of Quality of Service (QoS) such as delay, bandwidth and so on. As a result, how to make effective use of the wireless network resources to improve the data transmission performance has become a serious problem.We firstly analyse the characteristics of existing routing protocols in MANETs. Then we aim at the extensive applications of large scale networks. A Multipath-Based QoS-Aware Segment-by-Segment Routing Protocol (MQ-SSR) in large-scale MANETs based on virtual dynamic backbone is proposed. The main idea is to divide a long path to be some segments and multiple paths are discovered in each segment in order to satisfy certain QoS requirements. It is a hierarchical structure and the whole network is divided into many smaller square grids of equal size. The most stable super node in each grid is selected to be the cluster-head node, which maintains two routing tables. The inner-cluster routing table is used to route within the cluster and the K-hop vicinity routing table is used to route between neighbouring K-hop vicinities. The proposed protocol utilizes the virtual dynamic backbone to provide high speed and broad bandwidth, which is similar to the wired networks.Then we propose the Node-Disjoint Multipath-Based QoS-Aware Segment-by-Segment Routing Protocol (NDQ-SSR) to improve the fault tolerance. NDQ-SSR is based on MQ-SSR. It divides the long path into some segments and the anchors in each segment are classified into two kinds. Then the multiple node-disjoint paths between anchors are found according to the type of the nodes. We can select the path that satisfies the QoS requirements efficiently and implement the routing maintenance within the cluster conveniently through such method. The theoretical analysis and simulation experiments indicate that the multipath-based segment-by-segment routing protocols proposed in the thesis reduce the routing management overhead and the cost of routing maintenance efficiently. It also advances the expansibility, reliability, and invulnerability of the network. Meanwhile, the multiple paths provide a powerful guarantee for the QoS requirements.