Optical transmission networks, noise loading and noise cancellation methods

Abstract

This application provides an optical transmission network, a noise loading method, and a noise cancellation method. In this application embodiment, a network element controller acts as the control unit for channel noise loading, handling the channel noise loading of local network elements. Compared to a centralized management unit acting as the control unit for channel noise, this reduces the signal flow transmission process, helps improve the timeliness of channel loading, and thus helps improve system stability.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical transmission network, noise loading, and noise cancellation method. Background Technology

[0002] Optical transmission networks can employ wavelength combination techniques known as wavelength division multiplexing (WDM) or dense wavelength division multiplexing (DWDM) to multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplex multiplexed onto a single optical fiber. For WDM or DWDM optical transmission networks, noise filling techniques are used to load noise onto idle or unused channels, resulting in relatively stable system performance. However, during optical transmission network failures, the rate at which noise is loaded onto the faulty channels significantly impacts network stability. Therefore, improving the channel noise loading in optical transmission networks remains a key research challenge in this field. Summary of the Invention

[0003] This application provides an optical transmission network, a noise loading method, and a noise cancellation method to improve the channel noise loading speed and enhance the stability of the optical transmission network.

[0004] This application provides an optical transmission network, including: multiple network elements and multiple network element controllers corresponding to the multiple network elements; the multiple network element controllers are communicatively connected to their respective network elements; the multiple network elements are optically connected.

[0005] The network element controller is configured to: determine the faulty optical link when a fault is detected in the optical transmission network; determine the target channel affected by the faulty optical link from the target network elements corresponding to the network element controller; and control the target network elements to apply noise to the target channel.

[0006] This application also provides a noise loading method, applicable to network element controllers, including:

[0007] In the event of a detected optical transmission network fault, the faulty optical link in the optical transmission network is identified;

[0008] From the target network elements corresponding to the network element controller, determine the target channel affected by the faulty optical link;

[0009] The target network element is controlled to load noise onto the target channel.

[0010] This application also provides a noise reduction method, including:

[0011] Record the target channel with noise loading in the target network element when the optical transmission network fails;

[0012] Upon sensing that the optical transmission network has recovered from a fault, the target network element is controlled to perform noise removal on the target channel.

[0013] In this embodiment, the network element controller acts as the control unit for channel noise loading, which handles the channel noise loading of local network elements. Compared with the centralized management unit acting as the control unit for channel noise, this reduces the signal flow transmission process, helps improve the timeliness of channel loading, and thus helps improve system stability. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0015] Figure 1 and Figure 2 This is a schematic diagram of the structure of an optical transmission network provided in an embodiment of this application;

[0016] Figure 3 This is a schematic diagram of the structure of ROADM provided in the embodiments of this application;

[0017] Figure 4 This is a schematic diagram of the channel noise loading process when an inter-network element optical link failure occurs in an optical transmission network provided in an embodiment of this application;

[0018] Figure 5 This application provides a schematic diagram of the channel noise loading process when an optical link failure occurs within a network element in an optical transmission network.

[0019] Figure 6 This application provides a schematic diagram of the channel noise loading process when an uplink optical link failure occurs in an optical transmission network.

[0020] Figure 7 This is a schematic diagram of another optical transmission network provided in an embodiment of this application;

[0021] Figure 8 A flowchart illustrating the noise loading method provided in an embodiment of this application;

[0022] Figure 9 A flowchart illustrating the noise reduction method provided in an embodiment of this application;

[0023] Figure 10 A flowchart illustrating the noise loading method for inter-network optical link failure provided in the application embodiment;

[0024] Figure 11 A flowchart illustrating the noise cancellation method for inter-network optical link failure provided in this application embodiment;

[0025] Figure 12A flowchart illustrating the noise loading method for optical link failure within a network element provided in the application embodiment;

[0026] Figure 13 A flowchart illustrating the noise cancellation method for optical link failure within a network element provided in this application embodiment;

[0027] Figure 14 A flowchart illustrating the noise loading method for inter-network optical link failure provided in this application embodiment;

[0028] Figure 15 and Figure 16 This is a flowchart illustrating a noise cancellation method for inter-network optical link failures provided in an embodiment of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] For WDM or DWDM optical transmission networks, noise filling techniques are used to load noise onto idle or unused channels, resulting in relatively stable system performance. However, during network failures, the rate at which noise is loaded onto the faulty channels significantly impacts network stability. Therefore, improving channel noise loading in optical transmission networks remains a key research challenge in this field.

[0031] In some embodiments of this application, the network element controller acts as the control unit for channel noise loading, which handles the channel noise loading of local network elements. Compared with the centralized management unit acting as the control unit for channel noise, this reduces the signal flow transmission process, helps improve the timeliness of channel loading, and thus helps improve system stability.

[0032] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0033] It should be noted that the same reference numerals denote the same object in the following figures and embodiments. Therefore, once an object is defined in one figure or embodiment, it does not need to be discussed further in subsequent figures and embodiments.

[0034] Figure 1 This is a schematic diagram of the structure of an optical transmission network provided in an embodiment of this application. Figure 1As shown, an optical transmission network may include multiple network elements 10. Multiple means two or more. Figure 1 The illustration only shows three network elements 10, but this is not intended to be limiting. Multiple network elements 10 are optically connected. In this embodiment, the optical connection can be made through any optical link, such as through optical fiber, optical waveguide, or spatial optical coupling, but is not limited to these.

[0035] In this embodiment of the application, an optical amplifier (such as an optical amplifier) ​​may also be provided on the optical link. Figure 1 The optical amplifier (shown as a triangle) and dispersion compensation devices (not shown in the attached diagram) are examples of such devices. When the optical link is normal, the optical amplifier amplifies the optical signal in the optical link by converting the energy of the pump light into the energy of the signal light, based on stimulated emission of the laser. In the event of an optical link failure, the downstream optical amplifier of the failed optical link can automatically shut down the pump light, thus automatically shutting down the optical amplifier.

[0036] In the embodiments of this application, the optical amplifier may be an erbium-doped optical fiber amplifier (EDFA) or a semiconductor optical amplifier (SOA), but is not limited to these.

[0037] In this embodiment, network element 10 refers to a network unit in an optical transmission network, which may include one or more optical transmission devices. "Multiple" means two or more. In this embodiment, the optical transmission devices in the same network element 10 may be provided by the same manufacturer or by different manufacturers. Preferably, the optical transmission devices in the same network element 10 are provided by different manufacturers. For optical transmission devices in different network elements 10, they may be provided by the same manufacturer or by different manufacturers.

[0038] In practical applications, in order to achieve complementary advantages and disadvantages among different manufacturers, the optical transmission equipment in the network element 10 can be provided by multiple manufacturers. This can decouple the optical transmission network from the manufacturers, break down the software and hardware technical barriers of optical transmission equipment manufacturers, and achieve software and hardware decoupling, optoelectronic decoupling, and optical layer dimension decoupling based on standardized transmission function modules and data models. This enables the combination of technical advantages of multiple manufacturers and hybrid networking.

[0039] Because different manufacturers use different control logics and optical transmission equipment management methods, therefore, Figure 1 As shown, a network element controller 20 can be set for each network element 10. Each network element corresponds to one or more network element controllers 20 and is communicatively connected to its corresponding network element controller 20. Each network element 10 has an independent corresponding network element controller 20.

[0040] The network element controller 20 and the corresponding network element 10 can be connected wirelessly or via a wired connection. Optionally, the network element 10 can communicate with the corresponding controller 20 via a mobile network. Accordingly, the mobile network standard can be any one of 2G (GSM), 2.5G (GPRS), 3G (WCDMA, TD-SCDMA, CDMA2000, UTMS), 4G (LTE), 4G+ (LTE+), 5G, WiMax, etc. Optionally, the network element 10 can also communicate with its corresponding network element controller 20 via Bluetooth, WiFi, infrared, etc.

[0041] The network element controller 20, also known as the network element management unit, is used to manage and control optical transmission equipment within a local network element. In this embodiment, the implementation of the network element controller 20 is not limited. Optionally, the network element controller 20 can be any device or apparatus with communication and control processing functions, such as a single server device, a cloud-based server array, or a virtual machine (VM) running in a cloud-based server array; alternatively, it can refer to other computing devices with corresponding service capabilities, such as computers or other terminal devices (running service programs).

[0042] In this embodiment, the optical signal bands supported by the optical transmission network are not limited. For example, the optical transmission network may support C-band, L-band, or C+L-band, etc. In practical applications, for optical transmission networks, some bands correspond to channels with optical signals carrying information, indicating that these channels are in use; other bands correspond to channels that are unused or idle.

[0043] Because optical signals of different wavelengths exhibit linear and nonlinear effects during transmission in a channel, these effects significantly impact the stability of optical transmission networks. If no optical signal is transmitted in an unused or idle channel, it may be necessary to use the idle channel and load an optical signal onto it. This can cause transient effects on the optical channel, affecting the stability of other used channels and consequently the stability of the optical transmission network. Therefore, noise filling techniques can be used to load noise signals onto the used channels of idle or unused channels. When the idle channel is needed, an information-carrying optical signal replaces the noise signal, eliminating transient effects and reducing the impact on other channels, thus ensuring relatively stable system performance of the optical transmission network. Channel noise loading refers to the process of loading a noise signal onto the channel.

