Research On Multicast Technology Over Mobile Internet

With rapid development of mobile Internet, especially the emergence of multimedia services and the rapid development of wireless access technology in recent years, on one hand,the network bandwidth is consumed to a large extent;on the other hand, people are more and more glad to access the Internet anytime and anywhere. In order to use bandwidth more efficiently in the next generation of mobile Internet and reduce network congestion and delay, mobile multicast technology with the advantage of high bandwidth utilization ratio, saving of sender's resources, has drawn more and more attention. However, architecture, algorithms and protocols of mobile multicast are still not mature at the moment and the research of mobile multicast technology is also not complete.According to the problems mentioned above, author put forword an improved mobile multicast algorithm based on the research of mobile Internet and other multicast technologies in this paper.Firstly, the paper introduces the conception and recent status of mobile Internet, and then, some important technology such as MIPv4, MIPv6, as well as the background of mobile multicast technologies, advantages and current situation.After deep analysis of mobile multicast protocols on the mobile Internet, author proposed an improved algorithm --- FRSR (First RMA Second RS) based on the combination of the existing mobile multicast protocol,FHSR and Mobicast. In this algorithm, the conception of RMA(Regional multicast agent) is proposed based on the hierarchical mobile multicast algorithm --- Mobicast, mobile node received the multicast data package from local RMA through tunnel technology after it moves to a foreign network at first, and then join the multicast group through access router or RMA nearby like the way what FHSR did.When MN received data from the new network, it stops to receive data from local RMA.Based on the thinking mentioned above, author uses NS2 as simulation environment to simulate FRSR and some other multicast algorithms, and make comparison and performance analysis among them from multiple aspects. The results of simulation show that the algorithm can shield the mobile node's mobility better in a certain area with little transmission delay, interruption time of service,transmission costs and multicast transmission tree rebuilding ratio.