# An Experimental Framework for 5G Wireless System Integration into Industry 4.0 Applications
## 1 Introduction  
Seamless system integration is a key aspect of the fourth industrial revolution (Industry 4.0) [1]. In this respect, 5G, one of the most advanced connectivity options, designed to achieve low latency, high reliability, flexibility, and security [2], is expected to be integrated with different cyber-physical systems (CPS), other industrial Internet-of-Things (IIoT) technologies, and cloud computing. This will bring smart factories and other industrial production environments to the next level in terms of optimization of the production processes and flexibility and re-configuration of the industrial manufacturing systems [3]. Common for most of these concepts is that they require extensive knowledge of information technologies (IT) and operational technologies (OT). Furthermore, as such, they should be viewed as a multi-disciplinary venture, making the transition to 14.0 for a particular company, site or factory not an easy task. To assist in this transition, multiple frameworks/methodologies have been proposed, mainly with the aim of defining roadmaps based on the digitalization and technological readiness levels [4, 5, 6, 7]. These frameworks aim mainly at helping industrial manufacturing companies in identifying their levels of digital maturity, as well as guiding their digitalization efforts withthe addition of reflective steps throughout the entire process. In general, these frameworks emphasize that reliable wireless connectivity is the key enabler for system interconnection, allowing for tying all the factory assets together in a seamless way, and facilitating the deployment of advanced IT concepts such as big data and artificial intelligence (AI) but also OT concepts such as autonomous mobile robots or matrix production [7]. However, while some of the frameworks include considerations for the underlying communication-specific aspects, mainly in relation to the industrial application requirements, they do not go into details with the integration and performance that specific wireless technologies may have when applied to specific applications. The wireless landscape in industrial scenarios is comprised by multiple different technologies with very different capabilities, with Wi-Fi being today the de facto connectivity option [8]. However, the performance and reliability of Wi-Fi varies largely depending on the specific environment and application scenario due to its operation over unlicensed frequency bands, where the spectrum is shared with other networks. As in such case, it is necessary to \"compete\" to access the medium for transmission, high reliability and quality-of-service levels might not be fulfilled under certain conditions [9]. As 5G was designed to provide better performance and higher levels of reliability and, since the first commercial 5G networks for industrial use are being deployed [3], it is now time to ensure that the full potential of 5G is properly evaluated and demonstrated within the context of industrial use [10]. However, we are witnessing a lack of proper use case analyses, performance evaluations and development of guidelines addressing the integration of wireless technologies within the different I4.0 applications but also within the overall digitalization processes. From a 5G perspective, the envisioned flexibility targeted by the I4.0 concept will require a proper assessment of the integration of the networking elements with the individual applications or use cases [11]. Thus, the objective of this paper is to propose an experimental framework for 5G wireless system integration into Industry 4.0 applications. This framework defines an industrial automation operational flow structured in different steps aiming at demonstrating, evaluating and optimizing the feasibility of operating specific industrial use cases over 5G in realistic factory conditions.