A multi-level fault diagnosis method and system for a communication system

Abstract

The application relates to the technical field of fault diagnosis, and relates to a multilevel fault diagnosis method and system for a communication system, which comprises the following steps: establishing three layers of node sets of a physical layer, a relay section and a multiplexing section, and longitudinal directed edges representing interlayer fault propagation relations; collecting laser bias current and optical power analog quantities, frame step-out events, B1 error code statistical values, B2 error codes and error block second counts in real time; when it is detected that the laser bias current of the physical layer node exceeds a preset aging threshold value, searching for the frame step-out event frequency change trend of the associated relay section node within a preset time window; when it is detected that the B2 error code of the multiplexing section node exceeds a preset threshold value, tracing back the B1 error code distribution characteristics of the associated relay section node, and further tracing back the optical power fluctuation characteristics of the physical layer node; and outputting fault types, fault occurrence times, single-block plugboard identification information to which the fault is located and fault confidence, so that cross-layer bidirectional tracing back and accurate positioning of faults are realized.

Description

Technical Field

[0001] This invention relates to the field of fault diagnosis technology, and more specifically, to a multi-level fault diagnosis method and system for communication systems. Background Technology

[0002] In SDH optical transmission systems, faults often exhibit hierarchical propagation characteristics. Physical layer laser aging leads to decreased optical power, which in turn causes frame synchronization loss in the relay section, ultimately manifesting as a surge in B2 bit errors in the multiplex section. Traditional fault diagnosis methods monitor and alarm for each layer separately, with parameter acquisition for the physical layer, relay section, and multiplex section operating independently, lacking a cross-layer correlation analysis mechanism. When a fault occurs, multiple layers simultaneously report a large number of alarms, making it difficult for maintenance personnel to quickly identify the cause of the fault amidst the alarm storm. Manual troubleshooting at each level is often required, resulting in low fault location efficiency. Furthermore, existing methods only support a one-way diagnostic mode that aggregates alarms from the physical layer upwards, failing to achieve reverse fault location by tracing the fault cause downwards from the multiplex section back to the physical layer, making it difficult to accurately pinpoint the fault to the individual circuit board level.

[0003] On the other hand, current technologies for monitoring laser bias current only use it for simple threshold alarms, failing to correlate it with the frequency trends of relay segment frame synchronization loss events, and thus unable to predict the impact of laser aging on upper-layer services. The impact of external environmental events on the performance of physical layer devices is also often handled independently, and false transmission alarms caused by environmental interference cannot be effectively identified and filtered. Therefore, an intelligent fault diagnosis method capable of multi-level bidirectional traceability and precise location is needed. Summary of the Invention

[0004] This application provides a multi-level fault diagnosis method and system for communication systems. By constructing a three-layer node set of physical layer, relay section, and multiplex section and a vertical directed edge representing the fault propagation relationship between layers, a cross-layer fault propagation model is established. Based on the bottom-up correlation analysis of the physical layer aging and the frequency change trend of relay section frame out-of-synchronization events, and the top-down step-by-step tracing mechanism of multiplex section B2 bit error distribution characteristics and physical layer optical power fluctuation characteristics, this technical solution solves the technical problems in existing communication system fault diagnosis caused by the independent acquisition of parameters between layers and the lack of bidirectional correlation analysis, resulting in alarm storms and difficulty in accurately locating the fault cause to a single plug-in board. It achieves the technical effects of reducing redundant alarm interference, improving fault location accuracy and efficiency, and transitioning from passive alarm response to proactive preventive maintenance.

[0005] To achieve the above objectives, the present invention provides a multi-level fault diagnosis method for communication systems, comprising: Establish a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship; In the physical layer, the laser bias current and optical power analog quantities are collected in real time. In the relay section, the frame out-of-synchronization event and B1 error statistics are collected. In the multiplexing section, the B2 error and block error count are collected. When the laser bias current of the physical layer node is detected to exceed the preset aging threshold, the frequency change trend of the associated relay node frame out-of-synchronization event is retrieved within the preset time window. When the bit error rate of the multiplex section node B2 exceeds the preset threshold, the bit error distribution characteristics of the associated relay section node B1 are traced downwards, and the optical power fluctuation characteristics of the physical layer node are further traced. Output the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

