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Wireless Internet Access Uses Visible Light, Not Radio Waves
An anonymous reader writes to tell us that a company has demonstrated a new form of wireless communication that uses light instead of radio waves. "Its inventor, St. Cloud resident John Pederson, says visible-light embedded wireless data communication is the next step in the evolution of wireless communications, one that will expand the possibilities in phone and computer use. The connection provides Web access with almost no wiring, better security and with speeds more than eight times faster than cable."
From TFA:
So the cell phones equipped with that would NOT operate with any cell tower that was out of visual range. Doesn't that kind of limit your conversations with your bank to, essentially, being inside the bank building?
No. Because the fiber cable can be punched through walls and such. It does not require line of sight to work. But it works at the speed of light. Which is why it is preferred.
Use Tempest for Eliza and it'll transmit radio at you for real rather than generating a minor html error :P
I read an article about this or similar technology several months ago. Sure, light doesn't do through walls, but that could be an advantage. You could setup a wireless network that asctually stops at the building perimiter.
The other article (not sure if this one does didn't read it) indicated that this technology could be incorporated into LED lighting. Basically your overhead lighting would become the access point. There would be recievers in the room as well that would pick up your transmissions and presumably put them on some sort of physical media (cat6, fibre). Pretty neat, but to me sound extremely finicky.
-- Snow.
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Won't work? so the guys at RONJA are just imagining running 10Mbit/s full duplex over well over a mile using red LEDs and 4" chinese loupe lenses?
And here is GPL'd design: http://ronja.twibright.com/
839*929
For a counter-example, that "real scientists" use, the Advanced Light Source (ALS) produces intense beams of extreme UV or soft X-rays. If you could look at one of those beams, you wouldn't see it, and you would probably not see anything else ever again either. Maybe "burnt to a crisp" *is* an example of human visual system response. Better work on your pedantry some more.
...the future crusty old bastards are already drinking the Kool-Aid.
Well now, that depends on both the wall and the light source. No one has said what wavelength of light is being used, at what power, and what frequency/modulation. While I'm sure his setup goes well beyond IRDA, using LEDs ("light") for data transmissions has been around for over 20 years. Both my cellphone and laptop have IR ports on them -- even used it for internet access once. (laptop doesn't have bluetooth and I don't have the 150$ (f*** you Ericson) USB cable for the phone.)
[Back in college, eons ago, "we" blinded remotes in other rooms through the cinder-block walls with a high output IR LED -- that we made insanely bright to the point of beginning to melt it.]
I didn't RTFA, but if the system were based on diffuse, ambient light in the room, then that shouldn't be a problem.
I swear that I remember a similar idea from around 10 years ago where they wanted to use fluorescent lights in much the same way ... switch them on and off thousands of times per second and you could use them as a data channel if your device had an optical sensor. By setting the hi and low thresholds appropriately, it didn't matter if the sensor had line of sight or not; the reflected light was enough to keep the data flowing.
I think that article came out right about the same time that the security community realized that many network switches/hubs were vulnerable to snooping by observing their LEDs. I guess one man's bug is another man's feature.