Method and system for fast locating fiber degradation span in multi-span optical transmission system

Abstract

This application relates to the field of wireless communication technology and provides a method and system for rapid location of fiber optic deterioration in multi-segment optical transmission systems. The method involves pre-storing the received optical power reference values ​​of the short-wavelength out-of-band (SWBOT) and long-wavelength out-of-band (WBOT) optical monitoring channels at the receiving side of each fiber segment under normal, non-deterioration conditions. The wavelength of the SFBOT channel is shorter than the wavelength range of the short-wavelength service band, while the wavelength of the WBOT channel is longer than the wavelength range of the long-wavelength service band. The receiving side of each fiber segment collects the received optical power values ​​of the SFBOT and WBOT channels in real time. The power change between the current received optical power of each monitoring channel and the corresponding reference value is calculated. Based on the power change trends of the two monitoring channels, a local determination is made, and gain compensation is triggered on the receiving-side optical amplifier of the segment determined to be deteriorated.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a method and system for rapid location of fiber optic deterioration in multi-segment optical transmission systems. Background Technology

[0002] With the continuous increase in the capacity of optical transmission systems and the widespread application of multi-band transmission architecture, the number of service wavelengths carried by the links and the total capacity have increased significantly, which has placed higher demands on the rapid detection and location of optical fiber link anomalies.

[0003] In multi-span optical transmission systems, fiber degradation in a single span leads to a synchronous decrease in received optical power across all downstream spans. If multiple downstream optical amplifiers simultaneously perform gain boosting, overcompensation, amplifier saturation, and power oscillations can easily occur. Existing fiber degradation segment location schemes rely on adjacent sites transmitting transmit power information through optical monitoring channels and calculating segment loss collaboratively between sites to locate the degradation. This scheme is limited by communication latency in the optical monitoring channel, protocol processing latency, and site control logic latency, resulting in a significant bottleneck in segment location speed and failing to meet the rapid recovery requirements of multi-band, high-capacity transmission systems. Summary of the Invention

[0004] This application provides a method and system for rapid location of fiber optic deterioration in multi-segment optical transmission systems. It aims to address the challenges posed by the increasing capacity of optical transmission systems, the widespread application of multi-band transmission architectures, and the significant increase in the number of service wavelengths and total capacity carried by the links, which in turn raises the requirements for rapid detection and location of fiber optic link anomalies.

[0005] In a first aspect, embodiments of this application provide a method for rapid location of fiber degradation segments in a multi-segment optical transmission system, the method comprising: Pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The receiving side of each optical fiber segment collects the received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel in real time; and calculates the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. Local determination is made based on the power change trends of the two optical monitoring channels. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. Furthermore, if the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be a downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. Gain compensation is triggered on the receiving-side optical amplifier of the segment determined to be a fiber degradation segment.

[0006] In some embodiments, the pre-storing of the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber span under normal conditions without degradation includes collecting the received optical power values ​​of the two optical monitoring channels under different service channel loading states and different ambient temperature ranges when each optical fiber span is free from degradation, generating multiple sets of corresponding matching reference values ​​and storing them in categories.

[0007] In some embodiments, the receiving side of each optical fiber segment collects the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time, including collecting the original received optical power values ​​of the two optical monitoring channels according to a preset sampling period, performing short-time noise reduction processing on the original values, and outputting the processed received optical power values.

[0008] In some embodiments, calculating the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value includes selecting a reference value that matches the current service channel loading status and the current ambient temperature, and calculating the difference between the current received optical power of the two optical monitoring channels and the matching reference value as the power change of the corresponding channel.

[0009] In some embodiments, triggering gain compensation for the receiving-side optical amplifier in a segment determined to be a fiber degradation segment includes sending a gain adjustment command only to the optical amplifier in the current segment receiving side, controlling the optical amplifier to increase the corresponding gain to compensate for the additional loss generated in the current segment, and not sending a gain increase command to the optical amplifier in the downstream segment.

[0010] In some embodiments, the method further includes stopping the local fast judgment process and switching to a cross-segment loss calculation process based on the transmission power of the upstream site for degradation location verification when the power change trend of the two optical monitoring channels does not meet the preset judgment mode.

[0011] In some embodiments, the method further includes, after completing the current segment degradation determination, reading the power change determination result of the downstream adjacent segment, and when the downstream adjacent segment is determined to be a downstream affected segment of degradation point, increasing the confidence level of the current segment degradation determination result.

[0012] Secondly, this application provides a rapid location system for fiber degradation in multi-segment optical transmission systems, the system comprising: The normal storage unit is used to pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The numerical monitoring unit is used to collect the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time at each optical fiber segment receiving side; and to calculate the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. The action triggering unit is used to make local judgments based on the power change trends of the two optical monitoring channels. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. When the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be the downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. The gain compensation action is triggered on the receiving-side optical amplifier of the segment determined to be a fiber degradation segment.

[0013] The method provided in this application can determine the degradation of a segment by relying solely on the power data of two out-of-band optical monitoring channels monitored locally on each segment receiving side, without waiting for the power information transmission and protocol interaction from the upstream site, thus significantly shortening the degradation identification and response time.

[0014] By differentiating the power change trends of the two optical monitoring channels, the actual degraded segment and the downstream affected segment are accurately distinguished. Gain compensation for the optical amplifier is triggered only for the degraded single segment, preventing oversaturation and power oscillation issues caused by synchronous gain increases in multi-stage amplifiers. Existing out-of-band optical monitoring channels and received power monitoring modules in multi-band optical transmission systems can be directly reused without adding additional link detection hardware, making it suitable for upgrades and modifications to existing systems. Utilizing the stimulated Raman scattering power transfer characteristics in broadband fiber transmission as a criterion, it fully adapts to the link monitoring requirements of multi-band high-capacity optical transmission systems.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart illustrating the steps of a method for rapid location of fiber degradation in a multi-segment optical transmission system according to an embodiment of this application; Figure 2 This is a schematic diagram of a multi-segment C+L optical transmission system structure provided in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the OSC power variation trend of the degraded span and the downstream span according to an embodiment of this application; Figure 4 This is a flowchart of a method for rapid location of fiber degradation in a multi-segment optical transmission system according to an embodiment of this application; Figure 5 This is a schematic block diagram of a rapid fiber degradation segment location system for a multi-segment optical transmission system provided in one embodiment of this application; Figure 6 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0021] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0022] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] With the continuous increase in the capacity of optical transmission systems and the widespread application of multi-band transmission architecture, the number of service wavelengths carried by the links and the total capacity have increased significantly, which has placed higher demands on the rapid detection and location of optical fiber link anomalies.

[0025] In multi-span optical transmission systems, fiber degradation in a single span leads to a synchronous decrease in received optical power across all downstream spans. If multiple downstream optical amplifiers simultaneously perform gain boosting, overcompensation, amplifier saturation, and power oscillations can easily occur. Existing fiber degradation segment location schemes rely on adjacent sites transmitting transmit power information through optical monitoring channels and calculating segment loss collaboratively between sites to locate the degradation. This scheme is limited by communication latency in the optical monitoring channel, protocol processing latency, and site control logic latency, resulting in a significant bottleneck in segment location speed and failing to meet the rapid recovery requirements of multi-band, high-capacity transmission systems.

[0026] Please refer to Figure 1 This application provides a method for rapid location of fiber degradation segments in a multi-segment optical transmission system. Based on the wavelength energy transfer physical characteristics of stimulated Raman scattering in the optical fiber transmission link, it uses two out-of-band optical monitoring channels located outside the service band to complete local independent fault determination. This eliminates the need for cross-site transmission of interactive monitoring data, significantly reducing link fault location latency. At the same time, it accurately distinguishes between truly degraded segments and downstream segments affected by power disturbances, avoiding system oscillations, device saturation, and other faults caused by the synchronous gain increase of multi-stage optical amplifiers.

