Patent ID: 6822555
Filing Date: 2004-11-23
Classification: G08B,H04B

Abstract:
A life safety system using an electric power line communications system operatively associated with premises power distribution lines of an electric power distribution system to provide through the premises power distribution lines highly reliable communication links among modulated carrier signal receiving devices electrically coupled or located in proximity to the premises power distribution lines to convey hazardous condition alarm signals, comprising:multiple hazardous condition detectors adapted for placement and receiving electric power at different locations where premises power distribution lines are routed to make electric power available, each of the detectors having an identification address and producing a hazardous condition signal in response to detection of a hazardous condition in the location of the detector, the identification addresses in association with the power distribution lines contributing to establishment of communication links among the detectors; a power line transceiver operatively associated with each detector and designed to transmit and receive over the premises power distribution lines modulated carrier signals conveying information over the communication links, the power line transceiver operating in a transmitter mode as an intentional radiator to emit the modulated carrier signals by transmitting them at a frequency band and a power level sufficient to form by electrical conduction a communication link with a modulated carrier signal receiving device that is electrically coupled to the premises power distribution lines, and to form by at least one of electrical induction a communication link by coupling across electric power distribution line phases or electromagnetic radiation a communication link with a modulated carrier signal receiving device that is located in proximity to the premises power distribution lines; and the transceiver of each detector that produces the hazardous condition signal emitting a modulated carrier alarm signal over the premises power distribution lines for delivery to other ones of the detectors by the communication links to enable production of alarm signals at the premises locations of the detectors.