To prevent the occurrence of discrepancy in link attributes while suppressing increase in the amount of data to be communicated in updating map data.
A map data distribution server connected to a network is provided. The map data distribution server creates difference data items between first road data and second road data newer than the first road data, creates a plurality of update elements each of which includes one or more difference data items with respect to a single link or a continuous link. When a first update element includes difference data items with respect to the attribute of a first link sequence and a second update element includes difference data items with respect to links that belong to the first link sequence, the map data distribution server creates a third update element including the first and second update elements and, when an area on a map including the link with respect to the difference data items in the third update element is specified in accordance with a map update request, transmits the third update element.
MIHARA KEISUKE
| JP2004157172A | 2004-06-03 | |||
| JP2004117983A | 2004-04-15 | |||
| JP2004177245A | 2004-06-24 | |||
| JP2006220756A | 2006-08-24 | |||
| JP2005070482A | 2005-03-17 |
Masahiro Fujii
Masaaki Iida