12.053GPPSubscriber Related Call and Event DataTS
Figure B.6 illustrates an incoming call from a fixed network subscriber "A" to a mobile subscriber "B" who has registered and activated Call Forwarding Unconditional (CFU) for the appropriate service. The call is subsequently forwarded to a second fixed network subscriber "C".
For simplicity the registration and activation of CFU have not been included in the diagram. These actions shall of course be recorded in the appropriate supplementary service records.
The incoming call is routed to a GMSC (1). This part of the connection is identical to the scenario outlined in subclause B.4.2.
The GMSC interrogates the HLR of the called subscriber in order to determine his current location (2). The HLR shall create an HLR interrogation event record. The HLR informs the GMSC that "B" has activated CFU to subscriber "C".
The GMSC forwards the call to the fixed network subscriber "C" (3). The GMSC shall create 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". Both records shall contain the supplementary service employed (CFU). The GMSC shall also produce an outgoing gateway record as described in subclause B.4.1.
The records generated are subsequently transferred to the OS of the HPLMN (A).
Figure B.6: Call forwarding unconditional