Countdown to main line 5G

A new era is dawning for main line railways. Work is now underway to finalise a new 5G-based standard for train-to-ground communications. Known as FRMCS (Future Railway Mobile Communication System), the standard has huge implications for the rail industry. 

Thales is actively involved in the development of the FRMCS standard and in the creation of technology to support it – including a brand new on-board gateway system for trains. The first commercial deployments of FRMCS are expected from 2026.

Why is FRMCS so important?

Modern railways depend on cellular radio for signalling and voice communications. Today, this is provided by a system known as GSM-R. While GSM-R is extremely reliable, the 2G technology behind it is now nearly 25 years old. 

GSM-R presents three specific challenges. The first is obsolescence. Telecom suppliers are switching their focus to new technologies such as LTE and 5G, so there is no guarantee that GSM-R will be supported in the long term.

The second challenge is capacity. GSM-R lacks the speed and bandwidth needed to support new, data-intensive applications. It is therefore acting as a brake on rail digitalisation.

Finally, there is the question of interoperability. Rail operators need an open communications standard and the freedom to use both private and public networks. GSM-R, however, is a rail-only standard and it depends entirely on private networks. 

Driving digitalisation with FRMCS

First and foremost, FRMCS solves the problem of GSM-R obsolescence. But equally important, it is designed to accelerate railway digitalisation.

Speed and capacity: because it is based on 5G, FRMCS offers extremely fast (low latency) connectivity, as well as a capacity to handle vast amounts of data, including live video. In addition, 5G makes it possible to connect thousands of IoT (Internet of Things) devices.

De-coupled architecture: FRMCS consists of a railway application layer, a service layer and a transport layer. One of the benefits of the separation of layers is that it makes it easier to manage multiple on-board applications, such as voice calls, signalling, Automatic Train Operation (ATO), video and IoT sensors. 

Private, public and hybrid connectivity: FRMCS can be delivered via both dedicated private networks (as GSM-R is today) and public networks operated by MNOs (Mobile Network Operators). Hybrid approaches – with both private and public connectivity – are also feasible. Trains equipped with an appropriate on-board gateway will automatically select the best radio link for the task in hand.

Future compatibility: FRMCS is designed to accommodate future telecoms standards, minimising obsolescence risk. By contrast, GSM-R cannot be upgraded to work with modern communications – it only works with 2G.

Brand new applications with FRMCS

FRMCS will support all of the functions currently handled by GSM-R. But it is more than just a like-for-like replacement. The superior capacity, speed and flexibility of FRMCS is designed to act as a catalyst for new and enhanced digital functionalities. 

Automatic Train Operation (ATO): this is a game changer when it comes to boosting reliability, capacity and energy efficiency. Modern ATO depends on train-to-ground and – in the near future – train-to-train communications. FRMCS makes provision for this and takes into account the need for real-time video to support advanced ATO functions.

Virtual coupling: this allows two or more separate trains sharing the same section of track to act as if they were a single train – boosting network capacity. Train-to-train data connectivity holds the key. Communications protocols for virtual coupling are already envisaged in the FRMCS standard. 

Autonomous trains: the FRMCS specification contains all the communications building blocks required to support autonomous train operation. While an autonomous train depends primarily on sensors to determine its position, high-speed communications between the train and the control centre will also be necessary – and FRMCS makes this possible.

Enhanced passenger information: FRMCS includes applications that contribute directly to passenger satisfaction, including public address and help points. Meanwhile, on-train telemetry communications make it possible to gather data about train positioning and even crowding on-board, paving the way for enhanced passenger information.