Thursday, September 29, 2011

Streaming video with the power of LEDs

h/t – @carls8989

The same diode light that powered the wrist-calculator in 1980s classrooms is growing into something much more formidable. A Berlin research team is using the technology to stream HD video across a room. Michael Dumiak paid a visit.
Light-emitting diodes, or LEDs as they are commonly known, are small semiconductors that generate light when an electronic current is sent through a junction onboard the device.

Scientists have managed to make them more and more powerful in the past few months.

Researchers at the Heinrich Hertz Institute, part of the Munich-based Fraunhofer Institute for Telecommunications, have now managed to set up an array of LEDs in a panel that can light up a 10-square-metre room and transmit wireless data to laptops. It is, in essence, a kind of optical alternative to WIFI.

This optical networking works by modulating the LED panel very rapidly – turning it on and off faster than the human eye can see – which encodes data into a digital stream of ones and zeros. “We want to make clear that you can use off-the-shelf, normal white-light LED chips for data transmission,” says Anagnostis Paraskevopoulos, an intra-machine communication expert who has been working on the network.

Working with Siemens and the French Telecom Orange Lab, the team were able to stream lossless data at 100 megabits per second at a maximum range of ten metres.

Paraskevopoulos explains the idea is not to try to replace the standard microwave and radio WIFI routers found in your house or in more generous airports and hotels.

Instead, it would offer an alternative when such networks aren’t desired, as in a hospital, or don’t work. It may also be possible to create combinations and so-called mesh networks which extend the range and power of the light transmissions.             More