Abstract: Provided are a ranging method and a communication method for an optical network, an Optical Line Terminal (OLT), an Optical Network Unit (ONU), and an optical network system. The OLT sends a broadcast message to the ONU, the broadcast message being used to indicate an uplink bandwidth allocated to the ONU. The OLT opens a quiet window for the ONU in a predetermined region. The OLT receives an uplink signal sent by the ONU at the quiet window.

Abstract: Provided are a ranging method and a communication method for an optical network, an Optical Line Terminal (OLT), an Optical Network Unit (ONU), and an optical network system. The OLT sends a broadcast message to the ONU, the broadcast message being used to indicate an uplink bandwidth allocated to the ONU. The OLT opens a quiet window for the ONU in a predetermined region. The OLT receives an uplink signal sent by the ONU at the quiet window.

Abstract: At least some embodiments of disclosure provide a method and device for optical fiber monitoring and an optical fiber adapter. The method includes: a device for monitoring the optical fiber for performing optical fiber monitoring is installed in an optical fiber adapter and the optical fiber monitoring is performed by using the optical fiber adapter with the device for monitoring the optical fiber. The problem that the device for monitoring the optical fiber has complex wiring and a deployment position is limited is solved. And effects that the wiring complexity of the device for monitoring the optical fiber is reduced, and the deployment position is flexible and convenient are achieved.

Abstract: The disclosure relates to an OTDR path detection device and method, and the device includes an optical input interface, an optical output interface, a test light transmission unit, an optical assembly, a test light reception unit, a data processing unit, a micro control unit, a power supply unit and a communication interface unit. In the disclosure, a detection light transmission function, a scattered light and reflected light reception function, a detected data processing function and a unit control function are integrated. A fiber optic network to be detected can be detected in real time through fixing the integral optical transmission/reception device in a fiber optic network to be detected, and the normal transmission of serving light is not affected, thus a specialized OTDR meter for fiber optic detection and related testing devices are no longer needed, thereby simplifying steps for optical fiber failure detection and lowering complexity of optical network maintenance and corresponding cost.

Abstract: Provided are an optical transceiving device and method. This device includes: an OTDR transmitter, an OTDR receiver, an input optical interface, an output optical interface, a housing, a splitter, and a sideband filter, and by means of a technical scheme of the present disclosure, this device has a function of sending and receiving OTDR detection optical signals, supports a function of wave multiplexing/de-multiplexing of detection optical signals and service optical signals, guarantees that transmission of the service optical signals and the detection optical signals on a main optical path do not influence each other, and may be taken as an important part of an optical module and be integrated into an optical transmission system device, enables an OTDR detection function to be set inside a system, and reduces an operation and maintenance cost of optical fibre failure detection.

Abstract: The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

Abstract: The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

Abstract: The present invention discloses a passive optical network system based on wavelength protection and the protection backup method thereof. It comprises an optical line terminal (OLT) with two interface circuits, two trunk lines, an optical splitter network, multiple branch lines and optical network units (ONU), each of which is with two interface circuits. The two interface circuits of the OLT transmit downlink optical signals with different wavelengths, while the two interface circuits of the ONU transmit uplink optical signals with different wavelengths. Each trunk line is set with a wavelength division multiplexing (WDM) device and it can only pass the uplink and downlink signals of the connected interface circuits.

Abstract: The present invention discloses a passive optical network system based on wavelength protection and the protection backup method thereof. It comprises an optical line terminal (OLT) with two interface circuits, two trunk lines, an optical splitter network, multiple branch lines and optical network units (ONU), each of which is with two interface circuits. The two interface circuits of the OLT transmit downlink optical signals with different wavelengths, while the two interface circuits of the ONU transmit uplink optical signals with different wavelengths. Each trunk line is set with a wavelength division multiplexing (WDM) device and it can only pass the uplink and downlink signals of the connected interface circuits.