Ip Network Video Multicast Key Technologies

With the rapid increase of network video applications, network bandwidth usage and congestion are getting more attention of industries and academia. How to improve the video transmission quality efficiently becomes a hot topic in the fields of Internet. Multicast can save bandwidth usage and avoid the problem of sender bottleneck, so it becomes an essential method in many video applications. Reliable video multicast deals with multicast protocols, network architecture, flow control, adaptive coding, and etc. And these researches are hard and attractive.This dissertation centers on the QoS assurance of video stream multicast and is based on the study of multicast and stream media techniques. I proposed reliable IP multicast policies for switched Ethernet videos, multicast send rate control method, and relative algorithms on wireless ad-hoc multicast. The simulation results and the real effect of the projects have shown their effectivity and reliability. The main work is summarized as follows:1. Propose and implement the reliable multicast policy on network DTV, which is composed of error correction and multicast congestion control. The key of reliable video multicast is how to reduce packet loss and recover loss packets. About error correcting, we use a hybrid method of forward error correction (FEC) coding and interleave technique. About congestion control, we decrease packet loss and congestion by controlling the send rate of server. The two schemes have been already used in network DTV systems in 3Tnet. The real test results proved it could improve video quality well.2. Propose an Improved TFMCC Sending Rate Control (ITSRC) for network DTV servers. Network congestion is the main reason that caused packet loss in video transmission, so video multicast stream should be adaptive to network congestion. Considering TFMCC and the basic required send rate, I implemented network-adaptive send rate control. The simulation result shown that the proposed scheme is well network-adaptive and effective in decreasing packet loss caused by congestion.3. Propose a Buffer-based Network-adaptive Multicast Rate Control approach (BNMRC). Its start is to suppress overflow and underflow of the send buffer. Firstly send...