OTDR-based optical cable test method and system, optical time domain reflection device and medium

Abstract

An OTDR-based optical cable test method: measuring an optical cable by means of the maximum test pulse width satisfying the maximum gain of the optical cable, and acquiring test curve data and a corrected event start point and an event end point of each signal change event thereon; on the basis of the corrected event start points and the event end points, acquiring a normal optical cable segment in the test curve data; fitting the test curve data to obtain the optical cable length of the optical cable; on the basis of the optical cable length, acquiring a test distance of the optical cable; and, on the basis of the normal optical cable segment, acquiring the minimum test pulse width for an optical cable test. Compared with the prior art, directly using the maximum test pulse width that can meet the maximum gain of the optical cable to measure and obtain the test curve data, which can reflect the measurement situation of the optical cable at the maximum gain, can quickly acquire at a time various parameter information that needs to be set for the test, so as to improve the accuracy and efficiency of the optical cable test. Further provided are an OTDR optical cable test system, an optical time domain reflection device, and a storage medium.

Description

OTDR-based optical cable testing methods, systems, optical time domain reflectance devices, and media. Technical Field

[0001] This invention relates to the field of optical cable maintenance, and more specifically, to an optical cable testing method, system, optical time domain reflectance device, and medium based on OTDR. Background Technology

[0002] Distributed fiber optic testing equipment can test the length and line quality of optical cables. However, during testing, increasing the measurement distance requires selecting a larger test pulse width, which reduces event resolution. Therefore, it is difficult to achieve a balance between measurement distance and event resolution. In practical applications, appropriate parameters such as test pulse width and test distance need to be set to obtain maximum testing accuracy while meeting the test length requirements. Technical issues

[0003] The present invention aims to overcome at least one of the defects of the prior art and provide an OTDR-based optical cable testing method, system, optical time domain reflectance device and medium, which can quickly and effectively obtain appropriate test pulse width and test distance to achieve more accurate optical cable testing. Technical solutions

[0004] The technical solution adopted in this invention is as follows:

[0005] In a first aspect, the present invention provides an OTDR-based optical cable testing method, the OTDR-based optical cable testing method comprising:

[0006] The optical cable is measured using the maximum test pulse width that meets the maximum gain requirement, and the corresponding test curve data is obtained. The test curve data is used to reflect the length-signal condition of the optical cable.

[0007] The start and end points of the signal change events are obtained based on the test curve data, and the start points are corrected to obtain the corresponding corrected start points.

[0008] Obtain the corresponding normal optical cable segment in the test curve data based on the start and end points of the correction event;

[0009] The optical cable length of the optical cable is obtained by fitting the test curve data;

[0010] The test distance of the optical cable is obtained based on the length of the optical cable;

[0011] The minimum test pulse width for optical cable testing is obtained based on the normal optical cable segment.

[0012] By directly measuring the maximum test pulse width that meets the maximum gain of the optical cable, the test curve data can reflect the measurement situation of the optical cable at the maximum gain, including various event points on the optical cable, the length of the optical cable, and the overall loss of the optical cable. Based on the various information on the optical cable obtained from the test curve data, various parameter information of the optical cable used for testing can be obtained quickly and effectively.

[0013] Furthermore, the step of obtaining the start and end points of the signal change event based on the test curve data specifically includes:

[0014] In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained;

[0015] The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

[0016] The decrease amplitude refers to the change in signal strength per unit distance. If the decrease amplitude of the signal strength exceeds a preset threshold, it indicates that a power loss event has occurred at that location on the optical cable. By calculating the decrease amplitude of the signal strength, the location of each power loss event on the optical cable can be accurately determined.

[0017] Furthermore, the step of correcting the event starting point to obtain the corresponding corrected event starting point specifically includes:

[0018] From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise;

[0019] The starting point of the obtained curve segment is taken as the starting point of the correction event;

[0020] If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed.

[0021] If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

[0022] By correcting the starting point of the event, the coverage of the event can be adjusted, thereby integrating some events with an inclusion relationship. On the one hand, this facilitates the viewing and analysis of the events; on the other hand, after integrating the events, the area of ​​normal loss in the test curve data can be reduced, which facilitates subsequent calculations.

[0023] Furthermore, the process of fitting the test curve data to obtain the optical cable length specifically includes:

[0024] Fit the test curve data;

[0025] The length of the optical cable corresponding to the final event starting point is obtained from the fitted test curve data and is taken as the optical cable length.

