A Unicast Rate-Based Protocol for Video Streaming Applications over the Internet

This paper presents a unicast rate-based transport protocol that regulates transmission rate for video streaming over best-effort networks such as the Internet. The protocol runs on top of the Real-time Transport Protocol and relies on the feedbacks reports of its sister protocol Real-time Transport Control Protocol to control congestion. The proposed protocol uses the square increase multiplicative decrease rules to alter its transmission rate and operates in a TCP-friendly way towards TCP flows. In addition, the protocol includes two control criteria: the cumulative jitter and the delay factor to allow incipient congestion detection prior to loss of video packets. With the addition of these criteria, the transmission rate is adjusted in a way that anticipates loss of video packets. Network parameters such as packet loss ratio and Round-Trip Time as well as the TCP-friendly shared throughput are computed at the receiver, and the results sent back to the sender using in the receiver packet report. Upon reception of the feedback information, the sender adjusts the sending rate to match the network's available capacity. The performance evaluation results using both network related metrics and video quality measurement show a performance improvement in terms of frame loss rate and peak signal to noise ratio, providing the receiver with an image of better visual quality than the classical TCP-Friendly Rate Control (TFRC) protocol.