Optical fiber fault locating method, system, device, and vehicle

Abstract

Embodiments of the present application provide a method, system and device for fault positioning of an optical fiber and a vehicle. The method is applied to an optical line terminal. The method sends a first probe frame to a to-be-detected link in a vehicle-mounted optical communication at a preset management wavelength. The first probe frame is a bit error probe frame and / or a delay probe frame. The management wavelength is different in size from a service wavelength used for service data transmission. The to-be-detected link includes at least two first nodes. The first node includes a connection box or an optical distribution node. The method determines whether the to-be-detected link has a fault according to a first response information corresponding to the to-be-detected link. If the to-be-detected link has a fault, the method determines a faulty optical fiber segment in the to-be-detected link according to a second response information corresponding to a loopback frame sent to the to-be-detected link. The scheme realizes accurate positioning of the faulty optical fiber segment without affecting service communication.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, system, device and vehicle for locating optical fiber faults. Background Technology

[0002] As the core communication infrastructure of intelligent vehicles, the stability and maintainability of in-vehicle optical communication networks directly affect the overall vehicle performance and user safety, especially during vehicle use, vehicle debugging, and transportation and storage.

[0003] In existing technologies, the management plane and service plane of optical communication networks usually share the same optical channel to achieve control and management of various nodes such as junction boxes or optical distribution nodes.

[0004] However, the above methods cannot accurately locate faulty fiber segments without affecting business communications. Summary of the Invention

[0005] This application provides a method, system, device, and vehicle for locating optical fiber faults, which achieves the technical effect of accurately locating faulty optical fiber segments without affecting business communication.

[0006] In a first aspect, embodiments of this application provide a method for locating optical fiber faults, applied to an optical line terminal in a vehicle, the method comprising:

[0007] A first detection frame is sent to the link to be tested in the vehicle-mounted optical communication at a preset management wavelength. The first detection frame is a bit error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be tested includes at least two first nodes, and the first nodes include a junction box or an optical distribution node.

[0008] Based on the first response information received corresponding to the link to be tested, it is determined whether the link to be tested is faulty;

[0009] If the link under test is faulty, the faulty fiber segment in the link under test is determined according to the second response information corresponding to the loopback frame sent to the link under test.

[0010] In one or more embodiments, determining the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test includes:

[0011] Starting from the optical line terminal, and based on the physical topology of the link to be detected, the loopback frames are sent sequentially to the first node from near to far.

[0012] For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, then the fiber segment at the first node is determined to be the faulty fiber segment.

[0013] In one or more embodiments, the first preset condition includes at least one of the following:

[0014] The second response information indicates that it is empty;

[0015] The second response information indicates that the real-time attenuation value is greater than or equal to the preset first value corresponding to the first node;

[0016] The second response information indicates that the real-time delay value is greater than or equal to the preset second value corresponding to the first node.

[0017] In one or more embodiments, the first detection frame is the bit error detection frame;

[0018] Accordingly, sending the first probe frame to the link to be tested in the vehicle-mounted optical communication includes:

[0019] The first probe frame is sent to at least two first nodes in the link to be detected.

[0020] In one or more embodiments, the first response information includes: error response information returned based on the error detection frame;

[0021] Accordingly, determining whether the link under test is faulty based on the first response information received from the link under test includes:

[0022] Obtain the error response information returned by each first node for the error detection frame;

[0023] For each first node, if the bit error rate indicated in the error response information corresponding to the first node is greater than or equal to the bit error rate threshold corresponding to the first node, then it is determined that the link to be detected has a fault.

[0024] For all first nodes, if the bit error rate indicated in the error response information corresponding to all first nodes is less than the bit error rate threshold corresponding to the corresponding first node, then it is determined that the link to be tested has no fault.

[0025] In one or more embodiments, the first detection frame is the delayed detection frame;

[0026] Accordingly, sending the first probe frame to the link to be tested in the vehicle-mounted optical communication includes:

[0027] The delay detection frame is sent to at least two first nodes in the link to be detected.

[0028] In one or more embodiments, the first response information includes: delayed response information returned based on the delayed probe frame;

[0029] Accordingly, determining whether the link under test is faulty based on the first response information received from the link under test includes:

[0030] Obtain the delay response information returned by each first node in response to the delay probe frame;

[0031] For each first node, if the delay value indicated in the delay response information corresponding to the first node is greater than or equal to the delay threshold corresponding to the first node, then it is determined that the link to be detected is faulty.

[0032] For all first nodes, if the delay value indicated in the delay response information corresponding to all first nodes is less than the delay threshold corresponding to the corresponding first node, then it is determined that the link to be tested is not faulty.

[0033] In one or more embodiments, before sending the first probe frame to the link to be detected in the vehicular optical communication at a preset management wavelength, the method further includes:

[0034] For each communication link in the vehicle-mounted optical communication, first performance data of the communication link is obtained, the first performance data including: cumulative attenuation value and / or response missing data;

[0035] Based on the first performance data, determine whether the communication link is the link to be detected.

[0036] In one or more embodiments, the first performance data includes: a cumulative attenuation value;

[0037] Accordingly, determining whether the communication link is the link to be detected based on the first performance data includes:

[0038] If the cumulative attenuation value is greater than or equal to a preset attenuation value threshold, then the communication link is identified as the link to be detected.

[0039] In one or more embodiments, the first performance data includes: response missing data;

[0040] If the number of consecutive missing response data indicates that the number of missing data is greater than a preset threshold, then the communication link is identified as the link to be detected.

[0041] In one or more embodiments, prior to acquiring the first performance data of the communication link, the method further includes:

[0042] Link tracking frames are periodically broadcast to at least one passive optical network port of the optical line terminal at the management wavelength.

[0043] Obtain the third response information returned based on the link tracing frame. The third response information includes: the hop count of each node, and the nodes include: a junction box or an optical distribution node.

[0044] Based on the hop count of each node, at least one communication link is constructed.

[0045] In one or more embodiments, the third response information further includes: the attenuation value of each node;

[0046] Accordingly, the method further includes:

[0047] The attenuation threshold is constructed based on the attenuation values ​​of each node in the communication link.

[0048] In one or more embodiments, the method further includes:

[0049] If the link to be tested is faulty, obtain the target diagnostic information involved in the fault location of the link to be tested;

[0050] The diagnostic data corresponding to different diagnostic access permissions are determined from the target diagnostic information.

[0051] In one or more embodiments, the management wavelength includes at least one of 1310 nm, 1270 nm, and 1330 nm; the service wavelength includes at least one of 1490 nm and 1550 nm.

[0052] The timing of sending the operation and maintenance management frame based on the management wavelength is located in a preset time slot interval, where the time slot interval is an idle time slot not occupied by the service data transmission. The operation and maintenance management frame includes at least one of the following: error detection frame, delay detection frame, link tracing frame, and loopback frame.

[0053] Secondly, embodiments of this application provide a fault location device for optical fibers, applied to an optical line terminal in a vehicle, the device comprising:

[0054] The transmitting module is used to transmit a first detection frame to the link to be tested in the vehicle-mounted optical communication at a preset management wavelength. The first detection frame is a bit error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be tested includes at least two first nodes, and the first nodes include a junction box or an optical distribution node.

[0055] The first determining module is used to determine whether the link under test is faulty based on the first response information received corresponding to the link under test;

[0056] The second determining module is used to determine the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test when the link under test has a fault.

[0057] In one or more embodiments, the second determining module determines the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test, specifically for:

[0058] Starting from the optical line terminal, and based on the physical topology of the link to be detected, the loopback frames are sent sequentially to the first node from near to far.

[0059] For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, then the fiber segment at the first node is determined to be the faulty fiber segment.

[0060] In one or more embodiments, the first preset condition includes at least one of the following:

[0061] The second response information indicates that it is empty;

[0062] The second response information indicates that the real-time attenuation value is greater than or equal to the preset first value corresponding to the first node;

[0063] The second response information indicates that the real-time delay value is greater than or equal to the preset second value corresponding to the first node.

[0064] In one or more embodiments, the first detection frame is the bit error detection frame;

[0065] Accordingly, the sending module sends a first probe frame to the link to be tested in the vehicle-mounted optical communication, specifically for:

[0066] The first probe frame is sent to at least two first nodes in the link to be detected.

[0067] In one or more embodiments, the first response information includes: error response information returned based on the error detection frame;

[0068] Accordingly, the first determining module determines whether the link under test is faulty based on the first response information received corresponding to the link under test, specifically for:

[0069] Obtain the error response information returned by each first node for the error detection frame;

[0070] For each first node, if the bit error rate indicated in the error response information corresponding to the first node is greater than or equal to the bit error rate threshold corresponding to the first node, then it is determined that the link to be detected has a fault.

[0071] For all first nodes, if the bit error rate indicated in the error response information corresponding to all first nodes is less than the bit error rate threshold corresponding to the corresponding first node, then it is determined that the link to be tested has no fault.

