Li-Fi is a new way of wireless communication which uses LED lights to transmit data wirelessly. The data flow speed of this wireless data communication technology is quite high and has low cost installation. This post will discuss about what is Li-Fi technology, how it works, its applications, advantages, limitations and difference between Li-Fi and Wi-Fi.
It is well accepted that transmission of data is one of the most important day to day activities in today’s fast changing world. Some problems that is normally faced are:
- Slow connection to the Internet when multiple devices are connected
- Unavailability of fixed bandwidth due to overcrowding does not allow high data transfer rates.
This technology can be a solution to all these problems. Researches are going on to develop this technology on a broad scope.
Fig. 1 – Introduction to Li-Fi Technology
What is Li-Fi Technology
The term Li-Fi (Light and Fidelity) refers to Visible Light Communication (VLC) technology. This technology uses a part of the electromagnetic spectrum that is still not utilized generally i.e. the Visible Spectrum.
In simple terms, LiFi is a light-based Wi-Fi. This technology has a much broader spectrum for transmission compared to conventional methods of wireless communication which uses radio waves.
The basic ideology of this technology is transference of data using LED light of varying intensities. It uses transceivers fitted with LED lamps that can transmit and receive information. This results in adding new and unutilized bandwidth of visible light and may offer additional frequency band than those bands which are available for RF communication.
Fig. 2 – Uses of Electromagnetic Spectrum
Since LiFi uses the visible spectrum, concerns of adverse effects of electromagnetic waves (associated with Wi-Fi technology) gets alleviated. Security concerns are also reduced as data or information on the Internet cannot be accessed in the absence of light.
How Does a Li-Fi Work
Li-Fi is a Visible Light Communications (VLC) system and such a system has two qualifying components:
- One device with a Photo-diode able to receive light signals.
- A light source coupled with a Signal Processing Unit.
The VLC system signals work by switching bulbs on and off within nanoseconds such that human eyes are unable to notice it. High brightness white LED acts as a light source i.e. as transmission source. A silicon photo-diode with good response to visible light is the receiving element.
Fig. 3 – How Does the Li-Fi Technology Work
LEDs are switched on and off to generate digital strings of combination of 1s and 0s. To generate a new data stream, data is encoded in the light by changing the flickering rate of the LED, which is used as the source. The LED output appears constant to the human eye by the fast flickering rate of the LED.
VLC data rate is increased by parallel data transmission using an array of LEDs where each LED transmits a different data stream.
Applications of Li-Fi Technology
This technology has a wide range of applications such as:
- Public Internet access using existing LED lighting.
- Auto-piloted cars that communicate through their LED based headlights.
- Connecting with specialists across the globe from the operation theater.
- Since it uses just the light, it can be used safely in locations or areas where the presence of radio waves raises concerns of security.
Fig. 4 – Advantages of Li-Fi Technology
Advantages of Li-Fi Technology
Advantages of Li-Fi technology are:
- Efficiency: Efficient use of energy consumption due to the use of LED illumination which are already in use for lighting purpose. Hence the transmission of data will require negligible additional power/ energy.
- High speed: The technology uses bandwidth that is not is use currently. Hence, low interference, wider bandwidths and high-intensity output are its key data features.
- Availability: As the light source is available everywhere, availability is not an issue. Hence, wherever there is a light source, there will be Internet.
- Cost Efficient: This technology requires few components for its working. The technology also uses negligible additional power for data transmission. Overall, utilization of this technology becomes cost efficient.
- Security: As light cannot pass through opaque structures, LiFi internet is available only to those within a confined area. This internet cannot be intercepted and misused outside the area under operation.
- Futuristic: This technology has a great scope in future due to the extensive growth in the use of LEDs. Overall, it is considered a sustainable model for Internet access as it incurs lower cost and offers higher efficiency.
Limitations of Li-Fi
Some of the major limitations of Li-Fi are:
- Access of internet is limited by the presence of a light source.
- Data transmission speed can get lowered because of interference of natural light (sunlight) and normal electric light.
- Since light cannot pass through opaque objects, obstacles on pathways can affect data transmission.
- It has a much shorter range than Wi-Fi.
- Not yet developed for mass scale adoption.
Fig. 5 – Strength and Weakness of Li-Fi Technology
What is the difference between Wi-Fi and Li-Fi Technology
Wi-Fi offers highest speed access to internet among the current technology. However, if we compare Li-Fi with Wi-Fi, we find the following key differences:
|Spectrum Used||Visual Light||Radio Frequency|
|Range||Depends on light intensity, can be lower than Wi-Fi||Less than 200 meters|
|Cost||High installation cost, low regular usage cost||Low cost|
|Security||High||Less (compared to Li-Fi)|
|Data transfer speed||Higher (compared to Wi-Fi, can be up to 100 times faster)||High|
|Availability||Yet to be available for commercial use||Widely available|
Due to the speed and security offered by Li-Fi technology compared to Wi-Fi, Li-Fi is here to stay and likely to be used widely.