| 摘要 |
<P>PROBLEM TO BE SOLVED: To update map data within an allowable time without causing inconsistencies. <P>SOLUTION: A map data distribution server maintains a first map data corresponding to a plurality of regions and a second map data which is a version newer than the first one. A terminal device maintains the first map data, and the map data distribution server prepares a plurality of update elements to update the first map data to the second map data and calculates time required to update the first map data on the basis of each of the update elements, based on the amount of the data included in each of the update elements and the number of the regions to be updated by each of the update elements. The terminal device updates the first map data based on the update elements of which calculated total time required for updating is less than a specified update time, among the update elements transmitted from the map data distribution server. <P>COPYRIGHT: (C)2012,JPO&INPIT |
