NTT: optimization approach has more than doubled capacity of submarine cable system
Japan's NTT Communications Corporation (NTT Com) reports that a system refinement has enabled it to deploy 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.
A press release said that NTT Com demonstrated 100 Gbps optical transmission using digital coherent technology on the company's 21,000-km long U.S.–Japan route in October 2011, but that it initially was difficult to provide stable 100 Gbps communication over long distances due to the characteristics of light. The digital coherent technology, it said, improves spectral efficiency through multi-level modulation, such as phase modulation and polarization multiplexing, greatly enhancing receiver sensitivity by combining coherent detection and digital signal processing.
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," the release said.
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, the release said. It noted that 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.