Device, method and system for detecting port state

Abstract

The invention provides a device, a method and a system for detecting a port state, and belongs to the technical field of optical networks. The device is applied to a point-to-point or multi-point system and comprises a polarized light generation module, a beam combiner and a detector, the polarized light generation module is used for generating and outputting test light in various polarization states to the beam combiner one by one, the power and wavelength of the test light in various polarization states are the same, the wavelength difference of uplink optical signals is smaller than a wavelength difference threshold value, and the detector is used for detecting the wavelength difference of the uplink optical signals. The uplink optical signal is an optical signal sent by an optical terminal device connected with a port to be detected through an optical fiber, the optical combiner and splitter is used for being connected with the optical fiber, sending received test light to the optical fiber and receiving and outputting reflected light transmitted by the optical fiber to the detector, and the detector is used for detecting the received reflected light and outputting the detected reflected light to the port to be detected. And obtaining reflected light detection information corresponding to the test light in each polarization state, wherein the reflected light detection information is used for determining the state of the to-be-detected port. By adopting the device, the port state misjudgment can be reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of optical networks, and in particular to an apparatus, method and system for detecting port status. BACKGROUND

[0002] In a point-to-point or multipoint system, it is usually necessary to detect whether the optical fiber end connected by the port is connected with an optical terminal device. For example, a passive optical network (PON) is composed of an optical line terminal (OLT), an optical distribution network (ODN) and an optical network termination (ONT) connected in sequence. The ODN realizes the transmission of optical signals from the OLT to multiple user terminals through a point-to-multipoint connection. Due to the characteristics of the ODN, such as extensive coverage, a large number of branch optical paths and complex scenes, and the fact that the ODN has no power supply, it is difficult to locate and troubleshoot faults. After the user no longer rents the network of the operator, the user only needs to return the ONT at home, and the other end of the optical cable connected to the operator is still connected to a port of the optical splitter of the operator, which occupies the available resources of the equipment of the operator. Thus, over time, a large number of virtual occupied ports are formed, so it is necessary to identify the status of the port to determine whether the port of the optical splitter is a virtual occupied port.

[0003] In the related art, a direct current test light is input to the optical fiber connected to the port to be detected, and the power of the reflected test light is detected. If the power is greater than a threshold power, it is determined that no optical terminal device is connected, otherwise it is determined that an optical terminal device is connected. The reason is that if the optical fiber end is not connected with an optical terminal device, the reflectivity of the reflection surface formed by the connection head face of the optical fiber end and the air is very large, and the test light reaching this place will form a strong reflection, and the reflected power is large. If the end is connected with an optical terminal device, the reflection of the connection head will be very small, and the reflection is mainly caused by the optical transceiver components inside the optical terminal device, but the reflection is much weaker than the reflection caused by the suspended connection head. However, when the status of the port is determined in this way, when the end is wound or bent with a small radius of curvature, the optical fiber loss will be too large, causing the reflected light to weaken. At this time, if the optical fiber end is not connected with an optical terminal device, the power of the reflected optical signal may also be less than the threshold power, resulting in a misjudgment. SUMMARY

[0004] The present disclosure provides an apparatus, method and system for detecting port status, which can reduce the misjudgment of the port status.

[0005] In a first aspect, this disclosure provides an apparatus for detecting the state of a port. The apparatus is applied to a point-to-point or multi-point system. The apparatus includes a polarization light generation module, a beam combiner / splitter, and a detector. The polarization light generation module generates and outputs test light of multiple polarization states to the beam combiner / splitter, wherein the power and wavelength of the test light of each polarization state are the same, and the wavelength difference between the test light and the uplink optical signal is less than a wavelength difference threshold. The uplink optical signal is an optical signal sent by an optical terminal device connected to the port under test via an optical fiber. The beam combiner / splitter is connected to the optical fiber, transmits the received test light to the optical fiber, and receives and outputs reflected light transmitted through the optical fiber to the detector. The detector detects the received reflected light to obtain reflected light detection information corresponding to each polarization state of the test light. The reflected light detection information corresponding to each polarization state of the test light is used to determine the state of the port under test.

[0006] In the scheme disclosed herein, the detection device sends test light of various polarization states to the optical fiber connected to the port to be tested. If an optical terminal device is connected to the end of the optical fiber, the power of the bidirectional optical component inside the optical terminal device reflecting the test light of different polarization states will have a large difference. Therefore, by using this large difference, it is possible to determine whether an optical terminal device is connected to the end of the optical fiber, thereby obtaining the state of the port to be tested.

