Like the idea downloading the contents of a DVD in less then 10 seconds without a cable in sight? That’s exactly what a team of German engineers can do, having broken the record for wireless data transmission using terrestrial radio signals.
A team of researchers from the Fraunhofer Institute for Applied Solid State Physics claims to have beaten the previous record for beaming data in this way by a factor of 10. To achieve the feat, they transmitted data on signals in the 71–76 GHz radio frequency band, which is usually used for terrestrial and satellite broadcasting.
But to squeeze in that amount of data requires an impressive signal-to-noise ratio, to avoid having to waste bandwidth on error-correction. So the team built a system of ultra-efficient transmitters and receivers. The transmitters are based on semiconductor chips made gallium-nitride, which provide a high-power signal that’s transmitted from a focused parabolic antenna.
The team beamed the signals between a 45-storey tower in central Cologne and the Space Observation Radar in Wachtberg, 23 miles away. At the receiver, the researchers used special low-noise amplifiers built using indium-gallium-arsenide transistors. Their sensitivity allows them to detect incredibly weak signals.
The resulting speed of 6 gigabits per second has pretty obvious application. The researchers points out that a single transmission beam could be used to supply as many as 250 internet connections running at 24 meagabits per second to sites where it’s impossible to run a wired connection. While you might immediately think such a system would be best suited to, say, disaster zones, the researchers reckon it could even prove a “cost-effective replacement for deployment of optical fibre”. Watch this space. [Fraunhofer Institute for Applied Solid State Physics]