On the Performance of OPC-UA over 5G NPN with Layer 2 Communication

The integration of private fifth-generation (5G) networks with standardized publish-subscribe (PubSub) communication models offers clear benefits for Industry 4.0 applications. While PubSub models ensure vendor-neutral interoperability, backward compatibility, and mature information modeling, the use of 5G non-public networks (NPN) provides dedicated coverage, exclusive capacity, intrinsic controllability, and customized service and operation. In addition, the combination of PubSub protocols and 5G provides a complete communication stack for industrial automation, where PubSub protocols operate on higher OSI layers, and 5G operates on lower layers. However, the practical implications of the integration of PubSub models with 5G systems remain largely unaddressed in the existing literature. To the best of the authors' knowledge, this paper presents the first empirical evaluation of the integration of private 5G with a PubSub protocol, namely open platform communication unified architecture (OPC-UA), in a real production environment. The proposed solution for 5G and OPC-UA integration relies on layer 2 (L2) connectivity over a virtual extensible local area network (VXLAN) tunnel. Evaluation results demonstrate the feasibility of such integration in the context of a soft real-time additive manufacturing (AM) use case for laser metal deposition (LMD)-based manufacturing.