Patent ID: 6119020
Filing Date: 2000-09-12
Classification: H04B,H04M,H04W

Abstract:
A method of operating a subscriber unit having a SIM card reader, said method comprising the steps of:reading a first preprogrammed signature value from a primary SIM card;comparing said first preprogrammed signature value to a preprogrammed signature value stored in said subscriber unit, said preprogrammed signature value being singularly unique to said subscriber unit;enabling communications functions of said subscriber unit only if said first preprogrammed signature value read from said primary SIM card corresponds to said first preprogrammed signature value stored in said subscriber unit;requiring a user to enter a password;comparing said user entered password with one or more passwords stored in said subscriber unit, said password stored in said subscriber unit being uniquely assigned to said primary SIM card; andpermitting entry of additional signature values of one or more additional authorized SIM cards only if said user entered password corresponds to one of said stored passwords.