FRMCS

What is FRMCS, the Future Railway Mobile Communication System?

General context

The European railways currently use the GSM-R system for train driver(s) to control operational communication, a key component of the European Railway Traffic Management System ERTMS.

Designed 20+ years ago by UIC and completely border-crossing interoperable, GSM-R, which is a 2G+ based system, is deployed on more than 130,000 kilometres of track in Europe (with 90,000 activated On Board Cab Radios), and some 210,000 kilometres worldwide.

The Future Radio Mobile Communication System (FRMCS) is the Railways’ response to two elements of strategic importance for the future of the railways:

First – the fast-coming GSM-R obsolescence, which is a European (and Global) level risk for Railways’ ERTMS continuity. End of support for GSM-R is expected around 2035.

Second – it is also a significant opportunity to enable and improve the Railways Digitalisation, and therefore the need to transmit, receive and use increasing volumes of data, which is at the very heart of sustainable transport.

These considerations led UIC to launch the studies for a successor to GSM-R, pertinently named Future Rail Mobile Communications System (FRMCS), and to put in place a solid organisation capable of building the FRMCS specifications, and also to monitor and be directly involved in the relevant activities related to FRMCS introduction.

The UIC FRMCS activity is developed and governed via the following working groups:

• The FRMCS Functional Working Group (FWG) ensures the adequate matching between system functionalities and railway needs
• The FRMCS Architecture and Technology Group Working Group (ATWG) has the mission to define the FRMCS architectures and the system requirements
• The FRMCS Telecom On-Board Architecture has the mission to define the On-Board FRMCS that uses the acronym TOBA architecture and functional requirements
• The UIC Group for Frequency Aspects (UGFA) takes care of the expected needs for spectrum, particularly sensitive in the transition scenarios
• FRMCS FIS (Functional Interface Specifications), defining the call flows to determine any gaps or inconsistencies
• FRMCS FFFIS (Form-Fit-Functional Interface Specifications), defining the On Board and Track Side Applications interface, responsible for the definition of the FRMCS border interface specifications
• 3GPP Task Force, representing Railways in 3GPP working groups (functional, architecture, solution, radio)
• We have also launched an FRMCS Test Specification task force that is developing, aiming to make available FRMCS Test Specifications that will support FRMCS V3
• The FRMCS Steering Group leads the global FRMCS strategy and planning, aligns these activities
• The working groups’ activity is monitored and oriented by ERIG, the UIC forum of Heads of Telecom. This also includes important projects like 5GRail and EU-Rail “FP2 MORANE2”, even if these projects have different governance

These UIC working groups are interfaced with UNITEL, ERA, and ETSI TC RT.

The missions of these groups also encompass the following key activities:

• Build and deliver the FRMCS specifications:
  • FRMCS FRS
  • FRMCS SRS
  • FRMCS TOBA FRS
  • FRMCS FIS
  • FRMCS FFFIS
  • FRMCS Test Specifications

• Support railway needs in 3GPP specifications forums
• Support railway needs in Frequency regulatory forums, obtain dedicated frequencies for FRMCS in Europe

The build and delivery of the FRMCS Specifications follow the European Process, as they are meant to be introduced in CCS TSI.

The FRMCS specifications will be completed with ETSI Technical specifications, delivered by the ETSI Railway Telecom Technical Committee.

The current FRMCS introduction situation is:

FRMCS Frequencies (additional to GSM-R) have been secured in Europe, see ECC (20) 02.

Version 1 (V1) of the FRMCS Specifications has been finalised following the UIC and ERA Change-Control management processes.

FRMCS have been included in the 2023 CCS TSI:

• FRMCS introduced as GSM-R successor
• GSM-R and FRMCS are jointly referred to as Railway Mobile Radio System(s) – RMR
• FRMCS will operate alongside GSM-R (until sometime in 2035)
• The FRMCS V1 specifications are introduced within the TSI Annexe A. These specifications are currently considered for procuring products.

The specifications development, together with FP-2 MORANE2, a project co-financed by DG Move and SNS JU is part of the global plan, as presented in the EU-Rail System Pillar Report on FRMCS V2 and V3 Scope and Planning (ref. SPG-STG-D-SPG-076-01).

A key part of this plan is the delivery by UIC, in the frame of its FRMCS Program, of the FRMCS V3 specifications, also named “FRMCS 1st Edition”, corresponding to the first implementable version of the new system, for their inclusion in a new CCS-TSI in 2027.

As per this global planning, in April 2021, the FRMCS specifications were updated to version 2.1.0.
There is a consequent need to verify, complete or amend these V2 Specifications that include so-called V3 target requirements through a full testing of FRMCS functions and system, on multiple lab and field test beds, leading them to market-ready V3 Specifications.

This operational testing is precisely the objective of FP2- MORANE-2 (MObile radio for RAilway Networks in Europe), a project that started in December 2024, and will last for 34 months.

We are currently in the process of finalising specifications development and refinement, in such a way that with the finalisation of FP-2 MORANE-2, we will deliver V3 specifications as per the planning.

Contacts

Dan Mandoc, Head of FRMCS
mandoc at uic.org

Jean-Michel Evanghelou, Director Telecom & Signaling, ERIG Chairman
evanghelou at uic.org

FRMCS Documents

UGFA Report technical aspects

UGFA Whitepaper on migration scenarios

FRMCS Specifications

Other Regions

The UIC FRMCS Specifications are intended for global use, much like the current UIC GSM-R Specifications. With this in mind, the UIC has been exploring the worldwide application of FRMCS.

However, certain countries may face challenges in accessing the 5G framework and technologies due to factors such as unavailability or high cost of 5G spectrum, national 5G development schedules, and the cost of owning 5G technologies.

These countries might also encounter early migration constraints and time-to-market issues. To address these challenges, a specific Technical Guideline, known as FRMCS-Transition (“FRMCS-T”), was developed.