Optical cable monitoring with external trigger function system and method thereof

Abstract

An optical cable monitoring with external trigger function system and method thereof are provided, the method includes performing polling scans on each monitoring core wire according to a set period; determining whether an optical cable fault message sent by a transmission system network management is received; conducting OTDR measurement and locate the faults based on the analysis of the measurement results with GIS map on the monitoring core wires in a fault cable; determining whether the monitoring core wires in the fault cable detects a fault; reporting to the transmission system network management that the OTDR measures no fault when no fault is measured; and sending alarms to the transmission system network management, network maintenance system and message sending system when the fault is measured.

Description

[Technical Field]

[0001] This invention relates to an optical cable monitoring system and method, and more particularly to an optical cable monitoring system and method with external triggering function. [Previous Technology]

[0002] Fiber optic cable monitoring systems are commonly known in the market as RFTS (Remote Fiber Test System). An RFTS consists of a Remote Test Unit (RTU) and a Test System Controller (TSC). The TSC manages the RTUs deployed in various data centers. The RTUs can use an Optical Time Domain Reflectometer (OTDR) with an optical channel selector to facilitate the measurement of multiple fiber optic routes. The TSC can be integrated with a Geographic Information System (GIS) via built-in or external methods to perform fault location analysis and send various alarms (such as via email, SMS, or App) to transmit fiber optic cable fault alarm information to relevant maintenance systems and personnel.

[0003] The following explanation uses Figure 1 as an example. In the equipment room, there are transmission equipment and RTUs. Optical cables are connected to the transmission equipment and RTUs via an Optical Line Distribution Frame (OLDF). The optical fiber core connected to the transmission equipment is called the transmission core or usage core, and the optical fiber core connected to the RTU is called the monitoring core. In Figure 1, the RTU of the RFTS uses a 1550nm remote light source and an optical power meter for normal optical fiber route monitoring. When an obstacle is detected, the OTDR uses a 1625nm monitoring wavelength to measure the obstacle point. The two different wavelengths are coupled to the monitoring core of the RFTS using a Wavelength Division Multiplexing (WDM).

[0004] The operating principle is as follows:

[0005] 1. When the RTU detects an abnormal change in optical power that exceeds the set threshold value, it will send an optical power alarm to the TSC host.

[0006] 2. The TSC host will then perform OTDR measurements on the obstacle fiber routing indicator RTU.

[0007] 3. Based on the measurement results, locate the obstacle map data and then send an alarm message.

[0008] In Figure 1, the RFTS is responsible for monitoring the non-used core lines of the optical cable (in Figure 1, the RFTS-monitored core lines of the optical cable are indicated by thick lines). When a fault occurs in the RFTS-monitored core line, a fault alarm can be quickly issued to facilitate subsequent rapid repair. The transmission system network management monitors the transmission quality of the used core lines (in Figure 1, the used core lines of the optical cable are indicated by thin lines). It can analyze the information provided by the transmission equipment to detect faults in the optical cable. However, subsequent fault location can only rely on maintenance personnel to conduct manual inspection on-site. This inefficient operation method may lead to delays in fault notification. Therefore, when a fault occurs in a core line of the optical cable that is not monitored by the RFTS, i.e., the transmission core line or the unmonitored non-used core line, the RFTS is unaware of it and cannot quickly notify for repair.

[0009] In other words, the existing optical cable monitoring system and transmission system are two independent systems.

[0010] Another type of optical cable monitoring system that uses a polling monitoring mechanism may encounter problems in real time when the same OTDR polls too many optical fiber routes. Although the transmission system network management can quickly detect optical cable obstacles, it also cannot quickly locate the obstacle. [Summary of the Invention]

[0011] This invention provides an optical cable monitoring system and method with external triggering function. When the transmission system network management determines that there is an optical cable fault, the optical cable monitoring system is triggered from the outside to perform an OTDR scan on the monitoring core line of the optical cable. When used for online monitoring, it can quickly locate the fault point of the transmission core line and improve the circuit service quality. When used for offline monitoring, it can know the quality status of all monitoring core lines at that time, so as to facilitate subsequent decision-making and handling.

[0012] This invention provides an optical cable monitoring system with external triggering function, electrically or communicatively connected to a transmission system. The optical cable monitoring system includes an interfacing transmission system unit, a control server, an interfacing control unit, a fault information analysis unit, an alarm sending unit, and a plurality of RTUs. The transmission system includes a transmission system network management system, multiple transmission devices, and optical cables disposed between the transmission devices. The optical cable includes a monitoring core line. The control server is communicatively connected to the RTUs to set a polling period. The RTUs poll and measure the monitoring core line according to the polling period to obtain quality information of the monitoring core line. When the transmission system network management system determines that an optical cable fault has occurred, it transmits the faulty optical cable information to the interfacing transmission system unit of the optical cable monitoring system. The interfacing control unit is electrically or communicatively connected to the interfacing transmission system unit, the fault information analysis unit, and the control server, respectively, to receive the faulty optical cable information transmitted via the interfacing transmission system unit and transmit the faulty optical cable information to the control server. The control server sends OTDR measurement commands to the RTUs according to the faulty optical cable information. The RTU is used for online monitoring, measuring only the obstruction transmission core in the obstructed optical cable according to the OTDR measurement command. For offline monitoring, it measures all monitoring cores of the obstructed optical cable according to the OTDR measurement command to obtain measurement information. This measurement information is then transmitted to the obstruction information analysis unit via the control server and the interfacing control unit. The obstruction information analysis unit uses the measurement information to locate the obstruction map and obtain obstruction map location information. The alarm sending unit is electrically or communicatively connected to both the interfacing transmission system unit and the obstruction information analysis unit, and receives and sends alarm messages based on the obstruction map location information.

