Research Of Multicast Routing Protocol Based On Mobile Ad Hoc Networks

With the development of wireless network technology, such as multimedia, more and more services choose Ad Hoc networks as transmission platforms. At present, a large number of multimedia services adopt multicast protocols, can also be said that, providing better networks for multimedia services is the basic of adopting higher performance multicast routing protocol. Therefore, the main research of this paper is the multicast routing protocol in mobile Ad Hoc networks.In order to solve the problem of performance degradation under the heavy load of networks and fast movement of nodes, this paper analyzes the causes and improves MAODV (Multicast Ad-hoc On-demand Multipath Distance Vector) protocol according to different reasons. The main researches are as following:Firstly, as the routing metric of MAODV, minimum hop count ignores the link quality and node energy and so on. It may cause the problems of the imbalance of network loads, insufficient resource utilization and shorter network life cycle under the heavy network loads. A new protocol MAODV-QE (Quality and Energy Based MAODV) is presented. It introduces new integrated routing metric composed of available bandwidth, node energy and hop count. Simulation result reveals that MAODV-QE protocol improved the packet delivery ratio and reduced the delay, especially in the environment of slow movement nodes and large amount of data transmission. At the same time, compared to original MAODV, MAODV-QE prolonged the network life cycle.Secondly, through the analysis of the cause of the lower performance when nodes moves fast, this paper puts forward the MAODV-SPE (Stability Prediction and Energy Base MAODV) protocol based on the MAODV protocol. From the perspective of considering node stability, we analyses the factors that affect the stability of paths and proposes the concept of integrated stability of the node. The new protocol adopts integrated routing metric based on the integrated stability of the node and hop count. During routing strategy, it adds the screening of node’s energy; during routing maintenance, it adopts link failure time prediction mechanism. The simulation result shows, when the nodes move faster, MAODV-SPE is better than MAODV in the two indexes of rate and delay. It confirms the importance of considering node’s stability while the speed of the mobile node is high.