23.0783GPPCustomised Applications for Mobile network Enhanced Logic (CAMEL) Phase 4Release 17Stage 2TS
6.2.1 Definition and description
GPRS events may be made visible to the gsmSCF. The DPs are the points in association at which these events are detected. The DPs for GPRS Session and PDP Context are described in subclause 6.4.2 and subclause 6.4.3.
A DP can be armed in order to notify the gsmSCF that the GPRS event was encountered, and to allow the gsmSCF to influence subsequent handling of the GPRS Session, or the PDP Context. If the DP is not armed, the processing entity continues the processing without gsmSCF involvement at this DP.
Three different types of DPs are identified:
– Trigger Detection Point-Request (TDP‑R): This detection point is statically armed and may initiate a CAMEL control relationship. This CAMEL control relationship is within a new GPRS dialogue. When the GPRS event is encountered and reported, processing is suspended.
– Event Detection Point- Request (EDP‑R): This detection point is dynamically armed within the context of a CAMEL control relationship. When the GPRS event is encountered, and reported, processing is suspended and the gprsSSF waits for instructions from the gsmSCF.
– Event Detection Point-Notification (EDP‑N): This detection point is dynamically armed within the context of a CAMEL control relationship. When the GPRS event is encountered and reported, processing is not suspended.
A DP may be statically armed or dynamically armed. The following arming rules apply:
– DPs for GPRS Session and PDP Context are statically armed as a result of the GPRS‑CSI analysis in the SGSN.
– DPs may be dynamically armed by the gsmSCF within the context of a CAMEL control relationship. In scenario 1 which is described in the subclause 22.214.171.124, PDP context related DPs may be armed as generic DP or as non-generic DP.
The following disarming rules apply:
– A statically armed DP is disarmed when the GPRS‑CSI is withdrawn in the HLR. Only TDP‑Rs can be disarmed using this mechanism.
– If the GPRS Session is released, then all EDPs related to the GPRS Session are disarmed.
– If a PDP context is released, then all non-generically armed EDPs related to that PDP context are disarmed.
– If a non-generically armed EDP is met, then EDPs for the GPRS Session or that PDP Context are disarmed, in accordance with the implicit disarming rule (see subclause 6.4.6).
– Armed EDPs may be explicitly disarmed by the gsmSCF by means of the Request Report BCSM Event information flow.
6.2.2 Relationship, DP processing rules and GPRS dialogue
A relationship between the State Models (in the gprsSSF) and the gsmSCF for the purpose of operator specific service processing is considered to be a CAMEL relationship. There are two types of CAMEL relationships: monitor relationship and control relationship.
– A CAMEL control relationship: the gsmSCF is able to influence the GPRS Session/PDP Context via the relationship for the given state model.
– A CAMEL monitor relationship: the gsmSCF is not able to influence the GPRS Session/PDP Context via the relationship for the given state model.
A control relationship persists as long as there is one or more EDP‑R armed for this instance of the state model, or if the gprsSSF is in the state Waiting For Instruction for this instance of state model.
A control relationship changes to a monitor relationship if the conditions for a control relationship are no longer fulfilled and one or more EDP‑N is armed or one or more Apply Charging Report GPRS is outstanding for this instance of the state model. If no EDP‑Ns are armed and no Apply Charging Reports GPRS are outstanding for this instance of the state model, the relationship terminates.
A GPRS dialogue exists between gprsSSF and gsmSCF if at least one of the following conditions is fulfilled:
– There is at least one EDP armed,
– At least one report is pending,
– gprsSSF is in state Waiting_For_Instructions.