近年來乙太網路(Ethernet)的技術發展克服了速度與距離的瓶頸，使得越來越多的都會及廣域網路服務業者選擇了建置成本較低廉的乙太網路。然而，當位於遠距離兩端的多個乙太網路需要相連接時，現今較經濟的解決方法是結合既有的同步光纖網路(SONET/SDH)，將乙太網路上的封包轉換成同步光纖網路上的固定訊框來傳輸，加上乙太網路的快速成長，電信業者及企業對於Ethernet-over-SONET/SDH (EoS)映射器的需求也與日俱增，映射器的建置不僅僅能提供使用者較為經濟的服務，亦能幫助電信業者透過既有的光纖基礎設施來提供資料服務並增加新類營收。
論文研究重點主要在架構以及通訊協定上針對映射器的設計做多方面的探討與改良，首先透過改變頻寬調整協定(Link Capacity Adjustment Scheme)的表頭，設計新的訊息產生與解譯方式，來加快網路兩端溝通的速度，使得系統對於速率變動極快的乙太網路有較佳的頻寬調節和錯誤反應能力；再者，藉由設計一個包含本地交換(cross-connect)功能的映射器架構，使得LCAS在分配頻寬給多組乙太網路的時候能有保有彈性，不會受到硬體架構的阻礙，而降低頻寬的利用度；此外，我們提出了欄插敘(column-interleaving)的傳送方法，將標準的VC-3 (virtual container-3)傳送單元切成三份來傳輸，透過這個方式來提高多組乙太網路資料的頻寬使用率至97.22%；最後，針對EoS常使用的虛擬連(virtual concatenation)傳輸方式造成的延遲不同問題(differential delay)提出新的映射方法，接收端因而不需要大量的記憶體來緩衝封包各個部分不同抵達時間的缺點，進而降低映射器的成本。
整體而言，此論文所提出的EoS映射器架構具有較高的頻寬使用率，彈性且快速的頻寬分配調整，且針對使用用戶資料訊息協定(UDP)的應用能有不需接收端緩衝記憶體的優點。

Recent development in Ethernet technology drives the deployment of Ethernet from LANs to MANs. However, since Ethernet traffic will eventually be aggregated into SONET in WAN environment, an Ethernet-over-SONET (EoS) mapper designed to ease the transition becomes an important topic for service providers to create new revenues from their legacy SONET infrastructure.
In this thesis, we investigate extensive design issues of an efficient EoS mapper. First, we revise header of link capacity adjustment scheme (LCAS) protocol to accelerate the speed of bandwidth adjustment. Second, we propose architecture with cross-connect functionality to raise flexibility of LCAS bandwidth allocation. Third, we refine virtual concatenation (VCAT) granularity by interleaving payload area of a virtual container-3 (VC-3) in order to further reduce bandwidth waste of transporting multiple groups of client signals. Finally, we devise a new transmission method that doesn’t disassemble an intact packet among diverse routes. Thus, large memory for differential delay compensation can be eliminated in the receiving end for UDP applications.

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