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Li-Fi

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Not to be confused with Wi-Fi, Hi-Fi, or Lo-Fi.

Li-Fi Technology
IntroducedMarch 2011; 14 years ago (2011-03)
IndustryDigital communication
Connector typeVisible light communication
Physical rangevisible light spectrum, ultraviolet and infrared radiation

Li-Fi (commonly referred to as LiFi) is a wireless communication technology which utilizes light to transmit data and position between devices. The term was first introduced by Harald Haas during a 2011 TEDGlobal talk in Edinburgh.[1]

Li-Fi is a light communication system that is capable of transmitting data at high speeds over the visible light, ultraviolet, and infrared spectrums.

In terms of its end user, the technology is similar to Wi-Fi – the key technical difference being that Wi-Fi uses radio frequency to induce an electric tension in an antenna to transmit data, whereas Li-Fi uses the modulation of light intensity to transmit data. Li-Fi is able to function in areas otherwise susceptible to electromagnetic interference (e.g. aircraft cabins, hospitals, or military applications).[2][3]

Technology details

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Li-Fi modules

Li-Fi is a derivative of optical wireless communications (OWC) technology, which uses light from light-emitting diodes (LEDs) as a medium to deliver network, mobile, high-speed communication in a similar manner to Wi-Fi.[4] Projections of the LiFi market varies greatly between analysts. They range from a compound annual growth rate (CAGR) of 17% to 63% from 2023 to 2030 and projections suggest it will grow to between $10.9 billion and $116.96 billion by 2030.[5] [6]

Visible light communications (VLC) works by switching the current to the LEDs off and on at a very high speed, beyond the human eye's ability to notice.[7] Technologies that allow roaming between various Li-Fi access points, also known as handover, may allow seamless transition between such access points. The light waves cannot penetrate walls which translates to a much shorter range, and a lower hacking potential, relative to Wi-Fi.[8][9] Direct line of sight is not always necessary for Li-Fi to transmit a signal and light reflected off walls, mirrors or other reflective objects.

Li-Fi can potentially be useful in electromagnetic sensitive areas without causing electromagnetic interference.[10][9] [11]Both Wi-Fi and Li-Fi transmit data over the electromagnetic spectrum, but whereas Wi-Fi utilizes radio waves, Li-Fi uses visible, ultraviolet, and infrared light.[12] Researchers have reached data rates of over 224 Gbit/s.[13] Li-Fi was expected to be ten times cheaper than Wi-Fi.[14] While several Companies produce Li-Fi products such as PureLiFi[15], Signify[16], Oledcomm[17], Terra Ferma[18] and others; Wi-Fi and cellular remain the predominant communications technology for consumers, business, industrial and military applications. The first commercially available Li-Fi system was presented at the 2014 Mobile World Congress in Barcelona.

Disadvantages

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Although Li-Fi LEDs would have to be kept on to transmit data, they could be dimmed to below human visibility while still emitting enough light to carry data.[14] This is also a major bottleneck of the technology when based on the visible spectrum, as it is restricted to the illumination purpose and not ideally adjusted to a mobile communication purpose, given that other sources of light, for example the sun, will interfere with the signal.[19] Most products available today use the near IR (NIR) spectrum, specifically between 780 nm and 2500 nm, is a crucial part of LiFi technology, offering a large bandwidth for high-speed data transfer.

Since Li-Fi's short wave range is unable to penetrate walls, transmitters would need to be installed in every room of a building to ensure even Li-Fi distribution. The high installation costs associated with this requirement to achieve a level of practicality of the technology is one of the potential downsides.[7][20][21]

History

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The initial research on Visible Light Communication (VLC) was published by the Fraunhofer Institute for Telecommunications in September 2009, showcasing data rates of 125 Mbit/s over a 5 m distance using a standard white LED.[22] In 2010, transmission rates were already increased to 513 Mbit/s using the DMT modulation format.[23]

During his 2011 TED Global Talk, Professor Harald Haas, a Mobile Communications expert at the University of Edinburgh, introduced the term "Li-Fi" while discussing the concept of "wireless data from every light".[24]

The general term "visible light communication" (VLC), whose history dates back to the 1880s, includes any use of the visible light portion of the electromagnetic spectrum to transmit information. The D-Light project, funded from January 2010 to January 2012 at Edinburgh's Institute for Digital Communications, was instrumental in advancing this technology, with Haas also contributing to the establishment of a company for its commercialization.[25][26]

