Infinera and subsea cable operator Seaborn Networks have completed a subsea field trial demonstrating what they say is the industry’s highest spectral efficiency on an ultra-long-haul subsea cable.
The 8QAM trial demonstrated 4.5 bits per second per hertz on the Seabras-1 cable with a distance of more than 10,500 km, enabling up to 50% more capacity than systems without advanced coherent technologies such as Nyquist sub-carriers and SD-FEC gainsharing.
“This is an impressive achievement that far surpasses what we expected,” said Larry W. Schwartz, chairman and CEO of Seaborn Networks.
Infinera said the demo also showcased the performance of its Infinera XTS-3300 meshponder featuring the Advanced Coherent Toolkit (ACT).
The XTS-3300 is based on Infinera’s Infinite Capacity Engine 4 (ICE4) and is optimized for long- haul subsea applications. The performance of ICE4 technology incorporates technologies to boost capacity-reach performance including digitally synthesized Nyquist subcarriers, enhanced pre- and post-dispersion compensation, improved non-linear tolerance and SD-FEC gain sharing, which Infinera says is only possible with its dual-channel DSPs. These capabilities collectively support up to 18.2 Tbps per fiber for distances over 10,000 km.