As David Briginshaw reports from Paris, FRMCS will be designed for 5G and is seen as a game changer for railway digitalisation.

THERE is no doubt that GSM-R, the telecommunications element of ERTMS, has been a great success as its deployment far exceeds that of ETCS. GSM-R has been installed on 140,000km of track in Europe and 210,000km worldwide compared with 25,167km (contracted) for ETCS in Europe and 95,589km globally. GSM-R provides seamless 2G+ connectivity between track side and on-board, improves safety through the Railway Emergency Call system and enables ETCS.

But the telecoms world has changed beyond recognition since the specifications for GSM-R were finalised in 2000. GSM-R is a 2G system whereas in the wider world the first 5G systems are being deployed this year. GSM-R is based on GSM technology which is nearing the end of its life while GSM-R sub-systems face obsolescence. GSM-R lacks the capacity to transmit the volumes of data needed today let alone in the future. Although the railway supply industry has guaranteed continued support for GSM-R until 2030, time is short given the effort required to develop, test and approve a new system, and then to start the rollout which is expected to run from 2025 until 2035.

The UIC’s objective is to provide standards for the FRMCS system that allows flexibility for the implementers but still guarantees a system that is future proof, cost effective, fit-for-purpose and interoperable among the networks

The International Union of Railways (UIC) started the first studies for a successor to GSM-R in 2012. This led to the decision to develop the Future Railway Mobile Communication System (FRMCS) as a worldwide standard for railway telecommunications. The UIC has brought together leading European railway associations and railways as well as the telecoms standardisation bodies ETSI Technical Committee for Rail Telecommunications (ETSI TC-RT) and the 3rd Generation Partnership Project Technical Specifications Groups (3GPP TSG).

On May 14-15, the UIC held its first global FRMCS conference in Paris to reveal what has been achieved so far and outline the strategy ahead. “FRMCS is not being developed simply to replace GSM-R,” Mr Marc Antoni, the UIC’s rail system director, told delegates in Paris. “FRMCS is an enabler for game-changers such as ETCS Level 3 and ATO, a support for virtual coupling, smart maintenance, monitoring of trackside components, and connections between trains and traffic management systems.”

This view of FRMCS was reinforced by Mr Dan Mandoc, the UIC’s FRMCS director. “We plan to deliver FRMCS with, as a minimum, the same functionalities as GSM-R: train radio voice applications and ETCS data. However, FRMCS will also be an ERTMS game-changer, and an enabler for railway digitalisation,” Mandoc says. “The UIC’s objective is to provide standards for the FRMCS system that allows flexibility for the implementers but still guarantees a system that is future proof, cost effective, fit-for-purpose and interoperable among the networks.

“There will be three main work directions to provide the baseline platform for the system definition and delivery covering user requirements; system architecture interfacing with trackside and on-board equipment, and the frequency spectrum,” Mandoc explains.


The FRMCS project will investigate and perform studies for further improvement or opportunities related to sharing infrastructure, spectrum or other resources and the use of commercial non-specific equipment, based on an application approach.

The project will provide an appropriate replacement for the European Integrated Radio Enhanced Network (Eirene) Functional Requirement Specification (FRS) based on the user requirements. It will investigate future needs and add new functionalities. FRMCS will be technology independent, future proof, have an application layer approach, and will enable interoperability. Finally, FRMCS will provide an appropriate replacement for the Eirene System Requirement Specification (SRS) based on 3GPP and ETSI specifications, defining building blocks and interfaces, providing communication service to the application layer, and ensure interoperability.

Behind the FRMSC project, a steering committee will report to the UIC and the European Radio Implementers Group (Erig), and three working groups will cover functionalities, system architecture and technology, and frequencies (Ugfa). The project will also work closely with the Telecom On-Board Architecture (Toba) working group, and will interface with the EU Agency for Railways, two European railway associations (CER and EIM), ETSI TC RT, 3GPP, Unitel, and other interested parties.

“FRMCS is designed to be a flexible and a future proof system,” Mandoc says. “It will be able to follow the evolution of radio access technologies.”

FRMCS will need to have dedicated spectrum available for critical applications.

The transport system will provide the bearer Quality of Service and the priority handling, therefore critical applications, such as ETCS and ATO, will need to be Quality of Service aware, and 3GPP standards are already available for this approach. “Interoperability between communication networks can be guaranteed as long as the transport system, communication services and the mission critical applications are standardised,” Mandoc explains.

“FRMCS will need to have dedicated spectrum available for critical applications. Railways’ needs for train performance and intelligent infrastructure must also be covered and will turn out to be far more significant in quantity than current ones.” The FRMCS frequencies will be included in the 3GPP standards. 3GPP Mission Critical communication standards will be enhanced by railway requirements which envisage the use of 5G and beyond and aim for commercial off-the-shelf (Cots) equipment.