[0044] Based on the above analysis, in the embodiments of this application, such as Figure 1As shown, idle channels in an optical transmission network can be loaded with noise signals, such as spontaneously radiated noise (ASE). The noise signal transmitted through the idle channel can cover the communication frequency band supported by the idle channel, but not the communication frequency band supported by the channels already used by the optical transmission network. For example, assuming the entire communication frequency band of the optical transmission network is the C+L band, in... Figure 1 In the optical transmission network, the channels already in use are MC1-MC4; correspondingly, the spectrum of noise signals transmitted through the idle channels covers other frequency bands in the C+L band besides the communication frequency bands supported by MC1-MC4.

[0045] During the operation of optical transmission networks, network failures sometimes occur, such as the loss of one or more optical links. To maintain the stability of the optical transmission network, noise loading is required on the channels supported by the failed optical links. The speed of noise loading on the failed channels significantly affects the stability of the network system.

[0046] In this embodiment, to improve the noise loading speed of a faulty channel, channel noise loading in a local network element can be implemented through the network element controller 20. Here, a local network element refers to a network element that is communicatively connected to the network element controller 20. For example, Figure 1 In the diagram, the local network element of network element controller 20, numbered A, is network element 10, numbered NE-A; the local network element of network element controller 20, numbered B, is network element 10, numbered NE-B. The noise loading method provided in this application embodiment will be described below by way of example.

[0047] In this embodiment, the network element controller 20 can sense the state of the optical transmission network and, upon sensing a fault in the optical transmission network, determine the faulty optical link; and from the target network element corresponding to the network element controller 20, determine the target channel affected by the faulty optical link; then, it can control the target network element to perform noise loading control on the target channel, so that the spectrum of the noise signal loaded on the target channel has the same frequency band range as the communication frequency band of the channel, thereby realizing the channel noise loading of the local network element by the network element controller.

[0048] In this application, the specific implementation of the device providing the noise signal is not limited. In some embodiments, the noise signal may be provided by a noise source, or spontaneous emission noise may be generated by the pump source of an optical amplifier, etc.

[0049] In this embodiment, the network element controller acts as the control unit for channel noise loading, which handles the channel noise loading of local network elements. Compared with the centralized management unit acting as the control unit for channel noise, this reduces the signal flow transmission process, helps improve the timeliness of channel loading, and thus helps improve system stability.

[0050] In this application embodiment, the specific implementation form of network element 10 is not limited. The channel noise loading method provided in this application embodiment will be specifically described below with reference to a specific network element structure.

[0051] In some embodiments, such as Figure 2 As shown, each network element 10 includes a reconfigurable optical add-drop multiplexer (ROADM) 101. Each optical transmission device in network element 10 may include ROADM 101. In this embodiment, multiple network elements 10 can be optically linked through ROADM 101. ROADM 101 can perform optical channel add / drop and wavelength-level cross-scheduling between optical channels on a single network element node. Adding an optical channel refers to loading the optical signal onto the optical link, i.e., the optical signal is added from the optical transmitter to the optical transmission network; dropping an optical signal refers to dropping the optical signal from the optical transmission network to the optical receiver, i.e., the optical signal is transmitted from the optical transmission network.

[0052] In this embodiment, as Figure 2 As shown, ROADM 101 includes at least one external wavelength selective switch (WSS) module 101a and an add / drop group (ADG) 101b. The external WSS module 101a and the add / drop group 101b are optically connected. In this embodiment, ADG 101b refers to a module, device, or apparatus that performs add / drop operations on optical signals transmitted in the optical transmission network and adds optical signals to the optical transmission network. The term "external" in the external WSS module 101a can be understood as: sending or receiving optical signals to other ROADMs besides the ROADM to which this WSS module belongs.

[0053] In this embodiment, the add / drop unit 101b is optically connected to the optical transmitter and optical receiver. Specifically, the ADG 101b is connected via an add-on optical link (such as...). Figure 2 The optical links (MC1-MC4 pointing to ADG) are optically connected to the optical transmitter to receive optical signals sent by the optical transmitter; and transmit optical signals to the external WSS module 101a through the optical link between ADG and the external WSS module 101a. ADG 101b also receives optical signals transmitted by the external WSS module 101a and transmits them through a downstream optical link (such as...). Figure 2 The optical links (reverse of ADG in MC1-MC4) will downlink the optical signal to the optical receiver.

[0054] In this embodiment, the external WSS module 101a can be optically connected to external WSS modules in other ROADMs via an optical link. Accordingly, the external WSS module 101a can transmit optical signals to external WSS modules in other ROADMs via the optical link between it and the external WSS modules in other ROADMs.

[0055] In the case where ROADM 101 includes multiple external WSS modules 101a, each external WSS module 101a is optically connected to ADG 101b; and there is an optical connection between every two external WSS modules 101a. Each external WSS module 101a is also optically connected to an external WSS module in another ROADM via an optical link.

[0056] Furthermore, such as Figure 2 As shown, the external WSS module 101a includes: an ingress WSS (denoted as WSS-I). i ) and export WSS (denoted as WSS-E) i Where i = 1, 2, ..., n, and n is a positive integer. Figure 2 The illustration uses n=4 only, but this is not a limitation. For any two external WSS modules in the same ROADM, the tributary port (TRIB) of the input WSS of one external WSS module is optically connected to the tributary port (TRIB) of the output WSS of the other external WSS module. For example, Figure 2 The tributary port 1 of the ingress WSS (WSS-I2) is optically connected to the tributary port 1 of the egress WSS (WSS-E3) of another external WSS module. The common port (COMM) of each ingress WSS is optically connected to the common port (COMM) of the egress WSS in other network elements to receive optical signals transmitted from those other network elements. For example, Figure 2 The common port (COMM) of the ingress WSS in network element 10, designated NE-B, is optically connected to the common ports (COMM) of the egress WSSs in network elements 10, designated NE-A and NE-C, respectively. Correspondingly, the common port (COMM) of each egress WSS is optically connected to the common ports (COMM) of the ingress WSSs of other network elements, for transmitting optical signals to other network elements 10. For example, Figure 2 The common port (COMM) of the outgoing WSS in network element 10, numbered NE-B, is optically connected to the common port (COMM) of the incoming WSS in network element 10, numbered NE-A and NE-C, respectively.

[0057] In this embodiment, the tributary port (TRIB) of the ingress WSS and the tributary port (TRIB) of the egress WSS are optically connected to the uplink / downlink unit 101b. Specifically, the tributary port (TRIB) of the ingress WSS is optically connected to the port corresponding to the downlink optical link of the uplink / downlink unit 101b, for transmitting the optical signal output from the tributary port (TRIB) to the optical receiver via the downlink optical link. For example, Figure 2 In this configuration, the tributary port 3 of the ingress WSS (WSS-I3) is optically connected to the port corresponding to the downstream optical link of ADG 101b, used to transmit the optical signal output from tributary port 3 to the optical receiver via the downstream optical link. The tributary port (TRIB) of the egress WSS is optically connected to the port corresponding to the upstream optical link of the upstream / downstream unit 101b, used to receive the optical signal transmitted via the upstream optical link. For example, in... Figure 2 In the middle, the branch port 3 of the output WSS (WSS-E2) is optically connected to the port corresponding to the uplink optical link of the uplink unit 101b, and is used to receive the optical signal transmitted by the uplink optical link.

[0058] In this application embodiment, the specific implementation of ADG 101b is not limited. In some embodiments, such as Figure 3 The ROADM schematic shown indicates that ADG 101b may include a local WSS module 101c. The local WSS module 101c may include an uplink WSS 101c1 and a downlink WSS 101c2. The common port (COMM) of the uplink WSS 101c1 is optically connected to the uplink optical link and is used to receive optical signals transmitted through the uplink optical link. The common port (COMM) of the downlink WSS 101c2 is optically connected to the downlink optical link and is used to transmit optical signals from the optical transmission network to the downlink optical link.

[0059] Furthermore, for the uplink optical link of the local WSS module 101c, the common port (COMM) of the uplink WSS 101c1 is connected to a optical combiner 101c3, which is used to combine the various optical signals received from the optical receiver and send them to the uplink WSS 101c2. Then, the uplink WSS 101c2 forwards the signal through the optical link to the tributary port (TRIB) of the output WSS of the external WSS module 101a, realizing wavelength division multiplexing of the optical link. Optionally, an optical amplifier 101c4 is also connected between the common port (COMM) of the uplink WSS 101c2 and the optical combiner 101c3, which is used to amplify the power of the combined optical signal to compensate for the losses caused by the uplink WSS 101c2, the optical combiner 101c3, and the optical link between them.

[0060] For the downstream WSS 101c2 in the local WSS module 101c, its tributary port (TRIB) is optically linked to the tributary port (TRIB) of the input WSS of the external WSS module 101a; the common port (COMM) is connected to the optical splitter 101c5. The downstream WSS 101c2 can receive the optical signal output from the tributary port (TRIB) of the input WSS of the external WSS module 101a, and output the optical signal to the optical splitter 101c5 after wavelength selection; the optical splitter 101c5 is used to perform power equalization on the optical signal output from the downstream WSS 101c2 before outputting it to the optical receiver.

[0061] The optical splitter 101c5 can be a 1*N optical coupler, where N represents the number of output terminals of the optical coupler, and its specific value can be flexibly set according to the number of optical receivers. Furthermore, an optical amplifier 101c6 is connected between the common port (COMM) of the downstream WSS 101c2 and the optical splitter 101c5. This amplifier amplifies the optical signal output from the downstream WSS 101c2 and outputs the amplified optical signal to the optical splitter 101c5 to compensate for losses caused by the downstream WSS 101c2, the optical splitter 101c5, and the optical link between them.

