The Local Mobile Station Identity (LMSI) is a temporary identifier assigned to a mobile station when it roams into a different network. This is useful when the roaming telephone number (MSRN) is assigned on a per-call basis, helping expedite subscriber data retrieval in the visitor’s location register (VLR). The VLR assigns the LMSI during location updates and sends it, along with the subscriber identity (IMSI), to the home location register (HLR). While the HLR retains the LMSI, it includes both the LMSI and IMSI in all messages sent to the VLR regarding that mobile station.