Research On Streaming Media In Wireless Networks Based On Markov Decision Process Theory

Nowadays,the demand for video transmission is getting higher and higher.With the development of technology,people pay a growing attention to dynamic adaptive streaming technology based on HTTP(Hypertext Transfer Protocol).DASH(Dynamic Adaptive Streaming based on HTTP)technology is to encode the same video to multiple different quality video files,then divides these files into a lot of segmentations and they are stored in the server.In the process of streaming media transmission,client can select the quality of each segment that is adapted to the current bandwidth.However,DASH does not specify the strategy of selecting a video segment for client,which allows client to decide what strategy to take for efficient delivery,especially for wireless channels with high temporal variability.How to choose the appropriate quality of video segmentation based on the time-varying wireless network bandwidth becomes a research hotspot in today's study area of streaming media transmission technology.Based on the previous work,this paper further studies the model of streaming media transmission system based on Markov decision process and obtains the optimal transmission strategy using this model.This paper focuses on how the segment quality and download time affect the best strategy in the process of adaptive transmission,analyzes the influence of the discretization of the segment download time to the accuracy of the system model.The main contents of this paper are:1.Research on previous work at home and abroad,this paper summarizes the Markov decision process theory(MDP)and further studies the system modeling of streaming media using MDP.2.Based on this model,the optimal transmission strategy in the process of wireless network streaming is obtained.The optimal video segment quality is selected according to the current system state in order to achieve the best user viewing experience.3.Based on the optimal strategy,the simulation program is designed to simulate the validity of the optimal strategy.The system errors due to the state discretizationare analyzed by simulation.