Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 12: Supplementary services stage 3; Sub-part 23: Call Completion on No Reply (CCNR) (V1.2.1)
The present document specifies the stage 3 description of the Supplementary Service CCNR Call Completion on No Reply for the Terrestrial Trunked Radio (TETRA). Call Completion on No Reply allows a calling user A@ encountering a destination user B which does not answer the call@ to have the call completed when user B becomes non busy after a period of activity@ 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. NOTE: According to ITU-T Recommendation I.130 [i.1]@ the stage 3 description of any telecommunication service addresses the network implementation aspects. Consequently it comprises two steps: the specifications of all protocols at the various reference points involved in any of the service procedures (notably the service operation) are the first step of the stage 3 description@ and the specifications of the functions of the corresponding network entities are its second step. The latter have not been provided since they can be derived from the specification of the functional entity actions in the stage 2 description. The present document is applicable to Voice plus Data individual call; the present document is neither applicable to Packet Mode of Operation nor to DMO; more specifically the present document is applicable to the following entities: ? the MS of either the calling user or the connected user during an individual call; ? the originating Switching and Management Infrastructure (SwMI) in an individual call; ? the terminating SwMI in an individual call; ? the inter-working SwMI for an individual call.