As the light meters altitude Internet CAS successfully set up the "LED optical wireless network"

7 per night, 1 billion 30 million pieces of LED chip (semiconductor lighting) to "light", the Shanghai World Expo Park suddenly Ambilight, became possible demonstration of LED application show: indoor and outdoor lighting, landscape decoration, signage and display information......

LED's ability is just lighting? No At the moment, in a cabin in the simulation of World Expo airlines, the other a "subversive" Application of LED in the demo: no cable, no wireless card, in a soft blue light, your notebook computer can connect to the Internet, free communication, free talk.

With the light to replace the cable, while flying in the altitude of 10000 meters, while using a mobile phone or computer to capture the world, this is a surreal sci-fi plot, or soon after the scenes of life? Expo Park in Shanghai, the world's most concentrated LED technology application demonstration area, "everything starts with World Expo will probably add a classic case.

Frequent "eyes open", "closed eyes" to send signals

In the era of communication is not developed, flashlights have been used to communicate with each other, "the language of light". In the ubiquitous network in twenty-first Century, everywhere can see the lights of the cable, the transmission network signal? After years of painstaking research, Chinese Academy of Sciences Institute of semiconductor researchers successfully set up a set of LED optical wireless network, the maximum transmission rate of 2 megabits / sec.

Why is LED? Originally, the luminescence principle limit, incandescent lamp, fluorescent lamp and ordinary energy-saving lamp switch are a little sloppy, not simply, the switching frequency is not up to the requirement of high speed transmission; while LED revolutionized the way light predecessors ", can be extremely neatly" eyes "," close your eyes "send in the frequent" blink "signal, pass by" 0 "and" 1 "massive data.

Does the blinking of the switch affect normal lighting? The Chinese Academy of Sciences, Institute of semiconductor photoelectric system lab, Duan Jingyuan told reporters that at present, the LED light switch rate up to 4 million times per second, but when the lights flicker frequency is higher than 1000 times per second, the human eye can't feel. Interestingly, the lights in the transmission of the signal, do not have to completely close the eyes, just adjust the brightness can correspond to the "open" and "off":3/4 brightness on behalf of "open", 1/4 brightness represents "off"".

Of course, a lighting LED lamp does not own the "blink", the researchers designed a "small box" to control its flashing, computer USB socket is dragging a small tail, used to probe signal - a "box" and "tail" and "sing" computer network, and can accurately download and upload.

Internet access does not interfere with the sky and earth communications

World Expo Aviation Museum, there is a 6 square meters of lighting experience area. All the furnishings here are modeled on the real engine room, and the blue light LED reading light above the seat is a wireless access point on a laptop on a small table. Sitting in the seat, fasten the safety belt, the passengers who or browse web page, or micro-blog update, or online to see a New World Expo broadcast, this "flight Internet" was first experience.

Some people ask: if the plane is flying in the sky, I will not be asked "please turn off your cell phone and wireless Internet equipment"? "Duan Jingyuan," said the lamp, the light "router" is no electromagnetic waves, will not interfere with the aircraft's electronic equipment, communication can be carried out normally. Similarly, the light on the Internet for the hospital and other radio frequency sensitive areas.

Although the altitude of 10000 meters can not be laid broadband, access to our well-known metropolitan area network or WAN, but can borrow the top of the satellite communications network. In theory, it is possible that the Internet is a dream come true. However, paragraph Jingyuan, said the hospital may be the first application of LED optical wireless network. Because, the realization of the flight in the Internet, we must first of the aircraft on the transformation of the lighting equipment, and satellite communications equipment to establish an interface, more complex. "

"Light cable network" to be established standards

For home users, lighting, Internet two is correct and there is no electromagnetic radiation, is undoubtedly the novelty of lighting technology. However, in the same network speed, how many people will only be "light cable network" novelty and pay? Duan Jingyuan said, 2 Mbit / s only LED optical wireless network development progress, compared with the traditional wireless network, lights on the Internet have more bandwidth potential in theory, with high-definition video and other high bandwidth business has introduced, its speed advantage will grow with each passing day.

In addition to surfing the Internet, the LED wireless network there are a lot of refinement, such as intelligent transportation. In the future, the road on both sides of the LED street lights can be sent to the passing of traffic information at any time; two cars too close, then the lights each other "warning language", you can avoid collision or rub.

Duan Jingyuan said that all of these applications will also rely on the establishment and unification of standards. Currently, the United States, Japan and some European countries have been in the LED wireless communication technology research and development, and the formation of a protocol or standard alliance, domestic in this field is a slow shot". In the future, such as a standard, unified agreement, and hardware manufacturers to accept, in the "small box" and "small tail" will be in the form of chips integrated into the lamp and inside the computer, greatly reduce the cost of the system.