Research On A FGS Based Congestion Control Mechanism

Real-time transport of live or stored video is one of the predominant parts of streaming media. However, the current best-effort Internet does not offer any QoS guarantees for streaming video. In addition, the heterogeneity of the Internet makes it difficult to efficiently support video multicast while providing service flexibility to meet a wide range of QoS requirements from users. Thus, how to transport streaming video with high quality is currently an important research issue.At first, the thesis introduces the status and development trend of streaming media, analyzes the reason that the traditional video coding techniques are not suitable for network transmission, and then expatiates the FGS video coding technique and its characteristics. On this basis, the thesis presents a FGS based congestion control mechanism. The mechanism determines the sending rate of video traffic based on packet loss model and feedback information about the network QoS provided by RTCP, and then adjusts the sending rate to the available network bandwidth through the use of rate shaping based on the structure of the FGS bitstream, so the optimal video quality is achieved. At the end of the thesis, a streaming video system is developed. The experimental results show that the mechanism can achieve the TCP-friendly behavior and the smooth variation of video quality while the network bandwidth varies.