A method to perform subsidy protection for tdma mobile stations

摘要

A method of activating a mobile station used in a cellular network system provides subsidy protection for a cellular operator. The method comprises the steps of installing a subscriber identity module (SIM) in the mobile station, the SIM having an IMSI file and storing the first indicia uniquely identifying the cellular operator, the mobile station storing second indicia uniquely identifying the cellular operator; comparing the first indicia to the second indicia to determine if the SIM and the mobile station are valid for the cellular operator; and if the SIM and the mobile station are valid, then storing a mobile identity number in the IMSI file of the SIM.