With three application profiles, 5G meets the requirements of a wide range of applications within a work unit:

- eMBB (enhanced Mobile BroadBand) offers data transmission rates of up to 20 GBit/s, for example for virtual or augmented reality applications.

- mMTC (massive Machine Type Communications) is designed to provide stable network coverage for up to 1 million MTC devices per square kilometer.

- uRLLC (ultra-Reliable and Low Latency Communications) creates the conditions for time-critical applications with latency times of less than 1 ms.

However, these benefits will only be fully available in the final 5G development stage with 3GPP Release 16, which is expected this year. It will then take some time before the corresponding products are available. However, this does not mean that companies should wait that long. Much can already be implemented with LTE/4G, which is being further developed with each release and will eventually lead to 5G. This is because the 5G New Radio (NR) radio interface will also support LTE, enabling a seamless transition from 4G to 5G. With 5G NR, antenna systems for beamforming and MIMO (multiple-input, multiple-output) are also available. These technologies make a significant contribution to increasing reliability and reducing latency.

Combination of 5G and LTE

A 5G campus network does not have to be based exclusively on 5G. Many industrial applications can also be implemented with an NSA (non-stand-alone) architecture, i.e. the combination of 5G with the existing 4G/LTE network. These include assembly support with augmented reality or the remote operation of machines. Only for applications that require extremely low latency times is an SA (stand-alone) architecture with a 5G access network including NR radio interface and terminals as well as a 5G core network a must.

In order to implement the various eMBB, mMTC and uRLLC use cases, the positioning of the antennas, network slicing to ensure the required bandwidth for time-critical applications, time synchronization between the individual units and security measures are also crucial.

The advantage of an NSA architecture is that companies can use their existing network infrastructure - wired or wireless - such as industrial Ethernet LAN, WAN, SD-WAN, PLCs or SCADAs. Even though CAT cables are more secure, migrating to WiFi 6 within the factory premises means that even the requirements of time- and safety-critical applications can be implemented without cabling, thus gaining more flexibility.

Interworking between 5G and 4G at the level of the access network (RAN, Radio Access Network) and the core network (CN, Core Network) is currently being discussed within the 3GPP. Technologies such as inter-band NR carrier aggregation or dual connectivity can be used to meet the frequency requirements. Here, lower frequency bands are aggregated if full coverage on high frequencies cannot be achieved using beamforming.

Example application: Digital Thread and Digital Twin

Carrier aggregation: Throughput can be increased by combining several cells with different frequencies.

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A demo by Tech Mahindra using Digital Thread and digital twins shows the possibilities that a 5G campus network offers for the manufacturing industry. It covers the entire value creation process, from order processing in ERP to product creation using PLM and digital instructions from MES through to equipment on the factory floor. An SD-WAN (software-defined wide area network) at the enterprise edge ensures connectivity within the factory and between the factory and the enterprise cloud. Possible use cases include

- Automated design, planning (creating design and manufacturing BOMs), assembly lines and robot control

- Pick and place robots in the assembly line

- Smart assembly with networked tools

- Vision-based inspection

- Condition-based maintenance (CBM) and predictive maintenance using a digital twin

- Augmented reality for plant maintenance

Selection of the frequency range

The actual power available on the factory floor depends, among other things, on the available and used spectrum.
The mid-band spectrum with frequencies between one and six gigahertz offers better network coverage than the low-band spectrum (below 1 GHz) and is therefore particularly suitable for indoor use - and therefore for most applications in production. In future, however, this will be the new high-band spectrum above 24 GHz, especially the new ultra-high frequency bands between 30 and 300 GHz. These mmWave bands allow data channels with a large bandwidth. As 4G and 3G operate at lower bandwidths, there is no interference from other devices in the millimeter wave spectrum, which ensures higher transmission speeds. However, it is not only the factory environment that plays a role in the choice of spectrum, but also the number of parallel connections required.

Another factor is the multiplexing technology. As 5G networks, including the mid-band spectrum, are based on time division duplex (or time division multiplexing) - i.e. the transmit and receive channels use the same frequency - precise phase synchronization is extremely important.

The complete migration to 5G will generally take place in stages. How long it takes depends on the type and size of the network as well as the requirements. In general, it is advisable to start with time-critical areas and applications. All others can follow as soon as future 5G versions have new capabilities, such as a multi-operator core network (MOCN) in which several core networks share an access network, or mission-critical services.

The safety requirements

The security architecture is based on five strata (layers with protocols and functions that belong to one aspect of the network services): Access, Transport, Serving, Home and Application. The diagram shows the security mechanisms and protocols defined for each layer, grouped into five security measures: Access (I), Network (II), User (III), Application (IV) and Visibility & Configurability (V).

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Numerous security functions are already integrated into the 5G standard, including for new 5G use cases. In addition to the usual security architecture that is also used in other mobile networks, there are several security functions under 5G specifically for industrial applications:

- User-level integrity protection prevents data changes when traversing the 5G spectrum.

- Device authentication supports SIM and certificate-based authentication.

- There is a hidden IMSI (International Mobile Subscriber Identity) with identity-based encryption.

There are also new trust boundaries, both for the Packet Core and for its interaction with other entities within the 5G network.

In addition to the built-in security, the company can implement its own security policies in its 5G campus network without being dependent on an external provider. It is crucial to retain complete control over the data in the OT (Operational Technology) area. To this end, critical data must remain local to the production unit, i.e. calculations must be carried out at the edge. It must also be ensured that connectivity within the production unit cannot be interrupted. For this purpose, the 5G NR antennas should be installed indoors below three meters according to version 16 of the 3GPP specification.

In general, a multi-pronged security approach must be pursued, which includes trust models, a key agreement and authentication (AKA, Authentication and Key Agreement) as well as a second authentication based on the Extensible Authentication Protocol (EAP). In addition, mobile network operators and companies should join forces to build an unbreakable security layer. In all IoT implementations, identity and access management must be considered at the core network and access network level as well as the end devices.

Tech Mahindra has developed a '5G for Manufacturing' suite specifically for manufacturing companies. With the end-to-end offering, companies can build their private 5G network.

Solution for manufacturing companies

Nilesh Auti is responsible for 'Manufacturing Vertical' at Tech Mahindra.

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Its three-tier structure - Device Edge, Enterprise Edge and Cloud - follows the principle of 'Shift Intelligence to the Edge': use cases that require low latency and are critical in terms of data security or data protection are implemented at the edge of the network. Data that is not latency-critical, such as for historical trends, management dashboards or machine learning, can be sent to the cloud. On average, 60 to 70 % of OT data is processed at the edge, with the remaining 30 to 40 % in the cloud.

The '5G for Manufacturing' suite includes a private 5G network, multi-access edge compute, SDWAN, a range of pre-integrated enterprise applications hosted at the edge or in the cloud, and a security overlay. This covers both the IT and OT areas, for example with DDoS protection, AntiBot, Deep Packet Inspection, Web Application Firewall (WAF), and also takes into account risks that may only arise through the increasing use of 5G. It also includes comprehensive services such as consulting, radio and network technology, engineering and application services as well as operation and maintenance.