Electronic navigation system and method

A routing system which makes a large amount of information available to a remote unit, the system comprising:

• (a) a base unit;
• (b) a remote unit including a navigation application program installed therein;
• and
• (c) a communications link to electromagnetically transmit a route request from the remote unit to the base unit and to electromagnetically transmit data representing a route from the base unit to the remote unit in response to the route request;
• wherein the remote unit
• (i) receives the data representing a route transmitted by the communications link,
• (ii) compares the data representing a route received with coverage of databases on-board the remote unit,
• (iii) uses said navigation application program to determine what additional data is needed, and
• (iv) electromagnetically transmits from the remote unit to the base unit, via the communications link, an additional request for the base unit to provide said additional information.

A system for providing navigation features to remote mobile navigation units comprising:

• a plurality of remote navigation units each of which is installed in a respective one of a plurality of vehicles, wherein each of said plurality of remote navigation units is comprised of:
• a position indicator that provides an output indicative of a geographical position thereof;
• an input device that provides for receiving a request for a navigation function from a user;
• a first processor coupled to receive outputs from said position indicator and said input device, and further wherein said first processor executes a first navigation application program to provide the requested navigation function to the user of the remote navigation unit;
• a first geographic database installed in said remote unit and used in conjunction with the first navigation application program executed on the first processor of the remote navigation unit;
• wherein said first navigation application program determines what additional data beyond what is included in said first geographic database is required to provide said requested navigation function to the user;
• and
• a first wireless communications system coupled to said first processor to provide for sending requests for said additional data and receiving responses to said requests;
• and
• a base unit comprised of:
• a second wireless communications system that provides for receiving said requests for said additional data from each of said plurality of remote navigation units and sending responses thereto;
• a second geographic database;
• and
• a second processor coupled to said second wireless communications system and said second geographic database, wherein said second processor executes a second navigation application program that prepares responses to said requests from the plurality of remote navigation units using said second geographic database and sends said responses to said plurality of remote navigation units using said second wireless communication system;
• and
• wherein said first navigation application program provides said requested navigation function to the user using data from said first geographic database and said additional data from said second geographic database.

A method of providing navigation information to a plurality of users of remote navigation units comprising the steps of:

• on each of said plurality of remote navigation units,
• receiving a request for navigation information from a user;
• executing a first navigation application program that uses a first geographic database installed in said remote navigation unit to provide a first part of a response to said request for navigation information and determine whether additional data are to be requested from a base unit;
• using a wireless communication system to communicate a request to said base unit navigation system to obtain said additional data related to said request for navigation information as determined by said navigation application program;
• receiving said additional data related to said request from said base unit navigation system;
• combining said first part of a response with said additional information to provide a combined response;
• and
• providing said combined response to said user.

A method for providing improved navigation services to a plurality of remote navigation units comprising the steps of:

• on a remote unit comprising a first navigation system that includes a first geographic database and a navigation application program, receiving input from a user for a desired navigation function to which a response requires geographic data;
• from the remote unit, using said navigation application program to transmit a request for part of said geographic data not in said database determined by said program as required to provide said desired navigation function;
• on a base unit comprising a second navigation system that uses a second geographic database, receiving said request and providing said part of said geographic data using said second geographic database;
• from said base unit, transmitting said part of said geographic data to said remote unit;
• and
• in said remote unit, receiving said part of said geographic data from said base unit and using said part of said geographic data received from said base unit along with data from said first geographic database to provide said desired navigation function to said user.