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Broadband Over Power Lines vs. Radio Relayers
amaiman writes "Recently, broadband Internet access has been increasing around the country. These broadband signals, while providing Internet access to remote communities that would normally not be able to receive broadband, are causing enormous interference to the radio spectrum. This article details some of the problems, and a video available on the American Radio Relay League's (ARRL) site shows exactly how much interference the broadband power lines can cause. Detailed information is also available on the ARRL site."
Look at some of the backers of the anti blp group and you will find that some of them stand to lose if bpl takes off. It isn't just the pro bpl side playing games.
Art Bell (coasttocoastam.com) has a big beef against BOP (Broadband Over Power) for obvious reasons.
Life is not for the lazy.
Articles about BPL that get technical often bring up comparisons between how it works in the US vs. Europe. For various historical/technical evolution reasons, including population densities, the two sides of the pond have much different concentrations of number of users per power transformer, and supposedly the technology makes a lot more economic sense in Europe. In the US, one of the more interesting markets is rural access, where distances are too long for DSL and cable TV isn't very common - satellite's an obvious alternative, but satellite latency is annoying. Non-Amish farmers have tended to be fairly wired for a long time - the commodities and futures markets have a major impact on how you can get the best price for your crops, and even old modems and Apple IIs were good enough to get trading information and text-based weather reports, but more bandwidth is always better.
But the other obvious market is that it's another wired or near-wired access method to get bits to your house, besides the Phone Companies and cable modems, which means it increases competition for the phone business as well as data business. Power companies already have a certain amount of potential simply from owning right-of-way, though sometimes the phone companies own the poles, and state Public Utility Commission regulators often create all kinds of strange rulings about who can do what with the shared assets (a problem cable tv companies have had, especially when they want to sell bandwidth on the fibers they run in shared right-of-way.)
Bill Stewart
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Note that it's only a *very* small subset of the ham community that's even considering deliberately jamming BPL. Most hams are considerate to a fault, and wouldn't retaliate like that.
But for now, if you need to use 1500 watts to make a contact, it's legal for a ham to use 1500 watts to make that contact (on most bands), even if it causes problems for BPL. The law says you need to use the minimum amount of power to get the job done, and most hams do that. But if you need 1500 watts to get the job done, then you can do that.
(For the record, I'm AD5RH. And I don't have any equipment capable of putting out over 200 watts.)
Look out your window - every amateur radio operator who lives within a couple hundred yards of a powerline will be affected. Not only that, but, according the the ARRL site, rural emergency radio communications (Fire Department, Ambulance, etc) will also be affected. Don't forget, also, that the frequencies that we're talking about are used by amateurs to provide emergency communications during natural disasters, health and welfare traffic, as well as comms during public events like marathons, bike races, parades, etc.
BTW, it's not a matter of pumping up the transmit power either. It's on the receive where BPL causes the biggest problems. You're already trying to listen to a whisper in crowd, and BPL is like an obnoxious car salesman with a bullhorn.
If you can pick up these boxes with these tools, then these boxes are not BPL., unless they're some sort of bridge between BPL and WiFi, or can be managed via WiFi or something?
Aha ... google to the rescue!
So they are bridges. Seems an odd way to do it though -- BPL CAN go all the way into the house (that's part of why people like it), so why are they using WiFi for that? If all they're doing is putting APs in each neighborhood, why use BPL at all? Just run standard cox or fiber optics to each AP.Shortwave radio communication over any long distance (commercial, military and hobbyist) often deals with weak signals. Each broadband power line adds to the background noise cumulatively raising the problem. One power line won't trash your TV signal (unless you are very close), but each one adds noise until all you have is snow.
Its like people talking in the background - a couple of people don't do much harm but when you try and talk across a room full of quietly talking people two things happen
1. The cumulative background noise reduces the signal
2. You turn the volume up (as the amateur radio people will have to and although entitled too don't wish too because it causes other users problems)
When you turnt he volume up, they all have to talk louder, so you get a fight between high and higher BPL power (to avoid radio wiping out internet, and higher and higher radio power for the same reason). At which point nobody can communicate usefully and lots of third parties are harmed.
