Patent ID: 8442487

Claim:
A method, comprising: detecting a change of a location area code for a mobile station operating in a mobile communication system, where location area codes for a plurality of mobile stations operating in a plurality of location areas are stored in a register of the mobile communication system that also stores subscriber data pertaining to the plurality of mobile stations; determining if the change in the location area code is a result of an occurrence of an event that is not expected to trigger a change in a location area code because the event is of such a nature that a valid event of that nature will have been preceded by a location area code change, and thus no location area code change would be expected to accompany the event, wherein the determining comprises examining an event type identifier to determine if the event type identifier indicates that the event is of a type that is not expected to trigger a change in a location area code; and if the event type identifier indicates that the event is not expected to trigger a change in a location area code, generating a message and transmitting the message to inform an operator of the mobile communication system that the mobile station has the same mobile station identity as another mobile station.