Patent ID: 8155869

Claim:
A navigation system comprising: an information center that is disposed outside of a vehicle; a navigation device that is arranged in the vehicle, and communicates with the information center by data communication; a communication unit that is arranged in the navigation device, and transmits information about a destination to the information center; a center side transmission unit that is arranged in the information center, searches positional information of the destination in a database of the information center, and transmits the positional information to the navigation device; a calculation unit that is arranged in the navigation device, sets the destination based on the positional information input from the information center, and calculates a first route to the destination; a navigation side transmission unit that is arranged in the navigation device, transmits first route calculation result to the information center; and a determination unit that is arranged in the information center, sets the destination based on the positional information, calculates a second route to the destination, compares second route calculation result with the first route calculation result input from the navigation device, and determines whether the navigation device can appropriately guide an optimum route to the destination based on the first or second route calculation result, the information center is configured to specify a section between two adjacent passing points, at which the navigation device cannot appropriately guide the optimum route, when the determination unit determines that the navigation device cannot appropriately guide the optimum route to the destination, the information center is configured to transmit data of a guide message and data of positional information to the navigation device in order to guide a new road in the second route at a specified section, the information center is configured to calculate the new road and the new road is not stored in a database of the navigation device, the data of the guide message being used for executing a simple guidance of a name of an intersection, a name of a road or a traveling direction, the data of the positional information showing a position, at which the guide message is output, the navigation device is configured to receive the data of the guide message and the data of the positional information, and the navigation device is configured to execute the simple guidance based on the data of the guide message and the data of the positional information.