[0026] The final event starting point represents the last event point on the optical cable where loss occurs. This loss is usually caused by the connection between the end of the optical cable and the device. Therefore, by obtaining the final event starting point, the length of the optical cable can be effectively obtained.

[0027] Furthermore, obtaining the corresponding normal optical cable segment from the test curve data based on the start and end points of the correction event specifically includes:

[0028] The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data.

[0029] The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

[0030] Furthermore, obtaining the minimum test pulse width for optical cable testing based on the normal optical cable segment specifically includes:

[0031] The difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data is used as the dynamic range of the optical cable, and the minimum test pulse width for the optical cable test is obtained based on the dynamic range of the optical cable.

[0032] By taking the corrected starting point of the correction event as the abnormal power rise point, and the final starting point of the correction event as the lowest point of signal strength on the optical cable, and the starting point of the initial normal optical cable segment as the highest point of signal strength on the optical cable, the power attenuation of the optical cable can be effectively obtained by calculating the difference in signal strength between the starting point of the initial normal optical cable segment and the starting point of the final correction event. This allows for the effective acquisition of the minimum test pulse width of the optical cable.

[0033] Furthermore, obtaining the minimum test pulse width for optical cable testing based on the dynamic range of the optical cable specifically includes:

[0034] Adding a preset margin to the dynamic range yields the corrected dynamic range.

[0035] A certain margin is added to the dynamic range for correction to ensure that the corrected dynamic range can better realize the measurement of the optical cable and fully display the measurement results.

[0036] Furthermore, the preset margin is set to 5-8 dB.

[0037] Furthermore, the step of generating the corresponding test curve data based on the reflected signal further includes:

[0038] The test curve data is displayed using the optical time-domain reflectometer.

[0039] Furthermore, obtaining the test distance of the optical cable based on the optical cable length specifically involves:

[0040] The test distance is set to 1.5-2 times the length of the optical cable.

[0041] In a second aspect, the present invention also provides an OTDR-based optical cable testing system, the OTDR-based optical cable testing system comprising:

[0042] The test curve acquisition module is used to measure the optical cable by using the maximum test pulse width that meets the maximum gain of the optical cable, and to acquire the corresponding test curve data; the test curve data is used to reflect the length-signal condition of the optical cable.

[0043] The event point acquisition module is used to acquire the event start point and event end point of the signal change event based on the test curve data, and to correct the event start point to obtain the corresponding corrected event start point;

[0044] The optical cable segment acquisition module is used to acquire the corresponding normal optical cable segment in the test curve data based on the starting point and ending point of the correction event.

[0045] The optical cable fitting module is used to fit the test curve data to obtain the optical cable length.

[0046] The test distance acquisition module is used to acquire the test distance of the optical cable based on the length of the optical cable;

[0047] The test pulse width acquisition module is used to acquire the minimum test pulse width for optical cable testing based on the normal optical cable segment.

[0048] Furthermore, the step of obtaining the start and end points of the signal change event based on the test curve data specifically includes:

[0049] In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained;

[0050] The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

[0051] Furthermore, the step of correcting the event starting point to obtain the corresponding corrected event starting point specifically includes:

[0052] From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise;

[0053] The starting point of the obtained curve segment is taken as the starting point of the correction event;

[0054] If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed.

[0055] If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

[0056] Furthermore, the process of fitting the test curve data to obtain the optical cable length specifically includes:

[0057] Fit the test curve data;

[0058] From the fitted test curve data, the length of the optical cable corresponding to the last event starting point is obtained as the optical cable length.

[0059] Furthermore, obtaining the corresponding normal optical cable segment in the test curve data based on the start and end points of the correction event specifically includes:

[0060] The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data.

[0061] The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

[0062] Furthermore, obtaining the minimum test pulse width for optical cable testing based on the normal optical cable segment specifically includes:

[0063] The difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data is used as the dynamic range of the optical cable, and the minimum test pulse width for the optical cable test is obtained based on the dynamic range of the optical cable.

[0064] Furthermore, obtaining the minimum test pulse width for optical cable testing based on the dynamic range of the optical cable specifically includes:

[0065] Adding a preset margin to the dynamic range yields the corrected dynamic range.

[0066] Furthermore, the preset margin is set to 5-8 dB.

[0067] In a third aspect, the present invention also provides an optical time-domain reflectometry device, including a memory and a processor, wherein the memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the OTDR-based optical cable testing method described in the first aspect above.

