Supporting non-adaptable multimedia flows by a TCP-friendly transport protocol

This work studies TCP-friendly congestion control to support non-adaptable multimedia flows over the Internet. Existing TCP-friendly congestion control mechanisms assume that flow senders can adjust their sending speeds at a fine granularity to match the requests from the congestion control protocols. In reality, the companion CODEC at the sender guides the source sending rates. To date, the supportable rates of any CODEC are "discrete", not "continuous". Therefore, from the prospective of the transport layer protocols, these data flows are non-adaptable. This renders existing congestion control mechanisms inadequate for real environments. We propose a TCP-friendly congestion control protocol called adaptive multirate transport protocol (AMRTP) to support non-adaptable multimedia flows. We also conduct simulations to evaluate the performance of AMRTP. The results show that AMRTP is TCP friendly, and also has superior performance as compared to existing work.