Research On Multicast Routing Based On Particle Swarm Optimization In Ad Hoc Networks

Ad Hoc network is a kind of mobile multi-hop, self-organized and distributed wireless network. There is no static infrastructure such as base station as that was in cell mobile communication and they can be quickly built up in anywhere and at anytime. In Ad Hoc networks, all the nodes are equal and free to move. But the features of wireless channel and the mobility of nodes made the routing strategies in Internet networks can not be directly used in Ad Hoc. Adaptive routing protocols must be designed to solve the routing question in Ad Hoc networks. Instead of sending via multiple unicast, multicast reduces the channel bandwidth, time of processing and delivery delay, In addition, multicast gives robust communication whereby the receiver address is unknown or modifiable without the knowledge of the source within the wireless environment. These characteristics are valuable for Ad Hoc network, because the bandwidth and system resource are limited in Ad Hoc network.Multicast routing protocol for Ad Hoc network is main research in this thesis. Firstly we briefly summarize, compare and analysis the existing multicast routing protocols based on the Ad Hoc Network, and give the analysis of MAODV protocol in detail. Secondly, explains the basic principle of particle swarm optimization(PSO) and in order to overcome the disadvantage that the basic PSO could be easy trapped in the local optimum, the simple PSO algorithm and a number of modified PSO algorithms are discussed. Then, an approach based on QoS-MAODV protocol and modified PSO(MDPSO) algorithm(MDPSO-MAODV) is proposed in this thesis to solve the multicast routing problems. Route selection strategy, which based on MDPSO, can update optional route group. Choosing high efficient route, the time of route break and reconstruct is decreased and the successful data transformation efficiency is increased. The simulation experiments on NS simulator demonstrate that the MDPSO-MAODV algorithm is correctness and effective. The result show that the MDPSO-MAODV algorithm can obviously improve packet delivery ratio and reduce end to end delay comparison with MAODV route protocol, and the network has much more better performance than before. Finally, we give the conclusion of our works and suggestions for future research of the field are given.