[0006] Furthermore, a three-layer node set is established, comprising the physical layer, relay segment, and multiplexing segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship, specifically including: The physical layer node set includes at least a laser bias current monitoring node, a transmit optical power monitoring node, and a receive optical power monitoring node. The relay segment node set includes at least frame out-of-synchrony event nodes, frame loss event nodes, and B1 byte bit error rate nodes; The multiplex segment node set includes at least B2 byte error count nodes, error block second nodes, critical error block second nodes, and external event alarm nodes; The longitudinal directed edges include: a first type of directed edge pointing from a physical layer node to a relay segment node, used to characterize the causal relationship between physical layer performance degradation and relay segment frame synchronization state; The second type of directed edges from relay segment nodes to multiplex segment nodes are used to characterize the causal relationship between relay segment transmission quality degradation and multiplex segment bit error rate performance. In addition, there is a third type of directed edge from external event alarm nodes to physical layer nodes, which is used to characterize the impact of environmental anomalies on the performance of physical layer devices.

[0007] Furthermore, the real-time acquisition of analog quantities of laser bias current and optical power at the physical layer specifically includes: The analog quantities of laser bias current and optical power are converted into digital quantities with a precision of more than 12 bits using an analog-to-digital converter. The continuously acquired sampled values ​​are subjected to moving average filtering to obtain the filtered current value and optical power value; The bias current deviation index is obtained by performing a differential calculation between the filtered current value and the preset initial bias current baseline of the laser. The filtered optical power value is compared with the preset normal optical power range to obtain the optical power attenuation amount and attenuation rate index. The bias current deviation index and optical power attenuation index replace the original acquired values ​​in subsequent fault diagnosis and are used to trigger the detection that the laser bias current exceeds the preset aging threshold.

[0008] Furthermore, the preset initial bias current baseline for the laser specifically includes: Read the nominal bias current value stored in the laser's built-in memory at the time of manufacture, and use it as the initial bias current baseline of the laser; After the device is powered on for the first time and its operation is stable, a baseline learning window of no more than 24 hours is entered. All valid sampled values ​​of the laser bias current are collected during this window. After removing outliers that exceed the preset range, the arithmetic mean is calculated as the initial bias current baseline of the laser. After each replacement of the laser insert or optical module, the baseline is automatically relearned, the stable operating parameters of the new device are updated to the current baseline, and the baseline version number and effective timestamp are recorded. The calibration values ​​input by maintenance personnel are received through the network management interface and used as the initial bias current baseline. This is marked as manual setting mode, in which the automatic baseline update function is disabled.

[0009] Furthermore, the filtered optical power value is compared with a preset normal optical power range, specifically including: The transmitted optical power and received optical power are compared independently. The normal range of the transmitted optical power is set with upper and lower floating thresholds based on the factory nominal value read from the optical module register. The normal range of the received optical power is set with engineering margin added based on the sensitivity and overload point values ​​read from the optical module diagnostic information. When the transmitted optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a transmission abnormality; when the received optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a reception abnormality. The attenuation rate is calculated by comparing the current optical power with historical values ​​at fixed intervals. An early warning is triggered when the attenuation rate exceeds a preset threshold for three consecutive cycles.

[0010] Furthermore, the frequency trend of frame out-of-sync events of associated relay segment nodes is retrieved within a preset time window, specifically including: When the laser bias current exceeds the preset aging threshold for three consecutive acquisition cycles, aging detection is triggered, and a time window of preset length is determined by backtracking backward from the current moment. Within the time window, retrieve the frame out-of-sync event records of relay nodes associated with the physical layer node, and count the total number of events and the frequency of occurrence in each sub-time period; The frame synchronization frequency of each sub-time period within the time window is compared in chronological order. When the frequency increases over time and coincides with the time point when the bias current exceeds the threshold, it is determined that physical layer aging has affected the frame synchronization of the relay segment.

[0011] Furthermore, when the bit error rate of multiplex section node B2 exceeds a preset threshold, the bit error distribution characteristics of the associated relay section node B1 are traced downwards, specifically including: When the B2 error exceeds the preset threshold for three consecutive collection cycles, a downward tracing is triggered. Within the traceback time window, retrieve the B1 error statistics of the associated relay segment nodes and extract the error distribution characteristics; When the B1 error distribution characteristics cannot determine the cause of the fault, the optical power values ​​of the associated physical layer nodes are further traced to extract the optical power fluctuation characteristics. The B1 error distribution characteristics are correlated with the optical power fluctuation characteristics, and the fault type is output based on the correlation analysis results.

