Streaming Media Transmission Rate Control Mechanism Research

Recent advances in computing technology and high-speed network have made it feasible to provide streaming media services over the Internet. Meantime, with the development of 3G and NGN, streaming media service over wireless networks also has developed greatly.Nowadays, nearly all the streaming media services are based on UDP. UDP is more suitable for streaming media than TCP, but it also has deadly problem. That is UDP does not supply any congestion control, so it can get the available bandwidth in the network it wants, as a result, it can put other flow into the state of starvation for a long time. Moreover, the network may be congested or even collapsed. This problem will be more serious in the wireless network where the environment is worse and the resource is more limited. So, it is urgent to find a new protocol to replace UDP.DCCP protocol has the advantages of TCP and UDP, discarding the shortcomings of them. But the congestion control algorithms in it are designed for wired network, and it is not suitable for wireless network with high link error rate and long transmission delay. This paper combines DCCP with RCS, which is new rate control scheme and suitable for rate control in wireless network, making DCCP more reliable for the streaming media transmission control in wireless networks.Following are the major contents of this paper:1) Principle of Streaming Media technology. Some research on the key techniques about Streaming Media transmission: Application layer QoS, transport protocol, Streaming Server, etc. According to the limitation of application layer rate control, we propose to move it to transport layer and combine with DCCP.2) Research on the DCCP protocol, which is more suitable for Streaming Media transmission, and RCS algorithm, which is more suitable for wireless streaming media transmission. In this paper, we combine DCCP with improved RCS, so that the ability of DCCP in wireless network is improved greatly.3) Implementation of Streaming Media VOD system: Multifunction Set-top-box. In the same time we give some analysis and the relative solution to the problems encountered in this period, which is the foundation for the future work.