From GLCP web site www.greenlandcorp.com
AirLinkT
Wireless, Fixed Network Automated Meter Reading Network
Utilities are going through a period of rapid change triggered by government's deregulation mandate. While the real race may be to develop unique products and services to capture (and hold) the customer, the bottom line is the urgency for utilities to capitalize on the interactive services that technology is making possible.
Utilities, like telecommunications service providers, face massive regulatory change that is reshaping the business landscape. The principal challenge is to manage the transformation from monopolies to competitive service-oriented businesses.
With competition comes a two-headed monster: Utility companies must learn to drive cost out of their operations while improving service quality and adding new features.
Meters, which measure the flow of commodity resources (electricity, natural gas, water) are a utility's lifeline. Information retrieval, however, is an expensive and inefficient process that is both labor-intensive and error-prone. Furthermore, the meter reading process is generally limited to daylight hours; and it results in only a single data point of the total resource consumed. This method provides practically no statistical energy management information.
Automated meter reading ("AMR") of electric, gas, and water meters has the most obvious benefit of reducing utility company costs. However, the most significant benefit to such automation is enhanced information retrieval and management. Additional benefits include utility load control management, theft and tamper detection, service interruption detection, and automation of some parts of the distribution system ("SCADA"). A "smart" network will enable utilities to manage costs and service quality efficiently and effectively.
Greenland has developed such a network - Airlink, a completely wireless, fixed network AMR system designed as a communications link between a utility and every individual user of resources in its service area!
Why automate?
The major issues facing the utility metering process are: (1) access to the meter (which may be in the basement of the home, or in a remote location); (2) having enough qualified personnel to handle the work load; (3) assurance of the accuracy of the information (hand writing the information in the field and then transferring it to billing computers breeds inaccuracy); (4) costs (including salaries, employee benefits, insurance, fleet maintenance, etc.); (5) cash flow (some utilities can send bills to its customers only once every 2 months; automation can decrease the length of the billing cycle because meters can be read more frequently); and (6) energy management (utilities need information at the point of use in order to get better information as to resource usage, including time, amount of use and, in some cases, power interruption status).
Why is AirLink a superior solution?
Most AMR solutions rely on either a hard-wired solution or a wireless solution that requires the collection device to be in relatively close proximity to the meter. Other wireless systems require meter reading personnel to be deployed in the field to accomplish data collection. Advanced wireless technology is a major differentiating characteristic of the AirLink system. The system enables a utility to read meters, regardless of location, without the need to use hard-wired connections or to send reading personnel near the location. The system is an entirely remote-controlled network, with collector stations strategically placed in the general area of the meters. A single collection station can accommodate thousands of meters, reading approximately 500 points per second. Meters can be polled many times daily. (AirLink defaults to reading meters in 15-minute increments.) Data is collected in real-time, without the need for field personnel. Additionally, the system automatically informs the main office of power interruption at the meter site ý power failure or tampering with the system is detected within seconds of such an event.
State of the Market
As one would expect, the United States represents the most sizable market for delivery of essential utility services such as water, electricity, and natural gas. Accordingly, the U.S. represents the largest single market for meter systems and services ý approximately 102 million homes comprising 300 million meters.
Market surveys show that automated meter-reading devices can be grouped into three basic types with increasing levels of sophistication: (1) hand-held, (2) hard-wired, and (3) radio telemetry.
Hand held devices are used by meter reading personnel that replace hand-written data through key entry. The individual meter reader keys the meter reading into a hand-held recorder that places the data onto a recording media, such as tape, for later loading into a computer program. This tool eliminates one or more steps in the transcription process, but does nothing to improve meter reading productivity. This technology is currently being employed by water, gas, and electric utility companies. Meter reading personnel must be able either to see the meter face and transfer the reading into a recorder, or to touch its face or a special plate with a wand or other reading device. The primary benefit of hand held devices is that they eliminate the hand-written recording of meter data and subsequent manual data entry into the utility's billing computer. Wand-type devices, however, require a special meter that contains electronic circuitry for the system to function. While this may be viable for new housing developments, it is not practical for existing communities due to the high cost associated with replacement of existing meters.
Hard-wired devices include automated meter-reading devices that are interfaced to existing telephone circuits (or other wired connections). This method represents a relatively high capital investment and the need for a telephone or other hard-wired connection. Devices currently in use have been implemented with telephone circuits to transmit data directly to a utility. One device uses a dial-in technique whereby the meter dials the telephone number of a computer system and transmits the reading. An alternative system employs a dial-out method whereby the utility's host computer dials the telephone number of the meter in order to acquire the meter data. In both systems, telephone line charges apply. Another system currently in uses implements a hard-wired system for metering electric usage. The system uses a distributed network of microcomputers to collect data from a group of instrumented meters. Existing power lines are used for data communications until the line reaches a transformer. There are physical limitations associated with the amount of data that can be passed through power lines. However, the system will allow remote reading and control functions for an electric utility. These systems are very capital intensive and require a significant level of technical support related to installation and maintenance. Nevertheless, hard-wired systems have advantages over hand-held devices since they are automated and can be accessed at any time to obtain meter readings in support of load management activities. It is potentially very costly for a utility to install these systems due to the complex communications, networking, and interface electronics required for meter sensing. In addition to the high capital costs, these systems are somewhat limited by the inherent physical constraints of the telephone system (or other hard-wired connection) band width. Timing becomes critical in an environment with a large population of meters. The time required to dial, establish communications, transmit data, and close communications is critical to the effectiveness of these devices. Although they provide a potentially long service life, they are inherently limited due to the time required to complete a reading cycle.
