Infinera, provider of Intelligent Transport Networks, announced the successful completion of a series of record-breaking submarine field trials over MAREA, a 6,600-kilometer (km) submarine cable between Virginia Beach, Virginia and Bilbao, Spain.
The trials used Infinera’s fourth-generation Infinite Capacity Engine (ICE4) advanced coherent technology to achieve new records for trans-Atlantic real-time spectral efficiency:
- 6.21 bits per second per hertz (b/s/Hz) over 6,644 km, translating to a fiber capacity of 26.2 terabits per second (Tb/s).
- 4.46 b/s/Hz over 13,210 km for 18.6 Tb/s fiber capacity.
To achieve the record-breaking results, Infinera employed several advanced technologies including precision, multi-carrier common wavelocking based on Infinera’s large-scale photonic integrated circuit (PIC), digitally synthesized subcarriers with “near Nyquist” pulse shaping, enabled by the ICE4 real-time coherent digital signal processor, and operation over a high-optical power, large-area optical fiber cable.
Bandwidth-hungry applications and cloud-scale architectures are driving the need for dramatically increased subsea network capacity. Meeting these demands requires a combination of a cutting-edge optical wet plant and real-time advanced coherent transmission systems. Historically, trans-Atlantic cables have not been able to use higher order modulations, such as 16 quadrature amplitude modulation (16QAM), to achieve higher capacity. Several technology advances helped overcome this limitation. These include modern, large effective area subsea cables that improve the reach for higher order modulations. Combining this with a range of advanced coherent technologies and unique properties of a PIC implementation, Infinera successfully validated 16QAM over unusually long distances, using exceptionally tight channel spacing.