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The Internet Science

Could Broadband Over Power Lines be Dangerous? 240

falconfighter writes " Broadband over Powerlines, once touted as the solution to many internet problems (developing 3rd world countries, etc.) has a new hazard. The system basically involves putting high amounts of modulated RF on a power line. The Amateur Radio Relay League has the most informative page on the topic. The hazards include exceeding MPE (maximum permissable exposure), RF burns, and disrupting the HF bands of radio. This last one would also work in reverse, meaning hams, airplanes, or the military keying up their radios could take out large areas of internet service (with airplanes, potentially over several hundred miles)."
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Could Broadband Over Power Lines be Dangerous?

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  • First, and... (Score:3, Interesting)

    by Zondar ( 32904 ) on Monday January 19, 2004 @11:07AM (#8020798)
    Being near a hot unshielded antenna lead of sufficient power output is bad news...
    • Re:First, and... (Score:5, Interesting)

      by grub ( 11606 ) <> on Monday January 19, 2004 @11:15AM (#8020875) Homepage Journal

      Being unshielded makes me wonder about the likelyhood of "sniffing" with a receiving antenna and amplifier. It's spread spectrum like the cable 'modems' but ya never know. I'm sure the NSA is ready for any potential rollout. :)
      • making it spread spectrum doesn't really protect you form eavesdroppers. you can still sniff it out, it just take some more expensive equipments

        no bad jokes intended, but the russians did it
      • Re:First, and... (Score:3, Informative)

        by Woody77 ( 118089 )
        spread-specturm over power lines has been proven to be a bad idea.

        It works, IFF the impedance across the frequency range that you're using stays the same, or you have the ability to react to the real-time changes in impedance at different frequencies due to motor start-ups, shut-downs, and who's got what on.

        The cable wiring is terminated, and is a bus that's designed to carry data. It's the obivous choice.

        Broadband over powerlines is only usefull for getting lots of attention from investors (who just se
    • Re:First, and... (Score:3, Insightful)

      by BoldAC ( 735721 )
      What the heck? I know St. Louis-based Ameren has been testing this for over a year. []

      I have seen a lot of data and reports on the interference problems which I think we all expected. However, I have not seen anything that this would be actually dangerous. Surely with the testing somebody would have noticed if people were getting zapped.

      I would like to see some data before labelling this as potentially dangerous to one's health.

  • 3rd world?!? (Score:5, Insightful)

    by prufrax ( 521403 ) <prufrax@blueyon[ ] ['der' in gap]> on Monday January 19, 2004 @11:08AM (#8020806)
    How can broadband over powerlines be a solution for the 3rd world? Surely you need most people connected to mains power first!

    • Re:3rd world?!? (Score:4, Insightful)

      by grub ( 11606 ) <> on Monday January 19, 2004 @11:18AM (#8020902) Homepage Journal


      Considering that they have yet to get power to so many of these areas, wouldn't it be wise to run fiber optic at the same time as they run new powerlines? The fiber could handle all their telecom and network traffic. Even TV, etc.
      • Re:3rd world?!? (Score:2, Insightful)

        by 77Punker ( 673758 )
        Right on! Furthermore, when these people have power, they still won't have computers. Even if they got computers, they'd have bigger problems on their mind.
      • I think that might be to expensive in fiber. Plus people might start to harvest the fiber for resale. I would rather use a separate cupperline.

        • Re:3rd world?!? (Score:3, Informative)

          by DukeyToo ( 681226 )
          Actually, copper cable theft is a huge problem in some developing countries (South Africa for instance). It is stolen and melted down again for resale. The 2nd-hand market for mass quantities of fiber is not quite as simple.
      • by Valdrax ( 32670 ) on Monday January 19, 2004 @12:37PM (#8021649)
        Considering that they have yet to get power to so many of these areas, wouldn't it be wise to run fiber optic at the same time as they run new powerlines?

        Oh, how Insightful. I mean, when wiring the third world, obviously money is no problem!

