B.4.19 Incoming call handled by CAMEL in VMSC without redirection

32.0053G call and event data for the Circuit Switched (CS) domain3GPPCharging managementRelease 1999Telecommunications managementTS

Figure B.19 illustrates an incoming call from a fixed network subscriber "A" to a mobile CAMEL subscriber "B".

The incoming call is first routed to the GMSC (1). The GMSC shall create an incoming gateway record for fixed network accounting purposes.

The GMSC interrogates the HLR (2) of the called subscriber. The HLR shall create an HLR interrogation record. The call is routed to MSC-B(3). An MTC record shall be generated.

The "B" subscriber has an active VT-CSI (stored in the VLR). Therefore MSC-B requests instructions from the gsmSSF which passes the CAMEL service key to the gsmSCF to indicate which service logic it should apply (4).

The gsmSCF may interrogate the HLR for subscriber information. As a network option, the operator may refuse to provide the requested information.

When gsmSCF processing is complete the call control is returned to the MSC-B. The MSC-B shall generate a terminating CAMEL (TCR) record which contains VT-CSI data.

The MSC-B routes the call to the "B" subscriber (5).

For avoidance of doubt, even if the MSC and GMSC are co-located both the MTC/TCR and gateway records shall be produced.

The generated records are subsequently transferred to the OS (A) either as event reports following the release of the connection or when collected by the OS.

The following records are generated in HPLMN in this call scenario:

GMSC

MSC-B

HLR

Incoming gateway record

MTC record

HLR interrogation record

Terminating CAMEL record

Figure B.19: Incoming call handled by CAMEL in VMSC without redirection