Communication optical cable line fault rapid positioning system

Abstract

The invention discloses a communication optical cable line fault rapid positioning system, which comprises optical time domain reflectometers and a remote monitoring center, and is characterized in that two optical time domain reflectometers with different optical pulse wavelengths are respectively connected to two ends of a communication optical cable line through wavelength division multiplexers on corresponding sides; the optical time domain reflectometer analyzes a reflected light signal received by the optical time domain reflectometer through a built-in intelligent algorithm, quickly calculates the position of a fault point and judges the type of the fault; the intelligent algorithm comprises a loss positioning algorithm, a reflection peak identification algorithm and a microbend loss analysis algorithm; the loss positioning algorithm is used for detecting the position of a fault point and distinguishing an optical fiber breakpoint and a loss type fault; the reflection peak recognition algorithm is used for detecting a fault point position; the microbend loss analysis algorithm is used for detecting and distinguishing microbend loss and other types of loss; the system has the advantages of being stable in detection system, good in detection effect, rapid in fault positioning and more accurate in detection result, and automatic detection, remote detection and remote monitoring and management of optical cable faults can be conveniently achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of optical cable fault locating, and in particular relates to a communication optical cable line fault rapid locating system. Background Art

[0002] Communication optical cable is a transmission medium similar to communication. It is mainly composed of optical fiber, reinforcement layer and outer sheath. Optical fiber is the core part of completing communication work. It transmits optical signals through total reflection of light in optical fiber to achieve long-distance transmission of information. It has the advantages of large transmission bandwidth, high communication capacity, low loss and strong anti-interference ability. It is widely used in long-distance communication, metropolitan area network, access network and other communication systems.

[0003] A communication optical cable line fault refers to an abnormal situation in the process of transmitting information on the optical cable line, which is manifested as communication signal interruption, severe signal attenuation, increased transmission error rate, etc. For communication optical cable line faults, the existing fault point detection and positioning technology generally arranges staff to carry an optical time domain reflectometer (OTDR) to one end of the faulty optical cable line on site after the fault occurs, and uses OTDR to unidirectionally test the faulty optical cable to locate the position of the fault point, or uses OTDR+GIS technology to locate the position of the fault point. There are problems such as slow response speed, low fault handling efficiency, and low fault point positioning accuracy. In order to solve the above problems, it is necessary to develop a communication optical cable line fault rapid positioning system. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a communication optical cable line fault rapid location system with a stable detection system, good detection effect, fast fault location and more accurate detection results, so as to facilitate the automatic detection and remote detection of optical cable faults as well as remote monitoring and management.

[0005] The object of the present invention is achieved as follows: a communication optical cable line fault rapid location system, including an optical time domain reflectometer and a remote monitoring center, two optical time domain reflectometers with different optical pulse wavelengths are respectively connected to the two ends of the communication optical cable line through wavelength division multiplexers on the corresponding sides, and the optical time domain reflectometer analyzes the reflected light signal received by it through a built-in intelligent algorithm to quickly calculate the fault point location and determine the fault type; the intelligent algorithm includes a loss location algorithm, a reflection peak recognition algorithm and a microbend loss analysis algorithm; the loss location algorithm is used to detect the fault point location and distinguish between optical fiber breakpoints and loss-type faults; the reflection peak recognition algorithm is used to detect the fault point location; the microbend loss analysis algorithm is used to detect and distinguish between microbend loss and other types of loss;

[0006] The two optical time domain reflectometers communicate with the remote monitoring center through built-in wireless communication modules respectively. The two optical time domain reflectometers send their own detection results to the remote monitoring center respectively. The remote monitoring center compares and analyzes the two detection results with close reception time. When it is found that at least one of the detection results is a fault result, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect until both detection results are fault results. Then, an average value is taken for the fault point positions of the two detection results, and it is determined whether the fault types of the two detection results are the same. When it is found that the two detection results are of different fault types, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect once.

[0007] Preferably, the two optical time domain reflectometers can perform automatic fault detection on the communication optical cable line between the two regularly or irregularly under the control of the remote monitoring center.

