NTT to deploy Fujitsu 100-Gbps DWDM systems to connect Tokyo and Osaka/Broadband Forum: Broadband reaches 600 million subscribers worldwide

Fujitsu says it has collaborated with NTT Communications Corp. on a successful field test of coherent 100-Gbps DWDM transmission via a commercial fiber-optic cable between Tokyo and Osaka. The test clears the way for full network construction using the 100-Gbps DWDM systems.

While Fujitsu has implemented coherent 100-Gbps DWDM systems outside of Japan (see, for example, “Mid-Atlantic Crossroads uses Fujitsu FLASHWAVE 9500 for 100-Gbps network”), the field test opens the door for its first deployment in Japan. The test was conducted using dispersion-shifted fiber in the L-Band, which is often used in Japan for long-haul transmissions.

The field test simulated real-world situations, such as fiber-optic cable changes in accordance with transmission-circuit route changes and adding/removing wavelengths. The results confirmed that a quality sufficient for commercial operation could be achieved at 8 Tbps (100 Gbps x 80 multiplexed wavelengths). The test also demonstrated that the system could compensate automatically when adding chromatic dispersion and polarization mode dispersion to actual transmission circuits.

Digital coherent transmission technology makes use of results achieved in two previous research projects, “R&D on High-speed Optical Transport System Technologies” and “R&D on High-speed Edge Node Technologies,” which were supported by the Ministry of Internal Affairs and Communications.

According to the Broadband Forum and analyst firm Point Topic, service providers worldwide added more than 16 million broadband subscribers during the first quarter of this year. The additions brought the total number of broadband subscribers worldwide to more than 600 million.

“This is another significant milestone in an exciting arena that shows no sign of slowing down,” commented Robin Mersh, CEO of the Broadband Forum at the recent CommunicAsia event in Singapore. “It is just 18 months since we celebrated the 500 million subscriber watershed and even less time since IPTV subscribers reached 50 million — yet in both cases growth is still accelerating. It is especially rewarding to be making this announcement in Asia, which has contributed so much to fuelling this phenomenal success. I am also particularly pleased to see how exceptionally well fiber is doing, a clear indication of the importance of our continued efforts in testing and certification of G-PON.”

While DSL remains the most heavily used broadband technology – at 369,898,515, it accounts for more than half of current broadband subscriber lines – fiber-based technologies grew most strongly, the Broadband Forum and Point Topic report. FTTx subscribers grew 32.21% year over year, while FTTH line totals increased by 24.03% over the same period. DSL grew 7.52% while cable modem lines (the second most popular access technology) grew 8.48%.

Still, FTTx and FTTH have a ways to go before they threaten DSL’s position, or even cable modem’s. FTTx lines stood at 87,732,35 by the end of the quarter, with FTTH lines at 16,519,984.

“DSL is the most popular access technology on a global basis: Although its market share has dropped by 0.5% in the quarter, there is a long way to go before the copper-based access technology is overtaken,” confirmed Oliver Johnson, CEO of Point Topic. “For fiber, the cost-effectiveness, from the operators point of view, and the significant increase in bandwidth over DSL in particular is hitting the sweet spot at the moment in terms of technology market share.”