[0062] Optionally, for each external WSS module 101a, the common port (COMM) of its inlet WSS and outlet WSS 20b2 is connected to an optical amplifier (such as... Figure 2 and Figure 3 (As shown in the triangle). The optical amplifier connected to the ingress WSS amplifies the optical signal received from the optical link to compensate for line losses caused by the optical link, and then transmits the amplified optical signal to the ingress WSS. The optical amplifier connected to the common port of the egress WSS in the external WSS module 101a amplifies the optical signal output from the egress WSS to compensate for losses caused by the egress WSS and the internal optical link of the ROADM. Optionally, the optical amplifier connected to the common port (COMM) of the egress WSS in the external WSS module 101a can amplify the optical signal to the required power level, and then send the amplified optical signal to the optical link for transmission to the ingress WSS in another network element connected to the egress WSS.

[0063] The above implementation of ADG 101b is merely illustrative and does not constitute a limitation.

[0064] In the embodiments of this application, each WSS can forward a specified wavelength from a specified input port to a specified output according to actual needs, thereby realizing the wavelength forwarding function. Moreover, each WSS also has the function of inter-wavelength power balancing. The complexity of the WSS is determined by the number of reconfigurable wavelengths and the number of input and output ports.

[0065] The ingress WSS can be understood as a band deaggregator, which separates the optical signal received at the common port (COMM) of the ingress WSS into optical signals of multiple bands; and outputs the optical signals of different bands from designated tributary ports (TRIB). The egress WSS can be understood as a band aggregator, which aggregates the optical signals of multiple bands received at the tributary port (TRIB) of the egress WSS; and outputs the aggregated optical signal from its common port (COMM). The aggregated optical signal covers multiple bands.

[0066] The above description is merely an illustrative example of the structure of the optical transmission network provided in the embodiments of this application, and does not imply that the optical transmission network must include... Figure 2 and Figure 3 The inclusion of all the devices shown does not imply that an optical transmission network can only include... Figure 2 and Figure 3 The components shown.

[0067] To improve the relative stability of the system performance of optical transmission networks, in the embodiments of this application, such as Figure 2 As shown, idle channels in an optical transmission network can be loaded with noise signals, such as spontaneously radiated noise (ASE). The noise signal transmitted through the idle channel can cover the communication frequency band supported by the idle channel, but not the communication frequency band supported by the channels already used by the optical transmission network. For example, assuming the entire communication frequency band of the optical transmission network is the C+L band, in... Figure 2 In the optical transmission network, the channels already in use are MC1-MC4; correspondingly, the spectrum of noise signals transmitted through the idle channels covers other frequency bands in the C+L band besides the communication frequency bands supported by MC1-MC4.

[0068] In the embodiments of this application, such as Figure 2 As shown, noise signals can be loaded into the idle tributary ports (such as tributary port 4) of the output WSS of the external WSS module 101a. Here, an idle tributary port refers to a tributary port in the WSS that is not connected to other devices, such as... Figure 2 The diagram shows tributary ports 2 and 4, etc. In practical engineering applications, a specific tributary port of the outgoing WSS can be designated as the port for loading noise signals. The outgoing WSS can establish an optical transmission medium channel (MC) between the noise-loaded tributary port (TRIB) and the common port (COMM), and configure the communication frequency band of this optical transmission medium channel to cover the communication frequency band of idle channels in the optical transmission network, but excluding the communication frequency band supported by channels already used by the optical transmission network. In this way, the outgoing WSS can perform band aggregation of the noise in the optical transmission medium channel with the optical signals transmitted in other optical transmission medium channels; and output the aggregated optical signal to the optical link connected to other network elements, thereby realizing noise loading in idle channels.

[0069] In this embodiment, the network element controller 20 can sense the state of the optical transmission network and, when a fault is sensed in the optical transmission network, determine the channel affected by the fault and perform noise loading control on the channel affected by the fault, so that the spectrum of the noise signal loaded on the channel affected by the fault has the same frequency band range as the communication frequency band of the channel.

[0070] In this embodiment, the specific implementation of the network element controller 20 sensing 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 the optical link of the optical transmission network. In this embodiment, the specific location and number of fault monitoring units are not limited. Optionally, multiple fault monitoring units can be set according to the actual spatial granularity of monitoring. For example, a fault monitoring unit can be set on each optical link of the optical transmission network. The fault monitoring unit is used to monitor the power of the optical link; and when the detected optical power is less than or equal to a set power threshold, it provides a no-light warning (LOS) to the network element controller corresponding to the target network element to which the fault monitoring unit belongs. Accordingly, the network element controller corresponding to the target network element determines that a fault in the optical transmission network has been sensed upon receiving the no-light warning.

[0071] In this application, the specific implementation 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 minitor (OCM). The optical channel minitor is used to perform a spectral scan on its optical link to obtain the scanned spectral power; and to monitor the power of the optical link using the spectral power. Further, if the scanned spectral power is less than or equal to a set power threshold, a no-light warning is sent to the network element controller 20 corresponding to the target network element. The network element controller 20 corresponding to the target network element can determine that a fault has occurred in the optical transmission network upon receiving the no-light warning.

[0072] In this embodiment, there is no limitation on which optical links deploy optical power monitors or which optical links deploy optical channel monitors. Optionally, optical power monitors can be deployed on intermediate transmission links in the optical transmission network; optical channel monitors can be deployed on the uplink optical links of ADG 101b. Of course, optical power monitors can also be deployed on the uplink optical links of ADG 101b.

[0073] Furthermore, the network element controller 20 can identify the faulty optical link. In some embodiments, the no-light warning includes the identifier 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 uniquely identifies a monitored unit, such as a monitored device identifier and port number. The monitored device identifier can be a device name or a device IP address.

[0074] The network element controller 20 pre-stores the topology information of the optical transmission network. This topology information includes the names, identifiers, ports, and connections between the various devices within the network. The connections between devices can be described by their identifiers, names, and port numbers. For example, the connection could be described as an optical connection between the common port (COMM) of a WSS (identified as X) and the input of an optical amplifier (identified as Y). Based on this topology information, when identifying a faulty optical link, the network element controller 20 can obtain the identifier of the monitored unit from the no-light warning and determine the faulty optical link based on the identifier of the monitored unit and the pre-stored topology information. For example, the optical link sending the transmitted optical signal to the monitored unit can be identified as the faulty optical link based on the identifier of the monitored unit and the topology information of the optical transmission network.

[0075] In some embodiments, such as Figure 4 As shown, the WSS (WSS-I) can be accessed at the network element 10. i A fault monitoring unit is deployed on the optical link corresponding to the common port (COMM) of the ingress WSS (WSS-I). i The input optical power of ) at the input WSS (WSS-I) of network element 10. i Deploying a fault monitoring unit on the optical link corresponding to the common port (COMM) of the ingress WSS (WSS-I) may include: i A fault monitoring unit can be deployed at the inlet of the optical amplifier connected to the common port (COMM) of network element 10, or at the inlet of the WSS (WSS-I). i Fault monitoring units are deployed at the common port (COMM) of the optical amplifier. Specifically, the input of the optical amplifier is optically connected to the common port (COMM) of the output WSS in the upstream network element; the output of the optical amplifier is optically connected to the input WSS (WSS-I). i The common port (COMM) optical connection.

[0076] For this fault monitoring unit, when the optical link between the common port (COMM) of the ingress WSS and other network elements fails, the fault monitoring unit can trigger a no-light warning. Based on this, when the identifier of the monitored unit includes the common port (COMM) of the ingress WSS of the target network element, the network element controller 20 can determine the upstream network element connected to the ingress WSS of the target network element according to the topology information of the optical transmission network; and determine that the optical link connecting the upstream network element and the target network element is a faulty optical link. For example, such as... Figure 4 As shown, the identifier of the monitored unit includes the common port (COMM) of the ingress WSS (WSS-I2) numbered NE-B. Furthermore, the network element controller 20 can determine, based on the topology information of the optical transmission network, that the upstream network element connected to the ingress WSS (WSS-I2) is network element 10 numbered NE-A. Furthermore, it can be determined that the optical link connecting network element 10 numbered NE-A and network element 10 numbered NE-B is a faulty optical link.

[0077] In other embodiments, such as Figure 5 As shown, the WSS (WSS-E) can be accessed at the network element 10. i A fault monitoring unit is deployed at the branch port of the circuit; this fault monitoring unit is used to monitor the exit WSS (WSS-E). i The input optical power of the tributary port (TRIB) of the network element 10. Correspondingly, when the optical link connecting the outgoing WSS and the incoming WSS within the same network element 10 fails, or when the optical link between this network element and its upstream network element fails, the fault monitoring unit at the tributary port of the outgoing WSS triggers a no-light warning. For example, as... Figure 5 As shown, when the optical link between the egress WSS (WSS-E3) and the ingress WSS (WSS-I2) located in the same network element fails, or when the optical link between the ingress WSS (WSS-I2) and the network element numbered NE-A fails, the fault monitoring unit deployed at the tributary port (TRIB) of the egress WSS (WSS-E3) issues a no-light warning to the network element controller 20.

