| 摘要 |
PROBLEM TO BE SOLVED: To make acquirable accurate present position information when a vehicle reaches the vicinity of a crossing, while reducing the communication cost, concerning an on-vehicle radio communication device. SOLUTION: This device is equipped with a distance sensor 19b for measuring a mileage of the driver's own car, and an operation processing part 20. The operation processing part 20 determines whether the distance from the driver's own car position to the next guide crossing is below a prescribed distance or not based on the mileage measured by the distance sensor 19b and received distance information. When the distance from the driver's own car position to the next crossing is below the prescribed distance, the operation processing part 20 transmits a GPS signal and a positioning signal to a base station B, allows a server S to calculate the present position information, and acquires the calculated present position information through the base station B. COPYRIGHT: (C)2004,JPO |