[0072] In one or more embodiments, the first detection frame is the delayed detection frame;

[0073] Accordingly, the sending module sends a first probe frame to the link to be tested in the vehicle-mounted optical communication, specifically for:

[0074] The delay detection frame is sent to at least two first nodes in the link to be detected.

[0075] In one or more embodiments, the first response information includes: delayed response information returned based on the delayed probe frame;

[0076] Accordingly, the first determining module determines whether the link under test is faulty based on the first response information received corresponding to the link under test, specifically for:

[0077] Obtain the delay response information returned by each first node in response to the delay probe frame;

[0078] For each first node, if the delay value indicated in the delay response information corresponding to the first node is greater than or equal to the delay threshold corresponding to the first node, then it is determined that the link to be detected is faulty.

[0079] For all first nodes, if the delay value indicated in the delay response information corresponding to all first nodes is less than the delay threshold corresponding to the corresponding first node, then it is determined that the link to be tested is not faulty.

[0080] In one or more embodiments, before sending the first probe frame to the link to be detected in the vehicular optical communication at a preset management wavelength, the first determining module is further configured to:

[0081] For each communication link in the vehicle-mounted optical communication, first performance data of the communication link is obtained, the first performance data including: cumulative attenuation value and / or response missing data;

[0082] Based on the first performance data, determine whether the communication link is the link to be detected.

[0083] In one or more embodiments, the first performance data includes: a cumulative attenuation value;

[0084] Accordingly, the first determining module, based on the first performance data, determines whether the communication link is the link to be detected, specifically for:

[0085] If the cumulative attenuation value is greater than or equal to a preset attenuation value threshold, then the communication link is identified as the link to be detected.

[0086] In one or more embodiments, the first performance data includes: response missing data;

[0087] If the number of consecutive missing response data indicates that the number of missing data is greater than a preset threshold, then the communication link is identified as the link to be detected.

[0088] In one or more embodiments, before acquiring the first performance data of the communication link, the first determining module is further configured to:

[0089] Link tracking frames are periodically broadcast to at least one passive optical network port of the optical line terminal at the management wavelength.

[0090] Obtain the third response information returned based on the link tracing frame. The third response information includes: the hop count of each node, and the nodes include: a junction box or an optical distribution node.

[0091] Based on the hop count of each node, at least one communication link is constructed.

[0092] In one or more embodiments, the third response information further includes: the attenuation value of each node;

[0093] Accordingly, the first determining module is further configured to:

[0094] The attenuation threshold is constructed based on the attenuation values ​​of each node in the communication link.

[0095] In one or more embodiments, the first determining module is further configured to:

[0096] If the link to be tested is faulty, obtain the target diagnostic information involved in the fault location of the link to be tested;

[0097] The diagnostic data corresponding to different diagnostic access permissions are determined from the target diagnostic information.

[0098] In one or more embodiments, the management wavelength includes at least one of 1310 nm, 1270 nm, and 1330 nm; the service wavelength includes at least one of 1490 nm and 1550 nm.

[0099] The timing of sending the operation and maintenance management frame based on the management wavelength is located in a preset time slot interval, where the time slot interval is an idle time slot not occupied by the service data transmission. The operation and maintenance management frame includes at least one of the following: error detection frame, delay detection frame, link tracing frame, and loopback frame.

[0100] Thirdly, embodiments of this application provide a fault location system for optical fiber, the system comprising: an optical line terminal and at least one node directly or indirectly connected to the terminal, the node comprising: a junction box or an optical distribution node;

[0101] The optical line terminal is used to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0102] Fourthly, embodiments of this application provide a vehicle, the vehicle comprising: an optical line terminal for performing the first aspect and / or various possible implementations of the first aspect;

[0103] Or, the fiber optic fault location system described in the third aspect.

[0104] Fifthly, embodiments of this application provide an optical line terminal, including: a memory and a processor;

[0105] The memory stores computer-executed instructions;

[0106] The processor executes computer execution instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0107] In a sixth aspect, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0108] In a seventh aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0109] The fiber optic fault location method, system, device, and vehicle provided in this application embodiment are applied to an optical line terminal. The method involves sending a first probe frame (error detection frame and / or delay detection frame) to a link under test in a vehicle-mounted optical communication system at a preset management wavelength. The management wavelength differs from the service wavelength used for data transmission. The link under test includes at least two first nodes, each including a junction box or optical distribution node. Based on the first response information received from the link under test, it is determined whether the link under test is faulty. If the link under test is faulty, the faulty fiber segment in the link under test is determined based on the second response information corresponding to a loopback frame sent to the link under test. This technical solution fundamentally avoids mutual interference between fault detection signals and service data transmission by sending probe frames using a management wavelength independent of the service wavelength, thus achieving real-time perception of link status without affecting normal communication. Simultaneously, by first screening the entire link using error detection frames or delay detection frames, the existence of faults can be quickly determined, avoiding the inefficiency of segment-by-segment troubleshooting. Once a fault is confirmed, the fault location granularity is refined from the link level to the specific fiber segment through the response information of the loopback frame. This solves the technical challenge of existing methods, which cannot distinguish between service signals and detection signals and lack a segmented location mechanism, making it difficult to accurately locate faulty fiber segments without interrupting services. Attached Figure Description

[0110] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0111] Figure 1 A block diagram of the vehicle-mounted optical communication control management plane and diagnostic system provided in the embodiments of this application;

[0112] Figure 2 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 1 ;

[0113] Figure 3 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 2 ;

[0114] Figure 4 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 3 ;

[0115] Figure 5 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 4 ;

[0116] Figure 6A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 5 ;

[0117] Figure 7 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 6 ;

[0118] Figure 8 A schematic diagram of the structure of the optical fiber fault location system provided in the embodiments of this application;

[0119] Figure 9 A schematic diagram of the structure of the optical fiber fault location device provided in the embodiments of this application;

[0120] Figure 10 This is a schematic diagram of the structure of an optical line terminal provided in an embodiment of this application.

[0121] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0122] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0123] As the core communication infrastructure of intelligent vehicles, the stability and maintainability of in-vehicle optical communication networks directly affect the performance of the vehicle and the safety of users.

[0124] Especially during the vehicle production and commissioning phase, engineers need to configure the parameters of each Optical Distribution Node (ODN) in real time through precise control and management, and monitor the link status. During transportation and storage, the physical integrity of the optical link must be ensured to avoid communication interruptions caused by vibration or environmental interference. During the user phase, the vehicle system needs to continuously diagnose link quality (such as bit error rate and latency) online to ensure the reliability of critical services such as autonomous driving and high-precision map transmission. In after-sales maintenance scenarios, quickly locating and repairing faulty fiber segments is key to reducing maintenance costs and improving user satisfaction.

[0125] Existing vehicle-mounted optical communication systems generally use a single optical channel to transmit service messages and management messages simultaneously, which makes the management plane easily congested by high-priority service flows, and the upper limit of management response delay is uncontrollable.

[0126] Such solutions typically rely on the main controller to centrally forward management frames, but lack end-to-end link-level operation management and maintenance (e.g., Operations Administration and Maintenance, OAM) mechanisms, resulting in the following technical problems:

[0127] 1) The shared channel between the management plane and the business plane leads to uncontrollable response delays: Existing technologies do not physically isolate the management plane from the business plane. When business emergencies occur, management messages are easily blocked, resulting in unlimited delays in operations such as registration, configuration, and alarms, which affects the real-time performance of the system.

[0128] 2) Lack of business-aware online diagnostic capabilities: Existing solutions cannot accurately measure key performance indicators such as link connectivity, bit error rate (BER), and latency without affecting business transmission, resulting in delayed fault detection;

[0129] 3) The fault location granularity is too coarse and cannot be accurate down to the fiber segment: Existing technology can only locate the fault at the ODN level and cannot further identify the specific faulty fiber segment, resulting in low maintenance efficiency and the risk of misjudgment.

[0130] Accordingly, in response to the technical problems existing in the prior art, the inventors of this application have the following concept: The inventors have discovered that: the business channel and the management channel can be forcibly separated at the physical layer by means of wavelength division multiplexing (WDM). Multiplexing (WDM) filters separate optical waves, fundamentally avoiding spectral conflicts with service data, thus creating an interference-free dedicated inspection channel for online detection. Based on this physical isolation, fault diagnosis is further broken down into two progressive stages: coarse screening and precise location. First, end-to-end probe frames (error / delay) are used to conduct a comprehensive health check of the entire link, quickly determining the presence of anomalies with extremely low signaling overhead, avoiding the resource waste caused by indiscriminate polling of each node. Once a link anomaly is confirmed, a loopback frame is triggered specifically. Utilizing the characteristic of this frame returning at a specific node (connection box or optical distribution node), the fault range is converged from the entire link to a specific fiber segment between two adjacent first nodes. This solves the pain point of existing methods, which lack independent detection wavelengths and segmented loopback mechanisms, requiring segment-by-segment inspection during service downtime or after service interruption. Ultimately, accurate location of faulty fiber segments is achieved without affecting service communication.

