An optical network includes an arrangement of optical nodes. An optical node of the arrangement, and corresponding method, perform optical connectivity discovery and negotiation-less optical fiber continuity verification in the optical network. An overall topology of optical connectivity provisioned for the arrangement is discovered by the optical node based on messages received from a management network communicatively coupling the optical nodes to each other. The optical node synchronizes, temporally and sequentially, with the other optical nodes based on the messages received, assigns fiber of the overall topology, based on a verification sequencing method, to verification slots of a verification sequence, and verifies continuity of fiber according to the verification slots of the verification sequence. The discovery, synchronization, and assignment operations enable the optical node and peer node to perform the optical fiber continuity verification in a symmetric, decentralized, and negotiation-less manner.

An optical network includes an arrangement of optical nodes. An optical node of the arrangement, and corresponding method, perform optical connectivity discovery and negotiation-less optical fiber continuity verification in the optical network. An overall topology of optical connectivity provisioned for the arrangement is discovered by the optical node based on messages received from a management network communicatively coupling the optical nodes to each other. The optical node synchronizes, temporally and sequentially, with the other optical nodes based on the messages received, assigns fiber of the overall topology, based on a verification sequencing method, to verification slots of a verification sequence, and verifies continuity of fiber according to the verification slots of the verification sequence. The discovery, synchronization, and assignment operations enable the optical node and peer node to perform the optical fiber continuity verification in a symmetric, decentralized, and negotiation-less manner.

A method and a device used for remote control by optical fiber signals and power over Ethernet includes a power sourcing equipment (PSE) outputting a direct current (DC) via at least one network cable to at least one powered device (PD). When the PSE receives a second restarting signal from a signal controller, the PSE stops supplying power to the at least one PD. An optoelectric signal converter converts an optical signal from an Ethernet Switch to a digital signal for the signal controller. When the optical signal is determined by the signal controller to be interrupted after a first time duration passes, the signal controller outputs the second restarting signal to the PSE for restarting. After restarting, the PSE re-powers the at least one PD. The at least one PD is restarted remotely without requiring working personnel at the location of the at least one PD, improving restarting efficiency.

A method and a device used for remote control by optical fiber signals and power over Ethernet includes a power sourcing equipment (PSE) outputting a direct current (DC) via at least one network cable to at least one powered device (PD). When the PSE receives a second restarting signal from a signal controller, the PSE stops supplying power to the at least one PD. An optoelectric signal converter converts an optical signal from an Ethernet Switch to a digital signal for the signal controller. When the optical signal is determined by the signal controller to be interrupted after a first time duration passes, the signal controller outputs the second restarting signal to the PSE for restarting. After restarting, the PSE re-powers the at least one PD. The at least one PD is restarted remotely without requiring working personnel at the location of the at least one PD, improving restarting efficiency.

In some examples, a tunable dense wavelength division multiplexing (DWDM) optical time-domain reflectometer (OTDR) may include a fiber optic link analyzer, executed by at least one hardware processor, to determine, based on a user input, for a fiber optic link of a plurality of fiber optic finks of a fiber optic cable, whether the fiber optic fink is active or not active. The DWDM OTDR may specify, based on a determination that the fiber optic fink is active, a test wavelength that is different from a data transmission wavelength of data transmitted by the fiber optic fink. A DWDM multiplexer may be collocated with the DWDM OTDR to selectively connect, based on the specified test wavelength, the DWDM OTDR to the fiber optic fink of the plurality of fiber optic links for testing of the fiber optic link.

Aspects of the present disclosure describe distributed fiber optic sensor systems, methods, and structures that advantageously enable/provide for the proper placement/assignment of sensors in the DFOS network to provide for high reliability, fault tolerant operation that survives fiber failures.

Two photons in an entangled state of polarization is created by parametric down conversion of a pump light. A first photon of the two photons is sent to a sender while a second photon of the two photons is sent to a receiver. The second photon is divided into a first component and a second component. The receiver makes the first component interact with an isotropic nonlinear optical medium. The sender selects the angle of a polarizer according to a signal that he wants to transmit to the receiver and measures the first photon after it passes the polarizer. The receiver mixes the first component and the second component by a half beam splitter. The receiver knows the signal by measuring the probability of photon detection of two output lights from the half beam splitter.

Two photons in an entangled state of polarization is created by parametric down conversion of a pump light. A first photon of the two photons is sent to a sender while a second photon of the two photons is sent to a receiver. The second photon is divided into a first component and a second component. The receiver makes the first component interact with an isotropic nonlinear optical medium. The sender selects the angle of a polarizer according to a signal that he wants to transmit to the receiver and measures the first photon after it passes the polarizer. The receiver mixes the first component and the second component by a half beam splitter. The receiver knows the signal by measuring the probability of photon detection of two output lights from the half beam splitter.

The purpose of the present invention is to provide a device for optical frequency domain reflectometry and a method thereof that can measure a reflectance distribution with less spatial resolution degradation due to a phase noise, without using a wideband receiving system even when a long-distance measurement is performed. The device for optical frequency domain reflectometry according to the present invention is provided with a delay optical fiber for delaying a local light by a prescribed time, and obtains information on a relative delay of a backscattered light from an optical fiber under measurement with respect to the local light and information on the positivity and the negativity of a beat frequency by measuring an in-phase component and a quadrature component of a beat signal obtained by multiplexing the backscattered light from the optical fiber under measurement and the local light delayed by the delay optical fiber, so as to obtain a reflectance distribution in a longitudinal direction of the optical fiber under measurement based on these pieces of information.

Example embodiments describe an optical line terminal, OLT, configured to perform determining a fragmentation allocation for respective ONUs; and notifying, the respective ONUs, of the fragmentation allocation. Other example embodiments relate to an optical network unit, ONU, configured to perform receiving, from the OLT, fragmentation allocation for fragmenting one or more packets; processing the packets in accordance with the fragmentation allocation to obtain fragmented and unfragmented packets; and forwarding, to the OLT, the fragmented and unfragmented packets in accordance with the dynamic upstream allocation map.