Optical cable online monitoring method, system and equipment

Abstract

The invention relates to an optical cable online monitoring method, system and equipment, and belongs to the technical field of optical cable detection. Comprising the following steps: configuring a working mode of an OTDR module according to a monitoring requirement; the working mode comprises at least one of a positioning function mode, a light source function mode and an optical power monitoring function mode; controlling the optical switch module to be switched to a target channel, and establishing an optical signal transmission link between the to-be-monitored optical fiber connected with the channel and the OTDR module; the OTDR module processes according to a configuration mode: in a positioning mode, a pulse is sent to an optical fiber through a target channel, and an optical signal is demodulated to generate a characteristic curve after being returned; in the light source mode, light is continuously emitted, and light signals are sequentially output from channels of the optical switch; in an optical power monitoring mode, the optical switch changes channels, optical fiber optical signals are transmitted to the OTDR module, power is detected, loss abnormity is judged by comparing a threshold, and finally a monitoring result is obtained. According to the invention, the connection is simplified, the monitoring consistency is ensured, the monitoring accuracy of the optical cable state is improved, the cost can be effectively reduced, and the equipment size is reduced.

Description

Technical Field

[0001] This invention relates to the field of optical cable testing technology, and in particular to an online monitoring method, system and equipment for optical cables. Background Technology

[0002] In the field of optical cable construction, maintenance and monitoring, in order to ensure the stable operation of optical fiber links, it is necessary to use professional equipment to monitor key performance indicators such as attenuation, fault points and loss distribution of optical fiber links. At present, the mainstream monitoring equipment mainly includes optical time-domain reflectometer (OTDR) and optical power monitoring (OPM).

[0003] The working principle of OTDR is as follows: laser pulses are emitted into the optical fiber, and the backscattered Rayleigh scattering signal and reflected signal generated when the laser pulse is transmitted in the optical fiber are measured to generate attenuation and reflection characteristic curves distributed along the optical fiber. Based on the analysis of these characteristic curves, performance information such as uniformity, defects, breaks, and joint coupling of the optical fiber link can be obtained, thereby realizing optical fiber attenuation measurement, joint loss calculation, optical fiber fault location, and optical fiber loss distribution monitoring along the length direction. It is a core diagnostic tool in the field of optical cable monitoring. However, OTDRs have inherent limitations: First, to ensure test performance, multiple pulses need to be sent and the test data needs to be averaged to generate characteristic curves, resulting in long test times. Second, since the backscattered Rayleigh signal in optical fiber is extremely weak (approximately -80dB / ns at a wavelength of 1550nm), high-precision optoelectronic devices such as high-power lasers, high-performance photodetectors, and high-speed, low-noise analog amplifier circuits are required, resulting in high equipment costs. Third, although in practical applications, one OTDR can be expanded into a system capable of monitoring N optical fiber links (N being the number of optical switch ports) by using optical switches to share the cost, this expansion method requires polling each optical fiber link for monitoring. The polling time increases with the number of optical switch ports and the requirements for test performance, making it impossible to achieve real-time monitoring of optical fiber networks.

[0004] OPM (Optical Power Detection and Management) monitors the optical link by continuously monitoring the optical power and its changes in the received optical signal. A preset threshold for optical power change is used; when the monitored optical power change exceeds this threshold, a fault in the fiber optic link can be identified (such as a loose connector, a new bend in the fiber affecting communication performance, or a broken fiber). From a hardware perspective, OPM consists of a photodetector, a transimpedance amplifier (TIA), an analog-to-digital converter (ADC), a controller, and a memory. Its workflow is as follows: the photodetector receives the optical signal from the optical interface and converts it into a photocurrent signal. The photocurrent is amplified into a voltage signal by the TIA. The ADC converts the analog voltage signal into a digital signal and transmits it to the controller. The controller performs averaging and filtering on the digital signal, and the processing results can be stored in the memory, uploaded to a host computer via the communication interface, or displayed to the user. However, OPM applications rely on the cooperation of the light source at the other end of the fiber optic link. The light source at the other end needs to emit the optical signal and transmit it to the OPM. Furthermore, OPM can only monitor the magnitude of loss changes in the fiber optic link and cannot identify the type or location of the fault.

[0005] In existing optical cable monitoring networks, although OTDR and OPM modules can be deployed simultaneously, their control logic and workflow are independent, and they can only perform fault location and status detection functions separately. The specific deployment scheme is as follows: two optical fibers are required to monitor one optical cable. The OTDR and the light source (OLS) required for optical power monitoring are deployed at one end of the optical cable, and the OPM module is deployed at the other end. During normal operation, the OPM monitors the optical power in real time to determine the link status. When the OPM detects an anomaly, receives a manual instruction, or reaches a preset scheduling cycle, it activates the OTDR to diagnose the type and location of the link fault.

