©04 The Media Desk
With apologies to the Bard of Avon.
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It's not a brand new technology, but it is a newer application of existing technology.
It sounds like a really neat and maybe even a good idea.
Until you start looking into it.
For years now some power companies have been using communication signals over the power lines to 'talk' to things such as substations and transformers and even your home electric service meter. Messages are sent as fast as the electricity through the wire to let control centers know where there may be a problem and that something needs to be done to correct it.
Usually it works fine, until there is an incident such as the most recent great northeast blackouts. And since it works in the 500 Khz spectrum, nobody else notices or cares.
It is just a small step to increase those signals to feed broadband internet service to customers over those very same electric wires.
There are several test markets in the US. Including the Manassas, VA area and around Boise, Idaho.
According to IDACOMM, Idaho Power and related companies, they can offer up to three megabytes per second connection speeds. Although ranges in the 500 plus up to 1.5 MPS are more common. The average price seems to be about thirty to fifty dollars per month.
Earthlink, ConEd, and other partners in the technology, including a large group of electric companies (see links below) are all for it.
The technology itself is not new in the least.
It is done the same way DSL is put on a phone wire…
To wit: Radio waves are used to encode the digital signal (no- DSL is not a TRUE end to end digital service) and run it at a higher frequency than the regular voice signal. A signal trap then pulls the DSL off the phone line and allows voice communications to go on its way while the Internet Traffic is sent to a router to feed your computer.
The basic principle works just as well for cable internet. The TV signals are at one frequency, the Net is at another piggybacked on the same wire.
In the case of Broadband over Power Lines (BPL) [Power Line Communications PLC in Europe] the radio waves carry the Net signal through the power system to be picked up by a filter on the customer premises. Just as with the phone and cable connections. Other suppliers used the power lines to bring it to a box outside, then install a Wireless transmitter to connect it to the computers inside the house, making BPL a hybrid connection.
With repeaters, distance is not an issue as it is with DSL. And currently, multiple subscribers on the same feed doesn't seem to decrease available bandwidth per subscriber. Although as BPL is installed in more locations, those facts may change.
Except there is one major difference in the delivery.
Phone cables are made up of twisted pairs. Two small copper wires tightly twisted around each other to reduce interference (incoming and outgoing) and maintain signal strength. With coaxial cable, the outer shield protects the signal on the center wire.
Power lines in the US are neither twisted nor shielded. And in some cases, not even insulated.
So it will create a little interference and static. So what?
Well. The way it was done in Austria and Denmark, it didn't create 'a little' interference. And the way it is working in several test locations in the US and Canada, it isn't creating 'a little' interference.
In areas where BPL was in service HAM radio was all but knocked off the air. There were reports of VHF TV interference with broadcast channels 2 through 6. AM Radio was disrupted at times.
And more seriously. HF (High Frequency) radio used for emergency communications was disrupted.
The frequencies used to transmit broadband over the power lines is right in the middle of the HF spectrum up to the low VHF frequencies. The power lines are unshielded. Since the outbound feed for the AC current is not directed, such as with phone cables, the signal goes everywhere regardless of whether or not the customer on the other end has the equipment to receive it.
Every power line, street light, traffic signal, house, and business is receiving the internet signal.
Therefore: Every traffic light, toaster, air conditioner, and electric transmission line in town is radiating, actually BROADCASTING, the signal right in the middle of the HF or VHF ranges.
As noted in various Amateur Radio newsletters including http://www.w9og.org Austrian authorities pulled the plug (so to speak) on BPL after numerous complaints of totally disrupted communications. Including:
the case that brought the issue to a head was a Red Cross report that emergency services radio traffic during a disaster response drill last May was the victim of massive BPL interference.
In Japan the disruption in some areas was nearly total. Including a description of some transmitters as being 'jammed'.
Finland stopped deployment as well because, in part, that "PLC would totally stop home reception of analogue and digital broadcasting transmissions on the HF band in the normal home." www.darc.de
But according to FCC Chairman Michael Powell the regulatory agency is more interested in wiring all American Homes for the Net than maintaining the traditional backbone of emergency communications.
"With BPL you theoretically reach every American with broadband to every power plug in America. … Our goals of universal service will be substantially advanced if that service were fully deployed." found at- http://www.arrl.org/news
More comments by Chairman Powell at Infoworld.com
He did acknowledge some concerns of interference, but skipped over it and went on to discuss other means of ensuring connectivity.
In short. Powell is a political animal. The power companies have deeper pockets than fire departments or Ham operators. Money Talks, so the Hams won't.
Is it only the amateur radio crowd that is up in arms?
FEMA, the Federal Emergency Management Agency, is dead set against it.
FEMA has concluded that introduction of unwanted interference from the implementation of BPL technology into the high frequency radio spectrum will result in significant detriments to the operation of FEMA radio systems such as FNARS (FEMA National Radio System) FCC Report
The above paper was sent to the FCC from FEMA during the comment period on opening up the US market for BPL.
The FCC ignored it.
Now the other side of the coin.
If BPL is going to cause interference for the radios. Won't the radios cause interference with the BPL?
The short answer is "Probably Not… but…"
Power lines already have a dampening field around them. The transmission of the electric current generates an electromagnetic field. However, it is usually low level and in most cases, unnoticeable.
BUT… There are scattered problems with "dirty power", A/C current with characteristics that can mar the performance of some sensitive equipment. Which requires voltage scrubbers, rectifiers, and other equipment to clean up. Some medical equipment comes with on board units to clean up the power before it goes any further into the unit for that very reason. BPL could add to that problem through unwanted stray frequencies interacting with sensitive instrumentation. Requiring even further shielding, and cost, in those types of equipment.
To sum it up. While BPL could be a good idea, and maybe have some applications in some places. It is not the magic fix for universal WEB access as Mr. Powell sees it.
This issue is far from settled. And at least one US Congressman is lining up against BPL.
Representative Greg Walden (R- Oregon) has asked the FCC to reconsider various points on the matter and delay wider implementation of BPL until more is known about its unintended effects.
Where will the ball finally come to rest?
Most likely. There will be a hodgepodge of laws covering BPL, no conclusive ruling, and a smattering of locations across the country where it is available.
And, of course, the price will go up.
Part of the FCC file at FCC.gov (PDF file)
ARRL, the national association for Amateur Radio
Powerline Communications Association plca.net
Idaho Power's idacomm.com BPL info page
CR+T overview http ://www.crt.net.au/etopics/bpl.htm
Wave Report looks at BPL
What is…. BPL
Cincinnati area rollout by e4engineering.com
Miami Herald article www.miami.com
Earthlink and BPL
Yahoo Business biz.yahoo.com
And… the STOP BPL page from Australia http://homepages.ihug.com.au/~vk5vka/
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