[0008] Preferably, both of the two optical time domain reflectometers are equipped with a built-in clock module and a clock trigger module, and the two optical time domain reflectometers can periodically or irregularly perform automatic fault detection on the communication optical cable line between them through their built-in synchronous clock modules.

[0009] Preferably, according to the principle of optical time domain reflection, when an optical pulse encounters a breakpoint or a loss point during transmission in an optical fiber, the reflected light power will change, and the loss location algorithm determines the loss location by comparing the power difference between the transmitted optical pulse and the reflected optical pulse;

[0010] Specifically, in the normal part of the optical fiber, the reflected light power is relatively stable. When there is a breakpoint or loss in the optical fiber, the reflected light power will suddenly drop. When the reflected light power drops sharply or even almost to zero, it is judged as a breakpoint fault. When it drops gently, it is judged as a loss-type fault. The fault point is located by calculating the position where the reflected light power changes. The calculation formula is as follows:

[0011]

[0012] Wherein, L1 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, c is the speed of light in a vacuum, t1 is the time difference from the emission of the light pulse to the reception of the reflected light, which is specifically determined by comparing the power difference between the emitted light pulse and the reflected light pulse, and n is the refractive index of the optical fiber.

[0013] Preferably, according to the Fresnel reflection principle, when a breakpoint or end face appears in the optical fiber, a strong Fresnel reflection will be generated, which is manifested as an obvious reflection peak on the optical time domain reflection curve. The reflection peak recognition algorithm is to perform peak value detection on the optical time domain reflection curve to identify and determine the reflection peak position as the fault point position;

[0014] Specifically, the reflection peak recognition algorithm pre-sets a threshold value. When the intensity of the detected reflection peak exceeds the threshold value, the position of the reflection peak is determined to be the fault point position. The calculation formula is as follows:

[0015]

[0016] Wherein, L2 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, c is the speed of light in a vacuum, t2 is the time difference from the emission of the light pulse to the reception of the reflected light, specifically, the time from the emission of the light pulse to the detection of the reflection peak, and n is the refractive index of the optical fiber.

[0017] Preferably, in the peak detection process, a derivation method or a local maximum search is adopted.

[0018] Preferably, the loss increase area in the optical time domain reflection curve is analyzed, and whether it is microbend loss is determined by theoretical analysis of the mode of optical signal transmission in the optical fiber and the actual measured optical power loss change;

[0019] Specifically, the microbend loss analysis algorithm analyzes the loss slope change characteristics in the optical time domain reflection curve based on the consideration of the core diameter and refractive index physical properties of the optical fiber. When the loss slope is relatively gentle, it is judged as microbend loss. When the loss slope is steeper or shows a different change trend, it is judged as other types of loss.

[0020] Preferably, the other types of losses include optical fiber breakage and poor connection. The optical fiber breakage is manifested in the optical time domain reflection curve as a sudden drop in reflected light power to near zero, and the poor connection is manifested as an obvious loss peak at the connection point.

[0021] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] (1) The present invention uses two optical time domain reflectometers with different optical pulse wavelengths to perform fault detection on the optical cable from both ends. The bidirectional detection system is stable and has good bidirectional detection effect. At the same time, the present invention uses a remote monitoring center to compare and analyze the two detection results, which can quickly locate the fault and make the detection result more accurate. The fault point location is more precise, and the fault type result is closer to the actual situation, which facilitates the timely implementation of subsequent fault handling work and the rapid repair of the faulty optical cable line.

[0023] (2) The present invention adopts a loss location algorithm, a reflection peak identification algorithm and a microbend loss analysis algorithm. The three algorithms together detect and compare the fault point location and fault type multiple times, further improving the accuracy of the detection results;

[0024] In general, the present invention has the advantages of a stable detection system, good detection effect, rapid fault location, and more accurate detection results, and is convenient for realizing automatic detection and remote detection of optical cable faults as well as remote monitoring and management. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the system composition of the present invention.

[0026] Figure 2 It is a flow chart of the detection method of the present invention.

