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Lifi title

The age of WiFi connectivity may become part of history sooner than we thought, after scientists finally put the light based communication format “Li-Fi” into practice.

Recent tests by engineers in Tallinn, Estonia reported they can achieve data transmission at a whopping 1 GB per second- over 100 times faster than current average WiFi speed.

To put that in perspective, at those speeds, you could download a high-definition movie in literally a few seconds.

The test were done in offices and industrial environments in the Estonian capital after years of devolvement by a tech start-up called Velmenni.

So What is Li-Fi?

Li-Fi makes use of light waves instead of radio technology to deliver data, the resulting connection delivers up to 224 gigabits per second.

Li-Fi technology uses Visible Light Communication (VLC), a format that harnesses visible light between 400 and 800 terahertz (THz). The format could be compared to a, very advanced, form of Morse code, like switching a torch on and off to relay a message. However, in this case flicking an LED on and off at extreme speeds can allow binary code to be transmitted.

LiFi demonstration imageImage sciencealert.com


Back in February this year, researchers at Oxford University were working on developing the Li-Fi technology but were running into issues when it came to linking solid signal to a device.

Unlike WiFi which transmits via radio waves, Li-Fi relies on light. Although light is already used to transmit data across fibre optic networks at high speed (fibre broadband), these signals are easily corralled and guided along optical fibres using total internal reflection, so that no information is lost along the way.

However, transmitting information by beaming light through the air is far more difficult, because there is no enclosed ‘light tunnel’ to guide the signal to where it needs to go. Like watering plants via a sprinkler in the room, rather than a hose direct to the pot.


Why move over to the light?Lifi room diagram

Well, apart from the obvious speed benefits of Li-Fi, transferring data over light has a few more handy fea  tures.

First is bandwidth, or space technically… The visible light spectrum is plentiful, free and unlicensed, meaning that unlike the costly and rapidly filling radio frequency spectrum, it’s open to new use.

Second usage, light can be used where radio waves can’t like aircraft cabins, hospitals and radio sensitive environments.

Third, LiFi could be used in conjunction with traditional light meaning, your lightbulb at home could become a wireless outlet for your internet connection. PureLiFi, a start-up from Edinburgh was the first to offer a light bulb fitting capable of acting as the equivalent of a wireless network in the home.

Fourth is Efficiency, Li-Fi is literally data via illumination. If you’re already using bulbs to provide light adding data to the at equation means you’re investing in the extra energy costs.

And finally security, since light doesn’t penetrate walls, transferred data is technically more secure due to it only being accessible to users in the same room.



Ok so LiFi seems pretty impressive, but what about the drawbacks?

Well there are few, the major being we are currently in the development stage of LiFi so it’s unlikely to be in your home anytime in the near future.

Another issue is with light itself, although an advantage for security, as light cannot pass through walls, it’s a disadvantage for practicality.  You’ll need to have all the rooms in a building kitted out with LiFi distributors if you want full coverage like WiFi.

Light pollution could also prove to be an issue with LiFi with other light sources interfering with the signal, this could also be the same for outdoor connectivity.



It’s possible the future may have to see a hybrid between the two types of wireless coverage (or another) so that there are less blind spots when it comes to connectivity.

In a similar way your phone flicks between 2G to 4G when traveling, your WiFi could theoretically adapt depending on its surroundings.




  1. Li-Fi sounds good in theory, but your explanation is missing one important factor, LED = Light Emitting Diode – this means a downstream only (Emitting). It would also need all items to be within a “peripheral vision” or it would either drop the downstream completely or lower the overall speed.

    Surely, any current LED lighting would need to be changed, these are not cheap, but provide a long lifetime of economic ways of lighting. Diodes can come in various types these days, by using reverse voltages, or even a third connection – but in every case it “Emits” light, it does not receive, so this brings in the question, where would the “upstream” come from?

    Our street lights already use the latest LED lighting, they are okay at night but the light emitted is much lower than the previous “orange” glow from towns, which can be seen for miles away with the naked eye. If this technology was to go public in streets, it would require some heavy type of encryption or somehow to use the MAC address of the device.

