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: 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.