[0027] This method can be executed by a computer device with the capabilities of data acquisition, numerical operation, logical judgment, and device control. The computer device can be independently deployed on a single server or a distributed server cluster, or can be integrally deployed on hardware carriers with local computing power such as handheld operation and maintenance terminals, on-site operation and maintenance laptops, intelligent wearable operation and maintenance devices, and built-in control units of inspection robots that are supporting the optical transmission site. All optical power monitoring data, link reference parameters, and threshold configuration parameters collected, calculated, and stored during the execution of this method are extracted and locally stored on the premise that the network operation and maintenance user has completed written authorization and complies with the data security management specifications of the communication industry. User service-bearing data is not collected, parsed, or stored throughout the process, and there is no risk of user privacy leakage.

[0028] The basic transmission system architecture adapted by this invention is referenced in the appendix Figure 2 , the system includes multiple cascaded fiber spans, and optical amplifier sites are deployed at both ends of each fiber span. A short-wave out-of-band optical monitoring channel is configured outside the C-band service wavelength range, and a long-wave out-of-band optical monitoring channel is configured outside the L-band service wavelength range. A dual-channel optical power monitoring hardware module, a local logical judgment module, and an optical amplifier gain control module are deployed at the receiving side of each span. All monitoring, calculation, determination, and control processes are completed locally at a single site, and there is no need to transmit monitoring interaction messages between sites.

[0029] The provided method for quickly locating fiber deterioration spans in a multi-span optical transmission system includes steps S101 to S103. Details are as follows: Step S101. Pre-store the received optical power reference values of the short-wave out-of-band optical monitoring channel and the long-wave out-of-band optical monitoring channel at the receiving side of the span under the normal state of no fiber deterioration for each fiber span, the wavelength range of the short-wave out-of-band optical monitoring channel shorter than the short wavelength service band, and the wavelength range of the long-wave out-of-band optical monitoring channel longer than the long wavelength service band.

[0030] Specifically, establish a standard power comparison data set when the fiber link has no additional loss and is in a stable operating state, distinguish the inherent offset of the dual-channel optical power under different service loads and environmental temperatures, eliminate the interference of system normal operating conditions fluctuations on the fault determination result, and provide an accurate reference standard for subsequent real-time power change calculation.

[0031] There are no deterioration faults such as loose connectors, bent fibers, pipe extrusion, and construction damage in all fiber spans of the whole line; the C-band and L-band service wavelength loading states are stable, there are no large-scale service up / downlines and ROADM wavelength switching operations; the pump power and gain control parameters of the optical amplifier remain constant for a long time; the environmental temperature of the site computer room is continuously stable without large fluctuations, and after the system has continuously and stably operated for a preset duration, the reference acquisition operation is carried out.

[0032] The system enters the initialization baseline acquisition mode, traverses all fiber optic segments within the transmission network, and enables the dual-channel optical power continuous acquisition function for each segment. For each fiber optic segment, dual-channel steady-state received optical power values ​​were collected under multiple operating conditions: the first group collected power data under the standard ambient temperature range of the equipment room with a fixed number of service channels; the second group collected power data under the high temperature range of the equipment room with full service channel loading; and the third group collected power data under the low temperature range of the equipment room with sparse service channel loading. For each set of operating conditions, the raw power data collected continuously is averaged and smoothed to remove instantaneous power jump noise, and the standard reference values ​​for the short-wave band external optical monitoring channel and the long-wave band external optical monitoring channel corresponding to that operating condition are generated. The four sets of parameters, namely “service loading quantity, ambient temperature range, shortwave reference value, and longwave reference value”, are bound together into a set of reference data and stored locally in the storage units of each cross-segment receiver using a classified index, forming a multi-dimensional reference data table. During daily operation, if there is a large-scale scheduling of service wavelengths, a long-term deviation in the computer room temperature, or a modification of the optical amplifier control parameters, the system will automatically re-collect steady-state power data under the corresponding operating conditions and synchronously update the benchmark values ​​for matching operating conditions to ensure that the benchmark data is consistent with the real-time operating conditions.

[0033] Among them, the shortwave band out-of-band optical monitoring channel has a wavelength shorter than all C-band service wavelengths. At this position, the wavelength will continuously transfer energy to a longer wavelength channel through stimulated Raman scattering during optical fiber transmission, and has a clear power change distinguishing feature. The long-wavelength external optical monitoring channel has a wavelength longer than all L-band service wavelengths. This wavelength continuously receives energy transferred from the shortwave channel, forming a differentiated power change trend with the shortwave channel. The two can be used together to distinguish between the degradation of this segment and the power disturbance of the downstream segment. The reference data is stored locally in independent storage units on the receiving side of each segment. The reference data is only read and used locally and does not need to be synchronized to upstream or downstream adjacent sites, so there is no cross-site data transmission delay.

[0034] By using multi-condition, multi-dimensional benchmark data, inherent power offsets caused by environmental factors and service loads can be distinguished, avoiding misjudging normal system fluctuations as fiber optic degradation faults. The benchmark data is stored locally and independently, and subsequent steps can directly retrieve matching parameters without cross-site interaction, providing a data foundation for rapid local determination.

[0035] Step S102. The receiving side of each optical fiber segment collects the received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel at the current moment in real time; calculates the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value.

[0036] Specifically, the system continuously acquires raw optical power data in real time through dual channels, eliminates instantaneous noise interference through filtering, retrieves a benchmark value that matches the current operating conditions, quantifies the deviation of real-time power from the steady-state benchmark, and outputs standardized quantitative change parameters as the core input indicators for local fault determination.

[0037] Step S101 has completed the storage of the multi-dimensional reference data table for the entire segment; the hardware of the dual-channel optical power monitoring module on the receiving side of each segment is online normally, with no device failures or abnormal optical channel loss; the system has been configured with fixed sampling period, filtering parameters, and power threshold parameters and has completed local loading.

[0038] Each fiber optic segment receiver monitoring module synchronously collects the real-time raw received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel according to the system's preset fixed sampling period; The raw power values ​​obtained from continuous multi-sampling cycles are subjected to short-time moving average filtering to filter out power jumps caused by instantaneous micro-bending of optical fibers and instantaneous noise of monitoring devices, and output a stable real-time power value after filtering. Real-time reading of the current cross-segment real-time service channel loading quantity and real-time ambient temperature of the computer room; and accurate matching of shortwave and longwave reference values ​​that perfectly correspond to the working conditions in the local multi-dimensional reference data table. Perform the difference calculation separately, subtract the shortwave reference value of the matching condition from the real-time shortwave power after filtering to obtain the change in shortwave channel power; subtract the longwave reference value of the matching condition from the real-time longwave power after filtering to obtain the change in longwave channel power. The two sets of power change values ​​are locally cached and synchronously transmitted to the local logic decision module as quantitative input parameters for trend determination in step S103.

[0039] The sampling period and the duration of the moving average filter window can be flexibly configured according to the length of the transmission link segment, the type of optical fiber, and the accuracy of the monitoring device. For long-distance segments, the filter window can be extended to suppress noise, while for short-distance metropolitan area segments, the window can be shortened to ensure response speed. The power change is calculated locally on the receiving side of a single span. The calculation process does not require requesting power monitoring messages from upstream sites, and there is no delay loss caused by OSC channel message transmission and protocol parsing.

[0040] By filtering out transient noise, the stability of power values ​​is improved; the calculation of the operating condition matching benchmark difference can accurately isolate the inherent power deviation caused by temperature and business load, and the quantified value can intuitively reflect the power deviation caused by the additional loss of the link, providing a reliable quantitative basis for trend logic judgment.

