System for automatic meter reading

• US 6,477,386 B1
• Filed: 04/20/2000
• Issued: 11/05/2002
• Est. Priority Date: 04/20/1999
• Status: Expired due to Fees

• Current Assignee: Advanced Technology Ramar Limited
• Original Assignee: Advanced Technology Ramar Limited
• Inventors: Giles, Terence George
• Primary Examiner(s): LE, THANH C
• Application Number:
  US09/552,875
• Time in Patent Office: 929 Days
• Field of Search: 455/39, 455/41, 455/46, 455/67.1, 455/68, 455/88, 455/108, 455/109, 455/517, 455/507, 340/870.01, 340/870.02, 340/870.03, 340/870.11, 340/870.15
• US Class Current: 455/517
• CPC Class Codes: G01D 4/006 Remote reading of utility meters to a non-fixed location, i.e. mobile location
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

A fixed network AMR system that has a range from the meter (4) to the node (6) of up to 5 km uses a common reference source (2) for the frequency reference of the meter transmitter (12) and the system receiver (18). By using a publicly available reference frequency the necessary frequency stability can be obtained in order to provide a signal to noise bandwidth of the order of 32 Hz.

Claims

1. A fixed network AMR system comprising a plurality of meters and nodes, each meter having a transmitter for transmitting data to at least one node, each node having a data receiver for receiving transmissions from meters within range of the node, wherein each meter and each node has a local oscillator and a reference receiver for receiving a common frequency reference signal as transmitted by a public source, said common signal providing a reference frequency for the local oscillators used by the meter data transmitters and the node data receivers.

2. A fixed network AMR system as claimed in claim 1, in which the common reference signal transmitted by the public source incorporates time data, wherein each meter and node has a clock and the reference receivers at the meters and nodes are adapted to receive said time data in order to synchronize the clocks in the meter and node.

3. A fixed network AMR system, as claimed in claim 1, wherein the meter transmitters generate a double sideband amplitude modulated signal with a suppressed carrier signal.

4. A fixed network AMR system as claimed in claim 1, wherein the node data receiver comprises an independent sideband receiver.