Li-Fi Explained

Summary

This video from the All About Electronics YouTube channel delves into Li-Fi technology, an innovative light-based wireless communication system. Utilizing LED lights to transmit data at speeds up to 100 Gbps, Li-Fi offers significant advantages over Wi-Fi, including higher speeds, no electromagnetic interference, and enhanced security due to its inability to penetrate walls. The technology has potential applications in various fields, including healthcare, underwater communication, and in-vehicle networking. While currently experimental, Li-Fi is poised to complement existing wireless technologies, especially in scenarios requiring high-speed, short-range communication.

Takeaways

• 💡 Li-Fi technology stands for Light Fidelity and is a light-based wireless communication technology.
• 🌐 Unlike Wi-Fi, which uses radio waves, Li-Fi transmits data through visible light using LED sources.
• 💡 Data transmission in Li-Fi occurs by rapidly flickering the LED light, representing binary data (1s and 0s).
• ⚡ Researchers have achieved data transmission speeds up to 10 Gbps in lab conditions with Li-Fi.
• 🔍 Li-Fi has the potential to reach speeds up to 100 Gbps using arrays of LEDs or multiple color LEDs (RGB).
• 📶 Li-Fi offers higher speeds compared to Wi-Fi and 4G/LTE, with theoretical maximum speeds significantly greater.
• 🔒 Li-Fi provides an additional layer of security since visible light cannot pass through walls, unlike radio waves.
• 🏥 Potential applications of Li-Fi include hospitals for real-time health monitoring, underwater communication, vehicular communication, and internet access in airplanes and streetlights.
• 🌐 Despite its advantages, Li-Fi will complement rather than replace existing wireless technologies due to its short-range limitations.
• 🚀 The future may see widespread adoption of Li-Fi, with possible scenarios like Free Li-Fi Zones in public spaces.

Q & A

What is Li-Fi technology?

Li-Fi, short for Light Fidelity, is a light-based wireless communication technology that transmits data using visible light from LED sources, similar to how Wi-Fi uses radio waves.

How does Li-Fi technology transmit data?

Li-Fi transmits data by modulating the brightness of LED lights. Rapid changes in brightness, imperceptible to the human eye, represent digital 1s and 0s that are decoded by the receiver.

What is the principle behind transmitting data with Li-Fi?

The principle involves changing the current flowing through an LED bulb to alter its brightness. Minimum brightness represents a digital 0, and maximum brightness represents a digital 1.

What are the components of a Li-Fi transmitter and receiver system?

The transmitter includes a modem for data modulation and an LED driver to adjust the LED current. The receiver has a photo receiver or photodiode to convert light signals into electrical signals, and a Li-Fi dongle with a photo receiver and an IR transmitter for uplink data.

What is the role of a Li-Fi dongle in the receiver system?

A Li-Fi dongle in the receiver system contains a photo receiver to capture the light signals and an IR transmitter to send uplink data back to the LED source.

What is the maximum speed achieved by Li-Fi technology in lab-scale prototypes?

Researchers have achieved speeds up to 10 Gbps in lab-scale prototypes, with potential for further enhancement using multiple LED sources or RGB LEDs.

How does Li-Fi compare to 4G/LTE in terms of speed?

Li-Fi significantly outperforms 4G/LTE, with lab-scale prototypes reaching 10 Gbps compared to the theoretical maximum of 1 Gbps for stationary users and 100 Mbps for mobile users in 4G/LTE.

What are the advantages of Li-Fi over Wi-Fi in terms of speed?

Li-Fi offers much higher speeds than Wi-Fi. For example, the Wi-Fi standard IEEE 802.11.ac supports a maximum of 1.3 Gbps, which is far less than the speeds Li-Fi can achieve.

Why is Li-Fi technology considered more secure than Wi-Fi?

Li-Fi is more secure because it uses visible light, which cannot pass through walls, unlike radio waves used by Wi-Fi. This limits the range of communication and reduces the risk of unauthorized access.

What are some potential applications of Li-Fi technology?

Li-Fi can be used in hospitals for real-time health monitoring, underwater communication, vehicle-to-vehicle communication for safety, in-flight internet on airplanes, and even in street lights for public Wi-Fi.

How does Li-Fi technology complement existing wireless technologies?

Li-Fi is a short-range communication technology that can complement Wi-Fi and 4G/LTE for scenarios requiring high-speed, secure connections in confined spaces, while Wi-Fi and 4G/LTE are better for broader coverage.

Outlines

00:00

🌟 Introduction to Li-Fi Technology

This paragraph introduces the Li-Fi (Light Fidelity) technology, which is a light-based alternative to Wi-Fi. It explains that Li-Fi uses visible light from LED sources to transmit data, with varying brightness levels representing digital 0s and 1s. The technology's potential for high-speed data transmission, up to 10 Gbps in lab settings and even 100 Gbps with advancements like RGB LEDs, is highlighted. The paragraph also outlines the basic components of a Li-Fi system, including the modem, LED driver, photo receiver, and the Li-Fi dongle, and mentions Pure LiFi as a company providing Li-Fi solutions.

