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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."
But I thought that hams where saying that BPL would destroy radio communication for 100's of miles around? This video only shows the effect when they are very near the powerlines.
They also play word games by saying it is on the agenda at the FCC. On the agenda doesn't mean that they will approve it, it simply means they are looking at it.
Lastly, it doesn't help hams when hams say they will just pump out a 1kw signal to drownout the BPL signal, that action will simply result in the group with the most votes winning, and that isn't the hams.
... of why the FCC is so damned ineffective. I thought the FCC was commissioned to prevent just this sort of thing? Apparently these days it is only another government hypocricy that panders to the highest-paying lobby.
bash: rtfm: command not found
Art Bell (coasttocoastam.com) has a big beef against BOP (Broadband Over Power) for obvious reasons.
Life is not for the lazy.
This article is 4 months old. In March the power company Cinergy in Cincinnati started offering broadband over powerlines. I havn't heard much about that since then, I really would like to hear something about that. Is it still around? Is anyone using it? Are there any complaints?
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The latest RFC don't deal with broadband over power lines any more. It's been tried, and power companies have folded over this bet.
My own power company gave up and found it more efficient to simply lay TCP/IP fiber along the new power lines instead.
No, the new thing is not TCP/IP over electricity lines, but electricity over TCP/IP lines, as detailed in RFC3251.
On a previous project we used point to point optical /.ers?
units, I remember the output was only a few hundred milliwatts but we were p2ping 5Km or more in fair
visibility. Surely optical wavelenghs are not restricted and civillian versions of this sort of
optical tranciever are available? Someone has to line them up at installation, but its as easy as doing a microwave dish. I think a network of point to point laser trancievers would be ideal for remote raural coms in the out back and beyond. With this kind of power efficiency repeaters would easily run from solar cells. What think the
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
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
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..)
BPL has been tried in Germany by almost all major power companies, but they have basically given up on it. Reason: It does not work, plain and simple.
There are a few companies around that sell so called PLC-to-Ethernet adaptors you can plug into your power outlet to bridge floors or so, but they're not working either.
Testing has shown that the signal attenuation between two of these PLC adaptors is actually higher than the free space attenuation - so these adaptors would work just as good or even better if they were not connected to a power line at all :-)
I think BPL is basically a dead horse, and slashdot should stop beating it.
Thanks, Slashdot, for this article. One the cat is out of the bag, he won't go back in...so it's important that BPL gets ripped out when it fails (which it will...oh yes we have WAYS of making it fail. For instance, all BPL ISPs will be filtered at my firewall. And I am a licensed amateur, and will file an endless stream of takedown complaints to the FCC, as hams ARE the primary users of the bands in question). So, doing whatever it takes to delay any implementation, on a local level, is appropriate. It would be a good idea for municipalities to ban it.
There is only a fairly small frequency band in existence that can be used for inexpensive worldwide communication, and that is HF. The reason are more or less predictable Ionosphere layers that reflect radiowaves.
Under good conditions, you can transmit halfway across the world, with just 1-5 Watts of transmission power. The Amateur Radio community knows this as "QRP" operation, and it is quite popular. So, yes, even small amounts of HF noise will go a long way to interfere with shortwave communication.
20 years ago a sizable amount of communication was still being done by shortwave (HF) radio, and anybody thinking about poisioning large chunks of HF spectrum would've been declared a raving lunatic. Every kHz of HF spectrum was (and still is) a prized posession. Look up any frequency book from the 80's and you'll see that there wasn't a Hertz of HF spectrum unallocated, and it was (and still is) tightly controlled by international agreements. For large Radio stations (BBC, VOA), it is still the only way to connect to people in dictatorships and less advanced countries.
Today, 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. Of course, why would large power companies care about other countries or the BBC news ?
The HF spectrum is still the most valuable piece of electromagentic real estate there is in the World. Purposefully injecting additional noise into the band for no other reason than to save a few bucks is a terrible mistake and shows ignorance and recklessness on a staggering level.
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."
The ARRL just celebrated it's 90th anniversary. Ham radio was around before that.
Believe it or not but some of the best antenna and radio designs of the past 50 years have been by amature radio operators. They are also responsible for an inovative rocket payload system so that they could piggy back their sattelites behind larger commercial loads. This should be a surprise to no one. These amatures have been driven by the same motivations that has made open source software some of the best in the world: they love what they do. Amatures need dedicated radio bands so they can work in and test their desgins without interference from or to others. These dedicated bands need to all over the spectrum as each band has its own advantages and challenges. Of course not every amature radio operator is a designer. But like open source software developers, RF designers need users to provide feedback. Amature operators provide imporant feedback such as signal strength and quality, and distance between stations.
It is also nice to have public radio bands that are not controled by commercial interests, in much the same way that it is nice to have public parks. Free of commercial interests amature radio bands are free (as in beer) to use. More importantly amature radio bands can be used in new and innovative ways that commercial interests are not interested in supporting.
Unfortunately these public radio bands are not as easily accessible as public parks. Licences and tests aren't the problem. RF is fragile and proveing that you will use it responsibly is important. A big problem is, ironically, the ARRL.
The ARRL has fought so hard to protect their radio bands that they risk loseing everything. The ARRL has lost its relavence to the general public. Amature operators around the world have been extremely reluctant to change. The old amatures have always welcomed new amatures, but they haven't gone out of there way to find new amatures. There has always been a huge source of new amatures in the hacker community. The ARRL needs to do more encourage these hackers to become radio amatures.
The current structure and activities of the ARRL does not encourage new participation. Young radio hackers are not interested in DX competitions and making 10 second contacts to fill out a QSL card. Young hackers are not interested in making contact with some grumpy old guy half way around the world just to hear what ailments he has. (This is a far too common occurance.)
Young hackers are interested in making world wide, community based, digital networks. They are interesetd in freedom of speech and privacy issues. They want to use encryption. Many of the old amatures are affraid that the young hackers want to move in and change everything. This is only partly true. The hackers do want to change a few things, but they are also more then willing to work with the community. Look at groups such as Seattle Wireless. These guys are essentially rogue freebanders. The ARRL needs to modernize themselves and the FCC to turn these freebanders into licenced amatures.
If the ARRL and similar groups don't do more to encourage new participation there won't be amature radio in few decades time, because there won't be many amature radio operators left alive. The recent easing of licence and band restrictions will help, but much more needs to be done.
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....