[0131] Based on the above technical concept, Figure 1 This is a block diagram of the vehicle-mounted optical communication control management plane and diagnostic system provided in the embodiments of this application. With reference to this block diagram, the optical fiber fault location method provided in the embodiments of this application will be briefly described.

[0132] like Figure 1 As shown, it may include: an Optical Line Terminal (OLT) / OAM platform, a cockpit OLT / OAM platform, an intermediate connection box, and three ODNs (ODN 1, ODN 2, and ODN 3).

[0133] For the ODN, ODN1 connects to the left front surround view camera (based on 4Gbps transmission bandwidth) and the central control screen (based on 5.5Gbps transmission bandwidth) in the vehicle; ODN2 connects to the two front view cameras (based on 8.2Gbps transmission bandwidth) and the instrument panel screen (based on 1.9Gbps ​​transmission bandwidth) in the vehicle; ODN3 connects to the right rear surround view camera (based on 4Gbps transmission bandwidth), OTA / log (based on 500Mbps transmission bandwidth), and the passenger screen (based on 5.5Gbps transmission bandwidth) in the vehicle.

[0134] For the OLT / OAM platform:

[0135] 1) The intelligent driving OLT / OAM platform includes: intelligent driving diagnostic controller (based on 25Gbps transmission bandwidth), intelligent driving management plane (including: various OAM frames), and OLT optical modules (such as ADAS OLT-A1, ADAS OLT-A2, 1310nm OAM module, and WDM unit).

[0136] 2) The cockpit OLT / OAM platform includes: cockpit diagnostic controller (based on 25Gbps transmission bandwidth), cockpit management plane (including various OAM frames), and OLT optical modules (such as Cockpit OLT-C1, Cockpit OLT-C2, 1310nm OAM module, and WDM unit).

[0137] It should be understood that the vehicle is equipped with at least three ODNs, one or two intermediate fiber optic splice boxes, and dual computing platforms OLT. The control and management plane transmits between the OLT and ODN via a 1310 nm management wavelength, while the service plane continues to carry intelligent driving and cockpit services via 1490 / 1550 nm service wavelengths.

[0138] In one possible implementation, the diagnostic upper-level interface connects the vehicle diagnostic ECU, authorized aftermarket tools, and cloud interface.

[0139] The management plane OAM is responsible for encapsulating and parsing four types of OAM frames: LinkTrace, LoopBack, BER-Probe, and LatencyProbe. The OLT scheduler maintains the time slot table, statistics library, and permission hierarchy policy. The physical layer wavelength division multiplexing unit isolates the 1310nm management wavelength from the 1490 / 1550nm service wavelength through WDM filters. The input is management commands or probe requests, and the output is segment-level link status, BER, latency, and fault location results.

[0140] The OLT periodically sends LinkTrace frames on the management wavelength to record responses from each ODN and junction box. Upon detecting BER or latency anomalies, it sends BER-Probe or LatencyProbe frames. If the anomaly persists, it further initiates segment-by-segment LoopBack, combining calibration attenuation and feedback results to locate the faulty segment. All probe frames can be sent in the time slots reserved in the physical time slot table to ensure zero-awareness of the service plane.

[0141] The above is only a simple description of one possible implementation of the embodiments of this application. The following description takes any OLT / OAM platform, that is, any optical line terminal, as the execution subject.

[0142] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0143] Figure 2 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 1 ,like Figure 2 As shown, the method includes:

[0144] Step 21: Send the first probe frame to the link to be tested in the vehicle optical communication at a preset management wavelength;

[0145] The first detection frame is an error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be detected includes: at least two first nodes, and the first nodes include: a junction box or an optical distribution node.

[0146] In this step, the optical line terminal (OLT) is deployed as the central control node within the vehicle's optical communication network. The management wavelength, used to carry management information during detection, diagnosis, and positioning, is separated from the service wavelength carrying service data, thus distinguishing the diagnostic process from service transmission. The link to be tested is the target optical link in the vehicle's optical communication network, with one end connected to the OLT and the other end or an intermediate path connected to multiple first nodes, specifically junction boxes or optical distribution nodes.

[0147] Optionally, after the optical line terminal determines the link to be tested, it triggers the transmission of the first probe frame; the first probe frame is a management frame used for link health determination, and its frame header includes at least a link identifier field, a frame type field, a timestamp field, a destination field, and a check field, and the frame payload includes test parameters.

[0148] The error detection frame payload can contain a predetermined bit sequence, sequence length, and error statistics parameters, while the delay detection frame payload can contain the transmission time, sequence number, and delay measurement identifier. The optical line terminal (OLT) sends error detection frames when only error status is needed, delay detection frames when only delay status is needed, and both error detection frames and delay detection frames when both transmission quality and transmission timeliness need to be assessed simultaneously.

[0149] In one possible embodiment, the first probe frame is used to enable relevant nodes in the link under test to identify and return a response according to predetermined rules. For the bit error detection frame, after receiving a predetermined bit sequence, the first node can count the bit error rate between the received sequence and the standard sequence and form bit error response information; for the delay detection frame, after identifying the frame type, the first node can read the time information within the frame and perform a feedback, so that the optical line terminal can perform subsequent delay analysis.

[0150] Based on the above processing method, management information and business information are independent of each other at the wavelength level. The optical line terminal can continuously initiate detection when the service load changes, providing link status input for subsequent fault diagnosis.

[0151] It should be understood that the above examples are for illustrative purposes only and are not intended to be limiting.

[0152] Optionally, the first probe frame is an error detection frame; then one possible implementation of step 21 is to send the first probe frame to at least two first nodes in the link to be detected.

[0153] In this implementation, the link to be detected may include the junction box, optical distribution node and the optical fiber connection segment between them in the vehicle-mounted optical communication network.

[0154] After obtaining the topology information of the link to be tested, the optical line terminal sends the first probe frame to at least two first nodes according to the node distribution in the link to be tested, so that multiple first nodes can generate independent feedback for the same probe task. In practical applications, the message carrying format, sending order and number of nodes can also be configured according to the link length and network scale, which is not limited in this application.

[0155] Optionally, the first probe frame is a delayed probe frame; then one possible implementation of step 21 is to send delayed probe frames to at least two first nodes in the link to be detected.

[0156] In this implementation, there are at least two first nodes distributed sequentially along the physical topology of the link. The optical line terminal sends delay detection frames to each first node through the management wavelength, so that different nodes can independently complete the delay response at their respective link locations.

[0157] It should be understood that when sending the first probe frame, the optical line terminal can be configured with a management transceiver module, a frame encapsulation module, and a delay resolution module. The management transceiver module is responsible for sending the first probe frame on a preset management wavelength. The frame encapsulation module is used to generate a frame structure containing node identifiers and timestamp information. The delay resolution module is used to receive the response messages returned by each first node and extract the propagation delay, forwarding delay, or cumulative delay parameters.

[0158] Optionally, the management wavelength includes at least one of 1310 nm, 1270 nm, and 1330 nm; the service wavelength includes at least one of 1490 nm and 1550 nm.

[0159] In this implementation, the selection of the management wavelength can be determined in combination with the wavelength division characteristics of the link device. The relevant optical transmission module can use a laser component that supports 1270 nm, 1310 nm or 1330 nm emission, and the service transmission module can use a device that supports 1490 nm or 1550 nm emission. The two are coupled to the same optical fiber link via a wavelength division multiplexer.

[0160] In addition, the timing of sending operation and maintenance management frames based on the management wavelength is located in a preset time slot interval. The time slot interval is an idle time slot occupied by non-service data transmission. The operation and maintenance management frames include at least one of the following: error detection frames, delay detection frames, link tracing frames, and loopback frames.

[0161] In this implementation, the time slot gap can be identified by the optical line terminal according to the preset time slot table. The time slot table records the continuous transmission window occupied by the service data transmission and the adjacent idle segments. The frame transmission time within the idle segment is the time point.

[0162] Operation and maintenance management frames can be generated by the optical line terminal and encapsulated into a control frame format adapted to the vehicle-mounted optical link. The frame payload can carry error detection fields, delay measurement fields, link tracing identification fields or loopback control fields to correspond to error detection, delay detection, link tracing and fault segment location functions, respectively.

[0163] Correspondingly, the optical line terminal can align the transmission timing on the management wavelength through the clock synchronization module, and when it detects that the service burst corresponding to the service wavelength is not occupying link resources, it inserts the operation and maintenance management frame into the preset idle window and sends it.

[0164] The length of the time slot interval can be configured according to the service load cycle of the vehicle link, the length of the management frame, and the demultiplexing processing delay at the receiving end, so that the operation and maintenance management frame only occupies the non-service data transmission period. Both wavelength configuration and time slot configuration can be performed by the optical line terminal through the stored link parameter table. In practical applications, other models of this component can also be selected, and this application does not limit this.