HF interference isn't just an amateur radio problem either - you might well find you get 802.11 dead zones if you are near a power line using it. You may not be able to use radio controlled toys in an area with too many power lines and so on. Finally HF is essential to things like flying medical services and some rural communcation systems.
It all gets quite messy when this happens because good radio practice is the lowest possible power. The lower the power you can use the more people can use the same frequency. If everyone has to use 1KW then you'll get a lot less frequencies.
I'd also say their description of the FCC is in tune with its historical decision making - just look at the monopolisation of US commercial radio and the continued unneccessary exclusion of most small transmitters which could exist and other countries have proved are not a problem. Of course BPL background noise might well wipe out the scope for very low power radio stations too.
BTW: BPL trials in the UK (way before the US) were shelved for several reasons but intereference was a big one.
It shouldn't be insoluble - one nice property of radio is that if you can get the BPL encoding frequencies high enough then the interference problems become much less of an issue.
(PS: I defy you to find a radio astronomer who won't use expletives when asked abtut BPL..)
"And if very many hams do what you suggest the laws will be changed and those hams will lose their licenses and have to pay fines."
You forget that the FCC rules aren't run like regular laws. The FCC comes up with policies and procedures to follow, and the federal government's laws only state that if you want to participate, you go talk to the FCC and follow their judgements.
Remember too, that ham radio has been around for fifty years. Some very high profile people like Barry Goldwater have been ham radio operators. There might not be anyone of particular notoriety that stands out in the hobby right now, but there are well established lobbyist groups, a close-knit community, and usually willing to stand up for the priviledges granted to them. They won't just roll over.
The real fun will start as soon as a BPL installation jams an automated repeater, and that repeater's owner presses the FCC to fine the BPL owner, which under their rules they'd have to at least investigate.
Do not look into laser with remaining eye.
Fog, rain, snow, trees, and hills all "interfere" with lasers. Laser comms are great for parts of Arizona though. :-)
I just got an arrl newsletter telling all of their members to contact their congressmen and tell them what a bad idea this is. Apparently, according to ARRL research, broadband over powerlines causes significant interference not just in ham bands but across the spectrum. Although I havn't exactly looked at the research in detail, I can't see how the power companies could avoid interference. Powerlines aren't shielded, and for any reasonable bandwidth to be passed through the powerlines, the frequency would have to be high enough that a significant amount of power would have to be used. Unshielded wire is always agood antenna, and for some situations the best. Granted it won't be well tuned, but I've seen worse situations cause a lot of interference. My home is near high voltage power lines (read a large part of San Francisco's power) and even at 60hz, I get interfering harmonics all the way up into 10 meters. Avoiding electrical grid contamination is something every ham has fought with. Hopefully I'm wrong, but unless there is some way of preventing interference, this seems like one of those thngs that will be really good for pacbell and really bad for the rest of the wireless world.
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Because of cost. They're trying to use existing installations to do this, specifically avoiding running new wire. If they were going to install shielded cable, they may as well just put in coaxial or fiber.
As far as shielding power cables though, they don't do it because it's not effective, the shielding breaks down due to the elements, it's harder to diagnose a problem with the power grid, and probably a whole slew of other things.
Do not look into laser with remaining eye.
If you live in a urban/suburban area, look around you: how far can you get from any powerline? While it is true that the interference is subject to inverse-square and dies out rather quickly, if by the time you get out of range of one power line you are getting into the range of another it doesn't take much for 100s of square miles to be radio wastelands. What is the maximum distance you can ever be from a power line in New York City? Los Angeles? Washington, DC? Chicago?
If the g'vt kept the data on you that google does you'd better believe you'd be calling it "doing evil"
A very important yet often overlooked thing to keep in mind while thinking about "broadband over power lines," as I have already written countless times with little effect, is the very fact that it all has started as a scam. The idea has been introduced by Luke Stewart, a scam artist who has promised more than billion gigabits per second (sic) with his "Media Fusion" snake oil.
