支援無線實況媒體串流與品質服務最佳化之同儕式平台設計與分析---在同儕式串流平台上之聯合視訊與網路編碼技術

Abstract

在一個具流動性的同儕式(P2P) 實況媒體串流平台架構環境裡，由於有線/無線網路通 道與分流節點隨時間的變遷性，提供服務品質和經驗品質保障的視訊/網路編碼技術具有 相當的挑戰性，也是影音娛樂平台成功的重要關鍵之一。隨著多媒體/通道編碼技術以及 網路通訊的演進，諸如 ITU-T 正在制訂中之網路電視或是YouTube/Joost 之大眾下載隨 選視訊串流已成為近年來無論是學術研究或是工產業矚目之發展重點。本子計畫的主要 目的，在於同儕式媒體串流平台架構的考慮下研發適合之聯合視訊與網路編碼技術 (Joint Video-Network Coding)，在有限通道頻寬的限制下增加有效串流流量，縮減串流 的延遲時間與對抗可能的惡劣傳輸環境，以使隨選視訊或甚至實況網路媒體的品質在日 益普遍之異質有線/無線網路/廣播的傳輸環境下更有保障。在視訊方面，搭配可調式視 訊編碼串流技術，進行相對應結合之網路編碼，讓每個客戶端依據其各自之通訊環境而 接收並分享適合自己環境之多媒體內容服務，在P2P 的 overlay networks 下以網路編碼 的觀點，揉合各自所接收之內容，擴大點對點之間的頻寬傳送率並進行錯誤回復解碼， 以利於使用者對視訊串流時間延遲與影像品質的要求，並可助於縮短頻道切換之間的等 待時間。

In a peer-to-peer live media streaming platform over wired and wireless environments, it is rather challenging to fulfill the needs for Quality of Service and Quality of Experience requirements due to frequent topology updates of P2P overlay network and dynamic channel fluctuation. The required techniques are also the key to the success of such entertainment platforms. Media streaming if entertainment systems, such as IPTV which is being standardized by ITU-T and social networked streaming, like YouTube, have been an emerging research and industrial emphasis due to the great progress of network communications and joint multimedia/channel coding technologies. The major objective of this research project is to study and develop Joint Video-Network Coding technologies in order to increase effective streaming throughput, to minimize the streaming delay, and to mitigate packet loss over heterogeneous networks. The proposed network coding is in particular to be combined with scalable video coding such that every client can download and upload network coded blocks of appropriate streaming contents based on localized channel conditions with the consideration of quality of service and quality of experience, even when a client surfs between video channels.