scope:

The present document specifies the stage 3 description of the Supplementary Service Talking Party Identification (SS-TPI) for the Terrestrial Trunked Radio (TETRA). The SS-TPI supplementary service enables the party/parties participating in a call to receive the identification of the talking/sending party. The SS-TPI is activated against individual identity in individual call and against group identity in group calls. Man-Machine Interface (MMI) and charging principles are outside the scope of the present document. The supplementary service stage 3 description is preceded by the stage 1 and the stage 2 description of the service, according to the method described in ITU-T Recommendation I.130 [10]. The stage 1 description specifies the service from the user's point of view. The stage 2 description identifies the functional capabilities and the information flows needed to support the supplementary service as specified in its stage 1 description. The present stage 3 description specifies the protocols at the air interface and at the various Inter-System Interfaces (ISI) to support SS-TPI.