When circuits are set up and dismantled dynamically in elastic optical networks, spectrum tends to become fragmented in the fiber links. The fragmentation limits the available path choices and may lead to significant blocking of connection requests. There are two types of fragmentation in the network spectrum in the links due to contiguity constraints and over the paths due to continuity. Study of fragmentation and its management is essential to operate the networks efficiently. This paper proposes a vectored fragmentation metric for characterizing the fragmentation, which covers both types of fragmentation. We discuss the characteristics of this metric in both transient and steady-state of the dynamic network. We also test the proposed metric for connection requests granularity range, arrival rates and holding times, to establish functionality of this metric. We also compare the link-based fragmentation metric with our Vectored Fragmentation Metric to understand the better representation.

中文翻译：

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弹性光网络的矢量碎片度量

当在弹性光网络中动态建立和拆除电路时，频谱趋于在光纤链路中破碎。碎片限制了可用的路径选择，并可能导致严重阻塞连接请求。由于连续性限制，链路中的网络频谱存在两种类型的碎片；由于连续性，路径中存在两种类型的碎片。对碎片及其管理的研究对于有效运营网络至关重要。本文提出了一种用于表征碎片的矢量化碎片度量，其中涵盖了两种类型的碎片。我们讨论了该指标在动态网络的瞬态和稳态下的特征。我们还针对连接请求的粒度范围，到达率和保持时间测试了建议的指标，建立该指标的功能。我们还将基于链接的碎片度量与我们的矢量碎片度量进行比较，以了解更好的表示形式。