A Construction And Maintenance Scheme Of Application Layer Multicast System Based On Degree-Constraints NICE Protocol In Mobile Environment

In recent years, while the mobile communication technology is rapid growth, the demand for mobile streaming media service is growing in recent years, which is an opportunity, but a challenge for the streaming media field.The core of mobile streaming media service is combined with mobile network and streaming media technology. There are many characteristics in the mobile network, such as the movability, the frequently of topology changing, low reliability, the dependence on location, limited resources and so on. These features lead to multicast nodes with highly dynamic, limited transmission bandwidth and the unreliability problems. Therefore, how to efficiently transfer streaming media data under the mobile network, and how to provide stable streaming service has always been the hot spot of the current research.The application layer multicast technology can effectively reduce the pressure of the streaming media server, and can also provide massive users with stable streaming service at the same time, which uses unicast forms and provides multicast service, which doesn’t special network hardware’s support, and is easy to deploy. But the application layer multicast has problem of inherent insufficient stability. So, how to construct a stable application layer multicast system is a urgently problem needed to solve.Therefore, in this paper mainly based on the above two points, a construction scheme of ALM system based on NICE protocol in mobile environment is proposed through analysis of our country’s related literature and international research. The scheme make the application layer multicast system more suitable in mobile environment by changing the size of NICE clusters. In order to solve the nodes’ dynamic problem in the multicast system under the mobile environment, we put forward a failure recovery strategy named parent node backup, which based on the mode of reverse control and active alarm in order to maintain the multicast system. When the multicast node failure in the multicast system, the affected nodes can be quickly redirection and restore the multicast service. Besides, we propose to use the similarity of multicast tree to measure the impact of the redirection algorithm on the change of multicast system’s topology, thus evaluating the quick redirection strategy. Simulation experiment is given to show that our multicast system construction’s proposal is feasibility, and the failure recovery strategy is good at rejoin-delay and stability.