In October 2011, the Fraunhofer IPMS research organization and industry partners formed the Li-Fi Consortium, to promote high-speed optical wireless systems and to overcome the limited amount of radio-based wireless spectrum available by exploiting a completely different part of the electromagnetic spectrum.[27]

The practical demonstration of VLC technology using Li-Fi[28] took place in 2012, with transmission rates exceeding 1 Gbit/s achieved under laboratory conditions.[29] In 2013, laboratory tests achieved speed of up to 10 Gbit/s. By August 2013, data rates of approximately 1.6 Gbit/s were demonstrated over a single color LED.[30] A significant milestone was reached in September 2013 when it was stated that Li-Fi, or VLC systems in general, did not absolutely require line-of-sight conditions.[31] In October 2013, it was reported Chinese manufacturers were working on Li-Fi development kits.[32]

In April 2014, the Russian company Stins Coman announced the BeamCaster Li-Fi wireless local network, capable of data transfer speeds up to 1.25 gigabytes per second (GB/s). They foresee boosting speeds up to 5 GB/s in the near future.[33] In the same year, Sisoft, a Mexican company, set a new record by transferring data at speeds of up to 10 GB/s across a light spectrum emitted by LED lamps.[34]

Current offerings by purelifi, Signify, oledcomm and Terra Ferma suggest Li-Fi full-duplex communications links can achieve over 1.0Gbps. A study published by IEEE in 2021 suggests speeds of 224 Gbps are achievable.[35]

In June 2018, Li-Fi successfully underwent testing at a BMW plant in Munich for industrial applications under the auspices of the Fraunhofer Heinrich-Hertz-Institute.[36]

In August 2018, Kyle Academy in Scotland, piloted the usage within its premises, enabling students to receive data through rapid on–off transitions of room lighting.[37]

In June 2019, Oledcomm, a French company, showcased its Li-Fi technology at the 2019 Paris Air Show.[38]

In January 2025, Terra Ferma, a USA company announced the launch of their Helios and Fortis Li-Fi product lines for US and NATO Government and Military applications.

Standards

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Li-Fi is a wireless technology, similar to Wi-Fi, but instead of using radio waves, it uses light (like regular room lights or infrared) to send information. Think of it like high-speed Morse code using flickering light!

The Rules of Li-Fi: ITU G.9991 (G.vlc)

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This is one of the first official "rulebooks" for Li-Fi, created in 2019. Here’s what makes it special:

  • Smart Light Communication: It uses regular LED lights (the kind in your home) and infrared to send data. The system automatically adjusts to different lighting conditions, like dim rooms or bright sunlight[39][40].
  • Super Fast Speeds: With G.vlc, Li-Fi can reach speeds up to 250 Mbps for downloads and 200 Mbps for uploads—fast enough to stream 4K movies[41].
  • No Interference: Unlike Wi-Fi, Li-Fi’s light signals don’t interfere with each other. You can use the same light spectrum in every room without slowdowns.
  • Works With Existing Tech: G.vlc uses chipsets from home internet systems (like powerline networks), making it easier and cheaper for companies to build Li-Fi products[42].
  • Supports Many Devices: One Li-Fi light can connect up to 16 devices at once, like phones, laptops, or smart home gadgets.

How Does G.vlc Work?

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  • Efficient Data Splitting: It uses a method called OFDM (like splitting data into multiple mini-streams) to avoid "traffic jams" and work even if some light signals get blocked.
  • Two Modes for Different Needs:[43]
    • DCO-OFDM: For max speed (up to 1.7 Gbps in perfect conditions).
    • ACO-OFDM: Slower but works in very dim lighting.
  • Security Bonus: Light can’t go through walls, so your Li-Fi connection stays private within the room.

Real-World Uses

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Companies like Signify (which makes Philips lights) already use G.vlc in products like Trulifi, which lets offices, hospitals, and factories get internet from their ceiling lights45. Researchers are also adding cool features like:

  • Motion Tracking: Using Li-Fi to locate devices in a room.
  • Low-Power Mode: For smart sensors that need tiny amounts of energy.

Why Standards Matter

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Just like Wi-Fi needs rules to work everywhere, Li-Fi standards like G.vlc and IEEE 802.11bb (another newer standard) ensure all Li-Fi devices can "talk" to each other. This helps Li-Fi grow from labs to your living room![44]

802.11bb

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Main article: IEEE 802.11bb

In July 2023, the IEEE published the 802.11bb standard for light-based networking, intended to provide a vendor-neutral standard for the Li-Fi market.

