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Author Topic:   Transmission of data by LED light
New Cat's Eye
Inactive Member


Message 16 of 32 (630981)
08-29-2011 5:40 PM


I don't get it
I haven't watched the video cause its too long to watch at work...
But how would my lightbulbs receive the information?

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 17 of 32 (630985)
08-29-2011 5:49 PM
Reply to: Message 15 by RAZD
08-29-2011 5:33 PM


Again the light limits the broadcast to improve security issues.
Is security an issue? Economically I would say that this wouldn't be a good selling point. There are many things you can do to achieve secure comms other ways that don't rely on new tech. If you were looking for secure data transfer then lasers would be where I would look. I think DARPA has already been down this road with using lasers for comms with subs.
It is a novel idea, nothing more. One I am sure others have thought of...but I am not up to a patent search.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 18 of 32 (630987)
08-29-2011 6:18 PM
Reply to: Message 14 by jar
08-29-2011 5:32 PM


Communication is limited to the speed of the slowest link and light is line of sight and subject to medium degradation.
It will be more limited by the transmission system prior to it being turned into light. It is a moot point with power lines being the main route of data transfer, you can't exceed their usable bandwidth.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 19 of 32 (630988)
08-29-2011 6:19 PM
Reply to: Message 18 by fearandloathing
08-29-2011 6:18 PM


That is what I said. It is the part before becoming light that will be the limiting factor.
And the power grid in the US is not all that up to date.

Anyone so limited that they can only spell a word one way is severely handicapped!

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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 20 of 32 (631021)
08-29-2011 10:16 PM
Reply to: Message 7 by RAZD
08-28-2011 11:29 PM


Still needs to get from A to B and then back to A for the information to be useful/used.
Not necessarily. Unidirectional digital networks still have some uses; for instance, car radios can get station/artist/song information now. That's a kind of unidirectional network that we know better as a "broadcast."
LED networks could have use as a kind of near-field broadcast system, particularly since it's fairly easy to tune out unwanted transmissions by blocking line of sight or filtering colors.
There's a lot of different kinds of networks besides the packet-switching type that everybody is thinking of.

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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 21 of 32 (631022)
08-29-2011 10:17 PM
Reply to: Message 16 by New Cat's Eye
08-29-2011 5:40 PM


Re: I don't get it
But how would my lightbulbs receive the information?
Who says it has to?

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 22 of 32 (631096)
08-30-2011 10:55 AM
Reply to: Message 20 by crashfrog
08-29-2011 10:16 PM


Here is a little more on the subject. Seems there is a lot more interest in this technology than I thought, many or them would have to do with not wanting RF in certain places, planes, operating rooms...
quote:
LED light fixtures transmit digital data at 800 Mbit/s
Berlin, Germany--By simply modulating the LEDs in an LED lighting fixture, it can become a digital transmitter for an optical wireless local-area network (WLAN). Researchers at Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute (HHI), Siemens, and France Telecom Orange Labs are working to make this concept practical, which would allow simultaneous transmission of multiple video to photodiode-equipped computers and mobile phones.
By the end of May this year, the scientists were able to demonstrate the transfer ot data at a rate of 100 Mbit/s without losses, using ceiling LEDs in the ceiling that illuminate ten square meters or more. The receiver can be placed anywhere within this area. This means that we transferred four videos in HD quality to four different laptops at the same time, says Anagnostis Paraskevopoulos from the HHI.
The scientists are working on higher bit rates. Using red-blue-green-white light LEDs, we were able to transmit 800 Mbit/s in the lab, said Klaus-Dieter Langer. That is a world record for the visible-light-communication (VLC) method. The HHI scientists will showcase how videos are transmitted by light in Hall 11.1, Booth 8 at the International Telecommunications Fair IFA (Internationale Funkausstellung IFA) in Berlin from September 2-7, 2011.
Use include VLAN in hospitals, for example, where radio transmissions are not allowed. Despite this fact, high data rates must be transmitted without losses. If communication occured via light in the surgical room, it would be possible to control wireless surgical robots or transmit x-ray images. In airplanes, each passenger could view his own entertainment program on a display, saving aircraft manufacturers miles of cables. Another possible venue for the application of this technology are production facilities, where radio transmissions often interfere with industrial processes.
One disadvantage is that as soon as something gets between the light and the photodiode (for example, when someone holds a hand over the diode) the transfer is impaired.
The scientists emphasize that VLC is not intended to replace regular WLAN, PowerLAN or UMTS. It is best suited as an additional option for data transfer where radio transmission networks are not desired or not possible--without requiring new cables or equipment. Combinations are also possible, such as optical WLAN in one direction and PowerLAN for the return channel.
Posted by John Wallace
From here...
The weak link seems to be currently it would have to use some other type of connection for the up-link. That could be overcome with a purpose built bulb that would incorporate a photo-detector I am sure.
It seems like this would be best suited to power companies who provide BPL service, as far as consumer use goes.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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Annafan
Member (Idle past 4579 days)
Posts: 418
From: Belgium
Joined: 08-08-2005


Message 23 of 32 (631111)
08-30-2011 11:46 AM


Once it starts to transmit information, people will get sick of it. How long before some people will acquire a "LED sensitivy syndrome" that causes CFS?

