optical transport module (OTM)

Optical Transport Module (OTM) is a frame structure specified in ITU-T recommendationG.709 for an asynchronous transport medium.

The frame structure, which is similar to the SDH frame structure, is designed for optical transmission channels. In the OTM frame structure is a forward error correction( FEC), which is used to correct transmission errors.

When aligned with the optical transport network, data rates are 2.7 Gbit/s forOTU1, 10.7 Gbit/s for OTU2, and 43 Gbit/s for OTU3, depending on the optical transport unit ( OTU). The user data consists of the Synchronous Transport Modules( STM) STM-16, STM-64 and STM-256.