[0027] In the figure: 1. optical time domain reflectometer 2. wavelength division multiplexer 3. communication optical cable line 4. communication optical terminal 5. remote monitoring center. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0029] like Figure 1 and Figure 2 As shown, the present invention provides a communication optical cable line fault rapid location system, including an optical time domain reflectometer 1 and a remote monitoring center 5, two optical time domain reflectometers 1 with different optical pulse wavelengths are respectively connected to the two ends of a communication optical cable line 3 through a wavelength division multiplexer 2 on the corresponding side, and a communication optical terminal 4 for realizing optical cable communication is also connected to the communication optical cable line 3 through the wavelength division multiplexer 2.

[0030] Specifically, through the wavelength division multiplexer 2 , the optical time domain reflectometer 1 can realize its new function without affecting the original communication function of the communication optical cable line 2 .

[0031] Specifically, the wavelengths of the test light pulses of the two optical time domain reflectometers 1 are different from each other, and the wavelengths of the test light pulses of the two optical time domain reflectometers 1 are different from the wavelengths of the communication light signals of the two original communication optical terminals 4 to avoid mutual interference.

[0032] Specifically, the optical time domain reflectometer 1 adds intelligent algorithms, wireless communication modules, etc. on the basis of its existing technology to facilitate the implementation of corresponding new functions.

[0033] First, the optical time domain reflectometer 1 analyzes the reflected light signal it receives through a built-in intelligent algorithm, quickly calculates the fault point location, and determines the fault type. The intelligent algorithm includes a loss location algorithm, a reflection peak recognition algorithm, and a microbend loss analysis algorithm; the loss location algorithm is used to detect the fault point location and distinguish between fiber breakpoints and loss-type faults; the reflection peak recognition algorithm is used to detect the fault point location; and the microbend loss analysis algorithm is used to detect and distinguish between microbend loss and other types of loss.

[0034] Specifically, the optical time domain reflectometer 1 normalizes the three analysis results based on the analysis results of its three built-in intelligent algorithms, normalizes the fault point positions analyzed by the loss location algorithm and the reflection peak recognition algorithm (such as taking the average value) to obtain the fault point position of the detection result, and normalizes the fault types analyzed by the loss location algorithm and the microbend loss analysis algorithm (such as combining the same type into one; different types can be reported at the same time) to obtain the fault type of the detection result.

[0035] Secondly, the two optical time domain reflectometers 1 communicate with the remote monitoring center 5 through the built-in wireless communication module. The two optical time domain reflectometers 1 send their respective detection results to the remote monitoring center 5. The remote monitoring center 5 compares and analyzes the two detection results with close reception time. When it is found that at least one of the detection results is a fault result, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect until both detection results are fault results, so as to ensure the authenticity of the fault detection results and confirm that the fault is real. Then, the average value of the fault point position of the two detection results is taken, and at the same time, it is determined whether the fault types of the two detection results are the same. When it is found that the two detection results are of different fault types, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect once. The rest of the work is handled by the staff.

[0036] Specifically, the average value of the fault point positions of the two test results is calculated as follows. In theory, the sum of the fault point positions of the two test results should be the total length of the communication optical cable line 3. Taking into account the detection error, first subtract the fault point position of one of the test results from the total length of the communication optical cable line 3, and then use this difference and the fault point position of the other test result to take the average value. This average value is the position of the optical time domain reflectometer 1 corresponding to the other test result from the fault point.

[0037] The following provides two implementation methods for the system to automatically detect faults on the communication optical cable line 3, and quickly locate the fault through remote automatic fault detection.

[0038] First, the two optical time domain reflectometers 1 can perform automatic fault detection on the communication optical cable line 3 between the two regularly or irregularly under the control of the remote monitoring center 5 .

[0039] The second type is that both of the two optical time domain reflectometers 1 have a built-in clock module and a clock trigger module. The two optical time domain reflectometers 1 can periodically or irregularly perform automatic fault detection on the communication optical cable line 3 located between them through their own built-in synchronous clock modules.

[0040] The following provides a specific implementation method for the intelligent algorithm built into the optical time domain reflectometer 1.

