Submarine cable fault detection method and system

Abstract

The invention relates to the technical field of submarine cable communication, in particular to a submarine cable fault detection method and system. The method is applied to an end station and comprises the steps of determining whether fault detection is performed on a submarine cable to be detected based on detection information, sending a pulse signal to the submarine cable to be detected and receiving a returned scattered light signal under the condition that fault detection is performed on the submarine cable to be detected, and generating a detection curve according to the pulse signal and the scattered light signal; the fault position and the fault type are generated according to the detection curve, the detection information is used for detecting the transmission state of the submarine cable to be detected in real time, the detection information is generated based on a signal received by the end station, and the detection information comprises at least one of a heartbeat signal, optical power and a signal-to-noise ratio. According to the invention, the detection information can be generated based on the signal received by the end station, so that the to-be-detected submarine cable is subjected to front-end real-time detection, the fault position and the fault type of the submarine cable are positioned when the detection result is abnormal, and the efficiency and the accuracy of submarine cable fault detection are improved.

Description

Technical Field

[0001] The present application relates to the field of submarine cable communication technology, and in particular to a submarine cable fault detection method and system. Background Art

[0002] Submarine cables are optical cables laid on the seabed, used to transmit data and signals between various terminals, and carry more than 95% of transoceanic services. However, special situations such as earthquakes, anchors or fishing nets can easily damage submarine cables, leading to severe impacts such as interruption of transoceanic communications and data loss. Therefore, it is necessary to detect faults on submarine cables and locate the faults, so as to achieve automatic disaster recovery of the submarine cable system and ensure normal communication between various terminals.

[0003] The end station uses a coherent optical time domain reflectometer to transmit an optical pulse signal of a specific wavelength to the optical fiber in the submarine cable. During the propagation of the optical signal, due to the Rayleigh scattering principle, the optical signal will be scattered in the submarine cable and generate scattered light. Since the scattered light will have an abnormal optical power at the optical fiber fault point, the end station can determine the location of the fault point in the optical fiber by measuring and analyzing the scattered light. However, since the above process requires multiple transmissions of optical pulse signals and the location of the fault point is detected based on the average value of multiple analysis results, the entire process takes a long time and cannot detect the transmission status of the submarine cable in real time. Therefore, the above method cannot detect submarine cable faults in a timely manner, and thus cannot guarantee the reliability and safety of the operation of the submarine cable system. Summary of the invention

[0004] In order to improve the efficiency and accuracy of submarine cable fault detection, the present application provides a submarine cable fault detection method and system, which can perform pre-detection of the submarine cable in real time and locate the fault position and fault type of the submarine cable when the detection result is abnormal.

[0005] In order to achieve the above-mentioned purpose, in a first aspect, the present application provides a submarine cable fault detection method, comprising: determining whether to perform fault detection on a submarine cable to be detected based on detection information, the detection information being used to detect the transmission status of the submarine cable to be detected in real time, the detection information being generated based on a signal received by an end station, the detection information comprising at least one of a heartbeat signal, optical power and a signal-to-noise ratio; in the case of performing fault detection on the submarine cable to be detected, sending a pulse signal to the submarine cable to be detected, and receiving a returned scattered light signal, and generating a detection curve based on the pulse signal and the scattered light signal; and generating a fault location and a fault type based on the detection curve.

[0006] The submarine cable fault detection method provided by the present application is applied to the terminal station, which can generate detection information based on the received signal, and detect the transmission status of the submarine cable to be detected in real time according to at least one detection information of the heartbeat signal, optical power and signal-to-noise ratio, and perform fault detection on the submarine cable to be detected when the detection result is abnormal, send a pulse signal to the submarine cable to be detected, and receive the returned scattered light signal to locate the fault position and fault type of the submarine cable to be detected. The submarine cable fault detection method provided by the present application can use the terminal station to perform real-time detection of the submarine cable, and improve the efficiency and accuracy of submarine cable fault detection.

[0007] In an optional implementation, determining whether to perform fault detection on the submarine cable to be detected based on the detection information includes: obtaining the detection information, and generating a detection result based on the detection information, the detection result is used to characterize whether the detection information meets the preset conditions; sending the detection result to the network management unit, and obtaining the fault detection identifier returned by the network management unit, the fault detection identifier includes a detection state and a non-detection state, the network management unit is used to generate a fault detection identifier of the submarine cable to be detected based on the detection result and the preset submarine cable topology structure; determining whether to perform fault detection on the submarine cable to be detected based on the fault detection identifier. In this way, the network management unit can generate a fault detection identifier of the submarine cable to be detected based on the detection result of the submarine cable to be detected, combined with the preset submarine cable topology structure, to improve the accuracy of submarine cable fault detection.

