back to article Meet ELIoT – the EU project that wants to commercialize Internet-over-lightbulb

A consortium of European organizations has launched ELIoT, an EU-funded project that hopes to develop commercial applications for visible light communications. The project’s primary concern is Li-Fi – a method of short-distance data transfer that relies on the light spectrum and fancy LEDs rather than radio frequencies, …

  1. Blockchain commentard

    So what happens when 2 people in the same room want to use the internet? Do they get each others websites (awkward!!).

    1. Hans Neeson-Bumpsadese Silver badge

      So what happens when 2 people in the same room want to use the internet? Do they get each others websites (awkward!!).

      Actually, I think conventional wisdom would have it that reliability would increase with more people in the room.

      Many hands make light work. you were....

      1. David 132 Silver badge
        Thumb Up

        Hans Neeson-Bumpsadese Many hands make light work

        That is one of the most dreadful puns I have ever read on the Register, and you should be deeply, deeply ashamed of your lack of self-control.


        1. AceRimmer1980


          Pwn home.

          1. Psmo

            Re: Eliot..


      2. Anonymous Coward

        It's obvious that this project needs more people from the Netherlands on it. Because many Hans make light work.

      3. martinusher Silver badge

        So what happens when 2 people in the same room want to use the internet?

        Same thing happens with wireless. That's what protocols are for.

        Most people seem to have forgotten that the original use for 802.11 was allowing computers to communicate using infra-red light. This interface was common on 90s laptops and was the reason for WiFi having its 'ad hoc' mode of operation that didn't use an access point as such.

        1. Michael Wojcik Silver badge

          Re: So what happens when 2 people in the same room want to use the internet?

          This interface was common on 90s laptops

          And very popular on the Palm Pilot, which for a short time was nearly ubiquitous among gadget fans in the US. I recall family get-togethers where groups of cousins would be cheerfully beaming contact details at one another.

          I still have a Palm Pilot Titanium lying around somewhere (I may see if I can get it working for a little retrocomputing fun one of these days), and I believe I still have at least one working laptop with an IrDa interface.

    2. AMBxx Silver badge

      Same as happens when 2 people on the same piece of wire want to use the internet at the same time.

      1. Doctor Syntax Silver badge

        Or on the same WiFi access point.

      2. David Hall 1

        Dumb reg readers

        Tdm. Google is your friend

        Bigger issue will be watching porn late at night without waking up everyone in the house by turning the lights on.

        1. Michael Wojcik Silver badge

          Re: Dumb reg readers

          A bit of research suggests LiFi developers are also using, or working on, at least WDM and OFDM as well.

          And pretty much by definition LiFi uses spatial multiplexiing, since it's confined to line-of-sight. Every room is its own segment.

          But that's the thing with multiplexing: you start with dividing in one domain, and pretty soon you're dividing in half a dozen. It's just too much fun.

    3. Anonymous Coward
      Anonymous Coward

      Modulation probably.

    4. Psmo

      There's a modern invention calling the zoetrope that would probably help.

      Or waving your hands really fast in front of the light.

      And ask a mate to thump the wall to add ambience.

  2. Mike 125

    'Unlightly' to happen.

    >Li-Fi is not susceptible to electromagnetic interference

    Yes it is. It's just that there is none at that frequency, for now. The Long Wave radio band didn't used to have interference.

    >why aren’t we using it?

    It appears to be a solution looking for a need.

    1. ibmalone

      Re: 'Unlightly' to happen.

      Long wave penetrates buildings though. Light stops at walls, or even heavy fabric, so there's less spillover. (Also the potential bandwidth at those frequencies is enormous, but really we're limited to just switching on and off.)

      1. Francis Boyle Silver badge

        Re: 'Unlightly' to happen.

        Not if you live in a one of these. For some reason they're big in japan.

      2. Nick Kew

        Re: 'Unlightly' to happen.

        Long wave penetrates buildings though. Light stops at walls,

        I take it you're not a windows user?

        (if only for an excuse to use that icon).

        1. Anonymous Coward
          Anonymous Coward

          Re: 'Unlightly' to happen.

          Ewww Windows.

          You need to constantly clean those.

          Doors are better.

          I use Arches, btw.

    2. AMBxx Silver badge

      Re: 'Unlightly' to happen.

