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Broadband over Powerlines
scubacuda writes "Today's Bottom Line links to an article on Internet-over-powerline technology. St. Louis-based Ameren Corp and other utilities are testing are testing the technology, and, according to the article, "many consider it increasingly viable." Proponents claim the powergrid technology will bolster broadband competition, lower consumer prices and bridge the digital divide in rural areas. Skeptics say that few tests prove its financial and technical viability. Kludge, panacea, or hoax? (I'd think it was a total crock had I not personally known someone working in India with a PCL company)"
Didn't we have problems with this when it was trialed a few years back i nthe UK? i'm sure I heard reports of lamposts going haywire, any URL's?
The only problem I see is that every overhead power line is going to turn into a giant antenna picking up interference. My school got squeemish enough about a teacher with too long of an ethernet cable, what about miles and miles of power lines out in the open during an electrical storm?
It'll "bridge the digital divide" and give you "unlimited broadband"... ...For a while, until it catches and becomes popular and runs all the alternatives out of business. Then they'll impose bandwidth caps, PPPoE, and start blocking ports. Then they'll say "sorry, can't access your work VPN from our system...unless you upgrade to a hideously priced business rate."
They've been promising this for years. It seems that it would make sense to run all the utilities/services in one set of cables anyway. Hopefully this will reduce the cost of the "last mile" problems.
Then again, with just a handful of providers in each area, I'm sure they will collude to support prices. You'll be able to get pretty cheap, mostly one way connectivity bursting with ads and spam, and pay a hefty price for a simple two way connection.
Wow, CmdrTaco actually submitted a story! How's the wife doing ya, Taco?
Karma: Bad (mostly affected by being such an asshole)
Now when a network component fails I can worry about getting medium voltage power directly into my motherboard.
Didn't we learn a long time ago to separate power and signal wires?
BTW, here's another version of the story.Have you seen my stapler?
In Israel the (single) power company used this technology for years for its own data communication.
I think the reason it never moved to other sectors involved both the high price of the required modems and the requirement for a licence (being a communication provider requires a licence, at least here in Israel) which was always a problem to gain here.
About a year ago German company RWE (big energy corporation) was cheered as the new leader in broadband connections via powerlines. It even was available to customers, but eventually they quit the powerline business in September 2002. Appearantly they had only 200 paying customers instead of the expected 120000.
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The trouble with broadband over power lines is that power systems were not intended for data transmission. While the cables may work ok everything else is quite likely to cause problems: the splices from repairs, the shunts, the transformers. I doubt that adequate records were kept just in case the power system was going to be used for broadband in the future, so repeated trips by techs might be necessary, just to get it to work.
It would probably be cheaper to just run fiber along the distribution lines, which is what some power companies have done.
Look at what happened when the telephone companies went to DSL, in some places they had to redo 20 years of repairs that were adequate for phone lines, but not for high speed data. It cost a them a fortune and it is almost a certainty that the power companies would be faced with the same situation if not worse.
Heck, you could put this together in 5 minutes. http://www.knology.net/~bburdette/ethernet-over-ac .jpg
Try it on your work network!
In the states of ND, SD, MT and MN there are thousands of miles of fiber optic cable laid for telecom. IN ND alone there are 14 local telephone companies who have joined to set up 9000 miles of dual 2.5G Sonnet loops and nearly any resident in the state can get a 512k/512k DSL line if he wants it. Most do not have it for what I believe is the following reason. Most people understand that every house has a phone connection and expect it. But if the telcos set up every home with the combo phone and DSL port, as a standard setup, people would become aware, and buy the service, subsequently lowering the price from $100 down to something reasonable. All the connectivity is already there. Just the last visible connections in the house are missing. There really is no digital divide in a physical or electrical sense. Just awareness of need and comfortable price point.
In the energy services field it is common to send data up the drilling fluid on a drilling rig. They use a valve downhole to modulate pressure waves up the pressurized fluid in the pipe. This gives them details of the environment at the drilling bit. They data rate is quite low.
That's not news to me. I recall having read about similar experiments here in Italy about 7 years ago.
Why does it take so long for this technology to become widespread? Perhaps the big telcos don't like it.
