| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an authentication system which carries out authentication between a control device and an authentication medium held by the user of the control device by radio communication, wherein the authentication system is proof against influence of elements for blocking the radio communication such as disturbing radio waves, and achieves normal operation of an object to be controlled. <P>SOLUTION: According to the authentication system, the smart security control device 5 transmits a designation requiring signal for designating a responding frequency, to a portable machine 3. If any signal cannot be received by radio within an allowable time set beforehand after transmission of the designation requiring signal, a designation requiring signal for designating a changed responding frequency is transmitted. Then the portable machine 3 selects the responding frequency designated by the designation requiring signal, and transmits a reception responding signal at the selected responding frequency to the smart security control device 5. Therefore an incapability of reception of a response signal caused by radio interference of the response signal can be avoided. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