[0013] The present invention provides a fiber optic cable monitoring method with external triggering function, applied to a fiber optic cable monitoring system electrically or communicatively connected to a transmission system. The fiber optic cable monitoring system includes an interfacing transmission system unit, a control server, an interfacing control unit, a fault information analysis unit, an alarm sending unit, and a plurality of RTUs. The transmission system includes a transmission system network management system, multiple transmission devices, and fiber optic cables disposed between the transmission devices. The fiber optic cable includes a monitoring core line. The fiber optic cable monitoring method includes: setting a polling period via the control server, and polling and measuring the monitoring core line via the RTUs according to the polling period to obtain quality information of the monitoring core line; when the transmission system network management system determines that a fiber optic cable fault has occurred, transmitting the fault fiber optic cable information to the interfacing transmission system of the fiber optic cable monitoring system via the transmission system network management system. The transmission system unit receives faulty optical cable information via the interfacing control unit and transmits the faulty optical cable information to the control server; the control server sends OTDR measurement commands to the RTU based on the faulty optical cable information; during online monitoring, the RTU measures only the faulty transmission core line in the faulty optical cable according to the OTDR measurement commands; during offline monitoring, the RTU measures all monitoring core lines of the faulty optical cable according to the OTDR measurement commands to obtain measurement information, and the RTU transmits the measurement information to the fault information analysis unit via the control server and the interfacing control unit; the fault information analysis unit performs fault map location based on the measurement information and obtains fault map location information; and the alarm sending unit receives and sends alarm messages based on the fault map location information.

[0014] Based on the above, the present invention provides an optical cable monitoring system and method with external triggering function, which can perform periodic measurements on each monitoring route to obtain optical cable quality information. The RTU no longer needs additional optical power monitoring components, but instead relies on the transmission system network management to determine whether the optical cable is obstructed. When the transmission system network management determines that the optical cable is obstructed, it can externally trigger the optical cable monitoring system to perform OTDR scanning on the monitoring core line of the optical cable. In online monitoring, the obstruction point of the transmission core line can be quickly located, solving the problem of slow manual location and improving circuit service quality. In offline monitoring, the quality status of all monitoring core lines at that time can be known to facilitate subsequent decision-making and handling. The OTDR scanning object can be the transmission core line providing service or the unused core line, i.e., dark fiber, which can be flexibly configured according to the needs of network operators. The more core lines scanned, the better the current status of obstructed optical cables can be understood. Furthermore, this invention utilizes the optical cable monitoring system's ability to monitor optical cable routes, and uses statistical values ​​generated from multiple measurements to examine the rationality of the existing optical cable route's reference trajectory and monitoring quality threshold. The dynamic feedback system adjusts the monitoring quality parameters, thereby improving monitoring efficiency.

[0015] In order to make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below, and detailed descriptions are given in conjunction with the accompanying drawings.

Implementation Method

[0016] Some embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Component symbols used in the following description are considered the same or similar components when they appear in different drawings. These embodiments are only a part of the present invention and do not disclose all possible implementations of the present invention.

[0017] Figure 2 is an architecture diagram of an optical cable monitoring system with external triggering function according to an embodiment of the present invention.

[0018] Referring to Figure 2, the optical cable monitoring system 100 with external triggering function is electrically or communicatively connected to the transmission system 200, the network maintenance system 300, and the message sending system 400, respectively. The optical cable monitoring system 100 may include an interfacing transmission system unit 160, a control server 110, an interfacing control unit 120, a fault information analysis unit 130, an alarm sending unit 140, and a plurality of remote test units (RTUs) 150. In this embodiment, the RTU 150 may include RTU devices 1501, 1502, ..., 150n.

[0019] The transmission system 200 may include a transmission system network management system 210, multiple transmission devices, and optical cables installed between the transmission devices. The optical cables may include monitoring core lines. Monitoring core lines may include transmission core lines or unused core lines. Optical cable monitoring may include online monitoring and offline monitoring. Online monitoring refers to monitoring the transmission core lines in use within the optical cable. Offline monitoring refers to monitoring the unused core lines within the optical cable, i.e., dark fiber. In this embodiment, the transmission devices may include transmission devices 2201…transmission device 220m.

[0020] Among them, the control server 110 is connected to the RTU150 for communication, and the polling period can be set. The RTU150 can poll and measure the monitoring center line according to the polling period to obtain the quality information of the monitoring center line.

[0021] When the transmission system network management 210 determines that an optical cable fault has occurred, it transmits the faulty optical cable information to the interfacing transmission system unit 160 of the optical cable monitoring system 100.

[0022] The interfacing transmission system unit 160 is a communication interface used to connect the transmission system network management unit 210, the interfacing control unit 120 and the alarm sending unit 140. It can be used to identify the faulty optical cable information from the transmission system network management unit 210 and forward it to the interfacing control unit 120. It can also report the scanning results of the alarm sending unit 140 back to the transmission system network management unit 210.

[0023] In one embodiment, the interface protocol between the transmission system unit 160 and the transmission system network management system 210 adopts Extensible Markup Language (XML) and Hypertext Transfer Protocol (HTTP) POST, etc., and the main parameters are alarm ID, fault occurrence time, optical cable name and core number, response scan fault alarm or repair, scan time, event point latitude and longitude, and nearest equipment room name. This invention is not limited thereto.

[0024] The interfacing control unit 120 is electrically or communicatively connected to the interfacing transmission system unit 160, the obstacle information analysis unit 130, and the control server 110, respectively. It can receive and identify obstacle fiber optic cable information transmitted via the interfacing transmission system unit 160, and transmit the obstacle fiber optic cable information to the control server 110. Alternatively, the interfacing control unit 120 can transmit alarms received by the control server 110 from the RTU 150 or measurement information received by the control server 110 to the obstacle information analysis unit 130.

