A method for processing amplifier spontaneous emission noise and an optical fiber transmission network

Abstract

The present application discloses a method for processing amplifier spontaneous emission noise and an optical fiber transmission network. The method includes: obtaining at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer ROADM; obtaining a first frequency range occupied by all wavelength channels in the at least one wavelength channel; removing the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; filling amplifier spontaneous emission ASE noise in the second frequency range. By means of the present application, the problem that the link needs to be adjusted when the optical fiber network changes from light load to heavy load, thereby affecting the system performance, is solved. Furthermore, network fluctuations from light load to heavy load can be avoided by filling ASE noise, and the system stability is improved.

Description

Technical Field

[0001] This application relates to the field of optical communication. Specifically, it relates to a method for processing amplifier spontaneous emission noise and an optical fiber transmission network. Background Art

[0002] With the development of cloud computing, the demand for interconnected bandwidth has increased rapidly, along with the gradual improvement of the transmission bandwidth on optical fibers. The spectral range used in optical fiber communication has also expanded from the commonly used C band to the C+L band.

[0003] When the number of wavelength channels carried by an optical fiber is large, the transmission distance is long, and the spectral range used is wide, the operating conditions of the entire optical fiber transmission link are very different between the light load (a small number of wavelengths are turned on) and the heavy load (a large number of wavelengths are turned on) cases. For example, the total input power of erbium-doped fiber amplifiers (EDFAs) into the optical fiber, the nonlinear spectral slope, the single-channel transmission performance, etc. are quite different under different load conditions. So that the same gain and slope settings result in good transmission performance under light load conditions, but once under heavy load conditions, the original wavelength channels (or called wavelength channels) will no longer be within the normal operating point range. Thus, it is necessary to adjust the operating points of each network element on the line according to different link loads, and the adjustment and optimization of the entire system are relatively difficult. Summary of the Invention

[0004] Embodiments of this application provide a method for processing amplifier spontaneous emission noise and an optical fiber transmission network to at least solve the problem that the link needs to be adjusted from light load to heavy load, thereby affecting the system performance.

[0005] According to one aspect of this application, a method for processing amplifier spontaneous emission noise is provided, including: obtaining at least one wavelength channel MC created in a reconfigurable optical add-drop multiplexer ROADM; obtaining a first frequency range occupied by all wavelength channels in the at least one wavelength channel; removing the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; filling amplifier spontaneous emission ASE noise in the second frequency range.

[0006] According to another aspect of this application, a wavelength selection switch is further provided, including: software that, when executed, is used to implement the above method, where the software switches the wavelength ports of the wavelength selection switch to an ASE light source when the ASE noise filling is required.

[0007] According to another aspect of this application, a reconfigurable optical add-drop multiplexer is further provided, including: the above wavelength selection switch and the ASE light source, where the ASE light source is used to generate the ASE noise.

[0008] According to another aspect of the present application, an optical fiber transmission network is further provided, which includes a plurality of reconfigurable optical add-drop multiplexers. Among them, each of the reconfigurable optical add-drop multiplexers is connected by an optical multiplexing section. In each of the reconfigurable optical add-drop multiplexers, the ASE noise is processed according to the above method. The ASE noise filled in each reconfigurable optical add-drop multiplexer within its respective second frequency range terminates at the next reconfigurable optical add-drop multiplexer connected thereto.

[0009] According to another aspect of the present application, a readable storage medium is further provided, on which computer instructions are stored. When the computer instructions are executed by a processor, the above method steps are implemented.

[0010] According to another aspect of the present application, an amplifier spontaneous emission noise processing device is further provided, including: a first acquisition module for acquiring at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer ROADM; a second acquisition module for acquiring a first frequency range occupied by all wavelength channels in the at least one wavelength channel; a removal module for removing the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; a filling module for filling amplifier spontaneous emission ASE noise within the second frequency range.

[0011] In the embodiment of the present application, the following steps are adopted: acquiring at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer ROADM; acquiring a first frequency range occupied by all wavelength channels in the at least one wavelength channel; removing the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; filling amplifier spontaneous emission ASE noise within the second frequency range. By means of the present application, the problem that the link needs to be adjusted from light load to heavy load, thereby affecting the system performance, in an optical fiber network is solved. Furthermore, network fluctuations from light load to heavy load can be avoided by filling ASE noise, and the system stability is improved. Description of the Drawings

[0012] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0013] Figure 1 is a schematic diagram of ASE noise filling in a point-to-point link according to the related art;

[0014] Figure 2 is a schematic diagram of 100 GHz fixed spectrum filling according to the related art;

[0015] Figure 3It is a schematic diagram of continuous spectrum filling in related technologies;

[0016] Figure 4 It is a flowchart of a method for processing amplifier spontaneous emission noise according to an embodiment of the present application;

[0017] Figure 5 It is a schematic diagram of filling ASE noise in Mode 1 according to an embodiment of the present application;

[0018] Figure 6 It is a schematic diagram of a wavelength group in a MESH network according to related technologies;

[0019] Figure 7 It is a schematic diagram of filling ASE noise in Mode 2 according to an embodiment of the present application;

[0020] Figure 8 It is a schematic diagram of filling according to an interruption scenario of an embodiment of the present application. Detailed implementation manners

[0021] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0022] It should be noted that the steps shown in the flowchart of the drawings may be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than here.

