| 摘要 |
PROBLEM TO BE SOLVED: To understand the position of a stolen vehicle in a relatively narrow range without using any sensor. SOLUTION: A user starts a terminal 10 when he leaves a vehicle, the terminal 10 periodically receives the radio wave of a plurality of PHS base stations, detects a plurality of top class base stations ID whose reception level is high (3), stores the detected value in a storage part 4 for the first time, writes it in a storage part 5 of the second and subsequent times, compares ID of the storage parts 4, 5 with each other for each ID detection (7), repeats the ID detection if any one is agreed. If no ID is agreed at all through the movement of the vehicle, the automatic transmission is made to a terminal 20 at his own house, etc., through the PHS, the voice alarm data is transmitted, and then, the detected ID is transmitted, and the terminal 20 obtains the map information of the ID from a map storage part 12 by the PHS cell unit, and indicates it on an indication part 13. Then, the maximum ID of the reception level is repeatedly transmitted to the terminal 20. |
