# Emerging Trends in Hybrid Wireless Communication and Data Management for the Industry 4.0
## 2 Use Cases and Requirements  
### Selected Industrial Use Cases  
The evolution of current communications and data management solutions to support the factory of the future is driven by a series of envisioned use cases and their communication requirements. The International Society of Automation (ISA) classifies the industrial applications in six different classes based on the importance of message timeliness [15]. The 5 GPP classifies industrial use cases in five families, each of them representing a different subset of communication requirements in terms of latency, reliability, availability, throughput, etc. [16]. ETSI has also investigated the communication requirements of industrial automation in [17] and classifies them in two broad groups: sensors and actuators for automation with real-time requirements, and communication at higher levels of the automation hierarchy e.g., at the control or enterprise level, where throughput, security and reliability becomes more important. The 3 GPP has recently identified in TR 22.804 V16.1.0 [18] a set of use cases and their communication requirements for the factory of the future taking into account all related studies for the design of the next generation of communication systems. The identified use cases are related to different application areas, such as process and factory automation, logistics warehousing and monitoring and maintenance, among others. Their main characteristics and communication requirements are described below. Motion control. A motion control system is responsible for controlling moving and/or rotating parts of machines in a well-defined manner, for example in printing machines, machine tools or packaging machines. Motion control has the most stringent requirements in terms of latency and service availability. Currently Industrial Ethernet technologies such as PROFINET(r) IRT or EtherCAT(r) are used for motion control systems. In order to support motion control, the 5G system should support a highly deterministic cyclic data communication service, although it is expected that there will be a seamless coexistence between Industrial Ethernet and the 5G system in the future. Control-to-control communication. This use case considers the communication between different industrial controllers (e.g., programmable logic controllers or motion controllers). This use case includes large machines (e.g., newspaper printing machines), where several controls are used to cluster machine functions, which need to communicate in real time with each other, and individual machines that fulfil a common task (e.g., machines in an assembly line) and that e.g., require controlling the handover of work pieces from one machine to another. Data transmission in control-to-control networks typically consists of cyclic and non-cyclic data transfers. Both types may have real-time requirements, but less demanding than for motion control. Mobile control panels with safety functions. Control panels are mainly used for configuring, monitoring, and controlling production machinery and moving devices. Safety control panels are in addition typically equipped with an emergency stop button for emergency situations. This use case requires the simultaneous transmission of non-critical (acyclic) data and highly-critical (cyclic) safety traffic with stringent latency requirements. Mobile robots. A mobile robot is basically a programmable machine able to execute multiple operations, following programmed paths to fulfil a large variety of tasks, including assistance in work steps and transport of goods. Mobile robots are normally controlled from a guidance control system to avoid collisions and assign them driving jobs. In this case, non-real time data, real-time streaming data (video operated remote control), and critical real-time control data need to be transmitted over the same link and to the same mobile robot. Massive wireless sensor networks.