        Reality check -- the reason why this is suggested as a solution for the third world is that all they have to do is just run the power cables instead of running the power cables and some other cabling system for phone, TV, and internet. We are talking about people who current can't even afford to run the power cables, much less fiber optic cables too.
        • by iabervon ( 1971 ) on Monday January 19, 2004 @02:22PM (#8022774) Homepage Journal
          Wires are really cheap, compared with the cost of putting them somewhere they'll survive. It costs a huge amount of money to run a bundle of wires somewhere. But that splits into the huge cost of running a bundle of cables (including protecting them from the elements and such), and the small cost of the bundle of cables you're running. Broadband over power lines makes some sense if you already have a power cable coming to your house but don't have broadband; you can avoid running another bundle. But if you have to run a bundle, making it a big bundle isn't much more expensive than running a small bundle.
      • wouldn't it be wise to run fiber optic at the same time as they run new powerlines?

        Why bother with the power lines at all, just run the fiber cables, then set up a MPLampS network (RFC3251 [])

    • Re:3rd world?!? (Score:4, Informative)

      by AmigaAvenger ( 210519 ) on Monday January 19, 2004 @11:20AM (#8020923) Journal
      That wouldn't solve the problem, HF interference doesn't exactly stop when it hits the border of a country, it is a worldwide problem.
    • Re:3rd world?!? (Score:2, Informative)

      This is exactly why the dangers of this potential connectivity option are much less hazardous than some would lead you to believe. They aren't talking about running data over every power-line in every building in Atlanta. The main areas I see this being used consist of rural areas and developing countries (when running power lines, why not run inet lines too?). These areas aren't going to have much stuff that causes/recieves interference.
      • Re:3rd world?!? (Score:2, Insightful)

        by Nate B. ( 2907 )
        As one who lives in a rural area, I won't my breath.

        Anyone remotely familiar with technology should know by now that rollouts move from the population centers outward. The simple fact is that there is too much cost involved in BPL for it too start in rural areas.

        If anyone seriously believes otherwise, then I have a bridge to sell you.

        - Nate >>
    • Re:3rd world?!? (Score:3, Insightful)

      by vidnet ( 580068 )
      You're underestimating 3rd world countries. When National Geographic shows people living in trees or mud huds, it's because they document tribal people, not because it's representative of the population. 3rd world countries have buildings, cities and electricity like other places, only perhaps a bit less of them.
  • by PatrickThomson ( 712694 ) on Monday January 19, 2004 @11:09AM (#8020818)
    Oh great, now a slashdotting will take out all the power and aircraft in a hundred mile radius
  • Going both ways (Score:5, Interesting)

    by Anonymous Coward on Monday January 19, 2004 @11:10AM (#8020826)
    Do note that the problems of interference goes both ways: broadband over powerlines will jam HF communications (including emergency services some places). But at the same time a HF jammer or a HF over-the-horizon radar will jam broadband over powerlines.

    HF being global means a jammer in the Pacific can take out broadband in Europe.
  • This isn't news... (Score:5, Informative)

    by Jay Maynard ( 54798 ) on Monday January 19, 2004 @11:10AM (#8020827) Homepage
    ...well, mostly. The hazards of RF exposure are controversial at best, with widely varying opinions in the medical community and no real, controlled studies. It's pretty certain, though, that at the low HF frequencies that the BPL folks are proposing, the effects of exposures to a few watts are pretty minimal.

    This doesn't mean that BPL is a good idea. As the ARRL (which stands for American Radio Relay League) correctly points out - and has been covered on Slashdot before - BPL is a disaster for HF radio communications. Government agencies are weighing in strongly against it. I doubt it'll see the light of day in widespread use in the US.
    • We really don't lack for communications infastructure. Between our huge telephone and cable networks, and growing amount of fibre thereof, we are doing fine. The majority of the problem with getting broadband to end users comes from stupidity and/or anti-competitive behaviour on the part of cable and phone companies, not lack of infastructure to carry the data. Maybe in developing nations there is more benefit, but I kind of doubt it.
    • I think you are sorely mistaken. Ask people in the radio business what strong RF will do to you. Ask how common cancer among those that work with transmitters and tower climbers is.

      There is no debate about what strong RF signals will do. There might be room for argument about what low levels of RF will do.

