The Research Of Active Queue Management For Video Transmission

Congestion control and quality of service are closely related research areas, the effectiveness in congestion control is a key factor to ensure quality of service of the network. End to end TCP based algorithm can not use the network information during the transmission process to handle congestion control effectively. So in recent years, the focus of research has been gradually shifted to the router aspect, especially in active queue management design. Meanwhile, with the rapid development of network technology, the users are now demanding more and more real-time multimedia applications, how to develop, plan, transform the existing network to meet such changes and such diverse needs of customers has become a pushing question to researchers and industry corporations.After a brief summary of existing active queue management algorithms, several typical model based active queue management algorithms are analyzed. Focused on the MBIO algorithm which based on the BLUE algorithms working for DiffServ, we have studied and compared the MBIO performance with other algorithms. Considering the features of MPEG-4/H.264 video encoding, a new algorithm named MBIO-C is proposed. The Simulation results of NS2 show that the improved algorithm can improve the quality of video transmission effectively; we also compared our MBIO-C algorithm with RIO-C algorithm which based on the RIO algorithm. The main contents of the paper include the following.First, the paper briefly introduces the basic principles of streaming media and video transmission, and analyzes the advantages and disadvantages of the integrated services model and differentiated service model.Secondly, the paper briefly introduces the basic concepts of congestion control, several typical active queue management algorithms are analyzed systematically, concentrated on the analysis of several differentiated service-based active queue management algorithms. In particular, the differentiated services oriented active queue management MBIO algorithm based on and improved the BLUE algorithm is analyzed, and it performs more stablely with the variation of buffer queue length compared with the RIO algorithm.Finally, based on the MBIO algorithm, and considered the features of MPEG-4/H.264 video encoding, we modified the active queue management MBIO algorithm into a three drop-priority MBIO-C algorithm. As the fact that latency has a big impact on streaming media, the timeouts early detection has also been included in the MBIO-C algorithm to reduce the timeout probability of received video data packets.