What is Li-Fi, and where is Li-Fi Technology used

The use of the internet is prevalent in today's society. We use the internet for nearly anything these days, from entertainment, retail, healthcare, and so on. In a short time, everything would become digital.

According to research, around 5.56 billion people were connected to the Internet as at January 2025, this is equivalent to 67.9 percent of the world's total population, compared to 5.43 billion people in January 2024. There's no doubt that this number will continue to grow.

With the rapid increase in internet usage, Wi-Fi (Wireless Fidelity) may struggle to keep up as the demand for faster networks and higher data capacity rises. This is especially true with advanced technologies like IoT, which we see being integrated in houses, manufacturing, and transportation.

Despite these advancements in speed and connectivity, we still experience network challenges in one way or another.

Li-Fi is said to be the solution to overcome the problem of connectivity. Compared to Wi-Fi that uses radio waves transmission, Li-Fi uses Light waves instead, making it 100 times faster.

Light Fidelity (Li-Fi) is a high-speed bidirectional wireless communication that uses light to transmit data.

This technology is based on VLC (Visible Light Communication), which is an optical technology that uses light rays for data transmission by illumination. It uses fast pulses of light undetected by human eyes.

The main components of a VLC system include;

• Light Emitting Diodes or any light source, which acts as the transmitter.

• A silicon Photodiode, which is the detector that responds to the visible wavelength.

• A Communication channel.

Li-Fi was first presented in 2011 by Professor Harold Haas, showing how LED light bulbs could transmit data. In his demonstration, he connected a server with stored videos to a Li-Fi router, which was linked by a cable to an LED lamp. The lamp provided light while also granting access to the server.

On the receiving end, he connected a Li-Fi dongle (a device with a receiver and an LED transmitting in the infrared spectrum) into a computer, allowing it to connect to the Li-Fi router.

When the LED lamp transmitted light, the dongle received the signal, enabling the computer to access the video from the server - demonstrating wireless communication through light.

There's an ongoing discussion about 6G revolutionizing network speed for wireless connectivity. However, this technology is still under development and there are certain concerns.

For instance, Wi-Fi, which relies on radio waves, has been allegedly linked to certain health issues. Additionally, as the demand for faster connection and greater data capacity increases, there may be insufficient radio frequency resources to accommodate it.

There's also concern that radio waves do not travel well under certain environments like water, making it inefficient in some ways. Additionally, there are concerns about the capacity of WI-FI and a few of these concerns include;

Capacity – The radio wave frequency spectrum is getting congested, especially with IoT and Artificial intelligence becoming a huge part of our lives.

Efficiency: The cellular base station consumes a lot of energy not just because it transmits radio waves but because a lot of energy is used to cool the base stations.

Security: Radio waves can be intercepted and used for malicious activities; it is more susceptible to attacks.

The idea of Li-Fi is that connecting to a network would be as easy as turning on your light bulb. Every LED light or light source would become an internet access point, with unprecedented bandwidth of data, keeping data safe and repurposing energy for wireless communication.

According to Haas, the visible light spectrum is a thousand times larger than the entire radio spectrum. Transmitting data using light-emitting nodes (LED) would be low-cost and highly efficient because light is sustainable.

Efficiency: LED consumes less energy, it is low cost, because it requires fewer components compared to radio technology. Because they already serve as a source of illumination, no additional power is required. Also, the concerns regarding Wi-Fi being unavailable in certain environments like underwater would be eliminated.

Capacity: Lights from cars, street lamps are used as hotspot, meaning that any light can spread the internet using VLC, which reduces the architecture cost. High data rates from 500mbps to 30Gb per minute can be achieved due to low interference, high device bandwidths, and high optical output.

Safety: There are no health concerns associated with Li-Fi, unlike radio waves that can interfere with electronic circuits and have effects on humans and the environment.

Security: It would be difficult to eavesdrop on Li-Fi signals because they don't travel through walls and are constrained to a specific area. Li-Fi signals cannot be picked up unless the intruder is in the same space.

Limited Range: Li-Fi has limited range, unlike Radio signals, Li-Fi cannot penetrate through obstacles, and for effective communication, the receiver must be within the light beam of the Li-Fi transmitter, this means any blockage can disrupt the signal.

Limited Compatibility: Li-Fi is still an emerging technology and modern devices are not compatible with Li-Fi technology because they are designed for Wi-Fi connectivity.

Dependent on Light: Li-Fi requires exposure to light, this means it cannot work in dark areas or if there’s any form of obstruction.

Li-Fi would play a significant role in various industries, including smart cities, IoT, and healthcare by providing high-speed and secure communication. Here are a few applications of Li-Fi technology;

Under Water Communication:

Li-Fi can function underwater, unlike Wi-Fi, which struggles due to strong signal absorption that prevents radio frequencies from travelling long distances.

However, Li-Fi is being explored as an alternative to sound-wave-based communication, which is commonly used underwater. For instance, submarines could use headlamps to communicate with each other, and Li-Fi could enable efficient communication during underwater surveillance and military operations.

Aviation:

Li-Fi can be used for safe in-flight connectivity because it would not disrupt the communication signal like Wi-Fi. However, this can be expensive to implement because it may require satellite communication, onboard Li-Fi networks, etc.

Traffic Management:

Li-Fi would make it possible to adjust signals dynamically and analyse traffic in real time using LED street lights. Li-Fi enabled headlights or taillights can exchange data, for instance, cars can communicate speed and direction to prevent collisions.

Internet of Things:

Li-Fi can be integrated into smart homes, and smart factories, to provide interference-free connectivity between devices and IoT sensors. By using LED light for data transmissions, it can communicate with automated machinery to optimize manufacturing processes

Medical Applications:

Li-Fi could be used in hospitals that require lack of Radio Frequency (RF) signals, which can affect medical equipment, for instance, the use of Wi-Fi can block signal from monitoring devices causing danger to the patient.

Augmented Reality Application:

Li-Fi transmits data without lag, it can enable Augmented Reality (AR) devices to connect seamlessly, for instance, factory technicians can wear AR glasses to receive real-time instructions and diagrams, allowing them to perform tasks accurately

Defence and Government:

Li-FI cannot be detected and has a near-zero electromagnetic radiation (EM) signals making it secure against signal interception and jamming. It is reportedly being used by the US army for mission critical communication.

This technology is still under development, and companies like pureLiFi and Oledcom are actively working to make it commercially available.

When comparing these technologies, we see that both have their advantages and disadvantages. Wi-Fi is great for broader coverage while Li-Fi is extremely fast for short distances. Li-Fi can be useful in areas where Wi-Fi is limited, and vice-versa, which makes them complementary.

As the world becomes more digital, concerns are growing about data consumption and increasing demand for high-speed networks. IoT devices like temperature sensors, heart rate monitors are connected wirelessly everywhere.

An increase in demand for data equals an increase in vulnerability. Our personal information, and digital footprint, are all linked to the internet. Li-Fi is a promising alternative to Wi-Fi which aims to offer a faster, safer, and more efficient communication solution.