It is honor to be here to present our work, providing controlled quality assurance in video streaming across the Internet. This is a joint work with Prof. Zhang and Rohit. There has been many video streaming techniques, what makes us different from other is that our work concentrate on the quality assurance issue across best-effort networks, which distinguish our work from all existing approaches.
A video sessions consists of two flows. The P/B frames are sent using a rUDP flow, but the I frames are sent using either a cTCP flow or a TCP flow. In this set of experiments, we compare cTCP/rUDP sessions with TCP/rUDP sessions in the packet losses and retransmission. The x-axis is the number of concurrent sessions, the y-axis is the average number of packet retransmission or packet losses per sessions. Clearly the cTCP/rUDP sessions have much less packet retransmission and losses. This shows the effectiveness of our application-level rate control mechanism.
We run another set of experiments to compare the impact on cTCP/rUDP sessions and TCP/rUDP sessions when new sessions join or exsiting sessions leave. In this set of experiments, the link capacity is set to 5.5 times of the maximum requirement rate of the video, which includes both flows. At the beginning, we have 4 sessions started within 10 minutes; then at segment 10 of the 1 st session, we start the 5 th session; at the segment 13 th of the 1 st sessions, we stop the 3 rd and the 4 th session. The x-axis is the index of segment, and the y-axis is the number of packet loss or retransmission. The top two curves are rUDP packet losses in the 1 st TCP/rUDP session and 1 st cTCP/rUDP session. The bottom two curves are packet retransmission in the 1 st TCP/rUDP session and 1 st cTCP/rUDP session.
Through experiments and simulations, we already show that Our Controlled BW Sharing scheme can protect the essential data, and provide stable system performance. By reducing the blind BW competition, we can significantly reduce the packet transmissions and packet drops. Because our transport protocols show predictable behavior, we can further apply application-ware traffic management schemes.
Providing Controlled Quality Assurance in Video Streaming across the Internet Yingfei Dong, Zhi-Li Zhang and Rohit Rakesh Computer Networking and Multimedia Research Group Dept. of Computer Science and Engineering University of Minnesota