A method and system is described. A signal indicative of a failure of a first channel within a plurality of channels of a transmission signal traversing a signal working path in a network is received. The signal working path has a headend node, a tail-end node and an intermediate node. The first channel has a frequency band and a power level prior to failing. The signal working path is associated with a protection path. The protection path includes the intermediate node, optical cross-connects, and a transmitter supplying (ASE) light. The transmitter is activated to supply the ASE light within a frequency band and having a power level corresponding to the frequency band and power level associated with the first channel. The ASE light is supplied to a cross-connect, such that the cross-connect provides a transmission signal including the ASE light.

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 method for processing low-rate service data, an apparatus, and a system, where the method includes: mapping low-rate service data into a newly defined low-rate data frame, where a rate of the low-rate data frame matches a rate of the low-rate service data, the data frame includes an overhead area and a payload area, the payload area is used to carry the low-rate service data, a rate of the payload area in the low-rate data frame is not less than the rate of the low-rate service data, and the rate of the low-rate service data is less than 1 Gbps; mapping the low-rate data frame into one or more slots in another data frame, where a rate of the slot is not greater than 100 Mbps; mapping the other data frame into an optical transport unit (OTU) frame; and sending the OTU frame.

Disclosed are an apparatus and testing methods for performing testing operations over multiple types of links and through multiple potential points of failure to segment sources of problems, which may relate to reported or actual instances of service disruption in a network communication environment. The apparatus may perform service layer testing directly via an optical link, in addition to via Ethernet service layer testing. The apparatus may further conduct tests on other layers as well, including the physical layer, the network layer, and the link layer. To facilitate efficient testing, the apparatus may integrate programmable workflow profiles that specify tests to be conducted, and may interface with a cloud platform for sharing results of the tests, providing end-to-end testing of various components and types of links (whether optical or electrical, including wired and wireless links). Results of the tests may provide guidance to resolve detected problems.

In a monitoring system using optical fibers, an area to be monitored is divided into zones where each zone has fibers which create a change in a signal transmitted by the fiber in response to an event to be monitored. The fibers all communicate to a common monitoring system having a channel for each zone. The fiber of a second one of the zones communicates to the respective channel of the common monitoring system through a fiber passing through a first one of the zones so that the fiber and thus the second channel is also responsive to an event in the first zone zones. The invention provides a method of distinguishing between the separate zones where events have occurred by a Boolean analysis of the signals in the different channels.

The invention provides a protection method against failure of AI-based QoT prediction, comprising calculating a first number of frequency slots and a consumable margin for a working lightpath that meet the traffic demand according to a method for allocating an OSNR margin for a working lightpath; calculating a second number of frequency slots and a consumable margin for the protection lightpath that meet the traffic demand according to a method for allocating an OSNR margin for the protection lightpath; and evaluating utilization of spectrum resource based on the first number of frequency slots and the second number of frequency slots and evaluating reliability of lightpath based on the consumable margin for the working lightpath. The method of the invention is more stable in practical network applications.

A method for processing low-rate service data, an apparatus, and a system, where the method includes: mapping low-rate service data into a newly defined low-rate data frame, where a rate of the low-rate data frame matches a rate of the low-rate service data, the data frame includes an overhead area and a payload area, the payload area is used to carry the low-rate service data, a rate of the payload area in the low-rate data frame is not less than the rate of the low-rate service data, and the rate of the low-rate service data is less than 1 Gbps; mapping the low-rate data frame into one or more slots in another data frame, where a rate of the slot is not greater than 100 Mbps; mapping the other data frame into an optical transport unit (OTU) frame; and sending the OTU frame.

[Problem] In an optical transmission system, a position and a cause of a failure are identified while avoiding tightness of processing on a network controller side.

[Solution] An optical transmission system 1 includes a plurality of nodes 4i to 4k interconnected by an optical transmission line, a plurality of node controllers 3i to 3k that detect degradation of signal quality at the nodes 4i to 4k, respectively, and determine a degradation mode correlated with the signal quality, and a network controller 2 that identifies a node or a component in which failure has occurred based on a node for which the node controller 3i to 3k has detected degradation of the signal quality, the degradation mode, a network topology formed of the nodes, and an optical path set between the nodes.

A method for providing tests and measurements using a transceiver is disclosed. In some examples, the method may involve using, at least one test instrument and at least one transceiver, to perform tests and measurements at a testing point in a network. The tests and measurements may include at least one of: (1) channel or wavelength and data measurements; (2) insertion loss and optical power measurements; or (3) bit error rate (BER) measurements.

The invention relates to a method for migrating data traffic from an existing optical WDM transmission system to a new optical WDM transmission system, the existing optical WDM transmission system using a first optical transmission band and the new optical WDM transmission system being capable of using a second optical transmission band. The second optical transmission band at least partially includes the first optical transmission band and a further extension band that does not overlap with the first optical transmission band, the method including the steps of. According to the invention, a migration filter device is used in order to connect, during a migration phase, the network nodes of the existing system and the network nodes of the new system to the network paths that have been used by the existing system. During the migration phase, both systems are operated in parallel, with the new system using the extension band only. In this way, during the migration phase, the data traffic handled by the existing system can stepwise be switched to the new system. After all data traffic has been switched to the new system, the existing system can be deinstalled. The migration filter devices can stepwise be deinstalled.