      Just as swallowing a teaspoon of Mercury every morning would be just plain dumb, eating fish with small amounts might never be a problem in a grown adult for their entire life.
  • by Eric S Rayrnond ( 739458 ) on Monday January 19, 2004 @11:11AM (#8020831) Homepage
    HF radio is *the* communication medium for many life-critical situations. It is the only affordable communication line for many NGOs operating in third world countries, and HF equipment is much easier to setup and more rubust than satellite equipment.

    Until now, the HF spectrum has been carefully regulated to avoid harmful interference. It is just not acceptable to sacrifice it simply to get a cheaper Internet access. There are a good set of broadband technologies available which almost do not interfere with HF users.

    Let's hope politicians don't wait to do anything until a true emergency happens...
    • by Zondar ( 32904 ) on Monday January 19, 2004 @11:18AM (#8020901)
      From the article, it appears the Japanese already have decided to kill this system. ws /jn0208.htm

      Maybe our lawmakers could have their aides read up on why?
    • Good points Eric, as always.

      One analogy that hasn't been made is to that of light pollution.
      RF and light are just at different points of the spectrum.
      While nobody doubts the value of having light delivered over electric power lines, we are still struggling with the effects of light pollution on astronomy (both professional and amateur).

      Let's not extend the pollution problem down the spectrum to HF radio!
    • by ZPO ( 465615 ) on Monday January 19, 2004 @02:27PM (#8022825)
      Its also the key backup comms network medium in the US for a little tiny organization known as FEMA (Federal Emergency Management Agency) - yes I'm being facetious about the "little tiny" part.

      FEMA submitted comments to the FCC Notice of Inquiry that pretty much say "if you do this you will disrupt official government communications affecting the health and safety of US citizens". The NTIA didn't like it much either.

      I'd say there will be some trials conducted with FEMA and NTIA watching very closely. The first time it increases the noise floor in their receivers 1-2dB BPL will be a dead issue in the US.
  • Down already? (Score:4, Informative)

    by CaptainAlbert ( 162776 ) on Monday January 19, 2004 @11:11AM (#8020832) Homepage
    Seems to be Slashdotted already, even though I'm seeing 0 comments @ -1...

    Then again, I didn't think anyone really believed this, did they? I mean, any first-year EE student can tell you that mains cable is no good for signalling on, even at modest frequencies. Bah.
    • any first-year EE student can tell you that mains cable is no good for signalling on, even at modest frequencies.

      So if it's no good for signalling on, why are there commercially deployed Broadband over Power Line projects in mainland Europe and Commercial trials [] in Scotland and England offering 1Mb symmetrical connections.

  • by rharkins ( 307487 ) * on Monday January 19, 2004 @11:11AM (#8020833)
    Having an amateur radio antenna is like a lightning rod for neighborhood electronics problems. I've not transmitted for a couple of years now, but that has not stopped neighbors from blaming me for every glitch that occurs with their electronics. I can imagine what will happen if I key up my transmitter and disrupt every internet connection for a couple of miles....
  • Wonderful.... not (Score:4, Interesting)

    by Arimus ( 198136 ) on Monday January 19, 2004 @11:11AM (#8020836)
    Oh goody so now the power companies will have even more control as they blat out most LF/HF wireless within a certain distance of their transmission lines (or should that be antena lines now?)...

    Not to mention won't people who choose not to receive broadband via power still be able to tap into the transmission signal and so monitor other peoples traffic easier than trying to splice into the fiber backbone (oh hang on.... wonder if the gov't might not be keen for this very reason)...
  • I don't even want to -think- about what happens when the vacuum cleaner gets switched on!
    • I don't even want to -think- about what happens when the vacuum cleaner gets switched on!

      1. You have the equivalent of a Windows machine online.
      2. In case you're Finnish, insert a lame joke about downloading [] (here the verb for vacuuming is slang for downloading).
      3. Profit!
  • Laugh Test (Score:5, Funny)

    by Detritus ( 11846 ) on Monday January 19, 2004 @11:14AM (#8020863) Homepage
    How did BPL ever get past the laugh test?

    "Let's put something that looks like high-power broadband RF noise on long, unshielded, untwisted power lines, suspended in the air, otherwise known as antennas."

