Back Reflection Images courtesy of Atlantic-Cable.com
The Optical Era Japanese Submarine Cables Part 3 Japan consists of four large islands, Honshu, the main land, Hokkaido, Kyushu and Shikoku along with around 4,000 smaller islands. Because of this, submarine cables play an important role in Japan’s domestic telecommunication infrastructure. Therefore, it was not surprising that Japan became the first country in the world to implement submarine fibre technology commercially. By connecting optical fibre submarine cables to optical fibre land cables, it quickly built up a backbone network which stretched 4,500km from Asahikawa in Hokkaido to Okinawa in the South. The first commercial, repeatered, optical submarine system deployed anywhere in the world was a Japanese domestic system owned by NTT. FS-400M was 300km long and was laid in 1986 by Kuroshio Maru between Hachinohe and Tomakomai, thus connecting Honshu and Hokkaido. The OCC supplied cable contained 6 single mode fibres and the system contained 7 NEC Repeaters; operating at 1,310nm, 400Mb/s; 445.837mB and a Line Code 10B1C RZ. The PFE was double end feed @ 1.8A.
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The first international repeatered system involving Japanese technology was TPC – 3, which was installed in 1988 and went into service in 1989. Segments AC and BC of the system were supplied
by Stewart Ash & Kaori Shikinaka
by Japanese companies, they included OCC cable containing 6 single mode fibres (Seg AC 2,220km; Seg BC 1,531km) as well as Fujitsu and NEC repeaters, operating at 1,310nm, 280Mb/s with a Line Code 24B1F.
factured equipment for these segments comprised OCC cable, repeaters of Fujitsu and NEC, and a number of Mitsubishi repeater amplifier units in OCC housings; the terminal equipment was supplied by Fujitsu, NEC and Toshiba.
In 1992, repeater development in Japan moved from regenerating technology to optical amplification. Deep (6,000m) water sea trials of the new repeater designs were carried out before they went into full production. The first optical amplified submarine system to go into commercial service, anywhere in the world, was a 900km domestic linking Kagoshima in Kyushu with Okinawa. This system owned by NTT, commenced manufacture in 1994 and was completed in 1995.
By the mid 1990’s Japan was a leading supplier of submarine optical fibre technology, a position it has maintained through the development of 10Gbit/s line rates, WDM and DWDM technologies up to the present day. This was further demonstrated at SubOptic 2010 by presentations on the emerging 40Gbit/s and 100GBits/s coherent technology. Clearly, Japan has been a major pioneer in the development of fibre optic submarine cable systems and remains a major influence in the development of our industry today. Fujitsu and NEC, along with OCC, remain among the world’s leading suppliers of submarine systems; KDDI and the NTT group are unquestionably influential system operators, and KCS and NTT WEM are leading marine service providers. In addition, our industry has benefited greatly from the technological innovation and products provided by such companies as Fujikura, Furukawa, Hitachi and Sumitomo. One hundred and forty years on from its first exposure to submarine cables, Japan is critical to the future of the submarine cable industry.
The first international optical amplified system in the world was the long haul system TPC-5 and the Japanese industry played a significant part in its construction. TPC-5 is a ring system connecting Japan, North America, Hawaii and Guam. The laying operation commenced in November 1993 with the landing of the cable in Ninomiya Japan. The total system length was some 24,500km and the final splice was not completed until August 1996. KDDI-SCS laid Segments T2 (Ninomiya – Miyazaki), Segment I (Miyazaki – Guam) and part of Segment J (Ninomiya - Bandon), a total of 5,900km. These were completed in October 1994, February 1995 and May 1996 respectively. The Japanese manu-