Potential applications

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Home and building automation

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Many experts foresee a movement towards Li-Fi in homes because it has the potential for faster speeds and its security benefits with how the technology works. Because the light sends the data, the network can be contained in a single physical room or building reducing the possibility of a remote network attack. Though this has more implications in enterprise and other sectors, home usage may be pushed forward with the rise of home automation that requires large volumes of data to be transferred through the local network.[45]

Underwater application

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Most remotely operated underwater vehicles (ROVs) are controlled by wired connections. The length of their cabling places a hard limit on their operational range, and other potential factors such as the cable's weight and fragility may be restrictive. Since light can travel through water, Li-Fi based communications could offer much greater mobility.[46][unreliable source] Li-Fi's utility is limited by the distance light can penetrate water. Significant amounts of light do not penetrate further than 200 meters. Past 1000 meters, no light penetrates.[47]

Aviation

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Efficient communication of data is possible in airborne environments such as a commercial passenger aircraft utilizing Li-Fi. Using this light-based data transmission will not interfere with equipment on the aircraft that relies on radio waves such as its radar lifi connectivity.[48]

Hospital

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Increasingly, medical facilities are using remote examinations and even procedures. Li-Fi systems could offer a better system to transmit low latency, high volume data across networks.[citation needed] Besides providing a higher speed, light waves also have reduced effects on medical instruments. An example of this would be the possibility of wireless devices being used in MRIs similar radio sensitive procedures.[48] Another application of LiFi in hospitals is localisation of assets and personnel.[49]

Vehicles

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Vehicles could communicate with one another via front and back lights to increase road safety. Street lights and traffic signals could also provide information about current road situations.[50]

Outdoor Use

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Due to the specific properties of light, the optical beams can be bundled especially well in comparison to radio-based devices, allowing highly directional Li-Fi systems to be implemented. Devices have been developed for outdoor use that make it more difficult to access the data due to their low beam angle, thus increasing the security of the transmission. These can be used, for example, for building-to-building communication or for networking small radio cells.

Industrial automation

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Anywhere in industrial areas data has to be transmitted, Li-Fi is capable of replacing slip rings, sliding contacts, and short cables, such as Industrial Ethernet. Due to the real-time of Li-Fi (which is often required for automation processes), it is also an alternative to common industrial Wireless LAN standards. Fraunhofer IPMS, a research organization in Germany states that they have developed a component which is very appropriate for industrial applications with time-sensitive data transmission.[51]

Advertising

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Street lamps can be used to display advertisements for nearby businesses or attractions on cellular devices as an individual passes through. A customer walking into a store and passing through the store's front lights can show current sales and promotions on the customer's cellular device.[52]

Warehousing

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In warehousing, indoor positioning and navigation is a crucial element. 3D positioning helps robots to get a more detailed and realistic visual experience. Visible light from LED bulbs is used to send messages to the robots and other receivers and hence can be used to calculate the positioning of the objects.[53]