[0012] Furthermore, a correlation analysis was conducted between the B1 bit error distribution characteristics and the optical power fluctuation characteristics, specifically including: The traceability time window is divided into six sub-time periods. The number of B1 errors in each sub-time period is counted. The maximum value is divided by the minimum value to obtain the uniformity coefficient. When the uniformity coefficient is less than three, it is determined that the B1 error distribution is uniform. Calculate the variance of optical power values ​​for all acquisition cycles within the traceability time window. When the variance is less than a preset threshold, the optical power is considered stable. The B1 bit error value and optical power value of each acquisition cycle are taken as two sequences, and the correlation between the two is calculated using the Pearson correlation coefficient formula. When the correlation coefficient is positive and greater than 0.6, the two are determined to be positively correlated. The optical power values ​​within the traceback time window are arranged in chronological order. The least squares method is used to fit a straight line and calculate the slope. When the slope is negative and the absolute value of the slope is greater than the preset attenuation threshold, it is determined that the optical power is showing a slow decreasing trend.

[0013] Furthermore, the system outputs the fault type, fault occurrence time, fault location information for the individual circuit board, and fault confidence level, specifically including: Based on the results of cross-level tracing, the fault types are divided into four categories: laser aging fault, optical module failure fault, fiber optic link fault, and line receiver fault, and output in the form of Chinese labels. The time when the fault is triggered for detection is taken as the fault occurrence time, in the format of year-month-day-hour-minute-second, accurate to the second. Output the specific slot number, board serial number, and network element IP address of the board to which the fault is located; The confidence level is calculated based on the degree of matching of each judgment indicator in the association analysis and output as a percentage. The higher the temporal agreement between the bias current exceeding the threshold and the increasing frequency of frame out-of-sync events, and the closer the Pearson correlation coefficient between B1 bit error and optical power fluctuation is to positive one, the higher the confidence level.

[0014] To achieve the above objectives, the present invention also provides a multi-level fault diagnosis system for a communication system, comprising: The fault modeling module establishes a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a vertical directed edge representing the fault propagation relationship between layers. The multi-level acquisition module acquires the laser bias current and optical power analog quantities in real time at the physical layer, acquires frame out-of-synchronization events and B1 error statistics in the relay section, and acquires B2 error and error block second count in the multiplexing section. The upward diagnostic module detects that when the laser bias current of a physical layer node exceeds a preset aging threshold, it retrieves the frequency change trend of the associated relay node frame out-of-synchronization events within a preset time window. The downward tracing module, when it detects that the bit error rate of the multiplex section node B2 exceeds the preset threshold, traces down the bit error distribution characteristics of the associated relay section node B1, and further traces the optical power fluctuation characteristics of the physical layer node. The results output module outputs the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: by constructing a three-layer node set of physical layer, relay section, and multiplexing section, and a vertical directed edge, a cross-layer fault propagation model is established, and based on a bottom-up and top-down bidirectional tracing mechanism, the cause of the fault is accurately located to the level of a single plug-in board, improving fault location efficiency; by establishing a causal relationship between the cause of the fault and the derived alarms, alarm storms are effectively suppressed; by analyzing the correlation trend of laser aging, a transition from passive alarms to proactive preventive maintenance is achieved; and by introducing external event alarm nodes, false alarms caused by environmental interference are effectively filtered out. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating a multi-level fault diagnosis method for a communication system according to an embodiment of the present invention is shown.

[0017] Figure 2A schematic diagram of a multi-level fault diagnosis system for a communication system is shown in an embodiment of the present invention. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] The following is a description of preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0023] like Figure 1 As shown, an embodiment of the present invention discloses a multi-level fault diagnosis method for a communication system, comprising: S110: Establish a three-layer node set consisting of the physical layer, relay segment, and multiplex segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship; In this embodiment, a three-layer node set is established, comprising the physical layer, relay segment, and multiplexing segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship, specifically including: The physical layer node set includes at least a laser bias current monitoring node, a transmit optical power monitoring node, and a receive optical power monitoring node. The relay segment node set includes at least frame out-of-synchrony event nodes, frame loss event nodes, and B1 byte bit error rate nodes; The multiplex segment node set includes at least B2 byte error count nodes, error block second nodes, critical error block second nodes, and external event alarm nodes; The longitudinal directed edges include: a first type of directed edge pointing from a physical layer node to a relay segment node, used to characterize the causal relationship between physical layer performance degradation and relay segment frame synchronization state; The second type of directed edges from relay segment nodes to multiplex segment nodes are used to characterize the causal relationship between relay segment transmission quality degradation and multiplex segment bit error rate performance. In addition, there is a third type of directed edge from external event alarm nodes to physical layer nodes, which is used to characterize the impact of environmental anomalies on the performance of physical layer devices.

