4.3.7 Interactions with CAMEL

23.1723GPPRelease 17Stage 2Technical realization of Circuit Switched (CS) multimedia service UDI/RDI fallback and service modificationTS

4.3.7.1 Interaction at call setup

When a SCUDIF call activates a CAMEL dialogue for the originating or the terminating subscriber, both basic services shall be indicated to the gsmSCF in the InitialDP message (see 3GPP TS 23.078 [14]) :

– the bearer capability IE and the ext-basic service code IE shall indicate the preferred service (i.e. 3G-324.M if the 3G-324.M codec is the first codec in the list of supported codecs ; speech otherwise),

– the bearer capability 2 IE and the ext-basic service code 2 IE shall indicate the other, less preferred service (i.e. resp. speech or 3G-324.M).

4.3.7.2 Interaction at call answer

When the Answer DP is triggered according to the BCSM (see 3GPP TS 23.078 [14]), the event report sent to the gsmSCF shall indicate the result from the OoBTC codec negotiation procedure according to the following :

– the ext-basic service code IE is included, and represents the selected service (indicated by the selected codec) ;

– the ext-basic service code 2 IE is included if the list of available codecs contains codecs both for speech and 3G-324.M, and represents the other service (i.e. speech if the selected service is 3G-324.M, and vice-versa).

4.3.7.3 Interaction with Call Party Handling

Interaction with Call Party Handling is allowed, when the call is a speech call and it cannot become a multimedia call.

See 3GPP TS 22.078 [16] clause 21.

4.3.7.4 Interaction with CAMEL in-band information and user interaction

Interaction with Camel in-band information and user interaction is allowed, when the call is a speech call and it cannot become a multimedia call.

See 3GPP TS 22.078 [16] clause 21.

4.3.7.5 Interaction during service change

When a service change is successfully completed (i.e. the codec modification or mid-call codec negotiation reply message indicates a successful codec modification), and the O_Service_Change DP or the T_Service_Change DP is armed, then the relevant detection point is triggered (see 3GPP TS 23.078 [14]).

When a service change is rejected (i.e. the codec modification or mid-call codec negotiation reply message indicates a failure), then the previously selected service is kept, and no event report shall be sent to the gsmSCF for the O_Service_Change DP and the T_Service_Change DP.