Li-Fi (Light Fidelity) - data transfer technology

Li-Fi (Light Fidelity) is a two-way wireless communication that uses visible light to transmit data instead of traditional radio frequencies, which are used, for example, in Wi-Fi and LTE connections.

Li-Fi transmits data by creating binary codes using light flickers in the optical range using conventional LED lamps, which are used for lighting, receivers help convert photons back into information. At the same time, users do not see flickering, since it is provided at a frequency above 60 Hz and is not perceived by human vision.

As Li-Fi routers, special LED bulbs installed in homes and offices are used. According to information published on the official Li-Fi website, sunlight is not an obstacle to the technology. At the same time, it will not be possible to use it in a dark room - the illumination should be at least 10%. The device will not need direct visibility of the light bulb, as it can "pick up signals from light reflecting from other surfaces."

It is assumed that Li-Fi will allow data transfer 100 times faster than Wi-Fi.

The peculiarity of the technology is that Li-Fi uses uplink and downlink communication channels: using light signals, data is transmitted both to the user and from him to the Li-Fi receiver. This allows you to strengthen the security of the transmitted information through such a connection, since attackers will have to hack both channels and, moreover, should be in the same room as the desired computer.

Advantages and disadvantages

Advantages of Li-Fi:

• Simplicity and cheapness of implementation;
• No license is required to use;
• Lack of radio band in the technology;
• Visible light does not conflict with other electromagnetic frequencies, so Li-Fi technology can be used, for example, on board an aircraft or in medical institutions.

Disadvantages of Li-Fi:

• Mandatory line of sight between receiver and transmitter;
• With bright light, for example, sunlight, malfunctions and errors are possible.

History of development

2023

IEEE adopts Li-Fi 802.11bb standard - it is much safer and 100 times faster than Wi-Fi

On July 12, 2023, the Non-Profit Association Institute of Electrical and Electronics Engineers (IEEE) announced the adoption of the Li-Fi 802.11bb standard for wireless data transmission via light in open space. The technology is said to be much safer and 100 times faster than Wi-Fi.

Instead of traditional radio frequencies, the system uses light in the optical range, and LED lamps serve to generate signals. The radiation enters a special receiver installed in the client equipment. For users, such flickering is completely invisible.

IEEE adopts Li-Fi 802.11bb standard - it is much safer and 100 times faster than Wi-Fi

The project says Li-Fi provides "faster, more reliable wireless connectivity with unprecedented levels of security compared to conventional technologies such as Wi-Fi and 5G." In particular, the data link capacity can be up to 224 GB/s.

Dominic Schulz, head of Li-Fi development at the Fraunhofer Institute for Telecommunications (Fraunhofer HHI), says line-of-sight light propagation improves security by preventing signals from penetrating walls. This reduces the risk of interference and listening, as well as allowing indoor navigation to within a centimeter.

In general, with the advent of the IEEE Std 802.11bb standard, the Li-Fi platform receives the first solution that meets mass market requirements, such as low cost, low power consumption and significant amounts of information transmitted. The solution integrates easily with existing infrastructure. Fraunhofer HHI offers all the building blocks for modern Li-Fi systems, adapts devices for special applications and conducts field tests in real-world scenarios. The new standard lays the foundation for the widespread adoption of Li-Fi technology and paves the way for interoperability between Li-Fi and Wi-Fi systems.^[1]

Connection of lighting systems via Li-Fi

PureLiFi, Fraunhofer HHI and Philips, which are working on the technology, were already able to integrate Li-Fi equipment into conventional lighting systems in homes and offices by July 2023. Some companies also suggest using street lights, headlights and brake lights to transmit data.

2018: Philips tests Li-Fi in Paris

In March 2018, Signify, formerly Philips Lighting, announced real-world testing of Li-Fi technology. She began to be tested in Paris in the offices of the French company Icade, specializing in real estate investment.

Signify has offered Li-Fi-enabled lighting fixtures that provide broadband at speeds up to 30Mbps regardless of lighting quality. This speed is quite enough for comfortable video communication or watching several movies in HD quality at the same time.

Philips tests faster Wi-Fi alternative in offices

While radio frequencies become congested, the visible spectrum remains an unused resource with high bandwidth suitable for the stable connection of a large number of IoT devices, said Signify Director of Innovation Development Olivia Qiu.

In addition to the functions of a modem for wireless data transmission, Signify LiFi lights can be used simultaneously for energy-saving lighting of rooms.^[2]

2011: Technology testing begins

Li-Fi technology was first introduced in 2011, the term is short for "Light Fidelity." It uses visible, infrared or ultraviolet light instead of radio frequencies for high-speed data transmission.

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