Section: 5.3.6.2.2 Mobile terminating multimedia call
Content: At call setup the required call type, 3G-324M, is indicated by the network in the SETUP message, with the bearer capability IE parameter. Other Rate Adaption set to 'H.223 and H.245'. ITC is either '3,1 kHz audio ex PLMN' or 'UDI/RDI'. For analogue multimedia, if the network supports fallback to speech and the subscriber has subscription to speech, two bearer capability IEs, multimedia first and speech as the second BC are included in the SETUP message. The network shall indicate fallback to speech by these two BC IEs and the associated Repeat Indicator set to "support of fallback". For UDI/RDI multimedia, if the network supports fallback and service change, and the subscriber has subscription to speech, two bearer capability IEs, with the first BC as the preferred service are included in the SETUP message. The network shall indicate service change and fallback by these two BC IEs and the associated Repeat Indicator set to "service change and fallback". If the bearer capability IE is received from the MS either in A/Gb or GERAN Iu mode and indicates no A/Gb mode support for the requested bearer service, the network shall consider it as a request to perform an inter-system handover to UTRAN Iu mode, as described in 3GPP TS 23.009[ Handover procedures ]  [114] subclause 14.2. The bearer capability IE(s) may (in the case of the single numbering scheme) be missing from the SETUP message. The bearer compatibility checking in the MS is according to subclause 5.3.4.2.2. The MS shall indicate the supported call type(s) in the CALL CONFIRMED message, which is the acknowledgement to SETUP. If the network offered an analogue multimedia call with fallback to speech, or a UDI/RDI multimedia call with fallback and service change, the MS has the following options for the inclusion of bearer capability IEs in the CALL CONFIRMED message: - if the MS/user accepts the offered analogue multimedia call and supports fallback to speech, both multimedia and speech bearer capability IEs shall be included; - if the MS/user accepts the offered UDI/RDI multimedia call, and supports fallback and service change, both multimedia and speech bearer capability IEs shall be included. The order of the BC IEs determines the preferred service, and the MS/user may reverse the order of these IEs; - if the MS/user accepts the offered multimedia call, but does not support fallback or service change, only a multimedia bearer capability IE shall be included; - if the MS/user wishes a speech (only) call a speech bearer capability IE is included; - for a UDI/RDI multimedia call, if the MS/user accepts the offered speech call and supports service change, both speech and multimedia bearer capability IEs shall be included. The order of the BC IEs determines the preferred service, and the MS/user may reverse the order of these IEs. If the network offered a multimedia call only, and the MS/user accepts the call, the MS shall always include a single multimedia bearer capability IE in the CALL CONFIRMED message. If the SETUP contained no bearer capability IE the network shall perform compatibility checking of the CALL CONFIRMED message in the same way as the compatibility checking of the SETUP message in the mobile originating call case, described in subclause 5.3.6.2.1.