scope:

The present document defines the contents of the User-to-User Information Element when used in the GSM-R environment. This includes the basic EIRENE features Functional Addressing, Location Dependant Addressing, Confirmation of High Priority Calls (including, but not exclusively, REC and eREC) and Presentation of Functional Numbers. In addition the present document defines layouts for further features: Enhanced Presentation of Functional Numbers, Enhanced Location Dependent Addressing, Driver's Safety Device alarm, Plain Text Messages, Presentation of the Functional Number of the initiator of a Railway Emergency Call and Alerting of a Controller. Finally, the present document describes the requirements to be followed by network operators to ensure compatibility and interoperability if they wish to define specific fields for national and/or network use. The details of such fields are outside the scope of the present document.