SSH EN 300 392-12-13 V1.2.1:2012

Terrestrial Trunked Radio (TETRA);Voice plus Data (V+D);Part 12: Supplementary services stage 3;Sub-part 13: Call Completion to Busy Subscriber (CCBS)

Scope

The present document specifies the stage 3 description of the Supplementary Service CCBS Call Completion on Busy Subscriber for the Terrestrial Trunked Radio (TETRA). Call Completion on Busy Subscriber allows a calling User A MS, encountering a busy destination user B, to have the call completed when user B becomes non busy, without having to make a new call attempt. Man-Machine Interface 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 [i.1]. The stage 1 description specifies the service from the user's point of view. The stage 2 description identifies the functional capabilities of each SS 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 each Supplementary Service.