Radio telemetry devices, until recently, have been limited to collection of data by a mobile platform to collect the data from meter sensing devices via radio telemetry. The basic requirements of these systems to be successful are that (1) the system must provide more than a single data point; (2) the system must be non-intrusive and capable of retrofitting to the installed base of meters; (3) the operator interface must be designed so that it can be easily used by existing meter reading personnel; (4) the system must be reliable, inexpensive, and capable of operating in harsh environments; and (5) the meter reading unit must be capable of being mounted to the meter in such a way as to allow for the manual reading of the meter in case of system failure. Unfortunately, such systems have not met such requirements in total. A major disadvantage is that meter reading personnel must still be used for the data collection process. Notwithstanding the reduction in personnel requirements, staff must be retrained and re-deployed to serve the system from vehicles designed to interact with the communication of data from each meter to the collection point(s). A second major disadvantage is that these systems have not been designed to adequately function in all conditions (i.e. in sunlight, or harsh weather conditions). Additional technical challenges have yet to be solved to a reasonable degree to insure total system reliability. These include transmission inconsistencies, route coordination, etc.
It is important to note that traditional meter reading methodology does not provide utilities the ability to implement incremental billing to enable differential charges for usage based upon usage patterns that impact resource management.
In an increasingly automated age, utility companies must adapt to technologies that have the potential to increase their productivity and level of customer service. Automating meter reading is one of the principle methods by which utilities can positively transform their operations.
AirLink Technology
The key to the AirLink network is Greenland's patent-pending radio frequency (RF) technology; and associated technology devoted to the unique requirements of utility meter reading and information management.
The AirLink wireless meter reading network is made up of essentially two parts: (1) the meter reading device that is installed on the utility meter itself, and collection devices, which are located at intervals throughout the service area. The system electronically takes an electronic "picture" of the meter's output, creates a digital "packet" of the actual meter reading, and transmits the data to the collection station. The data is then available to the utility company to incorporate into its existing computer systems for billing and statistical analysis. (A database software interface is provided for virtually any system.) The meter reading device ("MRU") is easy to install and to maintain. Most installations are estimated at 10 minutes in duration. Greenland recommends a project management change-out approach, which calls for a meter shop "bench" retrofit installation. MRU devices can also be installed in the field.
Meter Reading Device
AirLink MRU's are available for any kind of utility meter. Circuitry is provided to capture data from the meter and to translate it for digital transmission. The major components include a transmitter with a specialized, horizontally polarized antenna, receiver, power supply with supercapacitor (battery), an internal computer to translate data, and memory for storage of data (typically 150 'reads').
Electric water, and gas meters are read via sensors, which detect the rotation of moving parts inside the meter or the register of the meter (depending upon the type of meter to be automated). The most common AirLink application for electric meters includes a sensor circuit that includes a photo-transistor, which consists of an optical detector and a light emitting diode (LED). The emitter is mounted above the meter disk, and the detector below. The output voltage decreases in the absence of light, and increases in the presence of light caused by the alignment hole in the meter disk passing in front of the sensor. Output is fed into an automatic level control (ALC). This circuit offers automatic adjustment of its trigger level to accommodate various light sources, changes in ambient light, or optical sensor misalignment. When a hole passes in front of the sensor, an abrupt change in voltage occurs, which triggers a "read". If the ambient light slowly changes (sun coming up, going down, cloud passing over, etc., the detector's input will change with it, without triggering the output. A system of measurement established by the International System of Units is the basis by which the AirLink device is calibrated.
The AirLink MRU is designed to last for many years without the need for repair or replacement. The AirLink electric meter MRU is powered by line voltage and a supercapacitor. Water and natural gas MRU's use long-life lithium batteries that may be either replaced or re-charged every three to ten years (depending upon how frequently meter must transmit data).
The meter reading device has its own computer circuitry, including memory, in order to save data for up to 150 reads to provide redundancy of data, and to insure against data loss due to vandalism, power outage, etc. Communications.
The AirLink system addresses two main technological issues related to automating the process of meter reading: (1) meter reading accuracy and (2) communications integrity. Greenland's patent-pending communications protocol and associated technology will enable utilities to receive data from millions of meters in short periods of time. The system effectively deals with the challenges related to data compression and signal integrity; particularly when applied to the needs of utilities to transmit from thousands of data points in short periods of time. At present, the following communications parameters are provided with the AirLink transmitter located at each meter:
Frequency: UHF (tuned to x mHz)
Antenna: 4.7 in. [inside meter]
Power: Line voltage + battery
Install time: < 10 minutes
Data rate: >100,000 bps
Transmit time: 24 hours per day
FCC: Part 90 compliant
The Company's patent applications relate to the modulation and filtering of digital signals, more particularly binary data signals.
( HOME | AirLinkT | Company | News | Financial | Employment | Email
c 1997 Greenland Corporation
7084 Miramar Road, Fourth Floor
San Diego, CA 92121
TEL: 800/234-4226, 619/566-9604 FAX: 619/566-9796
EMAIL: info@greenlandcorp.com
|