[0165] Step 22: Determine whether the link under test is faulty based on the first response information received from the link under test;

[0166] In this step, the first response information is the feedback information returned by the node corresponding to the link to be detected in response to the first probe frame. Its content is used to characterize the actual state of the link in terms of bit error and / or delay.

[0167] For a bit error detection frame, the first response information may include the node identifier, the detection frame sequence number, the total number of received bits, the number of bit errors, and the bit error rate; for a delay detection frame, the first response information may include the node identifier, the detection frame sequence number, the reception time, the return time, and the round-trip delay value calculated by the optical line terminal.

[0168] Optionally, after sending the first probe frame, the optical line terminal opens the receiving window and receives the first response information in the receiving channel corresponding to the management wavelength. The optical signal output by the receiving channel is sent to the frame parsing module after photoelectric conversion. The frame parsing module classifies and caches the first response information according to the frame type field and the link identifier field. Then, the fault judgment module outputs the judgment result of whether the link to be detected has a fault according to the preset judgment rules.

[0169] In one possible implementation, the optical line terminal can verify the integrity and validity of the first response information, including frame header verification, sequence number matching, and source information matching. Based on the error state and / or delay state represented by the first response information, it can determine whether there is a fault in the link under test.

[0170] For example, whether the bit error rate is abnormal and / or the latency is abnormal can be used to determine whether the link under test is faulty. In some implementations, the link status can also be further determined by whether a first response message has been received.

[0171] Optionally, the first response information includes: error response information returned based on the error detection frame;

[0172] Accordingly, one possible implementation of step 22 could be:

[0173] Step 1: Obtain the error response information returned by each first node for the error detection frame;

[0174] In this implementation, error response information returned by each first node in response to the error detection frame is received.

[0175] Step 2: For each first node, if the bit error rate indicated in the bit error response information corresponding to the first node is greater than or equal to the bit error rate threshold corresponding to the first node, then it is determined that there is a fault in the link to be detected.

[0176] In this implementation, after obtaining the bit error rate response information returned by each first node, the optical line terminal compares the bit error rate in each bit error rate response information one by one.

[0177] When the bit error rate of a certain first node reaches or exceeds its corresponding bit error rate threshold, it indicates that the transmission quality of the link segment associated with that node has exceeded the allowable range, and the optical line terminal determines that there is a fault in the link to be tested.

[0178] It should be understood that the bit error rate threshold can be pre-configured by the optical line terminal based on the link type, node location or historical operation data and stored in the local parameter table. In practical applications, the threshold can also be configured in other ways, and this application does not limit this.

[0179] Step 3: For all first nodes, if the bit error rate indicated in the error response information of all first nodes is less than the bit error rate threshold corresponding to the first node, then it is determined that there is no fault in the link to be tested.

[0180] In this implementation, when the bit error rate of all first nodes is lower than their respective bit error rate thresholds, it is determined that there is no fault in the link to be detected.

[0181] It should be understood that the first response information can stably characterize the bit error detection results of each first node, and the optical line terminal can quickly determine the fault of the link under test based on this information. At the same time, based on the comparison relationship between the bit error rate per node and the bit error rate threshold, the dependence on the abnormal results of a single node can be reduced, making the judgment of whether the link under test is faulty more targeted and consistent, and providing an accurate basis for fault confirmation for the online monitoring and maintenance of the vehicle-mounted optical communication link.

[0182] In addition, the above-mentioned judgment results can be used as the triggering basis for locating faulty fiber segments in subsequent loopback frames, and output to the management and control module for recording and alarm.

[0183] Optionally, the first response information includes: delayed response information returned based on the delayed probe frame;

[0184] Accordingly, one possible implementation of step 22 could be:

[0185] Step 1: Obtain the delay response information returned by each first node in response to the delay probe frame;

[0186] In this implementation, after obtaining the delay response information returned by each first node, the optical line terminal completes a one-to-one mapping according to the node identifier and independently judges the delay value of each node (the implementation principle of the bit error rate is similar).

[0187] Step 2: For each first node, if the delay value indicated in the delay response information corresponding to the first node is greater than or equal to the delay threshold corresponding to the first node, then it is determined that there is a fault in the link to be detected.

[0188] In this implementation, when the delay value corresponding to any first node reaches or exceeds the delay threshold corresponding to that node, the optical line terminal outputs a judgment result indicating that the link under test has a fault. This result can be used as the trigger condition for subsequent loopback frame location processing.

[0189] It should be understood that the latency threshold can be preset based on the physical distance of the first node in the link, device insertion loss, historical calibration data and service tolerance latency, and stored in the threshold table of the optical line terminal. In practical applications, the threshold table can also adopt other storage organization methods, which are not limited in this application.

[0190] Step 3: For all first nodes, if the delay value indicated in the delay response information of all first nodes is less than the delay threshold corresponding to the first node, then it is determined that there is no fault in the link to be tested.

[0191] In this implementation, when the latency values ​​of all first nodes are lower than their respective latency thresholds, the optical line terminal outputs a judgment result that there is no fault in the link to be tested, and terminates further fault segment investigation.

[0192] It should be understood that this method uses multiple first nodes as link delay sampling points. By collecting the delay response information of each node separately and comparing it with a threshold, it achieves distributed judgment of abnormal link delay. Since the judgment conditions consider both single node exceeding limits and all nodes not exceeding limits, the optical line terminal can quickly obtain the link health status under the management wavelength and associate delay anomalies with specific nodes, thus providing clear input for subsequent faulty fiber segment location.

[0193] Step 23: If the link under test is faulty, determine the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test.

[0194] In this step, when step 22 outputs that there is a fault in the link to be detected, the optical line terminal initiates the segment-level positioning process.

[0195] The loopback frame is a positioning test frame transmitted on the management wavelength. Its function is to trigger the first node of the target in the link under test to return the received positioning signal so as to determine the fiber segment where the anomaly occurred, i.e., the faulty fiber segment, based on the second response information. The second response information is the feedback information formed in response to the loopback frame, which can characterize the return status of the loopback frame and is used to determine the faulty fiber segment. The faulty fiber segment is the abnormal segment that is finally identified in the link under test. Its boundary is determined by the fiber connection segment between two adjacent nodes or between the optical line terminal and the first node (of course, in some implementations, it may also include the corresponding node).

[0196] In one possible implementation, the optical line terminal (OLT) sends a loopback frame to the link under test. The loopback frame includes at least the link identifier, target node information, loopback command, transmission time information, and test parameters. Upon receiving the loopback frame at the management wavelength, the corresponding first node performs a return operation within its local management channel and sends the result back to the OLT as a second response. After receiving and parsing the second response, the OLT determines the faulty fiber segment in the link under test.

[0197] Furthermore, the method may also include the following implementations:

[0198] Step 1: If the link to be tested is faulty, obtain the target diagnostic information involved in the fault location of the link to be tested;

[0199] In this implementation, the target diagnostic information is a set of diagnostic information generated and collected during the fault location process of the link under test. It can be composed of the feedback information obtained by the optical line terminal after sending bit error detection frames, delay detection frames or loopback frames, and can include: fault segment identifier, bit error rate, delay value, node hop count, attenuation value and link topology association information, etc.

[0200] Correspondingly, after confirming that there is a fault in the link to be tested, the optical line terminal will aggregate the fault location results, link status records, and response message content generated during the location process into target diagnostic information and store it in the local diagnostic cache or vehicle diagnostic database.

[0201] Step 2: Identify the diagnostic data corresponding to different diagnostic access permissions in the target diagnostic information.

[0202] In this implementation, diagnostic access permissions are used to set different data visibility ranges for different access subjects. The access subjects may include vehicle controllers, network management units, after-sales diagnostic equipment, or remote operation and maintenance terminals. Diagnostic access permissions can be divided according to fault location level, maintenance level, or security level. Diagnostic data is a subset of data that matches the corresponding permissions and is separated from the target diagnostic information. It can output only the link segments, performance parameters, or fault conclusions corresponding to the current access subject according to the permission rules.

[0203] Accordingly, the optical line terminal performs hierarchical processing of target diagnostic information based on a pre-configured permission mapping table. The permission mapping table records the readable fields, readable ranges, and desensitization rules corresponding to different access roles. Based on this, the terminal divides the complete diagnostic information into multiple data sets and generates diagnostic data for different diagnostic access permissions.

[0204] For higher access permissions (e.g., vehicle diagnostic ECU), complete diagnostic data including faulty fiber segment identifier, node coordinates, and link performance parameters can be output; for medium access permissions (e.g., authorized after-sales tools), faulty ODN / segment identifier and suggested repair operations can be output, but complete frame-by-frame diagnostic data is not included; for lower access permissions (e.g., cloud / remote interface), only limited diagnostic data such as whether the link is abnormal, whether it needs to be repaired, and the corresponding alarm code are output.

[0205] It should be understood that the permission level is preset by the OLT during the factory stage through diagnostic configuration version, and except for special requirements, it is generally not possible to dynamically exceed the permission level during operation.

