The modules are used in the CN 4200 in both standard add/drop and ROADM configurations and provide the following functionality:

• Selective add/drop of four or eight adjacent channels (depending on VMUX type)
• Blocking of four or eight add/drop channels in express path
• Express of all non-add/drop channels
• Automatic power management on each add channel
• Provisioning (module level)
• Alarm and fault reporting
• Maintenance and diagnostics

Unlike passive filters that rely on the installation of external attenuators to accomplish wavelength power balancing, the VMUX-4 and VMUX-8 modules provide the CN 4200 with the ability to automatically control the optical power of the fixed wavelengths being added and terminated. Automatic power control is based on embedded software that adjusts the power levels for added, dropped and express traffic traversing the node with no user intervention to provide optimal transmission performance.

The two types of VMUX modules support either four or eight channels respectively; both types support the full 40-channel plan. The VMUX modules drop and add adjacent channel wavelengths from/to the aggregated optical signal on the network express paths. The channel wavelengths dropped/added are determined by the type of VMUX. Dropped channels are blocked from the express path through the module. The VMUX modules use Variable Optical Attenuators (VOAs) in both directions to provide automatic power balancing on the dropped/added channels.

The VMUX modules can be deployed in either terminal or OADM configurations and are fully interoperable with the Wavelength Selective Switch (WSS)-based DWR module, facilitating participation in ROADM networks and allowing operators to create more cost-efficient hybrid ROADM/VMUX networks. An operator can deploy DWR in a hybrid network to meet growth needs where flexibility is required—for dynamic services or when capacity projection is uncertain—and use VMUX with smaller nodes or static services with more certain projections. Both VMUX and DWR can be deployed within the same node and support automatic channel power management.

Ciena may make changes from time to time to the products or specifications contained herein without notice.