Edited by Kimberley Chee.
“LiFi” is a term first coined by Professor Harald Haas¹ in a talk in Edinburgh, and it is defined as wireless communication technology that uses infrared and visible light spectrums for high speed data communication. It is an extension of the concept of visible light communication (VLC). However, unlike VLC, which uses unidirectional, point-to-point light communication at low data rates, LiFi technology is fully networked, bidirectional, and wirelessly high-speed.²
LiFi is known to have a higher speed of data transmission than the currently used WiFi. Its speed is greater than 1Gbps, making it about 100 times faster than WiFi, which typically has an optimum speed of around 150Mbps. Unfortunately, the speed of WiFi is a lot less than 150Mbps practically, enhancing the superiority of LiFi over WiFi in terms of speed.³
This makes LiFi a very attractive option for downloading movies, games and music that contain huge files. The main reason for the high speed of LiFi is that its bandwidth is 10,000 times greater than radio waves, for which spectrum is often in short supply. Therefore, this limited bandwidth makes interference between radio waves significantly more likely compared to visible light, which travels at many different frequencies, limiting their chances of undergoing superposition.⁴
Internet connection is produced by the variations of brightness of the LED light bulbs. The variations are caused by the changes in currents, allowing binary values of 0 and 1 to be produced. If the light bulb is turned on, the digital value produced would be 1; if the light bulb is turned off, the digital value produced would be 0. LED light bulbs are specifically chosen due to their ability to be turned on and off quickly, allowing them to transmit data in the form of light. However, the LED light bulbs must be attached to a downlink transmitter, which links the satellites to a Li-Fi network. The system is equipped with a receiver dongle which converts tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or any mobile device.⁵
Attracted by the prospect of not needing to build costly telecommunication towers to provide internet connection, there have been many proposals to improve internet availability in rural areas through Li-Fi technology. One such proposal was made by Akram, who discussed the potential of Li-Fi technology to improve internet availability in rural India.⁶ Many Indian households have a light bulb, and it would significantly reduce the effort needed to provide them with internet connection. Although the installation fees are a one-off investment, the initial costs are hefty. Furthermore, solar cells are not a reliable source of electricity on non-sunny days, causing rural Indians to be cut off from the internet during these times.
The biggest problem with Li-Fi, however, is the lack of compatible devices. In fact, the only company to have launched a Li-Fi enabled smartphone is Oppo.⁷ Hence, implementing Li-Fi on a large scale might be challenging.
Moreover, devices need to be connected to a receiver dongle to receive signals. However, many modifications to the traditional Li-Fi technology have been suggested. Professor Harald Haas⁸ claims that solar panels can be used as receivers for Li-Fi. Since many parts of India lack electricity, Akram suggested the use of Li-Fi enabled solar panels⁶, which can convert data to electrical signals, allowing people to connect to the Internet even without access to national electricity. Nevertheless , the main concern with Li-Fi usage in rural India is still the high cost of installation, but this modification to Li-Fi technology might make them more viable as a common source of internet connection in the future.
Needless to say, Li-Fi is a hugely foreign technology that is worth exploring. It can bring internet speeds to a whole different level, and potentially help us take a big step forward in achieving reliable, accessible and universal internet connection.
References:
Hass, H. (2011, July). Wireless data from every light bulb. In TEDGlobal 2011 [Video]. TED. https://www.ted.com/talks/harald_haas_wireless_data_from_every_light_bulb
Hass, H. (2017, October 27). LiFi is a paradigm-shifting 5G technology. Reviews in Physics, 3(November 2018), 26 - 31. https://www.sciencedirect.com/science/article/pii/S2405428317300151
'Li-fi 100 times faster than wi-fi'. (2015, November 27). BBC. https://www.bbc.com/news/technology-34942685
Sharma, R., Raunak, & Sanganal, A. (2013). Li-Fi Technology Transmission of data through light.
Poonam, P. V., & Siddiqui, S. (2014). Li-Fi Technology. INTERNATIONAL JOURNAL OF COMPUTER SCIENCE AND INFORMATION TECHNOLOGIES. http://ijcsit.com/docs/Volume%205/vol5issue06/ijcsit20140506250.pdf
W.Akram, (2019). Potential of Li-Fi (Light Fidelity) Technology for Internet Penetration in Rural India. International Journal of Computer Sciences and Engineering, 7(1), 684-689.
Oppo to launch a Li-Fi compatible smartphone. (2020, August 18). Malay Mail. https://www.malaymail.com/news/tech-gadgets/2020/08/18/oppo-to-launch-a-li-fi-compatible-smartphone/1894811
Hass, H. (2015, September). Forget Wi-Fi. Meet the new Li-Fi Internet [Video]. TED. https://www.ted.com/talks/harald_haas_forget_wi_fi_meet_the_new_li_fi_internet?language=en