[0206] The fiber optic fault location method provided in this application is applied to an optical line terminal. The method involves sending a first detection frame (which may be an error detection frame or a delay detection frame) to a link under test in a vehicle-mounted optical communication system at a preset management wavelength. The management wavelength differs from the service wavelength used for data transmission. The link under test includes at least two first nodes, each including a junction box or an optical distribution node. Based on the first response information received from the link under test, the method determines whether a fault exists in the link under test. If a fault exists, the method identifies the faulty fiber segment in the link under test based on the second response information corresponding to a loopback frame sent to the link under test. This technical solution fundamentally avoids mutual interference between fault detection signals and service data transmission by sending probe frames using a management wavelength independent of the service wavelength, thus achieving real-time perception of link status without affecting normal communication. Simultaneously, by first screening the entire link using error detection frames or delay detection frames, the existence of faults can be quickly determined, avoiding the inefficiency of segment-by-segment troubleshooting. Once a fault is confirmed, the fault location granularity is refined from the link level to the specific fiber segment through the response information of the loopback frame. This solves the technical challenge of existing methods, which cannot distinguish between service signals and detection signals and lack a segmented location mechanism, making it difficult to accurately locate faulty fiber segments without interrupting services.

[0207] Based on the above embodiments, Figure 3 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 2 ,like Figure 3 As shown, one possible implementation of determining the faulty fiber segment in the link under test in step 23 based on the second response information corresponding to the loopback frame sent to the link under test may include:

[0208] Step 31: Starting from the optical line terminal, based on the physical topology of the link to be tested, send loopback frames to the first node in sequence from near to far.

[0209] In this step, the optical line terminal is used to sequentially probe each first node on the link to be tested and receive the corresponding second response information; multiple first nodes in the link to be tested are connected in series to form an in-vehicle optical fiber connection link; the physical topology order is used to characterize the sequential position of each first node in the actual connection path; the first node is configured with a loopback forwarding unit for sending back loopback frames.

[0210] Optionally, the optical line terminal first reads the physical topology configuration of the link to be tested, generates a loopback frame sending instruction in the order of starting from the first node closest to the optical line terminal and gradually advancing to the first node at the far end, and sends the loopback frame to each first node in sequence.

[0211] Step 32: For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, then the fiber segment at the first node is determined to be a faulty fiber segment.

[0212] In this step, the first preset condition is used to characterize the abnormal state of a link segment corresponding to a certain first node. The abnormal state can be reflected by the second response information being empty, the real-time round-trip delay value exceeding the threshold, or the attenuation index exceeding the threshold.

[0213] Optionally, after receiving a loopback frame, each first node performs loopback processing on it and returns a second response message. The optical line terminal performs a matching judgment on the second response message. When the judgment result meets the first preset condition, the optical fiber segment between the first node and the optical line terminal can be identified as a faulty optical fiber segment.

[0214] To adapt to the link length and number of nodes of different vehicle models, the message format of the loopback frame, the field content of the second response information, and the threshold parameters of the first preset condition can all be pre-written by the vehicle network configuration file. In practical applications, this application does not impose any restrictions on this.

[0215] In one possible implementation, the first node may be equipped with a monitoring unit for transmitting real-time attenuation and real-time delay values. After receiving the looped-back management wavelength signal, the monitoring unit generates real-time attenuation and real-time delay values ​​based on the received power, transmitted power, and round-trip time, and encapsulates them as a second response message to return to the optical line terminal.

[0216] Optionally, the first preset condition includes at least one of the following:

[0217] 1) The second response information is empty;

[0218] In this implementation, when the second response information fails to return or is reported as empty, it indicates that the corresponding link segment may be interrupted, the port may be disconnected, or the return transmission may have failed.

[0219] 2) The second response information indicates that the real-time attenuation value is greater than or equal to the preset first value corresponding to the first node;

[0220] In this implementation, when the real-time attenuation value reaches or exceeds the first value corresponding to the first node, it indicates that the link loss at that node exceeds the allowable range.

[0221] 3) The second response information indicates that the real-time delay value is greater than or equal to the preset second value corresponding to the first node.

[0222] In this implementation, when the real-time latency value reaches or exceeds the second value, it indicates that the link transmission delay at that node is abnormal.

[0223] It should be understood that the first and second values ​​can be pre-configured based on the link length, fiber type, number of connectors and system delay budget of the first node and stored in the determination table of the optical line terminal. In practical applications, other models of this component can also be selected, and this application does not limit them.

[0224] The fiber optic fault location method provided in this application embodiment involves sending loopback frames sequentially to the first node from near to far, starting from the optical line terminal and based on the physical topology of the link to be tested. For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, the fiber segment at the first node is determined to be a faulty fiber segment. This technical solution uses a step-by-step loopback mechanism, starting from the optical line terminal and strictly following the physical topology order to send loopback frames from near to far. This ensures that the detection signal is transmitted in an orderly manner along the optical fiber link, avoiding response confusion and detection blind spots caused by disordered transmission. Simultaneously, since each loopback operation only targets a single first node, the fault diagnosis of the entire link can be decomposed into multiple independent single-segment tests, significantly reducing the complexity of parsing response information when multiple faults overlap. By comparing the second response information of each first node to see if it meets a first preset condition, the fault determination granularity can be precisely converged from the link level to the fiber segment level between adjacent nodes. Furthermore, if a node closer to the terminal meets the condition, the possibility of faults in all upstream nodes can be ruled out, thus achieving unidirectional progressive locking of the fault segment. Finally, without interrupting service communication, by independently transmitting detection frames using the management wavelength, combined with this step-by-step loopback positioning mechanism, abnormal fiber segments in the link can be accurately identified with minimal signaling overhead and the fastest convergence speed, significantly improving the efficiency and accuracy of fault location in vehicular optical communication scenarios.

[0225] Based on the above embodiments, Figure 4 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 3 ,like Figure 4 As shown, prior to step 21, the method further includes:

[0226] Step 41: For each communication link in the vehicle-mounted optical communication, obtain the first performance data of the communication link;

[0227] The first performance data includes: cumulative attenuation values ​​and / or missing response data;

[0228] In this step, the communication link can refer to the link object in the vehicle-mounted optical communication network, which consists of optical line terminals, junction boxes, optical distribution nodes and the optical fiber segments between them. The link object is used to undergo pre-screening before sending the first probe frame.

[0229] Accordingly, the first performance data is used to characterize the current health status of the communication link. It can be obtained from historical monitoring records, management message interaction records or online detection statistics on the link side, and serves as a preliminary basis for judging the link to be tested.

[0230] The cumulative attenuation value in the first performance data is used to characterize the cumulative loss of the communication link within a preset statistical period; the response missing data in the first performance data is used to characterize the number of times or duration during continuous probing when the communication link fails to return a response. The two can be used alone or in combination.

[0231] Step 42: Based on the first performance data, determine whether the communication link is the link to be tested.

[0232] In this step, based on the first performance data, it can be preliminarily determined whether there is an anomaly in the corresponding communication link. If there is an anomaly, the communication link is identified as the link to be tested.

[0233] Optionally, the first performance data includes: cumulative attenuation value; then one possible implementation of step 42 is: if the cumulative attenuation value is greater than or equal to a preset attenuation value threshold, then the communication link is determined as the link to be detected.

[0234] In this implementation, the cumulative attenuation value can be calculated by the optical line terminal based on the difference between the transmit power and the receive power at both ends of the link, or it can be formed by accumulating the attenuation values ​​recorded by each node in the link at multiple sampling times. The preset attenuation value threshold is a judgment standard pre-written into the storage unit, and its value can be configured according to different link lengths, fiber types and installation attenuation margins in the vehicle.

[0235] Furthermore, after the optical line terminal obtains the cumulative attenuation value of the communication link, it compares the cumulative attenuation value with the attenuation value threshold. When the cumulative attenuation value reaches or exceeds the threshold, the communication link is marked as a link to be detected.

[0236] The acquisition and comparison of cumulative attenuation values ​​can be completed by the processor and memory in the vehicle-mounted optical communication management module. The processor calls the corresponding threshold table entry for judgment. In practical applications, other models of processor and memory can also be selected, and this application does not limit them.

[0237] Optionally, the first performance data includes: response missing data; then one possible implementation of step 42 is: if the response missing data indicates that the number of consecutive missing data is greater than a preset missing data threshold, then the communication link is determined as the link to be detected.

[0238] In this implementation, the threshold for the number of missing occurrences is a pre-configured upper limit for judgment. Its value can be set according to the length of the vehicle-mounted optical communication link, the number of nodes, and the round-trip delay range of management messages, and is stored in the link management parameter table of the optical line terminal.

[0239] Furthermore, after the optical line terminal completes the response reception monitoring of each communication link, it compares the current number of consecutive missing links with the missing link threshold. When the number of consecutive missing links exceeds the missing link threshold, it is marked as a link to be tested.

