Level 2 specification
NR/L2/TEL/30400/001
GSM-R Capacity Assessment for ETCS Traffic
Issue 1, 05 September 2026 · GSM-R & radio
How an ETCS project and DDaT Telecoms Operations work out whether the GSM-R cells along a route have enough voice and data capacity for ETCS, what inputs the project must supply, and the outputs and mitigation options
Clause map — what each clause deals with
| 1 | Purpose | Guidance on identifying GSM-R capacity requirements along a line of route ahead of ETCS |
| 2 | Scope | Voice and ETCS data between train and signalling centre, plus all other GSM-R voice (handportables and so on) |
| 3.1 | Parties involved in assessing capacity requirements | The RACI of who does what in the capacity assessment |
| 3.2 | Digital, Data and Technology Services (DDaT) Telecoms Operations | The asset owner's role — manages national GSM-R/FTN, assesses ETCS impact, designs mitigations |
| 3.3 | Delivery Project | The project supplies the ETCS capacity requirements, drawing on the signalling design |
| 4 | Definitions | Points to NR/L2/TEL/30400 for terms |
| 5.1 | Introduction | Compare installed GSM-R hardware against the capacity ETCS needs and find cells that fall short |
| 5.2 | Assumptions | Technical factors the project must assess — train schedules, cell sizes — and record as assumptions |
| 5.3 | Inputs to the Capacity Assessment Process | What the project gives DDaT: where onboard–RBC sessions start on run-in lines, registration rules at terminals and depots, train service data |
| 5.4 | Outputs from the Capacity Assessment Process | What comes back: channel quantities for voice/CSD/packet data per cell, BTS hardware and software parameters |
| 5.5 | Options Available | Mitigation options when capacity is short — additional carriers, cell changes, hardware |
| Appendix A | Information Exchange Examples | Example information exchanges between project and DDaT |