CN114285465A

CN114285465A - Optical transmission network, noise loading and noise clearing method

Info

Publication number: CN114285465A
Application number: CN202111555241.9A
Authority: CN
Inventors: 王磊; 张欢; 王春晓; 谢崇进
Original assignee: Alibaba China Co Ltd
Current assignee: Alibaba China Co Ltd
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-04-05

Abstract

The embodiment of the application provides an optical transmission network, a noise loading method and a noise clearing method. In the embodiment of the application, the network element controller is used as a control unit for channel noise loading to process the channel noise loading of the local network element, and compared with a centralized management unit used as a control unit for channel noise, the method and the system can reduce the signal stream transmission flow, are favorable for improving the timeliness of the channel loading, and are further favorable for improving the system stability.

Description

Optical transmission network, noise loading and noise clearing method

Technical Field

The present application relates to the field of optical communications technologies, and in particular, to an optical transmission network, a noise loading method, and a noise removing method.

Background

Optical transmission networks may multiplex multiple transmission channels onto a single optical fiber using wavelength combining techniques known as Wavelength Division Multiplexing (WDM) or Dense Wavelength Division Multiplexing (DWDM). For WDM or DWDM optical transmission networks, noise filling techniques are used to load noise onto idle or unused channel usage channels, so that the system performance of the optical transmission network is relatively stable. When the optical transmission network fails, the noise loading speed of the failed channel greatly affects the stability of the network system. Therefore, how to improve the channel noise loading of the optical transmission network becomes a technical problem of continuous research in the field.

Disclosure of Invention

Aspects of the present application provide an optical transmission network, a noise loading method, and a noise removing method, so as to improve a channel noise loading speed and improve stability of the optical transmission network.

An embodiment of the present application provides an optical transmission network, including: a plurality of network elements and a plurality of network element controllers corresponding to the plurality of network elements respectively; the network element controllers are in communication connection with the corresponding network elements; said plurality of network elements are optically connected;

the network element controller is used for: determining a failed optical link upon sensing a failure of the optical transport network; determining a target channel influenced by the fault optical link from a target network element corresponding to the network element controller; and controlling the target network element to carry out noise loading on the target channel.

The embodiment of the present application further provides a noise loading method, which is applicable to a cell controller, and includes:

determining a failed optical link in an optical transport network upon sensing a failure of the optical transport network;

determining a target channel influenced by the fault optical link from a target network element corresponding to the network element controller;

and controlling the target network element to carry out noise loading on the target channel.

The embodiment of the present application further provides a noise removing method, including:

recording a target channel loaded by noise in a target network element when an optical transmission network fails;

and controlling the target network element to carry out noise removal on the target channel under the condition of sensing the fault recovery of the optical transmission network.

In the embodiment of the application, the network element controller is used as a control unit for channel noise loading to process the channel noise loading of the local network element, and compared with a centralized management unit used as a control unit for channel noise, the method and the system can reduce the signal stream transmission flow, are favorable for improving the timeliness of the channel loading, and are further favorable for improving the system stability.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 and fig. 2 are schematic structural diagrams of an optical transmission network provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a ROADM provided in an embodiment of the present application;

fig. 4 is a schematic diagram illustrating a channel noise loading process when an optical link between network elements fails in an optical transmission network according to an embodiment of the present application;

fig. 5 is a schematic diagram of a channel noise loading process when an optical link failure occurs in a network element in an optical transmission network according to an embodiment of the present application;

fig. 6 is a schematic diagram of a channel noise loading process when an uplink optical link failure occurs in an optical transmission network according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of another optical transmission network according to an embodiment of the present application;

fig. 8 is a schematic flowchart of a noise loading method according to an embodiment of the present application;

fig. 9 is a schematic flowchart of a noise removal method according to an embodiment of the present application;

fig. 10 is a schematic flowchart of a noise loading method in case of an optical link failure between network elements according to an embodiment of the present application;

fig. 11 is a schematic flowchart of a noise removal method when an optical link between network elements fails according to an embodiment of the present application;

fig. 12 is a schematic flowchart of a method for loading noise when an optical link in a network element fails according to an embodiment of the present application;

fig. 13 is a schematic flowchart of a noise removal method when an optical link in a network element fails according to an embodiment of the present application;

fig. 14 is a schematic flowchart of a noise loading method in case of an optical link failure between network elements according to an embodiment of the present application;

fig. 15 and fig. 16 are schematic flowcharts of a noise removing method in case of an optical link failure between network elements according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

For WDM or DWDM optical transmission networks, noise filling techniques are used to load noise onto idle or unused channel usage channels, so that the system performance of the optical transmission network is relatively stable. When the optical transmission network fails, the noise loading speed of the failed channel greatly affects the stability of the network system. Therefore, how to improve the channel noise loading of the optical transmission network becomes a technical problem of continuous research in the field.

In some embodiments of the present application, the cell controller is used as a control unit for channel noise loading to process channel noise loading of a local cell, and compared with a centralized management unit used as a control unit for channel noise, the cell controller can reduce a signal stream transmission flow, thereby being beneficial to improving timeliness of channel loading and further being beneficial to improving system stability.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be noted that: like reference numerals refer to like objects in the following figures and embodiments, and thus, once an object is defined in one figure or embodiment, further discussion thereof is not required in subsequent figures and embodiments.

Fig. 1 is a schematic structural diagram of an optical transmission network according to an embodiment of the present application. As shown in fig. 1, the optical transmission network may include: a plurality of network elements 10. Plural means 2 or more. Fig. 1 is only illustrated with the number of network elements 10 being 3, but is not limiting. A plurality of network elements 10 are optically connected. In the embodiment of the present application, the optical connection may be a connection through any optical link, for example, a connection through an optical fiber, a connection through an optical waveguide, or a connection through spatial optical coupling, but is not limited thereto.

In the embodiment of the present application, an optical amplifier (shown as a triangle in fig. 1), a dispersion compensation device (not shown in the drawings), and the like may also be disposed on the optical link. When the optical link is normal, the optical amplifier amplifies an optical signal in the optical link by converting energy of pump light into energy of signal light based on stimulated radiation of laser. In the event of a failure of an optical link, the optical amplifier downstream of the failed optical link may automatically shut down the pump light, thereby automatically shutting down the optical amplifier.

In the embodiment of the present application, the Optical Amplifier may be an Erbium-doped Fiber Amplifier (EDFA) or a Semiconductor Optical Amplifier (SOA), but is not limited thereto.

In this embodiment, the network element 10 refers to a network element in an optical transmission network, and may include: 1 or more optical transmission devices. The plurality of units means 2 or more than 2 units. In the embodiment of the present application, the optical transmission devices in the same network element 10 may be provided by the same manufacturer, or may be provided by different manufacturers. Preferably, the optical transmission devices in the same network element 10 are provided by different vendors. The optical transmission equipment in different network elements 10 may be provided by the same vendor or by different vendors.

In practical application, in order to realize the good-bad complementation between different manufacturers, the optical transmission equipment in the network element 10 can be provided by a plurality of manufacturers, so that the decoupling between an optical transmission network and the manufacturers can be realized, the software and hardware technical barrier of the hardware of the optical transmission equipment manufacturers is broken, the optical transmission software and hardware decoupling, the photoelectric decoupling and the optical layer dimension decoupling are realized on the basis of a standardized transmission function module and a data model, and the multi-manufacturer technical advantage combination and the hybrid networking are realized.

Since the control logic and the management mode of the optical transmission device are different for different manufacturers, a cell controller 20 may be correspondingly provided for each cell 10, as shown in fig. 1. Each network element corresponds to one or more network element controllers 20; and is communicatively coupled to its corresponding cell controller 20. There is an independent corresponding cell controller 20 for each network element 10.

The connection between the network element controller 20 and the corresponding network element 10 may be wireless or wired. Optionally, the network element 10 may be communicatively connected to the corresponding controller 20 through a mobile network, and accordingly, the network format of the mobile network may be any one of 2G (gsm), 2.5G (gprs), 3G (WCDMA, TD-SCDMA, CDMA2000, UTMS), 4G (LTE), 4G + (LTE +), 5G, WiMax, and the like. Optionally, the network element 10 may also be communicatively connected to its corresponding network element controller 20 by bluetooth, WiFi, infrared, or the like.

The network element controller 20 may also be referred to as a network element management unit, which is used to manage and control the optical transmission equipment within the local network element. In the embodiment of the present application, the implementation form of the cell controller 20 is not limited. Alternatively, the network element controller 20 may be implemented as any device or apparatus having communication and control processing functions, such as a single server device, a cloud server array, or a Virtual Machine (VM) running in the cloud server array; or, the device may also refer to other computing devices with corresponding service capabilities, such as a terminal device (running a service program) such as a computer.

In the present embodiment, the optical signal band that can be supported by the optical transmission network is not limited. For example, the optical transport network may support the C-band, L-band, or C + L-band, among others. In practical application, for an optical transmission network, channels corresponding to some bands have optical signals carrying information, which indicates that the channels are used channels; some of the channels corresponding to the bands are in an unused state or idle state.

