Study And Implementation Of Multimedia Real-time Transport With QoS

It's detailed studied Real-time Transport Protocol and designed a RTP-based adaptive QoS mechanism for video transmission in this thesis. Our work is as follows:1. RTP and RTCP arc studied deeply, including their functions, packet formats, payload format design principle, the expansibility of RTCP and characteristics of the protocol;2. We design and implement a extensible RTP Library, which is named ERTPLib and based on RFC3550. ERTPLib can be used in various multimedia session and have the characteristic of high expansibility, short running time and simple interface etc;3. End-system based QoS control technique is studied, including congestion control and error control. The design principle of end-system based QoS control policy is proposed;4. We design a new protocl, named selectively retransmission betimes RTP, which combine RTP with the method of selectively retransmission only the most important data in the bitstream. SRBRTP is a backwards-compatible extended RTP;5. Based on the characteristic of MPEG-4 and payload format design principle of RTP, we present an efficient paeketization algorithm for MPEG-4 vodio bit-streams transprot using RTP;6. A RTP-bascd adaptive QoS mechanism for video transmission is presented. In this mechanism, we adopt improved A1MD rate control algorithm for congestion control and use SRBRTP for error control. It can be learned by experiment results that this mechanism is tep-friendly and can make the best of network bandwidth. Receiver can gel belter play back qualityby using SRBRTP.