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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.
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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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Here in Cedar Rapids IA, we already have it, i can go and see the units themselves mounted on the powerlines, and pick them up with kismet and netstumbler along glass road. Im a ham too, so i dont really care for this, they can find a better way to get broadband to everyone.
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
We had to make HF frequencies by hand! In the Snow! Uphill both ways!
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.
shield the cable (and obviously earth the shield)
that way nothing gets in, nothing gets out - everybody wins (exceept those who pay for the cable)
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."
Provideing a highspeed network to a rural area is a hard problem. There are few customers to offset the operating expenses.
A local start-up was working on a highspeed network for rural areas. It used HF in a licenced band so interferance would not have been an issue. Because the system used HF one tower could cover quite a large area. The speeds were not lightning fast but were faster then modems. I believe the project goal was just a little faster then sattelite.
Unfortunately the project was killed for two reasons. The first was patents. There are some (arguably obvious) patents that cover highspeed networks over HF. The patents owners were not interested in developing the technology themselves, rather they wanted to charge exhorbitant fees to licence the patents. Given enough money this issue could have been resolved, but when coupled with the second problem project was canceled. The second problem was lack of a market.
From the start the system was designed to serve sparsely populated rural areas. This system could not compete with DSL, cable or 802.11 based systems. The bandwidth was slower, and more the system was more expensive. The setup costs were high as a client station needed a good HF transciever and antenna. The service fees were high as the base stations were designed to only handle a few customers. The system had to be heavily optimized for rural areas in order to achieve the large distances required. The optimizations were such that it could not even be scaled back to compete in the quasi-rural suburban environments. The system was expensive. While an end customer might be willing to pay $1000 to setup a station, plus $100/month for highspeed no provider was willing to take the risk when a base tower could easily cost $100k just to install.
I suspect that highspeed of power lines is going to face similar challenges and suffer the same fate. The setup costs are deffinately lower, but the system is still faced with some of the same technical problems. Long distances cause more noise, which lowers bandwidth, which reduce the number of customers on a given segment. With fewer customers there is less chance of a profit.
Most of the HF bands are used for commercial purposes, some slots are allocated for limited private use (eg CB, remote control toys, 49Mhz walkie-talkies), and lots of it is used for emergency and longer ranger services where VHF/UHF simply won't do the job. This includes people like emergency services.
Amateur radio is probably more relevant now than since the 1940's. Its real reason for existance beyond the first uregulated days of "gee isnt this neat" was to provide a steady supply of wireless operators to draft in the event of a war. Its not the only reason but its a major reason it survived.
Alan
...for now, and I live out in the stix and don't have broadband,and I have certainly whined about it enough, but I STILL don't want anything that will mess up the radios. No SUH. I look at my radios as my ultimate backup communications tool. The telcos can go down, the internet can go down, the TV stations off air, cells can be jammed up-and I still have communication, and it's both ways commo if I want it. And you can get information in real time, from a variety of places all over the planet, with any normal multiband receiver and a chunk of scrap wire for an antenna, Under 50$ and you're in. And it costs zero but some minimal electric power, you don't even need grid power, run it off your car battery in an emergency. Free as in beer and free as in speech, short range down the block to around the world range- what's not to like? Let them study it some more in places that are using it, I read about in scotland I think they tried it, but don't just dump it out there and "see what happens". I'll wait for my broadband with low powered wifi and a directional antenna or if someone decides to run some better cablez down the road. We don't need to trade one form of electronic human communication for another, we can have BOTH if we are smart.
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 bit ironic that you need a broadband connection to see the video from ARRL - isn't it. I think the ARRL and older hams are just angry about the Internet drawing people from amateur radio and are not getting the picture of how the Internet can be used to encourage more people into the hobby. ie. Repeater relays via the net, IP packet over radio, etc. Hey give up your morse code paddles and step into 2004. (It's also time to ditch the code requirement). Nathan Smith, KC8MTQ nathanmsmith.com
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....
There's still a fair amount of military and civil HF traffic.
A quick scan of the HF bands reveals quite a lot of RTTY and FAX still, as well as VOLMET and the HF civil aviation frequencies (which are still quite active, choose the right frequency and its almost continuously active over the Atlantic). I heard an RAF SSB frequency the other day, it was still active (although the traffic was mostly asking for updates on the football).
Then there's the US Government with its 'Radio Free $(region)' which is still active as well as all those US religious/evangelical stations.
The HF bands are still very active, and may even become moreso again if DRM (Digital Radio Mondial) takes off.
And the powerlines will probably not cause just HF interference. They could also cause interference on other bands, and may even affect medical equipment in hospitals as well as interference to emergency services.
It is a monumentally stupid idea...
(and if you want more broadband, well, BT is looking into running fibre optic cable to every house in the UK...)
>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!