Since optical signals of different wavelength bands generate linear and nonlinear effects when transmitted in a channel, the linear and nonlinear effects greatly affect the stability of an optical transmission network. If there is no optical signal transmission in the unused or idle channel, in some cases, it is necessary to use the idle channel to load the optical signal in the idle channel. The transient effects that occur for an optical channel can affect other used channels, affect the stability of other channels, and thus affect the stability of the optical transport network. Therefore, the noise filling technology can be adopted to load the noise signal on the idle or unused channel using channel, so that the optical signal carrying information is loaded to replace the noise signal when the idle channel needs to be used, and the transient effect cannot be generated, therefore, the influence on other channels can be reduced, and the system performance of the optical transmission network is relatively stable. Wherein, the channel noise loading refers to loading a noise signal to a channel.

Based on the above analysis, in the embodiment of the present application, as shown in fig. 1, a noise signal, such as spontaneous emission noise (ASE) noise, may be loaded to an idle channel of the optical transmission network. The noise signal transmitted by the idle channel may cover the communication frequency band supported by the idle channel, but not cover the communication frequency band supported by the channel used by the optical transmission network. For example, assuming that the entire communication frequency band of the optical transmission network is the C + L band, in fig. 1, the channels used by the optical transmission network are MC1-MC 4; accordingly, the spectrum of the noise signal transmitted by the idle channel covers other frequency bands in the C + L band except for the communication frequency bands supported by the MC1-MC 4.

In the process of using the optical transmission network, an optical transmission network fault sometimes occurs, for example, a certain optical link or some optical links are broken, and in order to maintain the stability of the optical transmission network, noise loading needs to be performed on channels supported by the faulty optical link. The speed of noise loading of a failed channel greatly affects the stability of the network system.

In the embodiment of the present application, in order to increase the noise loading speed of the fault channel, channel noise loading in the local network element may be implemented by the network element controller 20. The local network element refers to a network element communicatively connected to the network element controller 20. For example, in fig. 1, the local network element of the network element controller 20 numbered a is the network element 10 numbered NE-a; the local network element of the network element controller 20 numbered B is the network element 10 numbered NE-B. The following provides an exemplary description of the noise loading manner provided in the embodiments of the present application.

In this embodiment, the cell controller 20 may sense a state of the optical transmission network, and in a case where a failure of the optical transmission network is sensed, determine a failed optical link; determining a target channel affected by the failed optical link from a target network element corresponding to the network element controller 20; and then, the target network element can be controlled to carry out noise loading control on the target channel, so that the frequency spectrum of the noise signal loaded by the target channel has the same frequency range as the communication frequency band of the channel, and the channel noise loading of the local network element by the network element controller is realized.

In the embodiment of the present application, a specific implementation form of the device for providing the noise signal is not limited. In some embodiments, the noise signal may be provided by a noise source, or spontaneous emission noise generated by a pump source of the optical amplifier, or the like.

In this embodiment, the cell controller is used as a control unit for channel noise loading to process channel noise loading of the local cell, and compared with a centralized management unit used as a control unit for channel noise, the cell controller can reduce a signal stream transmission flow, thereby being beneficial to improving timeliness of channel loading and further being beneficial to improving system stability.

In the embodiment of the present application, the specific implementation form of the network element 10 is not limited. The channel noise loading method provided in the embodiment of the present application is specifically described below with reference to a specific network element structure.

In some embodiments, as shown in fig. 2, each network element 10 comprises: a Reconfigurable Optical Add-Drop Multiplexer (ROADM) 101. Each optical transmission device in the network element 10 may comprise a ROADM 101. In this embodiment, a plurality of network elements 10 may be optically linked through a ROADM 101. ROADM101 may perform Add/Drop of optical channels and cross-scheduling of wavelength levels between through optical channels on one network element node. The optical channel add-on refers to loading an optical signal onto an optical link, that is, adding the optical signal from an optical transmitter to an optical transmission network; drop means that the optical signal is dropped from the optical transmission network to the optical receiver, i.e. the optical signal is sent out from the optical transmission network.

In this embodiment, as shown in fig. 2, the ROADM101 includes: at least one external Wavelength Selective Switch (WSS) module 101a and an Add/Drop Group (ADG) 101 b. The external WSS module 101a and the add-drop unit 101b are optically connected. In the present embodiment, the ADG 101b refers to a module, a device, or an apparatus that performs a drop of an optical signal transmitted in an optical transmission network and an add of the optical signal to the optical transmission network. The "outward" in the outward WSS module 101a may be understood as: and transmitting or receiving optical signals to other ROADMs except the ROADM to which the WSS module belongs.

In the present embodiment, the add/drop unit 101b is optically connected to the optical transmitter and the optical receiver. Specifically, the ADG 101b is optically connected to the optical transmitter via an add optical link (e.g., an optical link pointing to the ADG in MC1-MC4 in fig. 2) for receiving the optical signal sent by the optical transmitter; and transmits the optical signal to the external WSS module 101a through an optical link with the external WSS module 101 a. The ADG 101b also receives the optical signals transmitted by the external WSS module 101a and drops the optical signals to the optical receiver via a drop optical link (e.g., the optical link facing away from the ADG in MC1-MC4 in fig. 2).

In the present embodiment, the external WSS module 101a may be optically connected to external WSS modules in other ROADMs via optical links. Accordingly, the external WSS module 101a may transmit an optical signal to the external WSS module in the other ROADM through an optical link with the external WSS module in the other ROADM.

For ROADM101 includes: in the case of multiple external WSS modules 101a, each external WSS module 101a is optically connected to an ADG 101 b; and each two external WSS modules 101a are optically connected. Each external WSS module 101a is also optically connected to an external WSS module in another RAODM via an optical link.

Further, as shown in fig. 2, the external WSS module 101a includes: inlet WSS (denoted as WSS-I)_i) And an outlet WSS (denoted as WSS-E)_i). Wherein i is 1,2, …, n. n is a positive integer. In FIG. 2 onlyn is 4, but not limited to. For any two external WSS modules in the same ROADM, the tributary port (TRIB) of the ingress WSS of one external WSS module is optically connected to the tributary port (TRIB) of the egress WSS of the other external WSS module. For example, the ingress WSS (WSS-I) in FIG. 2₂) With the exit WSS of another external WSS module (WSS-E)₃) Is optically connected to the tributary port 1. The common port (COMM) of each ingress WSS is optically connected to the common port (COMM) of an egress WSS in another network element for receiving optical signals transmitted by the other network element. For example, the common port (COMM) of the ingress WSS in network element 10 numbered NE-B in FIG. 2 is optically connected to the common port (COMM) of the egress WSS in network element 10 numbered NE-A and network element 10 numbered NE-C, respectively. Accordingly, the common port (COMM) of each egress WSS is optically connected to the common port (COMM) of the ingress WSS of the other network element for transmitting optical signals to the other network element 10. For example, the common port (COMM) of the egress WSS in network element 10 numbered NE-B in FIG. 2 is optically connected to the common port (COMM) of the ingress WSS in network element 10 numbered NE-A and network element 10 numbered NE-C, respectively.

In the present embodiment, the tributary port (TRIB) of the inlet WSS and the tributary port (TRIB) of the outlet WSS are optically connected to the add-drop unit 101 b. Specifically, the tributary port (TRIB) of the ingress WSS is optically connected to a port corresponding to the drop optical link of the add-drop unit 101b, and is configured to transmit the optical signal output by the tributary port (TRIB) to the optical receiver through the drop optical link. For example, in FIG. 2, ingress WSS (WSS-I)₃) The tributary port 3 of the ADG 101b is optically connected to a port corresponding to the downstream optical link, and is configured to transmit the optical signal output by the tributary port 3 to the optical receiver through the downstream optical link. The tributary port (TRIB) of the egress WSS is optically connected to a port corresponding to the upstream optical link of the upstream and downstream unit 101b, and is configured to receive an optical signal transmitted by the upstream optical link. For example, in FIG. 2, the egress WSS (WSS-E)₂) The tributary port 3 of the add-drop unit 101b is optically connected to a port corresponding to the add optical link, and is configured to receive an optical signal transmitted by the add optical link.

In the embodiment of the present application, the specific implementation form of the ADG 101b is not limited. In some embodiments, the ADG 101b may include, as shown in the ROADM schematic diagram of fig. 3: local WSS module 101 c. The local WSS module 101c may include: an inbound WSS101c 1 and a outbound WSS101c 2. The common port (COMM) of the add WSS101c 1 is optically connected to the add optical link, and is configured to receive an optical signal transmitted by the add optical link. The common port (COMM) of the downstream WSS101c2 is optically connected to the downstream optical link for transmitting optical signals in the optical transmission network to the downstream optical link.

