NTT Comms Deploys 100G Coherent on PC-1

TOKYO -- NTT Communications Corporation (NTT Com) announced today the world’s first deployment of 100 Gbps digital coherent technology on a transpacific submarine cable system linking the U.S. and Japan, increasing the design capacity of the company’s PC-1 system by more than 2.5 times to 8.4 terabits per second, effective immediately.

Data traffic has been growing rapidly due to the increased use of smartphones and tablets, music/video downloading, cloud computing and services such as social networking. In response, NTT Com demonstrated 100 Gbps optical transmission using digital coherent technology on the company’s U.S.–Japan route in October 2011. But despite the technology’s attractiveness as a method for rapidly expanding optical network capacity, it initially was difficult to provide stable 100 Gbps communication over long distances due to the characteristics of light. By optically optimizing the PC-1’s network architecture, including with strategically placed optical repeaters and an enhanced optical fiber layout, NTT Com has now achieved the world’s first commercial deployment of 100 Gbps digital coherent technology on a transpacific route.

By the end of 2014, 100 Gbps optical transmission technology also will be deployed in NTT Com’s Asia Submarine-cable Express (ASE), which links major cities in Asia via the shortest possible route for industry leading low latency.

PC-1 cable system
The PC-1 optical submarine cable, the shortest transpacific link, is operated by PC Landing Corp., an NTT Com group company.

Total length: 21,000 km
Configuration: Ring-topology network with landing stations in Japan and the United States
Landing stations: Ajigaura (Ibaraki Prefecture, near Tokyo); Shima (Mie Prefecture, near Osaka and Nagoya); Harbour Pointe, Washington; and Grover Beach, California

Digital Coherent
Digital coherent is the latest transmission technology that improves spectral efficiency through multi-level modulation, such as phase modulation and polarization multiplexing. It greatly enhances receiver sensitivity by combining coherent detection and digital signal processing.

NTT Communications Corp.