AMR 101: The history and evolution of metering technology
Industry participants and those who would like to become involved with the automatic meter reading industry often ask the Automatic Meter Reading Association (AMRA) to explain emerging metering technologies.
Complying with their requests requires a discussion about data and hardware and also about how that data travels between the end-user and the entity that collects the information. Specifically, advanced metering technologies encompass devices, gateways, intermediate communications networks, backbone networks, head-end devices and legacy integration.
On a legislative and business level, there is good and bad news to report about automatic meter reading.
First the good news. Industry restructuring and pressures to reduce costs, improve performance and potentially offer new ser-vices have spurred a renewed interest in AMR systems. The trend has prompted new players to enter the market and will thrust AMR technology into the next millennium.
The bad news is that regulatory bodies in many states have yet to decide who will own the meter and the data it collects. This uncertainty has created a high level of interest, but has temporarily stifled widespread implementation of AMR.
The following information outlines the background and purpose of the components of an advanced metering system, and offers a glimpse of emerging technological trends.
Market needs prompt meter automation
Meters in general have the most inertia to change. Many of the trusted mechanical and electromechanical meters which continue to form the majority of meters installed are still in the early stages of their 15- to 30-year life cycle. This embedded base is often a major barrier for utilities considering AMR.
Any type of automation process requires the physical flow measurement of gallons, kilowatt hours or cubic feet to be converted into information that is sent to a central location. Suppliers have developed several devices that enable traditional meters to become automated through the conversion of rotation movements into electronic information.
The retrofitting devices, which need energy to convert information, are powered by batteries, remote lines, a gateway device or even the metered product. At this stage of technological development, the electric AMR meter has an advantage because it can receive power either before the meter (which the distribution company pays for) or after the meter (which the customer pays for).
Though meters often use flow to load and initiate spring-loaded moving magnets through a static field to create a pulse-per-unit measure, there is little useful energy that could power an electronic storage unit to retain this information for subsequent reading. In the not too distant future, however, meter developers may create gas-powered, water-pressure or flow-powered devices.
Emerging market demands have created a growing need for more intelligent meters. Trend-setting companies are developing electronic devices that incorporate digital readouts and software-driven functions such as time-of-day accumulations.
Gateway links meter and network
Dramatic changes are also taking place with gateway devices. Basically, the gateway provides a bridge between the meter and the communications network. The advent of full-scale microprocessors with robust operating systems now permits gateways to support a variety of protocols, devices, interfaces and functions. But, like meters, gateways need some form of power to operate.
The many types of gateways available today range from simple units that link the meter and the communications system to complex devices that provide local-user display and input from peripherals, such as intelligent panels and thermostats.
The communications link between the distribution company and the end-user usually dictates the gateway's level of technology and function.
Companies wanting to improve customer service in the competitive market are encouraging the development of more intelligent and flexible gateway devices that are configured by software rather than hardware. Just as computers now perform various applications, these devices may include ports for a variety of household appliances, including telephones, televisions and personal computers.
Data analysis spurs advanced communications
Communications links fall into two main categories wired and wireless. Wired services include standard telephone lines, power lines, dedicated and switched data lines, and broadband services, such as coaxial and fibre-optic cable. Wireless services range from one-way drive-by systems that use low-power transmitters to send data over unlicensed radio frequencies to fixed two-way networks using advanced communications technologies such as cellular and satellite.
Some systems use an intermediate communications node between the gateway and the utility to combine and distribute information to a limited number of devices within a particular area. These concentrating units allow data to be processed locally and the results to be forwarded to the head-end. Neighbourhood nodes also permit re-use of address and frequencies.
Communication between the neighbourhood node and the head-end often uses a higher bandwidth link, such as fibre-optic networks or conditioned high-speed dedicated data links.
An emerging trend in communications-link technology is the use of public wireless networks such as cellular and personal communications systems, as well as broadband wired networks. In these cases, AMR is an added benefit of implementation, not the compelling reason for the deployment of the infrastructure.
Once usage data travels from the meter through the gateway and across the communications network, the computer system at the master station is responsible for accumulating and processing the information before sending it to billing and other departments. Early communications systems were proprietary computers dedicated to operating the network. Now these systems have migrated to platforms including Windows NT and Windows 95, as well as workstations such as UNIX.
A compelling need for meter data in several utility departments which analyse the data for load balancing, SCADA, load profiling, forecasting and marketing, to name only a few uses has driven technological advancement. Creating interfaces that link these systems with existing legacy systems remains a key challenge to integrating meter data into utility operations.
Competitive strategy should include AMR
Despite the uncertainty sparked by deregulation, rapidly changing technology and demands to reduce costs, AMR still represents a key strategic and tactical initiative. In a competitive market, high-quality service will play an increasingly influential role in a company's ability to retain customers and revenue. Advanced metering technologies provide ready access to detailed customer information, which in turn allows companies to improve responsiveness and, even more important, identify ways to modify business offerings to meet the needs of a restructured environment.