Research Of Rate Feedback Control Algorithm For Streaming Media

With the rapid development of multimedia technology, real-time streaming media applications over the Internet are becoming more and more popular. In contrast to bulk data, streaming media has rigid requirement of quality of service (QoS, such as bandwidth, delay, and data loss). At present, most of streaming media applications are based on UDP protocols and lack congestion control schemes, which will lead to network congestion and degrade QoS of streaming media. Therefore, it becomes important to design a rate control mechanism that can avoid network congestion and be suitable for transporting streaming media.Many proposed rate control mechanisms for streaming media mainly focus on congestion, but do not take into account the utilization of bandwidth, and requirement of QoS. Another rate control scheme based on flow control and control theory has been proposed. It adjusts streaming media traffic sources' data sending rate by using queues of router. It can effectively prevent congestion and improve the utilization percent of network. But most of these schemes didn't flexibly adjust to the great variations in the number of user and round trip time as well as the presence of uncontrolled traffic in the Internet.This paper presents the existed rate control mechanism for streaming media and analyses the insufficiency. Then the modeling method of rate control mechanism is described. Next two schemes based on fuzzy logic control are proposed for streaming media to efficiently avoid congestion. The proposed algorithm can efficiently handle congestion, decrease the data loss, and ensure the smooth of traffic sources' data sending rate. So it can improve the QoS of streaming media. Finally the performances of different algorithms are verified and compared in Matlab/Simulink. The simulation results show that the algorithms improve the transient performance, and increase robustness against uncertainty such as time delay, variety of number of users as well as the presence of uncontrolled traffic in the Internet, and improve network's utilization.