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Switch On For Powered Data Networks 182

ReLik writes "The BBC has an article regarding power supply via networks. 'Instead of needing adapters, computer networks could soon be supplying the devices they interconnect with both data and power. Some makers of network equipment are already putting the power via data cable system into their products. The basic plugs for computer networks are the same all over the world, raising the possibility that powered data cables could become a universal back-up power supply.'" We've talked a little about specific 802.3 spec advances previously.
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  • by 0x12d3 ( 623370 ) on Wednesday July 09, 2003 @07:39PM (#6404099)
    ... he'll re-define the term "firewall"
    • Not really, all a hacker is likely to be able to do is disrupt the data communications on the line, they probably wouldn't even be able to detect whether the line is carring power. Think xDSL over a phone line: hackers may be able to totally disrupt the xDSL connection, but they can't stop people making calls on the phone line.
    • How is that going to work out with California's Rolling Black-Out?

      One block is going to be shut down and all their neighboors will provide power through the LAN...

      Another bad thing for tge PG&E...
  • ddos (Score:3, Funny)

    by Gandalfar ( 599790 ) on Wednesday July 09, 2003 @07:40PM (#6404106)
    This just calls for ddos attacks on LAN ;-)

    There better be some good power overcharge protection included ^_^
  • hmmmm... (Score:4, Funny)

    by tony1c ( 610261 ) on Wednesday July 09, 2003 @07:40PM (#6404109) Journal
    I wonder if they'll be sending it as straight binary or xml.
  • new? (Score:2, Insightful)

    by Anonymous Coward
    Firewire? USB?
    • Re:new? (Score:2, Insightful)

      by RALE007 ( 445837 )
      Don't forget power to your keyboard or mouse via DIN and Mini-DIN (ps/2) connectors, which predates Firewire and USB.

      Power through a communications (I/O) connection is nothing new, but power on a standard so widely used has never been seen. Also, firewire, USB, and my own DIN examples have provided power only to peripherals. This new system appears to offer power to a standalone device. In essence this is a new international electrical standardization. Since it is built ontop of existing compatible eth

      • Re:new? (Score:2, Funny)

        by HTH NE1 ( 675604 )
        In essence this is a new international electrical standardization. Since it is built on top of existing compatible ethernet standards, the US, Europe, and Asia are placed under the umbrella of one universal compatible power standard. ...[T]he possibilities are very exciting in my opinion.

        Don't worry; I'm sure they'll come up with a way to mess it up.

        After all, what good is a new power standard if it doesn't create a new adapter that the consumer is required to purchase? Gotta have more gougeables on th
        • Don't expect them to stop at a new adapter. For years we've been paying for 8 copper wires (in Cat5)and an 8 conductor plug and socket when we only needed 4. Do you really think they're going to let us finally put those other 4 wires to use instead of having to buy more wire? I'm expecting a new, not quite compatible with RJ45 jacks, plug that uses a special cable with 22 or 24 gauge wire (2 pair) for data and 20 or 18 gauge wires for the power (bigger wire, less wattage wasted heating it). This cable,
  • by loucura! ( 247834 ) on Wednesday July 09, 2003 @07:41PM (#6404117)
    Both HIGH SPEED/POWER, AND FULL SPEED/POWER... and the as-yet-unreleased LUDICROUS SPEED/POWER.

    This is just another case of the Brits trying to steal our momentum... those bastards.
  • by hashish ( 62254 ) on Wednesday July 09, 2003 @07:42PM (#6404123)
    states that if you rub two sticks together you get fire.

    Seriously, how long have did it take people to release there is a current in their ethernet cable? I known of products (home made and retail) that have been around for years that utilise this power supply.
    • No, power over ethernet is relatively new. By saying "utilise" you make it sound like every ethernet device puts out usable power, which isn't true. I think you're thinking of phone cables, which have had power running through them for many many years, to power phones that don't have another power source.
  • Really? (Score:5, Insightful)

    by geekmetal ( 682313 ) <vkeerthy AT gmail DOT com> on Wednesday July 09, 2003 @07:42PM (#6404126) Journal
    The days of travelling with lots of different adapters to ensure you can recharge your laptop, phone and other gadgets could soon be at an end.

    How effective would this in a world striving to move to wireless protocols?!
    It wouldn't get the chance to make a scratch let alone a mark.