Close cooperation

FRMCS will be based on 3GPP building blocks. An FRS and an SRS will provide a foundation for the operation of FRMCS networks and guarantee interoperability for cross-border operation. The FRS and the SRS will complete the FRMCS system and will be the base in the CCS TSI for train radio and ETCS critical applications.

“The UIC is working in close cooperation with the EU Agency for Railways and stakeholders on these specifications,” Mandoc says. “We are currently agreeing with Shift2Rail the testing approach, common purpose demonstrators, synergies and convergence.”

A timetable has already been worked out for the implementation of FRMCS. The V4.0 user requirement specification (URS) was published in the first quarter of this year, and V5.0 should be ready in the first quarter of 2020, followed in the fourth quarter by the FRS framework and FRS V1.0 in mid-2021. Meanwhile the on-board URS should be completed by the fourth quarter of this year, with the on-board FRS following in Q4 2020 and the on-board SRS in Q1 2021. SRS elements should be ready next year and SRS V1 in Q3 2021.

“After just one year of work we have a plan,” Mandoc declares. “The overall objective is to have an FRMCS demonstrator in 2023 and conduct the first national trials in the fourth quarter of 2024. We will carry out testing under 4G in order to be ready for 5G deployment.”

There are various initiatives on cyber security in the railway world which are procedure, normalised, or analysis oriented, but the clock is ticking, Antoni says.

Security will be paramount for FRMCS. “We must consider all the safety, physical security and cyber security aspects,” Antoni says. “If the consequences are unacceptable, we have to avoid them by design.”

Antoni says the UIC has put forward an approach to cyber security. “There are various initiatives on cyber security in the railway world which are procedure, normalised, or analysis oriented, but the clock is ticking,” Antoni says. “IP/MPLS fixed networks are deployed in the railway world and FRMCS 5G will accelerate the trend towards full IP architecture, but the move towards IP is opening railway networks to cyber threats. Railways need to start to concentrate now on solutions provided by specialists. Changes induced by FRMCS and IP/MPLS are the opportunity to integrate this.

“The UIC will launch a cyber security solutions platform in September to assess solutions, concentrate on critical elements of the railway system, and consider them from the telecoms angle,” Antoni reveals.

Antoni says the platform will target protection for safety, security and availability, and the architecture for an IP evolution by integrating cyber security. The platform will:

  • define priorities for critical networks
  • register existing telecom cyber security groups
  • cooperate with companies specialised in cyber security
  • provide a platform for presenting solutions and highlighting the gap with railway needs
  • categorise solution versus critical needs, and
  • provide an annual guideline of technical solutions.

“The real problem with cyber security comes from telecommunications,” Antoni explains. “We need to cooperate to achieve an efficient, safe and secure railway.”

Spectrum challenges

The FRMCS project aims to obtain spectrum in the 900MHz frequency band as well as the 1900 and/or 2300MHz frequencies for the migration period as the 900MHz band will be insufficient for the migration from GSM-R to FRMCS. The FRMCS project plans to secure 5MHz in 900MHz and access to 1900MHz and/or 2300MHz after migration.

However, as Mr Didier Chauveau from the French National Frequency Agency, points out: “Rail is looking at the 900MHz spectrum, which is very attractive, but others are also looking at this spectrum. Rail needs to be careful in selecting the right band.”

Chauveau points out that the 1900-1920MHz band is the former 3G band granted to mobile network operators which will become available soon as their licences expire, and so could be used for the FRMCS macro coverage rollout. However, he says obtaining 10MHz in the 2290-2400MHz band is less likely as it is increasingly used by defence systems and is the main band for CCTV, although some countries have started to grant commercial mobile licences in part of the band.

More flexibility

GSM-R is an inflexible system as it is treated as one block. According to the architecture and technology working group (ATWG), FRMCS will decouple applications, services and transport to allow independence and transport bearer flexibility. “We will move from a voice-centric to a data-centric approach,” says Mr Ingo Wendler from the ATWG. “Decoupling allows more services - we currently have some restrictions when using public networks. FRMCS will also give more flexibility for interoperability.”

As GSM-R will not be part of FRMCS, an inter-working function is envisaged to provide the necessary procedures for voice and data for both systems during the transition phase.

Mr Matthias Ruete, who was recently appointed as the European Commission’s ERTMS coordinator, does not want the switch from GSM-R to FRMCS to be used by infrastructure managers or operators as an excuse for delaying the roll out of ETCS. “The days of GSM-R are numbered, so I want to insist that this will not hinder us with our ambitious ERTMS deployment plan,” Ruete told delegates in Paris. “We have to continue with ERTMS deployment and we will announce a very ambitious ERTMS on-board deployment strategy in the next few months.”