[0078] Since both intra-network element optical link failures and inter-network element optical link failures trigger the fault monitoring unit at the tributary port (TRIB) of the egress WSS to issue a no-light warning, when the monitored unit included in the no-light warning is the tributary port (TRIB) of the egress WSS, the network element controller 20 can perform intra-network element fault verification on the target network element; and if the verification result is an intra-network element optical link failure, it determines the optical link within the target network element connected to the tributary port (TRIB) of the egress WSS included in the no-light warning based on the topology information of the optical transmission network; and determines that the optical link within the target network element is a faulty optical link. For example, as... Figure 5As shown, in the case where there is no light warning, the tributary port 1 containing the outgoing WSS (WSS-E3) can determine, based on the topology information of the optical transmission network, that the optical link within the target network element connected to the tributary port 1 of the outgoing WSS (WSS-E3) is the optical link between the outgoing WSS (WSS-E3) and the incoming WSS (WSS-I2); furthermore, it can be determined that the optical link between the outgoing WSS (WSS-E3) and the incoming WSS (WSS-I2) is a faulty optical link.

[0079] In this application embodiment, the specific implementation method for fault verification within a network element is not limited. In some embodiments, fault monitoring units can be deployed at both ends of the optical link within a network element. For example, for the tributary port (TRIB) of the ingress WSS and the tributary port (TRIB) of the egress WSS connected by an optical link within the same network element, fault monitoring units can be set at the tributary port (TRIB) of the ingress WSS and the tributary port (TRIB) of the egress WSS respectively. When the optical link within the network element fails, the fault monitoring unit on the optical link connected to the tributary port (TRIB) of the ingress WSS can still monitor the optical power and will not issue a no-light warning. When the optical link between network elements fails, a no-light warning will be issued. Based on this, the network element controller 20 can determine the identifier of the monitored unit included in the no-light warning when it receives a no-light warning; and if the monitored unit includes the tributary port (TRIB) of the egress WSS but does not include the tributary port (TRIB) of the ingress WSS, it can determine that the optical link within the network element is faulty.

[0080] Furthermore, the network element controller 20 can determine that the optical link connected to the monitored unit is a faulty optical link based on the topology information of the optical transmission network.

[0081] In some other embodiments, such as Figure 6 As shown, a fault monitoring unit can be deployed at the uplink port of the uplink / downlink unit 101b in network element 10. This fault monitoring unit is used to monitor the input optical power of the uplink port. Accordingly, when the uplink optical link fails, the fault monitoring unit at the uplink port of the uplink / downlink unit 101b triggers a no-light warning. For example, as... Figure 6 As shown, when the uplink optical link in the MC4 channel of the uplink / downlink unit 101b fails, the fault monitoring unit deployed at the uplink port of the uplink / downlink unit 101b corresponding to the uplink optical link in the MC4 channel sends a no-light warning to the network element controller 20.

[0082] Based on this, when the monitored unit included in the no-light warning includes the uplink port of the uplink unit 101b, the network element controller 20 determines the uplink optical link connected to the uplink port according to the topology of the optical transmission network; and determines that the uplink optical link connected to the port is a faulty optical link.

[0083] For optical transmission networks, an optical link failure does not affect the operation of upstream optical transmission equipment and the upstream optical link itself, but it will affect the optical transmission of downstream optical transmission equipment and the downstream optical link. In each network element of an optical transmission network, the egress WSS is used to transmit optical signals to downstream network elements. For example, for... Figures 4-6 In the optical transmission network shown, the egress WSS (WSS-E3) in network element 10, numbered NE-B, is used to transmit optical signals to the downstream network element, namely network element NE-C. To prevent the fault from propagating downstream, after identifying the faulty optical link, the network element controller 20 can also determine the target egress WSS affected by the faulty optical link and the tributary port (TRIB) of the target egress WSS affected by the faulty optical link from the target network element; furthermore, it can determine that the original channel of the tributary port (TRIB) of the target egress WSS affected by the faulty optical link is the target channel.

[0084] Optionally, the network element controller 20 can determine the downstream egress WSS of the faulty optical link based on the topology information of the optical transmission network; and determine the downstream egress WSS as the target egress WSS. Further, it can determine the tributary port (TRIB) on the target egress WSS that is connected to the faulty optical link, and identify it as the tributary port (TRIB) of the target egress WSS affected by the faulty optical link.

[0085] For example, for Figure 4 In the illustrated embodiment of an inter-element optical link failure, the failed optical link can be identified as the optical link connecting network element 10 (NE-A) and network element 10 (NE-B). Further, the network element controller 20 can determine the downstream exit WSS of the failed optical link as exit WSS numbered WSS-E3 based on the topology information of the optical transmission network. Optionally, the network element controller 20 can determine the downstream ingress WSS connected to the failed optical link as ingress WSS numbered WSS-I2 based on the topology information of the optical transmission network. Further, it can determine the exit WSS connected to the tributary port (TRIB) of ingress WSS numbered WSS-I2 as exit WSS numbered WSS-E3 based on the topology information of the optical transmission network. Further, it can determine that exit WSS numbered WSS-E3 is the downstream exit WSS connected to the failed optical link. Therefore, exit WSS-E3 is determined as the target exit WSS. Accordingly, it can also be determined that the branch port 1 of the outgoing WSS and the incoming WSS of WSS-E3 is the branch port (TRIB) affected by the faulty optical link.

[0086] For example, regarding Figure 5The embodiment of the optical link failure within the network element shown can determine the downstream exit WSS of the failed optical link connection as the exit WSS numbered WSS-E3 based on the topology information of the optical transmission network; and determine the exit WSS numbered WSS-E3 as the target exit WSS; and the tributary port 1 of the target exit WSS connected by the failed optical link is the tributary port (TRIB) of the target exit WSS affected by the failed optical link.

[0087] For example, regarding Figure 6 In the embodiment of the network element shown, the upstream optical link failure can be determined according to the topology information of the optical transmission network. The downstream exit WSS of the failed upstream optical link is identified as the exit WSS numbered WSS-E3, and the downstream exit WSS (exit WSS numbered WSS-E3) is identified as the target exit WSS. Furthermore, the tributary port 3 on the exit WSS numbered WSS-E3 that is connected to the failed upstream optical link is identified as the tributary port (TRIB) on the target exit WSS affected by the failed optical link.

[0088] Because the tributary port (TRIB) on the target egress WSS affected by the optical link has no optical signal input, the optical link failure will propagate downstream. In this embodiment, to improve system stability, after determining the target egress WSS affected by the faulty optical link and the tributary port (TRIB) of the affected target egress WSS, the network element controller 20 can control the target egress WSS to apply noise loading to the original channel of the tributary port (TRIB) affected by the faulty optical link. Accordingly, the target egress WSS can apply noise loading to the original channel of the tributary port (TRIB) affected by the faulty optical link.

[0089] Optionally, the network element controller 20 can pre-store the channel configuration information of the optical links within the corresponding target network element. Alternatively, the network element controller 20 can also query the optical transmission equipment in the corresponding target network element 10 to obtain the channel configuration information of the optical links within the target network element. The channel configuration information may include the communication frequency band of the channel transmitted in the optical link. Furthermore, the network element controller 20 can obtain the channel configuration information of the original channel of the tributary port (TRIB) of the target egress WSS affected by the faulty optical link from the channel configuration information of the optical links within the target network element.

[0090] Furthermore, the target egress WSS can switch the target spectrum in the same frequency band as the original channel of the tributary port (TRIB) affected by the aforementioned optical fault link in the noise signal to the common port (COMM) of the target egress WSS, thereby achieving noise loading on the original channel.

[0091] In this embodiment, for the egress WSS in the optical transmission network, idle tributary ports (TRIBs) can be pre-loaded with noise signals. For ease of description and distinction, the tributary port on the target egress WSS affected by a faulty optical link can be defined as the first tributary port; the tributary port on the target egress WSS loaded with noise can be defined as the second tributary port. During normal operation of the optical transmission network, the egress WSS can establish an optical transmission medium channel between the noise-loaded tributary port and the common channel (COMM), and configure the communication frequency band of this optical transmission medium channel to cover the communication frequency band of idle channels in the optical transmission network, but excluding the communication frequency band supported by channels already used by the optical transmission network. In this way, the egress WSS can perform band aggregation of the noise in the optical transmission medium channel with the optical signals transmitted by other optical transmission medium channels; and output the aggregated optical signal to the optical link connected to other network elements, thereby realizing noise loading of idle channels.

[0092] Based on this, when the target egress WSS loads noise onto the original channel of the first tributary port, it can delete the first optical transmission medium channel between the first tributary port and the common port (COMM); and configure the second optical transmission medium channel between the second tributary port and the common port (COMM) to have the same communication frequency band as the first optical transmission medium channel. In this way, the target spectrum in the noise signal that has the same frequency band as the original optical channel can be switched to the common port (COMM) of the target egress WSS through the second optical transmission medium channel, thus achieving noise loading onto the original channel of the first tributary port.

[0093] In this embodiment, the network element controller 20 can control the target egress WSS to load noise onto the original channel of the first tributary port via instructions. Specifically, the network element controller 20 can provide a channel switching instruction to the target egress WSS. This channel switching instruction includes: the identifier of the first tributary port, the identifier of the second tributary port, and the communication frequency band of the original signal of the first tributary port. In response to this instruction, the target egress WSS can delete the first optical transmission medium channel between the first tributary port and the common port (COMM); and configure the second optical transmission medium channel between the second tributary port and the common port (COMM) to have the same communication frequency band as the first optical transmission medium channel. Thus, through the second optical transmission medium channel, the target spectrum in the noise signal that has the same frequency band as the original channel of the first tributary port can be switched to the common port (COMM) of the target egress WSS, thereby achieving noise loading onto the original channel of the first tributary port.

