UMTS will build on the success of GSM and is likely to become even more widespread. IMT-2000 networks based on GSM evolution are planned for Europe, Japan, USA and Korea. Coupled with steadily increasing rates of international travel for business and leisure, this means a significant increase in the number of roaming users needing to be supported. This will lead to increased signalling traffic on "short -haul" and "long-haul" international links. The introduction of CAMEL Phase 3 for UMTS will add CAP signalling to these international links, leading to a further signalling load increase over present day levels.
The GLR (Gateway Location Register) is a node between the VLR and the HLR, which may be used to optimise the handling of subscriber profile data across network boundaries. The GLR is functionally part of the roaming subscriber's Home Environment. When a subscriber is roaming the GLR plays the role of the HLR towards the VLR in the visited network, and the role of the VLR towards the HLR in the home network. The GLR handles any location change between different VLR service areas in the visited network without involving the HLR. The GLR is an optional entity within the VPLMN operator's network.
This TR describes the use of a Gateway Location Register within the UMTS Core Network as a means of reducing the amount of MAP signalling traffic associated with location management carried over inter-PLMN links for roaming users.
One of the requirements of the present document is to describe a network architecture where the presence of a GLR
within a UMTS PLMN is not visible to either a second generation PLMN (i.e. GSM release 98 or earlier) or a 3G
PLMN (i.e. GSM Release 99 or later). So the objective of this report is that changes to GSM specified interfaces or
procedures will not be needed in order to:
integrate a GLR into a UMTS PLMN;
allow interworking between a GLR-enabled UMTS network and a GSM or UMTS network without a GLR.
The present document will be restricted to the study of the case where the GLR supports one VPLMN only. A separate
TR will be required if support of multiple VPLMNs by the GLR is to be studied.
The present document will study support of multiple HPLMNs by the GLR.
full Table of Contents for TR 23.909 Word version: 4.0.0