Multicasts The Route Agreement Based On The Ad-hoc Network The Research And The Realization

As information technology continues to develop, people's demand for mobile communication is growing. In recent years, mobile communication technology has developed rapidly and popularized widely. At the same time, new technologies are emerging frequently. However, the mobile communication technology often mentioned are generally centralized control, such as traditional cellular wireless network systems, usually based on pre-erection of the network infrastructure and the central station to run.Ad hoc network is a special kind of wireless mobile communications network and a dynamic self-organized network system composed of a group of devices with a wireless transceiver for mobile terminals. It is characterized by multi-hop wireless links, no fixed facilities and a distributed management. Compared to the traditional cellular network, Ad hoc wireless network does not have base stations, its mobile terminals in the network distributed operates, its routing and message can forward, and any wireless connection can form network topologies. Such networks can not only work independently, also connect to the Internet backbone network or cellular wireless network. Their application environment includes fighting, rescue work in disaster relief, and expedition adventure in the communications and so on.Built upon the study Ad hoc network multicast routing of MAODV and Internet access agreements algorithm of Jelger, the thesis focuses on the issue that when Ad hoc network accesses for Internet, mobile node dynamic is easy to switch frequently in the gateway. Inadequacy of the algorithm of Jelger is that if the nodes with minimal hops accessing gateways, it will cause frequent switching. If the network prefix maintains continuity, although frequent switching can be avoided, yet it will lead to unnecessary delay.By an improved algorithm, when the gateway node received the information, first judgment can be made whether the same network prefixes have difference or not. If so, the smallest number of jump will be used to connect the network gateways; if not, the number of jump saved will be calculated between the original and the new jump. As long as achieved the above threshold, it can be switched. Otherwise we continue to access the gateway. This thesis applies OPNET simulation tools to analyze and compare the original algorithm and the improved algorithm.