提出了一种带有光监控通道（OSC）子系统的光传送网（OTN）分层结构模型，分析了OSC中的信号特点，指出OSC信号质量决定了运行、管理和维护（OAM）信号的可靠性。依据Q值与误码率（BER）的一一对应关系，提出了一种可在线监测OSC信号Q值的方案，并基于数字信号处理芯片（DSP）技术设计了监测模块，实现了OSC信号在线Q值监测。

In this paper, a hierarchical model of the optical transport network (OTN) with an optical supervisory channel (OSC) subsystem is discussed, and that the reliability of operation, administration and management (OAM) signals is rested with the quality of signals transported in OSC is indicated by analyzing the charac-teristics of signals in OSC. Basing on the one-to-one correspondence of Q-factor with bit-error-ratio (BER) in data communication systems, an on-line supervisory scheme for Q-factor of signals in OSC is presented, and the supervisory module by a digital signal processor (DSP) approach is designed to implement on-line supervision for Q-factor.