03.793GPPStage 2Support of Optimal Routeing phase 1TS
A subscriber: The calling subscriber, who may be fixed or mobile.
B subscriber: The mobile subscriber originally called by the A subscriber.
C subscriber: The subscriber to whom the B subscriber has requested that calls be forwarded. The C subscriber may be fixed or mobile.
Direct route: A call takes the direct route if the route from the serving PLMN of the A subscriber to the serving PLMN of the B subscriber is defined by the MSRN of the B subscriber rather than by the MSISDN of the B subscriber.
Early call forwarding: call forwarding from the IPLMN before the call has been extended to the VPLMN of the forwarding subscriber.
HPLMN leg: The portion of the HPLMN route from the serving MSC of the A subscriber to an MSC in the HPLMN of the B subscriber.
HPLMN route: A call takes the HPLMN route if the route from the serving MSC of the A subscriber to the serving MSC of the B subscriber is defined by the MSISDN of the called subscriber. This forces the call to be routed via the HPLMN of the B subscriber.
Interrogating PLMN (IPLMN): The PLMN which interrogates the HPLMN of the B subscriber to obtain information to route the call to that subscriber or to the forwarded-to destination defined by the called mobile subscriber. The IPLMN is also the VPLMN of the A subscriber.
Late call forwarding: call forwarding after the call has been extended to the VPLMN of the forwarding subscriber. Late call forwarding may be invoked in the IPLMN or the VPLMN of the forwarding subscriber.
Reference address: The address which defines the maximum charge which the A party is prepared to pay for the call leg which he originates.
Routeing address: The address which the GMSC uses to route a call towards the B subscriber or the C subscriber.
Abbreviations used in the present document are listed in GSM 01.04 .
For the purposes of the present document, the following abbreviations apply:
BOIZC Barring of Outgoing InterZonal Calls
BOIZC-exHC Barring of Outgoing InterZonal Calls except those directed to the HPLMN Country
CMN CAMEL Modified Number
FTN Forwarded-To Number
FTNW Forwarded-To NetWork
GMSCA The GMSC in the IPLMN, which may also be VMSCA
GMSCB The GMSC in HPLMNB
GMSCC The GMSC in HPLMNC
HLRB The HLR of the B subscriber
HLRC The HLR of the C subscriber
HPLMNB The HPLMN of the B subscriber
HPLMNC The HPLMN of the C subscriber
IAM Initial Address Message
IPLMN Interrogating PLMN
ORLCF Optimal Routeing for Late Call Forwarding
PRN Provide Roaming Number
PSI Provide Subscriber Information
RCH Resume Call Handling
SIFIC Send Information For Incoming Call
SIFOC Send Information For Outgoing Call
SRI(B) Send Routeing Information (Basic call)
SRI(F) Send Routeing Information (Forwarding information)
VLRA The VLR of the A subscriber
VLRB The VLR of the B subscriber
VMSCA The VMSC of the A subscriber
VMSCB The VMSC of the B subscriber