[0041] Step S103. Based on the power change trends of the two optical monitoring channels, a local determination is made. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. When the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be the downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. The gain compensation action is triggered on the receiving-side optical amplifier of the segment determined to be a fiber degradation segment.

[0042] Specifically, based on the positive and negative values ​​and amplitude differences of the power changes in the dual channels, and combined with the physical laws of stimulated Raman scattering in optical fibers, three types of link states are independently distinguished at a single site: fiber degradation in this segment, power disturbance in the downstream segment, and no link abnormality. Only the optical amplifier gain compensation is triggered for the truly degraded segment, and the synchronous gain increase of the downstream disturbed segment is prohibited, thus avoiding system power oscillation and device saturation problems caused by synchronous compensation of multi-stage amplifiers.

[0043] Step S102 has output the current power change of the two groups of shortwave and longwave bands; the system has completed the loading and configuration of all preset threshold parameters (shortwave drop threshold, longwave drop threshold, shortwave rise threshold, differential judgment threshold, steady-state fluctuation threshold) locally; the communication link between the optical amplifier gain control module and the local decision module is normal.

[0044] The local logic decision module reads the cached shortwave power change and longwave power change, and executes the three-level branch logic decision in sequence; First-level branch determination: Determine that the change in shortwave power is less than the preset shortwave drop threshold, and the change in longwave power is less than the preset longwave drop threshold, and the difference between the two sets of changes meets the preset differential determination threshold; if all conditions are met, determine that the current segment is a fiber degradation segment, and directly jump to the gain compensation control process. Second-level branch determination: If the first-level branch conditions are not met, continue to determine if the change in shortwave power is greater than the preset shortwave rise threshold, while the change in longwave power is less than the preset longwave fall threshold; if all conditions are met, determine that the current segment is the downstream affected segment of the deterioration point, generate a control command to prohibit gain increase, do not perform any gain compensation operation, and the process ends directly. Third-level branch determination: If the conditions of the first two levels of branches are not met, it is determined that the absolute values ​​of the power changes in both groups are less than the steady-state fluctuation threshold; if the conditions are met, it is determined that there is no obvious abnormality in the link, the current optical amplifier gain parameters are kept unchanged, and the process ends directly. Gain compensation control process: Only when the judgment result is that the fiber in this segment is degraded, a gain adjustment command is sent to the optical amplifier on the receiving side of the current segment to control the amplifier to increase the gain to compensate for the additional loss of the link. The command is only sent to the amplifier in this segment and is not transmitted to any downstream amplifier. If the power change of the dual channels does not meet any of the above standard judgment modes, the current link is marked as an abnormal unknown condition, the delay confirmation protection logic is activated, and the traditional cross-segment loss calculation process is switched to perform secondary verification.

[0045] The judgment logic relies on the physical characteristics of stimulated Raman scattering in C+L broadband optical fiber: when fiber degradation occurs in the same span, both channels suffer additional losses and decrease synchronously, and the power decrease of the long-wave channel is greater than that of the short-wave channel; the downstream span of the degradation point is only affected by the reduction of the total power of the upstream. The energy transfer of the short-wave channel to the outside decreases, resulting in an increase in power, while the energy received by the long-wave channel decreases, resulting in a decrease in power. The combination of the two trends has a unique distinguishing feature. All decision-making logic is completed locally at a single site, eliminating the need to receive transmit power messages from upstream sites via the OSC channel, thus completely eliminating cross-site communication latency, protocol parsing latency, and site collaborative processing latency.

[0046] By relying on the combination of dual-channel power trends to achieve local independent fault determination, the positioning response speed is greatly improved; downstream disturbed segments are accurately isolated, and gain compensation is triggered only for truly degraded segments, thereby avoiding system disturbances such as overcompensation, power oscillation, and device saturation caused by the synchronous gain increase of multi-stage amplifiers from the root, and greatly improving the operational stability of high-capacity C+L transmission links.

[0047] Specifically, if the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, the current segment is determined to be an optical fiber deterioration segment. This includes determining that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, and the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition.

[0048] By refining the multi-layer threshold joint judgment rules through the corresponding step S103 segment degradation judgment branch logic, the degradation judgment rule is further refined. If the degradation segment is judged solely by the single condition of synchronous power decrease in both channels, it is impossible to distinguish between small normal power fluctuations and actual fiber additional loss. This can easily lead to the false triggering of gain compensation actions by slight link fluctuations, resulting in frequent small gain adjustments in the system and introducing additional power disturbances.

[0049] The local decision module reads two sets of quantization parameters: shortwave power change and longwave power change. First-level threshold judgment: The shortwave power change value is less than the preset shortwave drop threshold, and the longwave power change value is less than the preset longwave drop threshold, and obvious power attenuation occurs simultaneously in both channels. Second-level differential threshold judgment: Calculate the difference between the change in long-wave power and the change in short-wave power, and verify that the difference is less than the preset differential judgment threshold, which satisfies the unique physical characteristic of the deterioration segment that the long-wave attenuation amplitude is greater than the short-wave attenuation amplitude. Only when both threshold conditions are met simultaneously is the current segment determined to be a fiber degradation segment and the gain compensation control process is initiated; if any threshold condition is not met, the degradation determination branch is exited directly and the logic of the downstream segment or the no-abnormal branch is entered.

[0050] The two-layer threshold joint judgment relies on the physical law of stimulated Raman scattering, which degrades the synchronous attenuation of the dual channels in the segment and the attenuation of the long wavelength is greater. The superposition of the two conditions greatly improves the uniqueness of the judgment. All threshold parameters can be flexibly configured according to fiber type, segment length and service fill rate to adapt to different transmission link scenarios.

[0051] The dual thresholds are used to filter out minor normal power fluctuations, and the segment is only identified as degraded when there is a significant additional loss in the link, thus reducing system disturbances caused by frequent small gain adjustments of the amplifier. Differential verification is performed based on inherent physical characteristics, which has a much higher discrimination degree than single-channel threshold judgment, and the fault judgment accuracy is significantly improved.

[0052] Wherein, if the optical power received by the shortwave band out-of-band optical monitoring channel is higher than the corresponding reference value and the optical power received by the longwave band out-of-band optical monitoring channel is lower than the corresponding reference value, the current segment is determined to be the downstream affected segment of the degradation point. This includes determining that the power change of the shortwave band out-of-band optical monitoring channel is greater than the downstream disturbed segment determination branch logic in the corresponding step S103, and supplementing the control instruction generation refinement process.

[0053] If only the downstream segment is determined to be affected by power disturbance, and no control command to prohibit gain increase is issued simultaneously, the site gain control module will still automatically trigger gain compensation, causing downstream multi-stage amplifiers to simultaneously increase their gain, resulting in serious service failures such as power overshoot, amplifier saturation, and link power oscillation.

[0054] After the local decision module determines that the threshold condition for the first-level deterioration segment is not met, it initiates the downstream segment decision logic. The shortwave power change is verified to be greater than the preset shortwave rise threshold, while the longwave power change is less than the preset longwave fall threshold, matching the unique combination of shortwave power rise and longwave power fall trends in the downstream segment of the degradation point. When both threshold conditions are met, the current segment is determined to be the downstream affected segment of the deterioration point; The local decision module sends a permanent prohibition of gain boost control command to the gain control module of the receiving side of this segment. The command remains in effect until the power change of the dual channels returns to the steady-state fluctuation threshold range. Upon receiving the prohibition command, the gain control module locks the current amplifier gain parameters, rejects any gain increase adjustment requests, maintains the existing gain output, and the process ends directly without performing any compensation actions.

