Move over Wi-Fi, say hello to Li-Fi
Wouldn’t it be amazing if the LED bulbs used in our homes were used as Wi-Fi hotspots to transmit data at high speeds? Well, It is actually viable with the invent of Li-Fi by German physicist Harald Hass from the university of Edinburgh, UK in 2012.
What is Li-Fi?
Light Fidelity (Li-Fi) is a cheap, duplex, high speed, wireless communication technology is analogous to Wi-Fi and is based on theory of VLC which is a subcategory of optical wireless communication. It boasts of high speed up to 224 gigabytes per second. It can be considered as an incredible complement of Wi-Fi and a substitution in terms of Data Broadcasting by some forms of Wi-Fi.
What is Visible Light Communication?
Visible light is a small portion of the Electromagnetic spectrum. VLC uses visible light between 780-375 nm as carrier for data communication. Using this technology specially designed electronic devices which contains photodiodes can receive data from ordinary light source such as fluorescent lamps and LEDs.
How Li-Fi works?
Data is transmitted by modulating the intensity of light from LEDs which acts as wireless routers. The data fed into LEDs by appropriate embedded software are modulated by rapidly dipping and dimming the electrical current, which is not visible to the naked eye. The modulated light waves is received by photodiodes and then de-modulated into electrical signal form. Appropriate signal processing techniques convert the electrical signal into binary data stream which is transferred to mobile or computer device.
Li-Fi uses a new generation of high brightness LEDs, which can vary in intensity( Switched ON and OFF) without being detectable to the human eye. When the LED is ON, a digital signal 1 is transmitted. When the LED is OFF, a digital signal 0 is transmitted. There is a microcontroller which codes data into LEDs.
Li-Fi enabled LEDs need to be kept always ON for transmitting data. However, they can be faded to below mortal visibility and still they will have enough light waves for transmitting.
Li-Fi vs Wi-Fi
- Both Li-Fi and Wi-Fi transmit data electromagnetically. However, Wi-Fi uses radio waves whereas Li-Fi uses visible light of electromagnetic spectrum.
- Li-FI can transmit data securely and rapidly at a low power level compared to Wi-Fi. Light waves can’t penetrate walls and hence more secure from unethical hacking. However this also means, Li-Fi works in a much shorter range.
- Li-Fi transmits data in parallel and hence has an upper hand in terms of data transfer rate which can reach over 1 GBps whereas Wi-Fi has maximum speed rate of 54 MBps.
- Wi-Fi has interference issues from nearby routers, however Li-Fi is free from such interferences. It can penetrate dense forests and saline waters of sea.
Radio Frequency bandwidth are expensive compared to visible light which is a free spectrum band. There is a spectrum crisis as RF bandwidth has almost reached its capacity. Visible light has 10000 times more spectrum, which can be utilized for data transfer.
Wi-Fi uses radio waves, which can’t be used in electromagnetic sensitive areas such as aircrafts, hospitals and petrochemical stations. Li-Fi uses visible light, which is a safe non-hazardous alternative to Wi-Fi in these environments.
Li-Fi has a high installation cost. Also, it takes a hit in case of public Wi-Fi system where there is a lack of light bulbs for Li-Fi internet. It’s not all gloom! Reports suggest that future iPhone will have Li-Fi capabilities. Li-Fi market is anticipated to reach USD $75 billion by 2023.
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