They had this when I lived in Germany. The deal isn't that they sent a signal over the HV wires. The HV wires come into the local tranformer and get stepped down to the right voltage and smoothed out. At that point you can have a bypass to filter out the higher frequency signal that carries your packets. So from the house to the transformer you can have one set of signals riding on a normal 220 V 50 Hz (+/-) power. At the bypass, you can change the frequency so it can travel over the high voltage lines or can send it over to fiber from the tranformer to a central location. The difference between Germany and the States is that in Germany, they have a transformer that services an entire neighborhood. So you can put in the equimpent at the transformer and have potentially thousands of customers to regain the costs. In the States, there may be a neighborhood transformer, but there are also generally transformers every few houses for the final conditioning. That means expensive equipment that needs to be recouped over a small number of people.
That's nice in theory, but totally inpractical. Basically, you'd have to sync both ends of the data transmission with frequency, except that the grid frequency is not a constant, and unpredictable...
The 60Hz frequency standard in the US is a "desired" point... everything, from turning on a blender at home, to firing up your local steam generator for the morning ramp, has an effect on the grid, from a minute twitch to a big swing. If there is more demand than generation, the frequency slows down as energy is sucked out of the grid; likewise, overproduction of electricity causes the frequency to speed up. Now, it takes many many MWatts to make a change, because so many loads & generators are wired in parallel, but it's still possible.
There are many companies operating in parallel across the USA (abbreviated RTOs & ISOs) that work to balance the supply & demand of electricity every second... we track the frequency (graph here) in an attempt to balance the whole thing out, by calling on more generation when the frequency is low, and telling the to back off when it is high...
Now, as far as sending data by modulating the AC wave, the problem here is the "scrubbing" effects of Transformers. The premise behind high voltage transfer of electricity is to use transformers to step up the voltage & lowering the current. Lower current equates to less heat loss, so you can send the energy more miles for the same loss. Now, the problem is the magnetic core does not have a good frequency response when converting E to M to E again... they're designed for a low frequency after all. So, you end up with every transformer removing all of the high-freq. oscillations.
I remember there being an articl in "Popular Science" over this subject in an October of 1999 or 2000 issue. I can't find it now when I search the archives at Popular Science. It described a company in Dallas Texas that was patenting the technology to get the signal through a transformer station. They explained that the issue with the IP over powergrid worked by piggy-backing the packets over the EMF radiation that is generated around high voltage lines. The problem was not in how to piggy back the signal, rather how to extract it from a transformer station where the EMF fields of multiple cables merge. The solution this company came up with was to convert the data into a microwave signal at one end of the transformer station and beam it to the other end of the transformer station. I presume they would do something similar around the transformers at the neighborhoods as well. They were creating a prototype device that made use of maser technologies (basically a laser that operates in the microwave band of EM radiation). They were also patenting their devices that extract the signal from a wall plug (~110 US) and convert it to either 10BaseT or other options. The last time I checked up on the company they were beta-testing the technology in North Texas and Oklahoma. I'm not sure where they are now, as I don't remember the name of the company.
Aside from the technical hurdles of placing data on the powergrid, I think there would exist a technical hurdle in regards to data security. The EM fields given off by powerlines can affect your AM radio (and FM sometimes), so we know the signal is strong enough to affect electronics components. Since it is that strong, we can assume that the signal could be "read" by electronics components as well. Particularly, those who wish to construct "scanners". Anyone within close proximity of the powergrid could "tap" the line for data extraction. A significant security effort would need to be undertaken by ISP's to provide encrypted transmission of data. Currently, packets are simply sent down the wire with no encryption (unless you encrypt the data yourself). The wire itself provides a physical barrier to a data thief in that you must physically connect to the wire. With the powergrid you merely need to be in the proximity of the wire. I think this would only apply to overhead powerlines and transformer stations.
Additionally, data could be corrupted by natural causes such as solar flares and thunderstorms. Both of which would zap your data by scrambling the magnetic fields that you are depending on. Again, this might only affect the overhead lines and the transformer stations. Of course, if the transformer station went out, the whole issue becomes moot.
To know is to have knowledge....to understand is to be enlightened.
In a small town in Germany 'powerline' works for me for longer than a year now. Download rates are not miraculous but it is possible to download 700MB iso-images with a stable rate of 70k-bytes /second. :-)
A problem I had was that not all power sockets can be used. Most sockets seem to pickup too much noise or there is no signal at all.
Nevertheless I like it