scope:

The present document defines the stage 1 specifications of the Include Call (IC) supplementary service for the Trans-European Trunked RAdio as provided by European operators. 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. The IC supplementary service enables the served user, while having a call in progress, to make a new call and have the new party included in the original call. The present document applies to TETRA speech teleservices and speech bearer services only.