Nippon Telegraph and Telephone Corporation and NTT Communications Corporation have conducted 100 and 40Gbps transmission tests in real field environments using existing installed optical fiber, and have demonstrated for the first time, plug-and-play functionality that greatly reduces the setup time previously required for configuring optical signals. This was achieved using a new technology developed by NTT which is able to auto-configure 100 and 40 Gbps ultra-high-speed signals.
This research result enables 100 and 40 Gbps ultra-high-speed signals to be configured easily and automatically, similarly to the 1 Gbps-class signals used for fiber-to-the-home (FTTH). It has been difficult to configure such signals immediately till now. This type of ultra-high-speed plug-and-play functionality, operating in 50 ms or less, will simplify network operations and maintenance and dramatically improve the speed of optical signal recovery when faults occur.
In cooperation with NTT, NTT Com tested DSP circuit performance in this way for all manner of transmission environments, devised a procedure to verify the response characteristics, and built a field-test system spanning 580 km (with average transmission path polarization mode dispersion*7 of 35.5 ps) using its own installed commercial fiber.
To study the state of optical signal communication, 11 wavelengths with 100 or 40 Gbps signals per wavelength were transmitted under over 1000 different artificially-created transmission conditions, in field tests spanning 580 km. The results confirmed extremely stable automatic configuration in all cases. Simulating various conditions provided evidence that the technology would be able to maintain the quality of the main signal under all conditions of installed fiber throughout Japan. Also, by measuring DSP configuration times, we confirmed that automatic configuration in 50 ms or less (excluding optical fiber propagation delay) was achieved, verifying DSP performance as designed in real operating environments.