[0023] In related technologies, for a multi-wavelength, wide-spectrum optical fiber transmission system, a method of using amplifier spontaneous emission (ASE for short) noise to fill wavelength channels can be adopted, so that the entire system works at full load on the first day. In one way, wavelength channels are created according to the frequencies to be filled, the created wavelength channels are used as ASE channels for transmitting ASE noise, and the ASE channels are replaced with wavelength channels when the wavelength channels need to be opened. In this way, the entire system works under the optimal full-load setting from the first day, simplifying the adjustment in the subsequent system operation stage. However, this processing method uses wavelength channels to transmit ASE noise, which will cause problems. The scheme of filling wavelength channels with ASE will be described below with reference to the drawings. Figure 1 It is a schematic diagram of ASE noise filling in a point-to-point link according to related technologies, Figure 1 Only a unidirectional network is shown, and the principle of a bidirectional network is the same and will not be described here again. The following takes Figure 1 the shown network for illustration.Figure 1 It involves technical terms such as ROADM, OCH, WSS, etc. First, these technical terms will be explained below.

[0024] A reconfigurable optical add-drop multiplexer (ROADM for short) is a device or equipment used in a dense wavelength division multiplexing (DWDM) system. Its function is to dynamically add or drop service wavelengths through remote reconfiguration. That is to say, in the middle of the line, the wavelengths for adding and dropping services can be arbitrarily assigned according to needs to achieve flexible scheduling of services. A wavelength selective switch (WSS for short) has the function of supporting any port wavelength for arbitrary up and down links, and each wavelength can be independently switched through the WSS.

[0025] In Figure 1 the signal transmitting end (referred to as the source site) is in ROADM1, the signal is transmitted to the WSS through the conversion module, the WSS is connected to the ASE light source through the branch port, and the signal receiving end (referred to as the sink site) is in ROADM6. In Figure 1 the signal transmission in Figure 1 needs to pass through ROADM1 to ROADM6. As Figure 1 shown, when the system opens the services from ROADM1 to ROADM6 on the first day. It is necessary to configure the WSS in the ROADM with a wavelength channel (Media Channel, MC for short) for transmitting ASE, and transmit the ASE noise generated by the ASE light source through this wavelength channel. In this case, configure the WSS in the ROADM to make the ASE noise pass through from the source site to the sink site along the service optical wavelength channel (Optical Channel, OCH for short). If the path of the service OCH is ROADM1 - ROADM2 - Intermediate Line Amplifier (ILA for short) - ROADM4 - ROADM5 - ROADM6, then the filling behavior of the ASE noise needs to create the filling spectrum through the MC to the branch port (trib) of the ASE noise in ROADM1, and all the corresponding filling spectra on the paths of ROADM2, ROADM4, and ROADM5 are passed through by creating the MC to ROADM6 drop (drop is to demultiplex the multiplexed optical signal). In this process, filling the ASE noise is achieved by the action of creating the MC on the WSS, and the wavelength channel used to transmit the ASE noise is transmitted from the source site to the sink site along with the service OCH.

[0026] When filling using the filling method of creating a new wavelength channel, it is necessary to delete the MC that has been filled with ASE noise and then create a new MC. This process of first deleting the MC and then creating it is rather cumbersome, with low processing efficiency and can affect the stability of the link. Additionally, with the continuous development of wavelength planning in optical fiber systems, the spectral width occupied by the channels configured in each optical multiplex section (OMS) will no longer be a fixed 50 GHz or 100 GHz width, but may be an uncertain width with a growth granularity of 12.5 GHz. For example, for a 96 G baud optical wavelength signal, it may occupy a spectral width of 112.5 GHz. In the above-mentioned scheme of first creating an MC and then filling it with ASE noise, it is filled with a fixed MC at the filling point, such as using 100 GHz as the fixed width of the filling wavelength. This filling method will leave frequency gaps when filling an MC that is not an integer multiple of 100 GHz, which may affect the stability of the system. Figure 2 is a schematic diagram of 100 GHz fixed spectrum filling in related technologies, as Figure 2 shown, MC1 and MC2 are wavelength channels that have been created for carrying services. Multiple MCs are created between MC1 and MC2, and each MC has a width of 100 GHz. These MCs are all filled with ASE noise. Now, it is necessary to create a new 125 GHz wavelength channel for carrying services. At this time, two MCs filled with ASE noise need to be deleted, and then a new MC (i.e., New MC) is created in the spectrum generated after deletion. In Figure 2 the processing method shown, when the filling is carried out according to a fixed width of 100 GHz, if a new wavelength channel is added for carrying services, two filled MCs need to be deleted first, and then a new MC is created. In this scheme, on the one hand, it is necessary to delete the MC filled with ASE noise and then create a new MC, increasing the complexity of creating an MC for services. On the other hand, gaps are left in the spectrum, which may affect the system stability.

