A.1 GLR Concept

23.1213GPPArchitectural requirements for Release 1999Release 1999TS

The benefit of the Gateway Location Register (GLR) is the reduction in signalling traffic between networks. GLR is an optional network element which shall not affect the MAP protocol.

A.1.1 Overview of the GLR Concept

The GLR is a node between the VLR and the HLR, which may be used to optimise the handling of subscriber location data across network boundaries.

In figure A.1, the GLR interacts with HLRa and VLRb for roamers on Network B. The GLR is part of the roaming subscriber’s Home Environment. When a subscriber to HLRa is roaming on Network B the GLR plays the role of an HLR towards VLRb and the role of a VLR towards HLRa. The GLR handles any location change between different VLR service areas in the visited network without involving HLRa.

Figure A.1: GLR Overview

The sequence of events when the subscriber roams to network B is as follows:

– VLRb sends the registration message to HLRa via the GLR, (i.e. HLRa stores the GLR’s SCCP address and the GLR stores VLRb’s SCCP address);

– HLRa returns the subscriber profile data;

– the subscriber profile is stored in the GLR and VLRb.

As the roaming subscriber moves between VLRs in network B, then the GLR is updated, but no message is sent to HLRa, therefore the number of messages between Network A and Network B is reduced. The reduction in signalling traffic is a significant benefit when the two networks are far apart, e.g. between Europe and Japan.

Annex B (informative):
Change History

Version

Date

Information about changes

V1.0.0

June 1999

Creation of document from clause 7 of 23.20

V1.0.1

June 1999

Diagram in subclause 7.9 had not been updated in line with S2-99384 in previous version

V2.0.0

June 1999

Some editorial changes in order to prepare the document for the approval by TSG SA, June 1999 meeting

V. 3.0.0

July 1999

Template changed, clauses and sub-clauses numbering corrected, administrative clauses added.

V.3.1.0

October 1999

Inclusion of all the CRs approved at SA#5

TSG SA#

Spec

Version

CR

Subject/Comment

New Version

SA#6

23.121

3.1.0

042r1

Gateway Location Register

3.2.0

SA#6

23.121

3.1.0

043r1

Clarification of SMS sending in UMTS

3.2.0

SA#6

23.121

3.1.0

044r1

SRNS Relocation for PS domain for the case of RT

3.2.0

SA#6

23.121

3.1.0

045r1

Cell Broadcast System Architecture

3.2.0

SA#6

23.121

3.1.0

046r1

Additional modifications related to UMTS area concept change

3.2.0

SA#6

23.121

3.1.0

047

Correction of criteria for data volume reporting from RNC to SGSN

3.2.0

SA#6

23.121

3.1.0

051

Mobile IP

3.2.0

SA#6

23.121

3.1.0

052

Termination point of the GTP-U tunnel

3.2.0

SA#7

23.121

3.2.0

053r1

Tunnel Endpoint Identifier

3.3.0

SA#7

23.121

3.2.0

054

Inter 3G MSC SRNS relocation

3.3.0

SA#7

23.121

3.2.0

055

Change of the reference point name according to 23.002

3.3.0

SA#7

23.121

3.2.0

056

Deletion of SRNS relocation procedure from 23.121

3.3.0

SA#7

23.121

3.2.0

057r1

Removal of "FFS" items

3.3.0

SA#7

23.121

3.2.0

058

Removal of L3CE references

3.3.0

SA#7

23.121

3.2.0

059

Removal of detailed text on handover

3.3.0

SA#9

23.121

3.3.0

062r2

Correction to data Retrieve protocol Stacks end points

3.4.0

SA#10

23.121

3.4.0

063

Removal of Combined update towards the HLR for a combined 3G (MSC/VLR + SGSN) configuration

3.5.0

23.121

3.5.0

Resolution of a problem with MS Word automatic header numbering

3.5.1

SA#16

23.121

3.5.1

064r2

CS domain signalling requirements: MSC and RNC behaviour relating to handover and cell reselection

3.6.0

  1. GTP-u stands for GTP user plane protocol

  2. Note that in this text, Mobile IP is used in a wide sense. It refers to [10] and the RFC’s planed to be finalized this year.