How to transmit 700 DVDs in just one second?
That’s probably not the exact question scientists at the Karlsruhe Institute of Technology posed themselves, but in a nutshell, that’s what they’ve accomplished recently in an experiment.
A team of scientists, led by Professor Jürg Leuthold, transmitted data at an unbelievable rate of 26 Terabits per second on a single laser beam, transmitting the data over a distance of 50 kilometers.
The secret behind this astounding feat is the way the data decoding process is handled. It revolves initially on purely optical calculation in order to break down the high data rate to smaller bit rates that can then be processed electrically. The initially optical reduction of the bit rates is needed, as there’s simply no electronic processing method available for such a high data rate. The team applies the so-called orthogonal frequency division multiplexing (OFDM) for record data encoding, a process that has been used successfully in mobile communications before, based on mathematical routines (Fast Fourier Transformation).
(Credit: Photo by Gabi Zachmann)
The added bonus of this initial and extremely fast calculation in the optical range is the energy-efficiency needed only for the laser.
Applications such as video conference consume much Internet bandwidth and require extremely high bit rates and this development would definitely be of massive interest. In comparison, today’s communication networks, utilize lines with channel data rates of 100 gigabits per second (corresponding to 0.1 terabit per second). Commercial research now concentrates on developing systems for transmission lines in the range of 400 Gigabits/s to 1 Terabit/s. With this new invention, we could leapfrog into the future.