An optical cable co-routing detection device and method

Abstract

The present invention relates to the identification technology of optical cable same route, and specifically relates to a method and system for automatically detecting the same route of optical cables by using distributed optical fiber sensing technology. The present invention includes an optical cable detection unit, a data processing unit, and display and communication devices. Among them, the optical cable detection unit includes two detection channels, and the two detection channels are respectively used to obtain the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable; the data processing unit is used to collect the backward Rayleigh scattering signals of the main optical cable and the backup optical cable, analyze the vibration events around the main optical cable and the backup optical cable, and confirm the same route state of the main optical cable and the backup optical cable by performing correlation analysis on the vibration signals of the main and backup optical cables. The present invention does not require maintenance personnel to go out for testing. The optical cable can be connected to the device in the computer room, and the test results can be sent to the user terminal in real time, greatly improving the efficiency and accuracy of the same route test.

Description

Technical Field

[0001] The present invention relates to the identification technology of the same route of optical cables, and specifically relates to a method and system for automatically detecting the same route of optical cables by using the technology of distributed optical fiber sensing. Background Art

[0002] The same route of optical cables is a very major hidden danger causing communication service interruption in transmission networking. The hidden dangers of the same route are mainly divided into several categories such as the same cable same route (same cable same route), same pole (duct) same route, and near pole (duct) same route. Due to the passive characteristics of optical cables, the huge "dumb resources" of optical cables cannot achieve visual state management. Therefore, the routing information in the existing asset management system mainly relies on manual data entry. However, continuous capacity expansion construction and frequent accident repairs have made it increasingly difficult to synchronize the optical cable pipeline resource data in real time, and the deviation between the corresponding relationship of the physical network and the logical network has also become larger and larger. Although the optical network service has perfect logical link primary and backup path protection measures, once the primary and backup paths are in the same physical optical cable, the risk probability of service interruption caused by fiber breakage accidents will also increase greatly. However, there has always been a lack of effective technical means for verifying the same route optical cables, resulting in large-scale interruptions of network communication services many times.

[0003] Making the optical cable "speak up" is the key to realizing "same route detection". Based on the distributed optical fiber sensing technology of Rayleigh backscattering, it can simultaneously access the primary and backup optical cables for high-sensitivity vibration detection, accurately identify changes in the external environment such as vibrations caused by construction or passing vehicles near the optical cable, and perform correlation analysis, so as to automatically identify whether any two service routes are all or partially on the same route. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method and detection device for the same route of optical cables to solve the pain points of the same route detection existing in the prior art. The present invention proposes a distributed optical fiber sensing technology based on Rayleigh backscattering, and determines the same route state of the primary and backup optical cables by detecting and analyzing the active or passive external vibrations around the primary optical cable and the backup optical cable.

[0005] The technical solution of the present invention is: a method for detecting the same route of optical cables, characterized by including the following steps:

[0006] Step 1: The optical cable detection unit continuously receives the Rayleigh backscattering optical signals of the two optical cables, namely the primary optical cable and the backup optical cable;

[0007] Step 2: After the data processing unit collects and receives the Rayleigh backscattering signal data, it extracts the effective vibration event signal interval; in this fixed interval, it extracts the effective vibration event signals of the two optical cables (the primary optical cable and the backup optical cable) in the same time period;

[0008] Step 3: Perform a correlation analysis on the effective vibration events A extracted from the main optical cable and the effective vibration events B extracted from the backup optical cable.

[0009] Step 4: Continuously perform the tests in Step 2 and Step 3. The optical cable section where the correlation analysis result exceeds the same-route determination standard is the same-route section.

[0010] Step 5: According to the test results in Step 4, compare and match with the routing data in the asset management system, verify the physical location of the same-route section, and display the start and end lengths of the main and backup optical cables with the same route on the terminal.

[0011] The present invention also discloses an optical cable same-route detection device, which includes an optical cable detection unit and a data processing unit; characterized in that: the optical cable detection unit contains 2 detection channels, and the 2 detection channels are respectively used to obtain the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable; the data processing unit is used to receive and collect the backward Rayleigh scattering signals of the main optical cable and the backup optical cable, analyze the vibration events around the main optical cable and the backup optical cable, and confirm the same-route status of the main and backup optical cables by performing a correlation analysis on the vibration signals of the main and backup optical cables.

[0012] According to the above-mentioned optical cable same-route detection device, characterized in that: the optical cable detection unit includes a light source, a modulator, an optical amplifier, a photodetector 1 and a photodetector 2. The light source, the modulator and the optical amplifier are sequentially connected and then respectively connected to the main optical cable and the backup optical cable, and the photodetector 1 and the photodetector 2 are respectively connected to the main optical cable and the backup optical cable.

