scope:

This Recommendation applies to optical interfaces for coarse wavelength division multiplexing (CWDM) optical line systems for network applications using single-mode optical fibres. This Recommendation defines and provides values for optical interface parameters of physical point-to-point and ring CWDM system applications. Their principal purpose is to enable transversely (multi-vendor) compatible interfaces.

Applications are defined using two different methods, one using multichannel interface parameters and the other using single-channel interface parameters. Both unidirectional and bidirectional applications are specified.

This Recommendation describes optical line systems that include the following features:

- Maximum number of channels: Up to 16;

- Bit rate of signal channel: Up to PAM4 50G.

The CWDM wavelength grid is provided in [ITU-T G.694.2].

Specifications are organized according to application codes.

In the future, applications enabling full transverse compatibility at both the multichannel and single-channel interface points may be included.