[0068] In a fourth aspect, the present invention also provides a computer storage medium having a computer-readable program stored thereon, wherein when the computer-readable program is executed, it implements the OTDR-based optical cable testing method described in the first aspect above. Beneficial effects

[0069] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0070] This invention obtains the test curve data by directly measuring the maximum test pulse width that meets the maximum gain of the optical cable. The obtained test curve data can reflect the measurement situation of the optical cable at the maximum gain. In addition, it can obtain optical cable information such as the event start point, event end point, calibration event point, and normal optical cable segment in the test curve data. Based on the various optical cable information on the optical cable obtained from the test curve data, the test distance and minimum test pulse width of the optical cable for testing can be obtained quickly and effectively. Attached Figure Description

[0071] Figure 1 is a flowchart of the testing method of the present invention.

[0072] Figure 2 is a schematic diagram of the test curve data of the present invention.

[0073] Figure 3 is a system structure diagram of the test system of the present invention.

[0074] Figure 4 is a structural diagram of the optical time-domain reflectometry device of the present invention.

[0075] Figure captions: Test curve acquisition module 11, event point acquisition module 12, optical cable segment acquisition module 13, optical cable fitting module 14, test distance acquisition module 15, test pulse width acquisition module 16, memory 21, processor 22, bus 23, communication interface 24. Embodiments of the present invention

[0076] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Example 1

[0077] With the continuous development of fiber optic communication technology, the laying of optical cables has gradually increased. After the optical cables are laid but before they are put into actual use, their performance needs to be tested to detect and eliminate faults. In existing technology, optical time domain reflectometers (OTDRs) are typically used to measure the performance of optical cables. High-power lasers or light pulses are usually injected into one end of the cable, and the reflected signal is received on the same side. However, during measurement, appropriate measurement parameters need to be manually set. To increase the measurement distance, a larger test pulse width is required. However, as the test pulse width increases, the event resolution decreases. Therefore, it is difficult to balance the measurement distance and the event resolution. In actual testing, appropriate test parameters such as the test pulse width and test distance need to be set to improve test accuracy while meeting the test length requirements.

[0078] To effectively address the problems existing in the prior art, as shown in Figure 1, this embodiment provides an OTDR-based optical cable testing method, the method comprising:

[0079] S1: Measure the optical cable by using the maximum test pulse width that meets the maximum gain of the optical cable, and obtain the corresponding test curve data;

[0080] In this embodiment, specifically, the optical cable is measured using an optical time domain reflectometer. The optical time domain reflectometer is connected to the optical cable to be tested. Then, light with the maximum test pulse width that meets the maximum gain of the optical cable is incident from one end of the optical cable, and the corresponding reflected signal is received at the other end, thereby forming the test curve data. The test curve data is then displayed through the display device of the optical time domain reflectometer.

[0081] As shown in Figure 2, the test curve data represents the relationship between the measured optical cable length and signal strength. The horizontal axis represents the measured length of the optical cable, and the vertical axis represents the signal strength at the corresponding length position of the optical cable. Therefore, the test curve data can reflect the signal situation at various points on the optical cable. In this embodiment, light with the maximum gain and maximum test pulse width is incident on the optical cable. Under the action of the light with the maximum test pulse width, the corresponding test curve data is obtained, which effectively reflects the effective test distance of the optical cable and the power attenuation of the optical cable, thereby enabling convenient and quick setting of the test parameters of the optical cable.

[0082] S2: Obtain the start and end points of the signal change event based on the test curve data, and correct the start point of the event to obtain the corresponding corrected start point of the event;

[0083] In this embodiment, as shown in Figure 2, the test curve data generally shows a downward trend. This is because light will be lost during transmission in the optical cable, causing the signal strength of the light to gradually decrease as the length of the optical cable increases.

[0084] Furthermore, as can be seen from Figure 2, the signal strength at several locations in the test curve data suddenly dropped sharply before stabilizing. This indicates that signal change events occurred at these locations on the optical cable. These signal change events may include reflection events / signal attenuation events. These reflection events / signal attenuation events may be caused by external environmental factors, such as optical cable bending or damage, or they may be caused by some conventional factors, such as attenuation at the interface due to optical cable splicing.

[0085] Therefore, by obtaining the start and end points of the signal change events, it is beneficial to identify the signal change events, determine which are caused by conventional factors and which are caused by external environmental factors, and thus realize the maintenance of optical cables.

