Within 3GPP, the campus network architecture has evolved as a deployment option for industries and can be provisioned using network slicing over already installed 5G public network infrastructure. In campus networks, the ultra-reliable low latency communication (URLLC) service category is of major interest for applications with strict latency and high-reliability requirements. One way to achieve high reliability in a shared infrastructure is through resource isolation, whereby network slicing can be optimized to adequately reserve computation and transmission capacity. This paper proposes an approach for vertical slicing the radio access network (RAN) to enable the deployment of multiple and isolated campus networks to accommodate URLLC services. To this end, we model RAN function placement as a mixed integer linear programming problem with URLLC-related constraints. We demonstrate that our approach can find optimal solutions in real-world scenarios. Furthermore, unlike existing solutions, our model considers the user traffic flow from a known source node on the network's edge to an unknown \textit{a priori} destination node. This flexibility could be explored in industrial campus networks by allowing dynamic placement of user plane functions (UPFs) to serve the URLLC.

翻译：在3GPP框架内，园区网络架构已发展为面向工业场景的部署选项，并可通过在已部署的5G公共网络基础设施上实施网络切片进行配置。在园区网络中，超可靠低时延通信（URLLC）服务类别对于具有严格时延与高可靠性需求的应用至关重要。在共享基础设施中实现高可靠性的一种途径是通过资源隔离，即优化网络切片以充分预留计算与传输容量。本文提出一种无线接入网（RAN）垂直切片方法，以支持部署多个隔离的园区网络来承载URLLC服务。为此，我们将RAN功能部署建模为带有URLLC相关约束的混合整数线性规划问题。实验证明，该方法能在实际场景中求得最优解。此外，与现有方案不同，本模型考虑了从网络边缘已知源节点至未知先验目标节点的用户业务流。这种灵活性可通过动态部署用户面功能（UPF）来服务URLLC，为工业园区网络提供了新的探索方向。