TMSI

The Temporary Mobile Subscriber Identity (TMSI) is a temporary identification number that is used in the GSM network instead of the IMSI to ensure the privacy of the mobile subscriber. The TMSI prohibits tracing of the identity of a mobile subscriber by interception of the traffic on the radio link.

The TMSI is assigned to a mobile subscriber by the Authentication Centre (AUC). The TMSI is assigned for the duration that the subscriber is in the service area of the associated Mobile Switching Centre (MSC).