WO-2026091333-A1 - OTDR-BASED OPTICAL CABLE TEST METHOD AND SYSTEM, OPTICAL TIME DOMAIN REFLECTION DEVICE AND MEDIUM

WO2026091333A1WO 2026091333 A1WO2026091333 A1WO 2026091333A1WO-2026091333-A1

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.

Inventors

OU, Xiuping
CAI, JUN
LUO, Dingyuan

Assignees

高勘(广州)技术有限公司

Dates

Publication Date: 20260507
Application Date: 20250213
Priority Date: 20241031

Claims (20)

An OTDR-based optical cable testing method, characterized in that the OTDR-based optical cable testing method includes: The optical cable is measured by the maximum test pulse width that meets the maximum gain of the optical cable, 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.
According to claim 1, the OTDR-based optical cable testing method is 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.
According to claim 2, the OTDR-based optical cable testing method is characterized in that, the step 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.
The optical cable testing method based on OTDR according to any one of claims 1-3 is characterized in that, the step 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.
The optical cable testing method based on OTDR according to any one of claims 1-3 is characterized in that, the step of obtaining the corresponding normal optical cable segment in the test curve data according to the starting point and ending point 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.
According to claim 5, the OTDR-based optical cable testing method is characterized in that 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.
According to the OTDR-based optical cable testing method of claim 6, 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.
The optical cable testing method based on OTDR according to claim 7 is characterized in that the preset margin is set to 5-8 dB.
The optical cable testing method based on OTDR according to any one of claims 1-3 is characterized in that, after acquiring the corresponding test curve data, it further includes: The test curve data is displayed using an optical time-domain reflectometer.
The optical cable testing method based on OTDR according to any one of claims 1-3 is characterized in that, obtaining the test distance of the optical cable based on the length of the optical cable specifically comprises: The test distance is set to 1.5-2 times the length of the optical cable.
An OTDR-based optical cable testing system, characterized in that the OTDR-based optical cable testing system comprises: 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.
According to the OTDR-based optical cable testing system of claim 11, 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.
According to the OTDR-based optical cable testing system of claim 12, the step 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.
According to any one of claims 11-13, the OTDR-based optical cable testing system is characterized in that, the step 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.
The OTDR-based optical cable testing system according to any one of claims 11-13 is 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 calibration 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.
According to the OTDR-based optical cable testing system of claim 15, 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.
According to the OTDR-based optical cable testing system of claim 16, 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.
The OTDR-based optical cable testing system according to claim 17 is characterized in that the preset margin is set to 5-8 dB.
An optical time-domain reflectometry (OTDR) device includes 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.
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.

Description

OTDR-based optical cable testing methods, systems, optical time domain reflectance devices, and media. Technical Field 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 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. Attached Figure Description Figure 1 is a flowchart of the testing method of the present invention. Figure 2 is a schematic diagram of the test curve data of the present invention. Figure 3 is a system structure diagram of the test system of the present invention. Figure 4 is a structural diagram of the optical time-domain reflectometry device of the present invention. 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 Example 1 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. 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. 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: S1: Measure the optical cable using the maximum test pulse width that meets the maximum gain requirement, and obtain the corresponding test curve data; 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. 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. 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; In this embodi