[0025] In one embodiment, the interface protocol between the interfacing transmission system unit 160 and the interfacing control unit 120 adopts XML or other protocols, and the main parameters are the optical cable name and core number, the type of obstacle, and the repair method. This invention is not limited thereto.

[0026] In one embodiment, the interface between the control unit 120 and the control server 110 uses the following protocols: uplink protocol: socket or others; main parameters: optical cable name and core number, fault type and repair. Downlink protocol: POST or other protocols; main parameters: optical cable name and core number, fault or repair, fault point length, OTDR scan waveform. This invention is not limited thereto.

[0027] The control server 110 can identify obstructed optical cable information from the transmission system network management 210, manage the RTU 150 to which it belongs through the IP network and VPN network, store the monitoring core line information of the managed optical cable, and send optical time domain reflectometer (OTDR) measurement commands to the RTU 150 according to the obstructed optical cable information. When monitoring online, the RTU 150 can measure only the obstructed transmission core line in the obstructed optical cable according to the OTDR measurement command. When monitoring offline, it can measure all monitoring core lines of the obstructed optical cable according to the OTDR measurement command to obtain measurement information, and transmit the measurement information to the obstruction information analysis unit 130 through the control server 110 and the interfacing control unit 120.

[0028] In one embodiment, the interface protocol between the management server 110 and the RTU 150 may be a network socket, a REST API (Representational State Transfer Application Programming Interface), or others, and the main parameters are the route number, OTDR measurement parameters, OTDR scan waveform, and scan event table. This invention is not limited thereto.

[0029] The obstacle information analysis unit 130 can locate the obstacle map data based on the measurement information and obtain obstacle map data location information.

[0030] In one embodiment, the obstacle information analysis unit 130 can locate the obstacle point of the obstacle transmission core line based on the measurement information, so as to obtain obstacle map positioning information. In another embodiment, the obstacle information analysis unit 130 can obtain the quality information of all monitoring core lines of the obstacle optical cable based on the measurement information, and determine whether an obstacle monitoring core line appears among all monitoring core lines based on the quality information. When it is determined that an obstacle monitoring core line appears among all monitoring core lines, the obstacle monitoring core line is located to obtain the obstacle point position information of the obstacle monitoring core line as obstacle map positioning information.

[0031] Specifically, the RTU150 can scan all the monitoring cores of the obstructed optical cable one by one according to the OTDR measurement command, and then transmit the measurement information of each monitored core (including the distance to the obstruction point, the quality status of the monitoring core, etc.) back to the obstruction information analysis unit 130. The obstruction information analysis unit 130 will compare and analyze the received measurement information (obstruction point distance) with the map information built into the geographic map system (which may include the location information of each optical cable, such as street information, etc.) to find out the specific location or coordinates of the obstruction point of the obstructed optical cable, thereby locating the obstruction point of the obstruction core and obtaining the obstruction point location information of the obstruction core as obstruction map location information.

[0032] The alarm sending unit 140 is electrically or communicatively connected to the interfacing transmission system unit 160 and the obstacle information analysis unit 130, respectively, and can receive and send alarm messages based on obstacle map location information.

[0033] In one embodiment, the interface protocol between the alarm sending unit 140 and the interfacing transmission system unit 160 is HTTP POST or other protocols, and the main parameters are optical cable name and core number, response scan fault alarm or repair, scan time, event point latitude and longitude, and nearest equipment room name. This invention is not limited thereto.

[0034] In one embodiment, when no obstruction monitoring line appears among all monitoring lines, the alarm sending unit 140 only reports the measurement of obstruction information to the transmission system network management 210.

[0035] In another embodiment, when an obstacle monitoring line appears among all the monitoring lines, the alarm sending unit 140 sends the obstacle map location information to the transmission system network management 210, the network maintenance system 300 and the message sending system 400 respectively.

[0036] RTU150 may include multiple RTU devices, which can receive instructions from the control server 110 to perform online and offline monitoring of the core line, or can perform polling measurements according to the period set by the control server 110, and can send alarms when a routing obstacle is detected.

[0037] The following examples, in conjunction with Figures 6 and 7, illustrate how to dynamically adjust optical cable quality monitoring parameters based on the optical cable condition. These parameters include a reference trajectory and quality thresholds. This not only improves monitoring efficiency but also allows for the determination of whether any obstructed monitoring lines exist among all monitored lines based on quality information.

[0038] Figure 6 is a flowchart of dynamically adjusting optical cable quality monitoring parameters according to an embodiment of the present invention. Figure 7 is a schematic diagram of the measured values ​​and Gaussian distribution according to an embodiment of the present invention.

[0039] In step S310, the control server 110 can establish an OTDR reference trajectory.

[0040] In step S320, the control server 110 can set a quality threshold.

[0041] In step S330, the control server 110 can calculate the average value of the OTDR trajectory for each measurement and the standard deviation of the monitoring quality threshold, and accumulate the number of alarm occurrences. When the monitoring core line is in the event of a broken line, severe obstruction, or other accident, the statistics and alarm count should be suspended to avoid data distortion.

[0042] In step S340, the control server 110 can compare the average value of the OTDR trajectory with the OTDR reference trajectory to determine whether the OTDR reference trajectory is reasonable. In one embodiment, when the number of measurements exceeds 30, the average measurement value gradually converges and stabilizes. At this time, the average value of the OTDR trajectory measurement can be compared with the measurement value of the OTDR reference trajectory. The closer the two are, the more reasonable the OTDR reference trajectory is considered. When a certain threshold is exceeded, the OTDR reference trajectory can be considered unrepresentative or unreasonable.