    Your VLC example image has one issue, every item must be in range of LED light source, a typical household does not have layouts like an office. Some people have main desktop computer towers, printers, scanners, etc inside desks – these would be in blind-spots and the same would apply to gaming consoles.

    Another issue I would put to the developers is it would need a “Wake upon LAN”, present technology uses far too much electric over the year, I am referring to routers – they produce the highest stand-by consumption of electric, and we are supposed to be going green!

    The theory looks good but there are many flaws in what has been explained in your article. But like you said it is only in a development stage, but would be very economical to run.

  2. Read projects for doing this in practical electronics in the early 70’s using incandescent line of sight emitters

  3. Has anyone else noticed how the LiFi transmitted message in the first image reads “666” is that an ominous point of view???

  4. People appear to be concerned with security, why?
    Are you concerned about radio waves too? As it says above radio waves is how wifi is transmitted currently, and I dont have any issues with security on that.
    I assume that lifi will use light waves invisible to the naked eye, so you’re not seeing a constantly flickering light, in which case it could be two way communication and not one way as someone commented above (only you’ll need a light transmitter to send the signal.

  5. So there are a more than a few issues here:
    1) There’s a lightswitch in your picture, yay lets give the cleaner access to turn off our network!
    2) There’s a strange woman with a PDA next to her ear, what’s that about?

    On a more serious note, as a medium lighting has many flaws, there will be sweetspots and deadspots, depending on where your desk is located in an office.
    I generally have to replace bulbs a LOT more frequently than WiFi Routers.
    There is no mention of how data is returned back.Would we each need to have USB lamps pointing at another light source? Surely that would cause interference.
    Lights flicker, that would cause data corruption.

    From a Daily Mail article:
    Consumer group Which? tested 46 types of light bulb for endurance
    More than a quarter did not meet claims of a 15,000-hour life
    Disappointing result comes despite claims of them lasting 25,000 hours
    Some even fell below the legal minimum of 6,000 hours

    Read more: http://www.dailymail.co.uk/news/article-2546363/The-great-LED-lightbulb-rip-One-four-expensive-long-life-bulbs-doesnt-like-long-makers-claim.htm

    6000 hours is roughly 250 days, you can expect life span to be shorter if it’s consistently being asked to turn on and off.
    I would also be concerned about how this could affect people who suffer from conditions such as epilepsy.

  6. So, apart from getting data generated within the room to another point across the same room or building, and given the need to modify the wiring in order to get the lamps to transmit data, what is the advantage over a conventionally wired network? And given the need to do that, surely what you have is, in part, a copper based network- ie via the wiring to the lamp?

    @Anon re LED lamp life. One issue we have in the UK is that mains voltage is ‘harmonised’ with that of other countries in the EU- nominally 230 volts. However, whilst that may be so on paper, in actual fact the typical voltage is often somewhat higher as the grid infrastructure has not been altered. At my last house, I measured 256 volts- hardly surprising I was replacing bulbs with monotonous regularity.

  7. Modern LiFi is a new development of an old idea, so it is early days. The advantages over WiFi may not be apparent at the moment, but what you have to consider is that the RF spectrum is full, so in the future, there will be no option but to use light for data, unless more spectrum is made available. Using light will provide almost infinite bandwidth, but that is a long way off for current systems. Data density using light will be phenomenal. Because the frequency is so high relative to the channel bandwidth, you can pack in a huge number of channels at different frequencies. Current LiFi transmits data both directions. LiFi has many advantages over WiFi and some disadvantages. LiFi will not replace WiFi, but will work alongside WiFi for many years, but there will come a point when WiFi will run out of capacity. Remember modems?? they were brilliant for a while, but eventually could not provide the bandwidth when the internet took off big time.

  8. If you want to look to the future, look up Mark Weiser Xerox PARC on Wiki. He was a true visionary. Back in the late 80’s he coined the phrase ubiquitous computing, which has been reinvented as the ‘internet of things’ Weiser speculated that computers would eventually merge into the background, the age of calm technology. LiFi will be one of the technologies which will enable his vision.

