| 摘要 |
PROBLEM TO BE SOLVED: To prevent illegal electric waves from being radiated by automatically judging whether or not the electric waves are within the communication frequencies allowed to use. SOLUTION: A radio communication circuit 2 is set to f1 to f2 in its usable frequency. A control device 1 makes a position on a map correspond to the current position using the map data 5 on the basis of the current position information detected by a position detector 3, reads a frequency usable at that position from a position-frequency correspondence table 6. Further, the control device switches the frequency to the usable communication frequency of the radio communication circuit 2 and sets the latter frequency provided that the former frequency can be dealt with by the latter frequency, while the control device sets the operation to transmission prohibition when the former frequency can not be dealt with. COPYRIGHT: (C)2005,JPO&NCIPI
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