VLC is both safe and economical
Starting from last year, Science and Technology Commission of Shanghai has distributed this international leading wireless communication technology in colleges and universities and scientific research institutions within the whole city. The research and application of key visible light communication technology undertook by Fudan University made remarkable progress: Not only can the researchers transmitting network signal by visible light, but also realized to make 4 computers get online transmit signal by lighting a light. Professor Chinan, one of the researches pointed out that the same with radio wave, the light is a kind of electromagnetic wave and the basic principle of network signal transmission is the same. During the research, to put microchip in an ordinary LED bulb can controlto millions times flicker of every second. It represents 1when it is on while 0 when it is off. Because of the high frequency, it cannot sensed by human eyes but photosensitive sensor can sense the change, thus the binary data was soon effectively transmitted and coded into light signal. The computers under the light can understand Morse code in the light by a special receiving device.
Where there is light, there is network signal. There is no network when the light is off. Chinan told the journalist that compared to the existing WIFI, the future VLC is both safe and economical. WIFI relies on the transmittion of wireless radio wave and the regional electromagnetic radiation grows stronger as the power of the device becomes larger. The web information is unsafe as the wireless signal transmitting through the wall. The potential safety hazard will disappear in visible light communication. Moreover, the spectrum is 10000 times bigger than wireless frequency which signifies broader broadband and higher speed and almost no new infrastructure in network setting.
Limitations of Lifi technology
Certainly, as a brand-new network technology and product still in the laboratory, its potential should not be over exaggerated. “Because the series of key technology products from light communication control to chip design and production were all completed by researchers. There is still a long way to go before entering thousands of households and goes through a series of industrial development.” Chinan thinks that Lifi itself has the limitations like the network signal will be cut down if the light is blocked and so on. Therefore, it is not an opponent of WIFI but a supplement and is conducive to release spectrum space. It depends on people’s infinite imagination if it will be widely used in the future. To communicate between cars by LED car light and surf the Internet by the LED reading lamp over the head in the passenger cabins in the airplane.