隨著網際網路對於頻寬需求的快速成長，使用光波分割多工的光纖網路，成做為下一世代網際網路骨幹的首選。光波巨量資料單位交換是一個在光波分割多工網路上能有效利用頻寬的交換技術。另外，及時規約是光波巨量資料單位交換上最為人所知的一種信令協定，它能有效的利用網路頻寬並且減少端對端傳送延遲。但是即時規約也有著先天的缺陷－公平問題，公平問題不僅會造成彷彿偏好較短傳輸距離的巨量資料之現象，也會導致網路利用率的下降。本篇論文中，我們將仔細的研究公平問題，並且提出一個名為公平優先權競爭的通道排程演算法作為解決方案。

　　公平問題是一個已存在於各種網路上的問題。一般而言，通常要改善公平問題，需要權衡對其他網路效能所造成的影響，因此我們的演算法把主要的焦點放在如何做到兩者兼顧並取得平衡。公平優先權競爭演算法根據巨量資料單位的已走過節點個數、剩餘節點個數等，賦予每個巨量資料單位一動態優先權值，當兩個巨量資料單位發生碰撞，公平優先權競爭演算法即比較兩者的優先權值，並決定何者可取得預約權。由模擬程式而得的結果顯示，我們的演算法在解決公平問題的同時，並沒有使巨量資料單位的傳輸失敗率增加，甚至還能提升有效網路利用率。

　With the explosive growth of Internet traffic demands, optical networks based on wavelength division multiplexing (WDM) is a promising solution to the next generation backbone technique. In order to realize IP-over-WDM, an efficient switching technique named Optical burst switching (OBS) has been proposed. Among various signaling protocols designed for OBS networks, the most popular signaling protocol on OBS is Just-Enough-Time (JET) protocol. JET can utilize the network capacity efficiently and reduce end-to-end transmission delay. However, it suffers an innate defect – the fairness problem. The fairness problem not only results in a phenomenon as if bursts with shorter hops were favored but also deteriorates the networks utilization. In this thesis, we investigate the problem and propose a fair channel scheduling algorithm named Fair Prioritized Preemption (FPP) as a solution.
Fairness problem which is a traditional problem existing on various kinds of networks. Generally speaking, it is usually a trade off between fairness and performance. Our proposed algorithm tries to consider both of them and keep balanced. FPP gives each burst a dynamic priority which is defined by its experienced hop counts, remaining hop counts, etc. When a contention occurs, FPP selects the preferable burst and drop another one. The simulation results show that FPP can improve fairness without sacrificing dropping performance. In addition, it increases the effective link utilizations as well.

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