Section: 5.3.6.2.1 Mobile originated multimedia call establishment
Content: At call setup the required call type, 3G-324M, is indicated by the originating MS in the SETUP message, with the bearer capability IE parameter Other Rate Adaption set to "H.223 and H.245". For analogue multimedia, the support of a fallback to speech is requested by including two bearer capability IEs, multimedia first and speech as the second BC in the SETUP message. The MS shall indicate fallback to speech by these two BC IEs and the associated Repeat Indicator set to "support of fallback". For UDI/RDI multimedia, the support of a fallback and service change is requested by including two bearer capability IEs, with the first BC as the preferred service in the SETUP message. The MS shall indicate service change and fallback by these two BC IEs and the associated Repeat Indicator set to "support of 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 compatibility checking in the network is according to subclause 5.3.4.2.1. If the MS requested for an analogue multimedia call with fallback to speech, or for a UDI/RDI multimedia call with fallback and service change, and the network accepts the call, the network has the following options for the inclusion of bearer capability IEs in the CALL PROCEEDING message: - if the network accepts the requested analogue multimedia call and supports fallback to speech, both multimedia and speech bearer capability IEs shall be included; - if the network accepts the requested UDI/RDI multimedia call and supports fallback and service change, both multimedia and speech bearer capability IEs shall be included. The order of the bearer capability IEs determines the preferred service, and the network may reverse the order of these IEs (see 3GPP TS 23.172[ Technical realization of Circuit Switched (CS) multimedia service UDI/RDI fallback and service modification; Stage 2 ]  [97], subclause 4.2.1); - if the network accepts a multimedia (only) call, a multimedia bearer capability IE shall be included; - if the network accepts a speech (only) call, a speech bearer capability IE shall be included; - for a UDI/RDI multimedia call, if the network accepts the requested speech call and supports service change, both multimedia and speech bearer capability IEs shall be included. The order of the bearer capability IEs determines the preferred service, and the network may reverse the order of these IEs (see 3GPP TS 23.172[ Technical realization of Circuit Switched (CS) multimedia service UDI/RDI fallback and service modification; Stage 2 ]  [97], subclause 4.2.1); - if the network received a UDI/RDI multimedia bearer capability IE with FNUR equal to 32kbit/s and a speech bearer capability IE in the SETUP message, the network shall not release the call, but shall reply with one bearer capability IE only, as specified in 3GPP TS 23.172[ Technical realization of Circuit Switched (CS) multimedia service UDI/RDI fallback and service modification; Stage 2 ]  [97]. NOTE: Service change and fallback for UDI/RDI multimedia calls is not supported with Fixed Network User Rate set to 32 kbit/s (see 3GPP TS 23.172[ Technical realization of Circuit Switched (CS) multimedia service UDI/RDI fallback and service modification; Stage 2 ]  [97]). If the MS requested for a multimedia call only, and the network accepts the call, the network shall always include a single multimedia bearer capability IE in the CALL PROCEEDING message. The originating user shall determine (possibly by pre-configuration of the terminal) whether a digital connection is required or if the call will be an analog modem call. If the call is expected to be digital the multimedia bearer capability IE parameter ITC is set to UDI/RDI. In an analog call the multimedia bearer capability IE parameter ITC is set to "3,1 kHz audio ex PLMN". Additionally required modem type is indicated (Other Modem Type = V.34). 5.3.6.2.1.1 Fallback If the network, during the setup of an H.324-call, detects that the transit network or the called end does not support an H.324 call (e.g. because of a failure in the modem handshaking in case of an analogue multimedia call), then the network initiates the in-call modification procedure (see subclause 5.3.4.3) towards the MS to modify the call mode to speech, if the MS had included a speech bearer capability IE in the SETUP message. In case of a UDI/RDI multimedia call with service change and fallback, if the network detects that the called end does not support speech, then it initiates an in-call modification procedure towards the MS to modify the call mode to multimedia, if the first bearer capability IE was for a speech call.