[0043] Please refer to Figure 7. In one embodiment, the original reference trajectory routing attenuation value (A value) of a certain optical cable was 12dB, and the quality threshold was 3dB. Due to the harsh environment causing the optical cable to age prematurely, the average test trajectory routing attenuation value fell to 14dB (B value).

[0044] The reference trajectory is known to have a serious deviation from the average test trajectory (BA=2dB). Since BA=2dB is close to the quality threshold of 3dB, RFTS100 will automatically reset the reference trajectory to reduce the alarm frequency.

[0045] When it is determined that the OTDR reference trajectory is not representative or is unreasonable, in step S360, the control server 110 can adjust the OTDR reference trajectory. Since the reference trajectory has changed, the statistical values ​​and alarm counts need to be recalculated and a new benchmark needs to be established. After adjusting the OTDR reference trajectory, the process returns to step S330. In one embodiment, when the OTDR reference trajectory is not representative or is unreasonable (e.g., due to post-line repair, line reconnection, or fiber optic cable degradation), the OTDR can be restarted to reset the OTDR reference trajectory; or it can be set using the average waveform of the trajectory over a period of time. Since the reference trajectory has changed, the statistical values ​​and alarm counts need to be recalculated.

[0046] In step S350, when the OTDR reference trajectory is deemed reasonable, the control server 110 can compare the alarm occurrence probability formed by the quality threshold and standard deviation with the short-term alarm occurrence rate to determine whether the quality threshold is reasonable. In one embodiment, the setting of the quality threshold takes into account two factors: first, event discrimination, for example, the reasonable attenuation value of an event is a certain number of dB, and if the quality threshold is too large, it will not be detected; second, the quality threshold should be set as a multiple of the standard deviation, and the alarm occurrence probability can be estimated statistically. The former is the basis for event discrimination, and the latter can only be considered after it is met. When the short-term alarm occurrence rate in a short period of time (such as one month) reaches a certain difference from the statistically estimated alarm occurrence probability, and exceeds a certain threshold, the quality threshold needs to be adjusted. Setting the quality threshold according to needs (such as optical cable aging) will affect the frequency of subsequent alarm occurrences.

[0047] The following description is based on specific embodiments and Figure 7.

[0048] In one embodiment, the routing reference trajectory attenuation value is 30dB, and the quality threshold is 4dB. When the trajectory measurement value is greater than or equal to 34dB (i.e., 30+4) or less than or equal to 26dB (i.e., 30-4), the optical cable monitoring system 100 generates an alarm. The alarm occurrence probability is 1 - the probability that the trajectory measurement value is between the upper and lower quality thresholds, or 2 * (the probability that the trajectory measurement value ranges from -∞ to (average value - quality threshold value)), and its formula is 2 * P (z ≦ -1 * quality threshold value / standard deviation), where P is the standard normal cumulative distribution function. Assuming the statistical standard deviation is 1.2, the alarm occurrence probability is 0.0858%. If the average alarm occurrence rate in the most recent month is 3%, it is significantly high. Therefore, the quality threshold value needs to be adjusted to 5dB to reduce the alarm occurrence probability, and the values ​​and alarm counts need to be recalculated.

[0049] When the quality threshold is deemed unreasonable, in step S370, the control server 110 can adjust the quality threshold. The quality threshold can be set according to requirements (such as optical cable aging), which will affect the frequency of subsequent alarms. Since the quality threshold has been changed, the statistical values ​​and alarm counts need to be recalculated and the baseline needs to be re-established. After adjusting the quality threshold, the system returns to step S330.

[0050] When the quality threshold is determined to be reasonable, return to step S330.

[0051] In one embodiment, when constructing an optical cable, the control server 110 can establish a reference trajectory and set a quality threshold for the monitoring core line. The quality threshold refers to the tolerance range of the test OTDR trajectory relative to the reference trajectory, such as the relative optical loss value of a single event, the relative optical loss value of the entire route, or the relative length change value. If the quality threshold is set too low, frequent false alarms are easily generated due to the equipment itself or external environmental factors, making maintenance personnel overworked. If the quality threshold is set too high, it is impossible to detect when a real fault occurs. Therefore, the reference trajectory must be reasonably representative, and the quality threshold must also be within a reasonable range. This invention proposes to use the statistical normal distribution method, as shown in Figure 7. When the number of measurements is sufficient (e.g., at least 30 measurements), the average measurement value should be close to the measurement value of the reference trajectory. The quality threshold is proportional to the standard deviation, and an alarm is triggered if the quality threshold is exceeded. Through statistical numerical feedback, the optical cable quality monitoring parameters are dynamically adjusted to improve monitoring efficiency.

[0052] Figure 3 is a schematic diagram of offline monitoring of an optical cable monitoring system according to an embodiment of the present invention.

[0053] Please refer to Figure 3 for an example of offline monitoring using the optical cable monitoring system 100, wherein the control server 110 has the function of managing the RTU 150 and maintaining optical cable data.

[0054] In step S1, when the transmission system network management 210 determines that an optical cable fault has occurred, it transmits the faulty optical cable information to the interfacing transmission system unit 160.

[0055] In step S2, the interfacing transmission system unit 160 transmits the obstruction optical cable information to the control server 110 via the interfacing control unit 120. The control server 110 sends an OTDR measurement command to the RTU150, instructing the RTU150 to perform an OTDR scan on the monitoring core of the obstruction optical cable.

[0056] In step S3, after the RTU150 performs an OTDR scan, it reports the scan results to the control server 110.

