Patent ID: 6737985
Filing Date: 2004-05-18
Classification: G08C,H01Q

Abstract:
A remote metering system comprising:a plurality of remote meters each of which includes an antenna, a transmitter for transmitting meter signals via the antenna, a receiver connected to the antenna for receiving and filtering an incoming radio frequency signal, and a carrier signal detection circuit which is connected to receive the filtered radio frequency signal and which is operable to detect the presence or absence of a carrier signal, and to prevent activation of the transmitter in response to the presence of a carrier signal, or to activate the transmitter in response to the absence of said carrier signals; a plurality of concentrator units arranged for direct RF communication with respective groups of remote meters to receive respective meter data therefrom; and a central control unit arranged for communicating with the plurality of concentrator units for receiving meter data from the plurality of concentrator units, wherein the remote meters in a meter group are operable to initiate communication with the corresponding concentrator unit during respective predefined time periods; and wherein the receiver is provided with a local oscillator signal by the transmitter (116), the transmitter (116) output being isolated from the antenna (120) during such provision of the local oscillator signal.