High-speed Internet access without the need for WiFi light

High-speed Internet access without the need for WiFi light

No Wi-Fi signal is required. You can access the Internet by clicking an LED lamp. The School of Computer Science and Technology of Fudan University sent a message that an international cutting-edge communication technology that uses the visible light transmission network signal in the house was successfully implemented in the laboratory. The researchers connected the network signal to a 1 w led lamp, and the four computers under the light could access the Internet with a maximum rate of 3.25 GB and an average rate of 150 M, the world's fastest online lighting service ".

Visible Light communication is called Lifi

For a long time, a shining light bulb has been painted on the head of a person to represent the spirit of an inventor. But the German physicist Harold hashath, by the bulb itself, "lights up" the whimsy: relies on a small lamp to turn invisible network signals into "visible" network signals. Hashand his team at the University of Edinburgh recently invented a patented technology that uses flickering lights to transmit digital information, known as visible light communication (VLC ), it is often affectionately referred to as "Lifi", to show that it can bring revolutionary changes to the wireless network transmission technology represented by WiFi.

How far is this unimaginable network technology from us? The answer is: very close. It is coming to us step by step from the laboratory of Fudan University. Xue Xiangyang, a professor at the School of Computer Science and Technology of Fudan University, told reporters that the current radio signal transmission equipment has many limitations. They are rare, expensive, but inefficient, such as mobile phones, millions of base stations around the world help them increase their signals, but most of the energy is consumed by cooling, with an efficiency of only 5%. In contrast, bulbs used worldwide are inexhaustible, especially in China, which is replacing traditional incandescent bulbs in a large scale. Simply add a micro-chip to any humble LED bulb, you can turn the bulb into a wireless network transmitter.

Visible Light communication securityJi

Beginning last year, Shanghai Science and Technology Commission has deployed this cutting-edge wireless communication technology in universities and research institutes throughout the city. The research and application of key visible light communication technologies undertaken by Fudan University have made significant progress: researchers not only use visible light to transmit network signals in the lab environment, but also achieve "one-stop", that is, a small lamp is lit, and four computers can access the Internet and transmit network signals simultaneously. Professor Chi Nan pointed out that, just like radio waves, both belong to one type of electromagnetic waves, and the basic principles of transmitting network signals are the same. During the study, we installed a micro-chip on an ordinary LED bulb, which could be controlled to flash millions of times per second. If the light is 1, the light is 0. Because the frequency is too fast, the human eye cannot detect the changes, but the photosensitive sensor can receive these changes. In this way, binary data is quickly encoded into light signals for effective transmission. The computer under the light, through a set of special receiving device, reads the "Morse password" in the light ".

"Where there is a light, there is a network signal. Turn off the lights and the network is completely unavailable ." Chi Nan told reporters that, compared with the existing WiFi, the future visible light communication security is more economical. Wi-Fi relies on invisible radio waves for transmission. As the power of devices grows, local electromagnetic radiation is bound to increase. wireless signals pass through the wall, and network information is insecure. These security risks are swept away in visible light communication ". In addition, the spectrum is 10000 times larger than the radio spectrum, meaning greater bandwidth and higher speed, and there is almost no need for any new infrastructure for network settings.

Lifi technology also has its limitations

Of course, as a new network technology and product that is still in the laboratory, its future potential should not be overestimated. "Because, from lighting communication control to chip design and manufacturing, a series of key technical products are the work of researchers. To truly enter thousands of households like WiFi, a series of industrial development is required, there is still a long way to go." Chi Nan believes that Lifi technology also has its own limitations. For example, if the light is blocked, the network signal will be cut off. Therefore, it is not a competitor of Wi-Fi, but a complementary solution that helps to release spectrum space. In the future, whether it can produce killer applications depends on the infinite imagination of people: cars rely on LED lights to "talk", and passengers in the aircraft cabin use LED reading lights to access the Internet.