Research On Mobile Ad Hoc Network Routing Protocols

Ad Hoc network is a multi-hop provisional autonomic system that is composed of a set of moving terminal with routing function, whose nodes can form a network with any topology by wireless link. As an important factor that can impact the network performance, the routing protocol is the key element of Ad Hoc network. Thorough and comprehensive researches on routing protocol will provide the application of moving organized network with significant scientific background. By using NS2 (Net Simulator version 2) simulating platform, this dissertation studies up on the routing protocol. The main contents of this dissertation are as follows:Thorough researches are made on the routing protocol of Ad Hoc network and its quality indexes, and contrastive analyses are made among some of the typical routing protocols. The AODV routing protocol is detailedly analyzed and is simulated on the NS2 simulating platform. The results indicate that the AODV routing protocol is easy to expand and has a prompt astringency, but its performance under a heavy load is rather bad.According to a branch of military communication, the small unit communication and control network, a corresponding network model is set up to optimize the AODV routing protocol. By establishing routing ahead, limiting the amount of control package and improving on the mechanism of block avoiding, the new routing protocol can reduce the missing rate of packages shorten the network transmitting delay, thereby increase the capability of the network.. Through simulations on the NS2 simulating platform, the performance of the new routing protocol is compared with the original AODV routing protocol, and is proved to have a enhancive capability.Based on the multi-stream encoding and multi-path transmission of video multimedia information, the AOMDV, a multi-path form of the AODV routing protocol, is put forward and evaluated. In order to make itself more adapt to the transmission of multimedia information, the AOMDV provides reliability based on link state estimate, advance link alarm and a dynamic adaptive method of routes choosing, all of which are simulated on the NS2 simulating platform. The results indicate that the new optimized routing protocol is more effective to keep the network running.