In this blog post, we will explore why Li-Fi, a high-speed wireless communication technology that uses light, is attracting attention as the next generation of innovative technology.

Data transmission using visible light

Li-Fi is attracting attention as the next generation of communication technology, and it transmits data through an innovative approach that is different from existing communication methods. In particular, it is differentiated by using visible light. Visible light is light that can be seen by the human eye, but the fact that it can be used as a means of communication is a new concept to many people. This innovation is possible thanks to the development of science and technology, and the high bandwidth of the frequencies of visible light has opened up the technical possibility of transmitting more data at once.
In recent years, we have seen the evolution of Long Term Evolution (LTE) technology to Long Term Evolution Advanced (LTE-A). LTE-A provides three times the speed of existing LTE, which represents a significant improvement in communication speed. All three major telecommunications companies in Korea (SK Telecom, KT, and LG Uplus) are offering broadband LTE-A services. However, as communication technology advances, the amount of data used by users is also increasing rapidly. In particular, new services require even more data, which is exacerbating traffic problems. So, how can we handle the explosive increase in traffic? Li-Fi may be the answer.
In Li-Fi, “Li” stands for light and “Fi” for fidelity, and this technology was proposed by Professor Harald Hass of the University of Edinburgh in the UK. Professor Hass devised a method of transmitting data using the light from LED bulbs, and the principle is very simple. LED bulbs can flash more than 200 times per second, and this flashing speed is used to transmit the 1s and 0s of data. For example, data is sent and received in a way that means 1 when the bulb is turned on and 0 when it is turned off. This principle is very efficient and opens up the possibility of transmitting data faster than with existing communication methods.

Why use visible light?

So why use visible light among all the electromagnetic waves? Visible light has several characteristics that make it suitable for Li-Fi. First, visible light can be detected by the human eye, but its rapid flashing speed is not perceived by the human eye. In other words, it can serve as the lighting we use in our daily lives while simultaneously performing the dual function of transmitting data.
Second, the frequency of visible light is very high, so it can transmit much more data at the same time than radio waves. The frequency band of visible light is more than 10,000 times wider than that of radio waves, so it can transmit large amounts of data at once by utilizing this wide bandwidth. In this respect, Li-Fi is much more efficient in terms of frequency resources than radio waves.
Third, visible light has a strong directivity. This means that it diffracts less (ability to pass through obstacles) than radio waves. In other words, it is difficult to send data through walls, but this characteristic can be a great advantage in terms of security. In other words, communication is impossible where light cannot reach, reducing the risk of hacking.

Advantages of Li-Fi

The first advantage of Li-Fi is that it can utilize existing infrastructure. Since the LED bulbs we already use are used as communication devices, communication becomes possible without additional equipment. In addition, existing communication equipment consumes a lot of energy to cool down, but Li-Fi can reduce this energy waste, so it is also attracting attention as an eco-friendly technology.
The second advantage is the increase in data transmission speed. Thanks to the wide bandwidth of visible light, more data can be transmitted at the same time, which is achieved through OFDM (orthogonal frequency-division multiplexing) technology. This technology can greatly increase traffic throughput because it can transmit data by dividing multiple frequencies. In particular, in the current situation where data usage is rapidly increasing, Li-Fi can be an important alternative to solve traffic problems.
In addition, the directness of visible light makes it highly secure. If the light is blocked, communication becomes impossible, reducing the risk of hacking, which is the illegal interception of communication from outside. This is a major difference in security compared to existing Wi-Fi, which uses radio waves.

Disadvantages of Li-Fi and Solutions

Of course, there are also disadvantages to Li-Fi. One of the biggest disadvantages is the difficulty of building infrastructure. This means that you will need to replace existing incandescent bulbs or LED bulbs that do not support Li-Fi with LED bulbs that support Li-Fi. This may be an expensive initial investment, but in the long run, the energy savings and speed improvements will make it cost-effective.
In addition, the directness of visible light can cause communication to be interrupted if light is blocked or there are obstacles. However, this problem can be solved by using a method that can be used in parallel with existing Wi-Fi. For example, if Li-Fi is used as the main means of communication, but Wi-Fi plays a secondary role in areas where light is blocked, communication can be maintained.

Conclusion: Potential as a future communication technology

Li-Fi has the potential to provide speeds that are theoretically ten times faster than existing communications. It is also an environmentally friendly and safe method of communication, and is expected to play an important role in the future communication infrastructure. If infrastructure improvements such as the government-led LED lighting distribution project are carried out in parallel, Li-Fi will soon become a common means of communication in our daily lives. Finally, I would like to quote Professor Hass and imagine a bright future for this technology.

“In the future, we will not only have 140 trillion light bulbs, but also 140 trillion Li-Fi networks installed around the world for a cleaner, more environmentally-oriented, and brighter future.”