Further, for the upper optical link of the local WSS module 101c, the common port (COMM) COMM of the upper WSS101c 1 is connected to the optical combiner 101c3, which is used to combine the optical signals received from the optical receiver and send them to the upper WSS101c2, and then the upper WSS101c2 forwards them to the branch port (TRIB) of the exit WSS of the external WSS module 101a via the optical link, thereby implementing wavelength division multiplexing of the optical link. Optionally, an optical amplifier 101c4 is further connected between the common port (COMM) of the upper WSS101c2 and the optical combiner 101c3, for performing power amplification on the combined optical signal, and compensating for a loss caused by the upper WSS101c2, the optical combiner 101c3, and an optical link therebetween.

For the drop WSS101c2 in the local WSS module 101c, its tributary port (TRIB) is optically linked with the tributary port (TRIB) of the ingress WSS of the external WSS module 101 a; the optical splitter 101c5 is connected to the common port (COMM). The drop WSS101c2 may receive the optical signal output from the branch port (TRIB) of the inlet WSS of the external WSS module 101a, and output the optical signal to the optical splitter 101c5 after performing wavelength selection on the optical signal; the optical splitter 101c5 is used to perform power average distribution on the optical signal output by the drop WSS101c2, and then output the optical signal to the optical receiver.

The optical splitter 101c5 may be a 1 × N optical coupler, where N represents the number of output ends of the optical coupler, and the specific value thereof may be flexibly set according to the number of optical receivers. Further, an optical amplifier 101c6 is connected between the common port (COMM) of the drop WSS101c2 and the optical splitter 101c5, and is configured to perform power amplification on the optical signal output by the drop WSS101c2, and output the optical signal after power amplification to the optical splitter 101c5, so as to compensate for losses caused by the drop WSS101c2, the optical splitter 101c5, and an optical link therebetween.

Optionally, for each external WSS module 101a, the common port (COMM) COMM of its ingress WSS and egress WSS 20b2 is connected with an optical amplifier (shown as a triangle in fig. 2 and 3). The optical amplifier connected with the inlet WSS is used for performing power amplification on an optical signal received from the optical link, compensating the line loss caused by the optical link and transmitting the optical signal after power amplification to the inlet WSS; the optical amplifier connected to the common port of the egress WSS in the external WSS module 101a is used to perform power amplification on the optical signal output by the egress WSS, and is used to compensate for the loss caused by the egress WSS and the optical link inside the ROADM. Alternatively, an optical amplifier connected to a common port (COMM) of an egress WSS in the external WSS module 101a may amplify the optical signal to a required power level, and then send the power-amplified optical signal to an optical link for transmission to an ingress WSS in another network element connected to the egress WSS.

The implementation form of the ADG 101b is merely an example and is not limited.

In the embodiment of the application, each WSS can forward the specified wavelength from the specified input port to the specified output according to actual needs, so as to realize a wavelength forwarding function, and each WSS also has a function of power balance among wavelengths. The complexity of a WSS is determined by the number of wavelengths that can be reconfigured and the number of input and output ports.

The inlet WSS can be understood as a band de-aggregator, which can separate an optical signal received by a common port (COMM) of the inlet WSS into optical signals of multiple bands; and outputs optical signals of different wavelength bands from a designated tributary port (TRIB). The outlet WSS may be understood as a band aggregator that aggregates optical signals of multiple bands received by a tributary port (TRIB) of the outlet WSS; and outputs the aggregated optical signal from its common port (COMM). The aggregated optical signal covers multiple bands.

The above description is only illustrative of the structure of the optical transmission network provided in the embodiments of the present application, and does not mean that the optical transmission network must include all the devices shown in fig. 2 and 3, nor does the optical transmission network include only the components shown in fig. 2 and 3.

In order to improve the relative stability of the system performance of the optical transmission network, in the embodiment of the present application, as shown in fig. 2, a noise signal, such as spontaneous emission noise (ASE) noise, may be loaded on an idle channel of the optical transmission network. The noise signal transmitted by the idle channel may cover the communication frequency band supported by the idle channel, but not cover the communication frequency band supported by the channel used by the optical transmission network. For example, assuming that the entire communication frequency band of the optical transmission network is the C + L band, in fig. 2, the channels used by the optical transmission network are MC1-MC 4; accordingly, the spectrum of the noise signal transmitted by the idle channel covers other frequency bands in the C + L band except for the communication frequency bands supported by the MC1-MC 4.

In the embodiment of the present application, as shown in fig. 2, a noise signal may be loaded on an idle branch port (e.g., branch port 4) of the outlet WSS of the external WSS module 101 a. The idle branch port refers to a branch port that is not connected to other devices in the WSS, such as branch ports 2 and 4 shown in fig. 2. In practical engineering applications, a certain branch port of the outlet WSS may be designated as a port loaded with a noise signal. The egress WSS may establish a Media Channel (MC) between the noise-loaded tributary port (TRIB) and the common port (COMM), and configure a communication band of the MC to cover a communication band of an idle channel in the optical transmission network, but not include a communication band supported by a channel already used by the optical transmission network. Thus, the outlet WSS can carry out wave band aggregation on the noise in the optical transmission medium channel and the optical signals transmitted by other optical transmission medium channels; and outputting the aggregated optical signal to an optical link connected with other network elements, thereby realizing the noise loading of an idle channel.

In this embodiment, the cell controller 20 may sense a state of the optical transmission network, determine a channel affected by a failure when sensing the failure of the optical transmission network, and perform noise loading control on the channel affected by the failure, so that a frequency spectrum of a noise signal loaded on the channel affected by the failure has the same frequency band range as a communication frequency band of the channel.

In the embodiment of the present application, a specific implementation form in which the cell controller 20 senses the state of the optical transmission network is not limited. In some embodiments, a fault monitoring unit (not shown in the figures) is provided on an optical link of the optical transmission network. In the embodiment of the present application, the specific arrangement position and number of the fault monitoring units are not limited. Alternatively, a plurality of fault monitoring units may be provided according to the actually monitored spatial granularity. For example, a fault monitoring unit may be provided on each optical link of the optical transmission network. The fault monitoring unit is used for monitoring the power of the optical link; and under the condition that the detected light power is less than or equal to the set power threshold, providing a non-light warning (LOS) to the network element controller corresponding to the target network element to which the fault monitoring unit belongs. Correspondingly, the network element controller corresponding to the target network element determines that the optical transmission network fault is sensed under the condition that no light warning is received.

In the embodiment of the present application, a specific implementation form of the fault monitoring unit is not limited. In some embodiments, the fault monitoring unit may be an optical power monitor. The optical power monitor can directly monitor the optical power of the optical link where the optical power monitor is located. In other embodiments, the fault monitoring unit may be an Optical Channel Monitor (OCM). The optical channel monitor is used for performing spectrum scanning on an optical link where the optical channel monitor is located to obtain scanned spectrum power; the optical link is power monitored using spectral power. Further, when the scanned spectral power is less than or equal to the set power threshold, a no light alarm is sent to the cell controller 20 corresponding to the target cell. The cell controller 20 corresponding to the target cell can determine that the optical transmission network has a fault when receiving no light warning.

In the embodiment of the present application, it is not limited which optical links deploy the optical power monitor, and which optical links deploy the optical channel monitor. Optionally, the optical power monitor may be deployed at an intermediate transmission link in an optical transmission network; an optical channel monitor is deployed at the add optical link of ADG 101 b. Of course, optical power monitors may also be deployed at the add optical link of the ADG 101 b.

Further, the cell controller 20 may determine a failed optical link. In some embodiments, the non-light warning includes an identification of the monitored unit. The monitored unit is a device or equipment monitored by the fault monitoring unit. The identifier of the monitored unit refers to information that can uniquely identify one monitored unit, such as a monitored device identifier and a port number. The monitored device identifier may be a device name or an IP address of the device.

The network element controller 20 stores topology information of the optical transmission network in advance. Wherein the topology information of the optical transmission network includes: the optical transmission network includes names, identifications, ports and connection relationships between the ports of the devices. The connection relationship between the devices can be expressed by the identification, name and port number of the devices. For example, the connection relationship between devices can be expressed as the common port (COMM) of a WSS identified as X being optically connected to the input of an optical amplifier identified as Y, and so on. Based on the topology information of the optical transmission network, the network element controller 20 can obtain the identifier of the monitored unit from the lightless warning when determining the faulty optical link; and determining a fault optical link according to the identification of the monitored unit and the pre-stored topological structure information of the optical transmission network. For example, the optical link sending the transmission optical signal to the monitored unit may be determined as a faulty optical link according to the identification of the monitored unit and the topology information of the optical transmission network.