    • Re:Really? (Score:3, Insightful)

      by El Kevbo ( 81125 )
      How effective would this in a world striving to move to wireless protocols?!

      Wireless is exactly where this technology is making the biggest impact. No one is thinking of charging laptops but powering wireless access points. We have to run Cat5 to our access points anyway - why not run power through that same cable?

      Kevin

    • How effective would this in a world striving to move to wireless protocols?!

      Sigh. Where is Nikola Tesla now that we need him?

  • by NeoSkandranon ( 515696 ) on Wednesday July 09, 2003 @07:43PM (#6404129)
    I admit I don't quite know the exact ins and outs of this technology, but a few things do come to mind:

    Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?

    Also, would this work in situations using coax cable, where there is no other pair?

    Lastly, can you put 120VAC along wires that thin without causing lots of power loss and making a lovely fire hazard?
    • This is how Cisco VoIP works. You can get Power Over Ethernet blades for your Catalyst 6509 which will provide the power for your VoIP phone as well as the data. Works like a champ... or so they tell me... those sales people :)

      • Actualy it works VERY well for there voIP phones and a few other devices like intel AP's and mini managed switches. It' DC and nut much current enough the run a laptop and probably not enough for a full desktop replacement. Last I check it supplied 18 watts.
      • We also do this with our 802.11b ap's that run multiple floors up. There is a signficantly better signal pickup at the roof then our lower floor.

        It allows us to not worry about wiring as well as providing remote reboots if the unit hard locks. Though we have never had to use the latter anytime.
    • by Anonymous Coward on Wednesday July 09, 2003 @07:49PM (#6404162)
      Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?

      Not if done properly.

      Also, would this work in situations using coax cable, where there is no other pair?

      Yes.

      Lastly, can you put 120VAC along wires that thin without causing lots of power loss and making a lovely fire hazard?

      You can't, but the problem is worse. Your notebook doesn't run on 120VAC. It runs on DC power that is much lower voltage. The power supply steps down the voltage before the power gets to your system.

      The problem is that when you lower the voltage, you raise the current, and current increases heat as it gets higher. So, low voltage, high current power transmitted over CAT5 would be a big problem.
    • Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?

      USB supplies power to USB peripherals, as well as Data, so I don't think it would be a significant problem.
    • This is a little DC power for IP Phones and WAPs not 120VAC for your computer.

      48V at 350mA max DC.
    • by wfberg ( 24378 ) on Wednesday July 09, 2003 @08:06PM (#6404264)

      Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?


      Gee, I suppose those boys at the IEEE haven't paid any attention to that. How embarrassing. Those electrical engineers, always chasing the girls, playing in rock-bands, and entering in surfing contests! This kinda thing was bound to happen...
    • by SuperBanana ( 662181 ) on Wednesday July 09, 2003 @08:12PM (#6404292)

      Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?

      If it's DC only and well filtered/buffered, no. If it's RF, or DC that's not well filtered(noise is generated from any kind of switching, even in low power ICs). Buffering it isn't that tough- you can sorta think of it like a bucket under a faucet. As long as your average water needs over time don't exceed the flow out the faucet, you can take whatever you want, even large amounts suddenly, without causing pressure changes in the rest of the house. Now, imagine drawing a cup of water every once in a while from a faucet directly and shutting the water off really hard- helloooo water hammer!(similar things happen when you switch on/off power down a long line, or to/from an inductive component.)

      Also, would this work in situations using coax cable, where there is no other pair?

      Actually, Dallas Semiconductor(now part of Maxim) came up with what they call the One Wire protocol; it only needs one line for power+data(hence the name, even though you still need some sort of ground.) It's a pretty well set up system, works nicely- plenty of info on the web and their site, and there's even guides on designing a proper network- and shows the effects of cable length on things like pulse smoothing, noise, etc caused by communications and device power draw. It's VERY thorough.

      Lastly, can you put 120VAC along wires that thin without causing lots of power loss and making a lovely fire hazard?

      Actually, power loss is less with higher voltages- that's why high tension wires are tens of thousands of volts. P = I * V; 100W at 120V is .83 amps, but at 12v, it's 8.3A.

