Orange and Nokia have achieved what they claim is a new optical transmission record for 250Gb/s per wavelength, sending a 1.5Tb/s super-channel over a distance of 870km across Orange Poland's existing network infrastructure.
These results represent a 250 per cent increase in capacity per wavelength compared to mainstream 100Gb/s optical systems, using the same amount of spectrum while also gaining a 70 per cent distance improvement over comparable field trials.
The Nokia optical equipment used in the trials is commercially available now, and demonstrates how operators like Orange Poland can stay ahead of surging bandwidth demand in a cost effective manner using this technology, the vendor points out.
Optical systems typically achieve maximum transmission capacity over short distances and lower capacity across long distances. This trial demonstrated how capacity and distance can be improved simultaneously, using Nokia technology.
The 1.5Tb/s super-channel is based on six carriers of 250Gb/s capacity each occupying a bandwidth of 300GHz. This was transmitted 870km between Warsaw and Wroclaw over standard singlemode fibre with standard erbium-doped fibre amplification applied to 20dB spans.
With electrical speed (baud rate) only 30 per cent faster than current technology, the capacity is maximised while the channel spacing remains aligned with the 50 GHz ITU-T grid. This keeps the spacing between channels as existing 100Gb/s systems, which will ease network planning and operation, Nokia notes.
Orange and Nokia also demonstrated with a real-time transponder a record spectral efficiency of 5b/s/Hz using 250Gb/s carriers on the 50GHz grid with 16QAM modulation.
If all 96 channels that could be provided by the optical system were lit up and amplified, then then new optical link could transmit up to 24Tb/s of traffic in total, according to Nokia.
Christian Gacon, vice president in charge of Orange's transport networks, said: ‘This ground-breaking milestone will be the basis for faster networks and a better user experience for our customers. Bandwidth demands are continuing to skyrocket, but we also need to keep our infrastructure costs in check. Reaching these new heights in optical transmission proves we can meet bandwidth demand while maintaining the lowest cost per bit so our business can continue to flourish.’