[0057] In step S4, the control server 110 transmits the scan results to the obstacle information analysis unit 130 via the interfacing control unit 120 for obstacle map location. The obstacle information analysis unit 130 transmits the obstacle analysis results to the alarm sending unit 140, and then processes them according to the following scenarios:

[0058] In step S5a, if an obstacle is found in the RFTS monitoring core line (the core line marked with a thick line in Figure 3), obstacle location alarm information is provided to the relevant network maintenance system 300, message sending system 400, and transmission system network management 210. If multiple RFTS monitoring core lines are found to be obstructed, the alarm for each core line is processed in the same way as above, that is, obstacle location alarm information is provided to the relevant network maintenance system 300, message sending system 400, and transmission system network management 210.

[0059] In step S5b, if the result of scanning the RFTS monitoring core line is normal and no fault alarm is generated, it is only necessary to report the scan result of the transmission system network management 210 as having no fault. If the scan results of multiple RFTS monitoring core lines are normal, the report for each core line is processed in the same way as above, that is, it is only necessary to report the scan result of the transmission system network management 210 as having no fault.

[0060] In Figure 3, RFTS100 is used for offline monitoring, allowing the transmission system network management 210 to monitor the quality status of the RFTS monitoring cores. If a fiber optic cable fault only damages some cores, and some RFTS monitoring cores are in good condition, the faulty transmission cores can be reconnected to the good RFTS monitoring cores to maintain the service provided by the original transmission cores. For some important fiber optic cables, all unused cores can be included in RFTS monitoring to improve circuit service quality. If the fiber optic cable damage is severe enough to cause all RFTS monitoring cores to break, then a repair unit must be called for emergency repairs.

[0061] Figure 4 is a schematic diagram of online and offline monitoring of an optical cable monitoring system according to an embodiment of the present invention.

[0062] Please refer to Figure 4. The RFTS100 can perform both online and offline monitoring simultaneously.

[0063] During online monitoring, every transmission core line is included in the monitoring. When the transmission system network management 210 determines that there is a fault in the optical cable, the control server 110 will start the OTDR to scan the transmission core line of the fault for real-time and accurate fault location. Other transmission core lines do not need to be scanned if no fault notification is issued, so as to save the usage time of the OTDR.

[0064] When a transmission core failure occurs during offline monitoring, the status of unused cores at that time is unknown, so every monitored core must be scanned. Including all unused cores in the monitoring can expand the coverage of optical cable monitoring.

[0065] The following description is based on a specific embodiment. In this embodiment, we take a domestic submarine cable with a total of 24 core wires, 3 of which are broken, 15 of which are used for circuit transmission, leaving only 6 unused core wires. Among them, the 15 transmission core wires and the 6 unused core wires are included in the monitoring.

[0066] When the transmission system network management 210 reports a fault in one of the transmission core lines, the RFTS100 can locate the fault using obstacle map data and send an alarm. If the transmission system network management 210 reports a fault in five of the transmission core lines, the RFTS100 will perform an OTDR scan on these five transmission core lines.

[0067] The RFTS100 will perform an OTDR scan on each of the six unused core wires and report the results to the network management system 210. If four of the unused core wires are found to be unobstructed, the user can arrange for the core wires to be reconnected. The RFTS100 will also send an alarm for the two obstructed unused core wires.

[0068] Figure 5 is a schematic diagram of the internal structure of an RTU device according to an embodiment of the present invention.

[0069] Please refer to Figure 5 for the internal structure of the RTU device. The RTU device 150x (i.e., the first RTU) and the transmission device 220x are located in the same equipment room. The transmission device 220x (i.e., the first transmission device) is the receiving end in the transmission direction. x is a number between 1 and m and n, where m and n are positive integers. The RTU device 150y (i.e., the second RTU) and the transmission device 220y are located in the same equipment room. The transmission device 220y (i.e., the second transmission device) is the transmitting end in the transmission direction. y is a number between 1 and m and n, whichever is smaller.

[0070] When performing online monitoring, in order to reduce Raman scattering interference, the RTU device is placed at the transmission receiving end. Therefore, the RTU device 150x includes a control module 151x, an OTDR module 152x, a high-pass filter module 153x, an optical channel selector module 154x, and a WDM module 155x.

[0071] The control module 151x is communicatively connected to the management server 110 and is responsible for functions such as monitoring process control, data analysis, and storage. The control module 151x can perform OTDR scanning according to the set polling cycle, and can also perform measurements according to the instructions of the management server 110. For example, it can receive the polling cycle setting or OTDR measurement command from the management server 110 to control the OTDR module 152x to perform polling measurements on the monitoring core line according to the polling cycle setting, or to control the OTDR module 152x to measure the obstructed optical cable.

[0072] The OTDR module 152x is electrically or communicatively connected to the control module 151x for measuring and monitoring the condition of the center line and for receiving instructions from the control module 151x to perform measurements.

[0073] The high-pass filter module 153x is connected to the OTDR module 152x via fiber optic connection to protect the OTDR module 152x from damage by light sources other than the monitoring wavelength emitted by the OTDR module 152x.

[0074] The optical channel selector module 154x is electrically or communicatively connected to the control module 151x and optically connected to the high-pass filter module. It is used to select different monitoring cores during OTDR measurement, so that the OTDR module 152x can measure multiple monitoring cores.

[0075] The WDM module 155x is connected to the transmission device 220x and the optical channel selector module 154x for communication, and is used to couple the transmission wavelength with the monitoring wavelength to perform online monitoring of the transmission core.

[0076] The RTU device 150y is located in the transmission transmitting end equipment room and includes a low-pass filter module 156y that is communicatively connected to the WDM module 155x via a transmission core line. The low-pass filter module 156y can filter out the monitoring wavelength to protect the transmission equipment 220y. If offline monitoring is performed, there is no need to consider the transmission directionality issue, and the WDM module 155x and the low-pass filter module 156y will not be needed.

