The future of rail transport critically depends on taking advantage of advanced communications systems to enhance safety, increase automation, cut operating costs and improve the experience for rail passengers. With the Future Railway Mobile Communications System (FRMCS) due to replace GSM-R and other legacy systems, rail operators need to begin now to plan how they will prepare and migrate their networks to take advantage of 5G-based FRMCS. 

While it has served the rail industry well for many years, GSM-R is maturing, with support largely terminating by around 2030. FRMCS is expected to serve railways for much longer, with likely implementation in the mid-2020s to provide reliable service extending over the next few decades. This means that for several years, GSM-R and FRMCS will run in parallel during the migration period. 

Rail operators currently using GSM-R are recommended to modernize their existing GSM-R networks by introducing IP technology, as in the transmission networks for FRMCS. On the radio front, the latest thinking of the UIC and the European Railway Agency shows a clear preference towards 5G, a choice supported by many major European railway operators. 

The UIC and ERA favor 5G as the wireless standard for a number of key reasons. First of all, unlike all previous mobile networking generations, including 4G, it is a highly flexible and modular architecture that can work with a variety of access technologies, including cabled Ethernet, Wi-Fi, point-to-point wireless, as well as LTE/5G cellular radios. This means it can leverage existing connectivity investments and will be able to evolve as new forms of access arrive. With this kind of flexibility, it is expected to serve railways for 15–20 years at minimum. 

Adding to this flexibility, the 5G NR (new radio) is a new global standard air interface for 5G networks. It is the most flexible way to benefit from all available spectrum options, currently spanning 600 MHz to 90 GHz, including licensed, shared access and unlicensed, Frequency Division Duplex (FDD) and Time Division Duplex (TDD) bands, narrowband and wideband allocations are possible, and new spectrum options can be continuously introduced. Using Massive MIMO technology, 5G radios are capable of even higher capacities than LTE/4.9G. 

The 5G core architecture is cloud-native, thus virtualized and modular for much greater scalability and a wider range of services. Much of this cloud technology is widely employed in cloud networks today and is, thus, both well-tested and inexpensive. The 5G network is software-driven and programmable, which makes it far more automatable and far easier to introduce new applications. The 5G core architecture is distributable, allowing some processing to be placed at the edge of the network, close to automated functions. This enables time-sensitive networking (TSN), with one-tenth the delays of LTE — in the range of 1–2ms. This will enable many new automated and remote operations.

Different users will have different demands on 5G networks with sometimes very diverse and extreme requirements for latency, throughput, capacity and availability. Supporting all these different uses cost-effectively from one common infrastructure can be achieved by network slicing. This enables, for instance, separate, dedicated railway operator networks, the separation of operational traffic from passenger traffic, or the use of public mobile operator slices for running non-mission-critical services. 

There are a number of applications that will make the most of these new capabilities. Along with operational voice services, mission-critical reliability is also required by ETCS. Predictive maintenance and operations intelligence will use IoT asset management and advanced data analytics to reduce costs, increase asset utilization, enhance safety, minimize delays and reduce revenue loss. 

Video surveillance for operational security using multiple, high-quality CCTV systems generating many video streams can also be supported by 5G. With its high-capacity and low latency connectivity, it will support applications that help improve passenger safety and security. These will include driver video for advance views of platforms and level crossings, as well as remote supervision of passengers through on-board closed CCTV. 

Such CCTV systems will also contain innovative features such as video analytics software to automatically detect obstacles on the track, strange behavior or unattended baggage. Of all types of application traffic for rail operations, CCTV traffic demands the most capacity, but paired with video analytics and edge computing, 5G will be able to handle this traffic without sacrificing resources for mission-critical services. 

The modern passenger expects to be connected constantly and be provided with personal, bespoke communications and services. Although of lower priority, this kind of passenger “infotainment” traffic can use significant capacity and pose a security risk if carried on the same infrastructure as operational traffic. 5G network slicing completely separate passenger traffic from operational traffic, ensuring the resources needed to maintain the required service levels for mission-critical operations are always available and secure.

The digital transformation of the railway has been underway for more than a decade now, but we are entering an exciting phase. New technologies such as IoT, machine learning and AI will enable use cases and applications that we can hardly even imagine today. Critical to all of these technologies will be a highly advanced, flexible and automatable communications system that ensures the capacity, responsiveness and security that railways will require. Over the next decade, railway operators will evolve to FRMCS. 

Some have already started trials and testing. For example, SNCF has formed a partnership with Nokia on 5G development. The objective of the collaboration is to create a 5G Lab that explores rail and non-rail use cases and, to prepare for the transition of GSM-R to FRMCS. Deutsche Bahn is also working with Nokia to test and deliver the world’s first standalone (SA) 5G system for automated rail operation as part of Deutsche Bahn’s highly automated S-Bahn operation project. The project constitutes an early and important step in the development of FRMCS standard based on 5G.

If you would like to learn more about how 5G can put you on the fast track to FRMCS. Download the Nokia white paper “A new platform for rail communications – adopting 5G for railways”.