An Ameliorated TCP-Friendly Congestion Control Mechanism for Streaming Media

A rate-based TCP-friendly congestion control mechanism - TFRC is discussed in this paper. Its basic structure and some key details are studied. Then an ameliorated algorithm of TFRC is proposed. The ameliorated algorithm colligates modified tfrc throughput equation and the policy of matching the average receive-rate to the average of the send-rate. By matching the actual and expected receive-rates, congestion can often be detected before packet losses occurring. It can help to avoid packet losses and stabilize the transmission rate quicker at session start-up. The application of the modified tfrc throughput equation can estimate the available bandwidth more accurately and improve the smoothness of the streaming media significantly. Simulation on NS2 verifies the validity of our algorithm. Comparing to TFRC, the ameliorated algorithm shows a better performance of real-time and smoothness while maintaining the good performance of TCP friendliness.