[0041] (1) Loss location algorithm: According to the principle of optical time domain reflectometry, when a light pulse encounters a breakpoint or loss point during transmission in an optical fiber, the reflected light power will change. The loss location algorithm determines the loss location by comparing the power difference between the transmitted light pulse and the reflected light pulse.

[0042] In the normal part of the optical fiber, the reflected light power is relatively stable. When a breakpoint or loss occurs in the optical fiber, the reflected light power will suddenly drop. When the reflected light power drops sharply or even almost to zero, it is judged as a breakpoint fault. When a moderate drop occurs (that is, the reflected light power is lower than the normal level, not as drastic as a breakpoint), it is judged as a loss-type fault.

[0043] In the principle of using optical time domain reflectometry technology for loss location, when a light pulse is transmitted in an optical fiber, under normal circumstances, the optical signal will have a certain degree of natural attenuation. When the optical fiber is bent excessively or cracks appear in the optical fiber, causing the loss to increase, the power of the reflected light pulse will change compared to normal conditions. Therefore, an optical time domain reflectometer is used to emit a light pulse of known power, and then the power of the returned reflected light pulse is detected. By comparing the difference between the two, combined with the propagation speed of light in the optical fiber, etc., the distance of the loss position in the optical fiber can be calculated, thereby locating the fault point.

[0044] The loss location algorithm locates the fault point by calculating the position where the reflected light power changes. The calculation formula is as follows:

[0045]

[0046] Where L1 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, and c is the speed of light in vacuum (usually 3×10 8 m / s), t1 is the time difference from the emission of the light pulse to the reception of the reflected light, which is determined by comparing the power difference between the emitted light pulse and the reflected light pulse, and n is the refractive index of the optical fiber (refer to the specification parameters of the optical fiber).

[0047] Through the loss location algorithm, the optical time domain reflectometer can quickly and accurately locate breakpoints and loss-type faults in optical fibers, providing an important basis for the maintenance and repair of optical fiber communication systems.

[0048] (2) Reflection peak identification algorithm: According to the Fresnel reflection principle, when a breakpoint or end face appears on an optical fiber, a strong Fresnel reflection will be generated, which will appear as an obvious reflection peak on the optical time domain reflection curve. The position of the reflection peak is the position of the fault point. The reflection peak identification algorithm detects the peak value of the optical time domain reflection curve and identifies and determines the position of the reflection peak as the fault point.

[0049] Peak detection can be performed using some mathematical methods, such as derivation method, local maximum search, etc. The derivation method is to perform first-order or second-order derivation on the optical time domain reflection curve, and the point where the derivative is zero corresponds to the peak point of the curve. The local maximum search is to search for the local maximum value within a certain window range to find the position of the reflection peak.

[0050] The reflection peak recognition algorithm pre-sets a threshold value, which can be obtained based on experience or by analyzing and statistically analyzing the optical time domain reflection curves of a large number of normal optical fibers and faulty optical fibers. When the intensity of the detected reflection peak exceeds this threshold, the position of the reflection peak is judged to be the fault point position. The calculation formula is as follows:

[0051]

[0052] Where L2 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, and c is the speed of light in vacuum (usually 3×10 8 m / s), t2 is the time difference from the emission of the light pulse to the reception of the reflected light, specifically the time from the emission of the light pulse to the detection of the reflection peak, and n is the refractive index of the optical fiber (refer to the specification parameters of the optical fiber).

[0053] In addition, in the first two, both the loss location algorithm and the reflection peak identification algorithm need to use the round-trip time of the optical pulse in the optical fiber to calculate the fault point location. The difference is: in the reflection peak identification algorithm, the appearance of the reflection peak represents that the light has been strongly reflected at the breakpoint or interface, so the time difference corresponding to the reflection peak can be used to calculate the fault point location; in the loss location algorithm, by analyzing the change in optical reflection power caused by the loss during the transmission of the optical pulse, the time difference corresponding to the change in optical reflection power can be used to calculate the fault point location. Because there may be a certain error between the two, the fault point location of the result can be obtained by taking the average of the two to eliminate certain errors.

