Research On Constructing Algorithm Of Application Layer Multicast Tree Based On Heterogeneous Nodes And Latency Model

At present, the rapid development and advancement of mobile Internet technology promoted the rapid increase of the comprehensive performance of mobile terminal, the propulsion of 4G network commercial deployment and the gradually improvement of terminal equipment function pushed the exponential increase of end user, and the end user demand for mobile streaming media is growing fast at the same time. Therefore, to provide users with stable and efficient streaming media service is essential under the background of great development in the mobile Internet. Most of mobile streaming media applications send packets by building the multicast tree which can transmit data, copying the data of source node, providing efficient service for other nodes. Therefore, it is fatal to discuss the methodology of building a multicast tree with stable data transmission capacity and low delay.Mobile streaming media application is focused on the combination of the processing capacity of the mobile Internet and the transmitting and processing technology of streaming media, developing the highly efficient mobile application products, ALM(Application Layer Multicast) protocol, as the key technology of mobile streaming media application software, do not need the underlying router to support agreement when compared with the traditional IP multicast network, it just needs the terminal node to copy and transmit data, it enjoys the advantages of flexible usage, low cost of commercialization, large-scale deployment and promotion with convenience and so on, but the mobile client also has disadvantages such as poor stability, large transmission delay, unreliable transmission, frequently changes of network topology, limited storage resources and so on, largely constraining the use of ALM, therefore, how to reduce transmission delay of multicast protocols and build ALM tree with high stability become the problem which is urgently to be solved in the ALM protocolsBased on the above problems, the article is to improve the ALM protocol based on the goal of building high stability multicast tree through heterogeneous nodes and reducing the transmission delay of multicast tree, the article's innovation is presented in the following two aspects:First of all, the paper puts forward a kind of ALM construct algorithm build time operation to HSHN(High Stability-based on Heterogeneous Nodes) via multicast node performance and online time operation, and backup the recovery method of key parent ALM tree. Firstly, making the model, building the high stability multicast tree based on heterogeneous nodes and putting forward the recovery method of multicast tree, and then analyzing the model, demonstrating the methods to guarantee the relatively high stability of multicast tree. The simulation results show that the proposed HSHN algorithm with high stability can quickly build a multicast tree with lower time delay for nodes to join in, and can quickly restore the multicast tree.Secondly, defining the transmission delay model of the ALM protocol, understanding the causes of transmission delay of ALM and the key factors that affect the ALM Delay, and discovering that processing power of terminal node, the stability of ALM Tree, the size of the node's degree and the length of transmission path brought by the depth of the Multicast Tree.etc all affect the transmission delay of Multicast Tree. According to these characteristics, this paper puts forward a algorithm by the online time of nodes and processing capacity to determine node degree, building ALM Tree with lower latency and load balance by time delay. The simulation test proved that the ALM Tree constructed by MDBT (Minimum Delay the Balance on ALM Tree) can transmit data effectively at a relatively low Delay.