A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

A data communication network includes a network node and a processor. The network node includes an optical link and a reflectometry analyzer to provide a plurality of reflectometry results, each reflectometry result providing a characterization of physical and operational properties of the optical link at the time of the reflectometry result. The processor receives a first set of the reflectometry results, and calculates a federated fingerprint of the physical and operational properties of the optical link based on the plurality of fingerprints in first set of the reflectometry results. The federated fingerprint is a combination of fingerprints from every section of the optical link. The processor receives a second set of the reflectometry results, and compares each of a plurality of fingerprints in the second set of reflectometry results with a respective corresponding fingerprint in the federated fingerprint. The processor determines whether a physical tampering of the optical link has occurred based upon the comparison.

Provided are methods, apparatuses and a system for monitoring a Reconfigurable Optical Add Drop Multiplexer (ROADM) optical network. The method includes: loading, in an optical signal at a sending end, a wavelength label frequency and attribute information of a channel used for transmitting the optical signal; sending the wavelength label frequency and/or the attribute information; receiving, at a monitoring end, the optical signal and acquiring, from the optical signal, the wavelength label frequency and/or the attribute information of the channel used for transmitting the optical signal; and monitoring the ROADM optical network according to the wavelength label frequency and/or the attribute information. The technical solution solves the technical problem in related art that the ROADM optical network cannot be effectively monitored, and achieves the effective monitoring of the ROADM optical network.

The present invention discloses: when a first laser in N lasers is switched to a second idle laser in M lasers, a wavelength of a wavelength-selective optical element to which the first laser is coupled is adjusted from a first wavelength to a second wavelength, and the second wavelength is different from the N wavelengths. Similarly, when a first optical receiver in N optical receivers is switched to a second idle optical receiver in M optical receivers, a wavelength of a wavelength-selective optical element to which the first optical receiver is coupled is adjusted from a first wavelength to a second wavelength, and the second wavelength is different from the N wavelengths.

A transmission method and system for an optical burst transport network are disclosed in the present document. The method includes: acquiring a topology of a mesh OBTN network, and generating one or more logical sub-networks according to the topology of the mesh OBTN network; a predetermined master node in the mesh OBTN network updating bandwidth maps for all logical sub-networks; the predetermined master node is a node, which all control channels pass through, in all the nodes of the mesh OBTN network.

A performance monitor configured to unify at least two different signal-quality estimates into a single performance metric such that a systematic error associated with the performance metric can be approximately constant or smaller than a specified fixed limit over a significantly wider range of data-link conditions than that of a conventional performance metric of similar utility. In an example embodiment, the performance metric can be based on a weighted sum of two different SNR estimates, obtained from an error count of the receiver's FEC decoder and from a constellation scatter plot generated using the receiver's symbol decoder, respectively. Different weights for the weighted sum may be selected for different data-link conditions, e.g., using SNR thresholding, analytical formulas, or pre-computed look-up tables. The performance metric may be supplied to a control entity and considered thereby as a factor in a possible decision to trigger protective switching and/or a transponder-mode change.

Systems and methods for collecting information regarding optical connections in an FDH are disclosed. An example FDH includes: a bulkhead having a plurality of passive optical couplers, each of the plurality of passive optical couplers having a respective first port adapted to receive an end of a respective first optical fiber, a respective second port adapted to receive an end of a respective second optical fiber, and a respective passive optical activity indicator configured to expose (i) a portion of first light propagating in the respective first optical fiber when the first optical fiber is received in the first port, and (ii) a portion of second light propagating in the respective second optical fiber when the second optical fiber is received in the second port; and an image sensor configured to capture one or more images of the respective passive optical activity indicators of the plurality of passive optical couplers.

A device may receive health information associated with a network circuit included in an optical network. The device may determine, based on the health information and network circuit information associated with the network circuit, that the network circuit is experiencing a health issue. The device may identify a diagnostic technique to be applied to the network circuit based on determining that the network circuit is experiencing the health issue. The device may automatically and iteratively apply the identified diagnostic technique to the network circuit in order to identify a fault location. The device may determine a corrective action, associated with the network circuit, based on the fault location and the health issue. The device may provide information associated with the corrective action to cause the corrective action to be taken.

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive data and provide a plurality of electrical signals based on the data; and a modulator operable to modulate the optical signal to provide a plurality of optical subcarriers based on the plurality of electrical signals. One of the plurality of subcarriers carries first information indicative of a first portion of the data in a first time slot and second information indicative of a second portion of the data in a second time slot. The first information is associated with a first node remote from the transmitter and the second information is associated with a second node remote from the transmitter. A receiver as well as a system also are described.

An optical network node capable of being powered, comprising—a reflector arranged to reflect an optical signal, and—a switch arranged to direct the optical signal to the reflector in dependence on whether the optical network node is powered.