[0024] In this embodiment, the external event alarm nodes include at least the following types: environmental temperature and humidity nodes, specifically including air conditioning failure alarm nodes, excessively high computer room temperature alarm nodes, and excessively high computer room humidity alarm nodes; power supply nodes, specifically including power fluctuation alarm nodes and abnormal voltage alarm nodes; and security nodes, specifically including access control abnormality alarm nodes and fire alarm pre-warning nodes. When the third type of directed edge is activated, the system obtains the trigger time and duration of the external event alarm node and compares it with the time window of the physical layer node anomaly. If the two times highly overlap and the magnitude of the physical layer anomaly matches the degree of environmental impact, it is determined that the current physical layer anomaly is caused by environmental factors. The system automatically suppresses the resulting relay segment frame out-of-synchronization alarm and multiplex segment B2 bit error alarm, and marks it as "caused by environmental interference" when outputting the alarm.

[0025] The beneficial effects of the above technical solution are: by introducing external event alarm nodes and establishing third-type directed edges pointing to physical layer nodes, the effective distinction between environmental interference and equipment faults is realized, thereby improving the accuracy and reliability of fault diagnosis.

[0026] S120: Real-time acquisition of laser bias current and optical power analog quantities at the physical layer; acquisition of frame out-of-synchronization events and B1 error statistics at the relay section; acquisition of B2 error and block error count at the multiplexing section. In this embodiment, the real-time acquisition of analog quantities of laser bias current and optical power at the physical layer specifically includes: The analog quantities of laser bias current and optical power are converted into digital quantities with a precision of more than 12 bits using an analog-to-digital converter. The continuously acquired sampled values ​​are subjected to moving average filtering to obtain the filtered current value and optical power value; The bias current deviation index is obtained by performing a differential calculation between the filtered current value and the preset initial bias current baseline of the laser. The filtered optical power value is compared with the preset normal optical power range to obtain the optical power attenuation amount and attenuation rate index. The bias current deviation index and optical power attenuation index replace the original acquired values ​​in subsequent fault diagnosis and are used to trigger the detection that the laser bias current exceeds the preset aging threshold.

[0027] In this embodiment, the preset initial bias current baseline for the laser specifically includes: Read the nominal bias current value stored in the laser's built-in memory at the time of manufacture, and use it as the initial bias current baseline of the laser; After the device is powered on for the first time and its operation is stable, a baseline learning window of no more than 24 hours is entered. All valid sampled values ​​of the laser bias current are collected during this window. After removing outliers that exceed the preset range, the arithmetic mean is calculated as the initial bias current baseline of the laser. After each replacement of the laser insert or optical module, the baseline is automatically relearned, the stable operating parameters of the new device are updated to the current baseline, and the baseline version number and effective timestamp are recorded. The calibration values ​​input by maintenance personnel are received through the network management interface and used as the initial bias current baseline. This is marked as manual setting mode, in which the automatic baseline update function is disabled.

[0028] In this embodiment, the filtered optical power value is compared with a preset normal optical power range, specifically including: The transmitted optical power and received optical power are compared independently. The normal range of the transmitted optical power is set with upper and lower floating thresholds based on the factory nominal value read from the optical module register. The normal range of the received optical power is set with engineering margin added based on the sensitivity and overload point values ​​read from the optical module diagnostic information. When the transmitted optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a transmission abnormality; when the received optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a reception abnormality. The attenuation rate is calculated by comparing the current optical power with historical values ​​at fixed intervals. An early warning is triggered when the attenuation rate exceeds a preset threshold for three consecutive cycles.

[0029] In this embodiment, the moving average filtering process specifically involves: for each new sampled value, forming a 5-point sampling window with the previously collected 4 consecutive sampled values, and calculating the arithmetic mean of the 5 sampled values ​​within this window as the filtered output value at the current moment. When the number of samples is less than 5, the average value is calculated based on the actual number of samples collected. The size of the filtering window can be dynamically adjusted according to the sampling rate; the higher the sampling rate, the larger the window size.

