The railway community is since 2015 working on the standardisation of FRMCS. The development of the future radio system is one of the “game changers” identified in the ERTMS Longer Term Perspective document of ERA. The Control Command System Technical Specification for Interoperability (TSI CCS) will incorporate FRMCS as the successor of GSM-R as the radio system to be used for train-to-track voice communications and for ETCS data communication, also supporting new railway functionalities such as ATO.

The work on functional requirements, specifications and standards as well as harmonised spectrum solutions is taking place and is carried out by UIC. The objective is to update the TSI in 2022 with a full description of the standard.

When assessing the status of the work, EIM thinks that achieving the timeline for updating the TSI in 2022 is ambitious and jeopardised by the complexity of the standardisation work (delivering a complete specification including suitable migration schemes) and the acquisition of harmonised spectrum.
At the same time, we acknowledge that FRMCS can only successfully and timely be introduced if a suitable migration scheme is in place which preserves investments and considers legacy ERTMS (and GSM-R) systems already installed in trains and infrastructure.
Although the standardisation work on migration is in progress, we think that the position of the stakeholders of the railway sector is important

1. There is a need to express the view of the sector on migration. It is important that the policy/regulatory makers (European Commission, ERA) have a good understanding of ambitions and target timelines of the sector;
2. The sector should provide guidance and governance on what to include in the upcoming CCS TSI in order to meet target timelines;
3. The specification work should be encouraged and supported.

In our view a smooth migration strategy is based on the following principles:

1. Migration of trains first, then infrastructure;
2. Realisation of a dual mode On-board architecture supporting GSM-R and FRMCS;
3. An early standardisation of the architectural framework and interfaces of the On-board considering potential long and diverse timelines of migration and life cycle management;
4. A sufficiently long period (e.g. 5 years) granted by the infrastructure manager regarding the implementation of FRMCS and GSM-R decommissioning.

As an example, some railways envisage that around 2025, an FRMCS service in the form of a public 5G network slice may provide an IP transport service with appropriate Quality of Service as a backup on some ERTMS tracks. Because trains will run on GSM-R and FRMCS infrastructure, a dual mode ETCS On-board is a necessity.