（北方工业大学信息工程学院，北京市，100041）
摘要：在基于3G网络的多媒体调度系统中，为了提高视频数据传输的实时性和可靠性，提出一种视频流码率自适应调整算法。通过改进Pathload 算法，利用视频数据包的单向延时来估计网络有效带宽，根据网络有效带宽与视频发送速率之间的大小关系自适应地调整视频流码率。在多媒体调度系统上进行了实验验证，结果表明，该算法可以比较准确地估计网络有效带宽，有效地改善了视频数据传输的实时性并提高了接收端的视频数据解码质量。
关键词：信号与信息处理；调度系统；自适应编码；网络带宽估计
An Algorithm of Video Stream Rate Adaptive Control
PENG Kai
(Information Engineering Institute of North China University of Technology, Beijing, 100144, China)
【Abstract】In multimedia scheduling system based on 3G networks, In order to improve the timeliness and reliability of video data transmission, Propose an algorithm of video stream rate adaptive control. Estimate the effective bandwidth of the network by one-way delay of video p -ackets, Adaptive control the video stream rate by compare effective bandwidth of network and video transmission rate. Experiment on multimedia scheduling system, Results show the algorithm could estimate effective bandwidth of network accurately, Improve the real-time of video data tra- nsmission effectively and Improve the quality of Decoded video data.
【Key words】Signal and Information Processing; Scheduling system; Adaptive coding; Estimate the bandwidth of network

5参考文献
[1] WANG ZHENGJUN, WANG YOUZHAO. Strategy of closed—loop rate control and traffic shaping based on RTCP[J]. Computer Science, 2011, 8(7): 100—102.
[2] YU SU, SHENG YANJAN, HUANG KAI, et al. Research on the algorithm of RTP adaptive transmission control[J], Computer Engineering & Science, 2005, 27(11): 52—56.
[3] JAIN M,DOVROLIS C. End to end available band width: measurement methodology, dynamics, and relation with TCP through put. IEEE/ACM Transactions on Networking, 2003, 11(4): 537–549.
[4] STRAUSS J, KATABI D, KAASHOEK F. A Measurement Study of Available Bandwidth Estimation Tools, In: Proc of Internet Measurement Conference. Miami, 2003, 39-44.
[5] 蔡山，张浩，陈洪辉．基于最小二乘法的分段三次曲线拟合方法研究[J]. 科学技术与工程，2007.
CAI SHAN, ZHANG HAO, CHEN HONGHUI. Research on piecewise cubic curve fitting method based on Least Squares[J]. Science Technology and Engineering,2007.
[6] JAIN M, DOVROLIS C. Pathload: A measurement tool for end-to-end available bandwidth, In: Proc of Passive and Active Measurements Workshop, Fort Collins, 2002.
[7] TOS URAS, AYAV TOLGA. Adaptive RTP rate control method[C] Computer   Software and Applications Conference Workshops. Mumch, Germany, 2011.
[8] LAKSHMINARA YANAN K. Bandwidth estimation in broadband access networks[D]. Berkeley ; University of California,2004.

作者简介：
彭锴（1990.1.13），男，硕士，视频编码与传输