Accounting system and method in data communication network

An accounting system in a data communication network for a vehicle navigation system, comprising:

• a central computer, having a road/map database, for data communication with a user computer of a user;
• route guidance data generating means for generating data for route guidance from a current position of the user to a destination by retrieval of road/map data from the road/map database;
• transmitting means for transmitting the route guidance data from the central computer to the user computer;
• account calculating means for calculating accounts payable by the user in accordance with content and/or volume of the route guidance data transmitted from the central computer to the user computer;
• receiving means, at the central computer, for receiving traffic information from the user computer, wherein the received traffic information is referenced in generating the route guidance data by the route guidance data generating means;
• reward calculating means for calculating a reward for the user depending upon content and/or volume of the traffic information transmitted from the user computer;
• and
• billing means for billing the user an amount obtained by subtracting the reward from the accounts payable.

An accounting method for use in a data communication network wherein an information provider communicates with a user computer, comprising the steps of:

• receiving upload data transmitted from the user computer to the information provider;
• generating download data by making reference to the received upload data;
• transmitting the download data from the information provider to the user computer;
• calculating accounts payable by the user in accordance with content and/or volume of the download data;
• calculating a reward for the user in accordance with the content and/or volume of the upload data;
• and
• billing the user an amount obtained by subtracting the reward from the accounts payable.

An accounting method in a data communication network for a vehicle navigation system, wherein an information provider, having a road/map database, communicates with a user computer, comprising:

• generating route guidance data for guidance from a current position of the user to a destination, with retrieval of road/map data from the road/map database;
• transmitting the route guidance data from the information provider to the user computer;
• calculating accounts payable by the user in accordance with content and/or volume of the route guidance data transmitted from the information provider to the user computer;
• receiving traffic information from the user computer wherein the received traffic information is referenced in generating the route guidance data;
• calculating a reward for the user in accordance with content and/or volume of the traffic information transmitted from the user computer;
• and
• billing the user an amount obtained by subtracting the reward from the accounts payable.