全光都會網狀/環狀骨幹及其互聯之光纖及無線擷取網路整合技術---子計畫一：全光分波多工具服務品質能力之都會環狀網路技術

Abstract

隨著網際網路頻寬需求的日漸成長與optical Wavelength Division Multiplexing (WDM)領域上的進 展，下一世代網路的設計與實現有了本質上的改變。光纖長途網際網路架構雖已能解決目前的訊務需 求且能滿足目前的頻寬成長趨勢，但仍有兩個重要的瓶頸仍存在於網路鏈上。首先是最後一哩(last mile) 或稱為擷取網路之問題，即探討如何提供適合的頻寬給使用者。另一個瓶頸是介於光纖網際網路與擷 取網路之間的都會型核心(Metro Core)網路或被稱之為都會骨幹網路的問題。長途的光纖網際網路通常 是建置在網狀拓樸中，以固定的WDM 頻道效能使用光電路交換(OCS)技術與光群聚交換(OBS)技術， 而光纖都會型核心網路則可採用網狀拓樸、環狀拓樸及排狀拓樸的網路架構。這個計畫我們將著重於 環狀都會骨幹網路之技術與實驗。 不同於長途骨幹網路，都會骨幹網路需面對較高的動態訊務需求，因此使用固定的WDM 頻道將 不可行。光纖都會環狀網路需要全光封包交換(OPS)技術，並配合每個節點之多功能媒體存取控制 (MAC)機制，來提供有效率的頻寬分配與不同等級的網路服務品質(QoS)保證技術。在這三年期計畫 中，我們的主要目標是對全光WDM 服務品質都會環狀網路進行設計、分析及建構研究平台。這三年 中將進行的工作整理於下圖的時程表中。基本上，在計畫的第一年中，我們將進行深入的文獻研讀及 初步的系統架構設計；第二年我們將對光傳輸系統進行主要的設計與分析工作；在第三年將著手進行 服務品質需求的議題。實驗平台建置會在第一年期中過後開始執行，預計在計畫結束前完成。

The ever-growing demand for Internet bandwidth and recent advances in optical Wavelength Division Multiplexing (WDM) technologies brings about fundamental changes in the design and implementation of the next generation networks. Even though the optical long-haul Internet has been designed to foster the current traffic demand and bandwidth growth trend, two critical bottlenecks are still present in network chains. The first one is the so-called last mile, or access networks, which provide bandwidth directly to end-users. The other one that behaves as transitional bandwidth distributors between the optical Internet and access networks is the core of Metropolitan Area Networks (MANs), referred to as metro core or backbone network. Long-haul optical Internet is based on a mesh topology, and follows the Optical Circuit Switching (OCS), or Optical Burst Switching (OBS) paradigm by making relatively static WDM channel utilization. As opposed to it, optical metro core networks are based on mesh, ring, or bus topologies. In this project, we focus on the technology and experimentation of a ring-based metro backbone network. Metro backbone networks, unlike long-haul backbone networks, exhibit higher dynamic traffic demand, rendering static WDM channel utilization completely infeasible. As a result, optical metro ring networks require the Optical Packet Switching (OPS) technique augmented with versatile Medium Access Control (MAC) scheme at each node to assure efficient bandwidth allocation and various Quality-of-Service (QoS) guarantees. In this three-year project, our main objectives are the design, analyses, and testbed construction of such optical WDM QoS-Enabled metro ring network. In summary, the tasks to be accomplished in these three years are depicted in the following roadmap. In principle, we give the decent study and preliminary design in the first year. While we perform the major design and analyses for the basic transport in the second year, we tackle the QoS satisfaction issue in the last year. The testbed construction will be carried out from the last quarter of the first year till the end of the project.