With the development of science and technology, Wi Fi wireless Internet technology has brought us convenient and efficient network experience. In contrast, Li fi technology is rarely known, so what kind of technology is it? < p > < p > Li FI is visible light wireless communication, also known as optical Fidelity Technology. It is a kind of technology that uses light emitted by light bulb to transmit data. It is to implant a tiny chip into the LED bulb to form a device similar to WiFi hotspot, which is convenient for terminal equipment to connect to the network at any time. < / P > < p > it sounds like magic to surf the Internet with light, but the basic principle of Li fi technology is not complicated. “0” and “1” are the most basic signals in digital transmission. If the light off state is set to “0” and the open state is set to “1”, the digital signal transmission can be realized through the light off and on. Therefore, lighting equipment must withstand high frequency switch. The traditional incandescent lamp can affect its life, and its response time is millisecond. While the LED lamp can withstand high frequency switching, the response time is still nanosecond. Therefore, LED provides a technical basis for Li fi. < / P > < p > the chip embedded in the LED bulb will make the light flash at a high speed, and the human eye can not detect this high frequency of light and dark changes, so it does not affect the lighting effect. For the photosensitive sensor, it can detect the high-frequency light and dark changes, so Li FI is compatible with the data transmission function and lighting function of light. < p > < p > although the data transmission of Li fi bulb can only be carried out when it is turned on, the brightness of the bulb can be dimmed to the extent that the human eye can’t recognize it without lighting, so the data transmission can still be carried out. Li fi uses visible light, so its penetration is insufficient. However, this feature happens to be an advantage in some cases. Its network connection has better privacy, which can make hackers unable to connect outside the range of the transmitter, and its security is better than Wi Fi. < / P > < p > in addition, Li fi enables larger broadband and higher speeds than Wi Fi, and its network settings require almost no new infrastructure. The advantages of Li fi lie in that it is not interfered by radio waves, has many resources, and is energy-saving and environmental protection. The development potential of Li FI is obvious, and its application fields are very wide, including indoor network, sensor network, intelligent traffic lights and medical treatment. It can be applied to multiple intelligent scenes, such as in smart home, Li FI can be applied to intelligent lighting hardware such as ceiling lamp; it can also be applied to wearable devices with integrated LED, real-time monitoring of human health parameters, and synchronous transmission of data to the Internet. < / P > < p > in general, Li FI can be said to achieve wireless networks where there are lights. With the two-way cooperation with Wi Fi, the realization mode of wireless data transmission will become more perfect, safe and efficient, and lead a new intelligent life.