    • Re:Laugh Test (Score:3, Interesting)

      by moonbender ( 547943 )
      It's considered an option here in Germany, although DSL is now widely available and seemingly has basically killed demand for BPL. However take note that if I recall correctly it was considered a means to connect the "last mile" not in rural but in urban areas. Power lines suspended in the air are virtually unheard of in German cities as far as I know. The maximum length of data carrying wire was less than a few kilometres - I assume it ended at the nearest node in the electricity grid, similar to the way D
      • The problem is that as a rough approximation, any wire a quarter wavelength or longer can be an effective antenna. In the HF band (3-30 MHz), that's anywhere from 25 meters down to 2.5 meters. It doesn't take a very long wire to be an effective radiator, plus you also have to consider the length of the electrical wiring inside the structure.
    • Re:Laugh Test (Score:3, Insightful)

      by MarkusQ ( 450076 )

      We use separate pipes for drinking water and sewage.

      We use separate bags for produce and cleaning suplies.

      We have separate tanks for fuel and coolant.

      Who on earth thinks that sending power and data on the same lines is a Good Idea?

      -- MarkusQ

    • How did BPL ever get past the laugh test?

      While I am not particularly an advocate of BPL, there have been a number of successful trials in different parts of the world. IMO (I do technology assessment work professionally from time-to-time), the technology lends itself more to building local access networks than to long-haul transmission. Also, power network architectures in Europe and South America are better suited to such applications than North American architecture (an issue of the number of house

  • by CdBee ( 742846 ) on Monday January 19, 2004 @11:14AM (#8020869)
    My grandfather was an air-crash investigator, and once investigated a european crash (May have been Switzerland in around 1970, apologies, I don't have any details) in which an airliner had apparently tried to land on the side of a mountain. It was proved that the accident happened due to the local electricity generating grid using high frequency modulation to carry messages over power lines. The chosen frequency was a close enough match to the Instrument Landing System on the aircraft to cause it to engage. I hope modern airliners have better ILS.....
    • would have had to be switched on by the pilots.

      This story doesn't pass the smell test, or would you have us believe that planes run the risk of their instrument landing systems just "switching on" and attempting to land the plane automatically every time they pass an airport with ILS aids?
      • Unfortunately the smell test you speak of would pass the test. The ILS doesn't "Land" the plane, anymore than GPS would, it is simply a navigational aid which tells a pilot under instrument conditions (i.e. can't see well) where the runway is. If you remember this occurs in the Bruce Willis movie "Die Hard 2: Die Harder" where the terrorist reset the "ground level" on the ILS, and the pilots who were landing in the fog/snow and couldn't see the ground, fly the plane into the ground (manually but they "see"
    • Frequencies are wrong for ILS which runs adjacent to the VHF comm band, more or less.

      Far more likely, was an IFR NDB approach where they were trying to use the NDB to avoid the mountain, unfortunately they managed to avoid the interfering power lines instead, thus hitting the mountain..

      NBD freqs are in the 200 to 500 khz range which is adjacent to some of the signalling done in the sub 200 Khz range.
  • by robslimo ( 587196 ) on Monday January 19, 2004 @11:15AM (#8020873) Homepage Journal
    Hams are more concerned about the interference issue than the health risks, and rightly so. The potential health hazards created by modulating the power lines should be minimal, assuming the level of modulation is kept reasonably low.

    The interference caused to more traditional RF communications is likely to be significant because you are, in effect, stringing miles and miles of antenae across the countryside. The best bet might be to modulate on bands that are presently home to digital communication and in coordination with those present modulation schemes such that they don't interfere with each other.

    I suspect the whole issue may be moot, as I doubt that BPL will ever see a largescale rollout for other technical reasons besides these.

  • Here in Spain (Score:5, Informative)

    by octal666 ( 668007 ) on Monday January 19, 2004 @11:16AM (#8020885)
    That is in South Europe, just in case anyone doesn't know, we have broad-band over many companies, but main power-line distributor, Iberdrola, is now starting to offer this service with lower prices than other operators. I was thinking to switch to them since they offer lower prices and better service, and they have even run a test program over a few months in the city of Zaragoza and near country area with no known problems, I'm surprised to see that news here.
    • Re:Here in Spain (Score:2, Informative)

      by zoney_ie ( 740061 )
      They may not be using power lines, it might just be extra fiber-optics alongside the power lines...

