This paper describes the authors' developed off-board car navigation system. This system consists of a server, on the Internet, and client terminals in vehicles of individual users. A client terminal requests the server calculate routes, send maps which the client does not have, and retrieve POI (Points Of Interest) through the Internet using a cellular phone. To reduce the number of connections to the server, the client terminal stores received maps in a compact flash card memory. Our off-board navigation system has (1) a center to provide navigation functions using the latest maps and POI through the Internet; and (2) a more compactly sized client terminal compared to conventional on-board systems. The authors evaluated the system by group interviews and field trials. The concept of the system was evaluated as acceptable, but some problems were identified which need solutions.
Abstract