[0008] In an optional embodiment, the detection information is obtained, and the detection result is generated based on the detection information, including: obtaining a second signal, the second signal is a signal of the first signal arriving at the terminal after being transmitted based on the submarine cable to be detected, the first signal is a signal sent by the opposite terminal, the first signal includes a first heartbeat signal, the first heartbeat signal is a signal generated by amplitude modulating the total optical power of the first signal, the modulation frequency of the first heartbeat signal is greater than a preset frequency threshold, and the modulation depth of the first heartbeat signal is less than a preset threshold; performing analysis on the second signal to detect whether the second signal includes a second heartbeat signal, the second heartbeat signal is a signal of the first heartbeat signal arriving at the terminal after being transmitted based on the submarine cable to be detected; if the second signal includes the second heartbeat signal, a first detection result is generated, and the first detection result is used to characterize that the second heartbeat signal is in a normal transmission state; if the second signal does not include the second heartbeat signal, a second detection result is generated, and the second detection result is used to characterize that the second heartbeat signal is in an abnormal transmission state. In this way, the terminal determines whether the second heartbeat signal is transmitted normally by detecting whether the second heartbeat signal is included in the received second signal, and then generates a detection result to achieve real-time detection of the submarine cable to be detected.

[0009] In an optional implementation, the terminal station includes an open submarine cable access device, the open submarine cable access device includes a feedback component, and the open submarine cable access device calls the feedback component to enable the feedback component to detect whether the second signal includes the second heartbeat signal. In this way, the terminal station uses the feedback component to detect whether the second signal includes the second heartbeat signal, thereby improving detection efficiency and accuracy.

[0010] In an optional implementation, obtaining detection information and generating a detection result based on the detection information includes: obtaining the optical power of the second signal; generating a third detection result when the optical power is less than a preset optical power threshold, the third detection result is used to indicate that the second signal does not meet the preset optical power condition; generating a fourth detection result when the optical power is greater than or equal to the preset optical power threshold, the fourth detection result is used to indicate that the second signal meets the preset optical power condition. In this way, the terminal determines whether the submarine cable to be detected transmits the second signal normally by detecting whether the optical power of the second signal exceeds the preset optical power threshold, and generates a detection result based on this, thereby realizing real-time detection of the submarine cable to be detected.

[0011] In an optional implementation, the detection information is obtained, and a detection result is generated based on the detection information, including: obtaining a signal-to-noise ratio of the second signal, the signal-to-noise ratio is used to characterize the ratio of optical power to noise power; when the signal-to-noise ratio is greater than or equal to a preset signal-to-noise ratio threshold, a fifth detection result is generated, the fifth detection result is used to characterize that the second signal meets the preset signal-to-noise ratio condition; when the signal-to-noise ratio is less than a preset signal-to-noise ratio threshold, a sixth detection result is generated, the sixth detection result is used to characterize that the second signal does not meet the preset signal-to-noise ratio condition. In this way, the terminal station determines whether the submarine cable to be detected is transmitting the second signal normally by detecting whether the signal-to-noise ratio of the second signal exceeds the preset signal-to-noise ratio threshold, and generates a detection result based on this, thereby realizing real-time detection of the submarine cable to be detected.

[0012] In an optional implementation, the open submarine cable access device further includes a coherent optical time domain reflectometer, and the open submarine cable access device calls the coherent optical time domain reflectometer to enable the coherent optical time domain reflectometer to send a pulse signal to the submarine cable to be detected based on a preset time period and receive a returned scattered light signal. In this way, the terminal station performs fault detection on the submarine cable to be detected by calling the coherent optical time domain reflectometer, thereby improving the accuracy of submarine cable fault detection.

[0013] In an optional embodiment, generating a detection curve based on the pulse signal and the scattered light signal includes: performing coherent processing on the pulse signal and the scattered light signal to generate a coherent signal, wherein the coherent signal includes time information and optical power information; and generating the detection curve based on the correspondence between the time information and the optical power information. In this way, the terminal generates the detection curve based on the optical power information of the coherent signal transmitted in the submarine cable to be detected, thereby improving the accuracy of submarine cable fault detection.

[0014] In an optional implementation, the fault type includes a cable break fault and a non-cable break fault, and the fault location and fault type are generated according to the detection curve, including: marking the fault point based on the detection curve, and the optical power information corresponding to the fault point is lower than the preset standard threshold; obtaining the fault time information, and calculating the fault location according to the fault time information, and the fault time information is the time information corresponding to the fault point; obtaining the reference time information, and obtaining the reference fault point based on the reference time information, and the difference between the reference time information and the fault time information is the preset time difference, the reference time information is after the fault time information, and the reference fault point is the point corresponding to the reference time information in the detection curve; calculating the difference between the optical power corresponding to the fault point and the optical power corresponding to the reference fault point to obtain the fault optical power difference; when the fault optical power difference is greater than the preset optical power difference, marking the fault type as a cable break fault; when the fault optical power difference is less than or equal to the preset optical power difference, marking the fault type as a non-cable break fault. In this way, the terminal station can analyze the fault location and fault cause of the submarine cable to be detected through the corresponding relationship between the time information and the optical power information in the detection curve.