[0086] Specifically, in this embodiment, obtaining the event start point and event end point may include:

[0087] In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained; the decrease refers to the change in signal strength per unit distance. When the decrease in signal strength exceeds the preset threshold, it indicates that the signal strength has experienced a precipitous drop, and it can be determined that an event causing signal attenuation and loss has occurred at this point.

[0088] The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

[0089] The event starting point obtained through the above method can only include a portion of signal change events. As shown in Figure 3, some signals may suddenly rise before attenuation, and then experience a sharp drop after reaching a certain height. Therefore, the event starting point and corresponding event ending point calculated solely through the above method cannot completely cover the entire range of signal change events. Furthermore, in actual measurement, even after the signal strength has dropped to 0 outside the length of the optical cable, some rapid increases and decreases in signal strength may still occur. These signal strength changes are caused by interference in the optical cable and need to be eliminated. Additionally, the signal change events obtained from the test curve data are too dense, making observation of these events inconvenient. Therefore, the event starting point needs to be calibrated. Specifically, the calibration includes:

[0090] From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise;

[0091] The starting point of the obtained curve segment is taken as the starting point of the correction event;

[0092] If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed.

[0093] This step is mainly to eliminate interference signal changes outside the length range of the optical cable. Because the signal strength on the optical cable is constantly attenuating, even if the signal strength increases within a certain range due to reflection, the signal strength at the corresponding endpoints of the corrected signal change event will always be less than the signal strength at the endpoint of the corrected event. Therefore, interference can be identified and removed in this way.

[0094] If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

[0095] This step primarily involves merging all signal change events that are too close together. In real-world scenarios, the impact of events affecting signal strength on the optical cable is localized, typically manifesting as signal strength variations within a specific length of the cable. Therefore, if multiple signal change events are too close together, it indicates that they are essentially the same event. Merging these closely spaced events consolidates identical signal change events and facilitates the observation of the test curve data.

[0096] The corrected event starting point, compared to the original event starting point, has a larger coverage area and can include more signal change events. At the same time, by adjusting the starting point of the signal change events, some signal change events with similar properties can be integrated, which facilitates the subsequent calculation of normal optical cable segments and the fitting of the test curve data.

[0097] S3: Obtain the normal optical cable segment corresponding to the test curve data based on the starting point and ending point of the correction event;

[0098] Specifically, in this embodiment, obtaining the normal optical cable segment may include:

[0099] The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data.

[0100] The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

[0101] As described above and referring to Figures 2-4, the normal optical cable segment represents the area in the test curve data where the signal strength is normally lost. Therefore, the curve segment where normal loss occurs between each of the signal change events is taken as the normal optical cable segment. Multiple normal optical cable segments can be obtained in the test curve data. The normal optical cable segment and the signal change event represent the actual length of the optical cable.

[0102] The starting point of the first normal optical cable segment is the starting point of the optical cable, that is, the port connected to the optical time domain reflectometer. Since it is connected to the optical time domain reflectometer, a reflection event is generated at the starting point. Correspondingly, the ending point of the last normal optical cable segment is the end of the optical cable.

[0103] S4: Fit the test curve data to obtain the optical cable length of the optical cable;

[0104] In this embodiment, specifically, the optical cable length can be obtained by taking the length of the optical cable corresponding to the last event starting point in the fitted test curve data as the optical cable length. The fitting of the test curve data can be specifically achieved by fitting the average signal strength of the test curve data within a certain distance range to obtain a smooth fitted test curve.

[0105] The fitted test curve data includes all the normal optical cable segments and signal change events, so the coverage of the fitted test curve data includes the optical cable length. At the end of the optical cable, since the optical cable is connected to the optical cable equipment, signal reflection will occur at the end of the optical cable, i.e., a reflection event, and the signal strength will drop to 0. Therefore, the position of the starting point of the last event in the fitted test curve data is the optical cable length, which can quickly obtain the optical cable length.

[0106] S5: Obtain the test distance of the optical cable based on the length of the optical cable;

[0107] After obtaining the optical cable length, it is necessary to further obtain the test distance for optical cable testing. The test distance represents the display range of the test curve data on the display device of the optical time domain reflectometer. In order to better display, in this embodiment, the test distance can be set to 1.5-2 times the optical cable length. The test curve data set in this way can better and more completely display the relationship between the optical cable length and the signal strength, and facilitate optical cable testing and repositioning of the test distance when the optical cable needs to be added later.