In some embodiments, as shown in FIG. 4, WSS (WSS-I) may be at the ingress of network element 10_i) A fault monitoring unit is deployed on an optical link corresponding to the common port (COMM); the fault monitoring unit is used for monitoring an inlet WSS (WSS-I)_i) Of the input optical power of (1). WSS (WSS-I) at the ingress of a network element 10_i) The deploying the fault monitoring unit on the optical link corresponding to the common port (COMM) of (a) may include: at the entrance of WSS (WSS-I)_i) Or a WSS (WSS-I) at the entrance of the network element 10_i) A fault monitoring unit is deployed at the common port (COMM), etc. Wherein the entrance of the optical amplifier is optically connected with the common port (COMM) of the exit WSS in the upstream network element; optical amplifier egress and ingress WSS (WSS-I)_i) Is optically connected to the common port (COMM).

For the fault monitoring unit, the common port (COMM) of the ingress WSS) When the optical link with other network elements fails, the failure monitoring unit can trigger a non-light alarm. Based on this, in the case that the identifier of the monitored unit includes the common port (COMM) of the entry WSS of the target network element, the network element controller 20 may determine the upstream network element connected to the entry WSS of the target network element according to the topology information of the optical transmission network; and determining an optical link connected between the upstream network element and the target network element as a fault optical link. For example, as shown in FIG. 4, the identity of the monitored unit includes the ingress WSS (WSS-I) of number NE-B₂) Common port (COMM). Further, the cell controller 20 may determine an ingress WSS (WSS-I) according to topology information of the optical transmission network₂) The connected upstream network element is network element 10 numbered NE-a. Further, it may be determined that the optical link connected between the network element 10 numbered NE-a and the network element 10 numbered NE-B is a failed optical link.

In other embodiments, as shown in fig. 5, WSS (WSS-E) may be egress from the network element 10_i) A fault monitoring unit is deployed at the branch port; the fault monitoring unit is used for monitoring an export WSS (WSS-E)_i) The branch port (TRIB). Accordingly, in case of an optical link failure connected between an egress WSS and an ingress WSS within the same network element 10, or in case of an optical link failure between this network element and its upstream network element, the failure monitoring unit at the tributary port of the egress WSS triggers a non-optical warning. For example, as shown in FIG. 5, at the exit WSS (WSS-E)₃) Ingress WSS (WSS-I) within the same network element as it is₂) In the event of an optical link failure between, or at the ingress WSS (WSS-I)₂) Egress WSS (WSS-E) in case of failure of an optical link with a network element numbered NE-A₃) A fault monitoring unit deployed at the tributary port (TRIB) issues a lightless warning to the cell controller 20.

Because both the optical link fault in the network element and the optical link fault between the network elements can trigger the fault monitoring unit at the branch port (TRIB) of the egress WSS to send out the lightless warning, the network element controller 20 can perform the intra-network-element fault verification on the target network element under the condition that the monitored unit contained in the lightless warning contains the branch port (TRIB) of the egress WSS; and the result of the verification is the fault of the optical link in the target network elementUnder the condition, according to the topological structure information of the optical transmission network, determining an optical link in a target network element connected with a branch port (TRIB) of an exit WSS (wireless sensor network) and contained by no light warning; and determining the optical link in the target network element as a failed optical link. For example, as shown in FIG. 5, the exit WSS (WSS-E) is included in the absence of light warning₃) In the case of the tributary port 1, the cell controller 20 may determine an egress WSS (WSS-E) based on topology information of the optical transmission network₃) The optical link in the target network element connected to the branch port 1 is: export WSS (WSS-E)₃) And portal WSS (WSS-I)₂) An optical link therebetween; further, an egress WSS (WSS-E) may be determined₃) And portal WSS (WSS-I)₂) The optical link between them is a failed optical link.

In the embodiment of the present application, a specific implementation manner of performing fault checking in a network element is not limited. In some embodiments, the fault monitoring units may be deployed at both ends of the optical link within the network element, respectively. For example, for a tributary port (TRIB) of the ingress WSS and a tributary port (TRIB) of the egress WSS that are connected by an optical link in the same network element, a fault monitoring unit may be respectively provided at the tributary port (TRIB) of the ingress WSS and the tributary port (TRIB) of the egress WSS. When the optical link in the network element fails, the fault monitoring unit on the optical link connected with the branch port (TRIB) of the inlet WSS can still monitor the optical power and does not send out a lightless warning. In case of a failure of an optical link between network elements, a lightless warning is issued. Based on this, the cell controller 20 may determine the identity of the monitored unit that the no light warning contains, if the no light warning is received; and determining an optical link failure within the network element in case the monitored unit comprises a tributary port (TRIB) of the egress WSS but not of the ingress WSS.

Further, the cell controller 20 may determine the optical link connected to the monitored unit as a faulty optical link according to the topology information of the optical transmission network.

In still other embodiments, as shown in fig. 6, a failure monitoring unit may be deployed at the add port of the add/drop unit 101b of the network element 10, and the failure monitoring unit is used for the input optical power of the add port. Accordingly, when the upstream optical link fails, the failure monitoring unit at the upstream port of the upstream unit 101b triggers a no-light alarm. For example, as shown in fig. 6, when an uplink optical link in the MC4 channel of the add/drop unit 101b fails, the failure monitoring unit disposed at the uplink port of the add/drop unit 101b corresponding to the uplink optical link in the MC4 channel sends out a no light alarm to the cell controller 20.

Based on this, the network element controller 20 determines the uplink optical link connected to the uplink port according to the topological structure relationship of the optical transmission network when the monitored unit without the light alarm includes the uplink port of the uplink/downlink unit 101 b; and determining the up optical link connected with the port as a fault optical link.

For an optical transport network, an optical link failure does not affect the operation of the upstream optical transport equipment and the upstream optical link of the failed optical link, but may affect the optical transport of the downstream optical transport equipment and the downstream optical link. In each network element of the optical transmission network, the egress WSS is configured to transmit the optical signal to a downstream network element. For example, for the optical transport networks shown in FIGS. 4-6, the egress WSS (WSS-E) in network element 10 numbered NE-B₃) For transmitting the optical signal to a downstream network element, i.e. the network element numbered NE-C. In order to prevent the fault from being conducted downstream, the network element controller 20 may further determine, after determining the faulty optical link, a target egress WSS affected by the faulty optical link and a branch port (TRIB) of the target egress WSS affected by the faulty optical link from the target network element; further, the original channel of the tributary port (TRIB) of the target egress WSS affected by the failed optical link may be determined as the target channel.

Optionally, the network element controller 20 may determine a downstream egress WSS of the failed optical link according to the topology information of the optical transmission network; and determining the downstream outlet WSS as the target outlet WSS. Further, a tributary port (TRIB) on the target egress WSS connected to the failed optical link may be determined, which is the tributary port (TRIB) of the target egress WSS affected by the failed optical link.

For example, for the embodiment of an inter-network element optical link failure shown in fig. 4, it may be determined that the failed optical link is an optical link connected between network element 10 numbered NE-a and network element 10 numbered NE-B; further, a network element controller20 according to the topological structure information of the optical transmission network, determining the downstream exit WSS of the failed optical link as the serial number WSS-E₃The outlet WSS. Alternatively, the network element controller 20 may determine the downstream entry WSS of the failed optical link connection as number WSS-I according to the topology information of the optical transport network₂The inlet WSS of (1); further, an egress WSS connected to a tributary port (TRIB) of an ingress WSS numbered as WSS-I2 may be determined as a number WSS-E based on topology information of the optical transport network₃The outlet WSS; further, the number WSS-E can be determined₃The egress WSS of (b) is a downstream egress WSS of the failed optical link connection. Thus, WSS-E was determined₃The outlet WSS of (a) is the target outlet WSS. Accordingly, WSS-E may also be determined₃Tributary port 1 of the egress WSS and the ingress WSS is a tributary port affected by the failed optical link (TRIB).

For another example, for the embodiment of optical link failure in the network element shown in fig. 5, the downstream egress WSS of the failed optical link connection may be determined as the number WSS-E according to the topology information of the optical transport network₃The outlet WSS; and is determined as number WSS-E₃The outlet WSS of (1) is a target outlet WSS; and the branch port 1 of the target outlet WSS connected with the failed optical link is a branch port (TRIB) of the target outlet WSS affected by the failed optical link.

For another example, for the embodiment of the upstream optical link failure of the network element shown in fig. 6, the downstream egress WSS of the failed upstream optical link connection may be determined as the number WSS-E according to the topology information of the optical transport network₃And determines the downstream egress WSS (number WSS-E)₃The outlet WSS) is the target outlet WSS; further, the number WSS-E is determined₃The tributary port 3 connected to the failed upstream optical link on the egress WSS is a tributary port (TRIB) affected by the failed optical link on the target egress WSS.

Due to the fact that a branch port (TRIB) affected by the optical link on the target outlet WSS has no optical signal input, the optical link fault can be conducted downstream. In the embodiment of the present application, in order to improve the system stability, the network element controller 20 determines the target egress WSS affected by the failed optical link and the branch port (TRIB) of the affected target egress WSS; the WSS can be controlled to carry out noise loading on an original channel of a branch port (TRIB) affected by fault light. Accordingly, the target egress WSS may noise load the original channel of the tributary port (TRIB) that is affected by the fault light thereon.

