scope:

The present document defines the stage 1 specifications of the Area Selection (AS) supplementary service for the Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D). Stage 1 is an overall service description from the users point of view but does not deal with the details of the human interface itself. The present document specifies the service description of the supplementary service and the procedures to be expected with successful and unsuccessful outcomes. In addition the present document specifies the interactions with other TETRA supplementary services and interworking considerations. Charging principles are outside the scope of the present document. Area Selection (AS) allows an authorized user to define areas for selection and a served user to choose, on a call by call basis, a selected area to be used for establishing a call.