Abstract: A method for accessing data from a secondary device to enhance position data of a navigation unit is described. A short-range data link is established between a navigation unit and a secondary device. Secondary time data is received from the secondary device over the short-range data link. Secondary position data is received from the secondary device over the short-range data link.

Abstract: Detection of an impending tire failure event is accomplished using a transducer placed near a set of tires on a vehicle. A processor detects a characteristic sound indicative of an impending tire failure event in conjunction with sound information received from the transducer. A warning indication is transmitted by a transceiver to the driver of the vehicle and/or to a remote location in connection with the detection of a characteristic sound indicative of an impending tire failure.

Abstract: A container, a transponder, a method and a system are provided that are useful in determining the geographical position of a cargo container. In the event cargo containers are stacked one on top of another, those containers which lack a clear view of a satellite or terrestrial communications tower can transmit container ID information ultrasonically to containers that do have a clear view of a satellite or terrestrial communications tower. The containers having the clear views can transmit container ID information to remote networks using RF communications. The geographical positions of containers can be calculated locally or they can be calculated remotely by sending GPS data or trilateration data to a remote source for position determination.