      Somebody's shadow probably counts os interference too.

      1. ibmalone

        Re: 'Unlightly' to happen.

        I'd think the technology should deal with that, depending on your switching speed. In a room with a single lightbulb you can still see in the shadows due to scatter. This leads to multi-path dispersion in fibre-optics and smears out the signal (it's better regarded as phase velocity effect, but hey-ho), but distances within rooms are short and likely you can adjust sensitivity to get the strongest-path signal only.

    3. Dr Dan Holdsworth

      Re: 'Unlightly' to happen.

      Actually, we're steadily heading in this direction already. 2.4 GHz wifi penetrates walls quite well, 5 GHz has better bandwidth but much less range, and 5G mobile telephone signals are even higher frequency and penetrate solid objects even less well.

      Skipping a section of the EM spectrum and moving on to near infrared or visible spectrum is just a logical next step, which would once again increase the possible bandwidth and would allow/force more transceivers to be put in close proximity.

      1. hplasm

        Re: 'Unlightly' to happen.

        I'm getting some random spam from my gas fire!

        1. DJV Silver badge

          Re: 'Unlightly' to happen.

          You want to make sure you haven't got an infestation of Vikings.

      2. 96percentchimp

        Re: 'Unlightly' to happen.

        IIRC 5G is being employed from 700MHz up to the high GHz range, depending on the environment and use case. It's not tied to a slice of bandwidth, and in time the operators will probably want to re-use their current 3G/4G spectrum for 5G, just as they have with some of their 2G bandwidth.

    4. John Sager

      Re: 'Unlightly' to happen.

      Very localised i.e. one room in practice. I wonder which will take that market first (if there is one) LEDs or 60GHz radio?

    5. Anonymous Coward
      Anonymous Coward

      Re: 'Unlightly' to happen.

      Except for me with my halogen lightbulb suit....aahahahahahahhahaahaa!!!

    6. Mage

      Re: 'Unlightly' to happen.

      It's been around since the 1980s. It's basically line of sight and more expensive to install than WiFi Airpoints. Also it was about 2003 was when laptops stopped including optical communications?

      It's very niche, so few laptops, tablets & phones will include it. Also efficiency for generation of optical signals is pathetic compared to 800MHz to 6GHz (Mobile & WiFi).

      1. Jellied Eel Silver badge

        Re: 'Unlightly' to happen.

        It's been around since the 1980s. It's basically line of sight and more expensive to install than WiFi Airpoints. Also it was about 2003 was when laptops stopped including optical communications?

        People of a certain age might remember the BBC's Micro show, complete with blinking box in the corner of your TV screen that you could read with a light pen/sensor to dowload code.

      2. Brewster's Angle Grinder Silver badge

        Re: 'Unlightly' to happen.

        "It's very niche, so few laptops, tablets & phones will include it. Also efficiency for generation of optical signals is pathetic compared to 800MHz to 6GHz (Mobile & WiFi)."

        All phones, many tablets, and some laptops have optical sensors. In the modern parlance they're termed "cameras".

        Angel because their halos would provide interference.

    7. Daniel von Asmuth

      But soft what Li-Fi through yonder window breaks

      "Li-Fi is not susceptible to electromagnetic interference"

      ....except maybe the light of our old sun. Our eyes would notice when a LED starts transmitting... A spy could tap of LiFi signal through a window.

      Why not use IrDA or something that works better under water.

      1. 96percentchimp

        Re: But soft what Li-Fi through yonder window breaks

        Having seen Li-Fi in operation, I can confirm that you don't notice a thing. At, least, human eyes don't register the flicker at that speed.

  3. Pascal Monett Silver badge
    Paris Hilton

    So we are going to have flickering streetlights everywhere

    Are streetlights going to become Internet hotspots then ? Or will the streetlamp just relay data from its neighbors ?

    Are you going to be able to pirate a streetlamp signal and send anything you wish in an untraceable manner ?

    And when you've reached the last streetlamp, where does the signal go then ?

    I think there is still a lot to think of concerning this technology.

    1. simonb_london

      Re: So we are going to have flickering streetlights everywhere

      Probably the exact opposite. We will no longer have flickering street lights because the current 50/100 Hz flicker is due to rubbish LED driving circuitry. If it has to be an advanced driver that pulses the LEDs at a much higher frequency than anyone can see then the 50/100Hz will disappear in the process.

