Wireless data transfer record smashed
By Ben Coxworth
January 25, 2010
If you’re like most people, you probably think that 200 megabits per second for wireless data transfer is just too darn slow! What are we, cavemen? Not anymore, apparently, as electronic engineering company Siemens just broke their own record by achieving 500 Mbps using white LED light.
Researchers from Siemens’ Corporate Technology sector in Munich successfully sent the data across five meters of empty space. They did it by modulating the power supply to an Ostar LED, made by Siemens subsidiary Osram. Although the resulting 500 light intensity fluctuations per second were invisible to the human eye, they were readable by a photodetector receiver, which converted them into electrical pulses. The researchers also established that a system combining five LED’s is capable of transmitting data over longer distances, at a rate of 100 Mbps.
This type of data transfer is known as Visible Light Communication, or VLC, and has many potential applications. It could be used in wireless local area networks, for instance, where traditional RF technology often results in data packet collisions due to crowded frequency bands - devices communicating with light wouldn’t have to bother seeking out and sharing radio frequencies. VLC would also be ideally-suited to settings such as hospitals, where radio transmissions are often limited or forbidden. In the field of transportation, LED signals or stoplights could relay information to vehicles like trains or transport trucks. And when it comes to highly-sensitive data, VLC would be a good choice because its signal can’t be tapped. Only the photoreceptor that is positioned directly in line with the LED’s beam can read the data.
The Institute of Electrical and Electronics Engineers has been working to standardize VLC activity, and will hopefully have done so by the end of the year.