A communication device comprising an internal power source, receiver means for receiving signals transmitted from the base station, and processing means selectively responsive to an interrogation signal received from a base station to generate a data signa...

A method of navigation guidance includes providing a communications node (104, 106), and a remote communications node (108). The remote communications node (108) requests a navigation route (201, 301) from communications node (102, 104, 106). The navigatio...

A vehicular navigational system (2) is provided that compensates for temperature-dependent drift of bias in a vehicle heading sensor (6) associated with a dead reckoning vehicle positioning system (12). Specifically, a Kalman filter (38) generates a calibr...

A voltage regulator that includes a voltage control circuit, fabricated on a semiconductor. The voltage control circuit maintains a voltage between a first node and a second node within a predetermined range by maintaining a current level flowing from the ...

A portable communication device (1,2,3) has a base member with a radio receiver (5), a measurement member with a pressure sensor (11) for detecting variations in atmosphere pressure, and means (6,9) for converting the signal produced by the pressure sensor...