[0055] The gain restriction command is only sent to the current downstream amplifier segment that is currently identified as being disturbed, and will not be sent to other sites in the network; the command continuously locks the gain parameters until the dual-channel power trend returns to normal, avoiding repeated triggering of gain adjustments by instantaneous power fluctuations; the trend combination is unique and will not be confused with the degradation or abnormal link status of this segment.

[0056] By rigidly locking the gain of downstream cross-segment amplifiers at the control command level, the system power oscillation and device saturation problems caused by the synchronous gain increase of multi-stage amplifiers are completely eliminated; the command is issued locally in real time without any transmission delay, and the error compensation action can be blocked instantly when a fault occurs, ensuring the stable transmission of high-capacity C+L services.

[0057] In some embodiments, the pre-storing of the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber span under normal conditions without degradation includes collecting the received optical power values ​​of the two optical monitoring channels under different service channel loading states and different ambient temperature ranges when each optical fiber span is free from degradation, generating multiple sets of corresponding matching reference values ​​and storing them in categories.

[0058] Traditional single-set references are only suitable for a single service and temperature condition. When the number of service channels increases or decreases, or the temperature of the equipment room changes, the intensity of stimulated Raman scattering changes, and the steady-state power of the dual channels will have an inherent offset. This will cause normal operating conditions to be misjudged as link degradation, resulting in a high misjudgment rate of fault diagnosis.

[0059] After the system baseline acquisition mode is started, the operation and maintenance personnel adjust the link operation status in multiple working conditions. After each working condition has been running stably for a preset time, the dual-channel power acquisition is started. The first set of operating conditions is configured as sparse loading of service channels and low temperature range of the computer room. Hundreds of sets of raw power values ​​of dual channels are continuously collected, and the average value is smoothed to generate the first set of matching benchmarks. The second set of operating conditions is configured with full load of service channels and standard room temperature range. Similarly, hundreds of sets of raw power values ​​are collected, averaged and smoothed to generate the second set of matching benchmarks. The third set of operating conditions is configured with full load of service channels and high temperature range in the computer room. The raw power values ​​are collected and smoothed to generate the third set of matching benchmarks. The three sets of baseline data are bound to the corresponding business loading interval and temperature interval labels, and stored locally in the storage unit of each cross-segment receiving side in the form of an index table. The system monitors the number of services loaded and the temperature of the computer room in real time during daily operation. When the operating conditions switch across intervals, it automatically retrieves the dual-channel reference values ​​of the corresponding interval for subsequent change calculations. A baseline update is automatically triggered once per quarter. If the business scale or data center temperature control strategy is adjusted within the quarter, the full-condition baseline is immediately manually triggered to re-collect and overwrite the old baseline data.

[0060] Multiple sets of benchmarks are independently bound to operating condition labels, and the benchmark data do not interfere with each other between different operating conditions; the benchmark data is stored locally only and does not need to be synchronized to upstream and downstream sites; each collection uses multiple sets of numerical averages for smoothing, and instantaneous power noise is removed to ensure that the benchmark values ​​closely match the real steady-state operating conditions.

[0061] By covering all normal operating conditions of the transmission system, the inherent power offset of the dual channels caused by service scheduling and changes in ambient temperature is completely eliminated, significantly reducing the probability of fault misjudgment; the reference data is automatically matched with the real-time operating conditions, and no manual switching of the reference is required throughout the process, which is highly automated and suitable for long-term unattended backbone optical transmission site operation and maintenance scenarios.

[0062] In some embodiments, the receiving side of each optical fiber segment collects the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time, including collecting the original received optical power values ​​of the two optical monitoring channels according to a preset sampling period, performing short-time noise reduction processing on the original values, and outputting the processed received optical power values.

[0063] In the corresponding step S102 of the embodiment, a filtering preprocessing procedure is added to the acquired raw power data.

[0064] The optical power monitoring module outputs instantaneous noise jumps. Fiber microbending, electromagnetic interference in the equipment room, and instantaneous fluctuations in devices can all cause sudden changes in power values ​​during a single sampling period. Directly using the original values ​​to calculate the changes can lead to erroneous triggering of the judgment logic, resulting in frequent false degradation alarms.

[0065] The monitoring module synchronously collects the raw received optical power values ​​of shortwave and longwave dual channels according to the preset sampling period, and temporarily stores each set of raw values ​​into the local cache queue. Configure a fixed-length sliding filter window, and continuously store the number of consecutively sampled raw power data of the window size in the buffer queue; Whenever the buffer queue is full of a complete window of data, the arithmetic mean is calculated on all the original power values ​​in the window, and a set of smoothed and filtered stable power values ​​are output. The buffer queue is then cleared and the storage of the next window of original data is restarted. The filtered dual-channel stable power value is transmitted to the change calculation unit. The original value of the original jump is only temporarily cached locally and does not participate in subsequent difference calculation and fault determination. Maintenance personnel can adjust the filter window length according to the type of fiber optic cable and the accuracy of the monitoring device: longer windows are configured for long-distance cross-segments to suppress long-distance transmission noise, while shorter windows are configured for short-distance metropolitan cross-segments to ensure monitoring response speed.

[0066] The filtering process is completed locally on the single-segment receiving side, without occupying cross-site OSC channel transmission resources; the raw noise data is only temporarily buffered and does not occupy the storage unit for a long time; the window length can be flexibly configured to take into account both the monitoring response speed and data smoothness requirements.

[0067] By filtering instantaneous random power noise, the power values ​​used in fault determination are made to match the actual steady-state power level of the link, significantly reducing false fiber degradation alarms and reducing the workload of maintenance personnel in unnecessary inspections; the filtering process is lightweight and does not increase the local computing power burden of the site, making it compatible with low-computing-power embedded site hardware.

[0068] In some embodiments, calculating the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value includes selecting a reference value that matches the current service channel loading status and the current ambient temperature, and calculating the difference between the current received optical power of the two optical monitoring channels and the matching reference value as the power change of the corresponding channel.

[0069] The logic for benchmark matching and difference calculation is refined through the power change calculation step S102.

[0070] When calculating the power difference using a fixed single benchmark, the current service and temperature conditions are not distinguished. The calculated change includes the inherent power offset of the operating conditions, which cannot truly reflect the power attenuation caused by the additional loss of the optical fiber, resulting in low reliability of the judgment result.

[0071] The system collects the total number of online loads for cross-segment service channels and the real-time ambient temperature of the computer room in real time, and transmits the two sets of operating parameters to the change calculation unit simultaneously. The computing unit reads the multidimensional benchmark index table stored locally, traverses all benchmark operating condition labels in the table, and accurately matches a set of shortwave benchmark values ​​and longwave benchmark values ​​that completely overlap in the business loading range and temperature range. The change in shortwave channel power is obtained by subtracting the shortwave reference value under the matching condition from the real-time shortwave power value after filtering; the change in longwave channel power is obtained by subtracting the longwave reference value under the matching condition from the real-time longwave power value after filtering. The two sets of power change values ​​are bound to the current operating condition label and cached together and transmitted to the local decision module for use by the trend judgment logic. If the current operating conditions cannot match any of the preset benchmarks in the table, the system will automatically retrieve the default normal temperature and medium business load benchmarks for temporary calculations. At the same time, an abnormal operating condition record will be generated and stored in the background to remind maintenance personnel to collect the corresponding operating condition benchmarks.

[0072] The entire process is automated through real-time synchronization of operating parameters and automatic matching of benchmarks, requiring no manual intervention. The difference calculation is completed locally and does not rely on any monitoring data from upstream sites. When there is no matching operating condition, a temporary benchmark is activated and alarm records are retained, balancing the continuous operation of the system with the improvement of benchmark data.