[0077] In one embodiment of the present invention, the interfacing transmission system unit 160, the management server 110, the interfacing management unit 120, the obstacle information analysis unit 130, the alarm sending unit 140, the transmission system network management unit 210, the control module 151x, the OTDR module 152x, and the optical channel selector module 154x are implemented using a central processing unit (CPU) or other programmable general-purpose or special-purpose microprocessors. In another embodiment of the present invention, the interfacing transmission system unit 160, the management server 110, the interfacing management unit 120, the obstacle information analysis unit 130, the alarm sending unit 140, the transmission system network management unit 210, the control module 151x, the OTDR module 152x, and the optical channel selector module 154x may also be implemented using the same processor and loaded with different modules; the present invention is not limited thereto.

[0078] The interfacing transmission system unit 160, the control server 110, the interfacing control unit 120, the fault information analysis unit 130, the alarm sending unit 140, the transmission system network management unit 210, the control module 151x, the OTDR module 152x, and the optical channel selector module 154x can be implemented through software, firmware, hardware circuits, optical components, or any combination thereof, and this disclosure does not limit the implementation method of the interfacing transmission system unit 160, the control server 110, the interfacing control unit 120, the fault information analysis unit 130, the alarm sending unit 140, the transmission system network management unit 210, the control module 151x, the OTDR module 152x, and the optical channel selector module 154x.

[0079] The optical cable monitoring method of the present invention will be described below with reference to the various devices, components and modules shown in FIG2. The various processes in FIG8 may be adjusted according to the implementation situation, and are not limited thereto.

[0080] Figure 8 is a flowchart of an optical cable monitoring method according to an embodiment of the present invention.

[0081] Refer to Figure 8. In step S810, the RFTS100 performs polling scans on each monitoring core line according to the set period. The period can be set to be longer based on user experience, mainly to know the quality status of each monitoring core line.

[0082] In step S820, RFTS100 determines whether it has received an obstacle fiber optic cable message sent by the transmission system network management 210. If RFTS100 receives an obstacle fiber optic cable message sent by the external transmission system network management 210, due to its immediacy and high priority to the system, it will interrupt the original polling scan order and execute step S830. If RFTS100 does not receive an obstacle fiber optic cable message sent by the external transmission system network management 210, it will continue polling scans according to the original order.

[0083] In step S830, RFTS100 performs OTDR measurement and obstacle map location analysis on the monitoring core wires in the obstacle optical cable. If it is online monitoring, only the transmission core wire of this obstacle needs to be measured; if it is offline monitoring, all monitoring core wires of this obstacle optical cable need to be measured.

[0084] In step S840, it is determined whether the monitoring core wire in the obstacle optical cable has detected the obstacle.

[0085] If the monitoring core line in the obstructed optical cable does not detect the obstruction, in step S850, it is only necessary to report that the transmission system network management 210OTDR has no obstruction, and then return to step S810 to resume the normal polling scan.

[0086] If the monitoring core line in the faulty optical cable detects a fault, in step S860, an alarm and fault location information are sent to the transmission system network management 210, the network maintenance system 300 and the message sending system 400, and then the process returns to step S810 to resume the normal polling scan.

[0087] Based on the above, the present invention provides an optical cable monitoring system and method with external triggering function, which can perform periodic measurements on each monitoring route to obtain optical cable quality information. The RTU no longer needs additional optical power monitoring components, but instead relies on the transmission system network management to determine whether the optical cable is obstructed. When the transmission system network management determines that the optical cable is obstructed, it can externally trigger the optical cable monitoring system to perform OTDR scanning on the monitoring core line of the optical cable. In online monitoring, the obstruction point of the transmission core line can be quickly located, solving the problem of slow manual location and improving the circuit service quality. In offline monitoring, the quality status of all monitoring core lines at that time can be known to facilitate subsequent decision-making and handling. The OTDR scanning object can be the transmission core line providing service or the unused core line, i.e., dark fiber, which can be flexibly configured according to the needs of network operators. The more core lines scanned, the better the current status of obstructed optical cables can be understood. Furthermore, this invention utilizes the optical cable monitoring system's ability to monitor optical cable routes, and uses statistical values ​​generated from multiple measurements to examine the rationality of the existing optical cable route's reference trajectory and monitoring quality threshold. The dynamic feedback system adjusts the monitoring quality parameters, thereby improving monitoring efficiency.

[0088] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0089] Figure 1 is a schematic diagram of the operation of a traditional optical cable monitoring system and a transmission system. Figure 2 is an architecture diagram of an optical cable monitoring system with external triggering function according to an embodiment of the present invention. Figure 3 is a schematic diagram of offline monitoring of an optical cable monitoring system according to an embodiment of the present invention. Figure 4 is a schematic diagram of online and offline monitoring of an optical cable monitoring system according to an embodiment of the present invention. Figure 5 is a schematic diagram of the internal structure of an RTU device according to an embodiment of the present invention. Figure 6 is a flowchart of dynamically adjusting optical cable quality monitoring parameters according to an embodiment of the present invention. Figure 7 is a schematic diagram of the measured values ​​and Gaussian distribution according to an embodiment of the present invention. Figure 8 is a flowchart of an optical cable monitoring method according to an embodiment of the present invention.

