5 Roaming Scenario

23.1193GPPGateway Location Register (GLR)Release 17Stage 2TS

Figure 1 shows that the GLR is deployed at the edge of visited network. It contains roamer’s subscriber profile and location information, and handles mobility management within the visited network.

The subscriber information is downloaded from HLR to GLR at the first location update procedure under the GLR. Using the information, GLR handles Update Location message from VLR as if it is the HLR of the subscriber at second and further location updating procedures. GLR enables the procedure invisible from the home network so that this hierarchical location management can reduce the inter-network signalling for the location management.

The GLR keeps the information until receiving Cancel Location message from HLR.

5.1 Relationship between GLR and HLR

A GLR interacts with multiple HLRs, which will be located in different PLMNs. The relationship between the GLR and the HLR is the same as that between the VLR and the HLR.

The implication of supporting multiple HPLMNs is that the GLR will need to store a large amount of profile data.

5.2 Relationship between GLR and VLR

A GLR interacts with multiple VLRs. For the purposes of this Technical Specification, the GLR supports only one VPLMN. The support of multiple VPLMNs by the GLR is outside the scope of this Technical Specification.

However, it is an assumption of this specification that the proposed GLR architecture must not prevent future expansion to support multiple VPLMNs.

Figure 5.2/1: Possible Location of GLR

5.3 Roaming to VPLMN with GLR from HPLMN without GLR

Figure 5.3/1 shows the roaming scenario in case of a subscriber roaming to a new VPLMN with the GLR.

Figure 5.3/1: Roaming to VPLMN with the GLR from HPLMN without the GLR

5.4 Intra-VPLMN with GLR roaming

In this case, the second and further location updating procedure is handled within the VPLMN. No location management message issent to the HPLMN.

Figure 5.4/1: Intra-VPLMN with GLR roaming

5.5 Inter-VPLMNs with GLR Roaming

This roaming case is similar to the case of roaming from HPLMN to VPLMN. The first location update procedure is handle by HLR and VLR via GLR of a new VPLMN.

Figure 5.5/1: Inter-VPLMN with GLR roaming

5.6 Roaming to VPLMN without GLR from VPLMN with GLR

In this case the cancel location procedure is handled by HLR and VLR via GLR of old VPLMN.

Figure 5.6/1: Roaming to VPLMN without GLR from VPLMN with GLR