| 摘要 |
PROBLEM TO BE SOLVED: To transfer and to save information (SIN information) concerning an updated and changed subscriber in a memory in a SIM card when abnormaliby occurs in the power source voltage of a mobile telephone set. SOLUTION: When the SIM card 2 is mounted and use the mobile telephone set 1, SIM information is read from the SIM card 2 and transferred and stored into the memory 47 of the telephone set 1 and SIM information which is added and updated under the operation of the telephone set is transferred and saved into a SIM memory 8 when the usage of the telephone set 1 is completed in the termination processing circuit of the mobile telephone set 1. Communication with the SIM card 2 and storing work to the SIM memory 8 are executed by SUB-CPU 30 which is backed-up by the power source 34 different from a mainbody power source 3 in order to permit SIM information stored in the memory 47 in the telephone set to be normally rewritten in the SIM memory 8 even if the operation of a main processor 9 in the telephone set 1 is stopped by a voltage fluctuation and a drop or disconnection by carelessness in the power source 3 under the usage of the mobile telephone set 1. |
