Abstract: Method and system for a distributed navigation system. The system comprises a client integrated with a mobile communication device (e.g. PDA, cellular telephone, etc.) and a server communicating via wireless carriers and the Internet. In one embodiment, the server obtains a user's initial position, a user-designated destination, and calculates a nominal route from the user's initial position to the destination. If a deviation from the nominal route is detected, the reroute tasks are divided between the server and the client according to a corridor area surrounding the nominal route. Mapping information related to the corridor area is stored in the client, and the amount of the stored mapping information depends on the storage and/or processing capabilities of the client.

Abstract: A system and method for providing navigational information to a user connected in real-time, such as through a wireless telephone, PDA, or other device. The system provides navigational information to the user in the form most useful to the user, such as according to landmarks, or the number of blocks until the next action. The system also provides directions to points of interest along the user's route. Further, the system allows the user to suspend and resume a session. Also, the system varies the sampling rate at which the user's location is examined, to enhance efficiency and convenience.

Abstract: Method and system for prediction-based navigation in a real-time distributed navigation system. In one embodiment, a server receives a request from a client comprising one or more position coordinates. The server estimates the user's speed, estimates total elapsed time, calculates an optimal route to the destination and sends a set of routing directions to the client. Moreover, the server estimates a route origin within an estimated comfort zone in order to calculate the optimal route from the estimated origin to the destination.

Abstract: In an Interactive Real-Time Distributed Navigation system a method and system is disclosed for implementing a warm start/cold start option. Through selection of the warm start option, an interactive session for providing navigational directions to a user is more quickly established because a user's position is assumed not to be ambiguous. A method of the invention verifies this assumption. Through selection of the cold start option, the method of the invention seeks to remove ambiguity in a user's position before providing navigational directions. If, however, a user's position is not ambiguous, the method of the invention reverts to a warm start condition to immediately transmit navigational directions to the user.

Abstract: An enhanced operating environment for an Interactive Real-Time Distributed Navigation system is disclosed. In the present invention, an enhanced operating environment is provided by improving input and output techniques in a navigation system. Disclosed are methods for reducing the number of inputs to a navigational sytstem through a wireless device. Improved input methods include methods for entering non-deterministic information to retrieve deterministic information. Also disclosed are improved output techniques including methods for pacing navigational prompts provided by a navigation system. The invention is applicable to text, graphics or audible navigation systems.

Abstract: A system and method for providing navigational information to a user connected in real-time, such as through a wireless telephone, PDA, or other device. The system provides navigational information to the user in the form most useful to the user, such as according to landmarks, or the number of blocks until the next action. The system also provides directions to points of interest along the user's route. Further, the system allows the user to suspend and resume a session. Also, the system varies the sampling rate at which the user's location is examined, to enhance efficiency and convenience.

Abstract: A method and system for interactive real-time distributed navigation employs improved techniques for input and output. The method and system may receive inputs through a wireless device. The operating environment simplifies and reduces these inputs. In some embodiments, the system receives non-deterministic input to generate deterministic information using a number of methods. The system may also employ improved output techniques including methods for pacing navigational prompts provided by a navigation system, and methods of providing navigational information to a number of users. The method and system are applicable to text, graphics or audible navigation systems.

Abstract: In an Interactive Real-Time Distributed Navigation system a method and system is disclosed for implementing a warm start/cold start option. Through selection of the warm start option, an interactive session for providing navigational directions to a user is more quickly established because a user's position is assumed not to be ambiguous. A method of the invention verifies this assumption. Through selection of the cold start option, the method of the invention seeks to remove ambiguity in a user's position before providing navigational directions. If, however, a user's position is not ambiguous, the method of the invention reverts to a warm start condition to immediately transmit navigational directions to the user.

Abstract: A GPS reference system and corresponding method utilizing a network of reference stations and a master station. Each reference station receives GPS signals from GPS satellites it observes and computes in response a pseudo-range residual for each GPS satellite it observes. The master station is in communication with the reference stations to receive the computed pseudo-range residuals and comprises a pseudo-range residual synchronizer, an ephemeris and clock correction estimator for each GPS satellite observed by the reference stations, and a transmitter. The pseudo-range residual synchronizer is responsive to the received pseudo-range residuals in order to compute clock differences between the reference stations and remove the clock differences from the received pseudo-range residuals so as to synchronize them.