Slashdot Mirror
Powerline Networks Finally Viable?
Logic Bomb writes: "MIT's Technology Review has an article discussing the current state of digital networking over electrical lines. It sounds like we may be seeing useable electrical-line LANs soon, but this obviously doesn't solve the 'last mile' problem. I remember once reading something about attempts to provide Internet connectivity over the electrical grid; anyone heard anything recently?" This article may be shocking (in a good way) if you assumed that practical powerline networking was still far in the future, and in a bad way if you thought that companies could easily agree on the right standards and methods to accomplish it;)
Perhaps what happened over the weekend was that the Slashdot server, having achieved sentience, attempted suicide because it was just so embarrased.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
I have done some research into this area for a project at work. The Intellon PowerPacket uses OFDM this modulates the data in the 4.3 MHz to 20.9 MHz band. This is independant of the 60Hz power signal on the line, and at much lower amplitude(voltages). So it means that this will work during the power outages in CA. Also the security is taken care of encypting your info with a 56-bit DES key. This keeps your neighbors from snooping, but not distributed.net or the NSA. Every powerline on the same side of the transformer as you and in transmission range can be connected. It is also independent of the Frequency/Voltage differences in outher countries. Check out HomePlug for the standard wars to come. In essence they have picked the fundamental ideas from Power Packet.
The fight over the best technology is not a bad thing, any more than Linux is a bad thing because Windows already exists. It will drive competition for better technologies, which is a goog thing in such a immature market.
I used to work for a company which makes commercial cable equipment. Most cable companies today that offer broadband use different cable modem technologies, but that is starting to change. Based on all the different technologies in the market, a standard (DOCSIS) was decided upon. Whether modems using that technology are out yet or not, I don't know.
Anyway, incompatible technologies are an importart part of such an immature and unstable industry such as power line broadband.
The "power struggles" among the major companies is a good thing. When a standard comes out, it will be that much better.
-Pete
Soccer Goal Plans
Fight Spammers!
*bzzzzzzzzt* *AAAARGHHH!*
A consortium of about 90 high-profile technology companies will announce Tuesday that the group has finalized a new standard that will serve as a common way for connecting electronic devices to the Net through electrical outlets.
The HomePlug Powerline Alliance, which includes Cisco Systems, Intel, RadioShack, Motorola and Hewlett-Packard, among others, has spent the past year working on a standard for using homes' internal electrical network to link electronic devices. The new standard is based on technology created by little-known company Intellon.
etc....
Okay. So we transmit through the flourescent lights (/. article), which of course doesn't work if you're trying to get some shut-eye or setting up GOOD lighting that bathes your room in light. Now we transmit through the power lines, which doesn't work if you live in California at the wrong time or if you have vacuum cleaners or massive electrovactic flux capacitors or whatever: point is, there's light radiation all over the place, there's power radiation all over the place, hell, there's even radio pollution all over the place (which is why Bluetooth's failing so miserably, as we all know...). But what means of communication do we have that has no parasite devices riding it yet? What magic, wonderful link is there between us and the outside world, over which there is transmited the equivilent of terabytes of raw, reliable data, but which currently isn't at all modulated, although it easily can be made to be, so that rather than what amounts to static today, we get real-live bits?
/that/ today? My roughest calculations show an upper bounds, based on where brownian motion starts to interfere with your data, in excess of 2.82 exobauds of data per household. (The lower bounds, based on the pressure difference that you can modulate not when no water flows through the pipes [and when brownian motion therefore is the only thing screwing you] but rather when everyone turns on every water faucet on full, flushes all their toilets, and opens the fire hydrants outside, /still/ results in good, clean data of about 750kbps, with generous redundancy for error-correction. Either way, lower bounds, upper bounds, that's a good hefty amount of bandwidth).
we need to start sending last-mile data down the water pipes.
Yes, it's true, we have a system that currently can vary in pressure by hundreds of pounds per square inch, that currently has a fairly fixed pressure whose modulations no data-gobbling devices currently utilize, and which services a relatively few number of homes per pipe. Sure, it'll be a shared bandwidth -- or "pipe diameter" -- among all the homes in an area, but then so wasn't broadband cable -- and who's laughing at
Latency? That's estimatable from the speed of sound through water -- since sound is, after all, modulation -- which is "1400 and 1570 m/sec (4593 and 5151 ft/sec). This is roughly 1.5 km/sec (just under 1 mile/sec) or about four times faster than sound travels through air." (Although it "depends on the temperature of the water, its salinity, and the pressure ") Now granted, a second to travel a mile might seem excessive, but bear in mind that, based on the above, the information still travels four times as fast as if you were to yell it. Maybe we can have an asymmetric system, so that you dial in with your modem, and have downloads come through the fat pipe. Okay, enough silliness.
(i'm kidding)
~
While it would be cool to run broadband access over the already existing power lines, that's not what the article was about, nor does anyone suggest that's possible.
Now, maybe that's a whole bunch of bunk, but if it's accurate, what effect would this new device have? It surely would "dirty" up your power a bit, not to mention everyone elses on your phase loop. Enough of these running, and we'd all have to buy whole-house green plugs for everything EXCEPT the outlet we were using for ethernet.
On another note, wouldn't this technology have similar problems as cable modem? If the whole neighborhood signs up, what kind of throughput will you get? I have to believe that running new power cables (to increase bandwidth) is more expensive than burying some extra fiber.
GreyPoopon
--
GreyPoopon
--
Why is it I can write insightful comments but can't come up with a clever signature?
There was a much smaller model built by Norwegian WWII POW's that used the prisoner's teeth (while still in the mouth of course) as part of the radio, but I can not find a link to that. But it really exists in a museum.
-- Another senseless waste of fine bytes.