[0054] Through the reflection peak recognition algorithm, the optical time domain reflectometer can quickly and accurately locate the breakpoint fault point in the optical cable, providing favorable support for the maintenance and repair of the optical fiber communication system.

[0055] (3) Microbend loss analysis algorithm: Microbend loss is a common type of loss in optical fiber communications. It is mainly caused by the leakage of part of the light from the core to the cladding when the optical fiber is bent at a small radius. Therefore, the loss increase area in the optical time domain reflection curve can be analyzed. Through theoretical analysis of the mode of optical signal transmission in the optical fiber and combined with the actual measured optical power loss change, it can be judged whether it is microbend loss.

[0056] When an optical fiber is subjected to external pressure or bending force, the shape of the optical fiber will change slightly, forming a small radius bend. In this case, the mode of light transmission in the optical fiber will change, and part of the light energy will leak from the core to the cladding, resulting in optical power loss, which is manifested as a gentle loss increase area in the optical time domain reflection curve.

[0057] The microbend loss algorithm analyzes the loss increase area in the optical time domain reflection curve. First, through the theoretical analysis of the mode of optical signal transmission in the optical fiber, we can understand the impact of different types of loss on the optical transmission mode. Then, combined with the actual measured optical power loss changes, we can determine whether it is microbend loss.

[0058] Specifically, the microbend loss analysis algorithm first considers the physical properties of the optical fiber, such as core diameter and refractive index, because these parameters affect the transmission characteristics of light in the optical fiber, and have different effects on different types of losses. For example, optical fibers with smaller core diameters are more susceptible to microbend losses, while optical fibers with higher refractive indices may be more sensitive to other types of losses. Then, the loss change characteristics in the optical time domain reflection curve are analyzed, such as the loss slope. For microbend losses, the loss slope is usually relatively gentle, while for other types of losses, the loss slope is steeper or presents different change trends.

[0059] Other types of losses, such as fiber breakage and poor splicing (such as the connection point of two optical fibers spliced ​​by a fiber fusion splicer may have performance degradation after long-term use). Fiber breakage is manifested in the optical time domain reflection curve as a sudden drop in reflected light power to near zero, with a relatively clear position, which is very different from the gentle increase in microbend loss. Poor splicing is manifested as an obvious loss peak at the splicing point, which is different from the gentle area of ​​microbend loss.

[0060] By comprehensively considering the physical properties of optical fiber, the characteristics of loss changes in the optical time domain reflection curve, and the characteristics of other types of losses, the microbend loss algorithm can accurately distinguish microbend losses from other types of losses, providing favorable support for fault diagnosis and maintenance of optical fiber communication systems.

[0061] Working principle: Two optical time domain reflectometers 1 start to detect the fault of the communication optical cable line 3 automatically at the same time. After the detection is completed, the detection results are sent to the remote monitoring center 5 through the built-in wireless communication module. The remote monitoring center 5 compares and analyzes the two detection results. Figure 2 After the comparative analysis is completed in the process shown, the final result is sent to the relevant staff to notify them to carry out subsequent troubleshooting work, quickly find the fault point at the given fault point location, and take corresponding repair measures for different fault types, such as fiber breakage, excessive bending, etc., such as using a fiber optic fusion splicer to fuse the broken fiber, and expand the bending radius of the fiber.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A communication optical cable line fault rapid location system, comprising an optical time domain reflectometer and a remote monitoring center, characterized in that: The two optical time domain reflectometers with different optical pulse wavelengths are connected to the two ends of the communication optical cable line through the wavelength division multiplexers on the corresponding sides. The optical time domain reflectometer analyzes the reflected light signal it receives through the built-in intelligent algorithm to quickly calculate the fault point location and determine the fault type; the intelligent algorithm includes a loss location algorithm, a reflection peak recognition algorithm and a microbend loss analysis algorithm; The loss location algorithm is used to detect the location of the fault point and distinguish between optical fiber breakpoints and loss-type faults; the reflection peak identification algorithm is used to detect the location of the fault point; the microbend loss analysis algorithm is used to detect and distinguish between microbend loss and other types of loss; The two optical time domain reflectometers communicate with the remote monitoring center through built-in wireless communication modules respectively. The two optical time domain reflectometers send their own detection results to the remote monitoring center respectively. The remote monitoring center compares and analyzes the two detection results with close reception time. When it is found that at least one of the detection results is a fault result, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect until both detection results are fault results. Then, an average value is taken for the fault point positions of the two detection results, and it is determined whether the fault types of the two detection results are the same. When it is found that the two detection results are of different fault types, an alarm is issued, and a re-detection instruction is sent to the two optical time domain reflectometers to order them to re-detect once.

