Division 7.2.1.3 Compatibility with other trains

An interoperable infrastructure may be used for the movement of trains not compliant with the requirements of this TSI, according to Article 5(4) of Directive 96/48/EC, provided this does not create prejudice to the fulfilment of essential requirements.

Such trains may use a class B signalling infrastructure, if existing. ERTMS/ETCS also offers the possibility of sending information for an on-board class B apparatus via class A track-to-train communication. If this solution is applied, in any case full ERTMS/ETCS functionality shall be installed trackside and the corresponding information shall be sent to the trains, to allow movement of interoperable trains. Trains equipped with on-board class B systems modified to receive information from class A track-to-train communication may not be declared interoperable.