摘要 |
A method for the recognition of the proximity of a portable transponder ( 20 ) to a base station ( 2 ), comprises the steps of: the base station transmits a first test signal with a defined power, the transponder determines the field strength with which it received the first test signal, and transmits a response signal to the base station containing said field strength and the base station stores the same. The transponder transmits a second test signal with a defined power, the base station determines the field strength with which it receives the second test signal and determines, from a comparison of the two field strengths, whether the transponder is in the vicinity thereof.
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