What Is LiFi? How It Works? WiFi Vs LiFi, Advantages, Drawbacks, LiFi FAQs

LiFi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission. LiFi is designed to use LED light bulbs similar to those currently in use in mini-energy-consumption homes and offices. However, LiFi bulbs are outfitted with chips that modulate imperceptibly for optical data transmission. In LiFi, data is transmitted by LED bulbs and received by the photoreceptors. So the LiFi is an early development module that is capable of transmitting data at a speed of 150 Mbps. Some commercial kits enable that speed to be increased to some extent. In the lab, with stronger LED bulbs and some technologies, researchers have increased that speed to 10 Gbps, which is faster than 802.11ax (the latest WiFi technology).

How Does LiFi Work?

You might have heard about WiFi, which is another technology used to transmit data. WiFi and LiFi are quite similar, as both transmit data electromagnetically. However, WiFi uses radiowaves while LiFi runs on visible light waves. As we know, LiFi is a visible light communication system. This means it accommodates a photodetector to receive light signals and a signal processing element to convert the data into "streamable" content. An LED light bulb is a semiconductor light source, meaning that the constant current of electricity supply to an LED light bulb can be dipped and dimmed up and down at an extremely high speed without being visible to the human eye. When an electric current is fed into an LED light bulb with signal processing technology, it then sends the data embedded in its beam at rapid speed to the photodiode. The tiny changes in the rapid dimming of the light bulb are then converted by the receiver into a binary data stream that we would recognize as web, photo, video, and audio applications that run on internet-enabled devices. So this is how LiFi technology works.

WiFi vs. LiFi

Both LiFi and WiFi technologies are mainly used for internet-based applications. LiFi uses light as a medium for data communication, whereas WiFi uses electromagnetic waves for data communication.

LiFi is optical communication technology, whereas WiFi is a radio communication technology.

LiFi signals cannot pass through walls, so in order to enjoy full connectivity, capable LED bulbs will need to be used throughout the home. Not to mention, LiFi requires the light bulb to be on all the time to provide connectivity, meaning that the light needs to be on during the day.

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Additionally, where there is a lack of light bulbs, there is also a lack of LiFi internet. So LiFi takes the heat when it comes to public WiFi networks. However, by using LiFi instead of WiFi, you negate lots of security problems associated with shared and often overloaded broadband networks. It will also be advantageous in areas where the radio frequency waves do not reach. 

Due to its impressive speeds, LiFi could have a huge impact on the internet of things too. With the data transferred at a much higher level with even more devices able to connect to one another.

LiFi FAQs

Now let us get into the most interesting part, which is frequently asked questions about LiFi- 

How Does LiFi Work?

LiFi is a high-speed bi-directional network and mobile communication of data using light. LiFi consists of multiple light bulbs that form a wireless network. When an electric current is applied to a LED light bulb, it emits a stream of light called photons.LED bulbs are semiconductor devices, which means that the brightness of light flowing through them can be changed at an extremely high speed. This allows us to send a signal by modulating the light at different rates. The signals can then be received by the detector, which interprets the changes in the light intensity of the signal as data. The intensity modulation can not be seen by the human eye, and thus the communication is just as seamless as in other radio systems. Users will be able to connect anywhere there is a LiFi-enabled light. Using this technology, data can be transmitted from an LED light bulb at high speeds.

What Are The Differences Between LiFi And Wifi?

The key differences between WiFi and LiFi are:

Full Forms

LiFi is an abbreviation for Light Fidelity, whereas WiFi is an abbreviation for Wireless Fidelity.

Invented or Coined

WiFi was invented by NCR Corporation with A & T Corporation in 1991, whereas LiFi was coined by Prof. Harald Haas in 2011.

Operation

WiFi transmits data using radio waves with the help of a WiFi router, whereas LiFi transmits data using light with the help of LED bulbs.

Technology

In WiFi, WLAN 802.11/b/g/n/ac/d standard-compliant devices are used. In LiFi, present IrDA devices are used.

Coverage Distance

Coverage distance for WiFi is about 32 meters (varies based on transmission power and antenna type). Coverage distance depends on the region covered by lights under 10 meters because its sensors operate at about 10 meters.

Components Used

In WiFi, for data transmission, we use routers, modems, and access points. In LiFi, we use LED bulbs, LED drivers, and photodetectors.

