一种基于多路复用的多媒体流TCP友好拥塞控制机制

A Multiplexing-Based TCP-Friendly Congestion Control Mechanism for Multimedia Streaming Applications

本文重点研究在多路复用的链路环境中,TC P友好与多媒体流最低速率阈值限定之间的权衡关系,提出了一种基于多路复用的TC P友好速率控制算法-M TCRC(M u ltip lex ing and thresho ld-con stra ined ra te con tro l).M TCRC引入基于概率的随机试验技术,以保证多媒体流在多路复用时,当友好速率低于限定的最低速率时,通过在适当的时间对部分流的挂起操作,使多媒体流的平均吞吐量仍保持TC P友好.M TCRC是对TFRC(TC P-fr iend lyra te con tro l)的改进,它在保持TFRC良好的速率平滑性的同时,增加了对多媒体流最低速率阈值限定特性及多路复用链路环境的考虑,使其既能尽量保持多媒体流应用的有效性,又能与竞争的TC P流公平地分享带宽.模拟结果显示:M TCRC的性能明显优于TFRC.

This paper focuses on the tradeoff between the TCP-friendliness and the minimum rate threshold of multimedia flows in multiplexing environments, and proposes a multiplexing-based TCP-friendly rate controlling algorithm--MTCRC. It keeps the average throughput of multimedia flows friendly when they are multiplexing and the friendly rate is lower than the restricted minimum rate by hanging up some flows on proper occasion. It also improves TFRC （TCP-friendly rate control） and maintains the favorable rate smoothness of TFRC. Meanwhile the characteristic of the minimum-rate threshold of multimedia flows and multiplexing environments are taken into consideration, so MT- CRC can keep multimedia flows available, share bandwidth fairly with TCP flows. The results of simulating show that MTCRC outperforms TFRC.