[0094] In this embodiment, the network element controller acts as the control unit for channel noise loading, processing the channel noise loading logic of local network elements, thus localizing the channel noise loading logic. Compared to a scheme where noise loading is controlled by a centralized management unit, this reduces information transmission links, helps improve the timeliness and speed of channel noise loading, and consequently contributes to improving the stability of the optical transmission network.

[0095] In addition to providing a channel noise loading scheme, this application also provides a channel noise cancellation scheme. The channel noise cancellation method provided in this application embodiment is described below by way of example.

[0096] In this embodiment, channel noise cancellation can be performed by a network element controller as a control unit, or autonomously by the optical transmission equipment within the target network element. Accordingly, when the network element controller 20 corresponding to the target network element or the optical transmission equipment within the target network element senses that the optical transmission network fault has been restored, it can control the aforementioned target egress WSS to perform noise cancellation on the original channel of the first tributary port, thereby restoring the original channel communication.

[0097] In this application embodiment, the specific implementation of the optical transmission network fault recovery sensing by the network element controller 20 corresponding to the target network element or the optical transmission device within the target network element is not limited. In some embodiments, after the optical transmission network fault is recovered, if the optical power detected by the fault monitoring unit is greater than the aforementioned set power threshold, a no-light warning clearance message can be issued. The network element controller 20 corresponding to the target network element can determine that the optical transmission network fault has been recovered upon detecting the no-light warning clearance message. For example, the network element controller 20 corresponding to the target network element can determine that the optical transmission network fault has been recovered upon receiving the no-light warning clearance message within a set duration. The optical transmission device within the target network element can also determine that the optical transmission network fault has been recovered upon detecting the no-light warning clearance message, and so on.

[0098] Furthermore, the network element controller 20 corresponding to the target network element or the optical transmission equipment within the target network element can control the aforementioned target egress WSS to perform noise cancellation on the original channel of the first tributary port, restoring the original channel communication. Specifically, the target egress WSS can delete the configuration of the communication frequency band of the original channel of the first tributary port in the second optical transmission medium channel between the second tributary port and the common channel port (COMM), so that the second optical transmission medium channel no longer loads the target spectrum with the same frequency band as the original channel of the first tributary port. Furthermore, the target egress WSS can re-establish the first optical transmission medium channel between the first tributary port and the common channel port (COMM); and configure the communication frequency band of the re-established first optical transmission medium channel as the communication frequency band of the original channel.

[0099] In this embodiment, when the optical transmission network fails, after noise loading is applied to the original channel of the first tributary port, the network element controller 20 corresponding to the target network element or the optical transmission device in the target network element can set the first tributary port as an associated port of the second tributary port; and store the association relationship between the second tributary port and the first tributary port. The target egress WSS can, upon recovery of the optical transmission network failure, perform noise removal on the original channel of the first tributary port based on this association relationship, thereby restoring original channel communication.

[0100] Specifically, when the target egress WSS configures the communication frequency band of the re-established first optical transmission medium channel to the communication frequency band of the original optical channel, it can query the association relationship between the second tributary port and the first tributary port to determine the first tributary port associated with the second tributary port; and obtain the communication frequency band of the original channel of the first tributary port from the association relationship; furthermore, the communication frequency band of the re-established first optical transmission medium channel can be configured to the communication frequency band of the original channel.

[0101] For the optical transmission network provided in this application embodiment, in addition to the network element controller acting as the control unit for channel loading, a centralized management unit can also act as the control unit for channel loading. For example... Figure 7 As shown, a centralized management unit 30 is configured. The centralized management unit 30 is communicatively connected to each network element 10. For details regarding the communication connection between the centralized management unit 30 and the network element 10, please refer to the communication method between the network element controller 20 and the network element 10 described above; it will not be repeated here.

[0102] exist Figure 7 In the illustrated embodiment, the centralized management unit 30 can centrally control the channel noise loading of multiple network elements 10. When the optical transmission network fails, the fault monitoring unit can send a no-light warning to the centralized management unit. Accordingly, upon receiving the no-light warning, the centralized management unit determines that the optical transmission network has failed. Further, the centralized management unit 30 can obtain the identifier of the monitored unit contained in the no-light warning; and based on the identifier of the monitored unit and the pre-stored topology information of the optical transmission network, determine the faulty optical link. For a detailed implementation of how the centralized management unit 30 determines the faulty optical link, please refer to the relevant content of the network element controller 20 determining the faulty optical link in the above embodiment, which will not be repeated here.

[0103] Furthermore, the centralized management unit 30 can determine the target egress WSS affected by the faulty optical link and the first tributary port of the target egress WSS. For a detailed implementation of this process, please refer to the relevant content regarding the determination of the target egress WSS and the first tributary port of the target egress WSS by the network element controller described above, which will not be repeated here.

[0104] Furthermore, the centralized management unit 30 can control the target egress WSS to apply noise loading to the original channel of the first tributary port. For a specific implementation of the target egress WSS applying noise loading to the original channel of the first tributary port, please refer to the relevant content of the above embodiments, which will not be repeated here.

[0105] Of course, when the optical transmission network is restored from a fault, the centralized management unit 30 can also control the target egress WSS to clear noise from the original channel of the first tributary port. For specific implementation details, please refer to the above-mentioned content on the noise clearing of the original channel of the first tributary port by the network element controller, which will not be repeated here.

[0106] For schemes where channel noise loading and clearing are performed by a centralized management unit, it relies on multi-process interactions between the centralized management unit and various network elements, as well as end-to-end confirmation of the channel. Compared to schemes where channel noise loading and clearing are performed locally by network elements, the timeliness is poor, which to some extent affects the stability of the optical transmission network. Especially during the multi-process interactions, before channel noise loading, the faulty channel of the optical transmission network will be in a no-signal state. During this period, the use of channels in the optical transmission network is reduced, affecting the stability of the optical transmission network.

[0107] On the other hand, the channel noise loading and removal scheme of the centralized management unit relies on the robustness and reliability of the centralized management network and the centralized management unit. If the centralized management network and the centralized management unit fail or malfunction, the centralized management unit will be unable to load and remove noise from the optical transmission network, affecting its normal operation. Especially after the optical transmission network has recovered from a fault, if the centralized management network and the centralized management unit fail or malfunction, the noise in the original channel cannot be removed, preventing the restoration of normal communication and affecting the normal optical signal transmission of the optical transmission network.

[0108] Based on the above analysis, the scheme provided by the network element controller for loading and clearing channel noise on local network elements can reduce interaction processes and help improve the timeliness of channel noise loading and clearing. On the other hand, the scheme for loading and clearing channel noise on local network elements by the network element controller does not rely on the robustness and reliability of the centralized management network, which helps improve the robustness of channel noise loading and clearing.

[0109] For the aforementioned scheme where channel noise cancellation is implemented by optical transmission equipment within a network element, decentralizing the channel noise cancellation logic to the local optical transmission equipment can further reduce interaction processes and help improve the timeliness of channel noise cancellation. On the other hand, the scheme where channel noise cancellation is performed by optical transmission equipment does not rely on the robustness and reliability of the centralized management network, or even on communication between the network element controller and the network element, which helps to further improve the robustness of channel noise cancellation.

[0110] In addition to the optical transmission network provided in the above embodiments, this application also provides a method for channel noise loading and removal. The method for channel noise loading and removal is described exemplarily below.

[0111] Figure 8 This is a flowchart illustrating the channel noise loading method provided in an embodiment of this application. Figure 9 As shown, the channel noise loading method includes:

[0112] 801. In the event of a detected optical transmission network fault, identify the faulty optical link in the optical transmission network.

[0113] 802. Determine the target channel affected by the faulty optical link from the target network elements corresponding to the network element controller.

[0114] 803. Control the target network element to load noise onto the target channel.

[0115] In this embodiment, the optical transmission network includes multiple network elements; these network elements are optically connected. Each network element may have a corresponding network element controller. Each network element corresponds to one or more network element controllers and is communicatively connected to its corresponding network element controller. Each network element has an independent corresponding network element controller. For details regarding the structure of the optical transmission network, network elements, and the relationship between network elements and their controllers, please refer to the relevant content in the above system embodiments; further details will not be repeated here.

[0116] In this embodiment, the network element controller can sense the state of the optical transmission network, and in the event of a fault in the optical transmission network, in step 801, determine the faulty optical link in the optical transmission network; and in step 802, determine the target channel affected by the faulty optical link from the target network element corresponding to the network element controller; then, in step 803, control the target network element to perform noise loading control on the target channel, so that the spectrum of the noise signal loaded on the target channel has the same frequency band range as the communication frequency band of the channel, thereby realizing the channel noise loading of the local network element by the network element controller.

[0117] In this embodiment, the network element controller acts as the control unit for channel noise loading, which handles the channel noise loading of local network elements. Compared with the centralized management unit acting as the control unit for channel noise, this reduces the signal flow transmission process, helps improve the timeliness of channel loading, and thus helps improve system stability.

[0118] In the embodiments of this application, the specific implementation form of the network element is not limited. The channel noise loading method provided in the embodiments of this application will be specifically described below in conjunction with a specific network element structure.

[0119] In some embodiments, each network element includes a ROADM. In this embodiment, multiple network elements can be optically linked via a ROADM. For details regarding the specific structure of the ROADM, please refer to the relevant content in the above system embodiments; it will not be repeated here.