[0030] In this embodiment, the data acquisition cycle of the relay section is 1 second. Within each acquisition cycle, the number of frame synchronization failure events and their duration are counted, along with the number of B1 byte errors. Frame synchronization failure events are recorded with their occurrence and recovery times triggered by events. B1 errors are reported as cumulative values ​​on a second-by-second basis. The data acquisition cycle of the multiplex section is 1 second. Within each acquisition cycle, the total number of B2 byte errors is counted. When the B2 error rate exceeds a preset error threshold for three consecutive acquisition cycles, a downward tracing process is triggered. The data acquired by the physical layer, relay section, and multiplex section all include a unified timestamp and are aggregated to the network management center via an embedded control channel, forming a time-synchronized fault feature vector sequence.

[0031] The beneficial effects of the above technical solution are as follows: By processing the physical layer analog quantities through high-precision analog-to-digital conversion and moving average filtering, and combining factory calibration, self-learning and other methods to determine the laser baseline, and introducing continuous period judgment and attenuation rate warning mechanisms, the misjudgment caused by instantaneous fluctuations and individual differences is effectively filtered out; by synchronously collecting data from the three layers and unifying the timestamps, a time-aligned fault feature vector sequence is formed, which provides a high-quality data foundation for cross-layer correlation analysis and significantly improves the accuracy and real-time performance of fault diagnosis.

[0032] S130: When the laser bias current of the physical layer node is detected to exceed the preset aging threshold, the frequency change trend of the associated relay node frame out-of-sync event is retrieved within the preset time window. In this embodiment, retrieving the frequency change trend of associated relay segment node frame synchronization events within a preset time window specifically includes: When the laser bias current exceeds the preset aging threshold for three consecutive acquisition cycles, aging detection is triggered, and a time window of preset length is determined by backtracking backward from the current moment. Within the time window, retrieve the frame out-of-sync event records of relay nodes associated with the physical layer node, and count the total number of events and the frequency of occurrence in each sub-time period; The frame synchronization frequency of each sub-time period within the time window is compared in chronological order. When the frequency increases over time and coincides with the time point when the bias current exceeds the threshold, it is determined that physical layer aging has affected the frame synchronization of the relay segment.

[0033] In this embodiment, the preset time window is determined by retrospectively counting backwards from the current detection time. The length of the time window is related to the laser aging rate; the faster the aging rate, the shorter the time window. The time window is divided into a preset number of sub-time periods, and the frequency of frame synchronization failure events in each sub-time period is counted. The frame synchronization failure frequencies of each sub-time period are arranged in chronological order. When the frequency of multiple consecutive sub-time periods is higher than that of the previous sub-time period, it is determined that the frequency is increasing. The moment when the bias current first exceeds the aging threshold and the moment when the frame synchronization failure frequency begins to increase are recorded. If the time difference between the two does not exceed the set proportion of the time window length, it is determined that the time points coincide. When the frequency shows an increasing trend and coincides with the moment when the bias current exceeds the threshold, the system determines that the physical layer laser aging has had a substantial impact on the relay segment frame synchronization and outputs a successful association matching indicator.

[0034] The beneficial effects of the above technical solution are: by dynamically linking the time window length with the aging rate, statistically analyzing the frequency of sub-time periods, determining the continuous increasing trend, and comparing the time point coincidence, a quantitative causal analysis of physical layer aging and relay segment frame out-of-sync is realized, effectively avoiding misjudgment and providing a reliable basis for fault propagation chain location and proactive maintenance.

[0035] S140: When the bit error rate of the multiplex section node B2 exceeds the preset threshold, trace down the bit error distribution characteristics of the associated relay section node B1, and further trace the optical power fluctuation characteristics of the physical layer node. In this embodiment, when the bit error rate of multiplex segment node B2 exceeds a preset threshold, the bit error distribution characteristics of the associated relay segment node B1 are traced downwards, specifically including: When the B2 error exceeds the preset threshold for three consecutive collection cycles, a downward tracing is triggered. Within the traceback time window, retrieve the B1 error statistics of the associated relay segment nodes and extract the error distribution characteristics; When the B1 error distribution characteristics cannot determine the cause of the fault, the optical power values ​​of the associated physical layer nodes are further traced to extract the optical power fluctuation characteristics. The B1 error distribution characteristics are correlated with the optical power fluctuation characteristics, and the fault type is output based on the correlation analysis results.