Ruete set out three things to avoid and three things to ensure for the FRMCS project. The three “don’t” are:

  • don’t undermine the current deployment strategy - FRMCS will require five-to-six years for the first suppliers to be ready with equipment and the two systems, GSM-R and FRMCS, will have to coexist and run in parallel
  • don’t endanger compatibility - backwards compatibility must be guaranteed and Baseline 3 should be the basis, and
  • do not create sunk investments - investment in existing equipment should be protected as much as possible.

“I am convinced that we can use most of the traditional infrastructure,” Ruete explains, which should make it easier for infrastructure managers to make a business case for FRMCS.

Ruete’s three things to ensure are:

  • ensuring sufficient spectrum by finding the optimum between member states and other industries
  • ensuring a smooth transition as dual trackside equipment will be there for some time, and
  • developing a concrete industrial vision with as much standardisation as possible to achieve significant reductions in unit costs.

“We should not develop proprietary solutions for rail as it will make it very costly,” Ruete adds. “We must plan a transition from GSM-R to FRMCS with a defined timescale. We must also plan for the decommissioning of legacy Class B signalling systems. This is the only way to get the full benefits of ERTMS. We must also clean up national operating rules even more strictly than we are currently doing.

“FRMCS must be fully interoperable, with simplified off-site testing procedures. We need research and innovation to develop a simpler on-board installation than we have now.

“I am convinced that FRMCS will be a key component of a digital railway network, but we must be aware of the cyber security threats from the outset, otherwise we will have big problems. We must also be able to integrate new functions in the future such as satellite signalling.”

Mr Boris Gombac, chairman of the UIC’s Operators and Functions Group, believes that GSM-R will be around for the foreseeable future. “Taking into account that some GSM-R migrations are planned to be finished between 2022 and 2025, as well as the life cycle of railway equipment, we can conclude that GSM-R will be in operation for at least 10-15 years and probably even longer in some countries.”

This means there may need to be some funding mechanism, or possibly a legal requirement, to encourage railways to make the switch to FRMCS earlier than they might if left to their own devices.

Mr Josef Doppelbauer, executive director of the EU Agency for Railways, pointed out that the next upgrade of the EU’s Control Command and Signalling Technical Specifications for Interoperability (CCS TSI), which covers ETCS and GSM-R, is due in 2022-23, which means it needs to be able to take account of FRMCS. “As a major precondition, we will propose a modular architecture in the new CCS TSI,” Doppelbaurer told delegates. “I see FRMCS as the starting point for increasing railway resilience. Cyber security is a must and we must have it from the very beginning. I also want to invite the supply industry to lead the standardisation effort.”

Doppelbauer emphasised the need to focus on migration to minimise the cost and the time to implement FRMCS, and not to repeat the mistakes made with ETCS. “After almost 30 years, ETCS has not been a shining example of fast migration,” he pointed out.

Mr Giorgio Travaini, head of research and innovation with Shift2Rail, emphasised the need to future proof FRMCS. “We must have a future-proof modular architecture and we must be able to move from one generation to the next. We need to think now about the services that need to be developed, such as predictive maintenance and smart radio objects, and how we integrate them. We need to design FRMCS so that it is sufficiently modular and scaleable.”

Mr Kier Fitch, vice-president, transport, with the European Commission, offers some advice for the FRMCS project. “It is clear that FRMCS is a very important aspect of railway policy,” he told delegates. “The future of the railway has to be digital if it is to be more competitive and attractive, but the digital railway will only work if we deploy ERTMS. GSM-R is virtually deployed but ETCS is not.

“FRMCS must cut costs. It must rely much more on the commercial telecoms market in order to be faster to market. The next revision of the CCS TSI must make provision for ATO and FRMCS. This is earlier than you are talking about. The danger is that nothing will really happen if you don’t take action.”

Fitch emphasised the need for a more rapid path to migration than currently envisaged to avoid a lengthy period of dual operation of GSM-R and FRMCS.

“We are working with DG Connect on frequencies, so that we can use existing infrastructure and make more use of public networks,” Fitch says. “We want to involve manufacturers, railways, Unife and Shift2Rail.”

The last word must go to Mr Jean-Michel Evanghelou, head of telecoms and signalling with the UIC. “The UIC will continue to be involved in the maintenance of GSM-R for the next 10 years,” he confirms. “It is clear that industry is already engaged with us on FRMCS and some products are in the alpha phase. Migration is a key subject which needs to be addressed.”

The FRMCS project has already made considerable progress within a very short time and has a lot of enthusiastic support in the railway community, but time is of the essence if it is to meet the CCS TSI revision deadline in 2022 and be ready to start deployment by the mid-2020s.