      1. Flywheel

        Re: So we are going to have flickering streetlights everywhere

        Our cash-strapped Council will love that - they've spend millions buying new LED streetlights and now they'll need to change components!

      2. Psmo

        Re: So we are going to have flickering streetlights everywhere

        That's going to be prohibitively expensive for Councils.

        If they can get the mobile operators to support the rollout and lease the infrastructure it could be interesting, though.

  4. Headley_Grange Silver badge



    1. Anonymous South African Coward

      Re: interference-free?

      Or Bruno the Big Ugly One eclipsing the light*...

      *assuming that it need to have LOS to the light source.

      What about reflections from mirrored surfaces?

    2. Nick Kew

      Re: interference-free?

      Damn you for getting in first with that. I was thinking through how to recruit moths for espionage!

    3. Solviva Bronze badge

      Re: interference-free?

      Let me get that double slit out my pocket to give you some interference

      1. Rich 11

        Re: interference-free?

        Said the actress to the bishop.

  5. David 132 Silver badge

    First radio, now light...

    Is it just me, or are communications technologies appearing with increased frequency?

    1. Jedit Silver badge

      Re: First radio, now light...

      Boo this man. (Then optionally upvote him.)

      I think my main concern with this technology is how to stop the signal being blocked by, for instance, someone walking between the transmitter and the receiver. But I'm sure that's been thought of, I just haven't read around the subject yet.

      1. Balding Greybeard

        Re: First radio, now light...

        @Jedit, me thinks that line-of-sight requires ceiling mounts like most offices do today for WiFi. Question is, how many LiFi transmitters are required? And then I think of my Sammy TV remote, it uses infrared transport which bounces off just about anything.

        Too often, I pickup the remote without looking at the orientation and try changing channels. When I realize the channel numbers are going down rather than up I figured the signal is probably bouncing off my great beer belly.

        1. Doctor Syntax Silver badge

          Re: First radio, now light...

          The thing about your IR remote is that the actual signal on the IR carrier is quite low frequency. What happens when you ask it to transmit a GHz signal?

          You'd be sending out a pulse of light about a foot long (Grace Hopper used to hand out nanoseconds - pieces of wire about a foot long). It would be OK with a direct line-of-sight signal dominating the reflections. Block that and the various reflections of your nanosecond pulses will arrive over a period of tens of nanoseconds.

          1. Mage

            Re: First radio, now light...

            You'd struggle to do 0.002 Mbps on an IR remote system. Manchester encoding at less than 1 kbps using 38kHz OOK of the IR. Makes it quite immune to noise and allows high sensitivity. You'd need about 10,000x power for same performance from ethernet speed optical communications.

        2. Psmo

          Re: First radio, now light...

          My latest decoder has a remote that goes has the option of connecting through WiFi, so it will work through walls.

          Weird to have a remote that needs software updates though.

      2. THMONSTER

        Re: First radio, now light...

        Make that light powerful enough and it will burn straight through any interference.

        Icon: this is probably going to be the result when someone at the back of a crowded room needs to use the wifi.

      3. Teiwaz

        Re: First radio, now light...

        I think my main concern with this technology is how to stop the signal being blocked by, for instance, someone walking between the transmitter and the receiver.

        There was an episode of Max Headroom : Twenty Minutes into the Future, where Bryce was experimenting with high power lasers for communication purposes

        So high power, they could supposedly bisect anyone walking through the beam...

        It wouldn't stop anyone, but they wouldn't do it again.

        1. Psmo

          Re: First radio, now light...

          It would avoid the problem of people pinching and damaging the cables.

          You'd need more cleaning staff though.

    2. Warm Braw Silver badge

      Re: First radio, now light...

      That's so bad it hertz

      1. AceRimmer1980

        Re: First radio, now light...

        Starting to get baud now.

      2. Flywheel

        Re: First radio, now light...

        > That's so bad it hertz

        If they used a laser it would be killer-hertz

    3. Grooke

      Re: First radio, now light...

      You might be onto something. Maybe we can transmit information by voluntarily changing the frequency at which we produce new communication technologies.

