NEC and its subsidiary OCC Corporation have completed full qualification of subsea repeaters and optical cable containing up to 24 fiber pairs (FPs) (48 fibers). The new qualification is a 50% improvement in fiber count over the 16 fiber pair systems generally available today.
Only minor modifications were needed to NEC's existing repeater and cable designs. Keeping NEC's quadruple pump redundancy in the repeater (established more than 10 years ago) and maintaining OCC's outstanding cabling performance has resulted in cabled attenuations lower than 0.150dB/km. Low attenuation is critical to achieve large spectral efficiency as well as lower power consumption.
NEC said the qualification will allow for the construction of subsea telecom cables with superior traffic capacity while reducing the cost per bit of the wet plant. The development is fully in line with SDM (Space Division Multiplexing) system architectures.
"As global demands for capacity and FP flexibility continue to soar, NEC is committed to helping our customers to build up their subsea networks with large spectral efficiency, lower power consumption and large-scale subsea connectivity," said Yoshihisa Inada, Deputy General Manager and Head of Subsea Technology Development at NEC's Submarine Network Division. "We continue to evaluate multiple technical options to further increase capacity and reduce the cost/bit of the networks."
OCC's 24 fiber pair cable can be manufactured using a wide range of existing optical fibers, according to the needs of each new cable system. Each fiber can be visually identified using a field-proven combination of ring marking and conventional fiber coloring, first introduced in 2013. Furthermore, in OCC cable, the fiber's transmission performance is completely unaffected, either by the fiber marking or cabling processes.
"We have concluded that the use of our fibers in OCC's 24 pair cable results in a cabled attenuation matching the nominal value. We are confident that our ultra-low-loss fibers can contribute to achieve large capacity, high spectral efficiency and low power consumption in transoceanic networks," said Dr. Masashi Onishi, General Manager at Optical Fiber and Cable division of Sumitomo Electric Industries Ltd.
"To support growing bandwidth, next generation subsea systems will offer Petabit-scale transmission. To achieve the required performance, cabling processes must capture the advantaged optical attenuation and large effective area of our ultra-low-loss fibers. OCC's cabling process for 24 fiber pairs works with our high quality fiber to meet the challenge," said Dr. Bernhard Deutsch, VP & GM, Optical Fiber & Cable, Corning Incorporated.
NEC targets subsea cables to 24 fiber pairs and beyond
