ETCS Balise groups

[Jerry1237]

Don't forget that some of the signalling system is on-board the rolling stock. Rarely does an [ATO/ATP] train rely on a single source for speed / direction even excluding the driver. Cambrian also uses GSM-R and odometry both of which have variable accuracy for various reasons. A balise does provide a very specific and imovable [if left alone] position marker.

However, I would also be keen to find out more for their application.