[0027] As another filling method, an MC can be created for the spectrum between MC1 and MC2, and this MC is used to fill ASE noise. This method can be called the continuous spectrum filling method. Figure 3 is a schematic diagram of continuous spectrum filling in related technologies, as Figure 3As shown, an MC is created between MC1 and MC2. At this time, if a new MC (New MC) operating at 125 GHz for service transmission needs to be added, the MC filled with ASE noise needs to be deleted, and then the new 125-GHz MC is created. In addition, two MCs for filling ASE noise need to be created between MC1 and New MC and between New MC and MC2. Although the scheme of using continuous large-spectrum segments as filling does not cause spectral gaps, a large segment of the spectrum needs to be deleted during the filling process, resulting in significant fluctuations in the total power in the intermediate state. Moreover, the continuous-spectrum filling method also involves repeatedly deleting and creating MCs, and the process is relatively complex.

[0028] The problems existing in the above two filling methods are both caused by the need to first create an MC for ASE noise. To solve the problems existing in the two filling methods, in one embodiment, a method for processing amplifier spontaneous emission noise is provided. Figure 4 It is a flowchart of a method for processing amplifier spontaneous emission noise according to an embodiment of the present application. The steps involved in this method will be described below in conjunction with Figure 4 to explain the steps involved in this method.

[0029] Step S402: Obtain at least one wavelength-channel MC that has been created in a reconfigurable optical add-drop multiplexer (ROADM). It should be noted that the at least one wavelength channel is used for data transmission, and the data is service-based. Therefore, hereinafter, the wavelength channel used for data transmission will also be referred to as the wavelength channel for service transmission.

[0030] Step S404: Obtain the first frequency range occupied by all wavelength channels in the at least one wavelength channel.

[0031] Step S406: Subtract the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range.

[0032] Step S408: Fill the amplifier spontaneous emission (ASE) noise in the second frequency range.

[0033] It should be noted that the wavelength channels that have been created in the above steps are used for service transmission. For example, in Figure 1In the shown architecture, services are transmitted from ROADM1 to ROADM6. In this process, wavelength channels are created from ROADM1 through to ROADM6, that is, ROADM1, ROADM2, ROADM4, ROADM5, and ROADM6 are all configured with these wavelength channels. These wavelength channels used for service transmission are also called service optical channels (Optical Channel, abbreviated as OCH). Therefore, the service OCH runs through from ROADM1 to ROADM6. Multiplexing is used for transmitting optical signals in the optical fiber between ROADMs. Therefore, the transmission path between every two ROADMs is also called an optical multiplex section (Optical Multiplex Section, abbreviated as OMS), that is, the service OCH runs through multiple OMSs.

[0034] In the above steps, wavelength channels are not created for ASE noise. Instead, the frequency range without service transmission (i.e., the second frequency range) is obtained according to the frequency range of the wavelength channels that have been created for service transmission, and then the ASE noise is directly used to fill the second frequency range. This processing method does not require creating additional wavelength channels for ASE noise, so when creating new wavelength channels for service transmission, it is not necessary to delete the wavelength channels of ASE noise. Therefore, it will not cause large fluctuations and makes the link transmission more stable.

[0035] Since in the above steps, ASE noise is not transmitted through wavelength channels, there is no unified wavelength channel configured for ASE noise on each ROADM. When the filled ASE noise is transmitted from one end of the optical multiplex section (such as ROADM1 in Figure 1 ) to the other end of the optical multiplex section (such as ROADM2 in Figure 1 ), it will terminate (that is, the other end of the optical multiplex section will not pass on the ASE noise filled at one end of the optical multiplex section). At this time, the other end of the optical multiplex section will obtain the second frequency range according to the first frequency range occupied by the wavelength channels for services configured by itself, and fill the ASE noise according to the obtained second frequency range of itself. The same processing is performed at the other end of each optical multiplex section in this service OCH. In the following description, the scheme of filling ASE noise shown in Figure 4 is called Mode 1.

[0036] Figure 5 is the schematic diagram of filling ASE noise according to Mode 1 of the embodiment of the present application, as shown in Figure 5As shown in the figure, there is a ROADM at each end of the optical multiplexing section (OMS). For the sake of convenience in description, these two ROADMs are referred to as the left ROADM and the right ROADM, and the left ROADM and the right ROADM are connected by the optical multiplexing section OMS. The same optical channel (OCH) service is enabled on the left ROADM and the right ROADM. Therefore, both are configured with MC1 and MC2. The left ROADM obtains the frequency ranges of MC1 and MC2 (i.e., the first frequency range), then calculates the frequency range to be filled (i.e., the second frequency range) according to the frequency ranges of MC1 and MC2, and then fills the ASE noise within the second frequency range and sends it to the right ROADM. Since no wavelength channels are used to fill the ASE noise, the ASE noise sent by the left ROADM terminates at the right ROADM (for example, the right ROADM only receives and passes down the optical signals within the frequency ranges of MC1 and MC2). In Figure 5 if the right ROADM also needs to continue sending MC1 and MC2 downward, the right ROADM calculates the frequency range for filling the ASE noise according to the frequency ranges of MC1 and MC2, and sends it downward after filling the ASE noise.

[0037] As Figure 5 shown, the filling in Mode 1 occurs at the start of the OMS, automatically fills the spectrum without MC configured, and terminates at the end of the OMS, without being passed to the next OMS. This not only ensures full-load filling on the link but also prevents the filling failure of one OMS from affecting the next OMS. Since Figure 5 the filling between OMSs in Mode 1 is isolated from each other, it is applicable to various complex topological situations. Additionally, since there is no need to configure MC for each ROADM one by one, each ROADM can automatically configure the spectrum for filling the ASE noise according to the existing wavelength channels for services, thus complementing the spectrum faster.

