Summary

This Recommendation defines the requirements for the optical transport module of order n (OTM‑n) signals of the optical transport network, in terms of:

����������� optical transport hierarchy (OTH);

����������� functionality of the overhead in support of multi-wavelength optical networks;

����������� frame structures;

����������� bit rates;

����������� formats for mapping client signals.

The first revision of this Recommendation includes the text of Amendment 1 (ODUk virtual concatenation, ODUk multiplexing, backward IAE), extension of physical interface specification, ODUk APS/PCC signal definition and several editorial enhancements.