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標題: | 隨按即說服務之音質分析 The Speech Quality Analysis of Push-to-Talk Services |
作者: | Kun-Yi Tsai 蔡坤益 |
指導教授: | 郭大維(Tei-Wei Kuo) |
關鍵字: | 隨按即說,服務,聲音品質,網路,電話,封包延遲,延遲差異,封包遺失, Push-to-Talk,Speech Quality,MOS,Jitter,VoIP, |
出版年 : | 2008 |
學位: | 碩士 |
摘要: | 隨著網際網路電話(Voice over Internet Protocol)應用的蓬勃發展,近幾年,隨按即說(Push-to-Talk,PTT)的服務逐漸受到重視。不同於電話原本全雙工的通訊模式,PTT 相似於傳統的無線對講機(Walkie Talkie)提供一個半雙工服務;同一時間只允許一個使用者發話,群組中其餘成員只能聆聽。這篇論文針對PTT 之音訊品質做一系列探討,以目前最普遍使用的MOS (Mean Opinion Score) 作為聲音品質評估方法,我們重新分析聲音品質的因素,並經由實驗的方式進一步找出其與系統設計相對應的關係。在實務上,我們針對封包延遲、延遲差異與封包遺失等現象進行分析,並思考系統設計與提升聲音品質的相關對策。我們並從系統設計的角度與網路架構的規劃上,探索提升整體服務的語音品質與系統的性能。 With the popularity of VoIP, Push-To-Talk (PTT) services over the IP networks have gained their momentum. This research aims at essential design issues for speech quality of PTT services. We explore the relationship between speech quality and system design issues. MOS (Mean Opinion Score), which is raised by the ITU-T International Telecommunication Union) as one of the most common benchmarks, is studied under factors in system designs and implementations. In particular, we focus on the analysis of packet delay, jitter, and packet loss for PTT services. Experiments are designed and executed with the considerations of PTT characteristics. Our goal is to provide more understanding of MOS versus PTT and deliver insights in future PTT system designs. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/27126 |
全文授權: | 有償授權 |
顯示於系所單位: | 資訊工程學系 |
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