[0038] Figure 5 The network environment shown in Figure 6 is relatively simple. Mode 1 can play a greater role when applied to a complex network environment. Figure 6 is a schematic diagram of wavelength groups in a MESH network according to the related technology. Figure 6 Compared with Figure 5 its network architecture is more complex. If the method of creating wavelength channels is used to fill the ASE noise in Figure 6 , it may bring unpredictable network instability. The following explains the use of the method of creating wavelength channels to fill the ASE noise in Figure 6 .

[0039] In the case of creating a wavelength channel for ASE noise, the filled spectrum of ASE can be understood as the ASE wavelength, and the filled wavelength is the spectrum complementary to the service wavelength. After filling, the routing of the ASE wavelength is the same as that of the service wavelength. Therefore, it is more suitable for long-distance point-to-point links. On such links, the spectra occupied by the service wavelengths everywhere are the same, so the filled ASE wavelengths are also the same. Whether filling at the time of system commissioning or during link failure, only the WSS of one ROADM site needs to be controlled for filling. This is because both ASE noise and service wavelengths have their respective wavelength channels, and the wavelengths in the wavelength channels are transmitted throughout the link. However, when the wavelengths occupied by services on the link are inconsistent on different OMSs, the filling of ASE noise will be very complex. At the termination of each OMS, the wavelengths to be filled need to be calculated. And when the network topology is a mesh network, a ROADM site has more than two dimensions. Therefore, the ROADM sites in the link may simultaneously serve as the sites through which ASE noise passes in two directions and the initiating sites for filling ASE noise in other directions. If the method of creating a wavelength channel for ASE noise is still adopted at this time, the filling calculation will be even more complex. The following will explain this with reference to the accompanying drawings.

[0040] Figure 6 is a schematic diagram of wavelength groups in a mesh network according to the related art, as Figure 6 shown, four groups of wavelength groups (OCH groups) are enabled in the network in the figure. Among them, the same wavelength channels are configured within each group of wavelength groups. ROADM4 and ROADM5 are the first wavelength group (OCH group1, abbreviated as OCHg1), ROADM1, ROADM2, and ROADM3 are the second wavelength group (OCH group2, abbreviated as OCHg2), ROADM3, ROADM5, and ROADM6 are the third wavelength group (OCH group3, abbreviated as OCHg3), and ROADM1, ROADM2, ILA / DGE, ROADM4, ROADM5, and ROADM6 are the fourth wavelength group (OCH group4, abbreviated as OCHg4). At this time, there may be many combinations of the whole network's ASE filling schemes. Taking the ROADM2 site in the figure as an example, assuming that the wavelength range of the full spectrum is O. Since ROADM1 and ROADM2 are the common sites of the second wavelength group and the fourth wavelength group, there are many ways to fill the ASE noise. Different paths can be used as the through paths for different filling methods, which will be explained separately below.

[0041] Assume that the wavelength channel for services in the second wavelength group is MC2, and the wavelength channel for services in the fourth wavelength group is MC4. MC1, MC3, and MC5 are wavelength channels filled with ASE noise. MC1, MC2, MC3, MC4, and MC5 are continuously distributed in the spectrum.

[0042] For example, the path ROADM1 - ROADM2 - ROADM3 in the second wavelength group can be used as a pass - through path. ROADM1 performs O - OCHg4 - OCHg2 filling (i.e., MC2 is the service wavelength, and MC1, MC3, MC4, and MC5 are filled with ASE noise). ROADM2 passes through all the filled wavelengths from ROADM1 to ROADM3. At the same time, for the dimension from ROADM2 to ROADM4, OCHg4 is filled (since MC4 is not the wavelength channel of the second wavelength group and is filled with ASE noise at this time, ROADM2 needs to fill MC4 with an OCHg4 optical signal, simply referred to as filling OCHg4). In the direction of ROADM2 - ROADM4, the wavelength of O - OCHg2 is filled as the ASE filling wave (since MC2 is not the wavelength channel of the fourth wavelength group, MC2 needs to be filled with ASE noise).

[0043] Another example, the path ROADM1 - ROADM2 - ROADM4 can be used as a pass - through path. ROADM1 performs O - OCHg4 - OCHg2 filling (i.e., MC4 is the service wavelength, and MC1, MC2, MC3, and MC5 are filled with ASE noise). ROADM2 passes through all the filled wavelengths from ROADM1 to ROADM4. At the same time, for the dimension from ROADM2 to ROADM4, OCHg2 is filled (since MC2 is not the wavelength channel of the fourth wavelength group and is filled with ASE noise at this time, ROADM2 needs to fill MC2 with an OCHg2 optical signal). In the direction of ROADM2 - ROADM3, the wavelength of OCHg4 is filled as the ASE filling wave (since MC4 is not the wavelength channel of the second wavelength group, MC4 needs to be filled with ASE noise).

[0044] Another example, all the filled wavelengths coming from the direction of ROADM1 are terminated at ROADM2. The ASE for the two directions of ROADM2 to ROADM3 and ROADM4 is refilled. Among them, for the direction from ROADM2 to ROAMD3, all except MC2 are filled with ASE noise, and for the direction from ROADM2 to ROAMD4, all except MC4 are filled with ASE noise.