  6. BinkyTheMagicPaperclip

    'Interference free'

    It might not interfere with the Li-fi communication, but it might cause interference in the first place. I only buy decent (Philips) LED bulbs, as the no-name ones interfere with other equipment.

    It's also going to be a pain when the bulb dies, the lifetime is always predicted based on limited usage per day and perfect wiring. If your wiring is less than optimal, expect the lifespan to be dramatically less.

  7. JDX Gold badge

    It's a neat idea but as someone commented, I'm not sure it solves a problem - sounds more like something you'd do as a school project!

    I was curious what sort of speed/bandwidth this might deliver, is it viable for replacing WiFi or intended for much less demanding background stuff?

    1. albertfandango

      Having a very peripheral involvement in this a few years ago, the working LiFi kit ~2014/15 was approximately equivalent to 802.11b. Presumably things have moved on significantly from then.

    2. Balding Greybeard

      Wired is the Best

      I once rented space in an old meat warehouse converted into a multi-tenant office building. So many neighbors, so many WiFi signals. Equals too many collisions. Equals no throughput.

      Mounted 1” conduit on the wall, with 2-CAT-5 drops by every desk, equals wonderful throughput. And multi-line phones at every desk.

  8. steelpillow Silver badge


    IrDA does pretty much exactly this with infrared. According to Wikipedia, "IrDA was popular on PDAs, laptops and some desktops from the late 1990s through the early 2000s. However, it has been displaced by other wireless technologies such as Wi-Fi and Bluetooth, favored because they don't need a direct line of sight and can therefore support hardware like mice and keyboards. It is still used in some environments where interference makes radio-based wireless technologies unusable." I couldn't have put it better myself (although IrDA lends itself to dark humour better than Li-Fi does).

    Li-Fi would seem to have much the same issues, topped with an established rival in the few environments where it is appropriate.

    1. Keith Oborn

      Re: IrDA

      From my memory of IrDA the problem was desperately short range - you had to put the two little black panels within an inch or two of each other. So presumably very limited power. However, it's evident that this *can* be done: almost all consumer electronic remotes are IR. OK, data rate is trivial. However, they are still quite directional, but that may be by design.

      Basically sounds like a bright idea. But if we all have to buy new LiFi light fittings (ant bets?) not so good.

      I can see advantages in shared spaces: hospitals, shopping centres, etc, where there is usually fixed lighting from multiple sources and often quite a bit of electrical noise. WiFi range can also be a problem.

      HMM: we all forget these technologies have to be bi-directional. Does than mean my laptop (phone!) has to have a light bright enough to be seen by a detector 100m away? What happens when the phone's in my pocket?

      1. AMBxx Silver badge

        Re: IrDA

        You could avoid the need for new light fittings if all the bulbs contained a wifi receiver - they could just flicker in one direction and wifi in the other.

        Then again, you could just use wifi and forget all about this!

      2. Anonymous Coward
        Anonymous Coward

        Re: IrDA

        Either your memory or your hardware was faulty. Psion 5 to HP printer (LaserJet 6?) worked from several feet away. Psion to phone was usually inches away, but only because I wanted the phone within easy reach. Getting any of these to work reliably with Windows was another matter entirely, and I suspect this is where IrDA's reputation for unreliability came from.

        1. Mike 16

          Re: IrDA

          Not sure it was exactly IrDA, but I recall when every hallway was infested with people "beaming" stuff between Palm devices. Not long distance, but capable of traversing at least two sheets of glass, as seen in the Palm "Train Ad":

      3. albertfandango

        Re: IrDA

        > But if we all have to buy new LiFi light fittings (ant bets?) not so good.

        True, but for new buildings or major refurbishments this is less of an issue.

        > Does than mean my laptop (phone!) has to have a light bright enough to be seen by a detector 100m away?

        This was explained to me a while back: Data transmission is achieved by modulating the light levels very quickly (rather than simple on/off). It can therefore operate in very low light levels (invisible to the human eye) albeit with a bandwidth penalty. Still, this would allow the system would operate in a “dark” building.

        > What happens when the phone's in my pocket?

        Nothing :) Seriously though, I don't think personal mobile devices are likely to be viable for this kind of technology, but I could be wrong...

