5 Routeing of a call from a subscriber served by the HPLMN

03.043GPPSignalling Requirements Relating to Routing of Calls to Mobile SubscribersTS

If the calling subscriber is served by an exchange which is part of the HPLMN, the configuration is as shown in figure 1. The originating MSC is able to interrogate the HLR for an MSRN, and the call is routed within the PLMN. If the called MS has roamed to another PLMN the originating MSC routes the call to the visited PLMN (VPLMN) as shown in figureĀ 2.

Figure 1: Call from a subscriber in the HPLMN of the called MS

Figure 2: Call from a subscriber in the HPLMN of the called MS; called MS roamed to another PLMN