[0045] As can be seen from the above three examples, when the ROADM can be used as a pass-through site and the starting site has different dimensions, there are a large number of ASE noise filling and distribution schemes. Moreover, the impact of the upstream link interruption on the downstream link varies with different filling wavelength distribution schemes. And it is very difficult to find an optimal distribution scheme. Therefore, this greatly increases the complexity of network management configuration.

[0046] If the steps shown in Figure 4 are adopted, filling the ASE noise in Figure 6 will become very simple and does not require network management configuration. Each WSS in each ROADM can make its own decision. In Figure 6 , the wavelength channels used by ROADM1 for services are MC2 and MC4. At this time, ROADM1 fills the remaining spectra except MC2 and MC4 with ASE noise. It should be noted that no wavelength channels are created at this time, but only the ASE noise is filled in these spectra. Since no wavelength channels are created for the ASE noise, ROADM2 only receives MC2 and MC4. Then, for the direction of ROADM4, ROADM2 transmits MC4 and fills the remaining spectra with ASE noise; for the direction of ROADM3, ROADM2 transmits MC2 and fills the remaining spectra with ASE noise. This processing method has no impact on the downstream link and does not require additional configuration of each ROADM by the network.

[0047] In Mode 1, not only can the frequency range of the wavelength channels be complemented with ASE noise faster, but also because no wavelength channels are created for the ASE noise in Mode 1, it enables faster processing when creating or deleting wavelength channels for services.

[0048] For example, delete a wavelength channel from the at least one wavelength channel; obtain the frequency range of the deleted wavelength channel; fill the ASE noise in the frequency range of the deleted wavelength channel as well. In this example, if a wavelength channel for services is deleted, the ASE noise can be directly filled according to the frequency range of the deleted wavelength channel, and there is no need to perform the process of creating new wavelength channels for filling the ASE noise.

[0049] Another example is that when a new wavelength channel needs to be added, directly create a new wavelength channel, where the frequency range of the new wavelength channel is within the second frequency range; obtain the frequency range of the new wavelength channel; stop filling the ASE noise in the frequency range of the new wavelength channel. In this example, there is no need to delete the wavelength channels created for filling the ASE noise either. Instead, directly obtain the frequency range of the new wavelength channel, and then stop filling the ASE noise in the frequency range of the new wavelength channel.

[0050] In the above Mode 1, since there is no need to create a wavelength channel for filling ASE noise, it can be implemented by the software configured by the WSS itself. This software can control the WSS to switch the optical path to the ASE light source within a predetermined frequency range. Through the above two examples, the filling method is continuous filling with a complementary spectral shape to the MC within the spectral range, which is not achieved by creating an MC, but by the software of the WSS itself. After the WSS creates an MC, the ASE noise filled within the MC spectral range is automatically cancelled. After the WSS deletes the MC, if Mode 1 is enabled, the ASE noise within the MC spectral range is automatically restored for filling.

[0051] In the above embodiment, no wavelength channel is created for filling ASE noise. The benefits brought by this are not only more convenient when creating or deleting wavelength channels for services, but also when a line failure occurs. For example, when the upstream transmission fiber in the network is interrupted, causing a change in the wavelength load of the downstream link, ASE noise filling can be adopted to make the downstream link return to the full-load working condition, so that the transmission performance of the downstream wavelength services can also be quickly restored. In the following description, the filling mode after a line failure is referred to as Filling Mode 2.

[0052] Still take Figure 1 as an example to illustrate the handling of failures in the case of creating a wavelength channel for ASE noise. 2 In Figure 1 a fiber optic system, a link failure occurs, where the failure location is between ROADM1 and ROADM2, as shown at the X position in Figure 1 . Assume Figure 1 that there are two wavelength channels for services transmitted in

[0053] Figure 1 , namely MC1 and MC2. If MC1 fails and it is desired to keep the downstream link of ROADM2 working properly and maintain the downstream link in a normal state, that is, at this time, the MC1 of the WSS in the downstream ROADM4, ROADM5, and ROADM6 is expected to still maintain the normal channel settings. In this case, when the link at X is restored and the wavelength signal transmitted upstream is restored, the working conditions of the downstream nodes remain unchanged, so the services can be quickly restored. Figure 6 The network environment shown in Figure 6 is relatively simple. If a failure occurs in Figure 6As shown in the X position in the figure, to ensure full load on the downstream link, at this time, ROADM2 becomes a full-spectrum O filled with ASE wavelengths in both the directions of ROADM3 and ROADM4. At this time, all the MCs on the trib ports coming from ROADM1 need to be created on the WSS as filling channels. This includes both the service wavelength MCs and the MCs of the ASE filling channels. Since the WSS is configured serially for each MC, this speed will be relatively slow.

[0054] To solve Figure 1 and Figure 6 the problems existing in the figure, in Mode 2, for the wavelength channels used for service transmission that have failed, ASE noise can be used to fill the failed wavelength channels. The wavelength channels filled with ASE noise can penetrate the OMS. Therefore, the ROADM in the downstream link still operates in a normal state, and the downstream link can be quickly restored after the failed wavelength channels are restored. That is, in Mode 2, the following steps can be included: obtaining the failed wavelength channels in the at least one wavelength channel; obtaining the power mode and / or attenuation mode used by the failed wavelength channels before the failure occurs; filling the ASE noise in the frequency range of the failed wavelength channels according to the power mode and / or attenuation mode. By using ASE noise in Mode 2 to completely simulate the wavelength channels before the failure, the downstream link will not be affected and will always be in a normal operating mode.

