Patent ID: 7428460

Claim:
A method of delivering map data in a system including a server, storing difference data between current map data and newest map data and a terminal, storing and displaying the map data, connected to the server through a network, wherein the server sends the difference data in response to a request from the terminal, the method comprising the steps of: (a) at the terminal, sending to the server a first request message that specifies an area of a map to be subject to updating from the current map data to the newest map data and requests outline difference data for displaying outlines of features to be updated at the specified area; (b) at the server, receiving the first request message and searching for the difference data corresponding to the area for displaying, in detail, the features to be updated; (c) at the server, extracting the outline difference data from the searched difference data; (d) at the server, sending the extracted outline difference data to the terminal; and (e) at the terminal, receiving the outline difference data and displaying the received outline difference data overlappingly on map data already displayed on a predetermined display unit.