Claims

1. A fiber optic cable monitoring system with external triggering function, electrically or communicatively connected to a transmission system, the fiber optic cable monitoring system comprising an interfacing transmission system unit, a control server, an interfacing control unit, a fault information analysis unit, an alarm sending unit, and a plurality of remote test units (RTUs), the transmission system comprising a transmission system network management system, multiple transmission devices, and fiber optic cables disposed between the transmission devices, the fiber optic cable including a monitoring core line, wherein the control server is communicatively connected to the RTUs for setting a polling period, the RTUs polling and measuring the monitoring core line according to the polling period to obtain quality information of the monitoring core line, and when the transmission system network management system determines that a fiber optic cable fault has occurred, the transmission system network management system transmits the fault fiber optic cable information to the interfacing transmission system unit of the fiber optic cable monitoring system. The interfacing control unit is electrically or communicatively connected to the interfacing transmission system unit, the obstacle information analysis unit, and the control server. The main parameters of the interface between the interfacing control unit and the interfacing transmission system unit are the optical cable name and core wire number, obstacle type, and repair information. The interfacing control unit receives the obstacle optical cable information transmitted via the interfacing transmission system unit and transmits it to the control server. The main parameters of the uplink protocol in the interface between the interfacing control unit and the control server are the optical cable name and core wire number, obstacle type, and repair information; the main parameters of the downlink protocol are the optical cable name and core wire number, obstacle or repair, obstacle point length, and OTDR scan waveform. The control server identifies the obstacle optical cable information to determine the optical cable name and core wire number, obstacle type, and repair information, and sends Optical Time Domain Reflectometer (OTDR) measurement commands to the RTUs based on the obstacle optical cable information. These RTUs are used to measure only the obstructed transmission core of the obstructed optical cable according to the OTDR measurement command during online monitoring, and to measure all monitoring cores of the obstructed optical cable according to the OTDR measurement command during offline monitoring to obtain measurement information. This measurement information is then transmitted to the obstruction information analysis unit via the control server and the interfacing control unit. The obstruction information analysis unit is used to locate the obstruction point of the obstructed transmission core and all monitoring cores of the obstructed optical cable based on the measurement information, obtaining the location information of the obstruction point as obstruction map location information. The alarm sending unit is electrically or communicatively connected to the interfacing transmission system unit and the obstruction information analysis unit, respectively. The main parameters of the interface protocol between the alarm sending unit and the interfacing transmission system unit are the optical cable name and core number, response scan obstruction alarm or repair, scan time, event point latitude and longitude, and nearest equipment room name.The alarm sending unit receives obstacle map location information from the obstacle information analysis unit and sends an alarm message to the transmission system network management system via the interfacing transmission system unit based on the obstacle map location information.

2. The optical cable monitoring system as described in claim 1, wherein the operation of the obstacle information analysis unit locating the obstacle transmission core and the obstacle point of all monitoring cores of the obstacle optical cable based on the measurement information to obtain the location information of the obstacle point as the obstacle map positioning information, further includes: the obstacle information analysis unit being used to compare the measurement information with the map information built into the geographic mapping system to locate the obstacle point of the obstacle transmission core and obtain the obstacle point coordinates as the obstacle map positioning information; and the obstacle information analysis unit being used to obtain the quality information of all monitoring cores of the obstacle optical cable based on the measurement information, and to determine whether an obstacle monitoring core appears among all monitoring cores based on the quality information, so that when the obstacle monitoring core appears among all monitoring cores, the obstacle monitoring core is located by combining the map information built into the geographic mapping system to obtain the obstacle point location information of the obstacle monitoring core as the obstacle map positioning information.

3. The optical cable monitoring system as described in claim 2, wherein the optical cable monitoring system is electrically or communicatively connected to the message sending system and the network maintenance system respectively, and in the operation of the alarm sending unit receiving and sending the alarm message according to the obstacle map location information, the alarm sending unit is further configured to, when the obstacle monitoring line does not appear among all the monitoring lines, only report the measured obstacle-free information to the transmission system network management system, and the alarm sending unit is further configured to, when the obstacle monitoring line appears among all the monitoring lines, send the obstacle map location information to the transmission system network management system, the network maintenance system and the message sending system respectively.

4. The optical cable monitoring system as described in claim 2, wherein the operation of the control server sending the OTDR measurement command to the RTUs based on the obstructed optical cable information further includes: the control server establishing an OTDR reference trajectory; the control server setting a quality threshold; the control server calculating the average value and standard deviation of the OTDR trajectory for each measurement and counting the number of alarms; the control server comparing the average value of the OTDR trajectory with the OTDR reference trajectory to determine whether the OTDR reference trajectory is reasonable; the control server adjusting the OTDR reference trajectory when it is determined that the OTDR reference trajectory is unreasonable; the control server comparing the alarm occurrence rate formed by the quality threshold and standard deviation with the short-term alarm occurrence rate when it is determined that the OTDR reference trajectory is reasonable, and the control server adjusting the quality threshold when it is determined that the quality threshold is unreasonable.

5. The optical fiber monitoring system as described in claim 1, wherein the RTUs include a first RTU and a second RTU communicatively connected to the first RTU via the optical fiber, the first RTU being communicatively connected to the control server and a first transmission device belonging to the receiving end among the transmission devices, the second RTU being communicatively connected to a second transmission device belonging to the sending end among the transmission devices, and the first RTU and the first transmission device being located in the same equipment room, the second RTU and the second transmission device being located in another equipment room, wherein... The first RTU includes a control module, an OTDR module, a high-pass filter module, an optical channel selector module, and a wavelength division multiplexing (WDM) module. The control module receives the polling period setting or the OTDR measurement command to control the OTDR module to poll and measure the monitoring core line according to the polling period setting, or to control the OTDR module to measure the obstruction optical cable according to the OTDR measurement command. The high-pass filter module transmits the monitoring wavelength from the OTDR module. The optical channel selector module selects the monitoring core line to be measured according to the OTDR measurement. The WDM module couples the transmission wavelength with the monitoring wavelength to perform online monitoring. The second RTU includes a low-pass filter module to filter out the monitoring wavelength.

