GSM 09.02 - Version 5.3.0 - Digital cellular telecommunications - ETSI

Page 364
GSM 09.02 Version 5.3.0: August 1996
If the VLR serves more than one MSC, the indicator "Location Information Confirmed in HLR" is used in the
VLR restoration procedure as well as in the HLR restoration procedure. When an IMSI record is created in
the VLR, the indicator must be set to "Not Confirmed".
VLR restoration triggered by a location registration request
Upon receipt of a MAP_UPDATE_LOCATION_AREA indication, the VLR retrieves authentication data from
the HLR by using the MAP_SEND_AUTHENTICATION_INFO service if authentication is required and if no
authentication data are available in the VLR for the IMSI concerned (see figure 16.1.1/6).
Receipt of a MAP_UPDATE_LOCATION_AREA indication for an MS whose IMSI is unknown in the VLR or
whose data stored in the VLR are marked as "Not Confirmed" by the indicator "Confirmed by HLR" and/or
by the indicator "Location Information Confirmed in HLR" forces the VLR to invoke the
MAP_UPDATE_LOCATION service after successful authentication, if required. The location updating
procedure is performed as described in subclause 16.1.
Any other mobile originated request from an MS whose IMSI is unknown in the VLR or whose subscriber
data stored in the VLR are marked as "Not Confirmed" by the indicator "Confirmed by HLR" shall be
rejected with error cause "Unidentified Subscriber". This causes the MS to trigger the location registration
procedure.
After successful completion of the MAP_UPDATE_LOCATION procedure, the indicators "Confirmed by
HLR" and "Location Information Confirmed in HLR" are set to "Confirmed".
The indicator "Confirmed by Radio Contact" is set to "Confirmed" when the radio contact with the MS is
authenticated.
VLR restoration triggered by a roaming number request
Figure 16.3/1 illustrates the signalling sequence for restoration of an IMSI record in the VLR triggered by a
mobile terminating call set-up.
Upon receipt of a MAP_PROVIDE_ROAMING_NUMBER indication for an IMSI that is unknown in the VLR
and for which authentication is required, the VLR retrieves authentication data from the HLR by using the
MAP_SEND_AUTHENTICATION_INFO service after an MSRN has been sent to the HLR in the
MAP_PROVIDE_ROAMING_NUMBER response.
Receipt of a MAP_PROVIDE_ROAMING_NUMBER indication for an MS whose IMSI is unknown in the
VLR or whose data record in the VLR is marked as "Not Confirmed" by the indicator "Confirmed by HLR"
forces the VLR to request subscriber data from the HLR by sending a MAP_RESTORE_DATA request
which triggers one or more INSERT_SUBSCRIBER_DATA operations from the HLR. The
MAP_RESTORE_DATA request may also be used to send the LMSI to the HLR.
The MAP_RESTORE_DATA process in the VLR is described in subclause 18.2.4.
The MAP_RESTORE_DATA process in the HLR is described in subclause 16.3.3.
After successful completion of the MAP_RESTORE_DATA procedure, the indicator "Confirmed by HLR" is
set to "Confirmed".
If restoration of an IMSI record was triggered by a MAP_PROVIDE_ROAMING_NUMBER indication
(i.e. by a mobile terminating call), the VLR has no valid Location Area Identity information for the MS
concerned before successful establishment of the first authenticated radio contact. Upon receipt of a
MAP_SEND_INFO_FOR_INCOMING_CALL indication from the MSC (see 5 in figure 16.3/1) for an MS
whose subscriber data are marked as "Confirmed" by the indicator "Confirmed by HLR" but not confirmed
by radio contact, the VLR shall invoke a "MAP_SEARCH_FOR_MS" instead of a "MAP_PAGE".