Abstract
整體服務數位網路﹝Integrated Services Digital Network，ISDN﹞是 以數位傳送方式及數位交換方式運作的網路，它以整合性的方式提供各種 不同通訊業務。國際電報電話諮詢委員會在1984年明確提出了有關整體服 務數位網路的標準﹝I-系列建議﹞，讓電信製造業者在發展相關的整體服 務數位網路產品時有一致的規範，同時也使得使用者只需利用少數種界面 接至網路就可以進行多種通訊並獲得多樣的服務。雖然整體服務數位網路 的目標是以單一的數位網路整合各種不同通訊業務，但它已無法滿足隨著 通訊業務往多元化及高質量化發展後所帶來的寬頻要求。於是又有寬頻整 體服務數位網路﹝Broadband Integrated Services Digital Network， B-ISDN﹞的提出。國際電報電話諮詢委員會在1988年明確訂定非同步傳輸 技術﹝Asynchronous Transfer Mode， ATM﹞為製作寬頻整體服務數位網 路的基本方式。非同步傳輸技術繼承了高速電路交換方式和高速封包交換 方式的優點。非同步傳輸技術的核心是交換系統﹝switching system﹞， 它的基本功能是將所收到的訊息單元﹝cell﹞送到目的地。在非同步傳輸 技術網路中，單元是以毫無規律的方式進入交換系統，這種無規律的方式 使得各單元在交換的過程中面臨資源﹝如暫存記憶體及中間傳輸線﹞的競 爭問題，若沒有一個完備的交換架構與控制方法，這些資源的競爭問題將 導致高單元遺失率及增加交換的延遲時間，不但使得整個網路系統的效益 下降，更進而影響通信業務的品質。如何為非同步傳輸技術網路架構一高 效益的交換系統實為當前的一大課題。在本論文中，我們提出若干種滿足 非同步傳輸技術網路要求的交換系統。這些交換系統的架構、控制方法、 及成本複雜度皆有完整詳細的描述。我們也提出一正規的計算模式來評估 所提交換系統的執行效益。 The significant improvement of fiber optics and microcomputer technologies in the last decade has stimulated multimedia and other applications that require very great bandwidth and integrated transport from the communication networks. This has motivated the explosive growth in interest in Broadband Integrated Service Digital Network (B-ISDN). The B-ISDN offers versatile communication services such as voice, data, image and video, and is expected to be incorporated into the future social infrastructure. The heterogeneity in the requirements of these different services requires revolutionary innovation in switching technologies. The Asynchronous Transfer Mode (ATM) switching system concept is considered the target transfer mode solution for implementing a B-ISDN. Switching in ATM based B- ISDN has been the subject of vigorous research over the past several years. The design of a high-performance ATM switch is considered as a fundamental challenge for the success of B- ISDN. In the Dissertation, several high-performance ATM switching systems are proposed for B-ISDN. According to the design consideration, the proposed switches may be classified into three categories: (1) multi-plane fabrics, and (2) baseline-tree fabrics, and (3) fabrics capable of multicast. To appraise the switch performance more precise and realistic, we develop a more general analytical model that can evaluate the performance of any switching system under any traffic pattern. The developed analytical model has been applied to our proposed switches to demonstrate their high performance and robustness under more general conditions. The numerical results of the analytical model have also been validated by means of computer simulations.