22.0783GPPCustomised Applications for Mobile network Enhanced Logic (CAMEL)Release 17Service descriptionStage 1TS
B.2.1 Initial contact with the CSE
When the IM CN subsystem initiates contact with the CSE, the IPMM session processing is suspended and the IM CN subsystem waits for instructions from the CSE. It shall be possible to specify which of the following initial events shall initiate contact with the CSE:
- Called identity received at the IM CN subsystem,
- Analysis of called identity
- Unsuccessful IPMM session setup.
After initial contact with the CSE, the CSE shall provide the IM CN subsystem with further instructions as detailed in table C-1.
B.2.2 Criteria for initial contact with the CSE
B.2.2.1 CSI criteria applicable at IPMM session setup when called identity is received
CSI criteria may be defined for a subscriber for the case when the called identity is received at IPMM session setup .
– Criteria on the called identity; these consist of:
– The contents of the identity (a list of up to 10 identities may be defined in the criteria)
- The criteria on the called identity may be collectively defined to be either "enabling" triggering criteria or "inhibiting" triggering criteria (see below). The HPLMN may also choose not to define any criteria on the called identity.
B.2.2.2 CSI criteria applicable at IPMM session setup after analysis of called identity
A CSI criterion on the contents of the called identity shall be defined for subscribed dialled services. A list of up to 10 called identities may be defined in the criterion. Each entry in the called identity list has associated with it a CSE identity and a service key which defines the service to be triggered if the criterion is satisfied.
If any other CAMEL dialogue has changed the called number, then the modified called identity shall be used for the conditional triggering check.
The called identity criterion is satisfied if the called identity matches a called identity string defined in the criterion.
The Enhanced dialled services is not applicable for the IMS.
B.2.2.3 CSI criterion applicable on detection of unsuccessful IPMM session establishment
A criterion on the release cause may be defined. This may consist of a list of up to 5 cause values. The criterion on the release cause is satisfied if the received call release cause corresponds to any cause value defined in the list or if no criterion is defined.
B.2.3 Subsequent events reported to the CSE
After initial contact with the CSE, the CSE may request the IM CN subsystem to detect and report subsequent events. These events are listed below. With each of these events, the CSE shall indicate the type of monitoring (ie suspension of IPMM session processing or notification). If the CSE requests the suspension of IPMM session processing, it shall provide the IM CN subsystem with further instructions as detailed in table C-1.
The subsequent events that may be detected by the IM CN subsystem and reported to the CSE are:
– The called party answers;
– Additional information received from the originating party;
– TheIPMM session is disconnected;
– The originating party abandons the IPMM session;
– Unsuccessful IPMM session setup. The following events shall be possible:
– The called party is busy;
- The called party does not respond in specified time period;
- The called party can not be reached.
B.2.4 Instruction by the CSE
After initial contact with the CSE, or after the reporting of subsequent events to the CSE, the CSE shall be able to instruct the IM CN subsystem with the following;
- To bar the IPMM session;
- To arm one or more subsequent events;
- To perform the charging activity;
- To perform the in-band user interaction;
- To continue the IPMM session;
- To continue the IPMM session with modified information;
- To release the IPMM session.
The combination of the event reported to the CSE and the instruction by the CSE is provided in the table C-1. Table C-1 Actions performed by the CSE at specific service event for MO and MT IP multimedia session can be found in Annex C.
B.2.5 IM Application Level Registration procedure
When a user registers on application level with the IM CN subsystem, initial trigger information shall be provided to the IM CN subsystem. Initial trigger information shall be sufficient to enable the IM CN subsystem to detect relevant IPMM sessions and to contact the proper CSE.
The set of information shall at least include the CSE identity to be contacted, the user for which it is valid, the originating and terminating initial event including specific criteria if needed and the service key for the CSE service subscribed to. The initial trigger information for IM CN subsystem shall contain information for the IM CN subsystem only.