scope:

The present document defines the stage 1 specifications [1] of the Supplementary Service Dynamic Group Number Assignment (SS-DGNA) for the Terrestrial Trunked RAdio (TETRA). 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 specifies the interactions with other TETRA supplementary services and Interworking considerations. Charging principles are outside the scope of the present document. The SS-DGNA enables a served user to dynamically manage groups.