IEC 62888-4:2018 applies to the on board and on board to ground communication services, i.e. it covers the data communication using digital interfaces:
a) between functions implemented within the EMS;
b) between EMS function and other on board subsystems;
c) between EMS and ground communication services.
a) between functions implemented within the EMS;
b) between EMS function and other on board subsystems;
c) between EMS and ground communication services.