| 摘要 |
<p>A map update data supply device includes: a request update data extraction unit that based on an update request extracts a request update section, and a latest version of an overwrite update data file for overwrite updating; and a safeguard update data extraction unit that extracts a safeguard update section that safeguards a network between adjacent sections, and up to an update safeguard version of a difference update data file, wherein the extracted data files are supplied to a navigation device.</p> |