[0015] In an optional implementation, the number of opposite terminal stations is one or more, and at least one submarine cable to be detected is included between the terminal station and the opposite terminal station. In this way, the terminal station can transmit signals with one or more opposite terminal stations, and there are multiple connection modes between the terminal station and the opposite terminal station.

[0016] In an optional implementation, an underwater device is included between the terminal and the opposite terminal, and the underwater device includes at least one of an optical repeater, a splitter, and a reconfigurable optical add / drop multiplexing device, and the terminal and the underwater device are connected based on the submarine cable to be detected. In this way, the signal transmitted between the terminal and the opposite terminal can be amplified or branched by the underwater device, and the terminal and the underwater device can realize segmented detection of the submarine cable based on the connection of the submarine cable to be detected.

[0017] In a second aspect, the present application provides a submarine cable fault detection system, comprising: an end station, an opposite end station, a submarine cable to be detected, and a network management unit. The end station is connected to the opposite end station based on the submarine cable to be detected, and the network management unit communicates with the end station to provide a fault detection identifier to the end station, and the fault detection identifier is used to indicate whether to perform fault detection on the submarine cable to be detected; the end station is configured to perform any submarine cable fault detection method of the first aspect.

[0018] It can be understood that the submarine cable fault detection system provided in the second aspect is applied to the submarine cable fault detection method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the submarine cable fault detection method provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of a process flow of a submarine cable fault detection method provided in this embodiment; Figure 2 A schematic diagram of a terminal device provided in this embodiment; Figure 3 A schematic diagram of a terminal transmission signal provided in this embodiment; Figure 4 A schematic diagram of a modulated heartbeat signal provided in this embodiment; Figure 5 A schematic diagram of the connection between an optical repeater and an end station provided in this embodiment; Figure 6 A schematic diagram of a detection curve provided in this embodiment; Figure 7 Another detection curve schematic diagram provided for this embodiment; Figure 8 A schematic diagram of connections between multiple opposite-end terminals and terminals provided in this embodiment; Fig. 9 A schematic diagram of the structure of a submarine cable fault detection system provided in this embodiment. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, other embodiments obtained by ordinary technicians in this field without making creative work all belong to the protection scope of the present application.

[0022] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0023] In addition, in the present application, directional terms such as "upper", "lower", "inner" and "outer" are defined relative to the orientation of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components placed in the drawings.

[0024] To facilitate understanding of the solution, the following explains the relevant terms: Submarine Optical Fiber Cable: A submarine cable is a communication cable laid on the seabed, used to transmit optical signals between the mainland and islands, and between islands, thereby achieving long-distance communication of voice, data, images and other information. A submarine cable contains multiple optical fibers to increase communication capacity.

[0025] Terminal station: It is the key node connecting the submarine cable system with the land communication network and is the terminal equipment of the submarine cable on land. It is responsible for connecting the information transmitted by the submarine cable to the corresponding network on land and sending the information of the land network to the submarine cable for transmission.

[0026] Repeater (RPT): A device that amplifies and regenerates optical signals. As optical signals will attenuate when transmitted over long distances via submarine cables, repeaters are used to enhance the signal and perform signal shaping and timing processing to correct the distortion and distortion of the signal during transmission.

[0027] Branching Unit (BU): It is used to branch the signal in the submarine cable line into multiple branches to achieve the connection of multiple locations. When the submarine communication network needs to connect communication nodes in multiple islands or coastal cities, the branching unit distributes the signal to different branches, thereby expanding the coverage of the submarine cable system.

[0028] Reconfigurable Optical Add-Drop Multiplexer (ROADM): It can multiplex multiple optical signals of different wavelengths into one optical fiber for transmission. In addition, ROADM can also multiplex the composite optical signal transmitted from the optical fiber and separate the optical signals of each wavelength so that each optical signal can accurately reach the corresponding receiving device.

[0029] Coherent Optical Time-Domain Reflectometer (COTDR): An instrument used for optical fiber link characteristic testing and fault detection. It locates the fault point in the optical fiber by emitting coherent optical pulses into the optical fiber and receiving the reflected optical signals of the optical pulses.

[0030] Network Management System (NMS): is a module for managing submarine cable communication network. The NMS can monitor, configure, diagnose faults and manage performance of various devices, lines and transmitted signals in the submarine cable communication network.

[0031] In the field of submarine communication technology, submarine cables are a key component of communication, which can transmit data and signals between various terminals. Since submarine cables are usually laid on the seabed, they are exposed to a variety of potential destructive factors. For example, special situations such as earthquakes, ship anchors or fishing nets can easily cause damage to submarine cables, which in turn leads to serious impacts such as interruption of transoceanic communications and data loss. Through fault detection, these potential safety hazards can be discovered and the fault location can be located, thereby realizing automatic disaster recovery of the submarine cable system and ensuring normal communication between various terminals.