[0013] According to the above-mentioned optical cable same-route detection device, characterized in that: it includes a terminal display and communication device, which can be connected to the data processing unit by wired and wireless methods to display the determination result and notify the user.

[0014] The beneficial effects of the present invention are: the same-route detection method and device proposed by the invention are simple to operate, without the need for maintenance personnel to go out for testing. The optical cable can be connected to the device in the computer room, greatly improving the efficiency and accuracy of the same-route test. The phenomenon of simultaneous failures of the main and backup optical cables caused by external damage is eliminated at the design and implementation stage of the optical cable; for the already laid optical cables, rapid detection and rectification of the main and backup optical cables can be carried out, greatly reducing the economic losses caused by optical cable damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the device of the present invention.

[0016] Figure 2 It is a schematic diagram of the event judgment of the present invention.

[0017] Figure 3 It is a detailed schematic diagram of the device of the present invention. Detailed implementation mode

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0019] As Figures 1 to 3 shown, an optical cable same-route detection device of the present invention includes: an optical cable detection unit, a data processing unit, and a display and communication device; the optical cable detection unit includes 2 detection channels, and two optical cables to be measured can be connected at the same time, and are used to obtain the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable (or called the optical fiber to be measured 1 and the optical fiber to be measured 2); the data processing unit is used to receive and collect the backward Rayleigh scattering signals of the main and backup optical cables, analyze the vibration events around the main and backup optical cables, and the vibration signals include automobiles, construction machinery, knocking, etc. The vibration signals are not limited to being generated by passive sources, but can also be artificially generated knocking signals. By performing a correlation analysis on the vibration signals of the main and backup optical cables, the same-route state of the main and backup optical cables can be confirmed. The present invention may further include a display and communication device, and the display device is connected to the data processing unit for displaying the processing result and notifying the terminal user.

[0020] As Figure 3 shown, the optical cable detection unit of the present invention includes a light source, a modulator, an optical amplifier, a photodetector 1, and a photodetector 2. The light source, the modulator, and the optical amplifier are sequentially connected and then respectively connected to the main optical cable and the backup optical cable. The photodetector 1 and the photodetector 2 are respectively connected to the main optical cable and the backup optical cable. In this way, the same light source is output to the main optical cable and the backup optical cable through the optical amplifier, and the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable are obtained through the photodetector 1 and the photodetector 2. When an external disturbance acts on the sensing optical fiber, it will change the refractive index of the sensing optical fiber, causing intensity and phase modulation of the Rayleigh scattering light. By demodulating the intensity or phase information of the backward Rayleigh scattering light pulse signal in the optical cable, distributed monitoring of the vibration events along the optical cable can be performed.

[0021] The present invention also discloses an optical cable same-route detection method, including the following steps:

[0022] Step 1: Record the signal C1 of the main optical cable and the signal C2 of the backup optical cable in a static environment, and then use the vibration of the passive source in the natural environment or the vibration signal of artificially made knocking. The optical cable detection unit receives the backward Rayleigh scattering optical signals of the two optical cables, the main optical cable and the backup optical cable, in real time. The received signal of the main optical cable is defined as X, and the signal of the backup optical cable is defined as Y;

[0023] Step 2: Taking the extraction of the vibration event signal of the main optical cable as an example, after the data processing unit receives the backward Rayleigh scattering signal data, it compares and analyzes the differences in energy and average frequency between signal X and C1. Among them, for energy, the mean value of the signal intensity within a certain time period can be selected as the identifier, and for the average frequency, the zero-crossing rate of the signal within the same time period is used as the identifier. Select the interval with a large difference, and obtain the time-domain change signal within a certain time period in this interval, which is the effective vibration signal A of the optical cable. Perform the same operation on the backup optical cable to obtain the effective vibration signal B.

[0024] It should be noted that the mean value of intensity and the zero-crossing rate are specific parameters selected in this embodiment. Using other similar energy or frequency differences for signal extraction should be regarded as deformations and combinations that do not deviate from the essence of the present invention, and these deformations and combinations are still within the protection scope of the present invention.