      Certainly that's the case here in Ireland - ESB (Electricity Supply Board) hope to offer broadband soon by piggy-backing fiber on the transmission network.

      The ESB has also done small-scale tests of broadband over the powerlines themselves. The radio amateurs were up in arms. I think I heard that the ESB may have been committing an illegal act in causing interference.

      I don't know what the results of the test
      • Trouble in Spain (Score:2, Informative)

        by wsanders ( 114993 )
        No matter where in the world you go, BPL/PLC is trouble: The URE (Spain's ARRL equivalent) has documented interferece in Zaragoza - they have a rather pathectic web site with no functional content - one can find it by googling - but I quote the PDF document at e uronews1103.pdf,

        "About PLC, a strong movement against it has been started in Spain, led by the Union de
        Radioaficionados de Espana (URE).
        Accurate measurements done in Zaragoza have demonstrated the h
  • by kinnell ( 607819 ) on Monday January 19, 2004 @11:16AM (#8020887)
    Imagine being fried by a stray IP packet
  • Solution? (Score:4, Interesting)

    by sameerdesai ( 654894 ) on Monday January 19, 2004 @11:17AM (#8020891)
    I know most of the big cities have their power lines underground (at least mine did). The broadband company took it to their challenge to even put the broadband cables underground. I guess that could provide sufficient shield along with the shielding on the cable itself. Now the question is cost of doing this over the entire country, which I have no clue. Again I am just curious as to how will these two cable interact because it is failing my general electromagnetic knowledge.
    • Re:Solution? (Score:3, Insightful)

      by Zondar ( 32904 )
      What about those spider-web of antennae known as house wiring?

      You can't realistically shield everything in the current state of the power distribution network...
      • Gimme a break (Score:3, Informative)

        by siskbc ( 598067 )
        What about those spider-web of antennae known as house wiring?

        You do anything to your home grid serious enough to pose an RF risk to humans, and you'll blow the hell out of your breaker box.

        Come on. Next cell phones really do cause cancer, I bet.

    • Large currents can't be efficiently sent over long distances underground. The ground contains moisture, and acts as both a giant capacitor plate, and a giant inductor.

      When alternating current passes through a power line, it creates an alternating magnetic field which is concentric with the power line. This field induces AC currents to flow in any nearby conductor. If the cable is buried inside a conductor, such as moist earth, the amount of energy sapped from the cable becomes extremely large.

      So basical

    • Now the question is cost of doing this over the entire country, which I have no clue.

      If you're going to dig up the entire country to bury power lines, why not just run fiber while you're at it ? The additional costs would be minor and fiber is essentially "future proof" and would provide all the bandwidth needed well into the future. BPL has no higher bandwidth migration path and it's flawed technology.
  • by Saven Marek ( 739395 ) on Monday January 19, 2004 @11:18AM (#8020905)
    And quite dangerous.

    I mean, really, who expects this to work []
  • Support (Score:2, Funny)

    by savagedome ( 742194 )
    Ever see those medicine commercials where the human body is struck by lightning.
    Now, a different wave of support questions.

    Support Monkey: Sir, do you see lighting like things on your computer? Sir... Sir...
    (To his colleague monkey) Looks like he hung up
  • Suggested before (Score:3, Informative)

    by PhatKat ( 78180 ) on Monday January 19, 2004 @11:20AM (#8020920) Homepage
    The idea of transferring data over power lines has been suggested before... but at least in the case reported in wired of Nov. 2001, it didn't work--despite what everone wanted to believe.

    the article [].
  • by Anonymous Coward
    ...and is a threat to their broadband over oil pipeline plans.
  • Don't use RF (Score:5, Interesting)

    by Hellkitten ( 574820 ) on Monday January 19, 2004 @11:24AM (#8020954)

    What some power companies here (norway) have done is to use a special kind of machine (it looks like a really clever invention) that "spins" fibre optic cable(s) around high voltage power lines. This doesn't work for buried power cables, ofcourse. This technique gives several advantages: Cheap, the cost is the cable and a helicopter, no digging, no new cable masts, no buying right of way. Security (I'd think twice before trying to mess with a cable wrapped around a high voltage line :D ). And since light won't be disturbed by the magnetic fields generated by the current there is no need to worry about power and data interfering with each other

