The OTM16 is a bi-directional transponder and optical signal-conditioning module for WDM applications in long-haul repeaterless optical links.

It combines in one unit the transmitter and the receiver functions for one tributary optical interface as well as the line optical interface.

OTM-16
The OTM16 transponder is a clear-channel optical module used to extend the link transmission distance and/or increase WDM capacity. Each pair of transponders accommodates one OC-48 / STM-16 channel.

In the line transmit direction, the transponder accepts either a 1310 nm or 1550 nm NRZ optical signal and grooms it for transmission in the 1550 nm band. Grooming includes Stimulated Brillouin Scattering suppression and an optical/electrical/optical regeneration process whereby the transponder encodes and overlays forward error correction (FEC) code.

- User-replaceable ITU grid laser source for line transmission
　(minimizes spares inventory for DWDM networks)
- Optical line output with high extinction ratio
- Stimulated Brillouin Scattering (SBS) suppression to allow increased booster launched powers
- Out-of-Band Forward Error Correction (FEC): Typical channel gain improvement of 5.5 dB
- SDH Overhead monitoring on the line and tributary inputs
- 10 Mb/s user data channel between pairs of OTM16s

Transponder Subrack
Up to eight OTM16 transponders can be housed in the MPB subrack. The subrack comes fully equipped with an alarm and supervision unit and a network element controller, to ensure constant control and monitoring of all of the elements housed in the subrack either locally or remotely.

- Houses eight OTM16 bi-directional transponder modules
- Hot swappable ? modules can be replaced without powering down the subrack unit
- Expandable design accommodates multiple subrack arrangements
- Intra-subrack communications prevents wavelength duplication
- Coloured DWDM line interfaces

Performance Monitoring
- For Sonet/SDH, based on the B1 byte, as per ITU-T G.826:
　- BBE Background Block Errors
　- ES Errored Seconds
　- UT Unavailable Time
　- SES Severely Errored Seconds
- FEC line-corrected errors.

Optical Specifications