[0240] In one possible implementation, the optical line terminal (OLT) can maintain a missing counter for each communication link through a management and control module. When a probe frame is sent and no response is received within a specified response window, the counter increments; when a valid response is received, the counter is reset to zero or rolled back according to a preset rule. The state of this counter constitutes the missing response data. When the number of consecutive missing responses reaches a preset threshold, the link is determined to be in an abnormal attention state and identified as a link to be tested.

[0241] The fiber optic fault location method provided in this application obtains first performance data for each communication link in the vehicle-mounted optical communication. The first performance data includes: cumulative attenuation value and / or response missing data. Based on the first performance data, it is determined whether the communication link is a link to be detected. This technical solution independently collects first-level performance data for each communication link in vehicular optical communication, enabling the quantification of the physical transmission quality and interaction health of each link from a global perspective. This avoids the limitations of relying on a single indicator or subjective experience for rough judgment. Based on this, the cumulative attenuation value can identify potentially hazardous links with continuously deteriorating optical power but not yet completely interrupted, while missing response data can capture abnormal behaviors such as sudden packet loss or unresponsive nodes. The two complement each other, covering two typical scenarios: slow degradation and sudden failure. By linking these two types of quantitative indicators with preset thresholds, the solution can objectively and automatically select the links with the most severe performance degradation as targets for detection. This concentrates limited detection resources on high-risk links, avoiding the bandwidth waste and processing overhead caused by periodically polling all links. Ultimately, without manual intervention or interruption of service communication, it achieves early warning and accurate location of potentially faulty links, providing a clear detection entry point for subsequent step-by-step loopback positioning, and significantly improving the intelligence level and response efficiency of vehicular optical communication network operation and maintenance.

[0242] Based on the above embodiments, Figure 5 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 4 ,like Figure 5 As shown, prior to step 41, the method further includes:

[0243] Step 51: Periodically broadcast link tracking frames to at least one passive optical network port of the optical line terminal at a managed wavelength.

[0244] In this step, the optical line terminal (OLT) acts as the sender of the link tracing frame, periodically broadcasting probe information to the downstream link through at least one passive optical network port, so that the junction box or optical distribution node sends back a third response message after receiving the link tracing frame.

[0245] Optionally, the passive optical network port can be configured as a management interface for connection to downstream optical fibers. The link tracing frame can use a predefined management message, which carries a link identification field and a tracing identifier to support multiple nodes in the network to respond to the same broadcast frame.

[0246] Step 52: Obtain the third response information returned based on the link tracing frame;

[0247] The third response information includes: the hop count of each node, and the nodes include: junction boxes or optical distribution nodes;

[0248] In this step, the hop count of each node recorded in the third response information indicates the hierarchical position of the corresponding node relative to the optical line terminal or the number of relays traversed. The optical line terminal can then determine the connection order between nodes based on this information.

[0249] Optionally, after receiving the link tracing frame, the junction box or optical distribution node can generate a response frame containing hop count information according to its preset processing logic and return it to the optical line terminal. The optical line terminal then determines the hop count in each response frame.

[0250] Optionally, the third response information may also include: the attenuation values ​​of each node;

[0251] Accordingly, the method also includes: constructing an attenuation threshold based on the attenuation values ​​of each node in the communication link.

[0252] In this implementation, a node can correspond to a junction box or an optical distribution node. The attenuation value is used to characterize the loss level of the link segment where the node is located. The value can be obtained by the optical line terminal in combination with the optical power information, bit error characterization information or pre-calibrated link loss parameters in the returned message.

[0253] Subsequently, after obtaining the attenuation values ​​of each node, the optical line terminal constructs an attenuation value threshold based on multiple attenuation samples within the same communication link.

[0254] The attenuation threshold can be determined by the maximum, average, statistical quantile, or weighted result of the attenuation values ​​of each node in the link, and can be superimposed with a preset margin to form a corresponding upper limit value, so that it can correspond to the normal loss boundary of different link segments. The attenuation threshold can be stored together with the link identifier in the link management unit of the terminal for subsequent comparison and judgment of the cumulative attenuation value.

[0255] It should be understood that in practical applications, the calculation method of this attenuation threshold can also be adjusted according to different vehicle models, different fiber lengths, or different node types, and this application does not limit it in this regard.

[0256] Step 53: Based on the hop count of each node, construct at least one communication link.

[0257] In this step, communication link objects are created in ascending order of hop count, associating nodes on the same physical path as a complete link. The construction results of the communication links can be written to the link management table for subsequent use in obtaining initial performance data and troubleshooting.

[0258] It should be understood that the periodic transmission interval of the link tracing frame can be set to a fixed duration according to management requirements to continuously update the topology information. In practical applications, the management wavelength, port type, and response frame format can also be implemented in other ways, and this application does not limit them.

[0259] The fiber optic fault location method provided in this application involves periodically broadcasting link tracing frames to at least one passive optical network port of the optical line terminal at a management wavelength; obtaining third response information returned based on the link tracing frames, the third response information including: the hop count of each node, the nodes including: a junction box or an optical distribution node; and constructing at least one communication link based on the hop count of each node. This technical solution periodically broadcasts link tracking frames with an independent management wavelength, completely isolating the probe signal from service data at the physical layer. This allows for proactive initiation of a network-wide topology discovery process without interfering with normal communication. Furthermore, by using a broadcast method instead of polling, a single tracking frame can trigger responses from all downstream nodes simultaneously, significantly reducing signaling interactions and overall detection time, thus greatly improving topology acquisition efficiency in large-scale networks. By analyzing the hop count information returned by each node, the hierarchical position of each junction box or optical distribution node relative to the optical line terminal can be accurately obtained, quantifying the originally black-box passive optical distribution network into an ordered sequence of nodes. Finally, based on this hop count data, a complete communication link topology can be automatically constructed, providing a precise network map foundation for subsequent link performance monitoring, fault segmentation and location, and path planning. This enables automated operation and maintenance capabilities for topology self-discovery and dynamic updates in vehicular optical communication networks.

[0260] Based on the above embodiments, Figure 6 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 5 ,like Figure 6 As shown, one possible implementation of this method could be:

[0261] Step 61: Periodic LinkTrace frames; Error detection;

[0262] Step 62, BER-Probe frame; on demand;

[0263] Step 63, LatencyProbe frame; anomaly detection;

[0264] Step 64: BER / Latency anomaly? If yes, proceed to step 65; otherwise, end; stage location.

[0265] Step 65: Initiate LoopBack positioning segment by segment; write statistics;

[0266] Step 66: Write to the statistics database (business-unnoticed);

[0267] Step 67: Expose the results to external parties according to permissions; permission exposure.

[0268] Based on the above embodiments, Figure 7 A flowchart illustrating the fiber optic fault location method provided in this application embodiment. Figure 6 ,like Figure 7 As shown, one possible implementation of the LoopBack segment-level positioning timing sequence could be:

[0269] The main entities responsible for implementation include: OLT, intermediate junction box, ODN 3, and vehicle diagnostics.

[0270] The implementation steps are as follows:

[0271] Step 71: The OLT sends the BER-Probe (1310nm) to ODN 3;

[0272] Step 72: ODN 3 returns a BER 5e-7 exception to OLT;

[0273] Step 73: The OLT sends LoopBack-1 (middle section) to the intermediate connection box;

[0274] Step 74: The intermediate junction box sends a normal feedback to the OLT;

[0275] Step 75: The OLT sends LoopBack-2 (right rear half) to the middle ODN 3.

[0276] Step 76: ODN 3 returns a BER exception to OLT - locating the right rear half;

[0277] Step 77: OLT reports stage faults to the vehicle diagnostics system.

[0278] Based on the above Figure 1 , Figure 6 and Figure 7 The following is an example of an after-sales maintenance scenario for a vehicle-mounted optical communication system during its usage phase:

[0279] When a vehicle is subjected to vibration, temperature changes, or localized physical damage during operation, an optical line terminal (OLT) deployed inside the vehicle periodically broadcasts link tracking frames to at least one passive optical network (PON) port using a management wavelength selected from at least one of 1310 nm, 1270 nm, and 1330 nm, distinct from the 1490 nm and 1550 nm service wavelengths. All operation and maintenance management frames are transmitted within preset time slots. These time slots are idle time slots, not those occupied by service data transmission. For example, when the vehicle is parked and service load is low, the time slot percentage can be set to 5%, while during daytime operation and service load is high, the time slot percentage can be set to 1%.

[0280] In one possible implementation, the optical line terminal (OLT) sends link tracing frames to each junction box and optical distribution node via a 1310 nm management wavelength and receives third response information returned based on the link tracing frames. The third response information includes the hop count of each node (either a junction box or an optical distribution node), and may also include the attenuation value, node identifier, received optical power, and cumulative path attenuation of each node. The OLT constructs at least one communication link based on the hop count of each node, establishes a corresponding attenuation threshold based on the attenuation value of each node in the communication link, and obtains first performance data for each communication link. The first performance data includes the cumulative attenuation value and / or missing response data.

