# Emerging Trends in Hybrid Wireless Communication and Data Management for the Industry 4.0
## 6 RAN Slicing for 5G Industrial Wireless Networks  
In a factory environment, several applications with different communication requirements (Section 2) will coexist under the same cell. Supporting the heterogeneous use cases and the stringent and varying communication requirements of the industrial applications in the factories of the future is a challenge that has to be faced by industrial wireless networks, as presented in Section 3. Current wireless technologies can support more than one type of application, even belonging to different verticals, each of them with possibly radically different communication requirements. For example, LTE or 5G networks can be used to satisfy the ultra-high reliability and low-latency communication requirements of time-critical automation processes. Moreover, LTE or 5G networks can also support applications that require high throughput levels, such as augmented reality or 4K/8K ultra high definition video. These different communications requirements in terms of transmission rates, delay, or reliability require specific and different communication management functions that cannot always be met through a common network setting. This fact requires industrial wireless networks to be highly flexible and capable of implementing different communication management functions adapted to the communication requirements of each application while ensuring that the application-specific requirements are satisfied independently of the congestion and performance experienced by the other applications supported by the same cell (i.e., performance isolation needs to be guaranteed between different applications). This is typically achieved through network virtualization and slicing which allow composing dedicated logical networks with specific management and functionalities. In addition, one important aspect is to ensure that the application-specific requirements are satisfied independently of the congestion and performance experienced by the other applications supported by the same cell, i.e., performance isolation needs to be guaranteed between different applications. In this context, we propose the use of RAN Slicing to solve the above-mentioned issues. RAN Slicing is based on SDN (Software Defined Networking) and NFV (Network Function Virtualization) technologies and proposes to split the resources and management functions of a RAN in different slices to create multiple logical (virtual) networks on top of a common network infrastructure [41]. Each of these slices, in this case, virtual RANs, must contain the required resources needed to meet the communication requirements of the application or service that such slice supports. As presented in [41], one of the main objectives of RAN Slicing is to assure isolation in terms of performance. In addition, isolation in terms of management must also be ensured, allowing the independent management of each slice as a separated network. As a result, RAN Slicing becomes a key technology to deploy a flexible communication and networking architecture capable to meet the stringent and diverging communication requirements of industrial applications, and in particular, those of ultra-reliable and low-latency (URL) communications. In the proposed architecture, each slice of a physical cell is referred to as virtual cell as shown in Figure 7. Each virtual cell implements the appropriate functions based on the requirements of the application supported and must be assigned the RAN resources (e.g., data storage, computing, radio resources, etc.) required to satisfy the requirements of the communication links it supports. Figure 7: Virtual cells based on Radio Access Network (RAN) Slicing. RAN slicing is already being studied by the 3 GPP. System architecture and requirements to support network slicing in 5G networks are already defined in [42; 43]. The 3 GPP also describes the management aspects of a network slice in [44], which are established in 4 lifecycle phases: preparation, commissioning, operation, decommissioning.