The project is a collaboration between several German institutions. Dubbed ACCESS, short for Advanced E Band Satellite Link Studies, the team used radio frequencies that are typically populated by terrestrial broadcasters to obtain the record transfer rate.
The broadcasting towers were set up in the city of Cologne and the town of Wachtberg, 36.7km away. Data was then wirelessly transmitted over the connection using radio waves in the 71-76GHz frequency range.
The results were phenomenal, achieving 6 Gigabit speeds. In comparison, services often marketed as “superfast” broadband are usually around 50 Megabit, with some providers offering 100 Megabit. In select urban regions, 1 Gigabit speeds can be obtained.
6 Gigabits per second is sufficient to transfer the contents of an entire DVD in under ten seconds. The team estimated the bandwidth could be split up to provide 250 homes with 24Mb/s broadband, a rate typically viewed as a borderline between high-speed and super-fast.
The range over which the transfer was completed is equally impressive. The 37km (23 mile) gap between the base stations did not significantly impact speed. The system could be used to deliver high-speed Internet connections to remote regions in the future, becoming an alternative to optical fibre networks in areas that are difficult to reach.
The feat was achieved by employing the millimeter waves used by terrestial broadcasters. These waves are able to transfer enormous amounts of data but lose signal as the distance from the transmitter increases.
To overcome this, the project used efficient new transmitters and receivers called monolithically integrated millimeter wave circuits (MMICs). Manufactured by partner Fraunhofer IAF, the transmitters amplify the broadband signals to a high 1W power so they can travel longer distances. The receiver is equipped with special low-noise amplifiers that allow it to detect weak signals over a large distance.
“Transmitting the contents of a conventional DVD in under ten seconds by radio transmission is incredibly fast – and a new world record in wireless data transmission,” said Fraunhofer IAF. “With a data rate of 6 Gigabit per second over a distance of 37 kilometers, a collaborative project with the participation of researchers from the University of Stuttgart and the Fraunhofer Institute for Applied Solid State Physics IAF exceeded the state of the art by a factor of 10.”
There is still work to be done before the system can be deployed commercially. While it could be a cost-effective alternative to optical fibre, the radio frequencies used are currently regulated for commercial broadcasts. This could make it difficult to secure usage of the airwaves for broadband transmissions without interfering with terrestrial stations.
The ACCESS project ended on April 30 and has been superseded by ELIPSE, the E Band Link Platform and Test for Satellite Communication. ELIPSE will continue some of ACCESS’ work while exploring how to increase the connection speed with satellites. As it stands, the new world record for wireless data transmissions is a very respectable 6Gb/s. It still pales in comparison with the capabilities of optical fibres though, set earlier this year at an astounding 1.125Tb/s.