Certification of subsystems
Subsystems are as follows defined:
a) structural areas:
- Infrastructure,
- Energy,
- track-side Control-Command and Signalling,
- on-board Control-Command and Signalling,
- Rolling Stock;
b) functional areas:
- Operation and traffic control,
- Maintenance,
- Telematics applications for passenger and freight traffic.
For subsystems exists essential requirements. This basic definition of requirements are laid down in the technical specifications for interoperability (TSI).
All the above Directives and technical specifications (TSI) can be found under the heading "Information" under European legal bases und TSIs.