This part of IEC 61375 applies to data communication in Open Trains, i.e. it covers data communication between consists of the said open trains and data communication within the consists of the said open trains. The applicability of this standard to the train communication bus (WTB) allows for interoperability of individual consists within Open Trains in international traffic. The data communication bus inside consists (e.g. MVB) is given as recommended solution to cope with the said TCN. In any case, proof of compatibility between WTB and a proposed consist network will have to be brought by the supplier. This standard may be additionally applicable to closed trains and multiple unit trains when so agreed between purchaser and supplier. NOTE 1 For a definition of Open Trains, Multiple Unit Trains and Closed Trains, see Clause 3. NOTE 2 Road vehicles such as buses and trolley buses are not considered in this standard.