[0055] Figure 7 is the schematic diagram of filling ASE noise in Mode 2 according to an embodiment of the present application. As Figure 7 shown, there is a ROADM at each end of the optical multiplexing section OMS. For the convenience of description, these two ROADMs are called the left ROADM and the right ROADM. The left ROADM and the right ROADM are connected through the optical multiplexing section OMS. The same service OCH is opened on the left ROADM and the right ROADM. Therefore, both are configured with MC1 and MC2. The left ROADM obtains the frequency ranges of MC1 and MC2 (i.e., the first frequency range), then calculates the frequency range to be filled (i.e., the second frequency range) according to the frequency ranges of MC1 and MC2, and then fills the ASE noise in the second frequency range and sends it to the right ROADM. Since no wavelength channels are used to fill the ASE noise, the ASE noise sent by the left ROADM terminates at the right ROADM. At this time, the left ROADM fails and does not receive MC1 and MC2. The left ROADM fills the ASE noise according to the power mode or attenuation mode of the original wavelengths of MC1 and MC2 respectively. The right ROADM receives the ASE noise filled according to the original wavelengths in MC1 and MC2 and continues to transmit downward.

[0056] In another alternative embodiment, to ensure that the downstream link is not affected, the port of the failed wavelength channel can also be used. In this alternative embodiment, filling the ASE noise in the frequency range of the failed wavelength channel according to the power mode and / or attenuation mode may include: obtaining the port used by the failed wavelength channel before the failure occurs; keeping the port unchanged, and filling the ASE noise in the frequency range of the failed wavelength channel through the port according to the power mode and / or attenuation mode. Through this alternative method, the original port of the failed wavelength channel is used, so that timely switching can be performed after the failed wavelength channel is restored. At the same time, since the original port is used, after the failed wavelength channel recovers from the failure, it is only necessary to directly stop filling the ASE noise in the failed frequency range, and the restored optical signal can be transmitted through the original port.

[0057] To enable the ROADM to distinguish which wavelength channel has failed, as an alternative embodiment, an identifier can be added to the failed wavelength channel, where the identifier is used to indicate that the wavelength channel has failed and the ASE noise needs to be filled; after the failed wavelength channel recovers from the failure, the identifier on the failed wavelength channel is cleared.

[0058] Through the above Mode 2, the MC list to be filled can be sent by the network management. The WSS does not change the port settings of the MCs, but only adds an identifier to the MCs that need to be filled. At this time, when querying the MCs of the device, the ports of the MCs are still the service wavelength ports. The identified MCs switch the add direction (the direction of adding services in the optical fiber) to the ASE source through the WSS's own software and fill it according to the power mode or attenuation mode of the original wavelength. The identified MCs only fill the add direction from the branch port to the common port, and the drop direction (the direction of extracting services from the optical fiber) remains unchanged.

[0059] The following combines Figure 8 to illustrate the comprehensive application of Mode 1 and Mode 2. Figure 8 is a schematic diagram of filling according to the interruption scenario of the embodiment of the present application, as Figure 8As shown, it involves four ROADMs and one ILA. For the sake of description, these four ROADMs are successively called the first ROADM, the second ROADM, the third ROADM, and the fourth ROADM from left to right. When filling using mode one, the first ROADM transmits MC2 (i.e., OCH2) to the second ROADM. Therefore, the first ROADM fills other frequency ranges except the MC2 frequency range with ASE noise. The second ROADM terminates the ASE noise transmitted by the first ROADM, receives MC2, and adds MC1 (i.e., OCH1) at the second ROADM. At this time, the second ROADM fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the third ROADM; the third ROADM receives MC1 and MC2, and fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the fourth ROADM.

[0060] At this time, in case of a failure, the second ROADM does not receive MC2 from the first ROADM. However, since the wavelength channel of MC2 is still there, the second ROADM fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the third ROADM; the third ROADM receives MC1 and MC2, but since there was an interruption in MC2 before, there is no power here. The third ROADM fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the fourth ROADM.

[0061] The second ROAMD fills MC2 with ASE noise using the power mode or attenuation mode corresponding to the original wavelength of MC2 according to mode two in the above embodiment and transmits it to the third ROADM; the third ROADM receives MC1 and MC2 (MC2 filled with ASE noise), and fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the fourth ROADM.

[0062] Subsequently, when the failure is recovered, the first ROADM transmits MC2 to the second ROADM. Therefore, the first ROADM fills other frequency ranges except the MC2 frequency range with ASE noise. The second ROADM terminates the ASE noise transmitted by the first ROADM, receives MC2, and adds MC1 at the second ROADM. At this time, the second ROADM fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the third ROADM; the third ROADM receives MC1 and MC2, and fills other frequency ranges except the MC1 and MC2 frequency ranges with ASE noise and transmits it to the fourth ROADM.

