News WiFi competitor uses visible light

[CardJoe]

http://www.bit-tech.net/news/2008/10...isible-light/1

A wireless networking system designed around LED-based visible light is being developed at the Boston University College of Engineering

[liratheal]

Wouldn't LED fans and the like interfere with these?

[Goty]

ANY kind of light in the range these LEDs are supposed to operate in will interfere with this system, but I've found an even bigger issue: what if I want to game online with the lights off or surf the internet at night?

Seriously, why do we pay these people? I want to get paid to come up with impractical solutions to problems that don't exist!

[DougEdey]

They should use IR LEDs or something, but this'll be dead easy to block. Bit o' paint...

[Krikkit]

I suspect that it'll be designed for office work - somewhere where the lights are on all the time.

The problem with using visible (or even near-visible) light is that it's very easy to interfere with.

I can see what they're trying for with this one, but I'm a sceptic until further notice tbh.

[Blademrk]

Only problem I see is that LED lights do not give out enough light. I've tried replacing the halogen bulbs in my bedroom with a set of LED bulbs (they use the same fittings as the halogen bullbs) and they're just not bright enough. I've ended up swithching 1 of the 3 bulbs back to halogen (the one aimed at the computer incidently).

[Stuey]

Originally Posted by liratheal

Wouldn't LED fans and the like interfere with these?

No, but I don't want to offer an explanation that could be wrong.

At the very least, consider that such a system would depend on line of site. There would need to be a sensor oriented up or otherwise towards the light fixture transceiver. Unless you have uber-bright case lighting that is itself an immensely powerful light source, in proxiimity to or aimed at the sensor, everything should be fine.

Consider television remotes. These work via IR. Many lamps emit IR light as well. Does having a light on in a room prevent you from using an IR remote control with the television? Granted IR remote signals are modulated, but the TV sensor won't/shouldn't pick up non-modulated IR signals even of the same frequency.

Another thing is that LEDs typically emit at very specific wavelengths, and non-traditional colors emit at very specific color combinations. Maybe that "feature" can help in some way.

[liratheal]

Originally Posted by Stuey

No, but I don't want to offer an explanation that could be wrong.

At the very least, consider that such a system would depend on line of site. There would need to be a sensor oriented up or otherwise towards the light fixture transceiver. Unless you have uber-bright case lighting that is itself an immensely powerful light source, aimed at the sensor, everything should be fine.

Consider television remotes. These work via IR. Many lamps emit IR light as well. Does having a light on in a room prevent you from using an IR remote control with the television? Granted IR remote signals are modulated, but the TV sensor won't/shouldn't pick up non-modulated IR signals even of the same frequency.

There are many ways to prevent interference with such a system - that's the least of their engineering concerns.

Another thing is that LEDs typically emit at very specific wavelengths, and non-traditional colors emit at very specific color specifications. It could be that they could be tailored to emit an exact frequency that can be detected with less chance of interference or being washed out.

Ah, fair enough. I was asking out of curiosity, since I know jack about light and what has an effect on it.

That said, I did used to have my PC on my desk, back in the day when it was bright enough to blind the nearest person to it >.>

[airchie]

This sounds pretty cool but would this not be susceptible to a variant of Van Eck Phreaking?

[liratheal]

Originally Posted by airchie

This sounds pretty cool but would this not be susceptible to a variant of Van Eck Phreaking?

That is the most insane thing I have ever seen. Evesdropping on monitors?!

Time to make my monitor a tinfoil hat

[proxess]

What if the kiddies wanna watch pr0n and not let their mums know they're up?

[Delphium]

Think they should come with.. warning may produce fits or headaches due to constantly flickering light

[Krikkit]

At 10Mbps, you won't even get close to seeing it.

Originally Posted by Stuey

*snip*

TV remotes don't transfer masses of data though, they transmit a small amount of data loads and loads of times, and even then they can be a bit fussy.

As for specific wavelengths, yes, LED's emit a very small band of frequencies, but you will still get interference from other light sources, especially white lights.

[p3n]

Epileptic (sp?) office workers are a thing of the past!

[Xir]

Originally Posted by DougEdey

They should use IR LEDs or something...

Been there, it's called IRDA and used to be standard in mobile phones, laptops etc. ;-)

[DougEdey]

True, but surely we've advanced the IR spectrum refinement now and can increase the data throughput, my phone doesn't have IRDA on it.

[dyzophoria]

just improve on current radio signals, rather than go back to line of sight communications like these (even if you say you have lots of led to eliminate line of sight problems), I still find this so called new technology a bit of a let down

[Goty]

Radio is still line of sight until you get into about 6-meter and greater bands.

[UrbanMarine]

Look towards Japan their WiFi networks are crazy.

[HourBeforeDawn]

well the nice thing is you could have the wifi where you want it, so like in a room with four walls you dont have to worry about the signal going outside so you could leave it unsecure for guest and not worry about people out side leaching off of it, so ya I can see the applications in this, or like say in Hospitals where such signals interfere with equipment, maybe using the light spectrum wont have the same effect so they would be able to use more wifi based devices.?