12.053GPPSubscriber Related Call and Event DataTS
Figure B.11 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 of the called subscriber in order to fetch the T-CSI (2). The HLR shall create an HLR interrogation record.
The "B" subscriber has an active T-CSI. Therefore the GMSC requests instructions from the gsmSSF which passes the CAMEL service key to a gsmSCF to indicate which service logic it should apply (3).
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 GMSC. The GMSC shall generate a terminating CAMEL interrogation record which contains T-CSI data.
The GMSC interrogates the HLR in order to determine his current location (4). The HLR shall create an HLR interrogation record.
The call is routed to MSC-B (5). An MTC record shall be generated.
For avoidance of doubt, even if the MSC and GMSC are co-located both the MTC 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:
Incoming gateway record
HLR interrogation record
Terminating CAMEL int. record
Figure B.11: Incoming call handled by CAMEL without redirection