US Patent 7801904 Navigation system with distributed computing architecture

A system and method for providing geographic data to end users' computing platforms. A server maintains downloadable geographic data that are organized into pre-computed parcels that correspond to pre-determined sub-areas into which the entire geographic region serviced by the server is divided. The server responds to requests from the end users' computing platforms for navigation services and data by sending selected pre-computed parcels of geographic data to the end users' computing platforms. The end users' computing platforms store the pre-computed parcels received from the server in a cache memory. The end users' computing platforms use the data in the pre-computed parcels to provide navigation-related features locally.