2. The communication optical cable line fault rapid location system according to claim 1 is characterized by: The two optical time domain reflectometers can perform automatic fault detection on the communication optical cable line between the two regularly or irregularly under the control of the remote monitoring center.

3. The communication optical cable line fault rapid location system according to claim 1 is characterized in that: The two optical time domain reflectometers are both equipped with a clock module and a clock trigger module. The two optical time domain reflectometers can periodically or irregularly perform automatic fault detection on the communication optical cable line between them through their respective built-in synchronous clock modules.

4. The communication optical cable line fault rapid location system according to claim 1 is characterized by: According to the principle of optical time domain reflection, when an optical pulse encounters a breakpoint or loss point during transmission in an optical fiber, the reflected light power will change. The loss location algorithm determines the loss location by comparing the power difference between the transmitted optical pulse and the reflected optical pulse. Specifically, in the normal part of the optical fiber, the reflected light power is relatively stable. When there is a breakpoint or loss in the optical fiber, the reflected light power will suddenly drop. When the reflected light power drops sharply or even almost to zero, it is judged as a breakpoint fault. When it drops gently, it is judged as a loss-type fault. The fault point is located by calculating the position where the reflected light power changes. The calculation formula is as follows: Wherein, L1 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, c is the speed of light in a vacuum, t1 is the time difference from the emission of the light pulse to the reception of the reflected light, which is specifically determined by comparing the power difference between the emitted light pulse and the reflected light pulse, and n is the refractive index of the optical fiber.

5. The communication optical cable line fault rapid location system according to claim 1 is characterized by: According to the Fresnel reflection principle, when a breakpoint or end face appears in an optical fiber, a strong Fresnel reflection will be generated, which is manifested as an obvious reflection peak on the optical time domain reflection curve. The reflection peak recognition algorithm is to detect the peak value of the optical time domain reflection curve, identify and determine the reflection peak position as the fault point position; Specifically, the reflection peak recognition algorithm pre-sets a threshold value. When the intensity of the reflection peak detected exceeds the threshold value, the reflection peak position is determined to be the fault point position. The calculation formula is as follows: Wherein, L2 is the distance from the fault point to the transmitting end of the optical time domain reflectometer, c is the speed of light in a vacuum, t2 is the time difference from the emission of the light pulse to the reception of the reflected light, specifically, the time from the emission of the light pulse to the detection of the reflection peak, and n is the refractive index of the optical fiber.

6. The communication optical cable line fault rapid location system according to claim 5, characterized in that: In the peak detection process, a derivation method or a local maximum value search is adopted.

7. The communication optical cable line fault rapid location system according to claim 1, characterized in that: Analyze the loss increase area in the optical time domain reflection curve, and determine whether it is microbend loss by theoretically analyzing the mode of optical signal transmission in the optical fiber and combining the actual measured optical power loss change; Specifically, the microbend loss analysis algorithm analyzes the loss slope change characteristics in the optical time domain reflection curve based on the consideration of the core diameter and refractive index physical properties of the optical fiber. When the loss slope is relatively gentle, it is judged as microbend loss. When the loss slope is steeper or shows a different change trend, it is judged as other types of loss.

8. The communication optical cable line fault rapid location system according to claim 7, characterized in that: The other types of losses include optical fiber breakage and poor splicing. The optical fiber breakage is manifested in the optical time domain reflection curve as a sudden drop in reflected light power to near zero, and the poor splicing is manifested as an obvious loss peak at the splicing point.

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