  9. Could be good in an office environment. Where lights are installed above each desk this could give the user at the desk a reliable strong connection, and it can be exclusive too, i.e pairing your laptop / computer to the that particular light above your desk.

    So you have LIFI at your desk, but revert to WIFI when on the move in the office. For home’s and smaller environments, traditional WIFI will still be the best solution.

  10. Many users point out a good fact, How is data uploaded, is this only a 1 way communication method.

    If so, there would still be a good use of LIFI, here is a scenario.
    In my company, our CEO broadcasts all employee meetings once a quarter, this is a global company of around 200,000 employees, if everyone is watching it at their desk over the WIFI you will get buffering alot. So when a need arises to broadcast something they could use the LIFI in the building, which free’s up the the WIFI for other users.

  11. @Simon- Well spotted.
    How would LIFI affect human and animal health, there are creatures that see beyond the spectrum that we do, how would this affect aquarium fish in the same room? You would also possibly get refraction if the light passed through glass or the such.
    From a health point of view the old tube lights were detrimental to sleep patterns as they flickered at such a rate as to cause some people insomnia and other headaches, stress and so on.

  12. this article has so many flaws in it. Even the opening statement is incorrect – networks are measured in Bits per second so 1GBps would not download a Hi def movi in seconds also WiFi is already capable of running far higher than that now 802.11ac @ 3.4 Gbps. Please Danny Young get your facts straight before writing articles.

  13. @Steve – 1Gb is not 1GB, small b for bits big B for bytes. Lab connections of 224Gb could easily achieve 1GB in real world situations.

    @Ahmad – who cares about animals with different sight capabilities than humans regarding this technology, it uses visible light, that means we would be able to see it. However, if the lights were flickering on and off many thousands, if not millions or more, times a second I doubt it would be detectable by anything other than technology.

    As far as lifi goes, there is a long list of implementation issues to overcome before it would be practical, except in clearly defined roles. For example weaken wifi signals to reduce range and neighbouring interference and then use lifi for backhaul. This would enable more efficient use of radio spectrum and avoid many if the lifi implementation issues.

  14. Bit of a beggar when I use my laptop or tablet in my conservatory on a summer’s day or in a shady nook in the garden.

  15. LiFi is an obvious direction to go in. The big issues discussed here are security and the upstream pathway. While everyone is assuming that the light used for LiFi is the light used to illuminate the office, I am not at all sure that that is how it will work. My bet would be on putting an ir (infra-red) emitter/detector combo in the light fitting or into the ceiling. I don’t think that security is then a major issue. Provided end-to-end encryption is used, a simple ir attenuating film fitted over windows will provide sufficient additional security for most purposes as well as reducing any issue of sunlight interfering with the communications link. The uplink to the server can be either WiFi – with no downward traffic there should be no issue relating to capacity – or via an ir emitter in the user device linking to a detector in the LiFi access point. Both these solutions will probabably result in an asymetric connection but this is something that we have been coping with for years when using ADSL technology. The biggest issue to be wary of in a LiFi installation could well be shadows. However, since the LiFi access points could well be similar to the flush halogen light fittings built into very many ceilings today it should be easy to design shading out of the network.

  16. Old article now, 1gb sounds good but it was already an average of 15gb slower than 5g and in some cases 63gb slower. 5g is due for launch in the next 2-3 years as most trials are technically near completion with only licensing issues to deal with. 16gb is also the average mobile speed, tested while in transit speeds averaged by the leading 3 development companies.

  17. It’s a waste of time when limitations aren’t with the wifi, in more in over 95% of cases to do with the slow intermittent connections that come in to UK buildings from slow service providers!

  18. Are people who respond to these blogs half-witts? They seem to have no concept of reality and adoption of future technology! Go watch cats on Youtube unless you want to learn!!!!

  19. help me with detailed steps on how to create the lifi internet transmitter and lifi internet receiver and how to configure it to browse on the desktop(implementation at home)
    Help with videos and theoretical writs be it using the bread or pcb or empty circuit board

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