[0036] In this embodiment, the correlation analysis between the B1 bit error distribution characteristics and the optical power fluctuation characteristics is performed, specifically including: The traceability time window is divided into six sub-time periods. The number of B1 errors in each sub-time period is counted. The maximum value is divided by the minimum value to obtain the uniformity coefficient. When the uniformity coefficient is less than three, it is determined that the B1 error distribution is uniform. Calculate the variance of optical power values ​​for all acquisition cycles within the traceability time window. When the variance is less than a preset threshold, the optical power is considered stable. The B1 bit error value and optical power value of each acquisition cycle are taken as two sequences, and the correlation between the two is calculated using the Pearson correlation coefficient formula. When the correlation coefficient is positive and greater than 0.6, the two are determined to be positively correlated. The optical power values ​​within the traceback time window are arranged in chronological order. The least squares method is used to fit a straight line and calculate the slope. When the slope is negative and the absolute value of the slope is greater than the preset attenuation threshold, it is determined that the optical power is showing a slow decreasing trend.

[0037] In this embodiment, the length of the tracing time window is related to the duration and severity of B2 bit errors. The more severe the bit errors, the shorter the time window, in order to improve response sensitivity. The tracing time window can also be manually configured by the network management system. When the B1 bit error distribution is uniform but the optical power variance is near the preset threshold boundary and cannot be clearly determined, or when the B1 bit error distribution is uneven but all indicators have not reached the determination threshold, it is considered that the root cause cannot be determined. At this time, further tracing of the physical layer optical power fluctuation characteristics is performed for supplementary analysis.

[0038] In this embodiment, the corresponding fault type is output based on the correlation analysis results: when the B1 bit error distribution is uniform and the optical power is stable, the output line receiver is faulty; when the B1 bit error is positively correlated with the optical power fluctuation, the output optical module or fiber optic link is faulty; when the B1 bit error distribution is uniform and the optical power shows a slow decreasing trend, the output laser aging fault is present.

[0039] The beneficial effects of the above technical solution are: by triggering downward tracing through B2 error, extracting quantitative indicators such as B1 error uniformity coefficient, optical power variance, correlation coefficient and attenuation slope, establishing a step-by-step root cause tracing mechanism, and automatically outputting corresponding types such as line receiver fault, optical module or fiber fault, laser aging fault according to different characteristic combinations, thus realizing accurate location and automated output of cross-layer faults.

[0040] S150: Outputs the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

[0041] In this embodiment, the output includes the fault type, fault occurrence time, single-board identification information to which the fault is located, and fault confidence level, specifically including: Based on the results of cross-level tracing, the fault types are divided into four categories: laser aging fault, optical module failure fault, fiber optic link fault, and line receiver fault, and output in the form of Chinese labels. The time when the fault is triggered for detection is taken as the fault occurrence time, in the format of year-month-day-hour-minute-second, accurate to the second. Output the specific slot number, board serial number, and network element IP address of the board to which the fault is located; The confidence level is calculated based on the degree of matching of each judgment indicator in the association analysis and output as a percentage. The higher the degree of temporal agreement between the bias current exceeding the threshold and the increasing frequency of frame out-of-sync events, and the closer the Pearson correlation coefficient between B1 bit error and optical power fluctuation is to 1, the higher the confidence level.

[0042] To further illustrate the technical concept of this invention, the technical solution of this invention will now be described in conjunction with specific application scenarios.

[0043] Correspondingly, such as Figure 2 As shown, this application also provides a multi-level fault diagnosis system for communication systems, including: The fault modeling module establishes a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a vertical directed edge representing the fault propagation relationship between layers. The multi-level acquisition module acquires the laser bias current and optical power analog quantities in real time at the physical layer, acquires frame out-of-synchronization events and B1 error statistics in the relay section, and acquires B2 error and error block second count in the multiplexing section. The upward diagnostic module detects that when the laser bias current of a physical layer node exceeds a preset aging threshold, it retrieves the frequency change trend of the associated relay node frame out-of-synchronization events within a preset time window. The downward tracing module, when it detects that the bit error rate of the multiplex section node B2 exceeds the preset threshold, traces down the bit error distribution characteristics of the associated relay section node B1, and further traces the optical power fluctuation characteristics of the physical layer node. The results output module outputs the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

[0044] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0045] Although the invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The fact that not all of these combinations are described in this specification is merely for the sake of brevity and resource conservation.