[0073] The inherent power offset caused by business operations and temperature is completely eliminated, and the power change only reflects the power offset caused by the additional loss of the fiber optic link, which greatly improves the accuracy of the quantitative indicators; the automated matching logic does not require manual intervention and is compatible with backbone transmission networks that operate 24 / 7.

[0074] In some embodiments, triggering gain compensation for the receiving-side optical amplifier in a segment determined to be a fiber degradation segment includes sending a gain adjustment command only to the optical amplifier in the current segment receiving side, controlling the optical amplifier to increase the corresponding gain to compensate for the additional loss generated in the current segment, and not sending a gain increase command to the optical amplifier in the downstream segment.

[0075] The gain compensation control process in step S103 is used to refine the logic for limiting the range of gain commands.

[0076] Traditional collaborative judgment schemes will simultaneously issue gain adjustment commands to multiple upstream and downstream sites, and multiple cross-segment amplifiers will simultaneously increase the gain, resulting in overcompensation. This causes severe overshoot of the link output power, damaging optical transmission devices and degrading the signal-to-noise ratio of services.

[0077] After the local decision module completes the fiber degradation determination for this segment, it generates a dedicated gain adjustment command, which only carries the current local segment site identifier. The gain control module only receives gain adjustment commands with local site identifiers. After identifying the command and matching the local site identifier, it reads the current additional loss amplitude of the link and calculates the corresponding amplifier gain increase. A gain boosting control signal is sent to the optical amplifier on the receiving side of this segment. The amplifier increases the output gain according to the calculated amplitude to compensate for the additional loss caused by fiber degradation. Gain adjustment commands are transmitted only within the local site and will not be forwarded to any downstream cross-segment sites through the OSC channel or operation and maintenance management channel; downstream cross-segment amplifiers have no gain adjustment command input and maintain their original gain parameters unchanged. After the power change of the dual channels returns to the steady-state range, a gain callback command is automatically issued to restore the amplifier gain to the normal operating parameters.

[0078] By binding the gain command to a unique identifier of the local site, the scope of command issuance is naturally limited, preventing cross-site gain synchronization adjustments; the gain increase is matched with the actual additional loss of the link, achieving precise and appropriate compensation and avoiding excessive gain increase; gain callback is executed automatically, and normal operating parameters are automatically restored after the link fault is repaired.

[0079] Gain compensation is performed only on the single segment that actually deteriorates, while all downstream segment amplifiers maintain their original gain, eliminating system faults such as power overshoot, amplifier saturation, and link oscillation caused by multi-stage synchronous compensation from the root cause; the gain compensation amplitude matches the link loss, taking into account both the speed of service recovery and the operational safety of transmission devices.

[0080] In some embodiments, the method further includes stopping the local fast judgment process and switching to a cross-segment loss calculation process based on the transmission power of the upstream site for degradation location verification when the power change trend of the two optical monitoring channels does not meet the preset judgment mode.

[0081] The gain compensation control process in step S103 is used to refine the logic for limiting the range of gain commands.

[0082] Traditional collaborative judgment schemes will simultaneously issue gain adjustment commands to multiple upstream and downstream sites, and multiple cross-segment amplifiers will simultaneously increase the gain, resulting in overcompensation. This causes severe overshoot of the link output power, damaging optical transmission devices and degrading the signal-to-noise ratio of services.

[0083] After the local decision module completes the fiber degradation determination for this segment, it generates a dedicated gain adjustment command, which only carries the current local segment site identifier. The gain control module only receives gain adjustment commands with local site identifiers. After identifying the command and matching the local site identifier, it reads the current additional loss amplitude of the link and calculates the corresponding amplifier gain increase. A gain boosting control signal is sent to the optical amplifier on the receiving side of this segment. The amplifier increases the output gain according to the calculated amplitude to compensate for the additional loss caused by fiber degradation. Gain adjustment commands are transmitted only within the local site and will not be forwarded to any downstream cross-segment sites through the OSC channel or operation and maintenance management channel; downstream cross-segment amplifiers have no gain adjustment command input and maintain their original gain parameters unchanged. After the power change of the dual channels returns to the steady-state range, a gain callback command is automatically issued to restore the amplifier gain to the normal operating parameters.

[0084] By binding the gain command to a unique identifier of the local site, the scope of command issuance is naturally limited, preventing cross-site gain synchronization adjustments; the gain increase is matched with the actual additional loss of the link, achieving precise and appropriate compensation and avoiding excessive gain increase; gain callback is executed automatically, and normal operating parameters are automatically restored after the link fault is repaired.

[0085] Gain compensation is performed only on the single segment that actually deteriorates, while all downstream segment amplifiers maintain their original gain, eliminating system faults such as power overshoot, amplifier saturation, and link oscillation caused by multi-stage synchronous compensation from the root cause; the gain compensation amplitude matches the link loss, taking into account both the speed of service recovery and the operational safety of transmission devices.

[0086] In some embodiments, the method further includes, after completing the current segment degradation determination, reading the power change determination result of the downstream adjacent segment, and when the downstream adjacent segment is determined to be a downstream affected segment of degradation point, increasing the confidence level of the current segment degradation determination result.

[0087] After completing the corresponding step S103, the background auxiliary verification supplementary process is completed, and adjacent cross-segment consistency verification logic is added.

[0088] Relying solely on the power trend of a single span with dual channels to determine the deterioration of a span can lead to erroneous deterioration judgments if a momentary failure occurs in the monitoring device of a single channel. Furthermore, the lack of auxiliary verification methods to improve the reliability of the judgment results makes it difficult to make accurate judgments.

[0089] After the local judgment module completes the basic judgment of fiber degradation in the current segment, it does not immediately lock the judgment result. Instead, it asynchronously starts the consistency verification logic of adjacent segments in the background. The background verification does not consume the computing power of the main judgment process and does not affect the fault location response speed. The local site reads the real-time judgment results stored on the downstream adjacent cross-segment receiving side through the operation and maintenance management channel; Verify whether the current judgment result of the downstream adjacent span is a deterioration point downstream affected span, that is, the power trend of the dual channels of the downstream span is short wave rising and long wave falling; If the judgment result of the downstream adjacent span matches the downstream disturbance characteristics, the confidence level of the current span degradation judgment will be raised to the highest level, and a high-priority fault alarm will be generated and pushed to the operation and maintenance platform. If the downstream adjacent segment is judged to be without abnormality or is also judged to be a deteriorated segment, the current basic confidence level is maintained, a normal priority alarm is generated, and the background continuously retains the adjacent segment judgment comparison log for subsequent fault tracing.

[0090] The consistency check between adjacent segments is used as an asynchronous auxiliary logic in the background, which is independent of the serial link of the main judgment process. It will not increase the latency of the main judgment process or reduce the speed of fault location. It only reads the judgment results that have been completed in the downstream segment, and there is no need to collect the raw power data of the downstream dual channels in real time. The amount of cross-site interaction data is extremely small and will not occupy OSC channel transmission resources.

[0091] By leveraging the inherent linkage characteristics of upstream and downstream cross-segment power trends for auxiliary consistency verification, the system distinguishes between genuine single-segment fiber degradation and instantaneous faults in single-channel monitoring devices, thereby improving the reliability of fault determination results. The asynchronous execution in the background does not affect the core performance of rapid location, balancing the dual requirements of millisecond-level rapid response and high accuracy in fault determination.

[0092] In some embodiments, as the capacity of backbone and metropolitan area optical transmission systems continues to increase, transmission systems are expanding from traditional C-band to C+L multi-band transmission architecture. Compared with single C-band systems, C+L systems carry a significantly increased number of service wavelengths and total service capacity, placing higher demands on the rapid detection, location, and recovery of fiber optic link anomalies.

