Hey friends, welcome So, in this post, we will learn about Li-Fi technology, which is the abbreviation of the term Light Fidelity. So, in simple terms, we can say that this Li-Fi technology is nothing but light-based Wi-Fi technology. And as we know, this Wi-Fi is fully networked, bi-directional wireless communication technology. Where data is being transmitted using radio waves. While in the case of Li-Fi technology, the information is transmitted in visible light using the LED light source. So, these household LED bulbs and LED lamps used as a light source can also transmit the data. So, first of all, let's understand how this Li-Fi technology works. So, if you see any LED light source, if you provide the constant current to this LED bulb, it gives continuous illumination or constant brightness. So, as we change the current flowing through the LED bulb, the lighting or brightness of this bulb will change. So, this principle is used for transmitting the data wirelessly using this Li-Fi technology.
So, if no current or minimum current flows through this LED bulb, the brightness of this LED source will be minimal. And that will be treated as digital 0. So, digital 0 will be transmitted at the receiver side. Similarly, when the light bulb is ON, or we can say that if the maximum amount of current is flowing through this LED bulb, the illumination or brightness of the LED bulb will be maximum. And that will be treated as digital 1. So, whenever the LED is ON so that digital one will be transmitted at the receiver side. So, in this way, by flickering the LED light source very rapidly, we can transmit the data in the form of 1's and 0's to the receiver. And if this flickering is happening a million times per second, we can not see this flickering with our naked eyes. And we can treat this LED bulb source as a normal regular bulb source. So, now let's see the schematic of the Li-Fi transmitter and receiver system. So, as you can see, the data from the webserver or the Internet will first go to the MODEM, which provides the necessary modulation to the incoming data stream. Then this modulated data is fed to the LED driver, which changes the driving current for this LED bulb according to the incoming streaming data. If you see, the optically received data is first converted into the electrical signal using the photo receiveror photodiode at the receiver end. And after the signal conditioning, this data is being fed to the computer or laptop. So, to receive this incoming data, at the receiver side, we require the Li-Fi dongle, which consists of a photoreceiver and a transmitter. Now this infrared transmitter can be used to transmit the uplink data back to the LED source. Now, one such company which provides the complete-Fi solution is Pure LiFi. Which generally makes these Li-Fi dongles. So, now as we know how this Li-Fi technology works, now let's see the advantages of this Li-Fi technology over the other wireless communication technologies. So, these are some of the benefits of the Li-Fi technology over the other wireless communication technologies.
So, first, let's talk about speed. So far, the researchers have achieved a rate of up to 10 Gbps in the lab-scale prototype models. And this speed can further be enhanced by using the array of LED sources or using the multiple colours of LEDs like RGB LEDs, where each LED source can transmit the data up to 10 Gbps. So, using such technologies, the researchers have achieved a maximum speed of up to 100 Gbps. So, now let's compare its rate with other wireless communication technologies. So, if we compare it with 4G/LTE or particularly the LET advanced, the maximum achievable speed under this LTE advanced is 1 Gbps for the stationary user and 100 Mbps for the mobile user. But all these speeds are the theoretically achievable maximum speed. But actual speed may be much lesser compared to this theoretically achievable maximum speed. So, if you see the countries which provide the fastest Internet in the world, the average 4G/LTE speed in such countries is in the range of 40-50 Mbps, which is much lesser compared to the speed at which the Li-Fi provides. So, now let's compare the rate of Li-Fi with Fi. Now, in the case of Wi-Fi, if you see the standard IEEE 802.11.ac, the maximum speed which this standard can support is 1.3 Gbps. And that is in the 5 GHz band, which is almost100 times lesser than the speed the Li-Fi supports. And if you see the other Wi-Fi standard, which is not commercially available yet, that is IEEE 802.11.ad, the maximum speed this standard can support is 7 Gbps. And all the speeds which are mentioned over here are the theoretically achievable top speeds. But the actual rates may be relatively lesser compared to the theoretically achievable maximum speeds. And still, if we consider the full speed supported by this Wi-Fi technology, the Li-Fi technology is still ten times faster than this Wi-Fi technology. Well, right now, the rate which is provided by the Wi-Fi technology is sufficient for our day to day life. But as we are moving in the era of the Internet of Things, where each device can communicate with each other, soon you will find that the speed provided by the Wi-Fi technology is insufficient. And you will require the insane speed like100 Gbps, which as of now looks like a dream. So, next, if you see the electromagnetic spectrum, the bandwidth of the radio wave is up to 300 GHz. But if you know the bandwidth of this visible spectrum alone, the bandwidth of this visible spectrum is around 300 THz, which is almost 1000 times more than the bandwidth of the radio waves. So, not only you can achieve a higher speed, but also you will not find any electromagnetic radio interference. So, now in the case of Li-Fi, as we are using the visible light source, the visible light source can not cross the walls, unlike the case of Wi-Fi, where the radio waves can transmit across the borders. So, in this way, this Li-Fi technology provides one more layer of security. So, these are the advantages of this Li-Fi technology over the other wireless communication technologies. So, now let's see the different applications of this Li-Fi technology. So, this Li-Fi technology can be used in hospitals.
This Li-Fi technology provides very high-speed internet communication, so real-time health monitoring of the patient will be possible. So, apart from that, this Li-Fi technology can be used for underwater communication. Also, using this technology, the vehicles can communicate using the front and the rear lights. And using this technology, we can prevent accidents. Also, this Li-Fi technology can be used in aeroplanes to provide the Internet to the passengers. And not only that if this technology is fitted into our street lights, then even our street lights can provide us high-speed Internet. So, these are some of the applications in which this Li-Fi technology can be used. But still, if you see, this Li-Fi technology is futuristic. That means, commercially, no available products provide the insane speed up to 10 Gbps or 100Gbps. So, in the upcoming years, we might see the technologies or devices which support this Li-Fi technology. So, right now, as we are witnessing the Free Wi-Fi Zone in the cafeteria, in future, we might see a Free Li-Fi zone in the restaurant. So, now the bigger question is if Li-Fi is the future of the Internet, then what about existing wireless technologies. So, the answer is that in future also all the existing technologies will remain. And instead, this Li-Fi technology will complement the current technologies because this Li-Fi is short-range communication. So, using this technology, we can not cover the entire area using light. So, grossly we can say, when you require large coverage, we will still prefer Wi-Fi and 4G/LTE, but in short-range, like in the case of our room or hotel or even offices, we can still choose this Li-Fi technology. So, I hope in this post you understand this Li-Fi technology.