| 摘要 |
<P>PROBLEM TO BE SOLVED: To confirm whether or not a frequency used at present for in-vehicle wireless communication is a frequency proper to prevent leakage of a radio wave from all the open frames of a vehicle. <P>SOLUTION: The apparatus of this invention acquires: an environmental change in the case of making in-vehicle wireless communication by a radio wave with a transmission frequency lower than the cut-off frequency of a waveguide to which the open frames, existing in the vehicle body of the vehicle and permitting passing of a radio wave between the inside and the outside of the vehicle body, compare while preventing leakage of the radio wave from the open frames to the outside of the vehicle body; and is characterized in including: an opening / closing state detection means A provided to the vehicle body and for detecting an opening / closing state of opening / closing bodies acting like the open frames in the case of opening and acting like parts of the vehicle body in the case of closing; and a new open frame production discriminating means B for discriminating the presence / absence of a new open frame on the vehicle body in the case that the cut-off frequency at time of selecting it as waveguide, to which the new open frame compares, is lower than the present transmission frequency of the radio wave on the basis of the detection result by the opening / closing state detection means A. <P>COPYRIGHT: (C)2004,JPO |
