Network slicing (NS) is recognized as a key technology for the 5G mobile network in enabling the network to support multiple diversified vertical markets over a shared physical infrastructure with efficiency and flexibility. A 5G NS instance is composed of a set of virtual network function (VNF) instances to form the end-to-end (E2E) virtual network for the slice to operate independently. The deployment of a NS is a typical virtual network embedding (VNE) problem. We consider a scenario in which VNF instances can be shared across multiple slices to further enhance the utilization ratio of the underlying physical resources. For NSs with sharable VNF instances, the deployment of the slice instances is essentially the embedding of multiple virtual networks coupled by the VNFs shared among slices. Hence, we formulate this sharable-VNFs-based multiple coupled VNE problem (SVM-VNE) through an integer linear program (ILP) formulation, and design a back-tracking coordinated virtual network mapping algorithm. Simulation results demonstrate that VNF-sharing can enhance the slice acceptance ratio with the same physical network, which represents higher physical resource utilization. Moreover, our approach achieves higher acceptance ratio by comparing to a baseline algorithm.

中文翻译：

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嵌入可共享虚拟网络功能的 5G 网络切片

网络切片 (NS) 被认为是 5G 移动网络的一项关键技术，它使网络能够高效灵活地支持共享物理基础设施上的多个多元化垂直市场。一个5G NS实例由一组虚拟网络功能（VNF）实例组成，构成切片独立运行的端到端（E2E）虚拟网络。NS 的部署是一个典型的虚拟网络嵌入 (VNE) 问题。我们考虑一个场景，其中 VNF 实例可以跨多个切片共享，以进一步提高底层物理资源的利用率。对于具有可共享 VNF 实例的 NS，切片实例的部署本质上是嵌入多个由切片之间共享的 VNF 耦合的虚拟网络。因此，我们通过整数线性规划 (ILP) 公式制定了这个基于可共享 VNF 的多耦合 VNE 问题 (SVM-VNE)，并设计了一种回溯协调虚拟网络映射算法。仿真结果表明，VNF-sharing可以在相同物理网络的情况下提高切片接受率，代表更高的物理资源利用率。此外，通过与基线算法相比，我们的方法实现了更高的接受率。