Abstract: A system and method controls entry or exit of a vehicle to or from a vehicle lot. A tag transmitter is adapted to be mounted on a vehicle for transmitting a wireless RF signal that includes vehicle data relating to the vehicle. A lane sensor is associated with a vehicle lane through which vehicles pass for at least one of entering and exiting the vehicle lot and is configured to receive wireless RF signals from the tag transmitter when the vehicle is in the vehicle lane, while substantially rejecting wireless RF signals from other tag transmitters mounted on other vehicles within the vehicle lot or in an adjacent vehicle lane. A processor is operatively connected to the lane sensor and receives and processes the vehicle data to validate and control the vehicle's entry or exit to or from the vehicle lot.

Abstract: A communications system, such as part of a real-time location system, includes a transmitter that can be part of a location processor, tag emission reader or tag interrogator that generates a frequency shift key (FSK) modulated wireless communication signal representative of digital data and transmits the communications signal over a wireless communications channel. A receiver such as incorporated within a tag transceiver used in the real-time location system receives the FSK modulated communication signal. The receiver includes a circuit for calculating the magnitude of low and high tones of the FSK modulated communication signal and a threshold for amplitude shift keyed (ASK) channel data and FSK channel data to derive the digital data even in the presence of on-tone jammers in the communications channel.

Abstract: A system and method locates a wireless local area network (WLAN) signal source. A wireless LAN signal as an RF signal is propagated from a WLAN signal source at a fixed, known location to a plurality of receivers having unsynchronized clocks. The time-of-arrival is measured at each receiver and the timing relationship from the fixed, known location of the signal source is used to relate time-of-arrival measurements from a signal arriving from an unknown location.

Abstract: A system for locating an object within a monitored environment includes receivers arranged in loosely coupled networks. A tag transmitter acts as a network node and bridge between the loosely coupled networks. A processor is operative with each receiver within each network for defining a clock timing for each network, a system time for all networks, and tracking its relationship to the clock timing for each network for time synchronizing all receivers. The processor is also operative for conducting differentiation of time of arrival signals received from a tag transmitter to locate an object associated with the tag transmitter.