    2. VonDutch

      Re: IrDA

      Ah, the halcyon days of IrDA on a Nokia 7650. Share your GPRS connection with another device as long as it's within a couple of centimetres and nothing moves.

      Give the option of using it as a TV remote too!

      1. Dan 55 Silver badge

        Re: IrDA

        I think the first Mission Impossible film's third act was based around this very thing... trying to get an IrDA connection to work while on the train.

        1. Jamie Jones Silver badge

          Re: IrDA

          I used to use the infra red thingie on my nokia 9110 communicator with the work laptop the other side of the room, over 6 feet away. Worked fine as long as no-one stood in the way!

          1. Mike 16

            Alternative uses

            A friend was curious about the "universal remote" capabilities, and stumbled across a source of fun.

            Seems that some (many?) of those scrolling LED signs used in many businesses are controlled with some sort of IR comms. This was during the period that there were bank branches, and enough folks who used them to have lengthy queues.

            As usual for "connected thingies", there was no security, so he would while away his time in the queue by changing the signs on the wall behind the tellers to something like

            "Ask about our .1% 30 year mortgages".

    3. juice

      Re: IrDA

      > According to Wikipedia, "IrDA was popular on PDAs, laptops and some desktops from the late 1990s through the early 2000s

      I remember going to some BT Expo thing back in the late 90s, and they were demo'ing some fancy City Trader desk with an I/R network hookup - there was a big "drainpipe" tube at the back of it, which was meant to communicate with a sensor in the ceiling.

      These days, it's all about nanosecond transactions and any humans still in the process are pretty much just window dressing for Skynet, so the idea of using any wireless technology is out the window. Still, it did look impressive :)

    4. GlenP Silver badge

      Re: IrDA

      IrDA had its uses but could also be a pain in the proverbial.

      Many years ago I used it to connect the fairly ancient laptop to the Nokia phone, due to incompatible voltage levels the alternative serial cable only worked if the laptop was on mains and fully charged. It did mean I could dial in to the office and run the month end processing from my tent but there was a huge issue with electromagnetic interference to the signal - caused by the sun! Had to put the phone by the laptop and cover the connection.

      Sat on a training course a few years later we discovered the many corporate standards didn't include having the IrDA port on the same side of the laptop so my machine and the one belonging to the person next to me kept trying to communicate until we built a mini-wall between them.

  9. RDW

    "It could also be more secure: no chance of hackers infiltrating the network, if they need to be in the room to access it."

    Apparently hackers will still be able to exploit vulnerabilities in Windows...

  10. Jc (the real one)

    What happens when someone leaves the room and turns out the all of the devices go off line?


    1. albertfandango

      On the LiFi kit data can still be transmitted at light levels invisible to the human eye, so presumably if/when you flicked a wall switch the relevant bulbs would switch to an invisible light/low bandwidth mode as required.

      Although I suspect mere mortals wouldn't be allowed anywhere near lightswitches in this kind of building-of-the-future.

    2. Arthur the cat Silver badge

      What happens when someone leaves the room and turns out the all of the devices go off line?

      The system modulates the dark. What, you've not heard of dark solitons?

  11. alain williams Silver badge

    Looks as if Harald Haas

    had a real light bulb moment

  12. Zog_but_not_the_first

    Interesting development

    Any chance of a flickering box in the corner of my TV screen so I can load programs apps onto my Spectrum tablet?

  13. TeeCee Gold badge

    Obvious drawback.

    The bulbs will, inevitably, be astonishingly expensive, the rewiring for the infrastructure to support them won't be cheap and you'll have to do every bloody room....including the bog and the cupboard under the stairs.

    This is better than plonking a wireless access point in one place how exactly?

  14. Steve K

    Hmm - what if the lights are off....?

    Presumably this means that you will need your lights on all the time, unless you only use WiFi at night.....

    In many office/public building environments I imagine that this will not necessarily be an issue, but how about other use cases (streetlights, home)

    1. albertfandango

      Re: Hmm - what if the lights are off....?

      As above: data transmission is achieved by modulating the light levels very quickly (rather than simple on/off). It can therefore operate in very low light levels (invisible to the human eye) - albeit with a bandwidth penalty - which would allow the system would operate in a “dark” building.