[0063] Figure 8 integrates Figure 5 and Figure 7 the Mode 1 and Mode 2 shown respectively in Figure 5 As shown, Mode 1 filling occurs at the start of the OMS, automatically filling the spectrum without configured MC, and ending at the end of the OMS. It will not be passed to the next OMS. This not only ensures full-load filling on the link but also prevents the filling failure of one OMS from affecting the next OMS. The filling between OMSs is isolated from each other, suitable for various complex topological situations. Since there is no need to configure each MC one by one, the complementary spectrum can be automatically configured faster.

[0064] As Figure 7 shown, Mode 2 filling fills the service wavelength in case of a fault, and the filled wavelength has the same route as the original wavelength. It can pass through the OMS and maintain the MC of the original wavelength unchanged on each ROADM. When a fault occurs and recovers, only the first WSS downstream of the fault point needs to fill the affected service wavelength channels, without filling the entire spectrum, and the WSSs in other parts of the network maintain the original MC configuration unchanged, with relatively efficient adjustment.

[0065] Figure 8 shows the ASE filling of the entire system under the cooperation of the two modes, as well as the filling situation during the occurrence and recovery of faults: When the system is working normally, Mode 1 fills inside each OMS one by one, and ASE does not cross OMSs, only the service OCH passes through the OMS. When a line interruption fault occurs, the branch port of the WSS of the second ROADM detects loss and performs Mode 2 filling on the OCH of this branch port, while the Mode 1 filling of each OMS remains unchanged. At this time, the interrupted OCH continues to be transmitted along the original route after Mode 2 filling. The power of the downstream node changes little. When the fault is repaired, the wavelength filled by Mode 2 resumes to the signal power.

[0066] Through the cooperation of the above Mode 1 and Mode 2, the filling inside the OMS is automatically completed by the ROADM, and the upper-layer network management does not need to care about the filling details. The filling passing through the OMS is consistent with the service wavelength. The network management only needs to manage the service wavelength topology. When a fault occurs, the filling scheme is clear, and there are no multiple filling possibilities. Moreover, there is no problem of spectrum mismatch in this scheme. In addition, when creating a new MC on the WSS, the spectrum corresponding to Mode 1 will be automatically unfilled, and no additional spectrum gaps will be caused during and after the filling process, no large power changes will occur, and the link is more stable.

[0067] The above-described embodiments can be implemented in a wavelength selective switch. That is, in one embodiment, there is also provided a wavelength selective switch, including: software, which is used to implement the above method when executed, wherein the software switches to an ASE light source when the ASE noise filling is required. In this alternative embodiment, there is also provided a reconfigurable optical add-drop multiplexer, including the wavelength selective switch and the ASE light source, wherein the ASE light source is used to generate the ASE noise.

[0068] In this embodiment, there is provided an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the method in the above embodiments.

[0069] The above program can run in the processor or can also be stored in the memory (or referred to as a computer-readable medium). The computer-readable medium includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The 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, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0070] These computer programs can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate computer-implemented processing. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 The steps corresponding to different steps can be implemented by different modules.

[0071] In this embodiment, such a device is provided. The device is called an amplifier spontaneous emission noise processing device, including: a first acquisition module for acquiring at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer ROADM; a second acquisition module for acquiring a first frequency range occupied by all wavelength channels in the at least one wavelength channel; a removal module for removing the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; and a filling module for filling amplifier spontaneous emission ASE noise in the second frequency range.

[0072] The system or device is used to implement the functions of the method in the above embodiment. Each module in the system or device corresponds to each step in the method. Those that have been described in the method will not be elaborated here.

[0073] Optionally, the filling module is further configured to, after deleting a wavelength channel from the at least one wavelength channel, acquire the frequency range of the deleted wavelength channel, and also fill the ASE noise in the frequency range of the deleted wavelength channel.

[0074] Optionally, the filling module is further configured to, after creating a new wavelength channel, where the frequency range of the new wavelength channel is within the second frequency range, acquire the frequency range of the new wavelength channel, and stop filling the ASE noise in the frequency range of the new wavelength channel.

[0075] Optionally, the filling module is further configured to, after acquiring a wavelength channel that has failed in the at least one wavelength channel, acquire the power mode and / or attenuation mode used by the failed wavelength channel before the failure occurs, and fill the ASE noise in the frequency range of the failed wavelength channel according to the power mode and / or attenuation mode.

[0076] Optionally, the filling module is configured to acquire the port used by the failed wavelength channel before the failure occurs, keep the port unchanged, and fill the ASE noise in the frequency range of the failed wavelength channel through the port according to the power mode and / or attenuation mode.

[0077] Optionally, the filling module is further configured to stop filling the ASE noise in the frequency range of the failed wavelength channel after the failed wavelength channel recovers from the failure.

[0078] Further, the device may further include: an identification module, configured to add an identification to the wavelength channel where the fault occurs, where the identification is used to indicate that the wavelength channel has a fault and needs to perform the filling of the ASE noise; after the wavelength channel where the fault occurs recovers from the fault, clear the identification on the wavelength channel where the fault occurs.