[0093] In multi-span optical transmission systems, fiber degradation or fiber faults are common types of failures. Common causes include loose fiber connectors, road construction, pipeline construction, bending, compression, or other human activities. When additional loss occurs in a span, the input optical power at the receiving end of that span decreases; without timely compensation, the received optical power of all spans downstream of the degradation point will also decrease.

[0094] To avoid service performance degradation or even interruption, the system typically needs to adjust the gain of the optical amplifiers on the receiving side of the degraded segment. The key issue is that the system must identify the segment where the degradation has actually occurred, and cannot allow multiple optical amplifiers downstream of the degradation point to simultaneously increase their gain; otherwise, it may cause overcompensation, amplifier saturation, power oscillation, and unnecessary system disturbances.

[0095] In existing solutions, each span is typically configured with an Optical Monitoring Channel (OSC) that terminates segment by segment. The transmitting side of a given span transmits monitoring information, such as the total transmitted optical power of that span, to the receiving side via the OSC. When the receiving optical amplifier detects a decrease in received optical power, it combines this information with the total transmitted optical power transmitted from the upstream adjacent optical amplifier via the OSC to calculate the current span's loss and compare it with the normal maintenance value. If the current span's loss significantly increases, it is determined that degradation occurred in that span.

[0096] This scheme can distinguish between a degraded segment and its downstream segments, but its determination relies on information transmission and protocol processing between adjacent stations, essentially belonging to a station-to-station collaborative determination mechanism. For C+L systems, the impact on services is greater during anomalies, requiring faster triggering of correct gain recovery actions; existing schemes are limited by OSC communication latency, protocol packet processing latency, and station control logic processing latency, resulting in bottlenecks in segment location speed.

[0097] Therefore, there is a need for a rapid location method that does not require waiting for upstream sites to send power information and allows each optical amplifier site to independently determine whether degradation has occurred in its own segment based on local received monitoring data.

[0098] This invention utilizes the inter-wavelength power transfer characteristics caused by stimulated Raman scattering (SRS) in the C+L system. An out-of-band OSC channel is set up or multiplexed on both the short-wavelength side of the C-band and the long-wavelength side of the L-band. For example, the short-wavelength OSC channel λS≈1520nm and the long-wavelength OSC channel λL≈1625nm. The received optical power of the two OSC channels λS and λL is monitored at each cross-band receiver and compared with the normal reference value for that cross-band.

[0099] Within the same fiber span, SRS generally exhibits the behavior of transferring energy from short-wavelength channels to long-wavelength channels. λS is located on the short-wavelength side of the C-band and typically transfers power to longer-wavelength channels such as the C-band, L-band, and λL; λL is located on the long-wavelength side of the L-band and typically receives power transfer from shorter-wavelength channels such as the C-band, L-band, and λS.

[0100] When fiber optic link degradation occurs in a certain span, both λS and λL within that span are affected by the newly added link loss, resulting in a decrease in the received optical power of both. Due to the weakening of the SRS coupling effect, the decrease in λS is less than the increase in loss itself, while the decrease in λL is greater than the increase in loss itself. For the degraded span, the received power of both out-of-band OSCs shows a decreasing trend relative to the normal state.

[0101] For the downstream segment of the degradation point, the degradation does not occur within the downstream segment itself. The main changes within the downstream segment stem from the reduced power of the C+L service channels and other channels entering the segment, causing alterations in the SRS intensity within that segment. Due to reduced energy transfer from longer-wavelength channels to λS, λS tends to increase relative to normal at the receiver side of this downstream segment; conversely, reduced energy transfer from shorter-wavelength channels to λL tends to decrease relative to normal at the receiver side of this downstream segment. Therefore, the difference between "λS and λL decreasing together" and "λS increasing while λL decreasing" can be used to distinguish between the degraded segment and the downstream affected segment.

[0102] like Figure 2 , Figure 3 and Figure 4 As shown, this invention utilizes the inter-wavelength power transfer characteristics caused by stimulated Raman scattering (SRS) in the C+L system, setting or multiplexing an out-of-band OSC channel on the short-wavelength side of the C-band and the long-wavelength side of the L-band, for example, the short-wavelength OSC channel λS≈1520nm and the long-wavelength OSC channel λL≈1625nm. The received optical power of the two OSC channels λS and λL is monitored at each cross-band receiver and compared with the normal reference value for that cross-band.

[0103] Within the same fiber span, SRS generally exhibits the behavior of transferring energy from short-wavelength channels to long-wavelength channels. λS is located on the short-wavelength side of the C-band and typically transfers power to longer-wavelength channels such as the C-band, L-band, and λL; λL is located on the long-wavelength side of the L-band and typically receives power transfer from shorter-wavelength channels such as the C-band, L-band, and λS.

[0104] When fiber optic link degradation occurs in a certain span, both λS and λL within that span are affected by the newly added link loss, resulting in a decrease in the received optical power of both. Due to the weakening of the SRS coupling effect, the decrease in λS is less than the increase in loss itself, while the decrease in λL is greater than the increase in loss itself. For the degraded span, the received power of both out-of-band OSCs shows a decreasing trend relative to the normal state.

[0105] For the downstream segment of the degradation point, the degradation does not occur within the downstream segment itself. The main changes within the downstream segment stem from the reduced power of the C+L service channels and other channels entering the segment, causing alterations in the SRS intensity within that segment. Due to reduced energy transfer from longer-wavelength channels to λS, λS tends to increase relative to normal at the receiver side of this downstream segment; conversely, reduced energy transfer from shorter-wavelength channels to λL tends to decrease relative to normal at the receiver side of this downstream segment. Therefore, the difference between "λS and λL decreasing together" and "λS increasing while λL decreasing" can be used to distinguish between the degraded segment and the downstream affected segment.

[0106] like Figure 2 As shown, Figure 2 This is a schematic diagram of a multi-span C+L optical transmission system. The system includes multiple cascaded fiber spans, with optical amplifier sites at both ends of each span. In addition to the service C-band and L-band, a short-wave OSC channel λS and a long-wave OSC channel λL are provided. The receiving side of each span monitors the received power of the two OSC channels. Specifically, this includes: (1) Multi-segment C+L optical transmission link, including multiple fiber spans and optical amplifier sites at both ends of each span.

[0107] (2) Shortwave out-of-band OSC channel λS, whose wavelength is shorter than the C-band service wavelength range, for example, about 1520nm.

[0108] (3) The long-wavelength out-of-band OSC channel λL has a wavelength longer than the L-band service wavelength range, for example, about 1625nm.

[0109] (4) The OSC receiving power monitoring module on the receiving side of each segment is used to obtain PS,k and PL,k respectively, where k represents the kth segment.

[0110] (5) Reference maintenance module, used to maintain the received optical power reference PS,k,0 and PL,k,0 of each cross-segment two OSC channels under normal conditions without degradation, and can also maintain multiple sets of references corresponding to temperature, wavelength configuration and service load status.

[0111] (6) Local decision module, used to calculate the change of the two OSC channels relative to the baseline, and determine whether the current segment is a deteriorated segment based on the change trend.

[0112] (7) Gain control module, used to trigger the optical amplifier on the receiving side of the current segment to perform gain adjustment only after it is determined that the current segment has deteriorated.

[0113] like Figure 3 As shown, Figure 3 This is a schematic diagram illustrating the OSC power variation trends of the degraded segment and downstream segments. When additional loss occurs in the k-th segment, the receiver side of the k-th segment shows a decrease in λS and a decrease in λL; the receiver side of the (k+1)-th and further downstream segments shows an increase in λS and a decrease in λL.