Alternatively, the network element controller 20 may store the channel configuration information of the optical link in the corresponding target network element in advance. Of course, the network element controller 20 may also query the optical transmission device in the corresponding target network element 10, and obtain the channel configuration information of the optical link in the target network element from the optical transmission device in the target network element 10. The channel configuration information may include a communication frequency band of a channel transmitted in the optical link, and the like. Further, the network element controller 20 may obtain, from the channel configuration information of the optical link in the target network element, the channel configuration information of the original channel of the tributary port (TRIB) of the target egress WSS, which is affected by the failed optical link.

Further, the target outlet WSS may switch the target frequency spectrum having the same frequency band as the original channel of the branch port (TRIB) affected by the optical failure link in the noise signal to the common port (COMM) of the target outlet WSS, thereby implementing noise loading on the original channel.

In the embodiment of the present application, for an egress WSS in an optical transmission network, a spare tributary port (TRIB) may be preloaded with a noise signal. In this embodiment of the present application, for convenience of description and distinction, a branch port on the target egress WSS, which is affected by the failed optical link, may be defined as a first branch port; and defining the branch port loaded with noise on the target outlet WSS as a second branch port. When the optical transmission network normally operates, the outlet WSS may establish an optical transmission medium channel between the branch port loaded with noise and the common port (COMM), and configure a communication frequency band of the optical transmission medium channel to cover a communication frequency band of an idle channel in the optical transmission network, but not include a communication frequency band supported by a channel already used by the optical transmission network. Thus, the outlet WSS can carry out wave band aggregation on the noise in the optical transmission medium channel and the optical signals transmitted by other optical transmission medium channels; and outputting the aggregated optical signal to an optical link connected with other network elements, thereby realizing the noise loading of an idle channel.

Based on this, when the target outlet WSS performs noise loading on the noise loading of the original channel of the first branch port, the first optical transmission medium channel between the first branch port and the common port (COMM) may be deleted; and configuring a second optical transmission medium channel between the second branch port and a common port (COMM) to have the same communication frequency band as the first optical transmission medium channel. In this way, the second optical transmission medium channel can switch the target spectrum having the same frequency band as the original optical channel in the noise signal to the common port (COMM) of the target outlet WSS, thereby implementing noise loading on the original channel of the first branch port.

In this embodiment, the cell controller 20 may control the target egress WSS to perform noise loading on the original channel of the first branch port by an instruction. Specifically, the primitive controller 20 may provide a channel switch instruction to the target egress WSS. The channel switching instruction includes: the identification of the first branch port, the identification of the second branch port and the communication frequency band of the original signal of the first branch port. The target egress WSS may delete the first optical transmission medium channel between the first branch port and the common port (COMM) in response to the instruction; and configuring a second optical transmission medium channel between the second branch port and a common port (COMM) to have the same communication frequency band as the first optical transmission medium channel. In this way, the target spectrum having the same frequency band as the original channel of the first branch port in the noise signal can be switched to the common port (COMM) of the target outlet WSS through the second optical transmission medium channel, so as to implement noise loading on the original channel of the first branch port.

In the embodiment of the application, the network element controller is used as a control unit for loading the channel noise to process the channel noise loading logic of the local network element, so that the localization of the channel noise loading logic is realized. Compared with the scheme that the noise loading is controlled by the centralized management unit, the method has the advantages that information transmission links are reduced, timeliness and speed of channel noise loading are improved, and stability of the optical transmission network is improved.

In the embodiment of the present application, in addition to providing the channel noise loading scheme, a channel noise cleaning scheme is also provided. The following provides an exemplary description of the channel noise removal method provided in the embodiments of the present application.

In the embodiment of the present application, the network element controller may be used as a control unit when channel noise is removed, and may also be autonomously controlled by an optical transmission device in the target network element. Correspondingly, the network element controller 20 corresponding to the target network element or the optical transmission device in the target network element may control the target egress WSS to perform noise removal on the original channel of the first branch port and recover the original channel communication when sensing that the optical transmission network failure is recovered.

In the embodiment of the present application, a specific implementation form of the network element controller 20 corresponding to the target network element or the optical transmission device in the target network element sensing the failure recovery of the optical transmission network is not limited. In some embodiments, after the failure recovery of the optical transmission network, the optical power monitored by the failure monitoring unit is greater than the set power threshold, and a non-optical warning clearing message may be sent. The network element controller 20 corresponding to the target network element may determine that the optical transmission network has failed to recover when monitoring that no warning clearing message is sent. For example, the cell controller 20 corresponding to the target cell may determine that the optical transmission network has failed to recover when the non-optical warning clearing message is received within the set duration. And for the optical transmission equipment in the target network element, the fault recovery of the optical transmission network and the like can be determined under the condition that no optical warning clearing message is monitored.

Further, the network element controller 20 corresponding to the target network element or the optical transmission device in the target network element may control the target outlet WSS to perform noise removal on the original channel of the first branch port, and recover the original channel communication. Specifically, the target outlet WSS may delete the configuration of the communication frequency band of the original channel of the first branch port in the second optical transmission medium channel between the second branch port and the common port (COMM), so that the second optical transmission medium channel no longer loads the target frequency spectrum having the same frequency band as the original channel of the first branch port. Further, the target egress WSS may reestablish the first optical transmission medium channel between the first branch port and the common port (COMM); and configuring the communication frequency band of the reestablished first optical transmission medium channel as the communication frequency band of the original channel.

In this embodiment of the present application, when an optical transmission network fails, after noise loading is performed on an original channel of a first branch port, a network element controller 20 corresponding to a target network element or an optical transmission device in the target network element may set the first branch port as an associated port of a second branch port; and storing the association relationship between the second branch port and the first branch port. And the target outlet WSS can carry out noise elimination on the original channel of the first branch port based on the incidence relation under the condition of fault recovery of the optical transmission network, and recover the original channel communication.

Specifically, when the communication frequency band of the reestablished first optical transmission medium channel is configured as the communication frequency band of the original optical channel, the target outlet WSS may query the association relationship between the second branch port and the first branch port to determine the first branch port associated with the second branch port; acquiring the communication frequency band of the original channel of the first branch port from the incidence relation; further, the communication band of the reestablished first optical transmission medium channel may be configured as the communication band of the original channel.

For the optical transmission network provided by the embodiment of the application, besides the network element controller as the control unit for channel loading, the centralized management unit can also be used as the control unit for channel loading. As shown in fig. 7, a centralized management unit 30 is provided. A centralized management unit 30 is communicatively connected to each network element 10. As for the communication connection between the centralized management unit 30 and the network element 10, reference may be made to the communication between the network element controller 20 and the network element 10, which is not described herein again.

In the embodiment shown in fig. 7, the channel noise loading of a plurality of network elements 10 may be centrally controlled by a centralized management unit 30. In case of a failure of the optical transmission network, the failure monitoring unit may send a no light warning to the central management unit. Accordingly, the central management unit determines that the optical transmission network is malfunctioning in case of receiving no light warning. Further, the centralized management unit 30 may acquire the identifier of the monitored unit included in the non-light warning from the non-light warning; and determining a fault optical link according to the identification of the monitored unit and the pre-stored topological structure information of the optical transmission network. For a specific implementation of the centralized management unit 30 determining the failed optical link, reference may be made to the related contents of the network element controller 20 determining the failed optical link in the above embodiments, and details are not described herein again.

Further, the centralized management unit 30 may determine the target egress WSS affected by the failed optical link and the first branch port of the target egress WSS. For a specific implementation of the process, reference may be made to the above-mentioned contents of determining, by the network element controller, the target egress WSS and the first branch port of the target egress WSS, which are not described herein again.

Further, the centralized management unit 30 may control the target egress WSS to perform noise loading on the original channel of the first branch port. For a specific implementation manner that the target egress WSS performs noise loading on the original channel of the first branch port, reference may be made to relevant contents of the foregoing embodiments, and details are not described herein again.

Of course, when the optical transmission network is recovered from a failure, the centralized management unit 30 may also control the target egress WSS to perform noise removal on the original channel of the first branch port, and for a specific embodiment, reference may be made to the related content of performing noise removal on the original channel of the first branch port by the network element controller, which is not described herein again.

For the scheme of loading and clearing channel noise by the centralized management unit, it needs to rely on multi-flow interaction between the centralized management unit and each network element and end-to-end confirmation of the channel, and compared with the scheme of loading and clearing channel noise locally by the network element, the timeliness is poor, and the stability of the optical transmission network is affected to a certain extent. Especially, during multi-flow interaction, before channel noise is loaded, a fault channel of the optical transmission network is in a no-signal state, and the number of used channels in the optical transmission network is reduced in the period of time, so that the stability of the optical transmission network is influenced.