[0006] Although the existing systems mentioned above possess basic capabilities for fault location (OTDR) and condition detection (OPM), they still have significant shortcomings in practical engineering applications, severely limiting their widespread use in large-scale, high-real-time monitoring scenarios. Specific deficiencies are as follows: High connection complexity: OTDR and OPM each require an independent optical fiber to achieve monitoring functions, which makes the on-site construction process such as optical cable wiring and equipment connection complicated. This not only increases the workload of construction, but also increases the risk of connection failures during construction.

[0007] Poor monitoring consistency: Since OTDR and OPM use different optical fibers for monitoring, if the optical cable to be monitored consists of multiple segments with branches in the middle, the OTDR may monitor one branch while the OPM monitors another branch. This results in the monitoring data of the two not being able to reflect the true operating status of the same optical cable, making it difficult to achieve accurate monitoring of the optical cable link.

[0008] Cost and size issues are prominent: The functions of OTDR and OPM are implemented by independent devices or boards, without forming an integrated design. This not only leads to high costs for equipment procurement, deployment and maintenance, but also requires more installation space, making it less suitable for scenarios with limited installation environments. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to overcome the problems of complex connection, poor monitoring consistency, high cost and large device size in the prior art.

[0010] Firstly, to solve the above-mentioned technical problems, the present invention provides an online monitoring method for optical cables, comprising: Configure the operating mode of the OTDR module according to the monitoring requirements; wherein the operating mode includes at least one of the positioning function mode, the light source function mode, and the optical power monitoring function mode. The optical switch module is controlled to switch to the target channel, and an optical signal transmission link is established between the optical fiber to be monitored connected to the target channel and the OTDR module. The OTDR module processes the data according to the configured working mode to obtain the monitoring results of the optical fiber to be monitored. Wherein, if the working mode is the positioning function mode, the OTDR module processing procedure is as follows: the OTDR module emits an optical pulse, the optical pulse is output to the optical fiber to be monitored through the target channel; the optical fiber to be monitored emits an optical signal, the optical signal is transmitted back to the OTDR module through the optical switch module; the OTDR module demodulates the optical signal and generates an OTDR characteristic curve; If the operating mode is the light source function mode, the OTDR module processing procedure is as follows: the OTDR module continuously emits a continuous optical signal; the continuous optical signal is sequentially output from each channel of the optical switch module to the corresponding optical fiber to be monitored; If the operating mode is the optical power monitoring function mode, the OTDR module processing procedure is as follows: control the optical switch module to switch to each channel in sequence, and transmit the optical signals of the optical fibers to be monitored connected to each channel to the OTDR module respectively; the OTDR module performs optical power detection on each optical signal to obtain the optical power data of each optical fiber to be monitored; and determines whether there is any loss abnormality in the optical fiber link to be monitored based on the optical power data and the preset threshold.

[0011] In one embodiment of the present invention, if the working mode is a light source function mode, while the OTDR module continuously emits a continuous light signal, it also includes setting the channel switching parameters of the optical switch module. The channel switching parameters include the channel switching time and the signal holding time of each channel. Based on the channel switching time and the signal holding time of each channel, the interval time for the optical switch module to switch each channel is obtained.

[0012] Secondly, to solve the above-mentioned technical problems, the present invention provides an online optical cable monitoring system for implementing the above-mentioned online optical cable monitoring method, comprising: The system includes a control module, an OTDR module, and an optical switch module; the control module is connected to both the OTDR module and the optical switch module; and the optical switch module is connected to the OTDR module.

[0013] In one embodiment of the present invention, a light source module is further included, which is connected to the control module and the optical switch module respectively; the optical switch module is a 2:N optical switch, with its first common terminal connected to the OTDR module and its second common terminal connected to the light source module.

[0014] In one embodiment of the present invention, the OTDR module includes a laser driver, a laser, a coupler, a first photodetector, a first transimpedance amplifier, and a first analog-to-digital converter connected in sequence; wherein the laser driver and the first analog-to-digital converter are both connected to the control module; and the coupler is connected to the optical switch module.

[0015] In one embodiment of the present invention, an optical power measurement module is further included, which is connected to the control module; the control module controls the optical power measurement module to receive optical power signals from the outside and detects the optical power signals to determine whether there is a fault in the optical cable.

[0016] In one embodiment of the present invention, the optical power measurement module includes a second analog-to-digital converter and M parallel branches; wherein each of the parallel branches includes a second photodetector and a receiving circuit, all of the receiving circuits are connected to the second analog-to-digital converter, and the second analog-to-digital converter is connected to the control module.

