The Research Of DSR Routing Protocol In Ad Hoc Wireless Network

In recent years, Ad hoc network has drawn more and more attention for its flexibility and usefulness, and it has broad prospects for development. However, as Ad hoc network is different from traditional network, a lot of technology can not be directly applied to Ad hoc networks. As a result, main technology is still at the research stage, among which, routing protocol is one of the hot spots in the research of Ad hoc network. Its performance depends on routing protocols. Ad hoc network typically uses routing techniques similar to those in wired networks. After deep research, it is realized that this kind of routing techniques could not adapt to the volatility of wireless channel and the dynamics of topology. The on-demand routing protocol Dynamic Source Routing (DSR) is a good performance protocol in mobile Ad hoc networks. However, the defect of it is that it is not quick enough to adapt the fast changing topology of the Ad hoc networks, and also the routing protocol which build and rely on single path can be disconnected easily, reconstructing routes results in larger end-to-end delays. These result in the low efficiency. To solve the problem, DSR is optimized in this paper from different aspects.First of all, this paper describes the parameters of DSR protocol, and discusses the dependence of each parameter of DSR protocol. Because of the different scenarios, parameters in DSR protocol can not be the same. For the chain topology, this paper modifies the parameters of DSR protocol. The test results show that the performance of the protocol with modified parameters is better than DSR protocol with the default parameters.What is more, this paper proposed opportunistic routing mechanism. This mechanism uses RREQ message and RREP message to establish forward list. Only nodes among forward list could forward the packet. The nodes in the list are set priority by their hop to destination. The mechanism chooses the best node to forward packet. The forward list is established and maintained by source node. The intermediate nodes do not have to maintain routing information. In the end, the paper compared the performances of opportunistic routing and DSR from time-delay jitter and packet delivery, the test results show that the performance of the opportunistic routing is better than DSR protocol.Last of all, this paper uses multipath routing protocol to optimized DSR protocol. The on-demand routing protocols which build and rely on single path can be disconnected easily, reconstructing routes results in larger end-to-end delays. Split Multipath Routing (SMR) algorithm building two available routes between source and destination nodes is better than single path in Ad hoc networks, but shows higher routing load because of generating more control packets while building multiple routes. This paper proposes the optimization of SMR protocol in Ad hoc networks, and reduces the number of the control packets. The DSR and SMR protocol are compared with the optimization protocol under NS-2 in routing load, packet delivery and average end-to-end delay. The results show that the performance of the optimization protocol is better than the DSR and SMR routing protocol.In a word, DSR protocol is optimized from three different aspects in this paper, and DSR protocol is compared with the optimization protocol under NS-2 and in outdoor scenes. The test results show the performance of the optimization protocols are better than DSR protocol.