| 摘要 |
PROBLEM TO BE SOLVED: To enable a telephone user himself to surely execute charging of a telephone charge. SOLUTION: A prepaid card reading part 30 is fixed to a conventional portable telephone set for rewriting the frequency information of a prepaid card housed in the part 30 each time a charging signal from an exchange 60 is received. In addition, a radio telephone network is constituted through the use of a GPS satellite 50 to communicate between portable telephone sets 10. |
