08-08-2019, 04:14 PM
Peter is right that ETCS (and other transmission based systems) allows for the train to report its location to the trackside signalling system. Train reports are normally referenced to some fixed asset (such as a balise group in ETCS) and often include direction, offset distance from reference, speed and the potential error in the position report.
For ETCS Level 3 there may be no train detection (track circuits or axle counters) and hence the signalling will rely on reports from the trains on where they are (or were when they sent the report) and whether the train is intact (has integrity).
For ETCS Level 3 there may be no train detection (track circuits or axle counters) and hence the signalling will rely on reports from the trains on where they are (or were when they sent the report) and whether the train is intact (has integrity).