## 1 Introduction
The systems' components are outlined by boundaries and labeled A, B, C, and D. Within boundary A, industrial sensors and applications serve as network endpoints by collecting data and measuring environmental or operational parameters, which are then transmitted to a central platform for analysis. Boundary B represents the private 5G sensor network, which includes 5G radios (RU) mounted on the factory floor's ceiling. These radios function as sensor base stations, converting radio frequency signals into internet packet (IP) signals, which are then relayed to the distributed unit (DU) via access/aggregator switches and gateways. The DU forwards the data to the centralized unit (CU), both of which are components of the 5G radio access network (RAN) deployed on-site in the factory. These units handle radio signal processing and facilitate high-speed, low-latency wireless communication between the sensors and the 5G core (5 GC). The 5 GC manages connectivity, mobility, and session control while also supporting service customization through features like network slicing. Boundary C encompasses edge computing infrastructure, which hosts sensor sink nodes and other Industry 4.0 applications. This setup enables data processing and analysis closer to the sensors, thus reducing latency and offloading computation from centralized cloud servers. Finally, boundary D houses unified industrial automation applications responsible for managing and monitoring Industry 4.0 devices and systems. In existing industrial automation environments, the devices and applications in boundary A and C rely on the OPC UA protocol, a widely adopted standard for industrial system information exchange, to integrate with other applications, such as SCADA, MES, SAP, ERP, and cloud-based manufacturing systems [16]. Meanwhile, the components, like aggregator/access switches, time-sensitive networking (TSN) devices, virtual gateways/routers, 5G radios, CUs, and Dus, expose YANG data models for information exchange, as standardized by the Internet Engineering Task Force (IETF), the 3 rd-Generation PartnershipProject (3 GPP), and Open RAN Working Groups 4 and 10 [17; 18]. Due to the differing semantics of YANG and OPC UA, achieving interoperability between private 5G sensor networks and existing industrial-application management systems that use OPC UA is challenging. This article proposes an interoperability layer, identified in Figure 1 as the \"Mapper\" component, to address these challenges. In the last two decades, several solutions dealing with the interoperability between the OPC UA information model and other protocols/models have appeared in the literature due to the critical role played by OPC UA in Industry 4.0 automation. However, a significant gap in the literature is the lack of existing work that addresses the interoperability of YANG with OPC UA. This research aims to fill the gap by proposing a solution for interoperability between private 5G sensor networks and OPC-UA-based industrial applications. Building on extensive research by [PERSON] on OPC UA interoperability [19; 20; 21], this study proposes a framework for mapping the YANG data models to OPC UA information models. The main aim of this research is to develop a framework to create OPC UA model design XML files from existing YANG models that UA model compilers can utilize to produce OPCA UA NodeSet2 XML files and other language files. Using a rigorous rationale, the authors analyzed the semantics of the YANG and OPC UA elements involved within the scope and established mappings between them. Based on the mapping, the authors proposed the OPC UA pyang plugin to convert the YANG file to an OPC UA model design XML file. pyang is an extensible validator and converter in python that enables developing plugins to convert YANG modules to other formats [22]. The major contribution of this work is that it offers thorough reasoning for the defined mapping through a semantic analysis of the involved elements and the development of a pyang plugin to support interoperability.