On the other hand, the scheme of channel noise loading and cleaning by the centralized management unit needs to rely on the robustness and reliability of the centralized management network and the centralized management unit. Once the centralized management network and the centralized management unit have faults or abnormalities, the centralized management unit cannot load and clear noise on the optical transmission network, and normal operation of the optical transmission network is affected. Especially, after the failure recovery of the optical transmission network, if the centralized management network and the centralized management unit have a failure or abnormality, the noise in the original channel cannot be removed, the normal communication of the original channel cannot be recovered, and the normal optical signal transmission of the optical transmission network is affected.

Based on the above analysis, the scheme for loading and clearing channel noise for the local network element by the network element controller provided in the above embodiment can reduce the interaction flow, and is helpful for improving the timeliness of loading and clearing channel noise. On the other hand, the scheme of loading and clearing the channel noise to the local network element by the network element controller does not depend on the robustness and reliability of a centralized management network, and is beneficial to improving the robustness of loading and clearing the channel noise.

For the above scheme of implementing channel noise removal by the optical transmission device in the network element, sinking the channel noise removal logic to the local optical transmission device can further reduce the interaction flow, and is helpful to further improve the timeliness of channel noise removal. On the other hand, the scheme of channel noise removal by the optical transmission equipment does not rely on the robustness and reliability of a centralized management network, even does not rely on communication between the network element controller and the network elements, and is beneficial to further improving the robustness of channel noise removal.

In addition to the optical transmission network provided in the above embodiments, the embodiments of the present application also provide a channel noise loading and clearing method. The channel noise loading and cleaning method is exemplified below.

Fig. 8 is a flowchart illustrating a channel noise loading method according to an embodiment of the present application. As shown in fig. 9, the channel noise loading method includes:

801. in case a failure of the optical transport network is sensed, a failed optical link in the optical transport network is determined.

802. And determining a target channel influenced by the fault optical link from a target network element corresponding to the network element controller.

803. And controlling the target network element to carry out noise loading on the target channel.

In an embodiment of the present application, an optical transmission network includes a plurality of network elements; and the optical connections among the network elements. Each network element can be correspondingly provided with a network element controller. Each network element corresponds to one or more network element controllers respectively; and is in communication connection with the corresponding network element controller. Each network element has an independent corresponding network element controller. For the structures of the optical transmission network, the network element, and the network element controller, reference may be made to the relevant contents of the above system embodiments, and details are not described herein again.

In this embodiment, the cell controller may sense a state of the optical transmission network, and in a case where a failure of the optical transmission network is sensed, in step 801, determine a failed optical link in the optical transmission network; in step 802, determining a target channel affected by the failed optical link from a target network element corresponding to the network element controller; then, in step 803, the target network element may be controlled to perform noise loading control on the target channel, so that the frequency spectrum of the noise signal loaded by the target channel has the same frequency range as the communication frequency band of the channel, thereby implementing channel noise loading of the local network element by the network element controller.

In the embodiment of the present application, a specific implementation form of the network element is not limited. The channel noise loading method provided in the embodiment of the present application is specifically described below with reference to a specific network element structure.

In some embodiments, each network element comprises: ROADM. In this embodiment, multiple network elements may be optically linked through a ROADM. For the specific structure of the ROADM, reference may be made to the relevant contents of the above system embodiments, and details are not described here.

In the embodiment of the present application, a specific implementation form of sensing the state of the light transmission network by the network element controller is not limited. In some embodiments, a fault monitoring unit is disposed on an optical link of an optical transmission network. The implementation of the light source failure monitor can refer to the related content of the above system embodiments, and is not described herein again.

The fault monitoring unit is used for monitoring the power of the optical link; and under the condition that the detected light power is less than or equal to the set power threshold, providing a non-light warning (LOS) to the network element controller corresponding to the target network element monitored by the fault monitoring unit. Correspondingly, the network element controller corresponding to the target network element determines that the optical transmission network fault is sensed under the condition that no light warning is received.

Further, a failed optical link may be determined. In some embodiments, the non-light warning includes an identification of the monitored unit. For the description of the identifier of the monitored unit, reference may be made to the related contents of the above embodiment of the optical transmission network, and details are not described herein again.

The network element controller stores topology information of the optical transmission network in advance. Based on the topological structure information of the optical transmission network, the network element controller can acquire the identifier of the monitored unit from the lightless warning when determining the fault optical link; and determining a fault optical link according to the identification of the monitored unit and the pre-stored topological structure information of the optical transmission network.

Optionally, the identification of the monitored unit may be used to match in topology information of the optical transmission network to determine a faulty optical link.

In some embodiments, as shown in FIG. 4, a WSS (WSS-I) may be at the ingress of a network element_i) Deploying a fault monitoring unit at a common port (COMM); the fault monitoring unit is used for monitoring an inlet WSS (WSS-I)_i) Of the input optical power of (1). For this fault monitoring unit, the fault monitoring unit may trigger a no light alarm when an optical link between the common port (COMM) of the ingress WSS and other network elements fails. Based on this, under the condition that the identifier of the monitored unit contained in the no-light warning contains the optical link connected with the common port (COMM) of the inlet WSS of the target network element, the network element controller can determine the upstream network element connected with the inlet WSS of the target network element according to the topological structure information of the optical transmission network; and determining an optical link connected between the upstream network element and the target network element as a fault optical link.

At another placeIn some embodiments, as shown in FIG. 5, WSS (WSS-E) may be provided at the egress of the network element_i) Deploying a fault monitoring unit at a tributary port (TRIB); the fault monitoring unit is used for monitoring an export WSS (WSS-E)_i) The branch port (TRIB). Accordingly, upon failure of the optical link connected between the egress WSS and the ingress WSS within the same network element, or upon failure of the optical link between this network element and its upstream network element, the failure monitoring unit at the tributary port (TRIB) of the egress WSS triggers a no-light warning.

Because both the optical link fault in the network element and the optical link fault between the network elements can trigger the fault monitoring unit at the branch port (TRIB) of the exit WSS to send out lightless warning, the network element controller can carry out the fault check in the network element on the target network element under the condition that the identification of the monitored unit contained in the lightless warning contains the branch port (TRIB) of the exit WSS; and determining an optical link in the target network element connected with a branch port (TRIB) of the outlet WSS monitored by the target fault monitoring unit according to the topological structure information of the optical transmission network under the condition that the verification result is that the optical link in the target network element has a fault; and determining the optical link in the target network element as a failed optical link.

For a specific implementation of performing intra-network element fault checking on a target network element, reference may be made to relevant contents of the above system embodiment, which is not described herein again.

Further, the optical link connected to the branch port (TRIB) monitored by the fault monitoring unit may be determined to be a faulty optical link according to the topology information of the optical transmission network.

In still other embodiments, as shown in fig. 6, a fault monitoring unit may be deployed at an add port of an add/drop unit of a network element, where the fault monitoring unit is used for input optical power of the add port. Accordingly, upon failure of the upstream optical link, the failure monitoring unit at the upstream port (TRIB) of the upstream and downstream units triggers a no light alarm.

Based on this, under the condition that the deployment position of the target fault monitoring unit providing no light warning is determined to comprise the uplink port of the uplink and downlink unit, the uplink optical link connected with the uplink port can be determined according to the topological structure relationship of the optical transmission network; and determining the up optical link connected with the port as a fault optical link.

For an optical transport network, an optical link failure does not affect the operation of the upstream optical transport equipment and the upstream optical link of the failed optical link, but may affect the optical transport of the downstream optical transport equipment and the downstream optical link. In each network element of the optical transmission network, the egress WSS is configured to transmit the optical signal to a downstream network element. In order to prevent the fault from being conducted downstream, after the fault optical link is determined, a target outlet WSS influenced by the fault optical link and a branch port of the target outlet WSS influenced by the fault optical link can be determined from the target network element; further, the original channel of the branch port of the target outlet WSS affected by the failed optical link may be determined as the target channel.

Optionally, a downstream egress WSS of the failed optical link may be determined according to the topology information of the optical transmission network; and determining the downstream outlet WSS as the target outlet WSS. Further, a branch port connected to the failed optical link on the target egress WSS may be determined as the branch port of the target egress WSS affected by the failed optical link.

And as the branch port on the target outlet WSS, which is affected by the optical link, has no optical signal input, the optical link fault can be conducted downstream. In the embodiment of the application, in order to improve the system stability, after determining the target outlet WSS affected by the failed optical link and the branch port of the affected target outlet WSS; and the WSS can control the target outlet to carry out noise loading on the original channel of the branch port influenced by the fault light. Accordingly, the target egress WSS may noise load the original channel of the tributary port affected by the fault light thereon.

Optionally, channel configuration information of the optical link in the corresponding target network element may be stored in advance. The channel configuration information may include a communication frequency band of a channel transmitted in the optical link, and the like. Further, the channel configuration information of the original channel of the branch port of the target outlet WSS influenced by the fault optical link can be obtained from the prestored channel configuration information of the optical link in the target network element; and providing the channel configuration information of the original channel to the target outlet WSS so as to control the target outlet WSS to switch the channel configuration information of the original channel of the branch port affected by the optical fault link in the noise signal to a common port of the target outlet WSS, thereby realizing noise loading on the original channel.