  15. Loyal Commenter

    I can think of several issues

    Presumably not all insurmountable, but off the top of my head:

    Limited by line-of sight (or reflection)

    No interference from EM radiation? What about the fact that light is EM radiation? Will receivers be 'blinded' by oversaturation from things like camera flashes, lightning strikes, or other rapid changes in ambient light levels? What about moths and other flying insects?

    Eavesdropping - better have your blackout blinds and curtains shut if you don't want your neighbours across the street eavesdropping (okay, I know this is no worse than Wi-Fi, but still...)

    Backhaul? How will this work? Will it need special light sockets with wired network, or will it use Wi-Fi for backhaul? If Wi-Fi, what is the point - you're already using the Wi-Fi bandwidth, so why not use Wi-Fi directly? If wired, then will I need to rip all the wiring out from my lighting circuit and replace it? You could use IP over powerline, but that is pretty useless when lighting is on a separate circuit to your power sockets (with a breaker that has a different current limit).

    What is the expected lifespan of one of these special bulbs? I know LED bulbs last a lot longer than incandescent ones, but I'm willing to bet they'll still burn out - either the LEDs or the control circuitry.

    1. Zack Mollusc

      Simple fix

      The line of sight and interference problems are trivial to fix. Simply run fibre optics from the light bulb to the client device.

    2. Balding Greybeard

      Re: I can think of several issues

      @Loyal Commenter, you got to give power over Ethernet another try. I have 4-Netgear Powerline 2000s, Ethernet over power devices. Brings Ethernet to all 3-levels of my townhouse. And even use it to Connect my 3-node Google WiFi nodes. Google WiFi initially barked about the speed, but once settled in, I have consistent throughput to my wireless and streaming wired Hulu devices. No interference from neighbors, no glitchy performance. I walk around the house with iPad in-hand seamlessly transitioning from Google node to Google node.

  16. Nick Kew


    failed to capture the imagination of the public.

    But don't we all love the Clacks?

  17. Kubla Cant


    Do we add this to the list of things that become useless in bright sunshine? (TVs, monitors, smartphones, the digital speedo in my car...)

  18. RayG

    I don't know about anyone else, but I'm hearing "Nobody adopted this tech because it didn't really fill a need well enough for people to get over the practical hurdles, so let's throw more money at it".

    1. maffski

      Research farming in the EU

      It's taxpayers money. Specifically 5.9 million euros of taxpayers money.

      '...Main project goals are to provide an open reference architecture for the support of IoT in the lighting infrastructure, build consensus reflecting the best architectural choices, contribute to standardization of lighting and telecom infrastructures in IEC, IETF, IEEE and ITU-T and provide a roadmap for IoT until 2022 and beyond...'

      5.9m euros to attend some conferences, draw up a powerpoint and write a spec. no one will ever use.

      To quote Milton Friedman 'I’m sure going to have a good lunch!'

      1. Loyal Commenter

        Re: Research farming in the EU

        To be fair, if you want people to draw up decent standards for things, you have to pay them in more than magic beans, and if you want a reference architecture, then you're going to need hardware prototypes, and such things don't come cheap.

        The whole point of innovation is that sometimes it goes nowhere. That money isn't wasted though, because lessons are learned, knowledge is gained, and the dead-ends are made up for by the other things that do go somewhere. It's pretty much the definition of research - if you already knew what the result would be, it wouldn't be research...

        1. RayG

          Re: Research farming in the EU

          I agree research is speculative and has to accept funding some things that turn out to be dead ends... so there's a good case for writing off the cost of the previous round of work on this subject. Throwing more after it isn't really taking a risk for a chance of innovation, it's safely progressing something we already know isn't a bright idea. Seems like it could be an example of the sunk cost fallacy - a favoured choice of dim bulbs.

          1. Loyal Commenter

            Re: Research farming in the EU

            I suppose it all comes down to whether you can find a convincing use case for it that isn't already covered by other technologies (e.g. Wi-Fi, or a length of good ol' fashioned CAT6e). I'm struggling to think of one, possibly some environments where you need to keep the RF noise really low, or you don't want signals leaking through walls (but don't want wires, or a faraday cage). It's certainly goig to be niche, but might find military or covert uses.

  19. Anonymous Coward
    Anonymous Coward

    Help, help, I'm being irradiated!

