| 摘要 |
PROBLEM TO BE SOLVED: To provide a simplified method and system for car navigation capable of decreasing unrelated data transmission quantity, and increasing correctness rate of wireless transmission. SOLUTION: A service center at a far place computes for a driver all the routes to pass to go from a start place to a destination, selects specific geographic area covering the routes, where the specific geographic area is discriminated from other geographic area by two diagonal angular points, and parted into a plurality of geographic zones by set two-dimensional grid numbers to be respectively defined with two-dimensional codes. The service center sends the two angular points, and the set two-dimensional grid numbers, mentioned above, as well as the two-dimensional codes for all the geographic zones corresponding to the routes to an on-board unit. The on-board unit reduces them to a two-dimensional grid drawing corresponding to the specific geographic area, responds to all the small grids, and displays current small grids where a vehicle exists, so that the driver is capable of easily searching a forwarding direction. COPYRIGHT: (C)2005,JPO&NCIPI |
