An optical signal processing apparatus includes a removal unit and a superimposition unit. The removal unit receives, from a first optical transmission path, an optical signal converted from an electrical signal, in which a first signal and a second signal having different frequencies from each other have been superimposed, and removes the second signal from the optical signal which has been input. The superimposition unit superimposes a third signal having a frequency different from a frequency of the first signal on the optical signal in which the second signal has been removed by the removal unit, and outputs the optical signal in which the third signal has been superimposed to a second optical transmission path.

An optical signal processing apparatus includes a removal unit and a superimposition unit. The removal unit receives, from a first optical transmission path, an optical signal converted from an electrical signal, in which a first signal and a second signal having different frequencies from each other have been superimposed, and removes the second signal from the optical signal which has been input. The superimposition unit superimposes a third signal having a frequency different from a frequency of the first signal on the optical signal in which the second signal has been removed by the removal unit, and outputs the optical signal in which the third signal has been superimposed to a second optical transmission path.

The concepts and technologies disclosed herein are directed to quantum tampering threat management. According to one aspect of the concepts and technologies disclosed herein, a quantum security manager (“Q-SM”) can monitor a plurality of quantum channels for tampering. The Q-SM can detect tampering on a quantum channel of the plurality of quantum channels. The Q-SM can provide tampering monitoring statistics to a software-defined network (“SDN”) that, in turn, notifies a quantum security operations center (“Q-SOC”) about the tampering on the quantum channel. The Q-SM can receive threat mitigation instructions from the Q-SOC. The threat mitigation instructions can instruct the Q-SM how to counter the tampering on the quantum channel. The Q-SM can perform one or more actions in accordance with the threat mitigation instructions to counter the tampering on the quantum channel.

A communication apparatus includes a plurality of devices, each of the devices includes a monitoring unit that monitors at least one other device and detects an error that has occurred in the other device, and if an error is detected by the monitoring unit, the device performs a device reset indicating a reset of the operating state of the other device by the monitoring unit or a power source reset indicating a reset of the supply of electric power to the communication apparatus by a chain-of-command unit included in the device.

Embodiments relate to a bidirectional free space optical (FSO) communications system. Specifically, data-encoded FSO beams are transmitted and received between two terminals. A transmit (Tx) direction of a beam transmitted from the first terminal is dithered by a beam steering unit (BSU). As the dithered beam is received by the second terminal, the power levels of the beam are measured. The power levels are then encoded in a data-encoded FSO beam transmitted to the first terminal. This allows the first terminal to decode the received FSO beam and determine the power levels. The power levels allow the first terminal to determine Tx direction misalignments and adjust the Tx direction for the Tx beam sent to the second terminal. This process may be repeated to reduce Tx misalignments and may be performed by both terminals such that each terminal sends power level information to the opposite terminal.

Embodiments relate to a bidirectional free space optical (FSO) communications system. Specifically, data-encoded FSO beams are transmitted and received between two terminals. A transmit (Tx) direction of a beam transmitted from the first terminal is dithered by a beam steering unit (BSU). As the dithered beam is received by the second terminal, the power levels of the beam are measured. The power levels are then encoded in a data-encoded FSO beam transmitted to the first terminal. This allows the first terminal to decode the received FSO beam and determine the power levels. The power levels allow the first terminal to determine Tx direction misalignments and adjust the Tx direction for the Tx beam sent to the second terminal. This process may be repeated to reduce Tx misalignments and may be performed by both terminals such that each terminal sends power level information to the opposite terminal.

Aspects of the present disclosure describe physical layer security in optical telecommunications networks wherein a filtering-based physical security is provided by a wavelength tunable distributed fiber optical sensing (DFOS) system operating simultaneously on the telecommunications network.

In an optical network having a terrestrial terminal and an open cable interface (OCI) connecting a submarine cable to a terrestrial cable, the OCI may include a filter positioned on an optical path between the terrestrial cable and the submarine cable and configured to pass first communication signals of a first frequency band, and filter out secondary signals of a second frequency band that does not overlap with the first frequency band. The secondary signals may be looped back to the terrestrial terminal. The terrestrial terminal may detect the looped back secondary signals, and in response, determine the presence of the OCI and that the supervisory signals were rerouted by the OCI.

The present application provides a method for transmitting performance parameters of a far-end optical module of a far-end node, a detection method for detecting performance of a far-end optical module, a method for transmitting control parameters for controlling a far-end optical module of a far-end node, a method for controlling a far-end optical module of a far-end node, a far-end optical module, a near-end optical module, and a fronthaul system. The method for transmitting performance parameters includes: generating, in response to at least one of a plurality of registers of the far-end optical module becoming a first source register, an uplink optical signal according to ID information and a register value of the first source register, where the first source register is a register having a changed register value of the plurality of registers, and register values of the registers have a mapping relationship with performance parameters of the far-end optical module; and transmitting the uplink optical signal to a near-end optical module of a near-end node.

The present invention enables an apparatus or the like, which does not respond to a communication using a superposed signal, to be used in a system using the superposed signal. This control program, which is for a terminal device connectable to a signal processing device through a communication cable, includes: first identification information acquisition steps for acquiring, from the signal processing device, first identification information for identifying the signal processing device in the terminal device; second identification information acquisition steps for acquiring, through an input part of the terminal device, second identification information for identifying an electric apparatus that is electrically connected to the signal processing device and operates an operation element; generation steps for generating association information for associating the first identification information with the second identification information; and output steps for outputting the association information so that the association information is received by the information processing device.