      This is important, because the higher the current, the higher the voltage drop; V = I * R. All wire(except superconducting) has some resistance, and the lower the current, the lower the voltage drop end-to-end, and the lower the amount of power(heat) the wire absorbs. Wire(or perhaps more accurately, cable) is rated in terms of maximum voltage mostly from the insulation type(its dielectric strength) and current- its gauge, or thickness of the solid or stranded bundle(larger #'s = smaller thickness).

      This is one reason automotive manufacturers want to go to 48V systems; the wiring between the battery and main bus/alternator can be much thinner, for example. Take a look at your battery cables some time- they're VERY heavy gauge. Also, as previously mentioned, stuff like dirt on contacts and corrosion between clamps+terminals or in splices are much less bothersome at lower currents.

      • "Also, would this work in situations using coax cable, where there is no other pair?

        Actually, Dallas Semiconductor(now part of Maxim) came up with what they call the One Wire protocol..."

        Does it differ significantly from other (generations old) phantom power implementations other than the signal being digital rather than analog? Have they figured out how to avoid having to use blocking capacitors?

    • I was wondering the same thing. The general rule is that 1 meter of cat5 and AC cable laying next to each other, will cancel out the cat5 signal completley (I've never tried it honestly, but that's what I was taught).

      Of course you could transmit DC, but you have to double the power every 50 feet over copper IIRC?

      • I have enough 120V lines and Cat5 around to say "bull" to this. I run Cat5 through the rat's maze behind my stereo. The speaker wires, power wires, RCA cables, other wires, etc. do not seem to interfere with each other.

        What does seem to cause problems, strangely enough, is my USB Logitech mouse. Put it's wire near the low level RCA cables and get a loud ass buzz. Thus my stereo connection to the computer is in back, and the mouse is on the front USB port.
    • Power doesn't cause interference. You get constructive/destructive interference when there are multiple signals with the same frequency.

      Some CableTV companies run video channels (52MHz to say 750MHz) and power (90V 60Hz AC) down the same coax. They use a diplexer (frequency splitter) to separate the AC from the video. Unless there is noise in the video bandwidth present with the AC, there shouldn't be any interference contributed by the AC.

      The big difference with Cable TV is that the coax they us

  • Power over ethernet? (Score:5, Informative)

    by pv2b ( 231846 ) on Wednesday July 09, 2003 @07:43PM (#6404130)
    Yes, power over ethernet (POE) has been possible and been for quite some time, although mostly for powering up wireless base stations...


    Here is some info by POE from NYCWireless [nycwireless.net]...


    Now just give me wireless repeater base stations powered by tesla coils and I'll be in heaven. :-)

  • by dfn5 ( 524972 ) on Wednesday July 09, 2003 @07:44PM (#6404133) Journal
    Yup, you'll now have to get a licensed electrician to punch down that patch panel, unless you don't mind fried IT people piling up at the bottom of your 19" rack.
  • by Anonymous Coward
    ...is now as simple as feeling how warm the ethernet cable is.
  • by Trogre ( 513942 ) on Wednesday July 09, 2003 @07:46PM (#6404145) Homepage
    Golden rule of data cable laying:
    Avoid power cables! If you've gotta go near the buggers, cross 'em at right angles.

  • GSM Base Stations (Score:4, Interesting)

    by Mike McTernan ( 260224 ) on Wednesday July 09, 2003 @07:48PM (#6404155) Homepage

    These [ipaccess.com] guys make a GSM/GPRS base station that is powered over Ethernet.

    Cool huh?

  • What's the delivery mechanism for this? Is it like Cisco's unused pairs method for their in-line powered phones? Kinda rules out using it in conjunction with Gig-E in that case.
    Also, the available power will be pretty minimal. IIRC it's a max of 65W, and the gauge of Cat5/6 cable isn't up to high current applications.

    Oh and I can't see this working with Base-FX either, funnily enough.

  • by Eric(b0mb)Dennis ( 629047 ) * on Wednesday July 09, 2003 @07:50PM (#6404175)
    So.. we have power over data lines and data over power lines..

    What a world, I'm so glad to be alive in 2003 :)
  • Anyone know how much current the new spec allows? (yes, I did rtfa and it's not in there) I don't think Cat-5 (or similar) cable could carry much current, but I could be wrong. Since it can power a razor, I assume it would be enough to power basic ethernet devices, but I'd still like to know the exact specs.
  • by GillBates0 ( 664202 ) on Wednesday July 09, 2003 @07:55PM (#6404210) Homepage Journal
    Time to pull out RFC 3251 RFC 3251 [faqs.org]!!!