[0017] In one embodiment of the present invention, the optical power measurement module includes a second analog-to-digital converter, a multiplexer, and M parallel branches; wherein each of the parallel branches includes a second photodetector and a receiving circuit; all the receiving circuits are connected to the multiplexer, and the multiplexer is connected to the second analog-to-digital converter.

[0018] In one embodiment of the present invention, the optical power measurement module includes a second analog-to-digital converter, a multiplexer, a receiving circuit, and M parallel branches; wherein each of the parallel branches includes a second photodetector; all the second photodetectors are connected to the multiplexer, the multiplexer is connected to the receiving circuit, and the receiving circuit is connected to the second analog-to-digital converter.

[0019] Thirdly, to solve the above-mentioned technical problems, the present invention provides an online optical cable monitoring device, including the above-mentioned online optical cable monitoring system.

[0020] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: (1) The online monitoring method, system, and device for optical cables described in this invention can flexibly configure the working mode of the OTDR module according to specific needs, covering at least one of the positioning function mode, light source function mode, and optical power monitoring function mode. This not only effectively reduces equipment costs but also simplifies installation steps and complexity. Compared with traditional multi-device fiber splitting monitoring schemes, this invention avoids data deviations caused by equipment differences, ensures the consistency of monitoring data, and significantly improves the accuracy of optical cable status assessment. Specifically, this invention generates characteristic curves by emitting optical pulses and receiving feedback signals, which can quickly and accurately locate optical fiber fault points. Its OLS function can provide stable continuous optical signals, ensuring the quality and stability of communication signals. The OPM function can achieve millisecond-level rapid fault warning, monitor optical power in real time, and judge abnormal loss, thus promptly discovering potential problems in the optical fiber link.

[0021] (2) The optical cable online monitoring system constructed by this invention includes two forms: one is an optical cable online monitoring system with OTDR and OLS functions; the other adds OPM function on this basis to form a more comprehensive optical cable online monitoring system. Both forms of the system can effectively reduce equipment size, reduce equipment cost, occupy less equipment room space, and facilitate large-scale deployment. Attached Figure Description

[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Figure 1 This is a flowchart of an online monitoring method for optical cables according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the first optical cable online monitoring system in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the OTDR module structure in a preferred embodiment of the present invention; Figure 4This is a schematic diagram of the second type of online optical cable monitoring system in a preferred embodiment of the present invention; Figure 5 This is a schematic diagram of the third type of online optical cable monitoring system in a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the fourth type of online optical cable monitoring system in a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the optical cable online monitoring system structure obtained by the first design method in the third optical cable online monitoring system of the preferred embodiment of the present invention; Figure 8 This is a schematic diagram of the optical cable online monitoring system structure obtained by the second design method in the third optical cable online monitoring system of the preferred embodiment of the present invention; Figure 9 This is a schematic diagram of the optical cable online monitoring system structure obtained by the third design method in the third type of optical cable online monitoring system in the preferred embodiment of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0025] Example 1: Reference Figure 1 As shown, this embodiment of the invention provides an online monitoring method for optical cables, including but not limited to the following steps: S1. Configure the working mode of the OTDR module according to the monitoring requirements; the working mode includes at least one of the following: positioning function mode, light source function mode, and optical power monitoring function mode; S2. Control the optical switch module to switch to the target channel and establish an optical signal transmission link between the optical fiber to be monitored connected to the target channel and the OTDR module; The S3 and OTDR modules process the data according to the configured working mode to obtain the monitoring results of the optical fiber to be monitored. When the operating mode is the positioning function mode, the OTDR module processing procedure is as follows: the OTDR module emits an optical pulse, which is output to the fiber to be monitored through the target channel; the fiber to be monitored emits an optical signal, which is transmitted back to the OTDR module through the optical switch module; the OTDR module demodulates the optical signal and generates an OTDR characteristic curve. When the operating mode is the light source function mode, the OTDR module processing procedure is as follows: the OTDR module continuously emits a continuous optical signal; the continuous optical signal is sequentially output from each channel of the optical switch module to the corresponding optical fiber to be monitored; If the working mode is optical power monitoring mode, the OTDR module process is as follows: the control optical switch module switches to each channel in sequence, and the optical signals of the optical fibers to be monitored connected to each channel are transmitted to the OTDR module respectively; the OTDR module performs optical power detection on each optical signal to obtain the optical power data of each optical fiber to be monitored; based on the optical power data and the preset threshold, it is determined whether there is any loss abnormality in the optical fiber link to be monitored.