[0281] For example, in a smart car, the third response information returned by the right rear optical distribution node ODN 3 contains the corresponding hop count and cumulative attenuation. If the cumulative attenuation value of the communication link is greater than or equal to a preset attenuation value threshold, the communication link is identified as a link to be tested. If the number of consecutive missing data in the response indicates that the number of missing data is greater than a preset number of missing data threshold, the communication link is also identified as a link to be tested.

[0282] Once the communication link where the right rear ODN 3 is located is identified as the link to be tested, the optical line terminal sends a first probe frame to the link to be tested in the vehicle-mounted optical communication at a management wavelength. The first probe frame is an error detection frame and / or a delay detection frame. The link to be tested includes at least two first nodes, which are junction boxes or optical distribution nodes, for example, including the middle junction box and the right rear optical distribution node ODN 3.

[0283] When the first detection frame uses a bit error rate (BER) detection frame, the optical line terminal (OLT) sends BER detection frames to at least two first nodes and obtains the BER response information returned by each first node. For example, ODN 3 can send back a predetermined bit sequence for BER measurement. If the bit error rate indicated in the BER response information of any first node is greater than or equal to the BER threshold corresponding to that first node, the link under test is determined to be faulty. If the bit error rate indicated in the BER response information of all first nodes is less than their respective BER thresholds, the link under test is determined to be fault-free. In this vehicle-mounted example, the BER of ODN 3 can be detected as 5e-7, and this is compared with the corresponding BER threshold.

[0284] When the first detection frame uses a delay detection frame, the optical line terminal sends delay detection frames to at least two first nodes in the link under test and obtains the delay response information returned by each first node. If the delay value indicated in the delay response information corresponding to any first node is greater than or equal to the delay threshold corresponding to that first node, the link under test is determined to be faulty; if the delay values ​​indicated in the delay response information corresponding to all first nodes are less than their respective delay thresholds, the link under test is determined to be fault-free. Corresponding to after-sales maintenance scenarios, the delay response information can form a data foundation for vehicle diagnostics, such as the delay values ​​recorded by node and the resulting delay statistics.

[0285] When a link under test is determined to be faulty, the optical line terminal (OLT) sends loopback frames to each first node sequentially, from near to far, according to the physical topology of the link under test, starting from itself. It then receives the second response information returned by each first node in response to the loopback frames. For example, for a link containing a central junction box and a right rear ODN3, the OLT first sends a loopback frame to the central junction box. The central junction box returns a second response information indicating a real-time attenuation value of 4.1 dB. If this value is lower than or does not reach the allowable judgment boundary near the preset first value of 4.0 dB corresponding to the first node, and the real-time delay value in the second response information does not reach the preset second value corresponding to the first node, the corresponding fiber segment is not identified as a faulty fiber segment. Subsequently, the optical line terminal (OLT) sends a loopback frame to ODN 3. The second response information returned by ODN 3 indicates a real-time attenuation value of 11.8 dB, corresponding to a calibrated attenuation of 10.0 dB, and may be accompanied by bit error anomalies in the returned sequence. If the second response information is empty, or the real-time attenuation value indicated therein is greater than or equal to a preset first value corresponding to the first node, or the real-time delay value indicated therein is greater than or equal to a preset second value corresponding to the first node, then the fiber segment at the first node is identified as a faulty fiber segment. In the above example, the right rear fiber segment between the splice box and ODN 3 can be identified as a faulty fiber segment.

[0286] In the event of a fault in the link under test, the optical line terminal also acquires the target diagnostic information involved in the fault location of the link under test, and distinguishes the diagnostic data corresponding to different diagnostic access permissions in the target diagnostic information.

[0287] For example, the vehicle diagnostic ECU can obtain frame-by-frame bit error rate, delay histogram, fault segment identifier, and original diagnostic event records; authorized after-sales tools can obtain a fault summary of the right rear fiber optic segment anomaly and a repair prompt to replace the fiber optic segment; the cloud interface can obtain the processing results of events with bit error rate anomaly and the right rear fiber optic segment being located, but does not include complete vehicle topology information.

[0288] The fiber optic fault location method provided in this application introduces a three-layer approach: a management wavelength isolated from the physical layer of the service plane, service-insensitive gap diagnosis, and segment-level LoopBack location. This enables the management plane response of vehicle optical communication to be unaffected by service bursts, online diagnosis to be zero-sensory for services, and fault location accuracy to the fiber segment level, thus significantly improving the efficiency of vehicle after-sales maintenance.

[0289] Based on the above embodiments, Figure 8 This is a schematic diagram of the structure of the optical fiber fault location system provided in the embodiments of this application, as shown below. Figure 8 As shown, the system includes: an optical line terminal and at least one node directly or indirectly connected to the terminal, the node including: a junction box or an optical distribution node;

[0290] This optical line terminal is used to perform the aforementioned optical fiber fault location method.

[0291] This application also provides a vehicle, which includes: an optical line terminal performing the aforementioned optical fiber fault location method; or, the aforementioned optical fiber fault location system.

[0292] Figure 9 This is a schematic diagram of the structure of the optical fiber fault location device provided in the embodiments of this application, as shown below. Figure 9 As shown, the optical fiber fault location device is applied to the optical line terminal in a vehicle, and includes:

[0293] The transmitting module 91 is used to transmit a first probe frame to the link to be tested in the vehicle-mounted optical communication at a preset management wavelength. The first probe frame is an error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be tested includes at least two first nodes, and the first nodes include a junction box or an optical distribution node.

[0294] The first determining module 92 is used to determine whether there is a fault in the link to be tested based on the first response information received corresponding to the link to be tested;

[0295] The second determining module 93 is used to determine the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test when there is a fault in the link under test.

[0296] In one or more embodiments, the second determining module 93 determines the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test, specifically for:

[0297] Starting from the optical line terminal, loopback frames are sent sequentially to the first node from near to far, based on the physical topology of the link to be tested.

[0298] For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, then the fiber segment at the first node is determined to be a faulty fiber segment.

[0299] In one or more embodiments, the first preset condition includes at least one of the following:

[0300] The second response message is empty;

[0301] The second response information indicates that the real-time attenuation value is greater than or equal to the preset first value corresponding to the first node;

[0302] The second response information indicates that the real-time delay value is greater than or equal to the preset second value corresponding to the first node.

[0303] In one or more embodiments, the first detection frame is a bit error detection frame;

[0304] Correspondingly, the transmitting module 91 sends a first probe frame to the link to be tested in the vehicle-mounted optical communication, specifically for:

[0305] Send a first probe frame to at least two first nodes in the link to be detected.

[0306] In one or more embodiments, the first response information includes: error response information returned based on the error detection frame;

[0307] Accordingly, the first determining module 92 determines whether the link under test is faulty based on the first response information received from the link under test, specifically for:

[0308] Obtain the error response information returned by each first node for the error detection frame;

[0309] For each first node, if the bit error rate indicated in the bit error response information corresponding to the first node is greater than or equal to the bit error rate threshold corresponding to the first node, then it is determined that there is a fault in the link to be detected.

[0310] For all first nodes, if the bit error rate indicated in the error response information of all first nodes is less than the bit error rate threshold corresponding to the first node, then it is determined that there is no fault in the link to be tested.

[0311] In one or more embodiments, the first probe frame is a delayed probe frame;

[0312] Correspondingly, the transmitting module 91 sends a first probe frame to the link to be tested in the vehicle-mounted optical communication, specifically for:

[0313] Send delayed probe frames to at least two first nodes in the link to be detected.

[0314] In one or more embodiments, the first response information includes: delayed response information returned based on the delayed probe frame;

[0315] Accordingly, the first determining module 92 determines whether the link under test is faulty based on the first response information received from the link under test, specifically for:

[0316] Obtain the delay response information returned by each first node in response to the delay probe frame;

[0317] For each first node, if the delay value indicated in the delay response information corresponding to the first node is greater than or equal to the delay threshold corresponding to the first node, then it is determined that there is a fault in the link to be detected.

[0318] For all first nodes, if the delay value indicated in the delay response information of all first nodes is less than the delay threshold corresponding to the first node, then it is determined that there is no fault in the link to be tested.

[0319] In one or more embodiments, before sending the first probe frame to the link to be detected in the vehicular optical communication at a preset management wavelength, the first determining module 92 is further configured to:

[0320] For each communication link in the vehicle-mounted optical communication, the first performance data of the communication link is obtained. The first performance data includes: cumulative attenuation value and / or missing response data.

[0321] Based on the initial performance data, determine whether the communication link is the link to be tested.

[0322] In one or more embodiments, the first performance data includes: a cumulative attenuation value;

[0323] Accordingly, the first determining module 92, based on the first performance data, determines whether the communication link is the link to be detected, specifically for:

[0324] If the cumulative attenuation value is greater than or equal to the preset attenuation value threshold, the communication link will be identified as the link to be detected.

[0325] In one or more embodiments, the first performance data includes: response missing data;

[0326] If the number of consecutive missing data indications in the response exceeds a preset missing data threshold, the communication link is identified as a link to be detected.

