在本論文中，針對在差異性服務網路架構下支援網路回饋機制的多媒體傳輸，我們提出了一套可調適性的策略將封包平滑的標記成具有較高等級的服務品質。此項機制主要考量在使用者付費的基礎下如何讓網路資源的利用更有效率。相對於將整個要求較佳服務等級的資料流從始至終皆優先傳送，我們只需要在網路擁塞的時段依據使用者預期的服務品質將一部分的資料量標記成優先傳送。為了提供穩定的多媒體感官效果，所提出的這項策略採用了平滑式的標記方法，除了儘可能的保證封包遺失率外同時也可以分散掉連續性封包遺失的效應。相關的系統實作已在採取即時協定發展的固定位元速率(Constant bit rate)語音以及可變位元速率(Variable bit rate)影像服務之特定應用程式上完成並加以驗證。最後，本篇論文也陳列出在實際的測試平台中所得到的效能及其評估結果。

In this paper, we present an adaptive smooth strategy to mark packets of multimedia stream supporting network feedback mechanism over Differentiated Service networks. This paper focuses on the basis of usage charging and of network resources utilization. In contrast of transmitting all packets at the premium class, only a portion of the packets is marked as premium to meet users’ expectation when the network is congested. To provide steady perceptual quality, the proposed strategy adopts the smooth marking scheme which scatters the possible continual packet loss to conform the soft loss rate guarantees. The implementations are made for the CBR and VBR traffic including audio and video stream respectively based on real-time protocol (RTP) standard. Finally, the performance results evaluated in the physical testbed will be given.

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