This scam and those billions gigabits per second was the only reason why "broadband over power lines" has been ever considered in the first place. See these links for sources and much more informative details and background.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
I have found a direct link to the article I was quoting in my previous post, The Electric Kool-Aid Bandwidth Test by Evan Ratliff. It is long but very interesting and enlightening. True eye opener. Enjoy.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
Aside from the fact that previous installations aren't shielded, even shielding new installs would be far more difficult/expensive than just running a dedicated line in parallel.
Think about it--powerlines are everywhere, and the hams use power to run their transmitters, and more importantly, their receivers. It doesn't take much for an interfering signal to get from the power cord to the antenna terminal. Sure, hams can up the power on their home rigs, but what about their portable and mobile equipment that has proved so important in providing communications during natural disasters, weather emergencies, and yes, even in in NY and DC on 9/11? The ham frequencies to which BPL causes interference are nicely nestled between AM and TV, so the average person isn't likely to experience the interference directly--which is what the FCC and the power companies are counting on. Nevertheless, low-power interference radiating even a short distance from power lines can render these frequencies useless for many (if not most) amateur operations. I've been an active ham for many years, and I can tell you the FCC has almost never been much help when it comes to interference TO amateur operations, but come out in force if someone complains about interference FROM an amateur station. It looks like we are going to be losing our only means of emergency long-distance communications that doesn't depend on an intact infrastructure. This is very significant in any major emergency. True, during a hurricane the power lines will likely be down, so there won't be any interference, but it's going to be difficult to encourage newcomers to get into a hobby that doesn't work 99.9% of the time. That's my .02 worth.
The ARRL just celebrated it's 90th anniversary. Ham radio was around before that.
Hmm, did I see you down at the World Trade Center site during 9/11 and the following weeks? Didn't think so. Us Ham radio operators (I came in from Connectucut) were down their providing communications in 24/hr shifts. I provided over 48 hours of service. If you were not so ignorant as to what we do and who we provide service for you wouldn't be so quick to open your mouth.
Now imagine there was some kind of full scale attack on the US where multiple cities were affected. Phones are out, cells are out (or like during 9/11 useless) forget the Internet and your lucky to even have electricity. Hams are no longer operating on HF because some short sited people, who are more concerned with their stock investments, got BPL pushed through. Who is going to provide not only local but long distance communications? You?
The interfering Iowa system is using Amperion BPL equipment. This uses HF BPL on the lines for a backbone, and then WiFi (802.11) for the "last hundred feet" from the pole to the home.
Tired of being "punished" by the Slashdot $rtbl since 2002. I'm now over at http://soylentnews.org/ .
For more information on the problems with BPL than you'd ever want, read the NTIA Notice of Proposed Rulemaking Comments and the Phase One Study.
Tired of being "punished" by the Slashdot $rtbl since 2002. I'm now over at http://soylentnews.org/ .
A very small set of bands:
h tm l
http://www.arrl.org/field/regulations/allocate.
If you add them all up, it's around 3 MHz total I think. Enough for one person to get 3Mbits/sec.
So what this should tell you is that there are lots of other users in the 0.5-30 MHz spectrum space. It's going to stomp on lots of services, not only Amateur Radio.
Amateur Radio is just a tiny user of this spectrum.
BTW, 0.5-30MHz is all the frequencies which we can reliably use for long distance communications. That is just under 30 MHz of bandwidth. Go look up how much bandwidth just ONE HDTV station takes up....
>most commercial and military communication in the
>US has moved to satellite; Only smaller services
>(in the west), third world countries, radio
>stations and HAM radio operators use HF
Actually, the U.S. military still makes *heavy* use of the HF portion of the radio spectrum - primary modes are SSB (long-distance voice communications) and ALE (a digital system for sending short messages and for analyzing the reliability of particular frequency). Emergency services, such as FEMA and the Red Cross, also make heavy use of 'shortwave' for their long-distance/emergency communications. FEMA even responded to the FCC's request for comments to argue against deploying BPL, apparently to no effect (which surprised me - i thought they'd pull more weight, seeing as the've been incorporated into the Department for Homeland Security)...
I am not a number - I am a free man!
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