[0046] It will be understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-level fault diagnosis method for communication systems, characterized in that, include: Establish a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship; In the physical layer, the laser bias current and optical power analog quantities are collected in real time. In the relay section, the frame out-of-synchronization event and B1 error statistics are collected. In the multiplexing section, the B2 error and block error count are collected. When the laser bias current of the physical layer node is detected to exceed the preset aging threshold, the frequency change trend of the associated relay node frame out-of-synchronization event is retrieved within the preset time window. When the bit error rate of the multiplex section node B2 exceeds the preset threshold, the bit error distribution characteristics of the associated relay section node B1 are traced downwards, and the optical power fluctuation characteristics of the physical layer node are further traced. Output the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

2. The multi-level fault diagnosis method for a communication system according to claim 1, characterized in that, Establish a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a longitudinal directed edge representing the inter-layer fault propagation relationship, specifically including: The physical layer node set includes at least a laser bias current monitoring node, a transmit optical power monitoring node, and a receive optical power monitoring node. The relay segment node set includes at least frame out-of-synchrony event nodes, frame loss event nodes, and B1 byte bit error rate nodes; The multiplex segment node set includes at least B2 byte error count nodes, error block second nodes, critical error block second nodes, and external event alarm nodes; The longitudinal directed edges include: a first type of directed edge pointing from a physical layer node to a relay segment node, used to characterize the causal relationship between physical layer performance degradation and relay segment frame synchronization state; The second type of directed edges from relay segment nodes to multiplex segment nodes are used to characterize the causal relationship between relay segment transmission quality degradation and multiplex segment bit error rate performance. In addition, there is a third type of directed edge from external event alarm nodes to physical layer nodes, which is used to characterize the impact of environmental anomalies on the performance of physical layer devices.

3. The multi-level fault diagnosis method for a communication system according to claim 1, characterized in that, The real-time acquisition of analog quantities of laser bias current and optical power at the physical layer specifically includes: The analog quantities of laser bias current and optical power are converted into digital quantities with a precision of more than 12 bits using an analog-to-digital converter. The continuously acquired sampled values ​​are subjected to moving average filtering to obtain the filtered current value and optical power value; The bias current deviation index is obtained by performing a differential calculation between the filtered current value and the preset initial bias current baseline of the laser. The filtered optical power value is compared with the preset normal optical power range to obtain the optical power attenuation amount and attenuation rate index. The bias current deviation index and optical power attenuation index replace the original acquired values ​​in subsequent fault diagnosis and are used to trigger the detection that the laser bias current exceeds the preset aging threshold.

4. The multi-level fault diagnosis method for a communication system according to claim 3, characterized in that, The preset initial bias current baseline for the laser includes: Read the nominal bias current value stored in the laser's built-in memory at the time of manufacture, and use it as the initial bias current baseline of the laser; After the device is powered on for the first time and its operation is stable, a baseline learning window of no more than 24 hours is entered. All valid sampled values ​​of the laser bias current are collected during this window. After removing outliers that exceed the preset range, the arithmetic mean is calculated as the initial bias current baseline of the laser. After each replacement of the laser insert or optical module, the baseline is automatically relearned, the stable operating parameters of the new device are updated to the current baseline, and the baseline version number and effective timestamp are recorded. The calibration values ​​input by maintenance personnel are received through the network management interface and used as the initial bias current baseline. This is marked as manual setting mode, in which the automatic baseline update function is disabled.

5. A multi-level fault diagnosis method for a communication system according to claim 3, characterized in that, The filtered optical power value is compared with the preset normal optical power range, specifically including: The transmitted optical power and received optical power are compared independently. The normal range of the transmitted optical power is set with upper and lower floating thresholds based on the factory nominal value read from the optical module register. The normal range of the received optical power is set with engineering margin added based on the sensitivity and overload point values ​​read from the optical module diagnostic information. When the transmitted optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a transmission abnormality; when the received optical power value exceeds the normal range for three consecutive acquisition cycles, it is determined to be a reception abnormality. The attenuation rate is calculated by comparing the current optical power with historical values ​​at fixed intervals. An early warning is triggered when the attenuation rate exceeds a preset threshold for three consecutive cycles.

