Data transmission was carried out in the previously unused E-band
Scientists have achieved a revolutionary breakthrough in fiber optic data transmission, setting a new transmission speed record. Researchers have achieved data transfer speeds 1.2 million times faster than the average broadband line by tapping into previously untapped data bandwidth.
The experiment achieved a speed of 301 terabits per second, which is equivalent to transmitting 1,800 4K movies in one second. This is several times faster than the average fixed broadband speed in the US, which is 242.38 megabits per second, according to Speed ??Test.
The main way to achieve such high speeds was through the use of infrared light, which is transmitted through tubular glass strands, characteristic of fiber optic broadband. In addition, engineers tapped into a spectral range that had never before been used in commercial systems, known as the E-band. For this they developed special devices.
The results of a study using fiber optic cables already installed in the ground have been published by the Institution of Engineering and Technology (IET). The team also presented their research at the European Optical Communications Conference (ECOC) in Glasgow in October 2023, but it was not made public.
Typically, commercial fiber optic connections transmit data through cables in the C-band and L-band infrared bands. The region used for Internet connections covers the range from 1260 to 1675 nanometers (visible light occupies wavelengths of approximately 400 to 700 nanometers in the spectrum).
However, as the volume of traffic increases, there is a risk of overloading these bands, which requires the use of additional transmission bands. The E-band, which is adjacent to the C-band, turns out to be an important resource. E-band was not generally used due to data loss in this region being approximately five times the data loss rate of C-band and L-band. C-band and L-band, which are between 1530 and 1625 nanometers, are commonly used in commercial compounds because they are the most stable.
The S-band, which is adjacent to the C-band and occupies the range from 1460 to 1530 nanometers, has been used commercially in combination with the other two in the «Wavelength Division Multiplexing» (WDM), which uses all three lanes to achieve much higher speeds.
However, it has not been possible to simulate E-band connections before because data loss in this region reaches extremely high levels — approximately five times the transmission loss rate in the C-band and L-band regions. In particular, fiber optic cables are sensitive to hydroxyl molecules, which can penetrate the tubes and disrupt connections, either during the manufacturing process or naturally in the environment. The E-band is called the «water peak» band because the extremely high transmission loss is caused by the absorption of hydroxyl molecules by infrared light in this region.
The new research created a system that made stable E-band transmission possible. Successful and stable data transmission at high speeds has been demonstrated using both the E-band and the adjacent S-band.
To maintain stable communications in this area, the researchers created two devices — «optical amplifier» and «optical equalizer». The first helps to amplify the signal at a distance, while the second monitors each channel and adjusts the amplitude if necessary. The researchers placed them in fiber optic cables.
While the 301 Tbps data rate is impressive, other researchers have also demonstrated high speeds using fiber optic connections in recent years. For example, in November 2023, a team from the National Institute of Information and Communications Technology (NICT) set a world record for data transfer speeds, reaching 22.9 petabits per second. That's about 75 times faster than the speed achieved by the team in this study. In their experiment, they used WDM (wavelength division multiplexing) technology, but did not have access to the use of E-band wavelengths. High-speed connection has been demonstrated over a distance of 13 kilometers.
These advances highlight advances in fiber optic connectivity and continue to open up new possibilities for data transmission. Future research will focus on developing techniques and technologies to achieve even higher data rates and improve the stability and efficiency of fiber optic networks.