[0120] In this application embodiment, the specific implementation of the network element controller sensing the state of the optical transmission network is not limited. In some embodiments, a fault monitoring unit is provided on the optical link of the optical transmission network. The implementation of the light source fault monitor can be found in the relevant content of the above system embodiments, and will not be repeated here.

[0121] The fault monitoring unit is used to monitor the power of the optical link; and when the detected optical power is less than or equal to a set power threshold, it provides a no-light warning (LOS) to the network element controller corresponding to the target network element monitored by the fault monitoring unit. Accordingly, upon receiving the no-light warning, the network element controller corresponding to the target network element determines that a fault in the optical transmission network has been detected.

[0122] Furthermore, the faulty optical link can be identified. In some embodiments, the no-light warning includes an identifier of the monitored unit. For a description of the identifier of the monitored unit, please refer to the relevant content in the above-described optical transmission network embodiments, which will not be repeated here.

[0123] The network element controller pre-stores the topology information of the optical transmission network. Based on the topology information of the optical transmission network, when determining a faulty optical link, the network element controller can obtain the identifier of the monitored unit from the no-light warning; and determine the faulty optical link according to the identifier of the monitored unit and the pre-stored topology information of the optical transmission network.

[0124] Optionally, the identifier of the monitored unit can be used to match the topology information of the optical transmission network to identify the faulty optical link.

[0125] In some embodiments, such as Figure 4 As shown, WSS (WSS-I) can be accessed at the network element's entry point. i A fault monitoring unit is deployed at the common port (COMM) of the ingress WSS (WSS-I). i The input optical power of the fault monitoring unit is [not specified]. For this fault monitoring unit, when the optical link between the common port (COMM) of the ingress WSS and other network elements fails, the fault monitoring unit can trigger a no-light warning. Based on this, if the identifier of the monitored unit included in the no-light warning contains the optical link connected to the common port (COMM) of the target network element's ingress WSS, the network element controller can determine the upstream network element connected to the target network element's ingress WSS based on the topology information of the optical transmission network; and determine that the optical link connecting the upstream network element and the target network element is a faulty optical link.

[0126] In other embodiments, such as Figure 5 As shown, WSS (WSS-E) can be used at the network element's exit point. i A fault monitoring unit is deployed at the branch port (TRIB) of the ); this fault monitoring unit is used to monitor the outgoing WSS (WSS-E) i The input optical power of the tributary port (TRIB) of the network element. Accordingly, when the optical link connecting the outgoing WSS and the incoming WSS within the same network element fails, or when the optical link between the network element and its upstream network element fails, the fault monitoring unit at the tributary port (TRIB) of the outgoing WSS triggers a no-light warning.

[0127] Since both intra-network element optical link failures and inter-network element optical link failures trigger the fault monitoring unit at the tributary port (TRIB) of the egress WSS to issue a no-light warning, when the identifier of the monitored unit included in the no-light warning contains the tributary port (TRIB) of the egress WSS, the network element controller can perform intra-network element fault verification on the target network element; and if the verification result is an intra-network element optical link failure, the controller determines the optical link within the target network element connected to the tributary port (TRIB) of the egress WSS monitored by the target fault monitoring unit based on the topology information of the optical transmission network; and determines that the optical link within the target network element is a faulty optical link.

[0128] For details on the specific implementation of fault verification within the target network element, please refer to the relevant content of the above system embodiments, which will not be repeated here.

[0129] Furthermore, based on the topology information of the optical transmission network, the optical link connected to the tributary port (TRIB) monitored by the fault monitoring unit can be identified as a faulty optical link.

[0130] In some other embodiments, such as Figure 6 As shown, a fault monitoring unit can be deployed at the uplink port of the uplink / downlink unit of the network element. This fault monitoring unit is used to monitor the input optical power of the uplink port. Accordingly, when the uplink optical link fails, the fault monitoring unit at the uplink port (TRIB) of the uplink / downlink unit triggers a no-light warning.

[0131] Based on this, if the deployment location of the target fault monitoring unit that provides no light warning is determined to include the uplink port of the uplink unit, the uplink optical link connected to the uplink port can be determined according to the topology of the optical transmission network; and the uplink optical link connected to the port can be determined to be a faulty optical link.

[0132] For optical transmission networks, an optical link failure does not affect the operation of upstream optical transmission equipment and the upstream optical link itself, but it does affect the optical transmission of downstream optical transmission equipment and the downstream optical link. In each network element of the optical transmission network, the egress WSS is used to transmit optical signals to downstream network elements. To prevent the fault from propagating downstream, after identifying the faulty optical link, it is possible to determine the target egress WSS affected by the faulty optical link and the tributary ports of the target egress WSS affected by the faulty optical link from the target network element; furthermore, the original channel of the tributary port of the target egress WSS affected by the faulty optical link can be determined as the target channel.

[0133] Optionally, the downstream egress WSS of the faulty optical link can be determined based on the topology information of the optical transmission network; and the downstream egress WSS can be determined as the target egress WSS. Further, the tributary ports on the target egress WSS that are connected to the faulty optical link can be determined as the tributary ports of the target egress WSS affected by the faulty optical link.

[0134] Since the tributary ports on the target egress WSS affected by the optical link have no optical signal input, the optical link failure will propagate downstream. In this embodiment, to improve system stability, after determining the target egress WSS affected by the faulty optical link and the tributary ports of the affected target egress WSS, the target egress WSS can be controlled to apply noise loading to the original channel of the tributary ports affected by the faulty optical link. Accordingly, the target egress WSS can apply noise loading to the original channel of the tributary ports affected by the faulty optical link.

[0135] Optionally, channel configuration information of the optical link within the corresponding target network element can be pre-stored. This channel configuration information may include the communication frequency band of the channel transmitted in the optical link. Further, the channel configuration information of the original channel of the tributary port of the target egress WSS affected by the faulty optical link can be obtained from the pre-stored channel configuration information of the optical link within the target network element; and the original channel configuration information is provided to the target egress WSS to control the target egress WSS to switch the target spectrum in the noise signal that has the same frequency band as the original channel configuration information of the tributary port affected by the aforementioned optical faulty link to the common port of the target egress WSS, thereby achieving noise loading of the original channel.

[0136] Accordingly, the target exit WSS can switch the target spectrum in the noise signal that has the same frequency band as the original channel of the branch port affected by the aforementioned optical fault link to the common port of the target exit WSS, thereby realizing noise loading of the original channel.

[0137] In this embodiment, for the egress WSS in the optical transmission network, idle tributary ports can be pre-loaded with noise signals. For ease of description and distinction, the tributary port on the target egress WSS affected by a faulty optical link can be defined as the first tributary port; the tributary port on the target egress WSS loaded with noise can be defined as the second tributary port. During normal operation of the optical transmission network, the egress WSS can establish an optical transmission medium channel between the noise-loaded tributary port and the common port, and configure the communication frequency band of this optical transmission medium channel to cover the communication frequency band of idle channels in the optical transmission network, but excluding the communication frequency band supported by channels already used by the optical transmission network. In this way, the egress WSS can perform band aggregation of the noise in the optical transmission medium channel with the optical signals transmitted by other optical transmission medium channels; and output the aggregated optical signal to the optical link connected to other network elements, thereby realizing noise loading of idle channels.

[0138] Based on this, when the target egress WSS loads noise onto the original channel of the first tributary port, it can delete the first optical transmission medium channel between the first tributary port and the common port; and configure the second optical transmission medium channel between the second tributary port and the common port to have the same communication frequency band as the first optical transmission medium channel. In this way, the target spectrum in the noise signal that has the same frequency band as the original optical channel can be switched to the common port of the target egress WSS through the second optical transmission medium channel, thus achieving noise loading onto the original channel of the first tributary port.

[0139] In this embodiment, the target egress WSS can be controlled by instructions to load noise onto the original channel of the first tributary port. Specifically, the network element controller can provide a channel switching instruction to the target egress WSS. This channel switching instruction includes: the identifier of the first tributary port, the identifier of the second tributary port, and the communication frequency band of the original signal of the first tributary port. In response to this instruction, the target egress WSS can delete the first optical transmission medium channel between the first tributary port and the common port; and configure the second optical transmission medium channel between the second tributary port and the common port to have the same communication frequency band as the first optical transmission medium channel. Thus, through the second optical transmission medium channel, the target spectrum in the noise signal that has the same frequency band as the original channel of the first tributary port can be switched to the common port of the target egress WSS, thereby achieving noise loading onto the original channel of the first tributary port.

[0140] In this embodiment, the network element controller acts as the control unit for channel noise loading, processing the channel noise loading logic of local network elements, thus localizing the channel noise loading logic. Compared to a scheme where noise loading is controlled by a centralized management unit, this reduces information transmission links, helps improve the timeliness and speed of channel noise loading, and consequently contributes to improving the stability of the optical transmission network.

[0141] In addition to providing a channel noise loading scheme, this application also provides a channel noise cancellation method. The channel noise cancellation method provided in this application embodiment is described below by way of example.

[0142] Figure 9 This is a flowchart illustrating the channel noise cancellation method provided in an embodiment of this application. Figure 9 As shown, the channel noise cancellation method includes:

[0143] 901. Record the target channel with noise loading in the target network element when the optical transmission network fails.

[0144] 902. Upon sensing that the optical transmission network has recovered from a fault, control the target network element to perform noise removal on the target channel.