[0026] The online optical cable monitoring method described in this invention allows for flexible configuration of the OTDR module's operating mode according to specific needs, encompassing at least one of the following: positioning function mode, light source function mode, and optical power monitoring function mode. This effectively reduces equipment costs and simplifies installation steps and complexity. Simultaneously, it avoids data deviations caused by equipment differences in traditional multi-device fiber splitting monitoring schemes, ensuring the consistency of monitoring data and significantly improving the accuracy of optical cable condition assessment. Specifically, the OTDR function enables second-level fault location by generating characteristic curves through the transmission of optical pulses and the reception of return signals, quickly and accurately locating fiber optic fault points; the OLS function provides stable continuous optical signals, ensuring the quality and stability of communication signals; and the OPM function achieves millisecond-level rapid fault early warning, monitoring optical power in real time and identifying abnormal losses, promptly detecting potential problems in the optical fiber link. This design not only significantly improves monitoring efficiency and accuracy but also reduces the number of devices and maintenance costs, providing strong support for the stable and efficient operation of optical fiber communication systems.

[0027] Specifically, the OTDR module has flexible mode configuration capabilities. It can be switched to OTDR function (i.e., positioning function), OLS function (i.e., light source function) or OPM function (i.e., optical power monitoring function) by pre-setting. In networking scenarios, this method can also be pre-configured as a combination of OTDR and light source, or a combination of OTDR and OPM, to adapt to different monitoring needs.

[0028] Specifically, in step S3, the process by which the OTDR module processes data according to the configured operating mode includes: When in OTDR mode, the optical switch module is first switched to target channel i, and then the OTDR test process is initiated. The OTDR module emits an optical pulse, which is output through the i-th channel of the optical switch module and transmitted to the optical fiber connected to that channel. Return signals generated in the optical fiber (such as Rayleigh scattering signals, Fresnel reflection signals, etc.) return along the original path, are received by the OTDR module after passing through the optical switch module, and then demodulated to generate a complete OTDR curve for analyzing the characteristics of the optical fiber link. In this mode, the optical switch module is a 1:N (with N channels) optical switch.

[0029] In the OLS functional mode, the laser driver that drives the OTDR module keeps the laser emitting continuously. At the same time, through the precise control of the optical switch module, the continuous optical signal emitted by the OTDR module is output in turn from each port of the optical switch according to the time sequence; to ensure the stability and orderliness of the optical signal output, clear channel switching parameters are usually set.

[0030] Further, in the embodiment of the present invention, the channel switching parameters of the optical switch module are set, and the parameters include the channel switching time T1 and the signal holding time T2 of each channel; according to the channel switching time and the signal holding time of each channel, the interval time for the optical switch module to switch each channel is obtained.

[0031] Exemplarily, the interval time for the optical switch module to switch each channel is the sum of the channel switching time T1 and the signal holding time T2 of each channel, that is, T1 + T2.

[0032] When it is in the OPM functional mode, the channels are also switched in turn by controlling the optical switch module, so that the receiving circuit can receive the optical signals from different channels in turn, thereby completing the optical power detection of each channel.

[0033] Further, if the corresponding peer device in the OPM functional mode also adopts the same architecture and is configured in the OLS mode, it is necessary to control the sampling time T3 of the OPM to ensure the detection effectiveness. The conditions that the sampling time T3 satisfies include: when the optical switch switching time T1 is less than the channel holding time T2 (i.e., T1 < T2), the sampling time T3 needs to satisfy the condition of being less than (T1 + T2) / 2; when T1 is greater than or equal to T2 (i.e., T1 ≥ T2), the sampling time T3 needs to satisfy the requirement of being less than T2 / 2, so as to ensure that the sampling process can accurately capture the effective optical signal output by the peer OLS.

[0034] Further, according to the optical power data and the preset threshold, it is judged whether there is an abnormal loss in the fiber optic link to be monitored. The judgment criterion is whether the optical power data exceeds the preset threshold. If it exceeds, it indicates that there is a fault in the optical cable; if it does not exceed, there is no fault in the optical cable.

[0035] The optical cable online monitoring method described in the embodiment of the present invention can flexibly implement the OTDR function, the OLS function, or simultaneously implement the three functions of OTDR, OLS, and OPM. This method effectively reduces the equipment cost, simplifies the installation steps and operation complexity, and realizes the millisecond-level fast fault warning of OPM and the second-level OTDR fault location on a single optical fiber at the same time.

[0036] Embodiment 2: Based on the same inventive concept, this embodiment provides an online optical cable monitoring system. The principle of solving the problem is similar to that of the online optical cable monitoring method provided in Embodiment 1, and the repeated parts will not be described again.

[0037] Reference Figure 2 As shown, this embodiment provides an online optical cable monitoring system for implementing the online optical cable monitoring method provided in Embodiment 1, including: The system includes a control module, an OTDR module, and an optical switch module. The control module is connected to both the OTDR module and the optical switch module. The optical switch module is connected to the OTDR module.

