This part of IEC 62580, which is a Technical Specification, specifies the on-board video
surveillance/CCTV system functionality and requirement for the purpose of interoperability
between components of on-board video surveillance/CCTV systems in the same vehicle and
subsystems in different vehicles of the same train, which means two levels of interoperability
are considered, one is interoperability between components and another is between
subsystems.