[0108] S6: Obtain the minimum test pulse width for optical cable testing based on the normal optical cable segment.

[0109] As described above, the starting point of the first normal optical cable segment corresponds to the front end of the optical cable, and the ending point of the last normal optical cable segment corresponds to the end of the optical cable. Therefore, the dynamic range of the optical cable can be determined based on the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment. The dynamic range represents the range of normal losses in the optical cable. Therefore, in this embodiment, the difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data can be used as the test dynamic range of the optical cable.

[0110] Understandably, the obtained dynamic range is "just right" sufficient for testing the optical cable. However, setting the test parameters in this way may result in some errors. This is because, during actual testing, if the loss exceeds the dynamic range, the excess portion cannot be detected. Therefore, after obtaining the dynamic range, it needs to be corrected. Specifically, a preset margin can be added to the dynamic range for correction. Only the corrected dynamic range can then be used as the minimum test pulse width for optical cable testing. Preferably, the preset margin can be set to 5-8 dB.

[0111] After obtaining the corrected dynamic range, the minimum test pulse width that meets the requirements can be selected based on the dynamic range.

[0112] In this embodiment, the optical cable is measured by using the maximum test pulse width that meets the maximum gain of the optical cable. The test curve data obtained by using the maximum test pulse width can effectively reflect various information on the optical cable and can obtain information on various parameters that need to be set for testing at one time, thereby enabling the rapid and effective acquisition of optical cable test parameter information.

[0113] Example 2

[0114] As shown in Figure 3, this embodiment provides an OTDR-based optical cable testing system, the system comprising:

[0115] The test curve acquisition module 11 is used to measure the optical cable by using the maximum test pulse width that meets the maximum gain of the optical cable, and acquire the corresponding test curve data; the test curve data reflects the length-signal condition of the optical cable.

[0116] In this embodiment, specifically, the optical cable is measured using an optical time domain reflectometer. The optical time domain reflectometer is connected to the optical cable to be tested. Then, light with the maximum test pulse width that meets the maximum gain of the optical cable is incident from one end of the optical cable, and the corresponding reflected signal is received at the other end, thereby forming the test curve data. The test curve data is then displayed through the display device of the optical time domain reflectometer.

[0117] As shown in Figure 2, the test curve data represents the relationship between the measured optical cable length and signal strength. The horizontal axis represents the measured length of the optical cable, and the vertical axis represents the signal strength at the corresponding length position of the optical cable. Therefore, the test curve data can reflect the signal situation at various points on the optical cable. In this embodiment, light with the maximum gain and maximum test pulse width is incident on the optical cable. Under the action of the light with the maximum test pulse width, the corresponding test curve data is obtained, which effectively reflects the effective test distance of the optical cable and the power attenuation of the optical cable, thereby enabling convenient and quick setting of the test parameters of the optical cable.

[0118] The event point acquisition module 12 is used to acquire the event start point and event end point of the signal change event based on the test curve data, and to correct the event start point to obtain the corresponding corrected event start point.

[0119] In this embodiment, as shown in Figure 2, the test curve data generally shows a downward trend. This is because light will be lost during transmission in the optical cable, causing the signal strength of the light to gradually decrease as the length of the optical cable increases.

[0120] Furthermore, as can be seen from Figure 2, the signal strength at several locations in the test curve data suddenly dropped sharply before stabilizing. This indicates that signal change events occurred at these locations on the optical cable. These signal change events may include reflection events / signal attenuation events. These reflection events / signal attenuation events may be caused by external environmental factors, such as optical cable bending or damage, or they may be caused by some conventional factors, such as attenuation at the interface due to optical cable splicing.

[0121] Therefore, by obtaining the start and end points of the signal change events, it is beneficial to identify the signal change events, determine which are caused by conventional factors and which are caused by external environmental factors, and thus realize the maintenance of optical cables.

[0122] Specifically, in this embodiment, obtaining the event start point and event end point may include:

[0123] In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained; the decrease refers to the change in signal strength per unit distance. When the decrease in signal strength exceeds the preset threshold, it indicates that the signal strength has experienced a precipitous drop, and it can be determined that an event causing signal attenuation and loss has occurred at this point.

