Patent ID: 7352972

Claim:
A system providing bidirectional communication with remote devices comprising a plurality of lamp fixtures in fixed positions, each lamp fixture having unique identification information; power lines connected to each fixture for supplying AC electrical energy for each lamp fixture; and a base station coupled to the power lines; each fixture comprising: one or more lamps; a power supply comprising a rectifier, a filter, and a dual voltage power supply, the power lines electrically connected to the power supply to provide AC electrical energy; a power line carrier transceiver connected to the power lines adapted to receive a variable message including lamp fixture identification information transmitted by the base station over the power lines; a radio transceiver; a microprocessor control circuit having memory circuitry and programmed with lamp fixture identification information, the microprocessor control circuit coupled to the power line carrier transceiver and the radio transceiver, the microprocessor control circuit receiving the variable message from the power line carrier transceiver, the microprocessor capable of decoding the variable message, and, in response to identifying the lamp identification information and the decoded variable message, encoding a second variable message, including at least one remote device address and the identification information of the fixture, and activating the radio transceiver to transmit a radio signal with the second variable message; and the radio transceiver adapted to receive modulated radio signals from a remote device positioned to receive the second variable message transmitted by one or more radio transceivers of the fixtures, the remote device capable of decoding the second variable message encoded in the radio signal and responding to its address and the second variable message in the decoded radio signal by transmitting a second radio signal to the radio transceiver, the second radio signal including the identification information of the fixture from which the remote device received the radio signal.