Applications

WiFi is mainly used for internet browsing with the help of a WiFi hotspot. LiFi can be used in airlines, undersea exploration, etc.

Can We See LiFi Lights Flicker?

The LED lights used to transmit LiFi signals are modulated at such a fast rate that the eye cannot perceive the modulation or "flicker". This is similar to the way our eyes do not interpret the break between film frames in a motion picture. If you see a smooth motion on the cinema screen, you will see an uninterrupted search of LED lights streaming from a LiFi-enabled luminaire. As a comparison, the lowest frequency at which lights are modulated is 1 MHz, and this is 10,000 times higher than the refresh rate of our computer screen.

How Does LiFi Work In A Bright Room With Sunlight?

LiFi can operate in daylight and even in direct sunlight conditions as the modulated light can still be detected. LiFi relies on detecting the fast changes in the light intensity and not on the absolute or slowly varying levels caused by natural disruptions in daylight or sunlight. LiFi technology modulates the light at very high rates, and the sunlight is a constant light source and therefore can be filtered out by the receiver.

How Does LiFi Work When You Turn Off The Lights?

If all power to light is turned off, then there is no LiFi. However, LiFi technology can be enabled to dim low enough that a room will appear dark and still transmit data. This is consistent performance ranging from 10% to 90% illumination.

Will LiFi Work In My Pocket?

No, LiFi does not work in your pocket unless you have a transparent suit. LiFi is a complementary technology that works alongside other wireless technologies such as WiFi. If the light signal to a LiFi-enabled device is below the receiver's threshold, then it will not receive data. In that instance, radio systems or cellular networks, if available, will continue to deliver data. However, the moment the device begins to receive light from a LiFi light bulb, it will resume high-speed data communications using light as an additional communication medium.

How Is LiFi More Secure Than Other Wireless Technologies?

LiFi is significantly more secure than other wireless technologies because light can be contained in a physical space, our doors and windows can be shut, and physical barriers and adjustments can be implemented to contain and protect the light. We can create the conditions that allow us to shut the door on our wireless data. It should be understood that existing security protocols for encryption and authentication can be leveraged in the LiFi system to provide a more secure wireless system.

Is LiFi a Bidirectional Technology, And What Does That Mean?

LiFi is a bidirectional wireless communication technology that allows high-speed transmission in both the uplink and the downlink, simultaneously. An uplink is when information is sent back from a client that is the user's device. This enables bidirectional LiFi communication, which is key to enabling a truly wireless internet browsing experience.

Advantages Of Using LiFi

LiFi has more advanced features, of which a few advantages are: 

The biggest advantage of using LiFi is the high speeds. LiFi offers faster data communication than WiFi and a frequency spectrum 10,000 times larger than that of radio.

LiFi is more secure because data cannot be intercepted without a clear line of sight and it prevents piggybacking.

LiFi eliminates neighboring network interference and does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft. By using LiFi in all the lights in and around a building, the technology could enable a greater area of coverage than a single WiFi router.

Drawbacks to LiFi

Drawbacks to the technology include the need for a clear line of sight. In the absence of a clear line of sight, we face difficulties with mobility.

The requirement is that the light is kept on in order for the system to function.

Applications

The LiFi router applications over WiFi are promising as well as unlimited for wireless communication, which includes traffic management and road safety, medical applications, aviation, communication underwater, elegant lighting, transportation, industrial areas, interior map reading systems for blind people, in dangerous environments or in sensitive regions.

At present, the concept of LiFi technology is attracting a lot of wireless internet users due to its genuine appeal. Furthermore, it can be explored for laptops and gadgets which can be transmitted through the light in the room using LiFi.

What Are The Advantages Of LiFi Over WiFi?

Data Transfer Speed 

WiFi offers data transfer speeds ranging from 150Mbps to a maximum of 2Gbps. The data transfer speed for LiFi is about 1 Gbps.

Privacy

WiFi data transfer through radio waves, and as walls cannot block radiowaves, we need to employ more techniques to achieve secure data transfer. 

LiFi uses LED bulbs for data transmission and light is blocked by the walls, hence LiFi provides a more secure data transfer than WiFi.

Frequency of Operation

The frequencies of operation for WiFi are 2.4Ghz, 4.9Ghz, and 5Ghz, where the frequency range for LiFi is 10,000 times greater than the frequency spectrum of the radio.

Data Density

WiFi works in less dense environments due to interference-related issues, whereas LiFi works in highly dense environments.