scope:

The purpose of this Recommendation is to provide optical interface specifications for the realization of transversely compatible bidirectional dense wavelength division multiplexing (DWDM) systems, primarily intended for metro applications. The tail-end equipment (TEE) transmitters have the capability to automatically adapt their DWDM channel frequency to the optical demultiplexer/optical multiplexer (OD/OM) or optical add/drop multiplexer (OADM) port. They are connected to using feedback from the head-end equipment (HEE) via the head-to-tail message channel (HTMC).

This Recommendation defines and provides values for optical interface parameters of point-to-point DWDM applications on single-mode optical fibres through the use of the "black link" approach with both of the propagation directions sharing the same optical fibre end-to-end.

For the applications in this version of the Recommendation, the black link does not contain optical amplifiers.

This Recommendation describes bidirectional DWDM systems that include the following features:

- minimum channel frequency spacing: 50 GHz for 10 Gbit/s and 100 GHz for 25 Gbit/s;

- bit rate of signal channel: 10 Gbit/s and 25 Gbit/s;

- maximum transmission distance: 20 km for 10 Gbit/s and 10 km for 25 Gbit/s;

- maximum capacity: 40 bidirectional channels at 10 Gbit/s and 20 bidirectional channels at 25 Gbit/s.

Specifications are organized according to the application codes.