請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/43921
標題: | 多媒體網路串流的 P2P 及佇列管理技術之探討 A Study on Techniques of Peer-to-Peer and Queue Management for Multimedia Streaming Over the Internet |
作者: | Chin-Fu Ku 顧金福 |
指導教授: | 陳少傑(Sao-Jie Chen) |
關鍵字: | 多媒體串流,同儕網路,佇列管理,網際網路,電腦網路, Multimedia Streaming,Peer-to-Peer Network,Queue Management,Internet,Computer Network, |
出版年 : | 2009 |
學位: | 博士 |
摘要: | 網際網路上的多媒體串流已經慢慢顯現其潛力,然而現今網際網路的設計並未考慮到此應用的需求。本文旨在探討如何提供多媒體串流所需的服務要求,我們從兩個層面切入問題:應用程式層與網路層。選擇此兩層面原因為應用程式層可以提供較大彈性與佈建能力,而網路層則可提供較為精確的控制。應用程式層的探討從最近興起的同儕網路(Peer-to-Peer)及一個檔案分享軟體 BitTorrent 開始,進而提出基於同儕網路的多媒體串流演算法,並以模擬器評估其效能。就模擬結果比較,所提方法能有效提高播放的流暢度。但就實用性而言,一些假設限制仍有其改進的必要性。網路層的探討始於主動佇列管理(Active Queue Management),然而文獻中多從網路效能著眼,而非從使用者端審視其效能。對此我們從文獻與模擬中觀察到其可供增強以改進使用者端效能之處,因而提出一個能加強 TCP 端對端(end-to-end)效能的演算法。從模擬的結果可以看出,所提方法可以有效降低封包延遲(packet delay)、延遲誤差(delay jitter)及封包遺失率(packet loss rate),代價是會稍稍降低整體輸出率(throughput)。 Many and various Internet applications are emerging with rapid development of communication technology and constant increase in user population. Currently, the Internet can only provide a best-effort service which does not fulfill the requirements of many new applications such as multimedia streaming. For this reason, researchers put their effort in studying this problem from many different aspects. In this Dissertation, we study the problem of multimedia streaming over Internet, and approach the problem from two layers—one from the application layer and the other from the network layer. For the application layer, we propose a scheme based on overlay network to meet the requirement of timely transmission by utilizing sampling/pre-fetching technique, as well as utilizing schemes developed by BitTorrent which is a popular peer-to-peer file sharing application. The design increases the exchange probability among participating peers in particular when these peers join at sparse points of time. For the network layer, we propose a queue management scheme for intermediate nodes, such as switches and routers, to improve the quality of communication in terms of end-to-end TCP performance, in particular loss rate, delay, and delay jitter. It takes the change rate of average queue occupancy into account and accordingly adjusts the behavior of handling incoming packets. By monitoring the change rate of averaged queue occupancy, the proposed scheme can early detect significant changes in traffic which may cause congestion. Both schemes are evaluated by simulations and compared with several existing schemes. Compared with a promising scheme previously proposed by Vlavianos et al., our application layer scheme can achieve up to 73% decrease in playback jitter under the condition of an initial latency of 80 seconds. The proposed scheme of queue management gains significant low packet delay, packet drop rate, and delay jitter even under different traffic types and network loads. At the cost of slight decrease in the utilization of links, we believe it can facilitate multimedia streaming over the Internet. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/43921 |
全文授權: | 有償授權 |
顯示於系所單位: | 電機工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-98-1.pdf 目前未授權公開取用 | 1.01 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。