Systems and methods for a scalable Open Shortest Path First (OSPF) deployment for optical networks include steps of causing communication to a router connected to a data communication network, for North-South communication; causing communication to a management plane associated with the optical network via one or more interfaces that are each connected to one or more Open Shortest Path First (OSPF) domains, for East-West communication; and implementing an OSPF terminator between the one or more OSPF domains that includes receiving OSPF packets, sending self-generated OSPF packets, and preventing flooding of received OSPF packets between the one or more OSPF domains.

This application discloses an optical amplifier apparatus including a first amplifier unit and a hybrid filter unit. The first amplifier unit is configured to receive a first beam including signal light and first monitoring light. The first amplifier unit is further configured to amplify the first beam to obtain a second beam. The hybrid filter unit is configured to: receive the second beam output by the first amplifier unit, and separate the first monitoring light and the signal light from the second beam. The hybrid filter unit is further configured to: transmit the first monitoring light in the second beam to a monitoring light detection apparatus of a first station through a first output port. The hybrid filter unit is further configured to: perform gain flattening filtering processing on the signal light in the second beam to obtain filtered signal light, and output the filtered signal light.

System and method for fiber-optic time frequency and data joint transmission, comprising local end, relay nodes, and remote end. In each local end, relay node, and remote end, multiplexing and demultiplexing of time frequency signals, optical supervisory signals, and optical communication data services are performed by CWDM modules and OSC-band wavelength multiplexer/demultiplexers, and processing (transmitting, relaying, receiving) is performed by corresponding processing modules for joint transmission. A sub-band of standard OSC band is used for transmitting time frequency signal so that transmission of optical supervisory signal is not influenced while no extra band resource is occupied with improved utilization of wavelength resources and reduced costs. Wavelengths of time and frequency transfer in both directions in sub-band of OSC band are flexibly selected and combined to meet different requirements; wavelengths are close or same so that bidirectional symmetry of the link is guaranteed to the maximum with improved precision.

There is provided apparatuses to detect occurrence and location of damages on optical fiber links in advance by converting an optical span in optical network to an interferometry based sensing media. The interferometry based sensing media may enable detection of mechanical perturbation or mechanical vibration occurred on optical fiber links across optical network. The system employed with the interferometry based sensing media can detect occurrence of mechanical perturbation or mechanical vibration as well as discover the location of such event occurred using standard interferometry based sensing techniques.

In order to enable more stable monitoring of communication status, a communication device is provided with: a setting unit which sets a first wavelength selected from wavelength selection alternatives included in wavelengths of light included in dummy light, and a first transmission power which is selected in accordance with a first communication status from a plurality of transmission power selection alternatives that are set in advance; a generation unit which generates light of the first wavelength from the dummy light; an adjustment unit which adjusts the light of the first wavelength to first light of the first transmission power; and a multiplexing unit which multiplexes the first light with communication light serving as light for a predetermined communication so as not to overlap each other on the time axis, and which delivers the multiplexed light to another communication device.

There is provided a reception device including a receiver configured to receive a wavelength-multiplexed optical signal so as to generate a wavelength-multiplexed signal, a filter configured to pass through the wavelength-multiplexed signal having a specific wavelength and an adjacent wavelength to the specific wavelength from the wavelength-multiplexed signal, and a processor configured to detect a specific signal having the specific wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter, and detect a first supervisory control signal having the specific wavelength and a second supervisory control signal having the adjacent wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter.

A transmission device that transmits main signal light to another transmission device via a transmission path, the transmission device includes a transmitter that generates monitoring signal light with intensity modulation based on a signal related to monitoring control of the transmission device and the other transmission device, a multiplexer that multiplexes the monitoring signal light into the main signal light, a receiver that acquires light receiving information from the other transmission device, the light receiving information being related to a light receiving state of the monitoring signal light, and a control circuit that controls a modulation degree of the intensity modulation in accordance with the light receiving information.

Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, an apparatus includes an optical tap coupled to an optical communication path carrying a modulated optical signal carrying a plurality of optical subcarriers. The optical tap has a first output configured to supply a first portion of the modulated optical signal and a second output configured to supply a second portion of the modulated optical signal. The plurality of optical subcarriers are amplitude modulated based on control data at a first frequency, and each of the plurality of optical subcarriers is modulated to carry user data at a second frequency greater than the first frequency. The apparatus is configured to supply the control based on the first portion of the modulated optical signal.

Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, an apparatus includes laser operable to supply an optical signal, a digital signal processor operable to supply digital signals, a digital to analog circuitry operable to provide analog signals based on the digital signals, and driver circuitry is coupled to the digital to analog circuitry and operable to supply at least one drive signal. The apparatus also includes a modulator operable to receive said at least one drive signal, modulate the optical signal based on said at least one drive signal to provide a plurality of optical subcarriers, amplitude modulate the plurality of optical subcarriers at a first frequency to carry first control information, and modulate the plurality of subcarriers at a second frequency to carry second control information.

Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, a transmitter includes a laser operable to supply an optical signal, a digital signal processor operable to supply first electrical signals based on first data input to the digital signal processor and second data input to the digital signal processor, digital-to-analog conversion circuitry operable to output second electrical signals based on the first electrical signals, modulator driver circuitry is operable to output third electrical signals based on the second electrical signals, and an optical modulator operable to supply first and second modulated optical signals based on the third electrical signals. The first modulated optical signal includes a plurality of optical subcarriers carrying user data. The second modulated optical signal is polarization modulated based on the second data.