    How long before it's "discovered" that this causes migraines/headaches/allergies and other compo attracting disorders?

    1. jonathan keith

      Re: Help, help, I'm being irradiated!

      How about a nasty sunburn?

    2. Ugotta B. Kiddingme

      Re: Help, help, I'm being irradiated!

      "Come and see the violence inherent in the system! light!"

  20. mark l 2 Silver badge

    I am really struggling to think of many practical uses for LiFi other than the very limited use in environments where you can't use WiFi or Ethernet. As LiFi will be restricted to individual rooms since it relies on line of sight it is less practical than WiFi so can't be used for mobile devices without drop outs when you move from one room to the next. And even for static devices which never move your going to need to ensure that you maintain consistent line of sight with nothing blocks the sensors.

  21. UberMunchkin

    I expect the biggest roadblock for adoption is that a lot of us techies will see the 'Internet of Things' part of the statement and immediately file them under "Garbage ideas for garbage technology". The IoT is a mess of unsecured and poorly thought out rubbish that anyone with half a brain will avoid for a long time.

  22. Anonymous Coward
    Anonymous Coward

    (singing tunelessly to self, spray cans in pinny pockets and duster in hand)

    "Don't mind me, deary," (sprays desk, wipes)," just freshening the place up" (sprays lemon-scented air-freshener)

    "My! Them's some fruity words you know, there, dear! What's gone wrong with your internet, then?" (sprays desktop computer, polishes..)

  23. Zebo-the-Fat


    I'm in the dark about this!

  24. Richard 51

    Old technology given a new lease

    My father worked on this technology in the 70's at STC (a defunct telecoms company). Light is electromagnetic radiation, just much higher frequency so to say there is less electromagnetic interference is plain wrong. The reason they dropped it was primarily that the amount of light pollution meant the noise levels were problematic and its of course line of sight, if people walk in front of the transmitter the signal can be lost. But I guess the frequency and modulation in todays implementation will mean these problems are less of a concern.

  25. Uplink

    One way?

    OK, so you use lights to transmit data to the devices, which presumably will get quite of bit of the data through reflections. How do the devices send the data back to the light fixture? Signal shadows/eclipses are a lot more likely when you're hunched over your laptop.

    I have this feeling we'll get a "dongle" that sticks out so it can see the light bulb.

    1. Zebo-the-Fat

      Re: One way?

      Don't let your dongle dangle!

  26. LeahroyNake

    Close the curtains

    I suppose closing your curtains is much easier than getting WiFi security configured correctly, even if most home WIFI boxes are (or should be) secure by default.

    Does anyone else remember having to use irda (or whatever its called, think back to when Nokia was the phone to have) to connect a mobile to their laptop.... Lots of fun that was lol

  27. electricmonk


    "The idea is simple: make the light flicker faster than the eye can see, delivering a stream of 1s and 0s that can be picked up by a nearby photodetector USED TO CONTROL THE MINDS OF THE POPULACE!!!!!111!!"


    Pass me my tinfoil sunglasses , would you?

  28. Jamie Jones Silver badge

    Elephant in the room..

    Um... Daytime?

    Do we have to keep our lights on during the day? Even worse, do we have to close all the curtains?

    Will street lights be on all day? Will street-light li-fi work at noon on a sunny day?

  29. Ittopgun

    Bumpe r

    I worked on line of sight transmission in the mid 60s where we ued a low powered laser as the carrier. With fibre optics now this could make a very useful secure way of transmitting large chunks of data without the fear of anyone listening in? Not a good idea as a substitute for WiFi but could have a future for short range Comms or long range secure fibre optic transmission?

  30. gnarlymarley

    Li-Fi might work great in England, but not so much in the USA. England has the cloudy thing going on. In the USA, there is much sunlight (which makes solar panels a better option) that leaks through the windows. A lot of people use the windows instead of a light bulb. It would work great at night, but not so much during the daytime.

  31. Henry Wertz 1 Gold badge

    how is it connected?

    For me the reason for not using this is more practical... I don't have ethernet ports in my light sockets. And if I used ethernet over powerline (homeplug or the like), the speed of that is lower than 802.11ac anyway.

    There are those hotels where they'll like hide an access point (and phone jack and ethernet jack) in a table lamp. Lifi would be easy to add in these cases 8-)

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