[0032] The end station uses a coherent optical time domain reflectometer to transmit an optical pulse signal of a specific wavelength to the optical fiber in the submarine cable. During the propagation of the optical signal, due to the Rayleigh scattering principle, the optical signal will be scattered in the submarine cable and generate scattered light. Since the scattered light will have an abnormal optical power at the optical fiber fault point, the end station can determine the location of the fault point in the optical fiber by measuring and analyzing the scattered light. However, since the above process requires multiple transmissions of optical pulse signals and the location of the fault point is detected based on the average value of multiple analysis results, the entire process takes a long time and cannot detect the transmission status of the submarine cable in real time. Therefore, the above method cannot detect submarine cable faults in a timely manner, and thus cannot guarantee the reliability and safety of the operation of the submarine cable system.

[0033] In order to detect the operation of the submarine cable system in real time and automatically locate the fault location and cause of the fault when a submarine cable fails, the embodiment of the present application provides a submarine cable fault detection method, which is applied to a terminal station, such as Figure 1 As shown, the submarine cable fault detection method includes: Step S100: determining whether to perform fault detection on the submarine cable to be detected based on the detection information.

[0034] In an embodiment of the present application, the terminal station includes an open submarine cable access device, wherein the open submarine cable access device is a communication device, exemplarily, such as Figure 2 As shown, the present application provides a schematic diagram of the structure of a communication device 200. The communication device 200 includes: at least one processor 201, at least one memory 202, and at least one communication interface 203. Among them, at least one processor 201, at least one memory 202, and at least one communication interface 203 can be connected through a bus.

[0035] The memory 202 is used to store computer program codes. The processor 201 is used to call the computer program codes stored in the memory 202 to execute the functions of the terminal in the following method embodiment. The communication interface 203 is used to communicate with other communication devices. Exemplarily, the communication interface 203 can communicate in the form of optical fiber communication.

[0036] In the embodiments of the present application, Figure 3 As shown, the terminal station is connected to the opposite terminal station based on the submarine cable to be detected, and the opposite terminal station sends a first signal to the terminal station based on the submarine cable to be detected. Since the first signal will be attenuated during the transmission process, when the first signal reaches the terminal station, a second signal is generated. The terminal station obtains the second signal and performs analysis on the second signal to generate detection information according to the second signal, and then determines whether to perform fault detection on the submarine cable to be detected based on the detection information.

[0037] The detection information includes at least one of a heartbeat signal, optical power, and a signal-to-noise ratio. The terminal generates a detection result based on the detection information, wherein the detection result is used to indicate whether the detection information meets a preset condition. For example, the detection result can be used to indicate whether the terminal receives a heartbeat signal; whether the optical power of the signal received by the terminal meets a preset optical power condition; whether the signal-to-noise ratio of the signal received by the terminal meets a preset signal-to-noise ratio condition, etc.

[0038] In an embodiment of the present application, the network management unit and the terminal station can communicate in real time, wherein the communication method can be an embedded control channel, a virtual private network, and satellite communication, etc. The terminal station sends the detection result to the network management unit. The detection result can reflect the operating status of the submarine cable to be detected. According to the detection result and in combination with the pre-set submarine cable topology structure, the network management unit can analyze whether the submarine cable to be detected has a fault and generate a fault detection identifier. In this way, the network management unit can detect the operating status of the submarine cable to be detected in real time, and then promptly discover the fault of the submarine cable to be detected. Among them, the fault detection identifier includes a detection state and a non-detection state. The terminal station obtains the fault detection identifier returned by the network management unit and determines whether to perform fault detection on the submarine cable to be detected.

[0039] The terminal performs detection on the received second signal to generate a detection result, and based on the real-time communication between the terminal and the network management unit, sends the detection result to the network management unit to determine whether to perform fault detection on the submarine cable to be detected. Based on the above method, real-time detection of the submarine cable to be detected can be achieved. When a fault occurs in the submarine cable to be detected, a fault detection mark of the detection status is generated, thereby automatically locating the fault location and cause of the submarine cable to be detected.

[0040] In an embodiment of the present application, the first signal sent by the opposite terminal station includes a first heartbeat signal. The first heartbeat signal is a signal generated by amplitude modulating the total optical power of the first signal. The modulation frequency of the first heartbeat signal is greater than a preset frequency threshold to reduce the attenuation of the first heartbeat signal. The modulation depth of the first heartbeat signal is less than a preset threshold value so that the signal-to-noise ratio of the first signal is not reduced during the transmission of the first heartbeat signal.

[0041] Exemplarily, the preset frequency threshold may be the cutoff frequency of an erbium doped fiber amplifier (EDFA). The cutoff frequency of an erbium doped fiber amplifier refers to the boundary frequency at which the output signal energy begins to drop significantly in the frequency response characteristics. Figure 4 As shown, the signal corresponding to the periodic fluctuation of the optical power represents the modulated first heartbeat signal, the modulation frequency of the first heartbeat signal is 200 kHz, and the modulation depth of the first heartbeat signal is 2%.