[0327] In one or more embodiments, before acquiring the first performance data of the communication link, the first determining module 92 is further configured to:

[0328] To manage wavelengths, link tracking frames are periodically broadcast to at least one passive optical network port of the optical line terminal;

[0329] Obtain the third response information returned based on the link tracing frame. The third response information includes: the hop count of each node, and the nodes include: the junction box or the optical distribution node.

[0330] Based on the hop count of each node, at least one communication link is constructed.

[0331] In one or more embodiments, the third response information further includes: the attenuation value of each node;

[0332] Correspondingly, the first determining module 92 is also used for:

[0333] Based on the attenuation values ​​of each node in the communication link, an attenuation threshold is constructed.

[0334] In one or more embodiments, the first determining module 92 is further configured to:

[0335] If the link under test is faulty, obtain the target diagnostic information involved in the fault location of the link under test;

[0336] The diagnostic data corresponding to different diagnostic access permissions is identified in the target diagnostic information.

[0337] In one or more embodiments, the management wavelength includes at least one of 1310 nm, 1270 nm, and 1330 nm; the service wavelength includes at least one of 1490 nm and 1550 nm.

[0338] The timing of sending operation and maintenance management frames based on the management wavelength is located in a preset time slot interval. The time slot interval is an idle time slot occupied by non-service data transmission. The operation and maintenance management frame includes at least one of the following: error detection frame, delay detection frame, link tracing frame, and loopback frame.

[0339] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical element, or they can be physically separated. Furthermore, these modules can be implemented entirely in software through processing element calls, or entirely in hardware. Alternatively, some modules can be implemented through processing element calls in software, while others can be implemented in hardware. Moreover, these modules can be integrated together or implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed through the integrated logic circuits in the hardware of the processor element or through software instructions.

[0340] As can be seen from the above, the optical fiber fault location device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0341] Figure 10 This is a schematic diagram of the structure of an optical line terminal provided in an embodiment of this application. Figure 10 As shown, the optical line terminal provided in this embodiment includes at least one processor 101 and a memory 102.

[0342] Optionally, the optical line terminal also includes a communication component 103.

[0343] The processor 101, memory 102 and communication component 103 are connected via bus 104.

[0344] In a specific implementation, at least one processor 101 executes computer execution instructions stored in memory 102, causing at least one processor 101 to perform the above-described method.

[0345] The specific implementation process of processor 101 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0346] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0347] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0348] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0349] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0350] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0351] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0352] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0353] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0354] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0355] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0356] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0357] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0358] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for locating faults in optical fibers, characterized in that, The method for use in optical line terminals in vehicles includes: A first detection frame is sent to the link to be tested in the vehicle-mounted optical communication at a preset management wavelength. The first detection frame is a bit error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be tested includes at least two first nodes, and the first nodes include a junction box or an optical distribution node. Based on the first response information received corresponding to the link to be tested, it is determined whether the link to be tested is faulty; If the link under test is faulty, the faulty fiber segment in the link under test is determined according to the second response information corresponding to the loopback frame sent to the link under test.

2. The method according to claim 1, characterized in that, The step of determining the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test includes: Starting from the optical line terminal, and based on the physical topology of the link to be detected, the loopback frames are sent sequentially to the first node from near to far. For each first node, if the second response information corresponding to the loopback frame of the first node meets the first preset condition, then the fiber segment at the first node is determined to be the faulty fiber segment.

3. The method according to claim 2, characterized in that, The first preset condition includes at least one of the following: The second response information indicates that it is empty; The second response information indicates that the real-time attenuation value is greater than or equal to the preset first value corresponding to the first node; The second response information indicates that the real-time delay value is greater than or equal to the preset second value corresponding to the first node.

4. The method according to any one of claims 1-3, characterized in that, The first detection frame is the bit error detection frame; Accordingly, sending the first probe frame to the link to be tested in the vehicle-mounted optical communication includes: The first probe frame is sent to at least two first nodes in the link to be detected.

5. The method according to claim 4, characterized in that, The first response information includes: error response information returned based on the error detection frame; Accordingly, determining whether the link under test is faulty based on the first response information received from the link under test includes: Obtain the error response information returned by each first node for the error detection frame; For each first node, if the bit error rate indicated in the error response information corresponding to the first node is greater than or equal to the bit error rate threshold corresponding to the first node, then it is determined that the link to be detected has a fault. For all first nodes, if the bit error rate indicated in the error response information corresponding to all first nodes is less than the bit error rate threshold corresponding to the corresponding first node, then it is determined that the link to be tested has no fault.

6. The method according to any one of claims 1-3, characterized in that, The first detection frame is the delayed detection frame; Accordingly, sending the first probe frame to the link to be tested in the vehicle-mounted optical communication includes: The delay detection frame is sent to at least two first nodes in the link to be detected.

7. The method according to claim 6, characterized in that, The first response information includes: delayed response information returned based on the delayed detection frame; Accordingly, determining whether the link under test is faulty based on the first response information received from the link under test includes: Obtain the delay response information returned by each first node in response to the delay probe frame; For each first node, if the delay value indicated in the delay response information corresponding to the first node is greater than or equal to the delay threshold corresponding to the first node, then it is determined that the link to be detected is faulty. For all first nodes, if the delay value indicated in the delay response information corresponding to all first nodes is less than the delay threshold corresponding to the corresponding first node, then it is determined that the link to be tested is not faulty.

8. The method according to any one of claims 1-3, characterized in that, Before sending the first probe frame to the link under test in the vehicular optical communication at a preset management wavelength, the method further includes: For each communication link in the vehicle-mounted optical communication, first performance data of the communication link is obtained, the first performance data including: cumulative attenuation value and / or response missing data; Based on the first performance data, determine whether the communication link is the link to be detected.

9. The method according to claim 8, characterized in that, The first performance data includes: cumulative attenuation value; Accordingly, determining whether the communication link is the link to be detected based on the first performance data includes: If the cumulative attenuation value is greater than or equal to a preset attenuation value threshold, then the communication link is identified as the link to be detected.

10. The method according to claim 8, characterized in that, The first performance data includes: missing response data; If the number of consecutive missing response data indicates that the number of missing data is greater than a preset threshold, then the communication link is identified as the link to be detected.

11. The method according to claim 9, characterized in that, Before acquiring the first performance data of the communication link, the method further includes: Link tracking frames are periodically broadcast to at least one passive optical network port of the optical line terminal at the management wavelength. Obtain the third response information returned based on the link tracing frame. The third response information includes: the hop count of each node, and the nodes include: a junction box or an optical distribution node. Based on the hop count of each node, at least one communication link is constructed.

12. The method according to claim 11, characterized in that, The third response information also includes: the attenuation values ​​of each node; Accordingly, the method further includes: The attenuation threshold is constructed based on the attenuation values ​​of each node in the communication link.

13. The method according to any one of claims 1-3, characterized in that, The method further includes: If the link to be tested is faulty, obtain the target diagnostic information involved in the fault location of the link to be tested; The diagnostic data corresponding to different diagnostic access permissions are determined from the target diagnostic information.

14. The method according to any one of claims 1-3, characterized in that, The management wavelength includes at least one of 1310 nm, 1270 nm, and 1330 nm; the service wavelength includes at least one of 1490 nm and 1550 nm. The timing of sending the operation and maintenance management frame based on the management wavelength is located in a preset time slot interval, where the time slot interval is an idle time slot not occupied by the service data transmission. The operation and maintenance management frame includes at least one of the following: error detection frame, delay detection frame, link tracing frame, and loopback frame.

15. A fault location system for optical fibers, characterized in that, The system includes: an optical line terminal and at least one node directly or indirectly connected to the optical line terminal, wherein the node includes: a junction box or an optical distribution node; The optical line terminal is used to perform the method as described in any one of claims 1-14.

16. A fault location device for optical fibers, characterized in that, The device, used as an optical line terminal in a vehicle, comprises: The transmitting module is used to transmit a first detection frame to the link to be tested in the vehicle-mounted optical communication at a preset management wavelength. The first detection frame is a bit error detection frame and / or a delay detection frame. The management wavelength is different from the service wavelength used for service data transmission. The link to be tested includes at least two first nodes, and the first nodes include a junction box or an optical distribution node. The first determining module is used to determine whether the link under test is faulty based on the first response information received corresponding to the link under test; The second determining module is used to determine the faulty fiber segment in the link under test based on the second response information corresponding to the loopback frame sent to the link under test when the link under test has a fault.

17. A vehicle, characterized in that, The vehicle includes: an optical line terminal for performing the method as described in any one of claims 1-14; Alternatively, the optical fiber fault location system as described in claim 15.

18. An optical line terminal, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-14.

19. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions; When the computer execution instructions are executed by the processor, they are used to implement the method as described in any one of claims 1-14.

20. A computer program product, characterized in that, The product includes: computer programs; When the computer program is executed by a processor, it is used to implement the method as described in any one of claims 1-14.

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