ERTMS Signaling levels
ERTMS/ETCS Level 1
Eurobalise without infill
- Overlay to Existing Signaling System.
- Movement Authorities through Eurobalise.
- Train Integrity & Position by Track Circuit.
Eurobalise + infill (euroloop, radio, or extra balises)
- Overlay to Existing Signaling System.
- Movement Authorities through Eurobalise.
- Train Integrity & Position by Track Circuit.
ERTMS/ETCS Level 2
Eurobalise + Euroradio + Radio Block Center
- No more Trackside Signals Required.
- Movement Authorities through GSM-R/FRMCS. Train Position via Eurobalise.
ERTMS Level 2/Hybrid Train Detection (HTD)
Eurobalise + Euroradio + Radio Block Center
- Movement Authorities through GSM-R/FRMCS. Authorities through Eurobalise.
- Train Position via Eurobalise.
- Train Integrity Onboard.
- Moving Block.
The concept known before as ETCS Hybrid Level 3 (HL3) is now newly referred to as ETCS Hybrid Train Detection (HTD).