  • by LoRdTAW ( 99712 )
    This does not look like it will be used for anything larger then small hand helds and other similary sized devices. Cat 5 is normally 24 AWG which has very high resistance per foot making long runs useless. at around 50ft you might have about 4 or 5 ohms. Unless you have 2 or 4 pair cat 5 with a pair of 18awg or larger in the same jacket it doesent have much use for anything drawing more than 10 watts or less. although making such a cable wouldent be such a bad idea.

    Would be cool to have some type of hybr
  • by jCaT ( 1320 ) on Wednesday July 09, 2003 @07:56PM (#6404216)
    Ok, so maybe this wasn't exactly what they were talking about. It's still kind of fun though...

    The Etherkiller [fiftythree.org]

  • FireWire, USB (Score:5, Interesting)

    by 73939133 ( 676561 ) on Wednesday July 09, 2003 @08:02PM (#6404244)
    "The RJ45 connector is a universal outlet," he said. "It's the only one identical in Asia, Europe and the US."

    The same is true for FireWire and USB, and those are far more widely available. In fact, USB is increasingly becoming the standard for recharging portable devices, with USB power cables for most PDAs and cell phones available. FireWire might be better for this than USB because it can deliver more power, but maybe the USB standard will catch up.

    You can even get a USB toothbrush [gizmodo.net].

    The RJ-45 connectors used with Ethernet really don't do it for me; I think both USB and FireWire connectors are far better designed. I think POE (Power over Ethernet) will remain a niche market.
    • "The RJ45 connector is a universal outlet," he said. "It's the only one identical in Asia, Europe and the US."

      Oh great,

      "So we want to make sure that some of them are different..."

      I love the possibility of different countries opting for different voltages. That way you can chance frying your laptop every time you travel.

      Xix.

    • USB is far more available than Ethernet? Riiighht.
    • What RJ45 connectors have over USB and Firewire connectors is that they don't pull out when the cable get's tugged.
  • It doesn't interfere (Score:5, Informative)

    by Rufus211 ( 221883 ) <rufus-slashdot&hackish,org> on Wednesday July 09, 2003 @08:04PM (#6404258) Homepage
    There have been quite a few posts so far about how running power over data lines is a bad idea and would cause all sorts of bad EMI, killing the data signal. But it actually doesn't. The power going through these is low-voltage DC (I think 12v), *not* high-voltage AC like wall power. AC produces changing magnetic fields which cause EMI, while DC produces a static magnetic field, so the data could care less. This is the same way that USB works (at 5v) and even POTS (plain old telephone systems...those have a full 48V DC...not always very nice when you forget that fact doing wiring). I haven't actually played with any of the equiptment myself, but from what I've read everything is low-voltage and low-power enough not to cause any sorts of problems at all.
    • Two critical facts...

      1) Twisted Pair style ethernet (10Base-T and up, not thin or thick) uses a differential reciever to cancel noise. As long as the same noise is present on both conductors of the pair, everything is, as EEs say, "Hunky Dory".

      2) POTS lines run 48V - 96V on ring - without electrocuiting people.

  • Ground loops? (Score:3, Interesting)

    by Anonymous Coward on Wednesday July 09, 2003 @08:05PM (#6404261)
    Now this could be interesting. I worked on a system that toasted three Ethernet cards before we got a clue and stuck an isolating piece in the middle. It was on a long loop of thinnet cable which connected several buildings at a high school.

    I suspect many of the buildings had separate power feeds and therefore different grounds due to being built gradually over the course of 40 years or so. The potential eventually got us, and cost us a few bucks and a lot of lost hair.

    They had better be very careful with this stuff. Interconnecting building grounds over your network cables is a good way to fry equipment and unsuspecting people.
    • Re:Ground loops? (Score:3, Informative)

      by azimir ( 316998 )
      That's why you run fibre between buildings. A copper->fibre 10 or 100 bridge is quite cheap these days. The fibre is also not so expensive anymore.

