# Towards Flexible Integration of 5G and IIoT Technologies in Industry 4.0: A Practical Use Case
## 1 Introduction  
Currently, a revolution is taking place in the way manufacturing processes are being designed. This revolution, generally labeled Industry 4.0 [1], envisions fully interconnected scenarios in the manufacturing industry to improve the efficiency, quality, and performance of the manufacturing processes. Industry 4.0 embraces the use of information and communication technologies in industrial scenarios to achieve a greater smartization and autonomy of the manufacturing processes through the integration of cyber-physical systems and the interconnection of machines, devices, sensors, and people. On 1 June 2017, the European Parliament adopted a resolution on developing an integrated industrial digitalization strategy for the EU [2], highlighting \"a cutting-edge digital infrastructure\", as one of its four pillars. This pillar targets not only applications but also infrastructure improvements. It is precisely in the delivery of this flexible, agile, and resilient infrastructure and in the evolution towards fully interconnected scenarios where communication technologies can play a decisive role. Two of these technologies that are additionally concerned with this article are Network Functions Virtualization (NFV) and Software-Defined Networking (SDN), both of which are considered keyenablers of the fifth generation of mobile networks (5G) to achieve a flexible and agile network platform over which to deploy heterogeneous services [3; 4]. These technologies represent an evolution towards the softwarization and virtualization of the network infrastructure and the network functions. The integration of NFV and SDN in the manufacturing industry (Figure 1) can greatly simplify the design and deployment cycle of new and innovative manufacturing services while achieving better utilization of computing and networking physical resources. In contrast, traditional network architectures present several shortcomings in regards to flexibility, accessibility, and dynamicity that can be further aggravated in industrial scenarios where the coexistence with heterogeneous devices, machine tools, and industry-specific protocols is a reality. These problems and limitations can be summarized as follows:  
* Deployment times of new services are slow and often involve the acquisition of dedicated hardware components to support specific functionalities. This is also tied to an inefficient use of hardware resources. Not only does this have an impact on the deployment costs, but also on the overall quality of the manufacturing processes. It can also negatively impact innovation in the manufacturing industry. * Services are difficult to re-utilize. A solution specifically deployed for a given manufacturing process or machine tool may be directly applicable to satisfy the requirements of other ones. However, there are no convenient mechanisms to ease the re-utilization of services in such cases, often leading to duplication of efforts and resources in setting them up. Figure 1: Integration of Industry 4.0 with Network Functions Virtualization (NFV) and Software-Defined Networking (SDN). * Configurability of services is limited. Solutions are deployed rather statically and the lifecycle management or reconfiguration of a service often requires significant manual intervention and hardware manipulation, and sometimes even the acquisition of additional hardware components. * The isolation between different business processes is difficult to enforce and manage. The concerns in relation to the privacy and security of critical data mean that some processes are not connected to a shared network infrastructure or to the Internet, limiting their capabilities. The Industry 4.0 paradigm also envisions the integration of Industrial Internet of Things (IIoT) technologies [5]. These technologies consist of a massive deployment of interconnected devices which are responsible for gathering, analyzing, sending, and monitoring data on a large scale.