| 摘要 |
PROBLEM TO BE SOLVED: To accurately inform a user of a radio terminal mounted on a vehicle that the reception sensitivity of the radio terminal becomes worse owing to an environment outside the vehicle in such a case. SOLUTION: A control unit 2 in a car navigation device 1 detects the reception sensitivity of a mobile phone 10 and when the detected reception sensitivity is lower than a previously set reference level, the control unit stores the current travel area of the vehicle as a deficient reception sensitivity area in a reception state history database in sequence and also displays the deficient reception sensitivity area which is thus stored in the top layer of a map picture displayed on a display device 5a. Further, the control unit 2 initializes the stored data when the vehicle travels in an area wherein the reception sensitivity of the mobile phone 10 is equal to or higher than the previously set reference level and the area is stored as deficient reception sensitivity area data in the reception state history database. COPYRIGHT: (C)2007,JPO&INPIT |