[0079] Through the above implementation manner, the system ASE filling is divided into two modes, namely, the internal filling of the OMS and the wavelength filling across the OMS (i.e., Mode 1 and Mode 2). Among them, Mode 1 is realized by the automatic filling of the OMS device software, does not expose the MC configuration to the upper layer, simplifies the network management control, and the filling is more efficient. Mode 2 fills the service wavelength when a line fault occurs. The filling method is clear, there is no need to change the parameter configuration of the MC, and both the filling and the recovery are more efficient. With the cooperation of the two modes, in the case of a link fault, the ASE of Mode 1 will not affect across the OMS, and there is no need to add or delete the filled spectrum when creating a new wavelength, so there will be no large power fluctuations downstream, and the transmission link is more stable.

[0080] The above are only the embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for processing amplifier spontaneous emission noise, comprising: Obtain at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer (ROADM); Obtain the first frequency range occupied by all wavelength channels in the at least one wavelength channel; Subtract the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; Fill the amplified spontaneous emission (ASE) noise within the second frequency range.

2. The method according to claim 1, wherein, Further includes: Delete a wavelength channel from the at least one wavelength channel; Obtain the frequency range of the deleted wavelength channel; Similarly fill the ASE noise within the frequency range of the deleted wavelength channel.

3. The method according to claim 1, wherein, Further includes: Create a new wavelength channel, where the frequency range of the new wavelength channel is within the second frequency range; Obtain the frequency range of the new wavelength channel; Stop filling the ASE noise within the frequency range of the new wavelength channel.

4. The method according to any one of claims 1 to 3, wherein, Further includes: Obtain the wavelength channel that has failed among the at least one wavelength channel; Obtain the power mode and / or attenuation mode used by the failed wavelength channel before the failure occurred; Fill the ASE noise within the frequency range of the failed wavelength channel according to the power mode and / or attenuation mode.

5. The method according to claim 4, wherein, Filling the ASE noise within the frequency range of the failed wavelength channel according to the power mode and / or attenuation mode includes: Obtain the port used by the failed wavelength channel before the failure occurred; Keep the port unchanged, and fill the ASE noise within the frequency range of the failed wavelength channel through the port according to the power mode and / or attenuation mode.

6. The method according to claim 4, wherein, Further includes: After the failed wavelength channel recovers from the failure, stop filling the ASE noise within the frequency range of the failure.

7. The method according to claim 6, wherein, Further includes: Add an identifier to the failed wavelength channel, where the identifier is used to indicate that the wavelength channel has failed and requires filling of the ASE noise; After the failed wavelength channel recovers from the failure, clear the identifier on the failed wavelength channel.

8. A wavelength selective switch, the wavelength selective switch being software controlled, the wavelength selective switch being disposed in a reconfigurable optical add-drop multiplexer, wherein, When the software is executed, it is used to implement the method according to any one of claims 1 to 7, where the software switches the wavelength port of the wavelength selection switch to the ASE light source when the ASE noise filling is required.

9. A reconfigurable optical add-drop multiplexer, comprising: The wavelength selection switch and the ASE light source according to claim 8, where the ASE light source is used to generate the ASE noise.

10. An optical fiber transmission network, comprising a plurality of reconfigurable optical add-drop multiplexers, wherein, Each of the reconfigurable optical add-drop multiplexers is connected through an optical multiplexing section. In each of the reconfigurable optical add-drop multiplexers, the ASE noise is processed according to the method according to any one of claims 1 to 7. The ASE noise filled within the respective second frequency range of each reconfigurable optical add-drop multiplexer terminates at the next reconfigurable optical add-drop multiplexer connected to it.

11. A readable storage medium, having computer instructions stored thereon, wherein, When the computer instruction is executed by a processor, it implements the method steps according to any one of claims 1 to 7.

12. An amplifier spontaneous emission noise processing device, comprising: A first acquisition module, configured to obtain at least one wavelength channel MC that has been created in a reconfigurable optical add-drop multiplexer (ROADM); A second acquisition module, configured to acquire a first frequency range occupied by all wavelength channels in the at least one wavelength channel; A removal module, configured to remove the first frequency range from the frequency range supported by the ROADM to obtain a second frequency range; A filling module, configured to fill amplified spontaneous emission (ASE) noise in the second frequency range; 13. The device according to claim 12, wherein, The filling module is further configured to, after deleting a wavelength channel from the at least one wavelength channel, acquire the frequency range of the deleted wavelength channel, and also fill the ASE noise in the frequency range of the deleted wavelength channel; The filling module is further configured to, after creating a new wavelength channel, where the frequency range of the new wavelength channel is within the second frequency range, acquire the frequency range of the new wavelength channel, and stop filling the ASE noise in the frequency range of the new wavelength channel; The filling module is further configured to, after acquiring a wavelength channel that fails in the at least one wavelength channel, acquire the power mode and / or attenuation mode used by the failed wavelength channel before the failure occurs, and fill the ASE noise in the frequency range of the failed wavelength channel according to the power mode and / or attenuation mode; The filling module is configured to acquire the port used by the failed wavelength channel before the failure occurs, keep the port unchanged, and fill the ASE noise in the frequency range of the failed wavelength channel through the port according to the power mode and / or attenuation mode; The filling module is further configured to, after the failed wavelength channel recovers from the failure, stop filling the ASE noise in the frequency range of the failure; It further includes: an identification module, configured to add an identification to the failed wavelength channel, where the identification is used to indicate that the wavelength channel has failed and needs to have the ASE noise filled, and after the failed wavelength channel recovers from the failure, clear the identification on the failed wavelength channel.

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