INTERWORKING LOCATION REGISTER (ILR)

ILR FUNCTIONS

ILR offers roaming capabilities between mobile telephony systems complying with different standards. The ILR is specific to the GSM1900 product portfolio and enables AMPS network subscribers to roam to a GSM 1900 network. In the near future the ILR will make intersystem roaming possible both directions between all GSM, AMPS/TDMA networks. For AMPS subscribers who wish to avail of this roaming functionality, their AMPS network subscriptions are copied into the HLR side of the ILR. When they roam into the GSM 1900 network, the HLR copies this information into the VLR side of the ILR, as occurs for normal GSM roaming subscribers. From the subscriber’s point of view however, there is only one subscription. In the near future, the ILR will make intersystem roaming possible in both directions between all GSM, AMPS/TDMAnetworks

ILR IMPLEMENTATION

In some GSM systems the ILR is AXE-based. It includes the common APZ and APT subsystems outlined previously and the following additional subsystems:

ILR subsystems

ILR hardware is similar to HLR hardware.