Methods and systems for reducing power consumption in a multi-channel passive optical network (PON). A processor in the PON may monitor the channels in the multi-channel PON to detect a currently inactive channel, determine whether the detected channel has been inactive for an extended period of time, and deactivate the detected channel (by deenergizing transmitter(s) and/or receiver(s) associated with the detected channel) in response to determining that the channel has remained inactive for an extended period of time. The processor may re-activate the channel in response to determining that an optical signal has been reliably present on the channel for a sufficient period of time.

An object is to provide an optical transmission apparatus in which dummy lights can be arranged according to an arrangement of optical signals. A plurality of optical signals of different frequencies arranged in a frequency grid are input to a multiplexing unit and the multiplexing unit multiplexes the input optical signals. A dummy light output unit identifies a dummy light to be arranged in the frequency grid based on the plurality of optical signals and outputs the dummy light. A multiplexing unit multiplexes an optical signal multiplexed by the multiplexing unit and the dummy light output from the dummy light output unit to output a wavelength-multiplexed optical signal L.

Systems and methods for resolving control conflicts in trunk protection links are provided. A method, in one implementation, includes identifying control conflicts among Network Elements (NEs) in an Optical Multiplex Section (OMS). The OMS may have a plurality of trunk protection links arranged in parallel and a plurality of Trunk Protection Switches (TPSs). Also, the trunk protection links and TPSs are configured to create a distributed 1:N trunk protection arrangement. The method also includes resolving the control conflicts by auto-negotiating a primary instance associated with enabling a first set of control actions to be conducted along a primary path in the OMS and auto-negotiating one or more follower instances associated with enabling a second set of control actions to be conducted along one or more secondary paths in the OMS subsequent to the first set of control actions.

An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Provided is a wavelength path communication node device with no collision of wave lengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

A transmission device including: a signal power detection circuit that detects signal power of a wavelength-division-multiplexed optical signal to be transmitted to a transmission line into which pumping light is inputted from a Raman amplifier; a variable optical attenuator that attenuates the wavelength-division-multiplexed optical signal; and a control circuit that reduces an attenuation amount of the variable optical attenuator depending on an increase in the signal power.

Processing a received optical signal in an optical communication network includes equalizing a received optical signal to provide an equalized signal, demodulating the equalized signal according to an m-ary modulation format to provide a demodulated signal, decoding the demodulated signal according to an inner code to provide an inner-decoded signal, and decoding the inner-decoded signal according to an outer code. Other aspects include other features such as equalizing an optical channel including storing channel characteristics for the optical channel associated with a client, loading the stored channel characteristics during a waiting period between bursts on the channel, and equalizing a received burst from the client using the loaded channel characteristics.

Example optical signal processing apparatuses and methods are provided. One example apparatus includes: N light sources, a wavelength multiplexer, an optical processor, a dither application circuit, a first detection circuit, a second detection circuit, and a feedback control circuit. The light source generates a single-wavelength signal. The dither application circuit applies a dither signal to the light source. The wavelength multiplexer generates a multi-wavelength signal based on the single-wavelength signal. The first detection circuit is configured to obtain a first power signal of a signal input to the optical processor. The second detection circuit is configured to obtain a second power signal of a signal output from the optical processor. The feedback control circuit adjusts a working parameter of the optical processor based on the dither signal corresponding to the single-wavelength signal, the first power signal, and the second power signal.

A dummy optical signal generation apparatus includes a multi-longitudinal mode laser configured to provide a light source signal. The dummy optical signal generation also includes a comb optical bandpass filter. The light source signal provided by the multi-longitudinal mode laser outputs a dummy optical signal through the comb optical bandpass filter. The dummy optical signal is an optical signal that does not comprise service information.

A wavelength conversion device includes: a memory; and a processor configured to: receive transmission signal light in which first wavelength division multiplexing signal light and second wavelength division multiplexing signal light that have different wavelength bands in which a plurality of rays of main signal light is wavelength-multiplexed are combined with supervisory control signal light that relates to supervisory control of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light from a transmission line and that demultiplexes the supervisory control signal light from the transmission signal light; detect input power of the supervisory control signal light; demultiplexer each of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light from the transmission signal light; convert at least one of the wavelength bands of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light.