Research On Transmission Policy Of Streaming Media Over Hybrid Network

Since streaming media makes the applications of internet more and more entertaining andinteractive, traditional internet has become much more abundant. Streaming media has been themain web-service of the internet, and the research on scheduling technology of streaming mediahas become one hot topic, the way "how to ensure the quality of service while providing theservices of streaming media to massive clients", directly affects the user experience. And thescheduling technology of streaming media is an important means to solve the problem.Considering both of the demand boom and the bandwidth shortage, this thesis focus ontransmission policy of streaming media over hybrid network, and the major work andcontributions are as follows:1. Analyzing the performance of the system for streaming media, and deriving the factorsthat affect the performance, this chapter provides theoretical guidance for the positio ning of theresearch. First, this chapter creates a model of user needs from the system perspective, makes aperformance analysis of the supply and demand for three systems with different schedulingtechnology, and then explores the impact of scheduling technology for the service scale. Second,this chapter analysis the delay of end-to-end transmission and the distribution efficiency of theentire system, and then explores the impact of scheduling technology for the quality of service.Last, the conclusions of the analysis are summed up to provide theoretical guidance for thefurther research.2. Due to the demand boom, the existing policy can not guarantee the reception quality ofthe data while keeping the high distribution efficiency. To solve this proble m, this chapterpresents a state model based on node adaptive transmission mode selection algorithm. First, thenode status model, using the data reception quality and overall state values, is proposed todeterminate the node state. Then, an adaptive algorithm is proposed to select the transmissionmode, combined with the existing data buffer model and topology of hybrid network. Finally, thesimulation results show that the algorithm improves the system performance of large-scale andefficient distribution, and ensures the quality of the data received by controlling the server load,but also improves scalability.3. Face of the bandwidth shortage, the existing policy cannot ensure a good user experiencewhile making the efficient use of bandwidth. To solve this problem, this chapter presents a newbandwidth adaptive technology to prioritize the video fluency and reduce the zigzag qualityswitching. This method is the improvement of existing priority algorithm, give priority toensuring the fluency of video. And on this basis, it adjusts the position of drop_threshold toreduce video quality oscillation. The simulation results show that the method can improve theuser experience, by giving the priority to ensuring the fluency of the video and to reducing thezigzag quality switching.