Patent ID: 8682163

Claim:
A central office subsystem, comprising: an Optical Distribution Network (ODN) interface, an optical receiver, a first optical emitter, a second optical emitter, a test processing unit, and a control unit, wherein the ODN interface is configured to be connected to an ODN; wherein the optical receiver is coupled with the ODN interface, and is configured to receive an optical signal used for uplink data transmission, wherein a wavelength of the optical signal used for the uplink data transmission is a second wavelength; wherein the first optical emitter is coupled with the ODN interface, and is configured to send an optical signal used for downlink data transmission, wherein a wavelength of the optical signal used for the downlink data transmission is a first wavelength; wherein the test processing unit is configured to generate a test excitation signal, send the generated test excitation signal to the second optical emitter, perform time-domain or frequency-domain analysis on an optical signal reflected and/or scattered by the ODN, and obtain line evaluation information of the ODN; wherein the second optical emitter is configured to emit an optical signal bearing the test excitation signal with the second wavelength; and wherein the control unit is configured to specify a test window, and control the test processing unit to send and receive a signal in the specified test window.