6. The multi-level fault diagnosis method for a communication system according to claim 1, characterized in that, The frequency trend of frame out-of-sync events of associated relay segment nodes is retrieved within a preset time window, specifically including: When the laser bias current exceeds the preset aging threshold for three consecutive acquisition cycles, aging detection is triggered, and a time window of preset length is determined by backtracking backward from the current moment. Within the time window, retrieve the frame out-of-sync event records of relay nodes associated with the physical layer node, and count the total number of events and the frequency of occurrence in each sub-time period; The frame synchronization frequency of each sub-time period within the time window is compared in chronological order. When the frequency increases over time and coincides with the time point when the bias current exceeds the threshold, it is determined that physical layer aging has affected the frame synchronization of the relay segment.

7. The multi-level fault diagnosis method for a communication system according to claim 1, characterized in that, When the bit error rate of multiplex section node B2 exceeds a preset threshold, the bit error distribution characteristics of the associated relay section node B1 are traced downwards, specifically including: When the B2 error exceeds the preset threshold for three consecutive collection cycles, a downward tracing is triggered. Within the traceback time window, retrieve the B1 error statistics of the associated relay segment nodes and extract the error distribution characteristics; When the B1 error distribution characteristics cannot determine the cause of the fault, the optical power values ​​of the associated physical layer nodes are further traced to extract the optical power fluctuation characteristics. The B1 error distribution characteristics are correlated with the optical power fluctuation characteristics, and the fault type is output based on the correlation analysis results.

8. A multi-level fault diagnosis method for a communication system according to claim 7, characterized in that, The correlation analysis between the B1 bit error distribution characteristics and the optical power fluctuation characteristics includes: The traceability time window is divided into six sub-time periods. The number of B1 errors in each sub-time period is counted. The maximum value is divided by the minimum value to obtain the uniformity coefficient. When the uniformity coefficient is less than three, it is determined that the B1 error distribution is uniform. Calculate the variance of optical power values ​​for all acquisition cycles within the traceability time window. When the variance is less than a preset threshold, the optical power is considered stable. The B1 bit error value and optical power value of each acquisition cycle are taken as two sequences, and the correlation between the two is calculated using the Pearson correlation coefficient formula. When the correlation coefficient is positive and greater than 0.6, the two are determined to be positively correlated. The optical power values ​​within the traceback time window are arranged in chronological order. The least squares method is used to fit a straight line and calculate the slope. When the slope is negative and the absolute value of the slope is greater than the preset attenuation threshold, it is determined that the optical power is showing a slow decreasing trend.

9. A multi-level fault diagnosis method for a communication system according to claim 1, characterized in that, Output the fault type, fault occurrence time, single-board identification information to which the fault was located, and fault confidence level, specifically including: Based on the results of cross-level tracing, the fault types are divided into four categories: laser aging fault, optical module failure fault, fiber optic link fault, and line receiver fault, and output in the form of Chinese labels. The time when the fault is triggered for detection is taken as the fault occurrence time, in the format of year-month-day-hour-minute-second, accurate to the second. Output the specific slot number, board serial number, and network element IP address of the board to which the fault is located; The confidence level is calculated based on the degree of matching of each judgment indicator in the association analysis and output as a percentage. The higher the temporal agreement between the bias current exceeding the threshold and the increasing frequency of frame out-of-sync events, and the closer the Pearson correlation coefficient between B1 bit error and optical power fluctuation is to positive one, the higher the confidence level.

10. A multi-level fault diagnosis system for a communication system, applied to the multi-level fault diagnosis method for a communication system as described in any one of claims 1-9, characterized in that, include: The fault modeling module establishes a three-layer node set consisting of the physical layer, relay segment, and multiplexing segment, as well as a vertical directed edge representing the fault propagation relationship between layers. The multi-level acquisition module acquires the laser bias current and optical power analog quantities in real time at the physical layer, acquires frame out-of-synchronization events and B1 error statistics in the relay section, and acquires B2 error and error block second count in the multiplexing section. The upward diagnostic module detects that when the laser bias current of a physical layer node exceeds a preset aging threshold, it retrieves the frequency change trend of the associated relay node frame out-of-synchronization events within a preset time window. The downward tracing module, when it detects that the bit error rate of the multiplex section node B2 exceeds the preset threshold, traces down the bit error distribution characteristics of the associated relay section node B1, and further traces the optical power fluctuation characteristics of the physical layer node. The results output module outputs the fault type, fault occurrence time, fault location information of the single plug-in board, and fault confidence level.

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