Division Track-side installations:
United Kingdom
It is mandatory to fit a GSM-R track-side assembly in any new installation of the radio part of a CCS track-side assembly or in any upgrade of an existing installation, where this would change its functions, performance and/or interfaces. This excludes those modifications that might be deemed necessary to mitigate safety-related defects in the legacy installation.
It is forbidden to upgrade Class B train-radio systems unless a modification is deemed necessary to mitigate safety-related defects in the legacy system.
It is recommended to install GSM-R whenever the infrastructure or energy sub-system of a section of line already in service is to be upgraded, renewed or maintained when this entails an investment higher than at least ten times those associated with the installation of GSM-R facilities on that section of line.
After the radio part of a CCS track-side assembly has been upgraded, the existing Class B equipment may remain in use together with the Class A radio equipment, until a date foreseen by the relevant national plan(s), and subsequently by the EU master plan. The Railway Undertaking is not allowed to oppose the removal of the Class B radio done under such conditions.