IEEE 802.16標準是一種寬頻多媒體網路的標準，此標準可支援五種不同的服務類別並滿足個別QoS(Quality of Service)的需求。
在即時性資料的傳輸中，封包具有時效性，一旦延遲時間超過最大的忍受時間，封包便會被丟棄。我們將針對WiMAX網路中的real-time traffic，如ertPS，設定它在佇列中delay time的限制值，當封包在佇列的時間超過此限制值時，將被丟棄。接著以考慮佇列長度的頻寬分配法，來模擬各種負載下的封包遺失率。在佇列長度的頻寬分配法(BA-QL2)中，各個等級的資料有一個權重值β，在本論文中首先模擬出，當ertPS在不同的β值時，負載與封包遺失率的關係，並畫出性能評估圖。如此，在某種負載情況下，根據我們所需要的封包遺失率，透過我們所提出的演算法，可以找出所需要的β值，使得模擬出的封包遺失率與系統所需要的遺失率的誤差在系統可接受的範圍內。以此β值來執行考慮佇列長度的頻寬分配法，可讓系統在此一負載下，達到所需要的封包遺失率。
本論文的目的在於提出一個可供執行的參考方案，讓系統管理者可依據系統的環境與需求，去找到精確的β值。

IEEE 802.16 is a broadband multimedia standard which supports five different service classes and satisfies QoS(Quality of Service) requirements for each class.
The real-time packets are constrained by timing. When the delay time of transmission is bigger than the maximum value, packets will be dropped. In this dissertation, we focus on the ertPStraffic in WiMAX network and set a constraint on its delay time.With thisconstraint, packet dropping happens when delay time of a packet is bigger than this value.Then, the bandwidth is scheduled according to the length of each queue.With simulation, packet loss ratesare found for different traffic loads.With the second method of bandwidth allocation according to queue length(BA-QL2), each class is assigned a weight β. The main purpose of this dissertationis to find this value for possible required loss rate. With our proposed algorithm, β can be found such that the loss rate can be as close to this required value as possible. In this dissertation, the proposed algorithm is simulated and tested. The simulated approach can be used as a templatefor anyone who wants to find an appropriate β for his model.

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