Sending The Internet From An LED Lightbulb

The number of things that can carry Internet traffic is always increasing. Now, you can add LED light bulbs to this list, as engineers in Disney Research have just demonstrated a system that transmits Internet traffic using an LED light bulb. This method of communication isn’t new: Visible Light Communication (VLC) has been demonstrated before by Disney and others, but this project puts it into a standard LED light bulb. This bulb has been modified to include an Atheros AR9331 SoC running OpenWRT and an Atmel ATmega328p that controls the LED elements and sensors that send and receive the data. So, the device is acting as a gateway between a WiFi network and a VLC one.

Disney’s new test system (PDF link) isn’t especially fast: it can only carry about 380 to 400 bits per second, so it won’t be streaming video anytime soon. That is definitely fast enough, though to send control data to a toy, or to send a continual stream of updated data to a device in the room, such as an ebook reader with a continually updated encyclopaedia. This being Disney, the authors coin a new phrase to end their paper: The Internet of Toys.

46 thoughts on “Sending The Internet From An LED Lightbulb

  1. Apart from the fact that this has been done before, I wonder what sort of health implications this might have, hopefully none. But especially for pets that people have, which might be more sensitive to IR than we are.

    It will be cool once this tech gets speedier, though. Although I’m sure anti-IR people will come out to replace the anti-Wifi people.

    1. @Xtremgamer – I watched Harald Haas’ presentation and demo and I assure you it is NOT “old tech”. His proprietary system is light-years (pun intended) from old tech. It uses parallel streams of light data to support a HD video! He’s not explaining HOW for obvious reasons. He’s oversimplifying it and he does have a thick German accent. So it’s easy to miss things in his presentation. This is not some AM modulation of a single LED. They are probably using PCM of each LED with different parts of the serial or parallel data stream. It’s kinda revolutionary like Tesla’s and Bell’s gadgets.

      However, Harald made the same mistake Nikola Tesla did with his power transmission idea in early 1900’s. He told the fat-cats that you don’t need to put a “meter” on it so the power was free to all. Harald is talking about eliminating pieces of telecom infrastructure. That LAST MILE thing is BIG MONEY (sacred cow stuff?)! AT&T (aka Frontier), COX, BT, Telstra, etc. probably don’t want this VLC stuff. AT&T (American Telegraph in 1800’s) didn’t want Bell’s early-VLC-based 1880’s Photo Phone idea let alone his telephone idea they tried to steal and market as their own.

      I guess it eliminate jobs, and takes away money from the fat-cats. That’s TABOO in today’s marketplace. Anything that’s “revolutionary” must come from THEIR IP (intellectual Property). If you’re an engineer working under their aegis with their equipment, you try and patent anything on your own, you’re in trouble. THEY want the IP and THEY will get it by any means necessary.

      Case in point: Look what happened to AT&T’s Walter L. Shaw. He was the father of many telephonic devices you take for granted today that you thought MA-BELL invented. No Walter did (i.e. speaker phone etc). Google what happened to him.

      I hope Harald did not fall into that same trap. What ever became of this VLC idea of his? What’s Disney doing with it? Did they get his patent licenses for it? Is he working with them? If Disney has it then it could prove fruitful as they tend to pioneer new stuff for the world. Check out EPCOT for examples.

    2. His explanation for security is laughable. Sure, light does not travel through walls, but that does not mean that the room is light-proof. The gap under the door, the window, and whatnot will leak light.

      1. @TacticalNinja – TRUE! But old school photographers know how to make a dark room. Old methods to protect photo sensitive paper or films from being exposed to extraneous light. I think you’ve just invented the anti-photonic SCIF (Sensitive Compartmented Information Facility)!

    1. I don’t think children nor their parents want toys connected to the power line in order to communicate. Imagine Star Wars toys that can communicate to each other and to the Internet when in the same room as this light bulb. That’s what Disney is looking into.

        1. @fhunter – No – there’s no wi-fi involved here (I think). The VLC bulb converts the power-line Ethernet communications from your home router which has a power-line communications bridge to dump data to all VLC bulbs in the house. The visible light from the bulbs is converted back to data in your laptop, smartphone, or tablet via the web camera or a outboard photo diode receiver. Ideally they want to use your smartphones flash for the camera to send VLC data BACK to your router some how. That part I can’t figure out just yet. Not sure they have either. Maybe there is an outboard photo diode device mounted near or IN the bulb? Not sure.

          So far I think the Disney VLC device is one-way just now. Maybe they are working on a 2-way system? The TED TALK video in OP talks about this back in 2011. They must have made progress in 4 years by now. The TEDTALK video demo’d a HD video VLC link. Wi-Fi has better range (300 or more feet), VLC is only a few feet but the BW is larger and not crowded at all in your house! VLC won’t penetrate walls like Wi-Fi but that only enhances security – according to them.

