OPTICAL NETWORK UNIT AND ABNORMAL DETECTING & POWER MONITORING METHOD THEREOF

An optical network unit includes an optical transmitter, an optical detector and a signal measurement module. The optical transmitter transmits an optical signal to an optical line terminal of a passive optical network system. The optical detector is utilized for monitoring the emission of the optical signal and transforming the received optical signal into a current signal. Then, the current signal is transformed into a voltage signal. The signal measurement module is connected to the optical detector for filtering and sampling the voltage signal and generating a sampling signal. The average output power of the optical transmitter can be obtained by averaging the voltage values of the sampling signal. Once the up-transmission data packet of the optical network unit exceeds the time interval of the allocated time slot, and the voltage values of the sampling signal have several points over a threshold, the optical transmitter is turned off. Furthermore, an abnormal detecting & power monitoring method of the optical network unit is also disclosed herein.