[0025] Step 3: Perform a correlation analysis on the vibration event A of the main optical cable and the vibration event B of the backup optical cable. Specifically, first extract the duration TA and TB of the vibration signal, calculate the ratio, then extract the time-frequency domain structure features of the signal, including features such as waveform and line spectrum, and then calculate the Pearson correlation coefficient of these features. Different weights are assigned to the duration, waveform correlation coefficient, and line spectrum feature correlation coefficient. In this embodiment, they are [0.1, 0.6, 0.3] respectively, and the final similarity value S is calculated. When S is greater than 0.9, it is determined that A and B are the same vibration event, and it can be determined that the main optical cable and the backup optical cable have the same routing interval.

[0026] The operation formula of the Pearson correlation coefficient is as follows:

[0027]

[0028] Where μA and σ are the mean value and standard deviation of A respectively, μB and σB are the mean value and standard deviation of B respectively, and N is the number of event data of A and B.

[0029] Step 4: Continuously perform the tests in Step 2 and Step 3 for 5 hours. The optical cable intervals determined to be strongly correlated through the above correlation analysis method are of the same routing; since the external vibration is used as the excitation source, the longer the duration, the more samples of external vibration events are obtained on the entire optical cable, and the more complete the detection of the optical cable is, and the higher the accuracy of the same routing judgment and the positioning accuracy.

[0030] According to the results of the mutual analysis, Event 1 and Event 3 are not correlated in terms of duration, waveform, and line spectrum features, and the comprehensive similarity value S tends to 0. The correlation coefficients of the duration, waveform, and line spectrum features between Event 2 and Event 3 are all greater than 0.9, and the comprehensive similarity value tends to 1. It is determined that the main optical cable L1-L2 and the backup optical cable L3-L4 are of the same routing interval, and the optical cable length positions L1-L2 and L3-L4 are sent to the terminal for display.

[0031] Step 5: Based on the test results in Step 4, match with the data in the asset management system. If there is no GIS map record of the main and standby optical cables in the asset management system, the physical location of the same-route section can be further determined by manual tapping.

Claims

1. A method for detecting the same route of an optical cable, characterized in that: It includes the following steps: Step 1: The optical cable detection unit receives the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable in real time; Step 2: After the data processing unit collects the received backward Rayleigh scattering signal data, it extracts the effective vibration event signal interval; within this fixed interval, it extracts the effective vibration event signals of the main optical cable and the backup optical cable in the same time period; the method for extracting the vibration event signal is: according to the Rayleigh scattering signal, compare the energy and frequency differences between this signal and the static signal, and select the interval with larger differences as the occurrence interval of the event; fix and select this interval, and extract the effective vibration signals of the two optical cables in the same time period; Step 3: Perform a correlation analysis on the effective vibration event A extracted from the main optical cable and the effective vibration event B extracted from the backup optical cable; the method for the correlation analysis of the vibration event is: including the correlation analysis of the duration, waveform and time-frequency domain structure parameters of the vibration event, calculate the similarity coefficients of different parameters, and take the absolute value; The calculation methods of its similarity coefficients include typical calculation methods such as Pearson correlation coefficient, Spearman correlation coefficient, and Kendall correlation coefficient; Step 4: Continuously perform the tests in Step 2 and Step 3, and determine the optical cable intervals whose correlation analysis results exceed the same-route standard as the same-route intervals; Step 5: According to the test results in Step 4, compare and match with the routing data in the asset management system, verify the physical positions of the same-route intervals, and send the determination results to the user terminal. The results include the start and end lengths of the main optical cable and the backup optical cable in the same-route intervals.

2. An optical cable co-routing detection device, comprising an optical cable detection unit and a data processing unit; characterized in that: The optical cable detection unit includes 2 detection channels, and the 2 detection channels are respectively used to obtain the backward Rayleigh scattering optical signals of the main optical cable and the backup optical cable; the data processing unit is used to receive and collect the backward Rayleigh scattering signals of the main optical cable and the backup optical cable, analyze the vibration events around the main optical cable and the backup optical cable, and confirm the same-route status of the main and backup optical cables by performing a correlation analysis on the vibration signals of the main and backup optical cables. The data processing unit uses the optical cable same-route detection method described in Claim 1 to determine the same-route intervals of the main optical cable and the backup optical cable.

3. The optical cable co-routing detection device according to claim 2, wherein: The optical cable detection unit includes a light source, a modulator, an optical amplifier, and photodetector 1 and photodetector 2. The light source, the modulator, and the optical amplifier are sequentially connected and then respectively connected to the main optical cable and the backup optical cable. Photodetector 1 and photodetector 2 are respectively connected to the main optical cable and the backup optical cable.

4. An optical cable co-routing detection device according to claim 2, characterized in that: It may also include a terminal display and communication device, which can be connected to the data processing unit by wire or wirelessly, display the determination results and notify the user.

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