BPL - Broadband Over Power Lines
By Enrique De Argaez, webmaster
Broadband via electrical wires is certainly an encouraging idea since nearly every home in the world is served by power lines. What’s more, most residences are threaded with electrical wires terminating in multiple outlets in almost every room. So homeowners can get a high-speed Net connection – up to 3 megabits per second – just by plugging a special modem into any outlet. That matches cable modem speeds and outpaces most DSL offerings.
What is BPL?
Broadband over Power Lines (BPL) also goes by a few other names and acronyms: Power Line Communications (PLC, Power Line Telecommunications (PLT), and Power Line Broadband (PLB) are terms also used. Most of these papers and links use the term “BPL.” There are a number of types of PLC systems, using different approaches and architecture. All are “carrier-current” systems, a term used to describe systems that intentionally conduct signals over electrical wiring or power lines.
The principle behind BPL is simple: Because electricity courses over just the low-frequency portions of power lines, there’s room for data to stream over higher frequencies. For years, utilities have sent basic network-maintenance data across their lines at relatively low data rates. Now, by installing more sophisticated computer chips into the network, they can send and receive fast data streams for more high-bandwidth applications, such as real-time, always-on meter reading. (Say good-bye to the friendly meter reader.) And for the first time they can offer new customer services, such as voice-over-Internet or even video on demand.
That, however, will require significant upgrades of utility substations and power lines. And nobody knows exactly how big an investment will be necessary. First, power companies have to mount boxes on certain utility poles to deliver data signals. Early estimates of installation costs range from $50 to $150 per home passed, plus $30 to $200 more for modems in each home, according to a study by EPRI and its consulting arm, Primen. Internet service provider EarthLink Inc. (ELNK ), which is testing BPL schemes with Con Edison, says that to make money from selling broadband access at $20 to $30 a month, a utility may have to get installation costs down to $20 per home passed and less than $100 per modem.
Given the challenges, utilities will welcome any cost savings from improved energy management. By injecting intelligence into the farthest reaches of the power system, utilities can monitor their networks in ways never before possible. Currently, for example, power companies don’t know about local outages until customers report them. With BPL systems watching the flow of data to individual homes, they can pinpoint the neighborhoods without light. While testing residential broadband service in Briarcliff Manor, N.Y. this summer, Con Edison discovered that BPL could help detect impending faults. A residential customer noticed that his Web service was slowing down. Con Edison crews traced the problem to a cracked insulator on a pole next to his house. Now the company is modeling normal circuit conditions, then looking at even slight deviations to spot budding problems on its systems. That’s a far cry from periodic street maintenance checks, which Con Edison and others mainly rely on today.
In an era of increasing power usage by computers and other digital devices, many utilities are hoping BPL will bring them closer to an elusive goal: demand management. To encourage conservation, power companies would like to charge customers more during peak demand and less at other times. To bill accordingly, they need to measure how much power a home consumes every minute of the day. BPL could help by taking constant measurements. Some experts argue that existing approaches, using two-way pagers, are good enough and that new wireless options are cheaper. But BPL proponents say their wires are faster and more reliable.
Today the very idea of a smart electrical network is in its infancy. But demand for cheap Web access is mounting and so is the need for better power management. To satisfy both ends, utilities could embrace broadband and bring the electrical system into the Internet Age.
Web Access from Wall Outlets
One day soon, getting a broadband connection at home could be as easy as plugging a cord into an electrical outlet in the wall. The same power lines that deliver electricity to light rooms and run refrigerators will transport messages, music, and video across cyberspace. To link up computers, music players, and TV set top boxes in a home network, people will no longer have to mess with a tangle of wires or Wi-Fi settings. Over the powerlines, they’ll have the convenience of plug-and-play.
Many power companies on the US and the world over are exploring so-called broadband over powerline (BPL). BPL deployment would bring more competition to telephone and cable companies that sell web access, more Internet penetration to rural areas and hopefully lower broadband rates for the Broadband Internet users worldwide.
There is Concern: RF Interference
Because power lines are not designed to prevent radiation of RF energy, BPL represents a significant potential interference source for all radio services using this frequency range, including the Amateur Radio Service. Overhead electrical power lines and residential wiring act as antennas that unintentionally radiate the broadband signals as radio signals throughout entire neighborhoods and along roadsides. Interference has been observed nearly one mile from the nearest BPL source.
Others lean on worldwide trial failures as strong evidence that the technology is doomed-for-obsolescence; during its run bringing plenty of trouble (and interference) to areas contemplating the option.
About the Author:
Enrique De Argaez is the webmaster of the “Internet World Stats” website. Since 2000 he has been collecting Internet Usage Statistics, and publishing the data for over 233 countries and regions of the world for free use by the academia, the global business community and the general public. For more information on Internet World Usage, please visit: http://www.InternetWorldStats.com