[0124] The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

[0125] The event starting point obtained through the above method can only include a portion of signal change events. As shown in Figure 3, some signals may suddenly rise before attenuation, and then experience a sharp drop after reaching a certain height. Therefore, the event starting point and corresponding event ending point calculated solely through the above method cannot completely cover the entire range of signal change events. Furthermore, in actual measurement, even after the signal strength has dropped to 0 outside the length of the optical cable, some rapid increases and decreases in signal strength may still occur. These signal strength changes are caused by interference in the optical cable and need to be eliminated. Additionally, the signal change events obtained from the test curve data are too dense, making observation of these events inconvenient. Therefore, the event starting point needs to be calibrated. Specifically, the calibration includes:

[0126] From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise;

[0127] The starting point of the obtained curve segment is taken as the starting point of the correction event;

[0128] If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed.

[0129] This step is mainly to eliminate interference signal changes outside the length range of the optical cable. Because the signal strength on the optical cable is constantly attenuating, even if the signal strength increases within a certain range due to reflection, the signal strength at the corresponding endpoints of the corrected signal change event will always be less than the signal strength at the endpoint of the corrected event. Therefore, interference can be identified and removed in this way.

[0130] If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

[0131] This step primarily involves merging all signal change events that are too close together. In real-world scenarios, the impact of events affecting signal strength on the optical cable is localized, typically manifesting as signal strength variations within a specific length of the cable. Therefore, if multiple signal change events are too close together, it indicates that they are essentially the same event. Merging these closely spaced events consolidates identical signal change events and facilitates the observation of the test curve data.

[0132] The corrected event starting point, compared to the original event starting point, has a larger coverage area and can include more signal change events. At the same time, by adjusting the starting point of the signal change events, some signal change events with similar properties can be integrated, which facilitates the subsequent calculation of normal optical cable segments and the fitting of the test curve data.

[0133] Optical cable segment acquisition module 13 is used to acquire the corresponding normal optical cable segment in the test curve data according to the starting point and ending point of the correction event;

[0134] Specifically, in this embodiment, obtaining the normal optical cable segment may include:

[0135] The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data.

[0136] The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

[0137] As described above and referring to Figures 2-4, the normal optical cable segment represents the area in the test curve data where the signal strength is normally lost. Therefore, the curve segment where normal loss occurs between each of the signal change events is taken as the normal optical cable segment. Multiple normal optical cable segments can be obtained in the test curve data. The normal optical cable segment and the signal change event represent the actual length of the optical cable.

[0138] The starting point of the first normal optical cable segment is the starting point of the optical cable, that is, the port connected to the optical time domain reflectometer. Since it is connected to the optical time domain reflectometer, a reflection event is generated at the starting point. Correspondingly, the ending point of the last normal optical cable segment is the end of the optical cable.

[0139] The optical cable fitting module 14 is used to fit the test curve data to obtain the optical cable length.

[0140] In this embodiment, specifically, the optical cable length can be obtained by taking the length of the optical cable corresponding to the last event starting point in the fitted test curve data as the optical cable length. The fitting of the test curve data can be specifically achieved by fitting the average signal strength of the test curve data within a certain distance range to obtain a smooth fitted test curve.

[0141] The fitted test curve data includes all the normal optical cable segments and signal change events, so the coverage of the fitted test curve data includes the optical cable length. At the end of the optical cable, since the optical cable is connected to the optical cable equipment, signal reflection will occur at the end of the optical cable, i.e., a reflection event, and the signal strength will drop to 0. Therefore, the position of the starting point of the last event in the fitted test curve data is the optical cable length, which can quickly obtain the optical cable length.

[0142] The test distance acquisition module 15 is used to acquire the test distance of the optical cable based on the length of the optical cable;

[0143] After obtaining the optical cable length, it is necessary to further obtain the test distance for optical cable testing. The test distance represents the display range of the test curve data on the display device of the optical time domain reflectometer. In order to better display, in this embodiment, the test distance can be set to 1.5-2 times the optical cable length. The test curve data set in this way can better and more completely display the relationship between the optical cable length and the signal strength, and facilitate optical cable testing and repositioning of the test distance when the optical cable needs to be added later.

[0144] The test pulse width acquisition module 16 is used to acquire the minimum test pulse width for optical cable testing based on the normal optical cable segment.

[0145] As described above, the starting point of the first normal optical cable segment corresponds to the front end of the optical cable, and the ending point of the last normal optical cable segment corresponds to the end of the optical cable. Therefore, the dynamic range of the optical cable can be determined based on the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment. The dynamic range represents the range of normal losses in the optical cable. Therefore, in this embodiment, the difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data can be used as the test dynamic range of the optical cable.

