Near field signal properties are used to determine a location by utilizing two magnetic antennas arranged so that the null axes are perpendicular and lie in a plane of interest, such as the horizontal plane. The two antennas may be used as transmitting antennas or receiving antennas. The antennas may be driven so as to produce an equivalent of an omnidirectional pattern in the plane of interest by driving the antennas in an orthogonal manner. The orthogonal drive may be time orthogonal or phase orthogonal. A location is determined based on near field response which may include propagation properties, which may include amplitude, phase, relative amplitude, or phase, or other properties. In one embodiment, multiple transmitters are utilized to determine the location of a single receiver. In another embodiment, multiple receivers are utilized to determine the location of a single transmitter. A space efficient magnetic antenna is disclosed.

 
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> Time division multiple access system and method for using available TDMA slot time to transmit additional messages

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