See also

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References

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  1. ^ Harald Haas (2 August 2011). "Harald Haas: Wireless data from every light bulb". ted.com. Archived from the original on 8 June 2017.
  2. ^ Tsonev, Dobroslav; Videv, Stefan; Haas, Harald (18 December 2013). "Light fidelity (Li-Fi): towards all-optical networking". Proc. SPIE. Broadband Access Communication Technologies VIII. 9007 (2). Broadband Access Communication Technologies VIII: 900702. Bibcode:2013SPIE.9007E..02T. CiteSeerX 10.1.1.567.4505. doi:10.1117/12.2044649. S2CID 1576474.
  3. ^ "What is Li-Fi? Internet Access Through Light-Based Technology Explained". CNET. Retrieved 23 May 2025.
  4. ^ Sherman, Joshua (30 October 2013). "How LED Light Bulbs could replace Wi-Fi". Digital Trends. Archived from the original on 27 November 2015. Retrieved 29 November 2015.
  5. ^ "Light Fidelity (Li-Fi) Market to Hit $7,757.3 Million by 2030: Grand View Research, Inc". www.prnewswire.com. 9 March 2023. Retrieved 23 May 2025.
  6. ^ "North American Li-Fi market set to reach $2.5 billion by 2030 | Electro Optics". www.electrooptics.com. Retrieved 23 May 2025.
  7. ^ a b Coetzee, Jacques (13 January 2013). "LiFi beats Wi-Fi with 1Gb wireless speeds over pulsing LEDs". Gearburn. Archived from the original on 5 December 2015. Retrieved 29 November 2015.
  8. ^ Li-Fi – Internet at the Speed of Light, by Ian Lim, the gadgeteer, dated 29 August 2011 Archived 1 February 2012 at the Wayback Machine
  9. ^ a b "Visible-light communication: Tripping the light fantastic: A fast and cheap optical version of Wi-Fi is coming". The Economist. 28 January 2012. Archived from the original on 21 October 2013. Retrieved 9 March 2021.
  10. ^ "Li-Fi: A green avatar of Wi-Fi". Mint. 9 January 2016. Archived from the original on 25 February 2016. Retrieved 24 February 2016.
  11. ^ "Explorez la technologie LiFi : LiFi Blogs". Oledcomm. Retrieved 23 May 2025.
  12. ^ Haas, Harald (19 April 2013). "High-speed wireless networking using visible light". SPIE Newsroom. doi:10.1117/2.1201304.004773. S2CID 54687970.
  13. ^ "LiFi internet breakthrough: 224Gbps connection broadcast with an LED bulb". 16 February 2015.
  14. ^ a b Condliffe, Jamie (28 July 2011). "Will Li-Fi be the new Wi-Fi?". New Scientist. Archived from the original on 31 May 2015.
  15. ^ pureLiFi. "Our Solutions | pureLiFi Solutions | LiFi Systems | LiFi Components". pureLiFi. Retrieved 23 May 2025.
  16. ^ "Get high-speed Internet anywhere you have lights with LiFi". Signify. Retrieved 23 May 2025.
  17. ^ "LiFi Technology by Oledcomm: High-Speed Internet Solutions". Oledcomm. Retrieved 23 May 2025.
  18. ^ "Home". Terra Ferma. Retrieved 23 May 2025.
  19. ^ "What are the advantages and disadvantages of Li-Fi technolog". Techopedia.com. 6 July 2020. Retrieved 14 June 2022.
  20. ^ Stephanie (2 December 2015). "Why Li-Fi Won't Replace Your Wi-Fi Router Any Time Soon". Retrieved 14 June 2022.
  21. ^ Mas-Machuca, Carmen; Kaufmann, Madeleine; Riegel, Maximilian; Schulz, Dominic; Stobbelaar, Pieter; Müller, Marcel; Behnke, Daniel (October 2022). "Techno-Economics of LiFi compared to Wi-Fi in Industrial IoT applications". IECON 2022 – 48th Annual Conference of the IEEE Industrial Electronics Society: 1–5. doi:10.1109/IECON49645.2022.9968851.
  22. ^ "125 Mbit/s over 5 m wireless distance by use of OOK-Modulated phosphorescent white LEDs". IEEE Xplore: 1–2. 20 September 2009. Retrieved 11 September 2024.
  23. ^ Vucic, Jelena; Kottke, Christoph; Nerreter, Stefan; Langer, Klaus-Dieter; Walewski, Joachim W. (25 October 2010). "513 Mbit/s Visible Light Communications Link Based on DMT-Modulation of a White LED". Journal of Lightwave Technology. 28 (24): 3512. Bibcode:2010JLwT...28.3512V. doi:10.1109/JLT.2010.2089602. Retrieved 11 September 2024.
  24. ^ "Wireless data from every light bulb". 2 August 2011. Archived from the original on 2 February 2016. Retrieved 2 February 2016.
  25. ^ Povey, Gordon. "About Visible Light Communications". pureVLC. Archived from the original on 18 August 2013. Retrieved 22 October 2013.
  26. ^ Haas, Harald (July 2011). "Wireless data from every light bulb". TED Global. Edinburgh, Scotland. Archived from the original on 8 June 2017.