Correspondingly, the target outlet WSS can switch the target frequency spectrum having the same frequency band as the original channel of the branch port affected by the optical failure link in the noise signal to the common port of the target outlet WSS, thereby implementing noise loading on the original channel.

In the embodiment of the present application, for an egress WSS in an optical transmission network, an idle tributary port may be preloaded with a noise signal. In this embodiment of the present application, for convenience of description and distinction, a branch port on the target egress WSS, which is affected by the failed optical link, may be defined as a first branch port; and defining the branch port loaded with noise on the target outlet WSS as a second branch port. When the optical transmission network normally operates, the outlet WSS may establish an optical transmission medium channel between the branch port loaded with noise and the common port, and configure a communication frequency band of the optical transmission medium channel to cover a communication frequency band of an idle channel in the optical transmission network, but not include a communication frequency band supported by a channel already used by the optical transmission network. Thus, the outlet WSS can carry out wave band aggregation on the noise in the optical transmission medium channel and the optical signals transmitted by other optical transmission medium channels; and outputting the aggregated optical signal to an optical link connected with other network elements, thereby realizing the noise loading of an idle channel.

Based on this, when the target outlet WSS performs noise loading on the noise loading of the original channel of the first branch port, the first optical transmission medium channel between the first branch port and the common port may be deleted; and a second optical transmission medium channel between the second branch port and the common port is configured to have the same communication frequency band as the first optical transmission medium channel. Therefore, the target frequency spectrum with the same frequency band as the original optical channel in the noise signal can be switched to the common port of the target outlet WSS through the second optical transmission medium channel, and the noise loading of the original channel of the first branch port is realized.

In the embodiment of the application, the target outlet WSS may be controlled by an instruction to perform noise loading on the original channel of the first branch port. Specifically, the network element controller may provide a channel switching instruction to the target egress WSS. The channel switching instruction includes: the identification of the first branch port, the identification of the second branch port and the communication frequency band of the original signal of the first branch port. The target outlet WSS can respond to the instruction and delete the first optical transmission medium channel between the first branch port and the common port; and a second optical transmission medium channel between the second branch port and the common port is configured to have the same communication frequency band as the first optical transmission medium channel. Therefore, the target frequency spectrum which has the same frequency band as the original channel of the first branch port in the noise signal can be switched to the common port of the target outlet WSS through the second optical transmission medium channel, and the noise loading of the original channel of the first branch port is realized.

In the embodiment of the application, besides providing a channel noise loading scheme, a channel noise cleaning method is also provided. The following provides an exemplary description of the channel noise removal method provided in the embodiments of the present application.

Fig. 9 is a flowchart illustrating a channel noise removing method according to an embodiment of the present application. As shown in fig. 9, the channel noise removing method includes:

901. and recording a target channel loaded by noise in a target network element when the optical transmission network fails.

902. And controlling the target network element to carry out noise removal on the target channel under the condition of sensing the fault recovery of the optical transmission network.

In the embodiment of the present application, the network element controller may be used as a control unit when channel noise is removed, and may also be autonomously controlled by an optical transmission device in the target network element. Correspondingly, under the condition that the network element controller corresponding to the target network element or the optical transmission equipment in the target network element senses that the optical transmission network is recovered from a fault, the target network element can be controlled to carry out noise removal on the target channel loaded with noise in the target network element, and the target channel communication is recovered.

Specifically, the target outlet WSS may be controlled to perform noise cleaning on the original channel of the first branch port, and recover the original channel communication.

In the embodiment of the present application, a specific implementation form of sensing a failure recovery of a light transmission network by a network element controller corresponding to a target network element or a light transmission device in the target network element is not limited. In some embodiments, after the failure recovery of the optical transmission network, the optical power monitored by the failure monitoring unit is greater than the set power threshold, and a non-optical warning clearing message is sent out. And determining the fault recovery of the optical transmission network by the network element controller corresponding to the target network element under the condition of monitoring no light warning clearing message. For example, the network element controller corresponding to the target network element may determine that the optical transmission network has failed to recover when the non-optical warning removal message is continuously received within a set duration. And for the optical transmission equipment in the target network element, the fault recovery of the optical transmission network and the like can be determined under the condition that no optical warning clearing message is monitored.

Further, a network element controller corresponding to the target network element or an optical transmission device in the target network element may control the target outlet WSS to perform noise removal on the original channel of the first branch port, and recover the original channel communication. Specifically, the target outlet WSS may delete the configuration of the communication frequency band of the original channel of the first branch port in the second optical transmission medium channel between the second branch port and the common port, so that the second optical transmission medium channel no longer loads the target frequency spectrum having the same frequency band as the original channel of the first branch port. Further, the target outlet WSS may reestablish the first optical transmission medium channel between the first branch port and the common port; and configuring the communication frequency band of the reestablished first optical transmission medium channel as the communication frequency band of the original channel.

In this embodiment of the present application, when an optical transmission network fails, after an original channel of a first branch port is subjected to noise loading, a network element controller corresponding to a target network element or an optical transmission device in the target network element may set the first branch port as an associated port of a second branch port; and storing the association relationship between the second branch port and the first branch port. And the target outlet WSS can carry out noise elimination on the original channel of the first branch port based on the incidence relation under the condition of fault recovery of the optical transmission network, and recover the original channel communication.

In this embodiment, sinking the channel noise removal logic to the local optical transmission device can further reduce the interaction flow, which is helpful to further improve the timeliness of channel noise removal. On the other hand, the scheme of channel noise removal by the optical transmission equipment does not rely on the robustness and reliability of a centralized management network, even does not rely on communication between the network element controller and the network elements, and is beneficial to further improving the robustness of channel noise removal.

The following takes three fault scenarios, such as an inter-network-element optical link fault, an intra-network-element optical link fault, and an uplink optical link fault, as examples, and an exemplary description is given to the channel noise loading and channel noise removing method provided in the embodiment of the present application.

Application scenario 1: inter-network element fault

Fig. 10 is a flowchart illustrating a noise loading method when an optical link between network elements fails according to an embodiment of the present application. As shown in fig. 10, the noise loading method may include:

and S11, optical link failure between network elements.

And S12, triggering the downstream optical amplifier of the fault optical link to automatically close.

S13, the fault monitoring unit of the downstream network element of the faulty optical link sends out a non-optical warning.

And S14, determining the fault of the optical transmission network when the network element controller corresponding to the downstream network element of the fault optical link receives the lightless warning.

S15, according to the topology structure information of the optical transmission network without light warning, determining the target exit WSS influenced by the optical fault link and the first branch port influenced by the optical fault link from the downstream network element of the optical fault link.

And S16, deleting the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

S17, configuring that the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target outlet WSS has the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band having the same frequency band range as the original channel of the first branch port to the common port of the target outlet WSS through the second optical transmission medium channel.

And S18, setting the first branch port as the associated port of the second branch port.

Accordingly, as shown in fig. 11, the method for clearing noise when recovering from an optical link failure between network elements may include:

and S21, recovering the optical link between the network elements.

And S22, triggering the downstream optical amplifier of the fault optical link to automatically start.

S23, a fault monitoring unit of a downstream network element of the fault optical link has no light warning clearing message; and the network element controller corresponding to the downstream network element of the fault optical link receives the lightless warning clearing message and determines that the optical transmission network is recovered.

And S24, judging whether the associated ports of the second branch circuit port comprise the first branch circuit port. If yes, go to step S25; if the judgment result is negative, the noise clearing operation is finished when the optical link between the network elements is recovered.

And S25, deleting the frequency band configuration of the original channel of the second optical transmission medium channel relative to the first branch port.

And S26, reestablishing the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

And S27, configuring the communication frequency band of the first optical transmission medium channel as the communication frequency band of the original channel of the first branch port.

Application scenario 2: optical link failure in network elements

Fig. 12 is a flowchart illustrating a method for loading noise when an optical link in a network element fails according to an embodiment of the present application. As shown in fig. 12, the noise loading method may include:

and S31, the optical link in the network element fails.

S32, the failure monitoring unit at the first tributary port of the downstream egress WSS of the failed optical link issues a lightless warning.

And S33, the network element controller corresponding to the network element receives the lightless warning and determines the fault of the optical transmission network.

And S34, checking whether the optical transmission fault is the optical link fault in the network element. If the check result is yes, step S35 is executed, and if the determination result is no, the noise loading operation when the optical link failure in the network element is recovered is ended.

And S35, deleting the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

S36, configuring that the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target outlet WSS has the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band having the same frequency band range as the original channel of the first branch port to the common port of the target outlet WSS through the second optical transmission medium channel.

And S37, setting the first branch port as the associated port of the second branch port.

Accordingly, as shown in fig. 13, the method for clearing noise when recovering from an optical link failure in a network element may include:

and S41, recovering the optical link in the network element.

