Cost-Effective Transition to 40 Gb/s Line Rate Using the Existing 10 Gb/s-Based DWDM Infrastructure

In this paper, the authors propose and demonstrate a cost-effective technique to upgrade the capacity of Dense Wavelength Division Multiplexing (DWDM) networks to a 40 Gb/s line rate using the existing 10 Gb/s-based infrastructure. To accommodate 40 Gb/s over the link optimized for 10 Gb/s, they propose applying a combination of super-FEC, carrier-suppressed return-to-zero, and pre-emphasis to the 40 Gb/s transponder. The transmission of 40 Gb/s DWDM channels over existing 10 Gb/s line-rate long-haul DWDM links, including 40×40 Gb/s transmission over KT's standard single-mode fiber optimized for 10 Gb/s achieves successful results.