6. A method for monitoring optical cables with external triggering function, applied in an optical cable monitoring system electrically or communicatively connected to a transmission system, the optical cable monitoring system comprising an interfacing transmission system unit, a control server, an interfacing control unit, a fault information analysis unit, an alarm sending unit, and a plurality of remote test units (RTUs), the transmission system comprising a transmission system network management system, multiple transmission devices, and optical cables disposed between the transmission devices, the optical cable comprising a monitoring core wire, wherein, The optical cable monitoring method includes: setting a polling period via the control server and then using RTUs to poll and measure the monitored core line according to the polling period to obtain quality information of the monitored core line; when the transmission system network management determines that an optical cable fault has occurred, transmitting the faulty optical cable information to the interfacing transmission system unit of the optical cable monitoring system via the transmission system network management; receiving the faulty optical cable information transmitted by the interfacing transmission system unit via the interfacing control unit and transmitting the faulty optical cable information to the control server, wherein the main parameters of the interface between the interfacing control unit and the interfacing transmission system unit are the optical cable name and core line number, fault type and repair; the main parameters of the uplink protocol in the interface between the interfacing control unit and the control server are the optical cable name and core line number, fault type and repair; and the main parameters of the downlink protocol are the optical cable name and core line number, fault or repair, fault point length, and OTDR scan waveform. The control server identifies the obstructed optical cable information to obtain the cable name, core number, obstruction type, and repair requirements. Based on the obstructed optical cable information, it sends optical time domain reflectometer (OTDR) measurement commands to the RTUs. During online monitoring, the RTUs measure only the obstructed transmission core in the obstructed optical cable according to the OTDR measurement commands. During offline monitoring, the RTUs measure all monitored cores of the obstructed optical cable according to the OTDR measurement commands to obtain measurement information. The RTUs then transmit the measurement information to the obstruction information analysis unit via the control server and the interfacing control unit. The obstacle information analysis unit locates the obstacle transmission core and all monitoring cores of the obstacle optical cable based on the measurement information to obtain the location information of the obstacle point as obstacle map location information; and the alarm sending unit receives the obstacle map location information from the obstacle information analysis unit and sends an alarm message to the transmission system network management through the interfacing transmission system unit based on the obstacle map location information. The main parameters of the interface protocol between the alarm sending unit and the interfacing transmission system unit are the optical cable name and core number, response scan obstacle alarm or repair, scan time, event point latitude and longitude, and nearest equipment room name.

7. The optical cable monitoring method as described in claim 6, wherein the step of locating the obstacle transmission core and the obstacle point of all monitoring cores of the obstacle optical cable by the obstacle information analysis unit based on the measurement information to obtain the location information of the obstacle point as the obstacle map positioning information further includes: locating the obstacle point of the obstacle transmission core by the obstacle information analysis unit based on the measurement information and in conjunction with the map information built into the geographic mapping system, obtaining the obstacle point coordinates as the obstacle map positioning information; and obtaining the quality information of all monitoring cores of the obstacle optical cable by the obstacle information analysis unit based on the measurement information, and determining whether an obstacle monitoring core is present among all monitoring cores based on the quality information, so that when the obstacle monitoring core is present among all monitoring cores, the obstacle monitoring core is located in conjunction with the map information built into the geographic mapping system to obtain the obstacle point location information of the obstacle monitoring core as the obstacle map positioning information.

8. The optical cable monitoring method as described in claim 7, wherein the optical cable monitoring system is electrically or communicatively connected to the message sending system and the network maintenance system respectively, and the step of receiving and sending the alarm message through the alarm sending unit according to the obstacle map location information further includes: when the obstacle monitoring line does not appear among all the monitoring lines, the alarm sending unit only reports the measured obstacle-free information to the transmission system network management; and when the obstacle monitoring line appears among all the monitoring lines, the alarm sending unit sends the obstacle map location information to the transmission system network management, the network maintenance system and the message sending system respectively.

9. The optical cable monitoring method as described in claim 7, wherein the step of the control server sending the OTDR measurement command to the RTUs based on the obstructed optical cable information further includes: establishing an OTDR reference trajectory; setting a quality threshold; calculating the average value and standard deviation of the OTDR trajectory for each measurement, and counting the number of alarm occurrences; comparing the average value of the OTDR trajectory with the OTDR reference trajectory to determine whether the OTDR reference trajectory is reasonable; adjusting the OTDR reference trajectory when it is determined that the OTDR reference trajectory is unreasonable; and comparing the alarm occurrence rate formed by the quality threshold and standard deviation with the short-term alarm occurrence rate when the OTDR reference trajectory is determined to be reasonable, and adjusting the quality threshold when it is determined that the quality threshold is unreasonable.

10. The optical cable monitoring method as described in claim 6, wherein the RTUs include a first RTU and a second RTU communicatively connected to the first RTU via the optical cable, the first RTU being communicatively connected to the control server and a first transmission device belonging to the receiving end among the transmission devices, the second RTU being communicatively connected to a second transmission device belonging to the sending end among the transmission devices, and the first RTU and the first transmission device being located in the same equipment room, the second RTU and the second transmission device being located in another equipment room, wherein... The first RTU includes a control module, an OTDR module, a high-pass filter module, an optical channel selector module, and a wavelength division multiplexing (WDM) module. The control module is used to receive a polling period setting or an OTDR measurement command to control the OTDR module to perform polling measurements on the monitoring core line according to the polling period setting, or to control the OTDR module to perform measurements on the obstruction optical cable according to the OTDR measurement command. The high-pass filter module is used to transmit the monitoring wavelength emitted by the OTDR module. The optical channel selector module is used to select the monitoring core line to be measured according to the OTDR measurement. The WDM module is used to couple the transmission wavelength with the monitoring wavelength to perform online monitoring. The second RTU includes a low-pass filter module for filtering out the monitoring wavelength.

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