在分空多工彈性光網路上任播需求配置問題

Anycast Routing and Allocation Problem in Space Division Multiplexing Elastic Optical Networks

邱一民(Yi-Min Ciou)

指導教授 ： 丁德榮

國立彰化師範大學/工學院/資訊工程學系/碩士(2019年)

摘要

最近幾年雲端的興起，大量串流媒體使得網路流量越來越大。隨著未來5G的發展，骨幹網路也勢必要承受更大的流量。由於單核芯光纖(single-core fiber，SCF)的傳輸容量在可見的未來會不堪負荷，分空多工 (space division multiplexing，SDM)技術會是未來的解決方案。分空多工技術目前大多以多核芯光纖(multi-core fibers，MCFs)來增進網路傳輸容量。在MCFs中，需求傳送會受到核芯間串擾(inter-core crosstalk，IC-XT)的影響而降低效能。
本論文考慮SDM彈性光網路上，針對路由、調變等級和頻譜配置(routing, modulation level, spectrum assignment，RMLSA)傳輸模式的任播(anycast)傳送問題。在考慮核芯間串擾值上限的限制條件下，任播需求在SDM上的傳送方式，論文中提出以多路徑(multipath)傳送方式來降低阻斷率。另外也考慮任播需求在單一鏈路故障時的保護問題，考慮專屬路徑保護之策略，並提出演算法。
兩種核芯選擇策略，First-Fit (FF)和Random-Fit (RF)，來比較核芯間串擾值的影響。模擬結果顯示，多路徑確實比單路徑有較低阻斷率。在核芯選擇策略方面，阻斷率在低流量的狀況下FF優於 RF，高流量則相反；頻譜使用率整體上FF優於 RF。在任播保護問題，提出的任播專屬路徑保護演算法，相較之前的研究在阻斷率上有明顯改善。

關鍵字

分空多工網路 ； 彈性光網路 ； 串擾 ； 任播 ； 多路徑 ； 保護

並列摘要

In recent years, because of cloud computing, and a large number of streaming media make network traffic growing exponentially. With the development of 5G in the future, the backbone network will have to support larger traffic. Because the capacity of single-core fibers (SCFs) may be not enough in the foreseeable future, space division multiplexing (SDM) may be one of the solutions. Currently, multi-core fibers (MCFs) mostly have been used to enhance the capacity of transmission in SDM. However, the effect of inter-core crosstalk (IC-XT) would reduce transmission efficiency in the MCFs.
In this article, the routing, modulation level, spectrum assignment (RMLSA) problems with anycast traffic in SDM-EON are studied. Multipath routing scheme is used to reduce the blocking ratio of anycast traffic in SDM-EON with the limit of inter-core crosstalk. In addition, the dedicated path protection (DPP) problem for anycast traffic with single-link failure is studied. Two heuristic algorithms for these two problems are proposed.
Two core-assignment methods: First-Fit (FF) and Random-Fit (RF) are used and their performance is evaluated through simulations. The simulation results show that multipath routing method has better than single-path routing method in terms of blocking ratio and spectrum utilization ratio. Moreover, the FF has better than the RF in low traffic load in terms of blocking ratio (BR), and opposite in high traffic load. The FF has better than the RF in terms of spectrum utilization ratio. In anycast protection problem, the proposed algorithm has lower BR than previous works.

並列關鍵字

SDM ； EON ； Crosstalk ； Anycast ； Multipath ； Protection

參考文獻

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