Patent ID: 7672778

Claim:
A method of operation for a navigation system that includes a mobile unit and a server located remotely from the mobile unit, wherein the mobile unit obtains geographic data by requesting the geographic data from the remotely located server, the method comprising the steps of: prior to transmitting data that indicates a destination to the server, downloading an initial set of geographic data from the server to the mobile unit, wherein the initial set of geographic data represents an area located around a current position of the mobile unit while a user is operating the mobile unit to specify the destination; transmitting the data that indicates the destination to the server; if the destination is not located within the area represented by the initial set of geographic data, receiving data from the server in the mobile unit that indicates an intermediate location located within the area represented by the initial set of geographic data, wherein the intermediate location is located along a route to the destination calculated by the server; on the mobile unit, calculating a route to travel to the intermediate location; and downloading additional geographic data from the server, wherein the additional geographic data represents an area from the intermediate location to the destination.