UTFRC - Utility-driven TCP-Friendly Rate Control for Multimedia Streams

This paper describes UTFRC- Utility-driven TCP-Friendly Rate Control, a congestion control mechanism more suitable for streaming layered scalable video streams in best-effort networks than TFRC [2]. UTFRC relies on the original TFRC for achieving a stable throughput, but uses the throughput outputted by TFRC only as a guideline and shapes this throughput, on a coarser granularity scale, according to media characteristics of the video stream. This way, UTFRC is TCP-friendly when computing avail-able bandwidth, but it is also media-sensitive (i.e., media-friendly). We present two versions of UTFRC, a simple one based only on bitrate properties of the video stream and an advanced one which takes into account also the client prefetching buffer value, but other media characteristics of the stream can also be considered. UTFRC improves the perceived quality of video streams in best-effort network conditions. 1