IEEE Std 1474.4-2011 pdf download – IEEE Recommended Practice for Functional Testing of a Communications-Based Train Control (CBTC) System.
4.1.4 Application-specific requirements The correctness of application-specific data (i.e., infrastructure data, such as curves, grades, station locations, etc., and train-specific data, such as braking rates and response times, etc.) and that this data has been correctly implemented within the system databases, should also be verified as an element of the functional test process. When resignaling with a CBTC system, application-specific external (legacy) equipment interfaces, application-specific operating modes, and application-specific functional requirements are common. This can result in application-specific designs that should be reflected in the application-specific functional test process. To exploit the operational capabilities of CBTC systems, the design of a CBTC system is often integrated with the design of other fixed operating elements of a rapid transit system such as traction power systems, tunnel and station ventilation systems, passenger information and security systems, and backbone communications networks, for example. In addition, the designs of the onboard train location/speed measurement subsystems are also often application-specific due to vehicle-specific interfaces. As such, the performance of these application-specific designs should be verified through the functional test process. 4.2 CBTC applications The CBTC functional test process for resignaling applications can be significantly more onerous than signaling new lines, primarily because of the need to maintain revenue operations and the integrity of the existing signaling system during the migration to the new CBTC system, which in turn results in track access limitations and the need to support mixed modes of operation. In addition, the specific signaling/train control system being replaced is typically different from one application to another. The objective of the factory functional testing should be to verify to the maximum extent possible that all of the CBTC functional requirements have been satisfied. When testing a specific functional requirement, if the test outcome cannot be affected by factors outside of the test environment, it should not be necessary to have to repeat this test on the test track or in the field, i.e., such requirements should be fully verified through the factory testing. Where a factory test outcome is dependent upon simulated interfaces to the CBTC system, it would generally be necessary to repeat such tests either on the test track or in the field with the real interfaces, depending on the complexity of the interface and the ability to simulate the interface in the factory.