The WDM modules are passive optical devices. They multiplex and de-multiplex the optical signals (wavelengths acc. to ITU-T G.694) of the line interfaces in full duplex. The multiplexing component of these modules merges the channels onto a single fiber. The de-multiplexing
component receives this signal on the other end of the line and separates the signals back into single ITU-T channels. Different types of filter modules are available. Additional optical supervisory channel.
CWDM:
| Granularity down to 4 channels
| Up to 16 channels
| In-service upgrade from 8 to channels
DWDM:
| Granularity down to 8 channels
| Up to 64 channels, < 2.7 Gbps
| Up to 32 channels, @ 10 Gbps