A novel transfer technology for video data has been developed by the researchers at Heinrich Hertz Institute (HHI) based in Berlin, Germany.
Novel Method Allows Data Transfer by Light
The scientists had represented the outcomes of the project that comes under the OMEGA project of the EU in Rennes, France in May 2011. During the demonstration, they used LEDs in the ceiling that cover up over 10 m2 to transfer data at a speed of 100 Mbit/s. The receiver can be positioned anywhere inside this radius. HHI’s Anagnostis Paraskevopoulos said that this allowed the transfer of four HD-quality videos to four laptops concurrently. HHI in partnership with France Telecom Orange Labs and Siemens developed the basics of visible light communication (VLC), he added.
Paraskevopoulos further said that the light source used for VLC was white-light LEDs that light up the room as well as transfer data. The researchers used a special component called the modulator to turn on and off the LEDs in quick succession in order to transfer the data as zeroes and ones, he added. The fluctuation of the light is invisible to the human eye. An ordinary photo diode placed on the laptop could function as a receiver.
Klaus-Dieter Langer, who is the project manager at HHI, is now involved in the improvement of the new technology. Langer stated that the diode captures the light and the data is decoded by electronics and then transformed into electrical impulses. The researchers stated that VLC is not designed to substitute standard UMTS, PowerLAN or WLAN. However, it can be used in data transfer applications that cannot use radio transmission networks. VLC can also be coupled with PowerLAN for the use of a return channel and with optical WLAN in one direction channel. At present, the researchers are involved in the development of systems with higher bit rates. Langer stated that in the lab, a transfer rate of 800 Mbit/s was made possible by utilizing red-blue-green-white light LEDs and is a world record value for the VLC method.