IEEE 802.16j標準沿用IEEE 802.16e的網路系統，在不改變現有用戶端(Subscriber Station; SS)設備的前提之下，加入了中繼站(Relay Station; RS)來協助用戶端轉送資料給基地台(Base Station; BS)。IEEE 802.16j標準當中定義了兩種類型的中繼站，分別是穿透式中繼站(Transparent Relay Station)以及非穿透式中繼站(Non-Transparent Relay Station)。然而，標準中只定義固定式的訊框架構，訊框架構中的區間(Zone)是以固定大小的方式進行切割，無法進行動態調整。在實際應用上，網路中的負載會隨著時間而變動，此種固定式訊框架構在網路負載發生變化時，系統無法即時依照負載變動的行為，對訊框架構做最佳化的調整，將導致用戶端的服務品質下降。
為了解決上述問題，本論文提出了適應性調整(Adaptive Adjustments; AA)訊框架構，取代原本的固定式訊框架構。訊框中採用適應性調整的方式，讓區間比例可以依照網路負載的變動而即時調整，以確保系統資源更有效的被使用，訊框架構也更可以滿足用戶端的需求。我們將所提出的方法與標準之固定式訊框架構做比較。從模擬結果可知，在各效能評估項目上，本論文提出的適應性調整訊框架構會有更好的網路產能及更低的傳輸延遲。

IEEE 802.16j standard follows the network architecture of IEEE 802.16e, without changing the existing subscriber station (SS) equipments. It uses relay station (RS) to forward messages between base station (BS) and subscriber stations. IEEE 802.16j standard defined two different types of relay stations, one is transparent relay station, and another is non-transparent relay station. However, the standard only defined a fixed frame structure. The size of each zone is based on a fixed percentage in a frame. IEEE 802.16j standard does not define the adaptable frame structure, which means the percentage of each zone can adjust dynamically. In fact, the network load changes over times. In fixed frame structure, the system cannot optimize the frame immediately when network load is changing; resulting decline in the quality of service of subscriber stations.
In order to solve the above-mentioned problems, we proposed a frame structure with adaptive adjustments (AA) mechanism to replace the original fixed frame structure. By using adaptable frame structure, the size of each zone is decided by network load. It can use system resources more effectively; the frame structure can also satisfy the needs of subscriber stations. We compare our scheme and the IEEE 802.16j standard. From the simulation results, our adaptable scheme will improves the network throughput, and also reduce transmission delay. In short, our adaptable frame structure can achieve better network performance.

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