國立臺灣大學電信工程學研究所吳靜雄2006-07-262018-07-052006-07-262018-07-052003-07-31http://ntur.lib.ntu.edu.tw//handle/246246/20260隨著網際網路流量的成長，對網路容量的需求也迅速增加。以往電的封包交 換技術在處理巨大流量時面臨了瓶頸。利用光封包交換技術(OPS)以及分波多工 技術(WDM)，可以提供高速交換能力以及資料的透明度，是個可行的解決之道。 在光交換技術上，只有一些簡單的優先策略(Priority Strategy)才可以被應用。但 是目前被提出的技術大多適用於短程相關的流量上。實際上的網路流量應該是有 自我相似特性的流量。這種長程相關的流量(LRD)若不加以討論會使網路的效能 嚴重下降。在本計畫中我們提出了幾個簡單優先策略的效能分析，並且試著提出 最好的優先策略。 另外，被動光網路(PON)被視為可以真正實現全服務接取網路(FSAN)的方 法。現在提出的被動光接取網路以時域多工(TDMA)與非同步傳輸模式(ATM)為 主，然而對於網際網路或乙太網路封包而言，時域多工並不適用；為了實現真正 寬頻接取服務，必需解決寬頻接取網路的問題；本計劃提出一個以光分碼多工應 用在被動光網路之實驗網路，此系統可以真正達到寬頻接取的服務。在本計畫中 並且設計一個同步電路，分析結果顯示此同步電路可以有效降低時間偏差對系統 的影響。With the explosive growth of Internet traffic, demands for network capacity expand rapidly. Electrical packet switches have faced the limits in handling tremendous traffic. Optical packet switch (OPS) incorporating with wavelength division multiplexing (WDM) technology, which has high-speed switching capability and data rate/format transparency, seems to be an alternative in the near future. Only the simplest mechanisms, such as passive schemes, are promising to perform the functions for OPS. Some simple priority strategies for OPS have been reported in the literatures [1]-[3]. However, those proposed approaches are only discussed under short-range dependent traffic. Real Internet traffic has shown the self-similar nature, which can cause serious performance degradation [4]. The influence of long-range dependent (LRD) traffic on buffer management should be investigated. This paper presents the performance analysis of several simple priority strategies under LRD traffic and recommends the most efficient priority strategy. On the other hand, Passive optical network (PON) is considered to be a solution to realize full-service access networks (FSAN). It is a point-to- multipoint optical network with no active devices through the signal transmission. Combining Ethernet frame with PON (EPON) is a promising candidate for next-generation broadband access networks. We proposed an EPON configuration using optical code division multiple access (OCDMA) in its upstream direction. We also propose a synchronization circuit to eliminate the effect of jitter. Numerical results show that the proposed synchronization circuit can make the system robust against jitter. The proposed system can achieve the goal of future broadband access networks.application/pdf362904 bytesapplication/pdfzh-TW國立臺灣大學電信工程學研究所reporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/20260/1/912213E002106.pdf