Lucent Scores NTT DWDM Deal and L-Band Amp Commitment
By: Erik Kreifeldt
Nippon Telegraph and Telephone Corp. (NTT, Tokyo) has selected Lucent Technologies (Murray Hill, NJ), among other vendors, to supply a dense wave division multiplexing (DWDM) system for NTT's core long distance network. The deal includes both Lucent's current DWDM system and plans to integrate a new L-band platform designed for dispersion-shifted fiber.
"This partnership reflects the beginning of the long-term strategic partnership with Lucent, " says NTT president Jun-ichiro Miyazu. Beginning in the fourth quarter of this year, Lucent will deliver NTT its 80-channel WaveStar OLS400G DWDM system and integrate it with its WaveStar ADM 16/1 line of 2.5 Gb/s synchronous optical hierarchy equipment.
In addition to using Lucent's current DWDM system, NTT expects to be the first service provider to deploy Lucent's new WaveStar 400GL system, which uses an L-band optical amplifier. Running the two DWDM systems in parallel, carriers can transmit up to 160 wavelengths on a single dispersion-shifted fiber, according to Lucent. The company plans to deliver the WaveStar OLS 400GL system in early 2000.
At the bequest of NTT, Lucent designed an L-band amplifier specifically for the dispersion-shifted fiber in many of NTT's routes. Dispersion-shifted fiber was developed to accommodate high bit rate signals, but not high channel counts in the conventional erbium-doped fiber amplifier band. The L-band opens another wavelength window for DWDM channels on the dispersion-shifted fiber.
The NTT project is a departure from L-band applications built to suit new large effective area fibers, notes Kathy Szelag, marketing VP for Lucent's optical networking group. "I wouldn't build an L-band amplifier for every fiber type," she says. Because L-band amplifier applications vary with different fiber types, developing a portfolio full of unique amplifiers to accommodate each fiber need would not be profitable, she explains.
C-band amplification, on the other hand, lends itself to a common platform with evenly-spaced channels because it works well with standard singlemode fiber. "As you move out of the C band and into the L band, you'll see more differentiation between amplifiers," Szelag concludes.