[0145] In this embodiment, channel noise removal can be performed by a network element controller as a control unit, or autonomously by the optical transmission equipment within the target network element. Accordingly, when the network element controller corresponding to the target network element or the optical transmission equipment within the target network element senses that the optical transmission network fault has been restored, it can control the target network element to remove noise from the target channel loaded with noise in the target network element and restore the target channel communication.

[0146] Specifically, the target output WSS can be controlled to clear noise from the original channel of the first branch port and restore the original channel communication.

[0147] In this application embodiment, the specific implementation form of sensing optical transmission network fault recovery by the network element controller corresponding to the target network element or the optical transmission device within the target network element is not limited. In some embodiments, after the optical transmission network fault is recovered, if the optical power detected by the fault monitoring unit is greater than the aforementioned set power threshold, a no-light warning clearing message is issued. The network element controller corresponding to the target network element can determine that the optical transmission network fault has been recovered upon detecting the no-light warning clearing message. For example, the network element controller corresponding to the target network element can determine that the optical transmission network fault has been recovered if it continuously receives the no-light warning clearing message for a set duration. The optical transmission device within the target network element can also determine that the optical transmission network fault has been recovered upon detecting the no-light warning clearing message, and so on.

[0148] Furthermore, the network element controller corresponding to the target network element or the optical transmission equipment within the target network element can control the aforementioned target egress WSS to perform noise cancellation on the original channel of the first tributary port, restoring the original channel communication. Specifically, the target egress WSS can delete the configuration of the communication frequency band of the original channel of the first tributary port in the second optical transmission medium channel between the second tributary port and the common port, so that the second optical transmission medium channel no longer loads the target spectrum with the same frequency band as the original channel of the first tributary port. Furthermore, the target egress WSS can re-establish the first optical transmission medium channel between the first tributary port and the common port; and configure the communication frequency band of the re-established first optical transmission medium channel as the communication frequency band of the original channel.

[0149] In this embodiment, when the optical transmission network fails, after noise loading is applied to the original channel of the first tributary port, the network element controller corresponding to the target network element or the optical transmission device in the target network element can set the first tributary port as an associated port of the second tributary port; and store the association relationship between the second tributary port and the first tributary port. The target egress WSS can, upon recovery of the optical transmission network failure, perform noise removal on the original channel of the first tributary port based on this association relationship, thereby restoring original channel communication.

[0150] Specifically, when the target egress WSS configures the communication frequency band of the re-established first optical transmission medium channel to the communication frequency band of the original optical channel, it can query the association relationship between the second tributary port and the first tributary port to determine the first tributary port associated with the second tributary port; and obtain the communication frequency band of the original channel of the first tributary port from the association relationship; furthermore, the communication frequency band of the re-established first optical transmission medium channel can be configured to the communication frequency band of the original channel.

[0151] In this embodiment, decentralizing the channel noise cancellation logic to the local optical transmission equipment further reduces the interaction process and helps to improve the timeliness of channel noise cancellation. On the other hand, the scheme of performing channel noise cancellation by the optical transmission equipment does not rely on the robustness and reliability of the centralized management network, or even on the communication between the network element controller and the network element, which helps to further improve the robustness of channel noise cancellation.

[0152] The following uses three fault scenarios—inter-network element optical link failure, intra-network element optical link failure, and on-line optical link failure—as examples to illustrate the channel noise loading and channel noise removal methods provided in this application.

[0153] Application Scenario 1: Inter-network element faults

[0154] Figure 10 This is a flowchart illustrating a noise loading method for inter-network element optical link failures provided in an embodiment of this application. Figure 10As shown, noise loading methods may include:

[0155] S11, Optical link failure between network elements.

[0156] S12. A faulty optical link triggers the automatic shutdown of the downstream optical amplifier of the faulty optical link.

[0157] S13. The fault monitoring unit of the downstream network element of the faulty optical link issues a no-light warning.

[0158] S14. When the network element controller of the downstream network element of the faulty optical link receives the no-light warning, it determines that the optical transmission network is faulty.

[0159] S15. Based on the no-light warning and the topology information of the optical transmission network, determine the target egress WSS affected by the optical fault link and the first branch port affected by the optical fault link from the downstream network elements of the faulty optical link.

[0160] S16. Delete the first optical transmission medium channel between the first branch port and the common port of the target output WSS.

[0161] S17. Configure the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target output WSS to have the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band with the same frequency band range as the original channel of the first branch port to the common port of the target output WSS through the second optical transmission medium channel.

[0162] S18. Set the first branch port as the associated port of the second branch port.

[0163] Accordingly, such as Figure 11 As shown, the noise cancellation method during optical link fault recovery between network elements may include:

[0164] S21. Restoration of optical links between network elements.

[0165] S22. The downstream optical amplifier of the faulty optical link is automatically turned on.

[0166] S23. The fault monitoring unit of the downstream network element of the faulty optical link receives the no-light warning clear message; the network element controller corresponding to the downstream network element of the faulty optical link receives the no-light warning clear message and determines that the optical transmission network has been restored.

[0167] S24. Determine whether the associated port of the second tributary port includes the first tributary port. If the determination result is yes, proceed to step S25; if the determination result is no, end the noise clearing operation during the recovery of the optical link fault between network elements.

[0168] S25. Delete the frequency band configuration of the original channel of the second optical transmission medium channel with respect to the first tributary port.

[0169] S26. Re-establish the first optical transmission medium channel between the first branch port and the common port of the target output WSS.

[0170] S27. Configure the communication frequency band of the first optical transmission medium channel as the original channel communication frequency band of the first tributary port.

[0171] Application Scenario 2: Optical Link Failure within Network Element

[0172] Figure 12 This is a flowchart illustrating a noise loading method for an intra-network optical link failure provided in an embodiment of this application. Figure 12 As shown, noise loading methods may include:

[0173] S31, Optical link failure within network element.

[0174] S32. The fault monitoring unit at the first branch port of the downstream exit WSS of the faulty optical link issues a no-light warning.

[0175] S33. The network element controller corresponding to the network element receives a no-light warning and determines that there is a fault in the optical transmission network.

[0176] S34. Verify whether the optical transmission fault is an optical link fault within the network element. If the verification result is yes, proceed to step S35; if the result is no, end the noise loading operation during the recovery of the optical link fault within the network element.

[0177] S35. Delete the first optical transmission medium channel between the first branch port and the common port of the target output WSS.

[0178] S36. Configure the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target output WSS to have the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band with the same frequency band range as the original channel of the first branch port to the common port of the target output WSS through the second optical transmission medium channel.

[0179] S37. Set the first branch port as the associated port of the second branch port.

[0180] Accordingly, such as Figure 13 As shown, the noise cancellation method during optical link fault recovery within a network element may include:

[0181] S41. Intra-network element optical link recovery.

[0182] S42. The fault monitoring unit at the first branch port of the downstream exit WSS of the faulty optical link sends a no-light warning clear message; the network element controller corresponding to the network element receives the no-light warning clear message and determines that the optical transmission network has been restored.

[0183] S43. Determine whether the associated port of the second tributary port includes the first tributary port. If the determination result is yes, proceed to step S44; if the determination result is no, end the noise clearing operation during the recovery of the optical link fault between network elements.

[0184] S44. Delete the frequency band configuration of the original channel of the second optical transmission medium channel with respect to the first tributary port.

[0185] S45. Re-establish the first optical transmission medium channel between the first tributary port and the common port of the target exit WSS.

[0186] S46. Configure the communication frequency band of the first optical transmission medium channel to be the original channel communication frequency band of the first tributary port.

[0187] Application Scenario 3: On-line optical link failure

[0188] Figure 14 This is a flowchart illustrating the noise loading method for an uplink optical link failure provided in an embodiment of this application. Figure 14 As shown, noise loading methods may include:

[0189] S51, Uplink optical link failure.

[0190] S52. The fault monitoring unit at the uplink port of the uplink unit in the downstream network element of the uplink optical link issues a no-light warning.

[0191] S53. The network element controller corresponding to the downstream network element of the uplink optical link receives a no-light warning and determines that there is a fault in the optical transmission network.

[0192] S54. Based on the no-light warning and the topology information of the optical transmission network, determine the target egress WSS affected by the optical fault link and the first tributary port affected by the optical fault link from the downstream network elements of the upstream optical link.

[0193] S55. Delete the first optical transmission medium channel between the first branch port and the common port of the target output WSS.

[0194] S56. Configure the second optical transmission medium channel between the second branch port loaded with the noise signal and the common port of the target output WSS to have the same communication frequency band as the first optical transmission medium channel, so as to load the target frequency band with the same frequency band range as the original channel of the first branch port to the common port of the target output WSS through the second optical transmission medium channel.

[0195] S57. Set the first branch port as the associated port of the second branch port.

[0196] Accordingly, such as Figure 15As shown, for an embodiment where an optical power detector is installed at the uplink port of the uplink / downlink unit, the noise cancellation method during uplink optical link fault recovery may include:

[0197] S61, Uplink optical link restored.

[0198] S62. The fault monitoring unit at the uplink port of the uplink unit in the downstream network element of the uplink optical link sends a no-light warning clear message; the network element controller corresponding to the downstream network element of the uplink optical link receives the no-light warning clear message.

[0199] S63. Determine whether the fault monitoring unit of the uplink and downlink units has issued a no-light warning; if the determination result is no, proceed to step S64; if the determination result is yes, end the noise clearing operation when the optical link between network elements is restored.

[0200] S64. Determine whether the associated port of the second tributary port includes the first tributary port. If the determination result is yes, proceed to step S65; if the determination result is no, end the noise clearing operation during the recovery of the optical link fault between network elements.