[0038] Specifically, refer to Figure 3 As shown, the OTDR module includes a laser driver, a laser, a coupler, a first photodetector, a first transimpedance amplifier, and a first analog-to-digital converter connected in sequence. The laser driver and the first analog-to-digital converter are both connected to the control module; the coupler is connected to the optical switch module. Furthermore, the OTDR module includes a circulator for controlling the transmission direction of the optical signal. This circulator is connected to both the laser and the first photodetector.

[0039] Specifically, the execution flow of the OTDR module is as follows: the laser driver drives the laser to generate a laser pulse signal (i.e., an optical pulse). The optical pulse is output to the optical fiber through the circulator. After passing through the fault location in the optical fiber, the optical pulse forms a reflected / scattered optical signal. The reflected / scattered optical signal reaches the first photodetector PD through the optical fiber and the circulator. The first photodetector PD converts the reflected / scattered optical signal into a current signal. The first transimpedance amplifier TIA then amplifies the current signal and converts it into a voltage signal (i.e., an analog signal). The first analog-to-digital converter ADC converts the analog voltage signal into a digital signal.

[0040] It should be noted that traditional OTDR modules typically have a built-in controller, which connects to the laser driver and the analog-to-digital converter (ADC). This controller generates OTDR curves through demodulation to determine the location and / or type of fiber optic faults. To improve the stability of the monitoring system in this embodiment and reduce the failure rate, the OTDR module and optical switch module may not have separate controllers. Instead, the control module in this embodiment serves as the system control center, simplifying the internal processes, reducing the failure rate, and improving system stability. Alternatively, the OTDR module and optical switch module can also have their own built-in controllers. In this case, the control module indirectly controls the OTDR or OLS functions by sending commands to its built-in controller.

[0041] This embodiment provides four types of online optical cable monitoring systems, specifically: the first type is an online optical cable monitoring system that shares an OTDR laser and a photodetector (hereinafter referred to as the first type of online optical cable monitoring system); the second type is an online optical cable monitoring system that uses a separate light source (hereinafter referred to as the second type of online optical cable monitoring system); the third type is an online optical cable monitoring system that uses a separate optical power measurement module (hereinafter referred to as the third type of online optical cable monitoring system, which further includes three different subtypes); and the fourth type is an online optical cable monitoring system that uses a separate optical power measurement module and an independent light source (hereinafter referred to as the fourth type of online optical cable monitoring system).

[0042] Specifically, refer to Figure 2 As shown, for the first type of online optical cable monitoring system, the optical switch module preferably adopts a 1:N optical switch to adapt to the multi-channel optical fiber monitoring requirements. In this system, the control module can implement functional regulation of the OTDR module, allowing it to flexibly switch between OTDR, OLS, or OPM functions. Specifically, in OTDR mode, the control module controls the 1:N optical switch module to switch to channel i, starting the OTDR module test. The OTDR module emits light pulses through its built-in laser detector. The emitted light pulses are output from the i-th channel (port) of the 1:N optical switch to the corresponding optical fiber in the optical cable. The signal returned from the optical fiber is received by the OTDR module after passing through the 1:N optical switch, and demodulated to generate an OTDR curve. In OLS mode, the control module controls the laser driver of the OTDR module to continuously drive the laser to emit light. The control module controls the 1:N optical switch to make the continuous optical signal emitted by the OTDR module output from each channel (port) of the 1:N optical switch in a time-division manner. The preferred control method of this system is as follows: assuming the 1:N optical switch switching time is T1, the holding time of each channel is set to T2, therefore the channel interval time is T1+T2.

[0043] In this embodiment, the first type of online optical cable monitoring system, while possessing both OTDR and OLS functions, can significantly reduce the overall size of the equipment. The core reason is that the OTDR module, in addition to its own OTDR function, directly utilizes a built-in laser to perform OLS functions, eliminating the need for an additional independent light source. This greatly improves system integration and thus achieves a miniaturized design.

[0044] Specifically, refer to Figure 4As shown, for the second type of online optical cable monitoring system, a light source module is added to the first system structure. This light source module is connected to both the control module and the optical switch module. The light source module includes a laser driver and a laser, with the laser driver and laser electrically connected. In this system, the optical switch module is preferably a 2:N optical switch, with its first common terminal connected to the OTDR module and its second common terminal connected to the light source module. This dual common terminal design enables optical path switching and collaborative operation between the OTDR module and the independent light source module.

