Li-Fi is an emerging wireless internet connection technology. Light Fidelity, abbreviated as Li-Fi, uses the visible light spectrum, not Wi-Fi radio waves, to transmit data. Li-Fi, which can provide internet access a hundred times faster than Wi-Fi, transmits data electromagnetically. Invented by Professor Harald Haas from Edinburgh University in Scotland, the Li-Fi system requires an internet connection, a chip light source and a photo detector to work. Considered more reliable than a cellular or Wi-Fi connection due to its unique features and seamless connectivity, Li-Fi can theoretically provide access speeds of up to 224 Gbps according to laboratory tests.
What is Li-Fi and How Does It Work?
The short answer to the question of what is Li-Fi, which uses light emitting diodes for data transmission, is that it is a visible light communication system. Li-Fi, the only form of VLC that allows bidirectional transmission of light, uses the visible light spectrum via LED bulbs equipped with a special chip, instead of radio frequency. It needs a photodiode and a chip light source as a system component. The photodiode acts as a transceiver that receives and transmits light signals back.
Li-Fi systems use a strong, solid light source, such as an LED bulb, to send data over light. LEDs differ from halogen or filament bulbs because of their heat-free operating principle. Semiconductor LED bulbs can emit light in accordance with the current flowing through them, as well as starting to work quickly. LED bulbs, which act as light-emitting diodes, are equipped with a chip that serves as the signal processing unit.
In Li-Fi connection, the current supplied to the semiconductor LED bulb is modulated and transformed into a signal. This change takes place at extremely high speeds that the human eye cannot detect. The transmitted signal is received by a photodiode, which interprets changes in light intensity as data. The photodiode converts the data it receives through the Li-Fi bulb into a binary data stream that humans can perceive, such as video and audio applications. It distributes the internet to the user’s electronic devices such as computers and tablets. As with Wi-Fi, it can create a network through a Li-Fi modem and internet service provider.
Unlike radio waves, Li-Fi makes use of the visible light spectrum, which is in the middle of the light spectrum and can be perceived by the human eye. Because the visible light spectrum is ten thousand times larger than the radio spectrum, it enables the Li-Fi connection to access a wide useful frequency range. The visible light spectrum covers colors from the near ultraviolet to the near infrared, with frequencies between 430,000 and 770,000 Gigahertz.
What are the Differences Between Li-Fi and Wi-Fi?
Li-Fi and Wi-Fi connection differences can be listed as follows:
- Definition: Li-Fi stands for Light Fidelity, Wi-Fi stands for Wireless Fidelity.
- Operation: Li-Fi transmits data with light with the help of LED bulbs, and Wi-Fi transmits data via radio waves with routers called Wi-Fi routers.
- Interference: In Li-Fi connection, connection problems similar to radio frequency waves are not experienced. Connection problems occur on Wi-Fi from nearby access points.
- Technology: Li-Fi, IrDA compatible; Wi-Fi uses device technology that complies with the WLAN 802.11a/b/g/n/ac/ad standard.
- Applications: Li-Fi is used for data transfer or internet browsing in airlines, submarine research and operating theatres. Wi-Fi is used to surf the internet with the help of connection kiosks or hotspots.
- Advantages: Li-Fi technology causes less interference. Li-Fi can pass through sea water, work in dense areas. Wi-Fi has more connectivity issues, cannot cross sea water and can work in low-density areas.
- Privacy: With Li-Fi, a much safer data transfer is provided as light cannot pass through walls. With Wi-Fi, extra techniques are required to ensure secure data transfer, as the RF signal can pass through walls.
- Data transfer rate: Li-Fi data transfer rate reaches about 1 Gbps. Wi-Fi, WLAN-11n provides 150 Mbps speed. Wi-Fi can achieve data transfer rates of about 1-2 Gbps using WiGig/Giga-IR.
- Frequency: Li-Fi has ten thousand times the frequency spectrum above radio; Wi-Fi has frequencies of 2.4GHz, 4.9GHz and 5GHz.
- Coverage: The coverage distance of the Li-Fi connection is about ten meters. Wi-Fi has a range of approximately thirty-two meters, although it varies according to transmission power and antenna type.
- System components: An LED bulb with a chip and a photo detector are sufficient to establish a Li-Fi connection. Wi-Fi requires the installation of routers, modems and access points.
Instead of choosing one of the Wi-Fi and Li-Fi connections; It may be more accurate to see the Li-Fi system as a complementary technology that relaxes the dense radio spectrum to improve the performance of the existing technology.