      Light has no ground.
  • 802.1u (Score:5, Informative)

    by Jah-Wren Ryel ( 80510 ) on Wednesday July 09, 2003 @08:07PM (#6404266)
    Check out the prelimary specs for 802.1u - power over wireless ethernet. They are planning on using microwaves to send the data and power to wireless devices around the home and office.
  • You know, this is a cool idea, but the true killer app is when they bring this technology to 802.11.

    Oh wait...

  • Doesn't it seem practical that separating data from power is an essential property for data security? Ever seen The Recruit:
    http://us.imdb.com/Title?0292506

    Sounds like Ice9 to me.
  • by MerryGoByeBye ( 447358 ) on Wednesday July 09, 2003 @08:19PM (#6404321) Journal
    Umm, hello...

    Can anyone please tell me what the point of putting real juice down Ethernet would be? Isn't Ethernet like 30 years old? Why don't we come up with a new FireWire/USB type plug with a configurable interface, set it up with +5V, +12V, Ground, Data Send and Data Check, set up generic, open hardware-level frames capable of wrapping all other protocols and a spankin' new cable/plug combo which would shield the voltage lines? I mean, Christ, let's move on. Why are people still talking about Ethernet? Oh, and a better endplug would be nice; one that releases with a sharp jerk, stays put with a slow tug and has a satisfying, soft "click" when engaged.

    I realize I will get downmodded for this, but I am being quite serious.
  • by Jeremi ( 14640 )
    Yeah, big deal... let me know when they develop power-over-WiFi.
  • MacWireless.com sells a cable setup [macwireless.com] to allow you to do this now with your base station.

    At $30 a port it is a LOT cheaper than going with a Cisco POE solution for base stations.

  • with swiches, 802.11 APs and with IP phones.

    See http://www.cisco.com/en/US/products/hw/switches/ps 663/products_data_sheet09186a00800924d0.html & http://www.cisco.com/en/US/products/hw/wireless/ps 4570/prod_quick_installation_guide09186a00800a3fe1 .html for examples.
  • FIREWIRE

    Been there, done that. GREAT IDEA though...

    With that said -- yes, I know that my 10Mbit Internet running at 5Ghz is back feeding the antenna power. Yeah, it's nice to see 900K/sec @ home -- and it's slowly taking over our branch offices as well.

    I had one office that wanted a whole bunch of Snap! servers (cute, but I personally don't find their file system to be enough). Instead of trying to having umteen million power adaptors plugged in I rigged power originating @ the switch to feed the servers
  • "The humble RJ45 could have a big future" That would be an appropriate statement for the late '80s, yes. (unsure of the exact date of RJ45 standard )
  • The very first time someone plugs power over ethernet into a non-power over ethernet hub or switch.

    -ted
    • Someone in Europe's evidently has already done this. This picture [alledegode...optaget.dk] shows a 230V mains-to-RJ45 adapter cord, all nice moulded-on plugs and all.

      Makes the RS232-mains adapter set I made once when needing a long serial line and having an extension cord available look rather primitive.

  • ...raising the possibility that powered data cables could become a universal back-up power supply

    Great! So, now, when my power goes out, my computer can instead draw power from the network cable. That cable will in turn receive its power from the hub, which is plugged into... umm... the wall... with no power. Hmmm...

    No, no, the hub will get its power from the network cable from my DSL router! And the DSL router will get power from the phoneline providing the DSL. Hmmm... no, wait, not enough powe


  • Does this mean I could harvest all my spam and use it to power my house?!? ;)

  • A lot of USB devices pull their power through the cable...this isn't revolutionary.
  • a wireless protocol so I can tap on my neighboor's electric network :)
  • I'll finally get rid of this mass of cables resembling a 'Borg cube's innards behind my desk running to my KVMs. I'll replace them all with a mass of CAT5 that will look much nicer won't it?

    Well, at least it will be about half the number of cables to keep track of.
  • The network supplying the power for the computer? Kind of like the telephone network supplying the power for the telephone. This reminds me of a story: Actual dialogue of a former WordPerfect Customer Support employee:

    "Ridge Hall computer assistant; may I help you?"

    "Yes, well, I'm having trouble with WordPerfect."
    "What sort of trouble?"
    "Well, I was just typing along, and all of a sudden the words went away."
    "Went away?"
    "They disappeared."
    "Hmm. So what does your screen look like now

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