[0146] Understandably, the obtained dynamic range is "just right" sufficient for testing the optical cable. However, setting the test parameters in this way may result in some errors. This is because, during actual testing, if the loss exceeds the dynamic range, the excess portion cannot be detected. Therefore, after obtaining the dynamic range, it needs to be corrected. Specifically, a preset margin can be added to the dynamic range for correction. Only the corrected dynamic range can then be used as the minimum test pulse width for optical cable testing. Preferably, the preset margin can be set to 5-8 dB.

[0147] After obtaining the corrected dynamic range, the minimum test pulse width that meets the requirements can be selected based on the dynamic range.

[0148] Example 3

[0149] As shown in Figure 4, this embodiment provides an optical time-domain reflectometry device, which includes a memory 21 and a processor 22. The memory 21 stores computer-readable instructions, and the processor 22 executes the computer-readable instructions to implement the distributed testing method described in Embodiment 1.

[0150] Preferably, the optical time domain reflectance device further includes a bus 23 and a communication interface 24, and the processor 22, the communication interface 24 and the memory 21 are connected through the bus 23.

[0151] The memory 21 may include high-speed random access memory, and may also include unstable memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 24 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc. The bus 23 may be an ISA bus, PCI bus, or EISA bus, etc. The bus 23 can be divided into address bus, data bus, control bus, etc. (not fully shown in the figure).

[0152] The processor 22 can be an integrated circuit chip with signal processing capabilities. In specific implementations, the steps in the embodiments of the above methods can be completed by the integrated logic circuits in the hardware of the processor 22 or by instructions in software form. The processor 22 can be a general-purpose processor, including a central processing unit, a network processor, etc.; it can also be a digital signal processor, an application-specific integrated circuit, a field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this invention.

[0153] This invention also provides a computer-readable storage medium storing computer-executable instructions. When these computer-executable instructions are invoked and executed by the processor 22, they cause the processor 22 to implement the distributed testing method described above. For specific implementation details, please refer to the embodiments described above, which will not be repeated here.

[0154] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0155] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. An optical cable testing method based on OTDR, characterized in that, The OTDR-based optical cable testing method includes: The optical cable is measured using the maximum test pulse width that meets the maximum gain requirement, and the corresponding test curve data is obtained. The test curve data is used to reflect the length-signal condition of the optical cable. The start and end points of the signal change events are obtained based on the test curve data, and the start points are corrected to obtain the corresponding corrected start points. Obtain the corresponding normal optical cable segment in the test curve data based on the start and end points of the correction event; The optical cable length of the optical cable is obtained by fitting the test curve data; The test distance of the optical cable is obtained based on the length of the optical cable; The minimum test pulse width for optical cable testing is obtained based on the normal optical cable segment.

2. The OTDR-based optical cable testing method according to claim 1, characterized in that, The step of obtaining the start and end points of the signal change event based on the test curve data specifically includes: In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained; The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

3. The OTDR-based optical cable testing method according to claim 2, characterized in that, The process of correcting the event starting point to obtain the corresponding corrected event starting point specifically includes: From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise; The starting point of the obtained curve segment is taken as the starting point of the correction event; If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed. If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

4. The OTDR-based optical cable testing method according to any one of claims 1-3, characterized in that, The process of fitting the test curve data to obtain the optical cable length specifically includes: Fit the test curve data; From the fitted test curve data, the length of the optical cable corresponding to the last event starting point is obtained as the optical cable length.

5. The OTDR-based optical cable testing method according to any one of claims 1-3, characterized in that, The step of obtaining the corresponding normal optical cable segment in the test curve data based on the start and end points of the correction event specifically includes: The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data. The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

6. The OTDR-based optical cable testing method according to claim 5, characterized in that, The step of obtaining the minimum test pulse width for optical cable testing based on the normal optical cable segment specifically includes: The difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data is used as the dynamic range of the optical cable, and the minimum test pulse width for the optical cable test is obtained based on the dynamic range of the optical cable.

7. The OTDR-based optical cable testing method according to claim 6, characterized in that, The step of obtaining the minimum test pulse width for optical cable testing based on the dynamic range of the optical cable specifically includes: Adding a preset margin to the dynamic range yields the corrected dynamic range.

8. The OTDR-based optical cable testing method according to claim 7, characterized in that, The preset margin is set to 5-8 dB.