    • Do you have any links to this technology?
      BTW, Faraday effect WILL change the polarization state of the light.
    • Re:Don't use RF (Score:4, Interesting)

      by carndearg ( 696084 ) on Monday January 19, 2004 @11:42AM (#8021103) Homepage Journal
      And since light won't be disturbed by the magnetic fields generated by the current

      I remember reading a very interesting article years ago, may have been 1980s, about a device for measuring leakage currents in metal pylons(towers) on very high voltage power transmission lines. It was a fibre optic device, you wrapped it round the base of the pylon and measured the amount of light you could transmit through it. It seems that the magenetic field generated by the leakage current affected the refractive index of the fibre, varying the amount of light that could escape, thus you could non-intrusively measure the current by measuring the amount of light you lost.

      Of course, they probably used a special fibre optic material with the right properties, but I have often wondered how they get round this with the fibre-on-powerline systems. Sadly I cant find anything about it on the www.

      • Re:Don't use RF (Score:2, Interesting)

        by nexthec ( 31732 )
        Not quite what you are talking about, but NxtPhase [] makes optical voltage and current transformers for measurment of high voltages lines using the Faraday effect. Quite cool, a grad student here at Uof I has told me he can make one for a couple of hundered ;->
  • FAQ (Score:5, Informative)

    by Goody ( 23843 ) on Monday January 19, 2004 @11:32AM (#8021011) Journal
    There's isn't a biological threat from BPL, but the interference issues are very real.

    Here's a BPL and Amateur Radio FAQ [].
  • I wish (Score:2, Insightful)

    by Anonymous Coward
    I wish we would stop throwing all sorts of half-assed technologies at the problem. Simply dig a hole, put some fiber in it and drown people with bandwidth. Yeah, it's going to cost more and it'll take longer, but it will also LAST us longer. I am typing this on a collaboratively installed 100 MBit/s ethernet which is attached to other similar networks via a city-wide gigabit backbone. We did a lot of digging and paid thousands, but it was so worth it.
  • RF Hazard? (Score:2, Informative)

    by fatboy ( 6851 ) *
    The hazards include exceeding MPE (maximum permissable exposure), RF burns, and disrupting the HF bands of radio.

    Um, you just made that up didn't you? I have never seen anyone, including W1RFI (Ed Hare), state that there was any type of RF hazard from BPL. It does pose a serious interference problem for anyone using HF, but not a health risk.

  • by TEB ( 566487 ) on Monday January 19, 2004 @11:39AM (#8021073)
    The hazards of RF exposure are still being debated. Hazards from BPL would need years of study. That being said people are probably at more risk from intentional radiators like WiFi points. This is due to the way the body absorbs RF. The absorbtion is a function of the wavelength of the RF and the size of the human body. I don't remember the exact data but the shorter the wavelength the better the absorbtion. This does have some exceptions but I do remember a strong absorbtion around the 1Ghz range.
    The interference problem is the greater of the two. Yes it will interfere with radio communications but the interference will be worse for BPL. Aircraft have the potential to cause interference over a wide area due to their altitude, but the tranmitter is relatively low power. The real problems will start when a ham operator can't talk to his buddy 20 miles away. They get tired of the interference so they kick in the linear amplifiers. Since the max leagal power for most of the bands is 1500 watts they have the potential to take out BPL in a very large area.
  • by IGnatius T Foobar ( 4328 ) on Monday January 19, 2004 @11:44AM (#8021121) Homepage Journal
    Here in the New York area, the power company (Con Edison) has a broadband network. You know how they did it?

    They used the fact that they already own the poles, to string up their own fiber optic cable.

    This, to me, is the primary indication that broadband over power lines just isn't going to happen. When even the power company doesn't believe in it, you know it's a dud.
  • by carndearg ( 696084 ) on Monday January 19, 2004 @11:50AM (#8021188) Homepage Journal
    As I understood it from the last time this was mooted here in the UK we were going to see this as a last mile solution from your local distribution transformer to your home. The substation would get its internet connection via fibre and redistribute it in much the same way as low power mains intercom and network products work, with very low range. In the UK context this would be at the 11kv-to-240v transformer which usually serves a street of houses.

