Research On Video Transmission Based On Improved Slow-start Algorithms Of TFRC Protocol

With the rapid development of Internet, remote medical treatment and remote education, video conference and other multimedia information becomes possible, but the contradiction between the bandwidth limitation of real-time transmission network and the amount of data transmission, makes many business especially real-time multimedia transmission business get great restrictions. In order to making real-time transmission of multi-media information on the network more effectively, this thesis analyzed real-time transmission technology and congestion Control theory, and improved the congestion Control strategy of TFRC protocol. This is proved to improve the video real-time transmission quality effectively.The main works of this paper:Firstly, as the slow responding to network congestion, making the network delay jitter replace lost events as the warning signs of congestion, this method effectively solved the phenomenon of packet dropping, which caused by the above problem.Secondly, without considering the influence of network queue, TFRC protocol has certain limitation in slow start, and has influence on smoothly sending rate. So the improvement of slow start is carried out, which adjusted sending rate according to the network status, and improved the jitter of rate.Thirdly, in order to use Evalvid combining with NS2 (Networking Simulator, version 2) to assess the quality of system, improved the simulation module, and maked Evalvid to support NS2 simulation environment. So it can verify the improved protocol, and evaluate the quality of video transmission system at the same time. Experimental results show that the proposed algorithm can ensure real-time video transmission, and achieve the expected design.