9. The OTDR-based optical cable testing method according to any one of claims 1-3, characterized in that, After obtaining the corresponding test curve data, the process also includes: The test curve data is displayed using an optical time-domain reflectometer.

10. The OTDR-based optical cable testing method according to any one of claims 1-3, characterized in that, The step of obtaining the test distance of the optical cable based on the length of the optical cable specifically involves: The test distance is set to 1.5-2 times the length of the optical cable.

11. An OTDR-based optical cable testing system, characterized in that, The OTDR-based optical cable testing system includes: The test curve acquisition module is used to measure the optical cable by using the maximum test pulse width that meets the maximum gain of the optical cable, and to acquire the corresponding test curve data; the test curve data is used to reflect the length-signal condition of the optical cable. The event point acquisition module is used to acquire the event start point and event end point of the signal change event based on the test curve data, and to correct the event start point to obtain the corresponding corrected event start point; The optical cable segment acquisition module is used to acquire the corresponding normal optical cable segment in the test curve data based on the starting point and ending point of the correction event. The optical cable fitting module is used to fit the test curve data to obtain the optical cable length. The test distance acquisition module is used to acquire the test distance of the optical cable based on the length of the optical cable; The test pulse width acquisition module is used to acquire the minimum test pulse width for optical cable testing based on the normal optical cable segment.

12. The OTDR-based optical cable testing system according to claim 11, characterized in that, The step of obtaining the start and end points of the signal change event based on the test curve data specifically includes: In the test curve data, the curve segment where the signal strength decreases by more than a preset threshold is obtained; The starting point of the curve segment is taken as the starting point of the signal change event, and the ending point of the curve segment is taken as the ending point of the signal change event.

13. The OTDR-based optical cable testing system according to claim 12, characterized in that, The process of correcting the event starting point to obtain the corresponding corrected event starting point specifically includes: From the test curve data, obtain the curve segment that ends at the starting point of the event and whose signal strength continues to rise; The starting point of the obtained curve segment is taken as the starting point of the correction event; If the signal strength at the starting point of the correction event is the same as the signal strength at the ending point of the corresponding signal change event, then the signal change event is removed. If the distance between the endpoint of one signal change event and the starting point of the correction event of the next signal change event does not exceed a preset distance, then the two signal change events are merged into one signal change event. The starting point of the correction event of the previous signal change event before merging is used as the starting point of the correction event of the merged signal change event, and the endpoint of the next signal change event after merging is used as the endpoint of the merged signal change event.

14. The OTDR-based optical cable testing system according to any one of claims 11-13, characterized in that, The process of fitting the test curve data to obtain the optical cable length specifically includes: Fit the test curve data; From the fitted test curve data, the length of the optical cable corresponding to the last event starting point is obtained as the optical cable length.

15. The OTDR-based optical cable testing system according to any one of claims 11-13, characterized in that, The step of obtaining the corresponding normal optical cable segment in the test curve data based on the start and end points of the correction event specifically includes: The curve segment between two consecutive signal change events in the test curve data is taken as the normal optical cable segment, and several normal optical cable segments are obtained from the test curve data. The normal optical cable segment takes the end point of the previous signal change event in two consecutive signal change events as the starting point and the start point of the correction event in the next signal change event as the ending point.

16. The OTDR-based optical cable testing system according to claim 15, characterized in that, The step of obtaining the minimum test pulse width for optical cable testing based on the normal optical cable segment specifically includes: The difference in signal strength between the starting point of the first normal optical cable segment and the ending point of the last normal optical cable segment in the fitted test curve data is used as the dynamic range of the optical cable, and the minimum test pulse width for the optical cable test is obtained based on the dynamic range of the optical cable.

17. The OTDR-based optical cable testing system according to claim 16, characterized in that, The step of obtaining the minimum test pulse width for optical cable testing based on the dynamic range of the optical cable specifically includes: Adding a preset margin to the dynamic range yields the corrected dynamic range.

18. The OTDR-based optical cable testing system according to claim 17, characterized in that, The preset margin is set to 5-8 dB.

19. An optical time-domain reflectometry device, comprising a memory and a processor, characterized in that, The memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the OTDR-based optical cable testing method according to any one of claims 1-10.

20. A computer storage medium, characterized in that, It stores a computer-readable program thereon, which, when executed, implements the OTDR-based optical cable testing method according to any one of claims 1-10.

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