GSM 09.02 - Version 5.3.0 - Digital cellular telecommunications - ETSI

17.2.1 Procedures in the HLR
17.2.1.1 Subscriber tracing activation procedure
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GSM 09.02 Version 5.3.0: August 1996
When receiving the subscriber tracing mode activation command for a subscriber from the OMC, the HLR
will activate tracing, if the subscriber is known and registered in the HLR and the subscriber is roaming in
the home PLMN area. The MAP_ACTIVATE_TRACE_MODE request is sent to the VLR where the
subscriber is registered.
If the MAP_ACTIVATE_TRACE_MODE confirmation is received indicating an error situation, the errors are
mapped to the OMC interface. The activation request may also be repeated; the number of repeat
attempts and the time in between are HLR operator options, depending on the error returned by the VLR.
If the subscriber is known in the HLR, but is deregistered or roaming outside the home PLMN area, the
subscriber tracing status is activated in the HLR, but the VLR is not updated.
When receiving a request for location updating or data restoration while the subscriber trace mode is
active, the macro Control_Tracing_HLR (see figure 21.9/4) shall be initiated by the location updating
process in the HLR.
The subscriber tracing activation process in the HLR is shown in figure 17.2/7.