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Wireless Internet by Flicking Lights On and Off

By - Source: Tom's Hardware US | B 35 comments

As long as they don't install the clapper.

Last year we learned about a sort of wireless internet network that operates through the blinking of lights.

Now it's a reality in the city offices of St. Cloud, Minnesota. Local startup company LVX System installed in six city buildings a form of wireless internet that doesn't rely on the 802.11 standards. Instead, it uses flashing lights – sort of like morse code.

Unlike morse code, however, the flashing lights come on and off so quickly that they are imperceptible by the eye. The lights come from LED fixtures overhead, which also double as lighting for the city workers. The light fixtures consume about 36W and provide the same sort of illumination as a 100W fluorescent fixture.

Modems on desktops receive and transmit lights back up towards the lighting fixtires.

Data bandwidth isn't by any means great, as the current technology is only able to deliver about 3Mbps. Wi-Fi is much faster, but the lighting method is more secure and less prone to interference.

Read more from the AP.

Discuss
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  • 0 Hide
    jhansonxi , January 1, 2011 4:05 PM
    Interesting but nothing new. IrLAN has been around for a while and it was proven a long time ago that the LEDs on modems can be used to monitor communications remotely.
  • -1 Hide
    Demonslay335 , January 1, 2011 4:20 PM
    I think this is a brilliant idea, but it may have some adverse effects. For example, even though the lights are flashing faster than the eye can perceive, I wonder if it would still have effects on a person's eye since it is a flashing light still, just like LCD monitors still have effects on people because of this.

    Also, I would still find the security to be bad in terms of reliability. "Heya John, how's it go... oh no, I just covered your modem with a folder and you lost all of that data you were just uploading, too bad!" And you could probably confuse or scramble someone's data by flashing a flash light across the room... I do realize there's an equivalence of all of that with WiFi though, with jammers and all, but it would be much less genius to have a laser pointer on you, lol.
  • -3 Hide
    TheWhiteRose000 , January 1, 2011 4:33 PM
    when I saw saint cloud I was like.
    YES!!!
    Then I saw Minnesota and went.
    Aww!!!
  • 0 Hide
    mavroxur , January 1, 2011 4:52 PM
    Demonslay335I think this is a brilliant idea, but it may have some adverse effects. For example, even though the lights are flashing faster than the eye can perceive, I wonder if it would still have effects on a person's eye since it is a flashing light still, just like LCD monitors still have effects on people because of this.




    The rate at which the LED's change state is MUCH faster than an LCD's refresh rate. For a data rate of 3Mbps you're talking probably closer to a 5MHz switching rate to take into account error correction code and protocol losses. That is much faster than humans can perceive.
  • 0 Hide
    alextheawesome , January 1, 2011 5:01 PM
    TheWhiteRose000when I saw saint cloud I was like.YES!!!Then I saw Minnesota and went.Aww!!!

    I said YES!! to both. Teehee.
  • 1 Hide
    nevertell , January 1, 2011 5:10 PM
    How can you secure such a network ? Does it use WPA ? :D 
  • 4 Hide
    Hellbound , January 1, 2011 5:14 PM
    ""Earlier this year we learned""
    It is Jan 1st you know... :p 
  • 0 Hide
    Marcus Yam , January 1, 2011 6:40 PM
    Hellbound""Earlier this year we learned""It is Jan 1st you know...

    Whoops! (I wrote this one in 2010.)
  • 1 Hide
    iamtheking123 , January 1, 2011 7:31 PM
    To me this seems like a classic engineering waste of time: mild cool-factor but there's already solutions available that are better in every way.
  • 1 Hide
    ProDigit10 , January 1, 2011 8:06 PM
    the bandwidth could get bigger, when using tri or quad color leds.
    Nothing can get inbetween the direct path of transmitter and receiver, without seriously slowing down the transfer, and unless you're physically shielded, its pretty easy to tap off the connection from another laptop,as signals could be received many feet away, perhaps even half a mile away from the source.

    On the laptop/netbook/intelligent phone or whatever receiving device, something like a .25mW led should be sufficient to transmit back to the source, if you're sitting relatively close under the light.

    The good thing is there won't be any harmful radiation floating around.
  • 0 Hide
    bogcotton , January 1, 2011 8:54 PM
    Demonslay335I think this is a brilliant idea, but it may have some adverse effects. For example, even though the lights are flashing faster than the eye can perceive, I wonder if it would still have effects on a person's eye since it is a flashing light still, just like LCD monitors still have effects on people because of this.Also, I would still find the security to be bad in terms of reliability. "Heya John, how's it go... oh no, I just covered your modem with a folder and you lost all of that data you were just uploading, too bad!" And you could probably confuse or scramble someone's data by flashing a flash light across the room... I do realize there's an equivalence of all of that with WiFi though, with jammers and all, but it would be much less genius to have a laser pointer on you, lol.


    Fluorescent lights flicker at about 120 Hz, so if that is the kind of lighting these are replacing, it would be an improvement on that basis.
  • 1 Hide
    harth13 , January 1, 2011 9:36 PM
    i guess the speed of light isn't that fast after all...
  • 0 Hide
    cmartin011 , January 1, 2011 10:01 PM
    We should go with full spectrum light lasers! Like the aliens
  • 0 Hide
    chickenhoagie , January 1, 2011 10:48 PM
    harth13i guess the speed of light isn't that fast after all...

    not the speed that counts. just the bandwidth ;) 
  • 3 Hide
    sandmanwn , January 1, 2011 10:54 PM
    Sounds incredibly expensive, completely wasteful, a maintenance nightmare to have a modem on every desk, and painfully slow.

    Let me guess... It was a government contract.
  • 0 Hide
    lukeiamyourfather , January 1, 2011 11:07 PM
    Anyone who can see the lights could eavesdrop, seems like kind of a bad idea. Not like wireless is that much different I guess.
  • 1 Hide
    razor512 , January 2, 2011 12:00 AM
    Turn that dang flash light off, I was right in the middle of downloading porn.
  • 0 Hide
    Anonymous , January 2, 2011 12:06 AM
    http://www.gadgetzz.com had a similar one
  • 0 Hide
    Anonymous , January 2, 2011 2:15 AM
    "less prone to interference"

    Really? Wouldn't putting anything non-transparent between the modem and the lights defeat the system completely?
  • 0 Hide
    JamesSneed , January 2, 2011 2:22 AM
    You know a wired network would be more secure and faster. A short rang wireless network that doesnt pass through walls and is slow as crap. Im not seeing the light here.
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