          1. @fhunter – I wouldn’t think DISNEY or any R&D operation would use PLC (power line communications) for experimentation. It’s too unstable for reliable comm. However, Harald Haas was pushing for PLC for his bulbs back in 2011 because it makes the comm channel simpler for him and end-users versus stringing several hundred feet of Cat 5 cable around your house. And remember if you us Cat 5 you still need to supply power to the bulb from a second cable to the outlet. PLC kills two proverbial birds with one stone.

    2. I have a pair of power line Ethernet link devices. There OK but they loose link when the home power line is too noisy or too many surges and ebbs. You can’t use a filtered outlet strip either. I think you’ll have to remove all fluorescent lamps and power line intercoms from the house too. They are the worse power line noise makers I think. The power utility companies uses them for intra-utility-communications on main power line but they are using higher-power I think. The higher power allows for bridging across transformers I speculate. Not sure if that will introduce any noise to your PL system at home.

      I like the idea of using PL comm with these Li-Fi bulbs. I hope it works out OK for the manufacturers and not a fail for them as FSO communications turned out in late 90’s and early 2000’s. I really like this VLC system. I want to see all forms of VLC, FSO, etc. become mainstream and not just behind-the-scenes technology. Alexander Graham Bell invented it in 1880’s but erroneously thought it would be a complete fail compared to his new telephone invention (Google Bell Photo Phone). If only he knew…

      1. I have only seen the power line adapters, haven’t used them in practice. Your observation is valuable and interesting.
        Power line intercoms? Wow, of that I haven’t heard. Sounds quite dangerous and potentially shocking :).

        1. @fhunter – Yeah Powerline Ethernet adapters come in handy where you are not allowed to run CAT-5/6 in your home (i.e. tenant in apartment building?). But the power line can get noisy and mess up your signal. You have to mitigate it some how without putting filters in between the adapters as they are using a form of RF energy injected into the 110VAC (USA). The filters will filter that out defeating your 2 adapters. So you have to track down the noise offenders. In an apartment building you may not be able to do anything about the lady below your apartment running her blender and screwing up your web surfing. And forget about the CB or HAM radio operator next door trying to reach Australia on his rig. That will knock out the VLC’s too. I don’t think PL Comm is a good idea now…

          Yeah Radio Shack sells power line intercoms. They SUCK! So don’t buy them. However, their discontinued 800 Mhz coded radio version works much better. However, radio scanners can listen in to you telling your kid to turn down the rap music! Or asking someone to bring you a coffee to your lab… (LOL) – who cares let ’em listen…

          I like the VLC idea but they need to eliminate the PL Comm and just use Cat 5/6 Ethernet cables or coax and BNC connectors like the old 10-BaseT days (OSI: physical layer stuff). Also I can’t see how 1-way is valuable for anything. They need an VLC up-link method too. Unless they are using Wi-Fi for uplink and VLC for down-link. That’s how the US NAVY SLC system works. Subs can’t talk UP the beam only listen and reply via a different RF channel. For now that is, I’m over-simplifying it a bit for obvious reasons… you can Google it for more. (i.e.:QinetQ SLC)

  2. A LED’s usefulness as a source of illumination is inversely proportional to it’s use as data channel.

    It would be much easier to just add a special IR LED to the module along side the visible light components. But even then you need a dedicated driver and it will be very sensitive to heat.

    A discussion about how to do it, from 3 yeas ago,

    All that aside I wonder if the LEDs on a computer and keyboard can be used by malware to leak data….

    Of course they can, and with a bit of a hack they become a full I/O port.

    This has been possible for decades, and yet there is no mention of it in the a certain collection docs.

    1. @Dan – There once was a telescope and photo-diode hack to use the DATA LED on a standard modem to monitor a serial communication. However, that was the old slower data rate days. Today I don’t think it would work with Ethernet data rates. I do know that “certain people” use techniques to get your I/O via something called Van Eck Effect (Google TEMPEST). It has evolved light-years since 1985 when he first demonstrated it. There is another more sophisticated technique but is so complicated I’m not sure “they” have the IT resources to pull it off. It involves somehow measuring the power anomalies of your CPU and converting that into intercepted data. It was showcased here on HaD somewhere. I forget the name of it right now. Oh OK I remember now: Chip Whisperer – however you have to get darn close for it to work.

      The latest gadgets by them can be Googled: ″AirHopper″, “BitWhisper”, and “GSMem”. The last one will BLOW YOUR MIND! I did not know they could do this! Of course OUR boys and girls (USA) did not think this one up. It was the usual suspects over their east of the Mediterranean Sea. I think ChipWhisperer was one of ours though. Very complicated system. (Oops! No Colin O’Flynn is Nova Scotia Canada’s boy not ours!) :-)

      1. If I have time later today I’ll post a little BASH script that sends Morse code out through the Scroll Lock LED on your keyboard. You can pipe the output of any other command through it and that means if you have got root on the box you can send anything. It works because, well when was the last time you ever saw Scroll Lock being used? Some of the other LEDs on newer PCs are very powerful, I have blue ones on mine that light up the room and cast clear shadows at night.