[0042] In an embodiment of the present application, an open submarine cable access device of the terminal includes a feedback component, and the open submarine cable access device calls the feedback component to enable the feedback component to parse the second signal. The feedback component detects whether the second signal includes a second heartbeat signal, wherein the second heartbeat signal is a signal that arrives at the terminal after the first heartbeat signal is transmitted based on the submarine cable to be detected.

[0043] It should be noted that the feedback component is also used to send a heartbeat signal. Exemplarily, the open submarine cable access device of the opposite terminal includes a feedback component, and the open submarine cable access device calls the feedback component to enable the feedback component to send a first heartbeat signal.

[0044] In an embodiment of the present application, the terminal generates a detection result according to whether the second signal includes the second heartbeat signal, and the detection result can reflect whether the signal transmission between the terminal and the opposite terminal is normal. When the second signal includes the second heartbeat signal, the terminal generates a first detection result, and the first detection result is used to characterize that the second heartbeat signal is in a normal transmission state. When the second signal does not include the second heartbeat signal, the terminal generates a second detection result, and the detection result is used to characterize that the second heartbeat signal is in an abnormal transmission state.

[0045] In this way, the terminal generates a detection result according to whether the second signal includes the second heartbeat signal, and sends the detection result to the network management unit, so that the operation status of the submarine cable to be detected can be detected in real time. When the second signal does not include the second heartbeat signal, it indicates that the signal of the opposite terminal has not been normally transmitted to the terminal. The network management unit generates a fault detection mark in combination with the pre-set submarine cable topology structure to perform fault detection on the submarine cable to be detected, and then determine the fault location and fault type.

[0046] In the embodiment of the present application, the submarine cable equipment manual will provide the optical power range under normal working conditions. Therefore, the terminal can determine whether the signal of the opposite terminal is normally transmitted to the terminal by obtaining the optical power of the second signal. For example, when the optical power of the second signal drops below the preset optical power threshold, the submarine cable to be detected may be faulty. The terminal generates a detection result based on the optical power of the second signal and sends the detection result to the network management unit, so that the network management unit generates a fault detection mark in combination with the preset submarine cable topology.

[0047] When the optical power is less than the preset optical power threshold, the end station generates a third detection result, and the third detection result is used to indicate that the second signal does not meet the preset optical power condition. When the optical power is greater than or equal to the preset optical power threshold, the end station generates a fourth detection result, and the fourth detection result is used to indicate that the second signal meets the preset optical power condition.

[0048] In this way, the terminal station detects the operating status of the submarine cable to be detected in real time through the optical power of the second signal, can promptly discover the fault of the submarine cable to be detected, and improve the stability of the submarine cable system.

[0049] In the embodiment of the present application, since the marine environment in which the submarine cable is located will introduce certain noise, such as the flow of seawater, temperature changes, marine biological activities, etc., the signal-to-noise ratio fluctuation range is relatively stable during the normal operation of the submarine cable system. The submarine cable equipment manual will record the signal-to-noise ratio range of the submarine cable under normal working conditions. The signal-to-noise ratio (Optical Signal-to-Noise Ratio, OSNR) is used to measure the intensity of the signal power relative to the noise power during the transmission of the optical signal. When the signal-to-noise ratio of the second signal drops to the preset signal-to-noise ratio threshold, it indicates that the submarine cable to be detected may be faulty. The terminal obtains the signal-to-noise ratio of the second signal and generates a detection result based on the signal-to-noise ratio.

[0050] When the signal-to-noise ratio is greater than or equal to the preset signal-to-noise ratio threshold, the terminal generates a fifth detection result, and the fifth detection result is used to indicate that the second signal meets the preset signal-to-noise ratio condition. When the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the terminal generates a sixth detection result, and the sixth detection result is used to indicate that the second signal does not meet the preset signal-to-noise ratio condition.

[0051] In this way, the terminal station can realize real-time detection of the submarine cable to be detected at low cost according to at least one of the heartbeat signal, optical power and signal-to-noise ratio. The terminal station sends the detection result to the network management unit and obtains the fault detection identifier returned by the network management unit, so as to automatically perform fault detection on the submarine cable to be detected when necessary, so as to ensure the safety and reliability of the operation of the submarine cable system.

[0052] In an embodiment of the present application, the network management unit generates a fault detection identifier according to the detection result, and when the fault detection identifier is in a detection state, determines to perform fault detection on the submarine cable to be detected, and when the fault detection identifier is in a non-detection state, determines not to perform fault detection on the submarine cable to be detected.

[0053] Step S2011: When performing fault detection on the submarine cable to be detected, a pulse signal is sent to the submarine cable to be detected, and a returned scattered light signal is received.

