OI2D STM1 Service card

Description

OI2D is a 2xSTM-1 optical interface board. OI2D can be installed in a slot or integrated with SCB

Working principle and signal flow

Receive Direction

The O/E converting module converts a received STM-1 optical signal into an STM-1 electrical signal and sends the STM-1 electrical signal to the data and clock restoration module. The R_LOS alarm signal can be detected in the O/E converting module. The data and clock restoration module restores the clock signal and sends the clock signal and the STM-1 electrical signal to the SDH overhead processing module. Then, the SDH overhead processing module extracts the overhead bytes from the received STM-1 signal and sends the payload signal to the cross-connect unit through the backplane. The R_LOF alarm signal, R_OOF alarm signal, and other alarm signals are detected in the SDH overhead processing module

Transmit Direction

The SDH overhead processing module inserts the overhead bytes into the electrical signal sent from the cross-connect unit and sends the electrical signal to the E/O converting module. Then, the E/O converting module converts the STM-1 electrical signal into an STM-1 optical signal and sends the STM-1 optical signal to fibers for transmission

Logic Control Module

This module generates the timing clock signal and frame header for the board, and controls the ALS function

Power Unit

This unit provides DC power for all the modules of the board