      2. here you go:

        # txt2morse2LED
        # version 0.1
        # licence GPL 3.0
        # A simple demo of leaking data out the LEDs on a keyboard
        # May have some use as a status indicator.
        # apt-get install morsegen

        xset -led named ‘Scroll Lock’


        # define our functuions
        dot () { xset led named ‘Scroll Lock’; sleep .5; xset -led named ‘Scroll Lock’; }
        dash () { xset led named ‘Scroll Lock’; sleep 1.5; xset -led named ‘Scroll Lock’; }
        gap () { xset -led named ‘Scroll Lock’; sleep 3; }

        # test if file name supplied
        [ $# -eq 0 ] &# test if file exits else warn and exit
        [ ! -f $INPUT ] &# the while loop, read one char at a time
        while IFS= read -r -n1 c
        m=`echo “$c” | morsegen -` # get our file contents as morse ( . -)
        for (( i=0; i<${#m}; i++ )); do # loop through morse sequence for character and toggle LED
        case "$mm" in
        ' ')
        sleep .5 # wait a bit before next dot or dash
        done < "$INPUT"

        xset -led named 'Scroll Lock'

        1. @Dan – That’s actually quite cool. I wish I could convert that to Javascript. I would need the poke/peek commands for a PC/laptop. I found this really cool Google Play app for sending and receiving Morse using your phone’s flash and camera. Just don’t have any non-Luddites in my family to play with it with me… 8-)

          Also seen a PSK app that does 2-way data too over a duplex audio channel. Still have no application for it other than idle hobbyist playing around.

          1. Not sure how you would do the xset stuff under windows, but you can make windows run bash shell code,

            I also have a version that runs 100 times faster, but that is unreadable, by humans.

            Anyway it is just a demonstration of the point I made, that most computers have contained LED based covert output ports for decades.

            For proof that you can do input as well as output with LEDs see this paper, Where the paper has a finger controlling the light level it could also be another LED held near the LED on your PC or keyboard, if the right circuitry is in place (that is the bit you have to hack.). But once you mod a keyboard nobody would notice the difference, the I/O would hide in plain sight.

          2. @Dan – AMAZING! So Scott Hudson from CMU says reverse biasing a common LED turns it into a rudimentary light sensor? When did he publish this? I can’t find any date. He also says it was common knowledge. Among who? Not sundry electronic technicians of our day. I think we all thought reverse-biasing an LED would kill it or degrade it, Who would have thought you could use them as a 2-way VLC device? Amazing!

  3. Can’t wait for these to be produced as imagine the fun we can have with Binaural beat brainwave entrainment, actually imagine the security implications of hacking one, sending rogue controls to it and manipulating the mood of people sitting under the lights.

    Sending communications via light is really nothing new, I remember years ago I had a watch that you held against the CRT monitor, the face of the watch had a sensor and the application on the screen of the monitor sent data to the watch. was a cool toy :)

    1. @Boris van Galvin – “…Binaural beat brainwave entrainment…” – You mean like this?

      Yes, I had one of those watches too. It had a tiny lens in the face. They evolved to USB downloadable apps to a watch grandchild by same company. You can see them at the Timex watch museum in Waterbury CT right off of I-91 highway. They have a huge Moai statute from Easter Island out front. I freaked out a paranoid dude with it once inadvertently. He swore it was a wrist camera. I had to pull it up on the Internet to prove it wasn’t. Great for keeping appointments.

      How can I get that beeper watch from the movie Man on Fire (2004), where Denzyl Washington wore a watch called a Casio “Pathfinder 227”? He says to the bad guy before activating the watch: “Last wish? I wish you had more time.” 8-)

  4. Harald Haas is presently at the University of Edinburgh Scotland and is a professor there. He is presenting his technology worldwide and at least two companies have spun off (pureVLC and PureLiFi). People’s Republic of China are exploiting this technology too after he gave a presentation there not too long ago.

    Disney is researching this in Zurich Switzerland NOT USA. Here is a PDF paper they published on the subject:

    1. @Ivo Simicevic – Yes true Ivo but NOT like this. Professor Harald Haas has developed a revolutionary method of VLC using Orthogonal frequency-division multiplexing (OFDM) is a method of encoding digital data on multiple carrier frequencies. He is pioneering a new type of VLC. He even has other innovations like providing VLC while also providing wireless power via a solar cell arrangement. Like using a Q-Beam spotlight to send self-power to the array and also modulating the same light with multimedia. BRILLIANT!

    1. @skaarj – Yes that thing was awesome. It was invented at Carl Zeiss optics at Jena in 1930’s. It was based on Alexander Graham Bell’s Photo Phone only more evolved. They used it secretly for U-Boats to coordinate attacks during WW2 against the allies. Also it is rumored that NAZI tank commanders used them too. The ALLIES had no idea they were in use. However, thanks to intrepid OSS operatives it was eventually discovered and the Brits and Americans were working on their own versions. There were different versions, some could operate at longer distances. They used infrared and visible light to do 2-way communications secretly. This was actually better than ENIGMA as NO ONE was listening to them at Bletchey Park!

      Here is a video of a LiSpr80 in action (actual recordings start at time stamp 4:00):

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