WiMAX 是一種新興起的無線通訊網路，它提供高速網路存取與多媒體服務，
可以支援多種不同類型的QoS(Quality of Service)，為此在WiMAX 中，能夠有效
地做到頻寬的分配就非常重要。在有限的頻寬中，要確保即時性資料的吞吐量與
延遲時間。而在IEEE 802.16 標準中並沒有將頻寬分配的方法詳加規定，留給了
網路通訊設備商自行設計。如何達到最有效的資源分配的方法，可以加以探討。
本篇論文將會提出會依據連線負載調整的頻寬分配法。每條連線在第一回合
都可以獲得固定頻寬，在第二回合我們將會提出兩種權重的計算方式，第一種為
依據第一回合後連線的剩餘佇列長度，做為每條連線的權重。第二種依據第一回
合後連線的剩餘佇列長度及優先權，做為每條連線的權重。之後根據連線權重比
例，將第一回合分配後剩餘的頻寬分配，直到佇列長度歸零或是頻寬用盡。 我
們將模擬這兩種方法並與Round Robin 方法做比較，結果顯現我們所提出的兩種
方法，可以依據連線負載分配頻寬。

Worldwide Interoperability for Microwave Access (WiMAX) is a broadband
wireless access (BWA) technology. It provides high data rate and multimedia service.
WiMAX support Quality of Service (QoS) for various types of application. It is
important to allocate appropriate resource to different class of service to guarantee the
delay of real-time service and avoid the starvation of non-real-time service. In IEEE
802.16 standard for WiMAX network, this part is left opened to be explored.
The connection admission control (CAC) mechanism allows a connection to
reserve a bandwidth beforehand. Since a good prediction of the needed bandwidth is
not easy, a reserved bandwidth may not always be equal to the needed one.
Therefore, an algorithm adaptive to the load is proposed in this paper. A fixed
bandwidth is assigned to each connection in the first round according to the reserved
bandwidth. In the second round, two weight round robin algorithms are proposed.
In the first one, the weight is decided by the left queue length of the connection. In
the second one, the weight is decided by the left queue length and priority of the
connection. The second round will continue until the bandwidth of the frame is
exhausted or all packets in the queue have been scheduled. The simulation has been
done for theses two algorithms and compared with round robin algorithm. The result
shows these algorithms can adapt to the load of the connection for a fixed reserved
bandwidth.

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