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 optical communication system includes a primary transceiver, a component, and secondary transceivers. The primary transceiver is operable to supply first optical subcarriers to an optical communication path, the first optical subcarriers being amplitude modulated at a first frequency to carry first control information and amplitude modulated at a second frequency to carry second control information. The component is operable to be coupled to the optical communication path and includes circuitry operable to detect the first control information. The secondary transceivers are coupled to a terminal end of the optical communication path. At least one of the secondary transceivers is operable to detect the second control information and block the first control information.

An example system includes a plurality of hub transceivers and a plurality of edge transceivers. A first hub transceiver is operable to determine that the first hub transceiver is configured to assign a first subset of network resources to a first subset of the edge transceivers for communication over an optical communications network, and determine that a second hub transceiver is configured to assign a second subset of network resources to a second subset of the edge transceivers for communication over the optical communications network. The first hub transceiver is also operable to determine that the first subset of network resources overlaps the second subset of network resources, and in response, transmit a notification of the overlap to a control module of the optical communications network.

A multiplexer inserts a dummy signal light into a main signal. A light intensity monitor acquires the intensity of the light of each wavelength of a light output from a wavelength selective switch. A light source controller controls the insertion of the dummy signal light into the main signal, and release of the insertion. A difference calculator calculates the difference between a first light intensity that has been acquired in a state in which the dummy signal light is inserted into the main signal and a second light intensity that has been acquired in a state in which the dummy signal light is not inserted into the main signal. An insertion loss calculator calculates an insertion loss in the wavelength selective switch based on the calculated difference. An insertion loss controller controls the insertion loss in the wavelength selective switch based on the calculated insertion loss.

An optical communication system that comprises a transmitter adapted to generate a signal by modulating a transmission data as low power consumption symbols of an amplitude modulation format and a monitoring data (MD) as high power consumption symbols of the amplitude modulation format, the MD comprising at least one transmitter parameter and/or at least one receiver parameter of communicating the transmission data. A binary logarithm of a total number of the low power consumption symbols and the high power consumption symbols is a non-integer.

Systems and methods for transmission filtering are provided. A receiver includes an input coupled to a transmission line to receive distorted optical symbols. A distortion filter is coupled to the input to replace the distorted optical symbols with predicted symbols using a trained neural network. A decoder is coupled to the distortion filter to decode the predicted symbols.

Communication devices, communication systems and communication methods that implement transmission lane information are disclosed. In one example, circuitry is configured to receive transmission lane information from each of a plurality of reception lanes and to generate physical lane correspondence information based on the received transmission lane information, wherein the transmission lane information identifies a plurality of transmission lanes of a device that transmitted the transmission lane information. The physical lane correspondence information indicates a correspondence relationship between the plurality of transmission lanes and the plurality of reception lanes.

A transmission device configured to transmit main signal light to another transmission device through a transmission line, the transmission device includes a transceiver configured to output supervisory signal light including information on supervisory control on the transmission device and the other transmission device, an attenuator configured to attenuate the supervisory signal light, a combiner configured to combine the supervisory signal light to the main signal light, and a control circuit configured to control an attenuation amount of the attenuator so that power of the supervisory signal light received by the other transmission device approaches a given target value.

A method for calibrating an OLTS includes calibrating a first optical power meter of the OLTS using a stabilized light source. The method further includes calibrating a second optical power meter of the OLTS using the stabilized light source. The method further includes setting a power of an internal light source using the calibrated first optical power meter. A calibration cable is connected to a first test port and a second test port during setting of the power level, and a connection of the calibration cord to the second test port is maintained between calibrating of the second optical power meter and setting of the power level.

An optical signal transmission apparatus generates a multi-level optical signal from a multi-level electric signal. The optical signal transmission apparatus detects, based on a supervisory signal generated from an optical signal, an electric-to-optical (E/O) conversion characteristic of an E/O converter configured to convert an electric signal into an optical signal. For example, when the E/O converter generates a multi-level optical signal from a multi-level electric signal based on a bias signal, the optical signal transmission apparatus determines a correspondence relationship between the bias signal and the optical signal. The optical signal transmission apparatus adjusts a use range of intensities of the bias signal based on the determined correspondence relationship so that the E/O converter may linearly operate.

A system and method for automatically calibrating loopback data in a line monitoring system of an optical communication system. Extra peaks in loopback data are calibrated out of the loopback data used by the system by identifying pairs of peaks in the loopback data associated with test signal transmissions through the same high loss loopback path from opposite ends of the optical transmission path.