05:04

🚀 Advantages and Applications of Li-Fi

This paragraph delves into the advantages of Li-Fi over other wireless communication technologies, focusing on its superior speed, which can reach up to 100 Gbps, significantly outperforming 4G/LTE and Wi-Fi standards. It also discusses the broader bandwidth available in the visible light spectrum compared to radio waves, offering greater potential for data transmission without electromagnetic interference. The paragraph further explores the security benefits of Li-Fi due to its inability to penetrate walls, unlike Wi-Fi. Various applications of Li-Fi are presented, such as in hospitals for real-time health monitoring, underwater communication, vehicle-to-vehicle communication for safety, in-flight internet on airplanes, and even using street lights for public internet access. The potential for Li-Fi to complement existing technologies in short-range communications is acknowledged, with a look towards future developments and widespread adoption.

Keywords

💡Li-Fi

Li-Fi, short for Light Fidelity, is a wireless communication technology that uses visible light to transmit data. It is a key focus of the video, which explains how Li-Fi operates differently from Wi-Fi by utilizing LED light sources for data transmission. The video highlights Li-Fi's potential for high-speed data transfer, up to 100 Gbps, and its advantages over other technologies.

💡LED light source

LED, or Light Emitting Diode, is a type of semiconductor light source that emits light when an electric current passes through it. In the context of Li-Fi, LED bulbs are used not only for illumination but also as a medium for transmitting data through changes in brightness, which represent digital 0s and 1s.

💡Data transmission

Data transmission refers to the process of sending information from one point to another, which is central to the Li-Fi technology discussed in the video. The script explains how data is transmitted using the flickering of LED lights at a rate imperceptible to the human eye, thus enabling high-speed communication.

💡Modem

A modem is a device that modulates and demodulates signals to enable communication over a network. In the Li-Fi system described in the video, the modem is responsible for preparing the data for transmission by the LED driver, highlighting its role in the setup of a Li-Fi network.

💡Photodiode

A photodiode is a type of photodetector that converts light into an electrical current. In the Li-Fi receiver system, the photodiode captures the light signals emitted by the LED and converts them back into electrical signals for further processing, illustrating its importance in receiving Li-Fi data.

💡Speed

The video emphasizes the high-speed capabilities of Li-Fi technology, with lab-scale prototypes achieving speeds up to 10 Gbps and theoretical potential reaching 100 Gbps. This speed is contrasted with Wi-Fi and 4G/LTE technologies, positioning Li-Fi as a promising solution for future high-speed communication needs.

💡Electromagnetic interference

Electromagnetic interference refers to the disruption caused by electromagnetic radiation, which can affect the performance of electronic devices. The video points out that Li-Fi, using visible light, does not suffer from such interference, offering a more stable communication channel.

💡Security

The video mentions that Li-Fi provides an additional layer of security because the visible light cannot penetrate walls, unlike radio waves used in Wi-Fi. This property makes Li-Fi more secure for applications where data privacy is crucial.

💡Internet of Things (IoT)

The Internet of Things is a concept where everyday objects are connected to the internet, allowing them to send and receive data. The video suggests that Li-Fi's high-speed capabilities will be beneficial in the era of IoT, where the need for fast and reliable communication among devices is expected to grow.

💡Applications

The video outlines various applications of Li-Fi technology, including hospitals for real-time health monitoring, underwater communication, vehicle-to-vehicle communication for safety, in-flight internet on airplanes, and even street lights providing high-speed internet. These examples illustrate the diverse potential uses of Li-Fi in different sectors.

💡Futuristic technology

The term 'futuristic technology' is used in the video to describe Li-Fi as an emerging solution that is not yet widely commercially available. It suggests that while Li-Fi shows great promise, it is still in the early stages of development and adoption, with the expectation that it will complement existing technologies in the future.

Highlights

Li-Fi technology, or Light Fidelity, is a light-based wireless communication technology similar to Wi-Fi but using visible light instead of radio waves.

Data transmission in Li-Fi is achieved through the modulation of LED light brightness, representing digital 0s and 1s.

Li-Fi uses household LED bulbs and lamps as light sources to transmit data, making them dual-functional devices.

The Li-Fi transmitter system involves a modem for data modulation and an LED driver to adjust the LED current based on data streams.

At the receiver end, a photodiode or photo receiver converts the optical data into an electrical signal for further processing.

A Li-Fi dongle with a photo receiver and an IR transmitter is required at the receiver side for data reception and uplink communication.

Pure LiFi is a company that provides complete Li-Fi solutions, including Li-Fi dongles.

Li-Fi has demonstrated speeds of up to 10 Gbps in lab settings, with potential for further enhancement using RGB LEDs.

Li-Fi's speed far exceeds that of 4G/LTE and Wi-Fi, with lab prototypes achieving up to 100 Gbps.

The visible light spectrum used by Li-Fi has a bandwidth of around 300 THz, significantly larger than the radio wave bandwidth.

Li-Fi provides an additional layer of security as visible light cannot penetrate walls, unlike radio waves.

