Patent ID: 8156076

Claim:
A mobile host for receiving map data distributed from a host computer, the mobile host comprising: a database for storing map data distributed from said host computer; and a schedule manager for managing a schedule of said mobile host; wherein said mobile host, upon receiving an update request for the map data stored in said database, detects a timing at which usage frequency of said mobile host becomes low as an indication that a vehicle in which the mobile host is installed has entered a freeway driving state, and calculates a required time period for the vehicle to remain in the freeway driving state as a map data updatable time at which said usage frequency is kept low from said detected timing through said schedule manager; wherein said mobile host then sends an update request to said host computer according to said received update request; wherein said mobile host further calculates a necessary processing time for updating update object map data included within update information received from said host computer as a response to said update request and a usefulness value of said update object map data based on a distance between a route or a destination point from an update point; wherein said mobile host further decides a processing order for said update object map data according to said processing time and said usefulness value calculated respectively for said update object map data; and wherein said mobile host updates the map data stored in said database according to said decided processing order.