[0054] In an embodiment of the present application, the open submarine cable access equipment in the terminal station also includes a coherent optical time domain reflectometer. The open submarine cable access equipment calls the coherent optical time domain reflectometer to enable the coherent optical time domain reflectometer to send a pulse signal to the submarine cable to be detected based on a preset time period and receive a returned scattered light signal.

[0055] In the embodiment of the present application, an underwater device is included between the terminal and the opposite terminal, and the underwater device may include at least one of an optical repeater, a splitter, and a reconfigurable optical add / drop multiplexing device, and the terminal and the underwater device are connected based on the submarine cable to be detected. Figure 5 As shown, an optical repeater is included between the end station and the opposite end station, and the optical repeater is used to amplify the transmitted optical signal.

[0056] Exemplarily, the end station uses a coherent optical time domain reflectometer to send a pulse signal to the submarine cable to be tested. When the pulse signal reaches the optical repeater, it is amplified and generates backscattered light. The backscattered light passes through the optical repeater's OI loopback path (Optical-In loopback path) and returns to the coherent optical time domain reflectometer, so that the coherent optical time domain reflectometer receives the returned scattered light signal. The optical repeater's OI loopback path is a test path inside the optical repeater, which introduces the optical signal from the optical interface, then passes through the loopback path inside the device and returns to the optical interface.

[0057] Step S2012: Generate a detection curve according to the pulse signal and the scattered light signal.

[0058] In the embodiment of the present application, the terminal uses a coherent optical time domain reflectometer to perform coherent processing on the pulse signal and the scattered light signal to generate a coherent signal, wherein the coherent signal includes time information and optical power information. The coherent optical time domain reflectometer generates a detection curve according to the correspondence between the time information and the optical power information.

[0059] Exemplarily, the detection curve generated by the coherent optical time domain reflectometer is as follows Figure 6 As shown, Figure 6 The horizontal axis represents the time corresponding to the coherent signal, and the vertical axis represents the optical power corresponding to the coherent signal. Figure 6The change of the coherent signal of the detection curve can generate the fault location and fault type of the submarine cable to be detected.

[0060] Step S2013: Generate the fault location and fault type according to the detection curve.

[0061] In the process of generating the fault location and fault type according to the detection curve at the terminal, the coherent optical time domain reflectometer first marks the fault point based on the detection curve, wherein the optical power information corresponding to the fault point is lower than the preset standard threshold.

[0062] For example, Figure 6 As shown, the optical power at point A suddenly drops below the preset standard threshold, and point A is marked as a fault point.

[0063] For example, Figure 7 As shown, the optical power at point B drops below the preset standard threshold, and point B is marked as a fault point.

[0064] Further, the terminal obtains the fault time information, which is the time information corresponding to the fault point. The terminal calculates the fault location according to the fault time information. For example, the time information corresponding to point A is T1, and the speed of light c is multiplied by the time information T1 to obtain the fault point distance, where the fault point distance is the distance between the terminal and the fault point. Based on this, the fault location is calculated according to the fault time information.

[0065] In an embodiment of the present application, the fault types include cable break faults and non-cable break faults. The terminal obtains reference time information and obtains a reference fault point based on the reference time information. The difference between the reference time information and the fault time information is a preset time difference. The reference time information is after the fault time information. The reference fault point is the point corresponding to the reference time information in the detection curve. The terminal calculates the difference between the optical power corresponding to the fault point and the optical power corresponding to the reference fault point to obtain the fault optical power difference. The fault optical power difference can be used to characterize the speed at which the optical power at the fault point decreases. When the fault optical power difference is greater than the preset optical power difference, it characterizes that the speed at which the optical power at the fault point decreases is large, and the terminal marks the fault type as a cable break fault. When the fault optical power difference is less than or equal to the preset optical power difference, it characterizes that the speed at which the optical power at the fault point decreases is small, and the terminal marks the fault type as a non-cable break fault.

[0066] For example, Figure 6 As shown, the fault time information corresponding to point A is T1, and the preset time difference is , the reference time information is T2, and the terminal obtains the reference time information T2 corresponding to the reference fault point C. The difference in optical power between point A and point C is greater than the preset optical power difference, indicating that the submarine cable to be detected has a cable break fault.

[0067] For example, Figure 7As shown, the fault time information corresponding to point B is T3, and the preset time difference is , the reference time information is T4, the terminal obtains the reference time information T4 corresponding to the reference fault point D, and the optical power difference between point B and point D is less than the preset optical power difference, indicating that a non-cable break fault occurs in the submarine cable to be detected.

[0068] It should be understood that the embodiments of the present application do not specifically limit the equipment for detecting the fault location and fault type of the submarine cable. For example, the equipment for detecting the fault location and fault type of the submarine cable may be an optical time domain reflectometer or an optical frequency domain reflectometer, as long as the fault location and fault type of the submarine cable can be located.

[0069] Step S2021: When fault detection is not performed on the submarine cable to be detected, detection information is continuously acquired and a fault detection identifier is updated; when fault detection needs to be performed on the submarine cable to be detected, the fault location and fault type are detected.

