B.4.13 Incoming call handled by CAMEL with redirection decided and forwarding leg handled by CAMEL

12.053GPPSubscriber Related Call and Event DataTS

Figure B.13 illustrates an incoming call from a fixed network subscriber "A" to a mobile CAMEL subscriber "B". The call is subsequently forwarded to a second fixed network subscriber "C" by CAMEL initiated Call Forwarding.

The incoming call is 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 and O-CSI (2).

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.

The gsmSCF modifies the Called Party number and sets the CAP parameter ‘Apply O-CSI’. 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 "B" subscriber has an active O-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 (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 GMSC

The GMSC redirects the call to the fixed network subscriber "C" (5). The GMSC shall generate an MTC record for the "B" subscriber for the call from "A" and an MOC (call forwarding) record for the "B" subscriber for the call to "C". The MOC record includes O-CSI data and the parameter ‘CAMEL initiated CF indicator’. The GMSC shall also produce an outgoing gateway record as described in subclause B.4.1.

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

HLR

Incoming gateway record

HLR interrogation record

Terminating CAMEL int. record

MTC record

MOC (CF) record

Outgoing gateway record

Figure B.13: Incoming call handled by CAMEL with redirection decided and forwarding leg handled by CAMEL