Li-Fi technology can be applied in various fields such as hospitals for real-time health monitoring, underwater communication, and vehicle-to-vehicle communication.

Li-Fi can be used in airplanes to provide internet to passengers and in street lights to offer high-speed internet access.

Although Li-Fi is a futuristic technology, current commercial products do not yet support the extreme speeds demonstrated in labs.

Li-Fi is expected to complement existing wireless technologies rather than replace them, due to its short-range communication的特性.

In the future, we might see Free Li-Fi zones in public spaces, similar to current Free Wi-Fi zones.

Li-Fi's short-range communication makes it suitable for areas requiring high-speed data transfer in confined spaces like rooms or offices.

Transcripts

Hey friends, welcome to the YouTube channel ALL ABOUT ELECTRONICS.

So, in this video, we will learn about the Li-Fi technology.

Which is the abbreviation of 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 the radio waves.

While in the case of Li-Fi technology, the data is transmitted in the form of visible

light using the LED light source.

So, this house hold LED bulbs and LED lamps which are used as a light source can also

be used to 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 provides the constant illumination or constant brightness.

So, as we change the current that is flowing through the LED bulb, the illumination or

brightness of this bulb will change.

So, this princi[ple is used for transmitting the data wirelessly using this Li-Fi technology.

So, if no current or minimum current is flowing through this LED bulb then, the brightness

of this LED source will be minimum.

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 then 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 digital 1 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 at million times per second then we can not see this

flickering by our naked eyes.

And we can treat this LED bulb source as normal regular bulb source.

So, now let's see the schematic of Li-Fi transmitter and receiver system.

So, as you can see, the data which is coming from the web server or the internet first

it will 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.

At the receiver end, if you see, the optically received data is first converted into the

electrical signal using the photo receiver or photo diode.

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 photo receiver as well as IR 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 Li-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 the some of the advantages of the Li-Fi technology over the other wireless

communication technologies.

So, first let's talk about the speed.

So, so far the researchers have achieved the speed up to the 10 Gbps in the lab scale prototype

models.

And this speed can further be enhanced by using the array of LED source or by using

the multiple colours of LEDs like RGB LEDs, where each LED source is able to transmit

the data up to the 10 Gbps.

So, using such technologies, the researchers have achieved the maximum speed up to the

100 Gbps.

So, now let's compare its speed 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 which is provided by the Li-Fi.

So, now let's compare the speed of Li-Fi with Wi-Fi.

Now, in case of Wi-Fi, if you see the standard IEEE 802.11.ac, the maximum speed which can

be supported by this standard is 1.3 Gbps.

And that is in the 5 GHz band, which is almost 100 times lesser compared to the speed which

is supported by the Li-Fi.

And if you see the another Wi-Fi standard, which is not commercially available yet, that

is IEEE 802.11.ad, the maximum speed which can be supported by this standard is 7 Gbps.

And all the speeds which are mentioned over here are the theoretically achievable maximum

speeds.

But the actual speeds may be quite lesser compared to the theoretically achievable maximum

speeds.

And still, if we consider the maximum speed which is supported by this Wi-Fi technology,

the Li-Fi technology is still 10 times faster compared to this Wi-Fi technology.

Well, right now the speed 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 Internet of Things, where each device is able to communicate

with each other, soon you will find that the speed which is provided by the Wi-Fi technology

is insufficient.

And you will require the insane speed like 100 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 see the bandwidth of this visible spectrum alone, the bandwidth of this visible

spectrum is around 300 THz.

Which is almost 1000 times more compared to the bandwidth of the radio waves.

So, not only you can achieve the higher speed but also you will not find any kind of 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 are able

to transmit across the walls.

So, in this way, this Li-Fi technology provides the 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 the hospitals.

As this Li-Fi technology is providing very high-speed internet communication, so the

real time health monitoring of the patient will be possible.

So, apart from that this Li-Fi technology can be used for the under water communication.

Also, using this technology, the vehicles can communicate with each other using the

front and the rear lights.

And using this technology, we can prevent the accidents.

Also, this Li-Fi technology can be used in the 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 the some of the applications in which this Li-Fi technology can be used.

But still, if you see, this Li-Fi technology is the futuristic technology.

That means, the commercially there are no products which are available which provides

the insane speed up to the 10 Gbps or 100 Gbps.

So, in the upcoming years, we might see the technlgies or devices which support this Li-Fi

technology.

So, right now, as we are seeing the Free Wi-fi Zone in the cafeteria, in future we might

see Free Li-Fi zone in the cafeteria.

So, now bigger question is if Li-Fi is the future of internet then what about the already

existing wireless technologies.

So, the answer is that in future also all the existing technologies will remain.

And rather this Li-Fi technology will complement all the existing technologies.

Because this Li-Fi is short range communication.

So, using this technology we can not cover the entire area using the light.

So, grossly we can say, when you require large coverage, we will still prefer Wi-Fi and 4G/LTE

but in short coverage, like in the case of our room or hotel or even offices, we can

still prefer this Li-Fi technology.

So, I hope in this video, you understood about this Li-Fi technology.