隨著網路頻寬的不斷提升，影音串流視訊傳輸也受到越來越多重視。在這一篇論文裡面，我們提出了以代理伺服器來為基礎的串流視訊傳輸架構。這個架構包含了在骨幹網路以及區域網路上的多媒體檔案伺服器、代理伺服器(Proxy)、與客戶端設備。當客戶端向代理伺服器發出多媒體檔案的要求時，多媒體檔案伺服器即傳輸據多層漸進式(Scalable)特性的檔案到代理伺服器端。代理伺服器則根據網路狀況及網路頻寬傳送最適合的品質給客戶端。
為了讓整個系統的效率更為提升，在這篇論文內也提出了三個重要的方法：漸進式防錯與交錯式資料封包、位元率平滑化，以及原始資料與錯誤控制的調整機制。透過這些方法，客戶端可以克服網路的限制得到較高品質的多媒體檔案。

A proxy-based streaming video distribution framework is proposed in this thesis. This framework consists of content server, edge server (proxy), client device along with the backbone and access network. Content server delivers a scalable video bitstream to the proxies where the requests were issued. Each proxy maintains the traffic information including the packet loss rate and the available bandwidth of its own access network to accommodate the scalable stream passed through it.
Three new methods were invented to support this delivery framework to promote the system efficiency: they are interleaving packetization with UEP (Unequal Error Protection), bitrate smoothing, and regulation mechanism. The interleaving packetization with UEP gives graceful quality degradation, which is adaptive to the bandwidth variation and loss rate change during transmission. Bitrate smoothing makes use of buffering and startup delay to smooth out the output bandwidth constantly. Finally, given the traffic condition (available bandwidth and loss rate), the regulation mechanism uses the dropping and re-coding to regulate the scalable bitstream between the backbone and its own access network.

[1] D. Wu, Y. T. Hou, W. W. Zhu, Y.-Q. Zhang, and J.M. Peha, “Streaming Video over the Internet: Approaches and Directions,” IEEE Transactions on Circuits and Systems for Video Technology, VOL. 11, Mar. 2001, pp. 282–300.
[2] D. Wu, Y. T. Hou, and Y.-Q. Zhang, “Transporting Real-time Video over the Internet: Challenges and Approaches,” Proceeding of the IEEE, VOL. 88, Dec. 2000, pp. 1855–1877.
[3] W. Li, “Overview of Fine Granularity Scalability in MPEG-4 Video Standard,” IEEE Transactions on Circuits and Systems for Video Technology, VOL. 11, Mar. 2001, pp. 301–317.
[4] F. Wu, S. Li, and Y. Zhang, “A Framework for Efficient Fine Granularity Scalable Video Coding,” IEEE Transactions on Circuits and System for Video Technology, VOL. 11, Mar. 2001, pp. 332–344.
[5] R. Kalluri, “Single-Loop Motion-Compensated based Fine-Granular Scalability (MC-FGS)”, MPEG2001/M6831, Jul. 2001.
[6] X. Zhang, A. Vetro, Y. Shi, and H. Sun, “Constant Quality Constrained Rate Allocation for FGS Video Coded Bitstreams,” Proceedings of SPIE Conference on Visual Communications and Image Processing (VCIP) 2002, VOL. 4671, pp. 817–827.
[7] Y. Wang and Q. Zhu, “Error Control and Concealment for Video Communication: A Review,” Proceedings of the IEEE, VOL. 86, May 1998, pp.974–997.