[0070] It should be noted that, in the embodiment of the present application, the number of the opposite terminal station may be one or more, and at least one submarine cable to be detected is included between the terminal station and the opposite terminal station. Figure 8 As shown, the first terminal station communicates with the second terminal station through the first branch and the second branch, the first terminal station communicates with the third terminal station through the first branch and the first reconfigurable optical add-drop multiplexer, and the second terminal station communicates with the fourth terminal station through the second branch and the second reconfigurable optical add-drop multiplexer. Among them, the opposite terminal stations of the first terminal station are the second terminal station and the third terminal station. The first terminal station, the second terminal station, the third terminal station and the fourth terminal station are connected to a unified network management unit. The network management unit summarizes the detection information of each terminal station and the pre-set submarine cable topology structure, analyzes the span where the fault is located, and marks the fault detection identification of the faulty submarine cable with the detection status. And, in the case where it is necessary to perform fault detection on the submarine cable to be detected, the terminal station sends a pulse signal to detect the fault location and fault type.

[0071] Exemplarily, the network management unit marks the submarine cable 903 to be detected as being in a detection state, and the first end station and the third end station use a coherent optical time domain reflectometer to analyze the fault location and fault type, thereby completing the fault detection.

[0072] It should be understood that the method provided in the embodiment of the present application can also perform detection on underwater equipment. When the terminal generates the fault location and fault type according to the detection curve, if the location corresponding to the fault location is the underwater equipment, it is determined that the underwater equipment has a fault.

[0073] It can be seen from the above technical solution that the present application provides a submarine cable fault detection method, which can generate detection information based on the signal received by the terminal, and detect the transmission status of the submarine cable to be detected in real time according to at least one detection information of the heartbeat signal, optical power and signal-to-noise ratio, and perform fault detection on the submarine cable to be detected when the detection result is abnormal, send a pulse signal to the submarine cable to be detected, and receive the returned scattered light signal to analyze the fault location and fault type of the submarine cable to be detected. The submarine cable fault detection method provided by the present application can perform real-time detection of the submarine cable and improve the efficiency and accuracy of submarine cable fault detection.

[0074] Based on the above-mentioned embodiment, a submarine cable fault detection method is provided. Some embodiments of the present application also provide a submarine cable fault detection system. Fig. 9 , the submarine cable fault detection system includes: an end station 901, an opposite end station 902, a submarine cable to be detected 903 and a network management unit 904. The end station 901 is connected to the opposite end station 902 based on the submarine cable to be detected 903, and the network management unit 904 communicates with the end station 901 to provide a fault detection identifier to the end station 901, and the fault detection identifier is used to indicate whether to perform fault detection on the submarine cable to be detected. Send a signal. The submarine cable to be detected 903 is configured to: connect the end station 901 and the opposite end station 902, so that the end station 901 receives the signal sent by the opposite end station 902. The end station 901 is configured to: execute the submarine cable fault detection method described in the first aspect. The network management unit 904 is configured to: obtain the detection result sent by the end station 901, and generate a fault detection identifier according to the detection result, and the fault detection identifier includes a detection state and a non-detection state.

[0075] The effects of the above system in the process of executing the method can be found in the description of the above method, which will not be repeated here.

[0076] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope of the present application is indicated by the claims.

[0077] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for detecting a submarine cable fault, characterized in that: Applied to a terminal station, the submarine cable fault detection method comprises: Determine whether to perform fault detection on the submarine cable to be detected based on detection information, the detection information is used to detect the transmission status of the submarine cable to be detected in real time, the detection information is generated based on the signal received by the terminal, and the detection information includes at least one of a heartbeat signal, optical power and a signal-to-noise ratio; In the case of performing fault detection on the submarine cable to be detected, a pulse signal is sent to the submarine cable to be detected, and a returned scattered light signal is received, and a detection curve is generated according to the pulse signal and the scattered light signal; A fault location and a fault type are generated according to the detection curve.

2. The method for detecting submarine cable faults according to claim 1, characterized in that: The determining whether to perform fault detection on the submarine cable to be detected based on the detection information comprises: Acquire the detection information, and generate a detection result based on the detection information, wherein the detection result is used to indicate whether the detection information meets a preset condition; The detection result is sent to a network management unit, and a fault detection identifier returned by the network management unit is obtained, wherein the fault detection identifier includes a detection state and a non-detection state, and the network management unit is used to generate the fault detection identifier of the submarine cable to be detected according to the detection result and a preset submarine cable topology structure; Determine whether to perform fault detection on the submarine cable to be detected according to the fault detection identifier.

