# An Experimental Framework for 5G Wireless System Integration into Industry 4.0 Applications
## 3 Experimental Framework for 5G Integration
### Industrial Automation Operational Flow  
As illustrated in Figure 1, the proposed experimental framework is based on a sequential operational flow structured in six steps. Each of the steps has a different objective and makes different use of the lab environment and prototyping tools that are described in Sections 3.2 and 3.3, respectively. Figure 1: Flow diagram illustrating the different steps of the proposed industrial automation operational flow. * _Understanding the needs of the factory and its current level of digitalization: the factory is visited in order to get a good overview of overall operations and digitalization status. It is important, that during a first visit, common ground and common languages are established. Conversations are typically initiated with management, digitalization, research and innovation responsibles to learn about their views on 5G, the specific applications that they envision to run in their factories in the future, but also about those current applications that they would like to operate over wireless for improving the current production systems. Conversations are also held with IT responsibilities in order to understand the current wired and Wi-Fi network architectures, office and production network splits and network performance. With this information, we can feed the following steps of the operational flow with realistic information about the specific operational conditions required._
* _Understanding the exact communication requirements of the wired setup (data traffic analysis): in this step, that also takes place at the factory, a specific targeted I4.0 application is selected and the production area is visited--ideally, together with someone from both the IT and manufacturing departments, in order to have an overview of the exact machinery setting and its control network architecture. Further, a data traffic analysis is performed over relevant interfaces, candidates to be potentially operated over 5G, to understand and characterize the exact communication flows, protocols used, and the volume of data in different parts of the industrial system. This step is essential, as similar applications in different factories might implement very different control communication systems, and thus the more detailed the information, the better. It is important to check with the IT or production engineers about the control-loop latencies implemented in their systems, as well as survival times (sometimes called control failure times). These two parameters, together with the control architectures and the traffic statistics (throughput, packet sizes and inter-packet times) are essential information for evaluating whether the chosen application would be suitable for operation over 5G._
* _Selection of the appropriate wireless technology and dimensioning of the solution: based on the information collected in the previous step, we can analyze the suitability of 5G or other wireless technologies for coping with the targeted application and guide the factory about the most appropriate one. These could be done by simple \"pen and paper\" exercises based on requirements and wireless capabilities or via simulation/emulation. In general, the decision will be made according to capacity and control-loop latency requirements. High throughput time-critical applications could only be supported by 5G, while those applications that are delay-tolerant could be supported by 5G or other alternative technologies such as 4G or Wi-Fi (under very specific and optimized operational conditions) [9]. It should be noted that some of the most demanding applications might still not be supported by 5G, e.g., applications requiring sub-ms latencies, and in that case, legacy wired setups should still be used._
* _Deployment: once the wireless technology has been selected, i.e., 5G, the practical system integration begins. One or more of the relevant interfaces identified in STEP 2 are selected for integration of a 5G interface into them.