    Am I right in gathering that the systems described here use high power HF on powerlines to distribute over much longer distances than this?

    • There are three powerline communications applications in use:

      1. Broadband over power line systems described here are all last-mile access systems for use on medium voltage (approx 1 kV to 35 kV) and low voltage (under 1 kV). These are for linking internet users to an ISP (either the power utility or someone partnering with the utility). These are broadband speed systems.

      2. In home power line broadband for linking computers and other devices within the home over short distance. These are all low voltage
  • Here in the mid-atlantic region, AEP has most of their power grid strung with fiber alongside the power lines. I have a friend who works in a local office and he used to amaze me with the bandwith of their network. AEP uses the fiber for their company data and voice networks as well as leasing the lines out.

  • Sounds like a file sharing organization! How could they be against any kind of broadband! ;-)
  • by Psx29 ( 538840 )
    Does anyone know if the same basic principles used in transmission of broadband over powerlines are employed in those LANs you can connect to any power outlet?
    • Re:LANs (Score:2, Informative)

      by Anonymous Coward
      Same basic ideas, spread spectrum RF modulation being stuck onto the power lines. The outlet methods you mention use much lower power than would be required here. They also are limited by comparison in bandwidth they could offer.
  • by DARKFORCE123 ( 525408 ) on Monday January 19, 2004 @12:36PM (#8021636)
    As with any other transmission medium , someone will try to adjust his/her upload/download caps.

    More voltage means more bandwidth!

    Let me just up the wattage a little bit more!

    Ahh! Ahh!


  • by bgelb ( 623168 ) on Monday January 19, 2004 @12:51PM (#8021793)

    I'm not quite so ready to believe the health-realated concerns, but the interference problems that will result from an implementation of BPL are very real. I've seen a demonstration of BPL's interference at a local hamfest here in the Washington, DC area (For those interested, AMRAD will also be giving a presentation at the DC area Winterfest [] hamfest in February). BPL makes a lot of noise on an HF receiver, across the entire tuning range! But what is potentially even worse is that a relatively small amount of power (I believe they gave the example of 10 watts into a dipole at reasonable proximity) is enough to cause a link to fail.

    Undoubtedly, a ham radio operator's neighbors, and perhaps the power company, will put a lot of pressure on him to cease operating a ham radio. This is totally backwards! Let's revisit the Part 15 rules for a minute - the regulations that apply to unlicensed services, including BPL. It says that an unlicensed device MAY NOT cause harmful interference to a licensed service but an unlicensed device must accept any harmful interference received.

    This basically means that the burden for resolving any interference problem is on the head of the unlicensed service, in this case, the power company - at least in theory. I have a hard time believing it will play out this way though. In fact, when the FCC asked for comments on a notice of inquiry with regards to relaxing part 15 standards, many power companies claimed that NO INTERFERENCE PROBLEM EXISTS, and it is up to other users to PROOVE it, before they should be required to act on it. This is a total reversal of the roles established by Part 15! And that is leaving aside the fact that there are several studies done by hams, including a very good one from AMRAD [], that do proove, both empiracally and mathematically, the interference threat. BPL promoters, including the heads at the FCC, have turned a blind eye.

    HF radio is used to provide long-distance communications during disasters by many groups, including ham radio organizations, and FEMA. (FEMA has recently weighed in [] on the debate) It also carries shortwave broadcast from other countries, which would be sqaushed by interference.

    It does not make sense that the FCC should allow an unlicensed user to render this huge chunk of spectrum totally useless to it's intended users. It's selfish and shortsighted.

    Please write your congressperson. Make them aware of the problems BPL could bring.

    • by Zondar ( 32904 ) on Monday January 19, 2004 @01:10PM (#8021996)
      Loved this section from the FEMA document...

