Interpretation: visible light communication from the application of how far?

The driver of the House hearing, lights, mobile phone will be able to have the power to call and the Internet, it sounds cool, but this advanced technology has been in the laboratory environment occurred. For ordinary people, this project is long out of the lab? How can make changes in our life?

Dr. Shen Guobin Microsoft Asia Research Institute on visible light communication". He studied the earliest indoor positioning, 2012 began to study on visible light communication, indoor light is how to determine the position of people. Last year, he brought the team won the game world IPSN indoor location second.

What is the light transmission of information?

In early 2004, a IEEE journal paper explained by the light emitting diode (LED tube) provides a method of wireless network connection, the principle is this:

LED lamp is a semiconductor chip with traditional filament is not the same, the chip can fast switch, such as the use of alternating current light is 60 Hz, the human eye can recognize the light flashing. In a time of a closed, light is modulated by square wave, can transfer information, just like the phone in radio communication, we usually use the.

At present, many universities around the world have relevant research projects, most of them are carried out in the laboratory. In 2012, the communications industry magazine IEEE published an article that visible light transmission rate of 96Mbps paper.

By the end of 2013, can let the light a lamp power is 1W LED of the Fudan University in Shanghai led the lab, 4 computer under the light of the Internet, the highest rate of up to 3.25Gbps, the average net rate reached 150Mbps.

Microsoft Asia research earlier also do research in this area. The laboratory will try to light and the transmission rate of equipment at peak limit is not the same, want to study this possibility in conventional electronic devices, and his team at Taobao bought cheap LCD panel, a solar panel, a few dollars and you can test circuit board.

At present, Shen Guobin's team studied how to use the reverse reflector (Retro-Reflector), is actually a mirror, the light will be reflected back to the original road LED light, forming a mutual communication between LED and electronic equipment.

They've been able to do, under the switching frequency in the light of 1 megabytes, from lighting to downstream equipment speed reached 10kb/s, and the equipment from the reflective uplink speed reached 0.5kb/s.

In the Microsoft Asia Research and development center, we see this experiment with cheaper components made of: do not need to charge the line, there is no Wi-Fi signal, only one block with a LCD screen, mirror and solar panels similar mobile phone sized device. Light bulb LED flashlight, it lights up, and began to transmit data. The LED lamp has become a source of energy and information source of general equipment.

Intelligent traffic signs, no networking equipment need charging

Try to imagine, the lights of the roadside signs of such scenes, signs immediately to nearby vehicle navigator transmission Road, tell you arrive at the destination the most unobstructed road; the morning light, you can air detector will tell you that the outdoor air quality, temperature and humidity, and the tester display has been hanging in the bed, do not need to charge, also do not need to connect Wi-Fi or bluetooth.

Dr. Shen Guobin said, the intelligent signs, do not need to charge the networking equipment may be visible light communications they think of the future. It sounds beautiful, but still remain at the theoretical stage.

"We first thought is to discuss and product department to see this is not possible in the big Microsoft product blueprint to go inside, whether we design, or our ideas, as long as they can accept, we will be very happy."

But to achieve this in fact is not easy, need to launch LED lighting transformation is good, but also the need to introduce electronic products reverse transmitter at the same market sale. For a company, just from technology to products, need the team too much.

How far is the distance between research and products?

In 1880, a Canadian inventor Alexander Bell found an interesting play: change by adjusting the beam, transmission of voice signal, can both wireless dialogue - this is the first wireless telephone, is the use of visible light communication.

Baer for this invention patent application time, even the power did not appear, he also believes that the "telephone" without any practical value.

In fact, no matter what the scientific research project, in a product enterprise, product sector is still dominant. The product department has some problems to be solved, according to the development of technology is very fast and can be used on the products, and no related products, will be transformed into basic research products is very difficult.

In this case, the task is to research these cool technology through the paper or the internal Demo product departments to understand, hope they do product plans in the next will consider this technology." Shen Guobin said.

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