GLR Gateway Location Register
The GLR (Gateway Location Register) is a node between the VLR (visitor Location Register) and/or SGSN (Serving GPRS Support Node) and the HLR (Home Location Register), 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.