  27. ^ Povey, Gordon (19 October 2011). "Li-Fi Consortium is Launched". D-Light Project. Archived from the original on 18 August 2013. Retrieved 22 October 2013.
  28. ^ Watts, Michael (31 January 2012). "Meet Li-Fi, the LED-based alternative to household Wi-Fi". Wired Magazine. Archived from the original on 25 May 2016.
  29. ^ Kottke, Christoph (16 September 2012). "1.25 Gbit/s visible light WDM link based on DMT modulation of a single RGB LED luminary". IEEE Xplore. pp. We.3.B.4. doi:10.1364/ECEOC.2012.We.3.B.4. ISBN 978-1-55752-950-3.
  30. ^ pureVLC (6 August 2012). "pureVLC Demonstrates Li-Fi Streaming along with Research Supporting World's Fastest Li-Fi Speeds up to 6 Gbit/s". Press release. Edinburgh. Archived from the original on 23 October 2013. Retrieved 22 October 2013.
  31. ^ purelifi.com (10 September 2013). "pureVLC Demonstrates Li-Fi Using Reflected Light". Edinburgh. Archived from the original on 29 June 2016. Retrieved 17 June 2016.
  32. ^ Thomson, Iain (18 October 2013). "Forget Wi-Fi, boffins get 150Mbps Li-Fi connection from lightbulbs: Many (Chinese) hands make light work". The Register. Archived from the original on 22 October 2013. Retrieved 22 October 2013.
  33. ^ "Li-Fi internet solution from Russian company attracting foreign clients". July 2014.
  34. ^ Vega, Anna (14 July 2014). "Li-fi record data transmission of 10GBps set using LED lights". Engineering and Technology Magazine. Archived from the original on 25 November 2015. Retrieved 29 November 2015.
  35. ^ Europe, eeNews (18 February 2015). "Li-Fi achieves 224-Gbps data transmission speeds with room-scale coverage". eeNews Europe. Retrieved 23 May 2025.
  36. ^ "Li-Fi passes industrial test with BMW's robotic tools". eeNews Europe. 15 June 2018. Retrieved 24 June 2019.
  37. ^ Peakin, Will (28 August 2018). "Kyle Academy first school in world using light to create wireless networks". FutureScot. Retrieved 30 June 2019.
  38. ^ "High-speed LiFi will soon be available on Air France flights". Engadget. 12 June 2019. Retrieved 30 June 2019.
  39. ^ "ITU-T G.9991". www.hhi.fraunhofer.de. Retrieved 23 May 2025.
  40. ^ Eggmayr, Bernadette (1 January 2020). "ITU-T G.9991 (aka G.VLC) Activities in 2020". ELIoT. Retrieved 23 May 2025.
  41. ^ "Li-Fi and Other Visible Light Communications (VLC) Standards". www.connectivity.technology. Retrieved 23 May 2025.
  42. ^ "On Standardisation of LiFi and Beyond - Li-Fi Conference 2023 Presentation". LiFi Tech News Upgrade. Retrieved 23 May 2025.
  43. ^ Eggmayr, Bernadette (1 January 2020). "ITU-T G.9991 (aka G.VLC) Activities in 2020". ELIoT. Retrieved 23 May 2025.
  44. ^ "On Standardisation of LiFi and Beyond - Li-Fi Conference 2023 Presentation". LiFi Tech News Upgrade. Retrieved 23 May 2025.
  45. ^ "LiFi Technology". pureLiFi. Retrieved 16 April 2021.
  46. ^ "Li – Fi Technology, Implementations and Applications" (PDF). International Research Journal of Engineering and Technology. Archived (PDF) from the original on 17 November 2016.
  47. ^ "How far does light travel in the ocean?". Archived from the original on 31 January 2017. Retrieved 4 February 2017.
  48. ^ a b Ayara, W. A.; Usikalu, M. R.; Akinyemi, M. L.; Adagunodo, T. A.; Oyeyemi, K. D. (July 2018). "Review on Li-Fi: an advancement in wireless network communication with the application of solar power". IOP Conference Series: Earth and Environmental Science. 173 (1): 012016. Bibcode:2018E&ES..173a2016A. doi:10.1088/1755-1315/173/1/012016. ISSN 1755-1315.
  49. ^ "Ellipz LiFi medical – real time indoor positioning (RTLS) with LiFi". medicallifi.io. Archived from the original on 24 December 2021. Retrieved 24 December 2021.
  50. ^ "Applications of Li-Fi – pureLiFi™". pureLiFi. Archived from the original on 20 November 2016. Retrieved 15 November 2016.
  51. ^ Happich, Julien. "Fraunhofer IPMS pushes Li-Fi to 12.5Gbit/s for industrial use". European Business Press SA. André Rousselot. Retrieved 13 November 2017.
  52. ^ Swami, Nitin Vijaykumar; Sirsat, Narayan Balaji; Holambe, Prabhakar Ramesh (2017). Light Fidelity (Li-Fi): In Mobile Communication and Ubiquitous Computing Applications. Springer Singapore. ISBN 978-981-10-2630-0.
  53. ^ "5 Essential Technologies for Inventory Control in a Warehouse Contract". publication.sipmm.edu.sg. 16 April 2019. Retrieved 8 April 2022.
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