Research On Adaptive Streaming Transmission Technology For Heterogeneous Wireless Networks

With the fast development of computer technology and mobile communication technology, multimedia services have taken a large percentage in the mobile internet traffic. More and more users tend to enjoy a variety of rich multimedia applications on their mobile devices, therefore, streaming media technology have attracted much attention of home and broad researchers, operators, service providers, etc. It is a great challenge for them to provide users with high-quality, stable, and continuous service in the dynamic heterogeneous wireless networks environment. Adaptive streaming technology, which is the best solution to the above problem, is introduced during transmission to dynamically adjust the quality of service content according to the changing network environment and user demand to ensure user service experience. Therefore adaptive streaming technology has become a hot topic in streaming media area.At first, mobile streaming media technology is briefly introduced in this thesis. Then the following three aspects are mainly studied for the current problems in adaptive streaming media transmission system.(1) Primarily, the significance of Qo E on the real-time transmission system is illustrated based on introducing the conception of Qo E. Then the advantages and disadvantages of adopting adaptive technology to the server and client in the streaming media transmission system is analysed respectively, and then on the base of this, an algorithm of adaptive real-time video transmission based on the user experience is proposed.Finally the end-to-end real-time transmission system is built for testing and validation.(2) The adaptive technology is applied to multipath concurrent transmission system and an available bandwidth-based multipath concurrent adaptive scheduling algorithm is presented to dynamically perform packets scheduling and path management in light to the ratio of available bandwidth. The feasibility of the algorithm is verified by the simulation, the results show that the algorithm can improve system throughput and utilization effectively.(3) The importance of buffer queue management in end-to-end video communication is analyzed at the beginning of this section and then an adaptive buffer management algorithm based on queue prediction is proposed, which combines with adaptive buffer management and adaptive media playback technology. Simulation results indicate that the algorithm can reduce the interrupt frequency and frame loss rate of video effectively and ensure the end-to-end delay within the acceptable range at the same time. Finally, conclusions are given and also future work of our research is presented.