[0045] Furthermore, the light source module can include two or more lasers with different wavelengths. These multiple lasers are connected to the second common port of a 2:N optical switch via a coupler. The coupler can be a beam splitter or a wavelength division multiplexer (WDM). Regarding the wavelength configuration of the light source module, there are two core scenarios: First, when the light source contains one or more laser wavelengths, one laser can be selected to have the same wavelength as the laser in the OTDR module, or all the lasers in the light source can have different wavelengths than the laser in the OTDR module. If a different wavelength configuration is used, the laser in the OTDR module can be used as an additional OLS (light source). This application method is consistent with the design logic of the first type of online optical cable monitoring system (a system sharing an OTDR laser and a photodetector). Secondly, when the light source module contains multiple laser wavelengths, the following two working modes can be flexibly selected in practical applications: one is to use a fixed wavelength as the OLS light source; the other is to use time-division control to sequentially send optical signals of different wavelengths as the OLS light source. Both modes can meet the functional requirements of fiber optic line monitoring and adapt to the monitoring accuracy and coverage requirements of different scenarios. In addition, since the attenuation characteristics, fault performance, and sensitivity to bending of optical fibers in optical cables are strongly dependent on the wavelength of the transmitted light, for example, optical fibers may attenuate at 1310nm, 1550nm, or 1625nm, if only tested at a single laser wavelength, information on attenuation spectrum anomalies may be missed. Therefore, the light source design in this embodiment uses multiple lasers of different wavelengths to enable the OTDR module to more comprehensively evaluate the performance of the optical cable.

[0046] Furthermore, the specific connection structure of the second type of online optical cable monitoring system is as follows: the control module is connected to the OTDR module, the 2:N optical switch and the light source module respectively. Figure 4 The online monitoring system for optical cables shown in this embodiment is preferably deployed at one end of the optical cable to be monitored, while an OPM device can be deployed at the other end of the optical cable to monitor it. Figure 4 The optical signal emitted by the OLS function in the online optical cable monitoring system shown.

[0047] Furthermore, the specific control steps of the second type of online optical cable monitoring system are as follows: In OTDR function mode, the control module controls the i-th channel of the 2:N optical switch to connect to the first common terminal, initiating the OTDR test. The OTDR module emits optical pulses, which are output from the 2:N optical switch through the first common port to the corresponding optical fiber via the i-th channel. The signal returning from the optical fiber is received by the OTDR module after passing through the 2:N optical switch and demodulated to generate an OTDR curve. In OLS function mode, the control module controls the laser driver in the light source module to drive the laser to emit light. The control module controls each channel connected by the 2:N optical switch to connect to the second common port, allowing the optical signal emitted by the light source module to be output from each channel of the 2:N optical switch in a time-division manner. The preferred control method for this system is as follows: assuming the 2:N optical switch switching time is T1, and the hold time for each channel is set to T2, then the channel interval time is set to T1+T2.

[0048] Specifically, refer to Figure 5 As shown, for the third type of online optical cable monitoring system, an optical power measurement module (OPM module) is added to the structure of the first type of online optical cable monitoring system. The OPM module is connected to the control module, and the control module controls the OPM module to receive optical power signals from the outside and detect the optical power signals to determine whether there is a fault in the optical cable.

[0049] Furthermore, the specific connection structure of the third type of online optical cable monitoring system is as follows: the control module is connected to the OTDR module, the optical switch module, and the OPM module respectively, and the common terminal of the optical switch module is connected to the OTDR module. Preferably, the optical switch module in this system is a 1:N optical switch.

[0050] It should be noted that in the third type of online optical cable monitoring system, the OTDR module can implement OLS functionality. Since the specific implementation of OTDR and OLS functions in this system is consistent with the functional implementation logic of the first type of online optical cable monitoring system, it will not be elaborated further here to avoid redundancy.

[0051] Furthermore, when implementing the OPM function in the third type of online optical cable monitoring system, the control module controls the OPM module to receive optical power signals from the outside and detects the optical power signals to determine whether there is a fault in the optical cable. Specifically, the fault detection is whether the optical power signal exceeds a threshold. If it exceeds the threshold, the optical cable is faulty; if it does not exceed the threshold, the optical cable is not faulty.

[0052] The reason why the OTDR module is built into the optical cable online monitoring system in this embodiment is that the third type of optical cable online monitoring system can realize the functions of OTDR, OLS and OPM at one measurement point, which can effectively reduce the complexity of the entire detection system in multi-site optical cable detection.

[0053] Specifically, refer to Figure 6 As shown, the fourth type of online optical cable monitoring system, based on the first type, also includes a light source module and an optical power measurement module (OPM module), thus simultaneously possessing OTDR, OLS, and OPM functions. Specifically, the system includes a control module, an OTDR module, an optical switch module, a light source module, and an OPM module, wherein the control module is connected to the OTDR module, optical switch module, light source module, and OPM module respectively. The optical switch module is preferably a 2:N optical switch, with its first common terminal connected to the OTDR module and its second common terminal connected to the light source module to achieve optical path coordination among multiple modules.

[0054] It should be noted that the OTDR, OLS, and OPM functions implemented by the fourth type of online optical cable monitoring system are the same as those of the above-mentioned online optical cable monitoring systems, and will not be described again here.