S42, a fault monitoring unit at a first branch port of a downstream outlet WSS of the fault optical link sends out a lightless warning clearing message; and the network element controller corresponding to the network element receives the lightless warning clearing message and determines that the optical transmission network is recovered.

And S43, judging whether the associated ports of the second branch circuit port comprise the first branch circuit port. If yes, go to step S44; if the judgment result is negative, the noise clearing operation is finished when the optical link between the network elements is recovered.

And S44, deleting the frequency band configuration of the original channel of the second optical transmission medium channel relative to the first branch port.

And S45, reestablishing the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

And S46, configuring the communication frequency band of the first optical transmission medium channel as the communication frequency band of the original channel of the first branch port.

Application scenario 3: upstream optical link failure

Fig. 14 is a schematic flowchart of a noise loading method in the case of an uplink optical link failure according to an embodiment of the present application. As shown in fig. 14, the noise loading method may include:

and S51, failure of the uplink optical link.

S52, the fault monitoring unit at the upstream port of the upstream and downstream units in the downstream network element of the upstream optical link sends out no light alarm.

And S53, the network element controller corresponding to the downstream network element of the uplink optical link receives the lightless warning, and determines the fault of the optical transmission network.

And S54, determining a target exit WSS influenced by the optical fault link and a first branch port influenced by the optical fault link from the downstream network element of the optical link according to the lightless warning and the topological structure information of the optical transmission network.

And S55, deleting the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

S56, configuring that the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target outlet WSS has the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band having the same frequency band range as the original channel of the first branch port to the common port of the target outlet WSS through the second optical transmission medium channel.

And S57, setting the first branch port as the associated port of the second branch port.

Accordingly, as shown in fig. 15, for an embodiment in which an optical power detector is disposed at an add port of an add/drop unit, the method for clearing noise when an add optical link failure is recovered may include:

and S61, recovering the uplink optical link.

S62, a fault monitoring unit at an upper port of an upper path unit and a lower path unit in a downstream network element of the upper path optical link sends out a lightless warning clearing message; and the network element controller corresponding to the downstream network element of the uplink optical link receives the lightless warning clearing message.

S63, judging whether the fault monitoring units of the upper and lower road units send out lightless warning; if the determination result is negative, go to step S64; if the judgment result is yes, the noise clearing operation is finished when the optical link between the network elements is recovered.

And S64, judging whether the associated ports of the second branch circuit port comprise the first branch circuit port. If yes, go to step S65; if the judgment result is negative, the noise clearing operation is finished when the optical link between the network elements is recovered.

And S65, deleting the frequency band configuration of the original channel of the second optical transmission medium channel relative to the first branch port.

And S66, reestablishing the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

And S67, configuring the communication frequency band of the first optical transmission medium channel as the communication frequency band of the original channel of the first branch port.

Accordingly, as shown in fig. 16, for an embodiment in which an add port of an add/drop unit is provided with an optical channel detector, the method for clearing noise when an add optical link fails to recover may include:

and S71, recovering the uplink optical link.

S72, carrying out periodic spectrum scanning by the optical channel detector at the upper port of the upper and lower path units; in the case where optical power recovery is scanned, the upstream optical link recovery is determined.

And S73, judging whether the associated ports of the second branch circuit port comprise the first branch circuit port. If yes, go to step S74; if the judgment result is negative, the noise clearing operation is finished when the optical link between the network elements is recovered.

And S74, deleting the frequency band configuration of the original channel of the second optical transmission medium channel relative to the first branch port.

And S75, reestablishing the first optical transmission medium channel between the first branch port and the common port of the target outlet WSS.

And S76, configuring the communication frequency band of the first optical transmission medium channel as the communication frequency band of the original channel of the first branch port.

It should be noted that the execution subjects of the steps of the methods provided in the above embodiments may be the same device, or different devices may be used as the execution subjects of the methods. For example, the execution subject of

steps

801 and 802 may be device a; for another example, the execution subject of step 801 may be device a, and the execution subject of step 802 may be device B; and so on.

In addition, in some of the flows described in the above embodiments and the drawings, a plurality of operations are included in a specific order, but it should be clearly understood that the operations may be executed out of the order presented herein or in parallel, and the sequence numbers of the operations, such as 801, 802, etc., are merely used for distinguishing different operations, and the sequence numbers themselves do not represent any execution order. Additionally, the flows may include more or fewer operations, and the operations may be performed sequentially or in parallel.

Accordingly, embodiments of the present application also provide a computer-readable storage medium storing computer instructions, which, when executed by one or more processors, cause the one or more processors to perform the steps of the above-described noise loading and/or noise cleaning method.

It should be noted that, the descriptions of "first", "second", etc. in this document are used for distinguishing different messages, devices, modules, etc., and do not represent a sequential order, nor limit the types of "first" and "second" to be different.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

The storage medium of the computer is a readable storage medium, which may also be referred to as a readable medium. Readable storage media, including both permanent and non-permanent, removable and non-removable media, may implement the information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An optical transmission network, comprising: a plurality of network elements and a plurality of network element controllers corresponding to the plurality of network elements respectively; the network element controllers are in communication connection with the corresponding network elements; said plurality of network elements are optically connected;

2. The network of claim 1, wherein each network element comprises: reconfigurable optical add-drop multiplexer ROADM; the plurality of network elements are optically connected through the ROADM;

the ROADM includes: at least one external wavelength selective switch WSS module; the external WSS module comprises: an inlet WSS and an outlet WSS; the external WSS module is optically connected with external WSS modules in other ROADMs through the inlet WSS and the outlet WSS;

when determining the target channel affected by the faulty optical link, the cell controller is specifically configured to:

determining a target exit WSS influenced by the fault optical link and a first branch port of the target exit WSS from the target network element; and determining the original channel of the first branch port as the target channel.

3. The network of claim 2, wherein when the target network element performs noise loading on the target channel of the first branch port, the target network element is specifically configured to:

and the target outlet WSS switches a target frequency spectrum which has the same frequency band with the original channel in a noise signal to a common port of the target outlet WSS so as to carry out noise loading on the target channel.

4. The network of claim 2 or 3, wherein the ROADM is deployed in an optical transmission device; the optical transmission device or the network element controller is configured to:

and controlling the target outlet WSS to carry out noise removal on the original channel under the condition of sensing the fault recovery of the optical transmission network.

5. A noise loading method is suitable for a network element controller and is characterized by comprising the following steps:

6. The method according to claim 5, wherein when determining the target channel affected by the faulty optical link from the target network element corresponding to the network element controller, specifically:

determining a target exit WSS influenced by the fault optical link and a first branch port of the target exit WSS from the target network element;

and determining the original channel of the first branch port as the target channel.

7. The method of claim 6, wherein the controlling target network element noise-loading the target channel comprises:

and controlling the target outlet WSS to switch a target frequency spectrum which has the same frequency band as the original channel in a noise signal to a common port of the target outlet WSS so as to control the target network element to carry out noise loading on the target channel.

8. The method of claim 5, further comprising:

receiving a lightless warning provided by a fault monitoring unit of the optical transmission network;

determining that the optical transport network fault is sensed in the event that the no light warning is received.

9. The method of claim 8, wherein determining the failed optical link comprises:

obtaining the identification of the monitored unit contained in the non-luminous warning from the non-luminous warning;

and determining the fault optical link according to the identification of the monitored unit and the pre-stored topological structure information of the optical transmission network.

10. The method of claim 9, wherein the determining, from the target network element, a target egress WSS affected by the failed optical link and a first branch port of the target egress WSS comprises:

determining a downstream exit WSS of the fault optical link according to the topological structure information;

determining the downstream outlet WSS as the target outlet WSS; and determining a branch port connected with the fault optical link on the target outlet WSS as the first branch port.

11. The method according to any one of claims 6-10, further comprising:

and controlling the target network element to carry out noise removal on the target channel under the condition that the fault recovery of the optical transmission network is sensed.

12. The method of claim 11, wherein the controlling the target network element to perform noise cleaning on the target channel comprises:

controlling the target outlet WSS to delete the communication frequency band configuration of the target channel in a second optical transmission medium channel; the second optical transmission medium channel is an optical transmission medium channel between a second branch port of the target outlet WSS loaded with the noise signal and a common port of the target outlet WSS;

reestablishing a first optical transmission medium channel between the first branch port and the common port of the target outlet WSS;

and configuring the communication frequency band of the reestablished first optical transmission medium channel as the communication frequency band of the original channel.

13. The method of claim 12, further comprising:

after noise loading is carried out on an original channel of the first branch port, setting the first branch port as an associated port of the second branch port; storing the incidence relation between the second branch port and the first branch port;

the target outlet WSS, when configuring the communication frequency band of the reestablished first optical transmission medium channel as the original communication frequency band, is specifically configured to:

querying the association relationship to determine a first branch port associated with the second branch port;

acquiring the communication frequency band of the original channel from the incidence relation;

14. A method of noise cancellation, comprising: