Dirk Schulz, Abdulkadir Karaagac ABB Corporate Research Ladenburg, Germany, dirk.schulz@de.abb.com, abdulkadir.karaagac@de.abb.com
Currently, 5G standardization efforts aim to deliver a common communication infrastructure that integrates wired and wireless media and converges all information technology (IT) and operational technology (OT) domain communication [1]. For half a decade, ABB has been active in shaping 5G technology from the automation perspective to unlock its value for customer applications.
5G seeks to support almost any industrial application – for example, asset telemetry data transmission, mobile workforce infrastructure, or time-critical control signaling – based on one set of technologies and using one infrastructure →02. While some of these applications may be run over public 5G networks, others would require the control of network resources and data security that only isolated, on-premise 5G networks can offer. Furthermore, 5G aims to converge OT (automation), IT and telecommunications onto the same wireless-centric network.
In this context, ABB and Ericsson have investigated the readiness of currently available 5G mobile broadband technology for use in process automation applications. These investigations have provided insights into network performance and understanding regarding viable approaches to 5G system configuration and management.
Value of common wireless infrastructure
The 5G ambition of providing a common wireless infrastructure leads to a wide range of value propositions →03. Most importantly, 5G allows just one set of infrastructure assets to deliver communication services to all applications and support any form of mobility. The technology also offers the flexibility to reconfigure production processes with less cabling or increase sensor coverage for better asset availability and product or process insight. Customers can choose to invest in and control these infrastructure assets or source connectivity as a service, making infrastructure cost scale with the value delivered by converged wireless connectivity. Instead of using multiple IT and OT wired and wireless systems and security solutions, one secure, high-availability infrastructure could serve all customer needs.
5G deployment and reality
Cellular standardization and development is a continuous process, and, like previous generations of cellular technology, 5G functionality will be delivered in increments. Each standard release focuses on a different class of application, starting with mobile broadband (release 15), which has been the basis for commercially available solutions and public networks since 2020. Subsequent standard releases 16 through 18 are partly finalized and focus on low-latency communication and massive numbers of Internet of Things (IoT) devices – though corresponding products and private or public networks are not yet commercially available. To date, 5G standards have, understandably, focused on the mobile consumer market requirements. It now makes sense for domain-experienced partners, here ABB and Ericsson, who understand both automation and 5G, to explore the differences between what emerging standards include and what is readily available and possible.
Putting 5G to the test
Fulfilling the value propositions outlined above requires 5G to be technically capable of replacing wired communication on an industrial system scale. This condition comes with the need for a detailed technology assessment and development of new features, specifically addressing the following questions relating to the provision of a complete automation solution such as that shown in →04:
• Performance: Is 5G able to run typical process automation applications over one and the same (converged) network infrastructure and how can Ethernet-based protocols such as PROFINET IO be run over a network based on IP? The relevant applications include regulatory core control with cycle times down to 250 ms, device and asset management, and IoT telemetry data collection. This first assessment does not consider motion control, sequence of events (SoE), or high-integrity communication for safety applications.
• Convergence: Can automation and telecoms applications be converged onto the same network infrastructure? Such convergence entails running core control and digital applications alongside video, voice, access control, etc., without compromising performance and without added investment beyond the converged network infrastructure.
• Automation: How can a whole cellular network be easily and securely operated from an automation perspective? Users with automation backgrounds – including operators, engineers and even networking experts – should not need detailed training or understanding of cellular technology [2].
• Security: Does 5G comply with network security needs, given the level of exposure from the use of wireless, Internet technology and application convergence →05?
To address these questions, tests and development activities were carried out by ABB and Ericsson on a dedicated lab network, illustrated in →04.
A particular highlight of the lab setup is the distributed 5G campus network set up between ABB’s research centers in Sweden and Germany and based on released Ericsson products. This so-called 5G non-standalone (NSA) network uses 4G/LTE for network management traffic and 5G New Radio (NR) connectivity to transmit industrial application traffic, such as monitoring or time-critical application data. No network operator was required – instead, a so-called local spectrum band (3.7 to 3.8 GHz in Germany and Sweden) was used [3].
On the application side, a simple control system consisting of an ABB AC800M controller and ABB Select I/O remote I/O, connected via PROFINET IO, was migrated to 5G. Instead of an Ethernet ring, the remote I/O was connected through redundant industrial 5G routers. A traffic generator was used to assess the scalability of such control applications and verify co-existence with, for example, digital services or telecommunications traffic.
Comparisons were made of communication latency and failover behavior (ie, reversion to a backup system) between the wireless 5G network and today’s fiber-based wired networks. To this end, low-level measurements were taken directly at the Ethernet interfaces of the controller and I/O devices →04.
To automate the operation of the cellular network, 5G configuration and management functions were built into the ABB Ability™ Edgenius edge/cloud platform. This step allows security-related 5G features – such as mutual authentication, usage control and secure communication – to be used through ABB’s automation environment, addressing requirements set out in the IEC 62443 cybersecurity standard.
Readiness of 5G for process automation
The leading 5G research question is about performance – ie, ensuring 5G can guarantee the latency and availability needed to replace cable-based communication. The lab performance tests showed that it is possible to achieve uplink and downlink latencies of 64 ms with 99.9999 percent availability only after optimizing the radio access network (RAN) settings of the 5G campus network. This improvement is sufficient to run regulatory control with a 250 ms cycle time →06. Lower latencies are possible if consecutive packet timeouts or late deliveries, or even lower availability, can be tolerated by an application. Furthermore, the replication of I/O data over two independent network paths allows applications to tolerate the failure of a 5G router or radio connection in the RAN and further improves the availability of the 5G communication service in a healthy system.
IP-based protocols such as OPC UA or Modbus TCP can be used to talk natively with 5G. Even PROFINET IO solutions with ABB’s AC800M and Select I/O can be achieved by using a Layer 2 Tunnelling Protocol (L2TP). With a suitable module configuration of the Select I/O, packet size limits introduced by the tunneling overhead can be avoided.
To scale a 5G system infrastructure for use with tens of thousands of I/O signals, hundreds of video cameras and mobile equipment, the efficiency of the network operation processes is of very high importance. For this reason, a management application programming interface (API), called 5G Network Exposure Interface, was developed by Ericsson and integrated into the ABB digital ecosystem to securely onboard and offboard cellular devices or configure and monitor quality of service (QoS) for individual data connections – eg, between a controller and a remote I/O – from within the automation environment. The API introduces the needed simplicity into the everyday operation of a 5G cellular network without compromising security or performance from the management perspective →07. Integration of the API makes use of the existing 5G security mechanisms, using strong cryptography first to provide mutual authentication between industrial 5G routers and 5G networks and then to encrypt communication over the air.
The next steps
As described above, out-of-the-box 5G mobile broadband technology comes with limits related to industrial use, particularly in time-critical applications. However, ABB and Ericsson overcame those limits in IT/OT-converged networks. Remedies included performance optimization to use 5G for regulatory control at 250 ms cycle time; operating the 5G network securely and simply from within the automation system, ie, with no particular cellular expertise or support from a network operator; and finding best practices for selecting and configuring the communication devices. Using local industrial spectrum (where available) puts control of this critical resource into the hands of plant owners for a nominal fee.
While the lessons from this joint technology development are being taken from the lab into the next generation of products as well as into standards in the 3GPP or 5G-ACIA communities, 5G is generally ready for use in pilot tests or front-end engineering design (FEED) studies in real process environments. In addition to control and asset management, mobile workforce aspects and the integration of mobile equipment can also be converged onto one 5G network.
Acknowledgements
The authors wish to acknowledge the outstanding contributions of colleagues from ABB Corporate Research, Västerås, Sweden and of colleagues in Ericsson R&D
References
[1] D. Schulz, “5G for Digital Industries,” ABB Review 1/2020, pp. 30 – 36.
[2] 5G-ACIA, “Exposure of 5G Capabilities for Connected Industries and Automation Applications, 5G-ACIA, Whitepaper,” Feb 2021. Available: https://5g-acia.org/wp-content/uploads/WP_039_Network-Exposure-Interface.pdf. [Accessed July 12, 2022.]
[3] Bundesnetzagentur, “5G spectrum fees for local usages.” Available: https://bundesnetzagentur.de/SharedDocs/Pressemitteilungen/EN/2019/20191031_LokalesBreitband.html. [Accessed July 12, 2022.]
