NEC shows off 50Tb transmission over 10,000km subsea cable

12 May 2017 | James Pearce

NEC has demonstrated 50Tb transmission capacity over a 10,000km subsea cable in what it claims is an industry first.

The Japanese carrier used C+L band erbium-doped fibre amplifiers (EDFA) to achieve the high capacity over a long distance, as it looks o push the benchmark to trans-pacific distances.

NEC said the test required the efficient use of bandwidth at a level close to the Shannon limit, the spectral efficiency limit of optical communications.

The trial saw NEC researchers developing a multilevel, linear and nonlinear constellation optimisation algorithm as they sought to demonstrate consistency near to the Shannon limit.

C+L amplification can also maximise the capacity per fibre pair, allowing NEC to set a new record breaking capacity distance product of 570 petabit per second kilometre.