近來全球互通微波存取WiMAX 被視為未來的第四代通訊技術，且其高速的傳輸速度及快速的移動能力，被認為可以取代最後ㄧ哩的技術。在本研究當中，我們利用網路模擬工具，在無線對有線的網路環境架構下，分別將網路電話及其他資料傳輸放置在同一個行動台或不同行動台，來評估網路電話的語音品質受到其他資料傳輸的影響程度。在語音模型部分，將採用發話受話之間隔都是遵從指數分配的模型，網路電話的語音編碼技術，我們使用G.729。而在資料模型當中，主要是利用TCP傳送WEB或是FTP封包，UDP傳送MPEG封包。除此之外，無線網路傳輸所產生的封包遺失狀況，則是採用Gilbert Model去模擬此行為。
在本研究中，我們試圖去瞭解不同的資料傳輸模型對網路電話的影響程度，且去分析在兩種不同配置頻寬的方式之間的差異。在語音衡量的指標上，我們採用國際電信組織ITU-T所制定的平均意見分數法（MOS）及E-MODEL。前者是利用透過多位不同的受話測試者聆聽些許聲音片段下，來給予主觀的評分，以用來鑑別網路電話語音品質的好壞。而後者則是透過計算網路電話傳輸語音的過程中若干因素對聲音品質的負面綜合參數，來評估該通話的語音品質。由於在IEEE 802.16e中，其下鏈是採用廣播的方式來傳輸封包，上鏈則是利用分時多工的方式來分配時槽進行資料傳輸，因此上鏈較有研究價值，所以本研究就針對上鏈的語音傳輸做分析。

Recent Worldwide Interoperability for Microwave Access (WiMAX) is viewed as the fourth generation communication technique. Its high speed transmission and fast mobility are thought to be the feasible technology to replace the last mile. In the thesis, we evaluate the quality of speech over a wired-cum-wireless scenario in the present of both voice and different data flows in the same SS or different SSs separately. Voice traffic is modeled by a silence period and a spurt period, both are exponential distributed, and the codec of VoIP is G.729. Data models mainly depend on TCP to transmit WEB or FTP packets, and we use Gilbert Model to simulate the error model for wireless channel.
In this thesis, we want to understand the quality of service in the present of both voice and different data flows, and to analyze different methods of grant bandwidth. In order to measure voice quality, we select mean opinion score (MOS) and E-model recommended by International Telecommunication Union Telecommunication Standardization Sector (ITU-T). In the MOS model, the users who have listened to some sample voice segments give subjective scores for speech quality. Then, the scores are averaged to get the value of MOS. In the E-model, the evaluation of call quality is calculated from some key parameters including several negative factors, such as delay and packet loss. Based on the two evaluation methods, we study the influence of data traffic on quality of VoIP over wireless MAN. In IEEE 802.16e, the packet is transmitted by broadcast in downlink and the packet is transmitted by TDMA in uplink. Because of the uplink is valuable to study, this research focuses on uplink.

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