Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously overcome problems encountered when operating DFOS systems over operational telecommunications facilities namely, cross-phase modulation, and uneven amplitude profiles through the use of a novel constant amplitude coded DFOS employing suppressed out-of-band signaling.

An optical communication fiber link including a monitoring system connected to an optical fiber transmitting electromagnetic radiation including a communication. The monitoring system includes a detection system detecting a scattering of the electromagnetic radiation from the optical fiber. The monitoring system monitors the scattering for an abnormal change and determines, from the abnormal change, an absence or a presence of a fault in the optical fiber.

An optical communication fiber link including a monitoring system connected to an optical fiber transmitting electromagnetic radiation including a communication. The monitoring system includes a detection system detecting a scattering of the electromagnetic radiation from the optical fiber. The monitoring system monitors the scattering for an abnormal change and determines, from the abnormal change, an absence or a presence of a fault in the optical fiber.

Disclosed are apparatuses and testing methods for emulating an Optical Network Terminal (ONT) device for communicating or otherwise working with an Optical Line Terminal (OLT) device that was configured to operate with the ONT device. Such emulation may include configuring various settings of the apparatus so that the apparatus may appear to the OLT to be the ONT device. For example, the emulation may include accessing and using authentication/authorization related settings and network configuration settings of the ONT, thus permitting the apparatus to connect to a Passive Optical Network and test services and the quality of service experience without having to reconfigure the OLT.

Disclosed are apparatuses and testing methods for emulating an Optical Network Terminal (ONT) device for communicating or otherwise working with an Optical Line Terminal (OLT) device that was configured to operate with the ONT device. Such emulation may include configuring various settings of the apparatus so that the apparatus may appear to the OLT to be the ONT device. For example, the emulation may include accessing and using authentication/authorization related settings and network configuration settings of the ONT, thus permitting the apparatus to connect to a Passive Optical Network and test services and the quality of service experience without having to reconfigure the OLT.

Disclosed are apparatuses and testing methods for emulating an Optical Network Terminal (ONT) device for communicating or otherwise working with an Optical Line Terminal (OLT) device that was configured to operate with the ONT device. Such emulation may include configuring various settings of the apparatus so that the apparatus may appear to the OLT to be the ONT device. For example, the emulation may include accessing and using authentication/authorization related settings and network configuration settings of the ONT, thus permitting the apparatus to connect to a Passive Optical Network and test services and the quality of service experience without having to reconfigure the OLT.

Disclosed are apparatuses and testing methods for emulating an Optical Network Terminal (ONT) device for communicating or otherwise working with an Optical Line Terminal (OLT) device that was configured to operate with the ONT device. Such emulation may include configuring various settings of the apparatus so that the apparatus may appear to the OLT to be the ONT device. For example, the emulation may include accessing and using authentication/authorization related settings and network configuration settings of the ONT, thus permitting the apparatus to connect to a Passive Optical Network and test services and the quality of service experience without having to reconfigure the OLT.

In order to readily carry out communication between terminal stations, a submarine optical communication system includes a first terminal station including a first monitoring means for monitoring the signal quality of dummy light a first dummy light source that outputs dummy light to the second terminal station, and a first light transmitting means for transmitting an optical signal to the second terminal station, the optical signal including a first signal quality of the dummy light; and the second terminal station including a second dummy light source that outputs dummy light to the first monitoring means, a second monitoring means for monitoring the signal quality of the dummy light, and a light receiving means for receiving the optical signal.

In order to readily carry out communication between terminal stations, a submarine optical communication system includes a first terminal station including a first monitoring means for monitoring the signal quality of dummy light a first dummy light source that outputs dummy light to the second terminal station, and a first light transmitting means for transmitting an optical signal to the second terminal station, the optical signal including a first signal quality of the dummy light; and the second terminal station including a second dummy light source that outputs dummy light to the first monitoring means, a second monitoring means for monitoring the signal quality of the dummy light, and a light receiving means for receiving the optical signal.

In order to detect a terminal station in which a failure has occurred in a WDM optical transmission system that transmits optical signals transmitted thereto from a plurality of terminal stations after performing wavelength multiplexing of said optical signals, this failure detection device includes: an input unit that receives first optical signals from the plurality of terminal stations, the first optical signals having wavelengths respectively allocated to the plurality of terminal stations on the basis of allocation information, and that joins the received first optical signals; a monitoring unit that outputs monitoring signals, which are signals that are in accordance with the intensities corresponding to the respective wavelengths of the joined first optical signals; and an identifying unit that identifies a first terminal station from the plurality of terminal stations on the basis of the allocation information and the monitoring signals.