An eight-wavelength WDM ring network survivability experiment on NTT´s regional fiber network

Wavelength-division multiplexing (WDM) networks are very attractive because of their high flexibility and throughput. WDM ring networks employing optical add/drop multiplexers (OADMs) are especially promising because they enable the node configuration to be simplified by utilizing passive optical components and increase the survivability against fiber cuts. Previously we have demonstrated the robustness of a pre-prototype of a WDM ring network under stable laboratory conditions. However, field experiments are necessary because the stability of each network element and component must be confirmed under the adverse conditions of a real environment. In addition, the validity of the restoration function including control scheme of optical amplifiers and the transportation of supervisory information must be also confirmed. In this paper, we report on the survivability of a WDM ring network with experimental restoration functions, as obtained in experiments conducted on one of NTT´s regional fiber networks