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 24 of 32 (631118)
08-30-2011 12:02 PM
Reply to: Message 23 by Annafan
08-30-2011 11:46 AM


CFS? I can't find any link between Chronic Fatigue Syndrome and light or better yet modulated light.
quote:
Chronic fatigue syndrome has generated significant debate and controversy in the medical community. It remains a poorly understood and potentially debilitating illness. Scientists believe chronic fatigue syndrome is not contagious and that multiple factors including immunological, genetic, environmental ones working in combination cause the development of chronic fatigue syndrome. Laboratory tests (blood, urine, etc.) are of little value in diagnosing the syndrome.
From here...
It seems they don't know much about it, yet you suggest a new, relatively untested technology may cause/contribute to CFS?
I would suggest that it more likely to cause seizures in people who have epilepsy, we know modulated light can do this already.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 25 of 32 (634451)
09-21-2011 6:15 PM
Reply to: Message 24 by fearandloathing
08-30-2011 12:02 PM


It seems they don't know much about it, yet you suggest a new, relatively untested technology may cause/contribute to CFS?
She's referring to the people who claim to have "wifi sensitivity syndrome" or whatever; they claim to have CFS-like symptoms that are exacerbated by the transmissions from wifi devices (and sometimes cell phones.)
It's been on the news recently because people who imagine that they suffer from this are moving to the United States National Radio Quiet Zone in West Virginia, a 13,000 square-mile zone where such radio transmissions are forbidden by law (to avoid scrambling the reception of the Green Bank Radiotelescope.)
Anything new, and some people will imagine that they're "allergic" to it. For instance, MSG. (There has never been a recorded case of MSG allergy but I imagine you probably know people who think they're allergic to it.)

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ramoss
Member (Idle past 612 days)
Posts: 3228
Joined: 08-11-2004


Message 26 of 32 (634516)
09-22-2011 10:26 AM
Reply to: Message 25 by crashfrog
09-21-2011 6:15 PM


I don't know if it could be considered an allergy, but I do know several people who have to avoid it because it often triggers migraines.

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 27 of 32 (634518)
09-22-2011 11:11 AM
Reply to: Message 26 by ramoss
09-22-2011 10:26 AM


Really?
I don't know if it could be considered an allergy, but I do know several people who have to avoid it because it often triggers migraines.
Just WiFi?
As a radio enthusiast I find that hard to believe. Microwave ovens, some cordless phones, baby monitors, amateur radio, Bluetooth....the list goes on...all use the 2.4GHz band. Your friend would have a perpetual headache if this were true.
Most people never stop to consider how much RF you are exposed to all day. If you had access to a RF spectrum analyzer you might be shocked at the amount of RF you are currently sitting in, especially if you live in an urban area.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 28 of 32 (634541)
09-22-2011 12:51 PM
Reply to: Message 27 by fearandloathing
09-22-2011 11:11 AM


Re: Really?
Just WiFi?
I'm pretty sure that comment was meant to be about MSG, not about WiFi.

Fundamentalism - the anti-American, anti-Christian branch of American Christianity

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fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 29 of 32 (634545)
09-22-2011 1:48 PM
Reply to: Message 28 by nwr
09-22-2011 12:51 PM


Re: Really?
LOL, Thanks
That makes much more sense, I am a moron more often than not. (probably from exposure to high levels of RF) I can see it maybe screwing with your blood pressure and causing headache, I try to avoid salt and msg in food I buy.
Edited by fearandloathing, : No reason given.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

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ramoss
Member (Idle past 612 days)
Posts: 3228
Joined: 08-11-2004


Message 30 of 32 (634589)
09-22-2011 10:31 PM
Reply to: Message 29 by fearandloathing
09-22-2011 1:48 PM


Re: Really?
I did mean msg. Allergic to wi-fi... Hardly.
Florecent lights can cause headaches with some people.. I am sure they are stocking up on the incandecent bulbs..

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