[0055] Specifically, the third type of online optical cable monitoring system, which employs a separate optical power measurement module, further comprises three different subtypes. Specifically, refer to... Figures 7 to 9 As shown, all three subtypes include a control module, a 1:N optical switch, an OTDR module, and an OPM module. The OTDR module is connected to the control module, the 1:N optical switch, and the OPM module. The control module is connected to the laser driver in the OTDR module, which in turn is connected to the laser. The laser is connected to the coupler. The coupler is connected to the first photodetector (PD). The first photodetector (PD), the first transimpedance amplifier (TIA), and the first analog-to-digital converter (ADC) are connected sequentially. The first ADC is connected to the control module. The control module is connected to the 1:N optical switch. The 1:N optical switch is connected to the coupler. Furthermore, multiple lasers can be configured. Figure 7 (Given only one example) Multiple lasers of different wavelengths can be coupled using a wavelength division multiplexer; the coupler can be a beam splitter or a circulator. Furthermore, the three different subtypes of online optical cable monitoring systems also include a storage module connected to the control module, which stores data monitored by the OTDR module and the OPM module.

[0056] Furthermore, the core difference between the three subtypes mentioned above lies in the differentiated design of the OPM module. The design methods of the OPM module for each of the three subtypes are as follows: First design approach: Refer to Figure 7As shown, the OPM module includes a second analog-to-digital converter (ADC) and M parallel branches. Each branch includes a second photodetector (PD) and a receiving circuit. All receiving circuits are connected to the second ADC, which is in turn connected to the control module. The second ADC can be a multi-channel ADC or a single-channel ADC. Specifically, when using a multi-channel ADC, each receiving circuit can directly occupy one independent channel of that ADC to achieve parallel signal conversion. When using a single-channel ADC, a multiplexer (MUX) is needed for channel switching, allowing multiple receiving circuits to occupy the single-channel ADC in a time-sharing manner to complete the sequential conversion of signals from each circuit. During the operation of the optical cable online monitoring system, the control module processes the received signals (e.g., averaging, filtering) and stores them in the storage module. Users can view the data stored in the storage module at any time via a host computer. Furthermore, the receiving circuit includes a current-to-voltage amplifier circuit (such as a transimpedance amplifier circuit), and a voltage amplifier circuit can be selected as needed. The core function of the current-to-voltage amplifier circuit is to convert the weak photocurrent output by the second photodetector PD into a processable voltage signal and complete the initial amplification.

[0057] The second design approach: (Refer to...) Figure 8 As shown, the OPM module includes a second analog-to-digital converter (ADC), a multiplexer, and M parallel branches. Each branch includes a second photodetector (PD) and a receiving circuit. All receiving circuits are connected to the multiplexer (MUX), which is connected to the second ADC. The second ADC is connected to the control module. The second ADC is a single-channel ADC. In this design, the OPM module uses parallel receiving circuits but shares one channel of the second ADC.

[0058] The second design approach, by employing a single-channel ADC, effectively reduces the number of second analog-to-digital converters (ADCs). From a hardware cost and circuit design perspective, the cost and circuit area occupied by second ADCs are far higher than those of multiplexers (MUX). Therefore, reducing the number of second ADCs directly brings multiple advantages: first, it simplifies circuit routing and reduces wiring complexity; second, it reduces the overall PCB board area and improves device integration; and third, it reduces the need for supporting components such as reference voltage sources and decoupling capacitors, thereby reducing hardware costs, minimizing component failure points, further improving system reliability, and ultimately achieving a dual reduction in design complexity and production costs.

[0059] The third design approach: (Refer to...) Figure 9As shown, the OPM module includes a second analog-to-digital converter (ADC), a multiplexer, a receiving circuit, and M parallel branches. Each branch includes a second photodetector (PD). All PDs are connected to a multiplexer (MUX), which is connected to a receiving circuit. The receiving circuit is connected to the second ADC, which is connected to the control module. The second ADC is a single-channel ADC.

[0060] The second design requires multiple receiving circuits. However, due to the influence of hardware manufacturing processes and device characteristics, the electrical parameters of each receiving circuit will inevitably have slight differences. Even if calibration is completed during system initialization, these differences will still drift with fluctuations in ambient temperature and over long-term use, ultimately leading to inherent errors in the measurement results of different channels that are difficult to eliminate. To address this core issue, the third design optimizes the circuit topology by swapping the connection positions of the multiplexer (MUX) and the receiving circuits. This improved solution has significant advantages: firstly, it fundamentally reduces the error interference caused by differences and drift in the parameters of multiple receiving circuits, greatly improving the measurement accuracy of optical cable monitoring data; secondly, it reduces the overall number of receiving circuits, minimizing hardware procurement and design costs to the greatest extent.

