319 terabits – great Scott! Boffins in Japan speed along information superhighway at new world record

System compatible with existing infra. No you can't eat it now, kids, it's for later, for upcoming 5G backbone

Japanese researchers have broken the world record for the fastest internet speed by transmitting data at 319 terabits per second (Tbps) using modern day compatible fibre optical cable, according to the country's primary comms research institute.

The 3,001km (1,864 miles) optical fibre was designed by engineers at the National Institute of Information and Communications Technology (NICT) Network Research Institute.

The boffins used 4 cores within the fibre to transmit the data, and applied wavelength-division multiplexing (WDM), allowing multiple wavelengths to be sent simultaneously over a single strand of fibre. The individual WDM channels, numbering 552 in this case, were then modulated to form multiple signal sequences at alternate intervals.

The team employed a band that has never before been used for long distance transmissions, the S-band (1,460-1,530nm), alongside the usual C and L-bands.

Every 70km of the experimental set-up, the signal was subjected to amplifiers doped with rare earth ions, some with thulium, others with erbium. The boffins also used Raman amplification distributed along the transmission fibre itself to boost the signal.

The researchers said the system was compatible with modern-day infrastructure and shouldn't take long to adopt because the fibre still has a standard outer diameter of 0.125mm.

But while it may look like your normal fibre from the outside, the transmission rate is 79 per cent faster than the previous world record set at University College London (UCL) in August 2020 with a data transmission rate of 178Tbps.

While these fibres won't be making it into homes any time soon, they'll likely benefit the wider networking structure.

In their canned statement, NICT said:

[It] is hoped that such fibers can enable practical high data-rate transmission in the near-term, contributing to the realization of the backbone communications system, necessary for the spread of new communication services Beyond 5G.

The results of this experiment were published at the International Conference on Optical Fiber Communication in June and announced in English this week. ®