[0114] Meanwhile, for the k-th segment, the power variation of the two OSC channels is defined on the receiving side as follows: ΔS,k=PS,k(t) PS,k,0 ΔL,k=PL,k(t) PL,k,0 Where PS,k(t) and PL,k(t) represent the received optical power of the shortwave OSC and longwave OSC at the current moment, respectively, and PS,k,0 and PL,k,0 represent the reference received optical power of this segment under normal conditions. The power unit can be dBm, and the unit of change can be dB.

[0115] A basic judgment rule is as follows: (1) If ΔS,k < TS and ΔL,k < If TL is reached, it is determined that both OSC channels are decreasing in the current segment; when ΔL,k < ΔS,k is satisfied simultaneously. If TD or the preset differential characteristics are met, the degradation is determined to have occurred in the k-th segment.

[0116] (2) If ΔS,k>+TU and ΔL,k< If TL is selected, it is determined that the current span is downstream of the degradation point, and the current span itself has not experienced fiber degradation, so the gain increase of this span is not triggered.

[0117] (3) If |ΔS,k|≤TN and |ΔL,k|≤TN, then it is determined that there is no obvious abnormality in the current segment.

[0118] (4) If an abnormal combination that does not meet the above pattern occurs, the process will proceed to protection decision, delayed confirmation, or rollback to the traditional OSC cross-loss calculation process.

[0119] TS, TL, TU, TD, and TN are configurable thresholds that can be determined based on OSC monitoring accuracy, link noise, SRS strength, service channel fill rate, span length, fiber type, and optical amplifier gain control accuracy.

[0120] like Figure 4 As shown, Figure 4 This is a flowchart of the method of the present invention, including steps such as baseline maintenance, real-time monitoring, change calculation, trend judgment, gain control, and verification rollback. The corresponding process includes: (1) Initialization phase: When the system is running normally and there is no fiber degradation, record the received power reference of the two OSC channels λS and λL in each span; a multi-dimensional reference table can be established according to wavelength configuration, service load and temperature range.

[0121] (2) Real-time monitoring stage: The receiving power of λS and λL is periodically collected at each cross-segment receiving side optical amplifier station, and noise reduction, moving average or short-time filtering is performed.

[0122] (3) Change calculation stage: ΔS,k and ΔL,k are calculated locally without waiting for the upstream site to send the total optical power information through OSC.

[0123] (4) Trend judgment stage: Based on the changing trends of the two OSC channels, identify whether this segment is a deteriorated segment, whether it is a downstream affected segment, or whether there is no abnormality.

[0124] (5) Gain control stage: Gain compensation is initiated only when the local decision result is "degradation occurs in this segment". When the decision result is "downstream affected segment", the gain is not actively increased to avoid multi-level compensation at the same time.

[0125] (6) Verification and rollback stage: If the power change trend is unstable or the threshold confidence is insufficient, the traditional OSC method of carrying the upstream transmission power cross-loss calculation method is retained as a secondary verification or rollback mechanism.

[0126] For example, the method also includes: (1) Enhanced difference index: Construct Dk=ΔL,k ΔS,k. In the segment where degradation occurs, Dk is typically more negative; in the downstream segment, ΔS,k is usually positive, ΔL,k is negative, and Dk is also negative but with a different sign combination. Reliability can be improved by combining the sign and differential amplitude.

[0127] (2) Consistency check between adjacent points: When a certain segment is determined to be deteriorated and its downstream adjacent segments show an increase in λS and a decrease in λL, the confidence of the determination is increased. However, this check is not required for the main determination and can be performed in the background without affecting the fast response.

[0128] (3) Service channel load normalization: When the C / L service wavelength filling status changes, the benchmark can be corrected according to the total service power or channel loading information to reduce the impact of service scheduling on the SRS change trend.

[0129] (4) Multi-threshold grading: Set a fast trigger threshold and a confirmation threshold. Fast trigger is used for initial judgment at the millisecond or sub-second level, and the confirmation threshold is used for subsequent stable control.

[0130] (5) Applicable wavelength extension: λS is not limited to 1520nm, and λL is not limited to 1625nm. As long as λS is located on the short-wave side of the C-band service wavelength and λL is located on the long-wave side of the L-band service wavelength, and both can reflect the relative power change trend caused by SRS, they are all within the protection scope of this invention.

[0131] The method provided in this application has the following beneficial effects: (1) Fast positioning speed: Each station directly judges based on the local change trend of the received power of the two OSCs in this segment, without relying on the transmission and protocol processing of the power information sent by adjacent stations, which can significantly shorten the identification time of degraded segments.

[0132] (2) Avoid false triggering of downstream optical amplifiers: By distinguishing the degradation segment characteristics of "both OSCs decreasing at the same time" and the downstream segment characteristics of "short-wave OSC increasing and long-wave OSC decreasing", the gain of multiple optical amplifiers downstream of the degradation point is not increased at the same time.

[0133] (3) Fully reuse existing resources of C+L system: C+L system usually requires OSC or monitoring channels outside C band and outside L band. This solution can reuse such out-of-band channels and receive power monitoring capabilities with minimal hardware modifications.

[0134] (4) Suitable for C+L multi-band systems: This scheme utilizes the more obvious SRS characteristics in C+L broadband transmission to transform the physical effects that may have caused spectral tilt into cross-band degradation location characteristics.

[0135] (5) Better control stability: After quickly identifying the truly degraded segment, compensation is performed only by the optical amplifier on the receiving side of that segment, which can reduce the risk of amplifier oversaturation, cascade oscillation and power overshoot.

[0136] (6) Compatible with existing solutions: This solution can be used as a fast initial judgment mechanism and can run in parallel with the traditional cross-loss calculation mechanism based on OSC to transmit upstream transmission power. The latter is used for confirmation, calibration or abnormal mode backoff.

[0137] Please see Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of a multi-span optical transmission system fiber degradation rapid location system 200 provided in this application embodiment. The multi-span optical transmission system fiber degradation rapid location system 200 is used to execute the steps of the multi-span optical transmission system fiber degradation rapid location method shown in the above embodiments. The multi-span optical transmission system fiber degradation rapid location system 200 can be a single server or a server cluster, or it can be a terminal, such as a handheld terminal, laptop computer, wearable device, or robot.

[0138] like Figure 5 As shown, the fiber degradation rapid location system 200 for multi-segment optical transmission systems includes: Normal storage unit 201 is used to pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The numerical monitoring unit 202 is used to collect the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time at each optical fiber segment receiving side; and to calculate the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. The action triggering unit 203 is used to make local judgments based on the power change trends of the two optical monitoring channels. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. When the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be a downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. The gain compensation action is triggered on the receiving-side optical amplifier of the segment determined to be a fiber degradation segment.

[0139] In some embodiments, the pre-storing of the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber span under normal conditions without degradation includes collecting the received optical power values ​​of the two optical monitoring channels under different service channel loading states and different ambient temperature ranges when each optical fiber span is free from degradation, generating multiple sets of corresponding matching reference values ​​and storing them in categories.

[0140] In some embodiments, the receiving side of each optical fiber segment collects the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time, including collecting the original received optical power values ​​of the two optical monitoring channels according to a preset sampling period, performing short-time noise reduction processing on the original values, and outputting the processed received optical power values.

[0141] In some embodiments, calculating the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value includes selecting a reference value that matches the current service channel loading status and the current ambient temperature, and calculating the difference between the current received optical power of the two optical monitoring channels and the matching reference value as the power change of the corresponding channel.

[0142] In some embodiments, triggering gain compensation for the receiving-side optical amplifier in a segment determined to be a fiber degradation segment includes sending a gain adjustment command only to the optical amplifier in the current segment receiving side, controlling the optical amplifier to increase the corresponding gain to compensate for the additional loss generated in the current segment, and not sending a gain increase command to the optical amplifier in the downstream segment.