[0201] S65. Delete the frequency band configuration of the original channel of the second optical transmission medium channel with respect to the first tributary port.

[0202] S66. Re-establish the first optical transmission medium channel between the first tributary port and the common port of the target exit WSS.

[0203] S67. Configure the communication frequency band of the first optical transmission medium channel as the original channel communication frequency band of the first tributary port.

[0204] Accordingly, such as Figure 16 As shown, for an embodiment where an optical channel detector is installed at the uplink port of the uplink / downlink unit, the noise cancellation method during uplink optical link fault recovery may include:

[0205] S71, Uplink optical link restored.

[0206] S72. The optical channel detector at the upper port of the upper and lower units performs periodic spectral scanning; if optical power recovery is detected, the upper optical link recovery is determined.

[0207] S73. Determine whether the associated port of the second tributary port includes the first tributary port. If the determination result is yes, proceed to step S74; if the determination result is no, end the noise clearing operation during the recovery of the optical link fault between network elements.

[0208] S74. Delete the frequency band configuration of the original channel of the second optical transmission medium channel with respect to the first tributary port.

[0209] S75. Re-establish the first optical transmission medium channel between the first branch port and the common port of the target output WSS.

[0210] S76. Configure the communication frequency band of the first optical transmission medium channel as the communication frequency band of the original channel of the first tributary port.

[0211] It should be noted that the execution subject of each step of the method provided in the above embodiments can be the same device, or the method can be executed by different devices. For example, the execution subject of steps 801 and 802 can be device A; or the execution subject of step 801 can be device A, and the execution subject of step 802 can be device B; and so on.

[0212] Furthermore, some processes described in the above embodiments and accompanying drawings include multiple operations that appear in a specific order. However, it should be clearly understood that these operations may not be executed in the order they appear herein, or they may be executed in parallel. The operation numbers, such as 801, 802, etc., are merely used to distinguish different operations and do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations may be executed sequentially or in parallel.

[0213] Accordingly, embodiments of this application also provide a computer-readable storage medium storing computer instructions, which, when executed by one or more processors, cause one or more processors to perform the steps in the above-described noise loading and / or noise removal methods.

[0214] It should be noted that the terms "first" and "second" in this article are used to distinguish different messages, devices, modules, etc., and do not represent a chronological order, nor do they limit "first" and "second" to different types.

[0215] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can 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, etc.) containing computer-usable program code.

[0216] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can 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, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0217] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0218] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0219] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0220] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0221] Computer storage media are readable storage media, also known as removable media. Removable and non-removable media can be used to store information by any method or technology. Information can be computer-readable instructions, data structures, program modules, 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media do not include transient media, such as modulated data signals and carrier waves.

[0222] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0223] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. An optical transport network, characterized by, The method comprises the following steps: a plurality of network elements and a plurality of network element controllers corresponding to the plurality of network elements respectively; the plurality of network element controllers are in communication connection with the respective corresponding network elements; the plurality of network elements are in optical connection; a fault monitoring unit is arranged on an optical link of the optical transmission network; the fault detection unit is used for power monitoring of the optical link; and in the case that the detected optical power is less than or equal to a set power threshold, providing a no-light warning to the network element controller corresponding to the target network element to which the fault monitoring unit belongs; the no-light warning includes the identification of the monitored unit; the network element controller is used for: in the case that the no-light warning is received, determining that the optical transmission network failure is sensed, and obtaining the identification of the monitored unit from the no-light warning; determining the fault optical link according to the identification of the monitored unit and the topology structure information of the optical transmission network; the topology structure information includes the identification of each device contained in the optical transmission network, the port and the connection relationship between the ports; determining the target channel affected by the fault optical link from the target network element corresponding to the network element controller; controlling the target network element to load noise on the target channel; wherein the frequency spectrum of the noise signal loaded on the target channel has the same frequency band range as the communication frequency band of the target channel.

2. The network of claim 1, wherein, Each network element comprises a reconfigurable optical add-drop multiplexer (ROADM); the plurality of network elements are in optical connection through the ROADM; the ROADM comprises 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 in optical connection with the external WSS module in other ROADM through the inlet WSS and the outlet WSS; when determining the target channel affected by the fault optical link, the network element controller is specifically used for: determining the target outlet WSS affected by the fault optical link and the first branch port of the target outlet WSS from the target network element; determining the original channel of the first branch port as the target channel.

3. The network of claim 2, wherein, when loading noise on the target channel of the first branch port, the target network element is specifically used for: the target outlet WSS switches the target spectrum in the noise signal having the same frequency band as the original channel to the common port of the target outlet WSS to load noise 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 used for: in the case that the optical transmission network failure recovery is sensed, controlling the target outlet WSS to remove noise on the original channel.

5. A noise loading method, applicable to a network element controller in an optical transport network, characterized in that, The optical transmission network comprises: a plurality of network elements and a plurality of network element controllers corresponding to the plurality of network elements respectively; the plurality of network element controllers are in communication connection with the respective corresponding network elements; the plurality of network elements are optically connected; a fault monitoring unit is arranged on an optical link of the optical transmission network; the fault detection unit is used for power monitoring of the optical link; and in the case that the detected optical power is less than or equal to a set power threshold, a no-light warning is provided to the network element controller corresponding to the target network element to which the fault monitoring unit belongs; the no-light warning comprises an identifier of the monitored unit; The method comprises: In the case that the no-light warning issued by the fault monitoring unit is received, it is determined that the optical transmission network failure is sensed; From the no-light warning, the identifier of the monitored unit is acquired; According to the identifier of the monitored unit and the topology structure information of the optical transmission network, a fault optical link in the optical transmission network is determined; the topology structure information comprises: the identifier of each device contained in the optical transmission network, the port and the connection relationship between the ports; From the target network element corresponding to the network element controller, a target channel affected by the fault optical link is determined; The target network element is controlled to load noise on the target channel; wherein the frequency spectrum of the noise signal loaded on the target channel has the same frequency band range as the communication frequency band of the target channel.

6. The method of claim 5, wherein, The target channel affected by the fault optical link is determined from the target network element corresponding to the network element controller, comprising: From the target network element, a target exit WSS affected by the fault optical link and a first branch port of the target exit WSS are determined; The original channel of the first branch port is determined as the target channel.

7. The method of claim 6, wherein, The target network element is controlled to load noise on the target channel, comprising: The target exit WSS is controlled to switch the target spectrum in the noise signal having the same frequency band as the original channel to the common port of the target exit WSS, so as to control the target network element to load noise on the target channel.

8. The method of claim 5, wherein, The target exit WSS affected by the fault optical link and the first branch port of the target exit WSS are determined from the target network element, comprising: According to the topology structure information, a downstream exit WSS of the fault optical link is determined; The downstream exit WSS is determined as the target exit WSS; and a branch port connected with the fault optical link on the target exit WSS is determined as the first branch port.

9. The method according to any one of claims 5-8, characterized in that, Further comprising: In the case that the optical transmission network failure recovery is sensed, the target network element is controlled to clear noise on the target channel.

10. The method of claim 9, wherein, The target network element is controlled to clear noise on the target channel, comprising: The target exit WSS affected by the fault optical link is controlled to delete the communication frequency band configuration of the target channel in the second optical transmission medium channel; the second optical transmission medium channel is an optical transmission medium channel between the second branch port of the target exit WSS loaded with the noise signal and the common port of the target exit WSS. reestablishing a first optical transmission medium channel between the first tributary port of the target egress WSS and the common port of the target egress WSS; configuring the communication frequency band of the reestablished first optical transmission medium channel as the communication frequency band of the original channel of the first tributary port.

11. The method of claim 10, wherein, Further comprising: setting the first tributary port as the associated port of the second tributary port after noise loading on the original channel of the first tributary port; storing the association relationship between the second tributary port and the first tributary port; the target egress 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: query the association relationship to determine the first tributary port associated with the second tributary port; obtain the communication frequency band of the original channel from the association relationship; configure the communication frequency band of the reestablished first optical transmission medium channel as the communication frequency band of the original channel.

12. A method of noise cleaning, applicable to a network element controller in an optical transport network, characterized in that, The optical transmission network comprises a plurality of network elements and a plurality of network element controllers corresponding to the plurality of network elements respectively; the plurality of network element controllers are in communication connection with the respective corresponding network elements; the plurality of network elements are optically connected; a fault monitoring unit is arranged on the optical link of the optical transmission network; the fault detection unit is used for power monitoring of the optical link; and in the case that the detected optical power is less than or equal to a set power threshold, a no-light warning is provided to the network element controller corresponding to the target network element to which the fault monitoring unit belongs; the no-light warning includes the identification of the monitored unit; in the case that the monitored power is greater than the set power threshold, a no-light warning clearing message is sent to the network element controller corresponding to the target network element; the method comprises: recording a target channel of noise loading in a target network element when the optical transmission network fails; the target channel is a channel affected by the optical transmission network failure; the fault optical link where the target channel is located is determined by the network element controller according to the identification of the monitored unit and the topology structure information of the optical transmission network; the topology structure information includes the identification, ports and connection relationship between the ports of each device included in the optical transmission network; wherein the frequency spectrum of the noise signal loaded by the target channel has the same frequency band range as the communication frequency band of the target channel; in the case that the no-light warning clearing message is monitored, it is determined that the optical transmission network failure is recovered; in the case that the optical transmission network failure recovery is sensed, the target network element is controlled to perform noise cleaning on the target channel.

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