3. The method for detecting submarine cable faults according to claim 2, characterized in that: The acquiring the detection information and generating a detection result based on the detection information includes: Acquire a second signal, where the second signal is a signal of the first signal arriving at the terminal after being transmitted based on the submarine cable to be detected, the first signal is a signal sent by the opposite terminal, the first signal includes a first heartbeat signal, the first heartbeat signal is a signal generated by amplitude modulating the total optical power of the first signal, the modulation frequency of the first heartbeat signal is greater than a preset frequency threshold, and the modulation depth of the first heartbeat signal is less than a preset threshold; Parsing the second signal to detect whether the second signal includes a second heartbeat signal, where the second heartbeat signal is a signal of the first heartbeat signal that arrives at the terminal after being transmitted through the submarine cable to be detected; In a case where the second signal includes the second heartbeat signal, generating a first detection result, wherein the first detection result is used to indicate that the second heartbeat signal is in a normal transmission state; In the case that the second signal does not include the second heartbeat signal, a second detection result is generated, where the second detection result is used to indicate that the second heartbeat signal is in an abnormal transmission state.

4. The method for detecting submarine cable faults according to claim 3, characterized in that: The terminal station includes an open submarine cable access device, the open submarine cable access device includes a feedback component, and the open submarine cable access device calls the feedback component to enable the feedback component to detect whether the second signal includes a second heartbeat signal.

5. The method for detecting submarine cable faults according to claim 3, characterized in that: The acquiring the detection information and generating a detection result based on the detection information includes: Acquiring the optical power of the second signal; When the optical power is less than a preset optical power threshold, generating a third detection result, wherein the third detection result is used to indicate that the second signal does not meet the preset optical power condition; In a case where the optical power is greater than or equal to a preset optical power threshold, a fourth detection result is generated, where the fourth detection result is used to indicate that the second signal meets a preset optical power condition.

6. The method for detecting submarine cable faults according to claim 5, characterized in that: The acquiring the detection information and generating a detection result based on the detection information includes: Acquire a signal-to-noise ratio of the second signal, where the signal-to-noise ratio is used to characterize a ratio of the optical power to the noise power; When the signal-to-noise ratio is greater than or equal to a preset signal-to-noise ratio threshold, generating a fifth detection result, wherein the fifth detection result is used to indicate that the second signal meets a preset signal-to-noise ratio condition; When the signal-to-noise ratio is less than a preset signal-to-noise ratio threshold, a sixth detection result is generated, where the sixth detection result is used to indicate that the second signal does not meet a preset signal-to-noise ratio condition.

7. The method for detecting submarine cable faults according to claim 4, characterized in that: The open submarine cable access device also includes a coherent optical time domain reflectometer, and the open submarine cable access device calls the coherent optical time domain reflectometer so that the coherent optical time domain reflectometer sends the pulse signal to the submarine cable to be detected based on a preset time period and receives the returned scattered light signal.

8. The method for detecting submarine cable faults according to claim 1, characterized in that: The generating a detection curve according to the pulse signal and the scattered light signal comprises: Performing coherent processing on the pulse signal and the scattered light signal to generate a coherent signal, wherein the coherent signal includes time information and optical power information; A detection curve is generated according to the correspondence between the time information and the optical power information.

9. The method for detecting submarine cable faults according to claim 8, characterized in that: The fault type includes a cable break fault and a non-cable break fault, and the generating of the fault position and the fault type according to the detection curve includes: Marking a fault point based on the detection curve, where the optical power information corresponding to the fault point is lower than a preset standard threshold; Obtaining fault time information, and calculating the fault location according to the fault time information, wherein the fault time information is time information corresponding to the fault point; Acquire reference time information, and acquire a reference fault point based on the reference time information, wherein the difference between the reference time information and the fault time information is a preset time difference, the reference time information is after the fault time information, and the reference fault point is a point in the detection curve corresponding to the reference time information; Calculating the difference between the optical power corresponding to the fault point and the optical power corresponding to the reference fault point to obtain a fault optical power difference; When the fault optical power difference is greater than a preset optical power difference, marking the fault type as a cable break fault; When the fault optical power difference is less than or equal to the preset optical power difference, the fault type is marked as a non-cable break fault.

10. The method for detecting submarine cable faults according to claim 3, characterized in that: The number of the opposite terminal station is one or more, and at least one submarine cable to be detected is included between the terminal station and the opposite terminal station.

11. The method for detecting submarine cable faults according to claim 3, characterized in that: An underwater device is included between the terminal station and the opposite terminal station, and the underwater device includes at least one of an optical repeater, a branching device and a reconfigurable optical add-drop multiplexing device. The terminal station and the underwater device are connected based on the submarine cable to be detected.

12. A submarine cable fault detection system, characterized in that: include: End station, opposite end station, submarine cable to be tested and network management unit; The terminal is connected to the opposite terminal based on the submarine cable to be detected, and the network management unit communicates with the terminal to provide a fault detection identifier to the terminal, wherein the fault detection identifier is used to indicate whether to perform fault detection on the submarine cable to be detected; The terminal is configured to: execute the submarine cable fault detection method according to any one of claims 1-11.

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