      "As pointed out in numerous stories and reports from countries where BPL implementations have been tested, the unavoidable radiation from power lines and associated modems raises noise floor limits to an unacceptable level. This interference will severely impair FEMA's mission-essential HF radio operations in areas serviced by BPL technology. Tests have shown that in order for licensed transmitters to compensate
      for this noise level, there would have to be an increase in the signal level on the order of

      6. FNARS utilizes transmitters that range from 1 kW to 10 kW in output power. An
      increase in power of +30 dB to offset the increased noise floor would require a 10 kW
      station to increase power output to 1 MW."

      And the 30db figure came from tests in Finland, where they also shot down BPL.

      FEMA's quotes: See Gerhard Latzin, "PLC for the present rejected by Finnish Telecommunication Minister", 25 May
      2001, published on the Internet at; Ministry of Public
      Management, Home Affairs, Posts and Telecommunications, Japan, "Announcement of report by Power
      Line Communication Study Group" 9 August 2002, published on the Internet at s/Te lecommunications/news020809_3.html; Koos
      Fockens, "PLC Measurements", 7 May 2002, published on the Internet at Repo rt.pdf; Mel Maundrell, "Concerns for the continued Military Use of HF over the Potential Increases to the Background Noise Level", 11 January 2002, published on the Internet at nts/dera.pdf

      And one other gem section:

      "Currently, there is no alternative to HF radio
      communications in terms of meeting national security and emergency preparedness
      requirements at the national, state and local levels.
      10. FNARS HF radio stations are normally located in residential areas that would be
      serviced by Power Line Communication (PLC) systems. FEMA also utilizes HF radio
      stations from other Government programs, including the Military Affiliate Radio System
      (MARS), the US Air Force Auxiliary - Civil Air Patrol (CAP), and the Radio Amateur
      Civil Emergency Service (RACES), which are similarly situated. The interference from
      PLC would render these essential communications services useless.
      2002, published on the Internet at nts/dera.pdf
  • Once upon a time... (Score:3, Informative)

    by Maresi ( 456339 ) on Monday January 19, 2004 @01:16PM (#8022076) Homepage
    there was an emergency training in Linz/Austria.
    The training was designed to simulate an major accident (if I remember it correct, it was an explosion of a chemical plant) and to practice the coordination of firefighters, the Red Cross, the police and several other organisations.
    Linz, wich has some 18,000 households, is "Austrias powerline city", wich means, it has about 900 working powerline installations.
    But these 900 installed plc units were enough to completly suppress the radio units used by some of the participants (e.g. the Red Cross).
    These teams had to abandon the training, since communication was near impossible!
    Imagine an real accident: No Red Cross or other ambulance teams! (In Austria, the Red Cross still has the major peace of the ambulance-business-pie).

    Id rather get hurt on the countryside!

  • by w1rfi ( 641683 ) on Monday January 19, 2004 @02:03PM (#8022585) Homepage
    The FCC has limits to human exposure to RF energy, but broadband over power line that operates at the FCC limits of 30 uV/m at 30 meters distance cannot, under any circumstances, exceed those RF safety standards. On 30-300 MHz, the part of the spectrum with the most stringent exposure limits, the exposure level is at about 27.5 volts/meter -- a level about 120 dB higher than the levels permitted by Part 15 to unlicensed emitters such as BPL. Expressed in power, the BPL systems are permitted to operate at a level that is 1/1,000,000,000,000 of the FCC's exposure standards. The risk to broadband over power lines is that the levels are strong enough to cause harmful interfernce. As a secondary issue, at least one system has been demonstrated to be susceptible to interference from amateur radio and presumably other HF operation. The RF levels of BPL systems are, however, nowhere near the levels that could exceed the RF-exposure limits. Ed Hare,

  • Piping RF onto the power transmission lines is a hair-brained idea put forth by the same crowd that brought us power brokering. Oh boy, that sure has been a panacea. Not! The Hams are up in arms for good reason. If this is deployed, we'll have lots of long wire antennas bristling with hash. Why is the FCC even considering such a cockamaimy notion? Michael Powell

  • I live in Manassas, VA and the city gov't has some lash-up with some company (prospect st. I think) to deliver this service. Out of curiosity I filled out an interest form a month ago and haven't heard back. I know they had announced general availability on Jan 1 but nobody I talk to has actually seen it installed beyond the small pilot test they did. I'm pretty sure it won't go anywhere but figured I would keep my options open.

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