7.8 Subscriber and Equipment Trace
23.1193GPPGateway Location Register (GLR)Release 17Stage 2TS
3G TS29.002 [10] states that subscriber and equipment trace is only available for subscribers within their HPLMN area. If the HLR receives a trace request for a subscriber, and the HLR detects that the subscriber is not in the HPLMN, then the HLR does not forward the trace request to the VPLMN. The trace request never reaches the GLR. Therefore it is concluded that the GLR has no impact on subscriber and equipment trace.