[0143] In some embodiments, the method further includes stopping the local fast judgment process and switching to a cross-segment loss calculation process based on the transmission power of the upstream site for degradation location verification when the power change trend of the two optical monitoring channels does not meet the preset judgment mode.

[0144] In some embodiments, the method further includes, after completing the current segment degradation determination, reading the power change determination result of the downstream adjacent segment, and when the downstream adjacent segment is determined to be a downstream affected segment of degradation point, increasing the confidence level of the current segment degradation determination result.

[0145] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the multi-span optical transmission system fiber degradation cross-segment rapid location system and each module described above can be referred to the corresponding content in the various embodiments of the multi-span optical transmission system fiber degradation cross-segment rapid location method, and will not be repeated here.

[0146] The aforementioned method for rapid location of fiber degradation segments in multi-span optical transmission systems can be implemented as a computer program, which can be used in various ways, such as... Figure 5 It runs on the system shown.

[0147] Please see Figure 6 , Figure 6 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application. The computer device includes a processor, a memory, and a network interface connected via a device bus, wherein the memory may include a storage medium and internal memory.

[0148] The storage medium can store operating devices and computer programs. The computer program includes program instructions that, when executed, cause the processor to perform any method for rapid location of fiber degradation in a multi-span optical transmission system.

[0149] The processor provides computing and control capabilities, supporting the operation of the entire computer device.

[0150] The internal memory provides an environment for the execution of computer programs in non-volatile storage media. When the computer program is executed by the processor, it enables the processor to perform any method for rapid location of fiber degradation in a multi-span optical transmission system.

[0151] This network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the terminal to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0152] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0153] In one embodiment, the processor is configured to run a computer program stored in memory to perform the following steps: Pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The receiving side of each optical fiber segment collects the received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel in real time; and calculates the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. Local determination is made based on the power change trends of the two optical monitoring channels. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. Furthermore, if the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be a downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. Gain compensation is triggered on the receiving-side optical amplifier of the segment determined to be a fiber degradation segment.

[0154] In some embodiments, the pre-storing of the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber span under normal conditions without degradation includes collecting the received optical power values ​​of the two optical monitoring channels under different service channel loading states and different ambient temperature ranges when each optical fiber span is free from degradation, generating multiple sets of corresponding matching reference values ​​and storing them in categories.

[0155] In some embodiments, the receiving side of each optical fiber segment collects the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time, including collecting the original received optical power values ​​of the two optical monitoring channels according to a preset sampling period, performing short-time noise reduction processing on the original values, and outputting the processed received optical power values.

[0156] In some embodiments, calculating the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value includes selecting a reference value that matches the current service channel loading status and the current ambient temperature, and calculating the difference between the current received optical power of the two optical monitoring channels and the matching reference value as the power change of the corresponding channel.

[0157] In some embodiments, triggering gain compensation for the receiving-side optical amplifier in a segment determined to be a fiber degradation segment includes sending a gain adjustment command only to the optical amplifier in the current segment receiving side, controlling the optical amplifier to increase the corresponding gain to compensate for the additional loss generated in the current segment, and not sending a gain increase command to the optical amplifier in the downstream segment.

[0158] In some embodiments, the method further includes stopping the local fast judgment process and switching to a cross-segment loss calculation process based on the transmission power of the upstream site for degradation location verification when the power change trend of the two optical monitoring channels does not meet the preset judgment mode.

[0159] In some embodiments, the method further includes, after completing the current segment degradation determination, reading the power change determination result of the downstream adjacent segment, and when the downstream adjacent segment is determined to be a downstream affected segment of degradation point, increasing the confidence level of the current segment degradation determination result.

[0160] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to implement the steps of the method for rapid location of fiber degradation segments in a multi-segment optical transmission system as provided in any embodiment of this application.

[0161] The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the computer device.

[0162] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for rapid location of fiber degradation segments in a multi-span optical transmission system, characterized in that, include: Pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The receiving side of each optical fiber segment collects the received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel in real time; and calculates the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. Based on the power change trend of the two optical monitoring channels, local judgment is made. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. When the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be the downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. The receiver-side optical amplifier is triggered to perform gain compensation for the fiber segment identified as degraded.

2. The method according to claim 1, characterized in that, The pre-stored reference values ​​of the received optical power at the receiving side of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel under normal, non-degradation conditions for each fiber span include: The received optical power values ​​of the two optical monitoring channels are collected under different service channel loading states and different ambient temperature ranges when there is no degradation in each fiber span. Multiple sets of corresponding matching reference values ​​are generated and stored in categories.

3. The method according to claim 1, characterized in that, The receiving side of each fiber optic segment collects the received optical power values ​​of the shortwave band out-of-band optical monitoring channel and the longwave band out-of-band optical monitoring channel in real time, including: The raw received optical power values ​​of the two optical monitoring channels are collected according to the preset sampling period. Short-term noise reduction processing is performed on the raw values, and the processed received optical power values ​​are output.

4. The method according to claim 1, characterized in that, The calculation of the power change between the current received optical power and the corresponding reference value for the two optical monitoring channels includes: Select a reference value that matches the current service channel loading status and the current ambient temperature, and calculate the difference between the current received optical power of the two optical monitoring channels and the matching reference value, as the power change of the corresponding channel.

5. The method according to claim 1, characterized in that, The triggering of gain compensation for the receiver-side optical amplifier in the segment determined to be a fiber degradation section includes: Send a gain adjustment command to the optical amplifier on the receiving side of the current segment to control the optical amplifier to increase the corresponding gain to compensate for the additional loss generated in the current segment, and do not send a gain increase command to the optical amplifier of the downstream segment.

6. The method according to claim 1, characterized in that, The method further includes: When the power change trends of the two optical monitoring channels do not meet the preset judgment mode, the local fast judgment process is stopped, and the process of cross-segment loss calculation based on the transmission power of the upstream site is switched to perform degradation location verification.

7. The method according to claim 1, characterized in that, The method further includes: After completing the current segment degradation determination, read the power change determination results of the downstream adjacent segment. When the downstream adjacent segment is determined to be a downstream affected segment of degradation point, increase the confidence level of the current segment degradation determination result.

8. A rapid fiber degradation segment location system for a multi-segment optical transmission system, used to implement the method as described in any one of claims 1-7, characterized in that, include: The normal storage unit is used to pre-store the received optical power reference values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel at the receiving side of each optical fiber segment under normal conditions without degradation. The wavelength of the short-wavelength out-of-band optical monitoring channel is shorter than the wavelength range of the short-wavelength service band, and the wavelength of the long-wavelength out-of-band optical monitoring channel is longer than the wavelength range of the long-wavelength service band. The numerical monitoring unit is used to collect the received optical power values ​​of the short-wavelength out-of-band optical monitoring channel and the long-wavelength out-of-band optical monitoring channel in real time at each optical fiber segment receiving side; and to calculate the power change between the current received optical power of the two optical monitoring channels and the corresponding reference value. The action triggering unit is used to make local judgments based on the power change trends of the two optical monitoring channels. If the received optical power of both optical monitoring channels is lower than the corresponding reference value and meets the preset drop threshold condition, it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is less than the preset short-wavelength drop threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold. When the difference between the power change of the long-wavelength channel and the power change of the short-wavelength channel meets the preset difference condition, the current segment is determined to be a fiber degradation segment. If it is determined that the power change of the short-wavelength out-of-band optical monitoring channel is greater than the preset rise threshold, and the power change of the long-wavelength out-of-band optical monitoring channel is less than the preset long-wavelength drop threshold, the current segment is determined to be the downstream affected segment of the degradation point, and a control command to prohibit gain increase in this segment is generated. The receiver-side optical amplifier is triggered to perform gain compensation for the fiber segment identified as degraded.

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