[0061] The four optical cable online monitoring system designs described in this embodiment all have differentiated technical advantages and applicable scenarios. In practical applications, the corresponding system configuration can be flexibly selected according to specific monitoring needs (such as requirements for measurement accuracy, project cost budget, and focus of core functions) to achieve the optimal balance between performance and cost-effectiveness.

[0062] Example 3: This embodiment provides an online monitoring device for optical cables, including an online monitoring system for optical cables provided in Embodiment 2.

[0063] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0064] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0065] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0066] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0067] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for online monitoring of optical cables, characterized in that, include: Configure the OTDR module's operating mode according to monitoring requirements; The operating modes include at least one of the following: positioning function mode, light source function mode, and optical power monitoring function mode; The optical switch module is controlled to switch to the target channel, and an optical signal transmission link is established between the optical fiber to be monitored connected to the target channel and the OTDR module. The OTDR module processes the data according to the configured working mode to obtain the monitoring results of the optical fiber to be monitored. Wherein, if the working mode is the positioning function mode, the OTDR module processing procedure is as follows: the OTDR module emits an optical pulse, the optical pulse is output to the optical fiber to be monitored through the target channel; the optical fiber to be monitored emits an optical signal, the optical signal is transmitted back to the OTDR module through the optical switch module; the OTDR module demodulates the optical signal and generates an OTDR characteristic curve; If the operating mode is the light source function mode, the OTDR module processing procedure is as follows: the OTDR module continuously emits a continuous optical signal; the continuous optical signal is sequentially output from each channel of the optical switch module to the corresponding optical fiber to be monitored; If the operating mode is the optical power monitoring function mode, the OTDR module processing procedure is as follows: control the optical switch module to switch to each channel in sequence, and transmit the optical signals of the optical fibers to be monitored connected to each channel to the OTDR module respectively; the OTDR module performs optical power detection on each optical signal to obtain the optical power data of each optical fiber to be monitored; and determines whether there is any loss abnormality in the optical fiber link to be monitored based on the optical power data and the preset threshold.

2. The online monitoring method for optical cables according to claim 1, characterized in that, When the operating mode is the light source function mode, the OTDR module continuously emits a continuous light signal while also setting the channel switching parameters of the optical switch module. The channel switching parameters include the channel switching time and the signal holding time of each channel. Based on the channel switching time and the signal holding time of each channel, the interval time for the optical switch module to switch each channel is obtained.

3. An online monitoring system for optical cables, used to implement the method described in any one of claims 1 to 2, characterized in that, include: The system includes a control module, an OTDR module, and an optical switch module; the control module is connected to both the OTDR module and the optical switch module. The optical switch module is connected to the OTDR module.

4. The online monitoring system for optical cables according to claim 3, characterized in that, It also includes a light source module, which is connected to the control module and the optical switch module respectively; the optical switch module is a 2:N optical switch, with its first common terminal connected to the OTDR module and its second common terminal connected to the light source module.

5. The online monitoring system for optical cables according to claim 3, characterized in that, The OTDR module includes a laser driver, a laser, a coupler, a first photodetector, a first transimpedance amplifier, and a first analog-to-digital converter connected in sequence; wherein the laser driver and the first analog-to-digital converter are both connected to the control module; and the coupler is connected to the optical switch module.

6. The online monitoring system for optical cables according to claim 3, characterized in that, It also includes an optical power measurement module, which is connected to the control module; the control module controls the optical power measurement module to receive optical power signals from the outside and detects the optical power signals to determine whether there is a fault in the optical cable.

7. The online monitoring system for optical cables according to claim 6, characterized in that, The optical power measurement module includes a second analog-to-digital converter and M parallel branches; each of the parallel branches includes a second photodetector and a receiving circuit, all of which are connected to the second analog-to-digital converter, which is connected to the control module.

8. The online monitoring system for optical cables according to claim 6, characterized in that, The optical power measurement module includes a second analog-to-digital converter, a multiplexer, and M parallel branches; each of the parallel branches includes a second photodetector and a receiving circuit; all the receiving circuits are connected to the multiplexer, and the multiplexer is connected to the second analog-to-digital converter.

9. The online monitoring system for optical cables according to claim 6, characterized in that, The optical power measurement module includes a second analog-to-digital converter, a multiplexer, a receiving circuit, and M parallel branches; each of the parallel branches includes a second photodetector; all the second photodetectors are connected to the multiplexer, the multiplexer is connected to the receiving circuit, and the receiving circuit is connected to the second analog-to-digital converter.

10. An online monitoring device for optical cables, characterized in that, Includes the online monitoring system for optical cables as described in any one of claims 3 to 9.

Images