4 Introduction

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

UMTS will build on the success of GSM and is likely to become even more widespread. UMTS/ 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 an increase of the signalling traffic on "short -haul" and "long-haul" international links.

The GLR (Gateway Location Register) is a node between the VLR and/or SGSN and the HLR, which may be used to optimise the location updating and the handling of subscriber profile data across network boundaries. When a subscriber is roaming the GLR plays the role of the HLR towards the VLR and SGSN in the visited network and the role of the VLR and SGSN towards the HLR in the home network.

The GLR is an optional entity within the VPLMN. The network architecture where the presence of a GLR within a UMTS PLMN is not visible to either a second generation HPLMN (i.e. GSM release 98 or earlier) or a 3G HPLMN (i.e. GSM Release 99 or later).