Modular wireless fixed network for wide-area metering data collection and meter module apparatus

• US 20060097892A1
• Filed: 12/22/2005
• Published: 05/11/2006
• Est. Priority Date: 09/13/2001
• Status: Active Grant

• Current Assignee: Sensus Spectrum, LLC (Xylem, Inc.)
• Original Assignee: Mholding LLC
• Inventors: Zigdon, Shimon, Heth, Carmel
• Granted Patent: US 7,782,225 B2
• Time in Patent Office: Days
• US Class Current: 340/870.02
• CPC Class Codes: G01D 4/002 Remote reading of utility meters
• CPC Class Codes: H04B 1/662 using a time/frequency relationship, e.g. time compression or expansion
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04M 15/68 Payment of value-added services
• CPC Class Codes: H04M 2215/0196 Payment of value-added services, mainly when their charges are added on the telephone bill, e.g. payment of non-telecom services, e-commerce, on-line banking
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04Q 2209/10 using a centralized architecture
• CPC Class Codes: H04Q 2209/40 using a wireless architecture
• CPC Class Codes: H04Q 2209/60 for transmitting utility meters data, i.e. transmission of data from the reader of the utility meter
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
• 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 scalable and modular fixed-base wireless network system for wide-area metering data collection, composed of at least one of each of the following components: meter modules, which monitor, store, encode and periodically transmit metering data via radio signals (air messages). The network may contain both one-way (transmit only) and two-way (transmit and receive) meter modules; Receiver Base Stations, which receive, decode, store and forward metering data to a central database and metering data gateway, referred to here as the Data Operation Center (DOC). Base Stations do not perform any meter data processing, but simply transfer decoded air messages to the DOC; and a Data Operations Center, which communicates with all of the network'"'"'s Base Stations and receives decoded air messages from the Base Stations. The DOC processes, validates and stores metering data in a meter database that it maintains for the entire meter population operating in the network. The DOC has the capability to export or forward metering data to other systems via standard data protocols, which may be scaled up in its air message handling capacity and in its application features, by integrating it with a wireless data-forwarding (downlink) channel, such as a paging network, which is required in order to provide service to two-way meter modules that may be operating in the network. This channel enables the sending of time synchronization and other commands to two-way meter modules, thus providing the operator with considerable flexibility in their choice of network capacity, features and system cost.

Claims

1. A scalable and modular fixed-base wireless network system for wide-area metering data collection, composed of at least one of each of the components a,b,c described below, which may be scaled up in its air message handling capacity and in its application features, by integrating it with a wireless data-forwarding (downlink) channel (component d below), thus providing the operator with considerable flexibility in their choice of network capacity, features and system cost. The network components referred to above are:

a. Meter modules, which monitor, store, encode and periodically transmit metering data via radio signals (air messages). The network may contain both one-way (transmit only) and two-way (transmit and receive) meter modules.

b. Receiver Base Stations, which receive, decode, store and forward metering data to a central database and metering data gateway, referred to here as the Data Operations Center (DOC). Base Stations do not perform any meter data processing, but simply transfer decoded air messages to the DOC.

c. A Data Operations Center, which communicates with all of the network'"'"'s Base Stations and receives decoded air messages from the Base Stations. The DOC processes, validates and stores metering data in a meter database that it maintains for the entire meter population operating in the network. The DOC has the capability to export or forward metering data to other systems via standard data protocols.

d. An optional wireless downlink channel, such as a paging network, which is required in order to provide service to two-way meter modules that may be operating in the network. This channel enables the sending of time synchronization and other commands to two-way meter modules.

2. The network system of claim 1, which also enables optimal adjustment of network control parameters, namely the quantity of Base Stations, the number of reception frequency channels and meter module message bit rate, according to the application requirements, namely message delivery probability, metering data latency and meter module battery life.

3. The network system of claim 2, which further includes Network Transceiver/Repeater (NTR) devices, designed to enhance network coverage in areas of poor or no initial coverage. The NTR devices repeat messages only from designated meter modules, identified either by module identification number or by an appropriate flag in the meter module air message.

4. The network system of claim 2, which also includes a logarithmic table encoding method for compressing interval consumption data air messages, thus reducing the number of bits required in the message per each consumption interval.

5. The logarithmic table encoding compression method of claim 4, in which the DOC maintains a large list (bank) of consumption encoding/decoding tables, adapted to various consumption patterns. The DOC further maintains a registry specifying which set of encoding/decoding tables is assigned to each meter module, these sets of tables potentially different from one meter module to another.

6. The network system of claim 2, which also includes an interleaving encoding method for interval consumption data air messages, thus increasing the data'"'"'s redundancy level and/or providing data for smaller consumption intervals. Each interval consumption data message'"'"'s time base is shifted, compared to the previous message, in a cyclic manner, so that interval consumption data may be reconstructed even if some of the messages are not received.

7. A low-cost high-output-power meter module, which may operate on the network system of claim 2, that includes a sensing means, data storage and processing means, a direct sequence spread spectrum transmitter and an antenna, all within the same physical enclosure.

8. The meter module of claim 7, in which the module enclosure may be assembled inside the enclosure of an electric meter.

9. The meter module of claim 7, in which the module enclosure may be assembled between a gas meter and a gas meter index.

10. The meter module of claim 7, in which the output power of the radio signal is between 0.5 and 1 Watt.

11. The meter module of claim 7, which is equipped with a power supply, in which a capacitive element and a limited current source are combined, in order to allow high output power during a short transmission burst, which may also be initiated to immediately notify of power outage;

the capacitive element and the limited current source also imposing a physical limitation on the charge time and thus the transmission duty cycle, that way reducing interference that may be caused by a malfunctioning meter module, to an acceptable level that does not affect network functionality.

12. The meter module of claim 7, which also maintains low power consumption of its meter interface circuitry and low overall power consumption, by using two sensors to detect rotation, of which at one time only one (or none) may be at a closed switch status. By disabling a sensor circuit immediately once it is detected at a closed switch state, while simultaneously enabling the other sensor circuit, near zero current is drawn by the circuit.

13. The meter module of claim 7, which also includes an outage recovery system, consisting of the following measures:

Immediate notification of outage (‘

last gasp’

)

Immediate notification of power restoration

Storage of interval consumption data prior to an outage event, enabling a transmission of the last saved data shortly after power restoration

14. A low cost Binary Phase Shift Keying (BPSK) RF signal modulator, implemented on a four-layer PCB, providing high performance at a very low cost compared to microwave monolithic integrated circuit (MMIC) BPSK modulators.