[0007] In one alternative embodiment, the polarization light generation module includes a test light generator and an optical polarization controller. The test light generator is used to generate a first test light and send the first test light to the optical polarization controller. The optical polarization controller is used to adjust the polarization state of the first test light one by one to output test light with multiple polarization states one by one.

[0008] In the scheme disclosed herein, when generating test light with multiple polarization states, the test light is generated first, and then the polarization state is adjusted, which enables the acquisition of test light with multiple polarization states of the same wavelength.

[0009] In one alternative approach, the test light is DC light, the optical fiber is plugged into the device, and the detector is used to detect the power of the received reflected light, obtain the power of the reflected light corresponding to each polarization state of the test light, determine a first difference between the maximum power and the minimum power of the reflected light corresponding to the test light of the multiple polarization states, and if the first difference is greater than a first threshold, it is determined that the port to be tested is connected to the optical terminal equipment; if the first difference is not greater than the first threshold, it is determined that the port to be tested is not connected to the optical terminal equipment.

[0010] In the scheme disclosed herein, the power of DC test light reflected by the optical terminal equipment in different polarization states will vary considerably. By measuring the difference between the maximum and minimum power, the state of the port to be tested can be accurately obtained.

[0011] In one alternative approach, the test light is pulsed light, and the device is plugged into the optical fiber or connected to a beam splitter in an optical distribution network. The detector is used to detect the reflected light at the end of the optical fiber to obtain the reflection peak height of the reflected light corresponding to each polarization state of the test light at the end of the optical fiber; determine a second difference between the maximum and minimum reflection peak heights of the reflected light corresponding to the test light of the multiple polarization states; if the second difference is greater than a second threshold, it is determined that the port to be tested is connected to the optical terminal equipment; if the second difference is not greater than the second threshold, it is determined that the port to be tested is not connected to the optical terminal equipment.

[0012] In the scheme disclosed herein, the power of pulsed test light reflected by the optical terminal equipment in different polarization states will vary considerably. By measuring the difference between the maximum and minimum reflection peak heights, the state of the port to be tested can be accurately obtained.

[0013] Secondly, this disclosure provides an apparatus for detecting port status, applicable to point-to-point or multi-point systems. The apparatus includes a pulse light generation module, a beam combiner / splitter, and a detector. The pulse light generation module generates and outputs pulse test light, wherein the wavelength band to which the pulse test light belongs has a reflectivity greater than a reflectivity threshold in a bidirectional optical component, and the pulse width is less than or equal to a target value. The bidirectional optical component is an optical terminal device connected to the port to be detected via an optical fiber. The beam combiner / splitter is connected to the optical fiber, receives the pulse test light, transmits the pulse test light to the optical fiber, and receives and outputs reflected light transmitted through the optical fiber to the detector. The detector is used to determine the first reflection peak information of the reflected light corresponding to the pulse test light at the end of the optical fiber, and the first reflection peak information is used to determine the status of the port to be detected.

[0014] In the scheme disclosed herein, when the port to be tested is connected to an optical terminal equipment, the pulsed test light is transmitted to the optical input of the optical terminal equipment, and the fiber optic connector at the optical input will generate the first reflection. Then, the remaining pulsed test light will be transmitted to the bidirectional optical component of the optical terminal equipment, where a second reflection will be generated. When the port to be tested is not connected to an optical terminal equipment, there will only be one reflection from the fiber optic connector at the optical input. In this way, the status of the port to be tested can be accurately detected by using the reflection peak information.

[0015] In one alternative approach, the detector is used to determine the state of the port to be tested based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light, wherein the reference reflection peak information is the pulse information of the pulsed test light or the reflection peak information generated by the pulsed test light on a single reflective surface.

[0016] In the scheme disclosed herein, when determining the state of the port to be tested, reference reflection peak information generated by a single reflective surface is also considered, which can reduce misjudgments that occur when judging solely by the reflection peak information of the pulse test light.

[0017] In one optional embodiment, the detector is configured to, when the shape of the reflection peak in the first reflection peak information is inconsistent with the shape of the reflection peak in the reference reflection peak information, determine that the port to be detected is connected to the optical terminal device if the difference between the first width and the second width is greater than a target threshold, and determine that the port to be detected is not connected to the optical terminal device if the difference between the first width and the second width is not greater than the target threshold. The first width is the width of the reflection peak in the first reflection peak information at a first position, and the second width is the width of the reflection peak in the reference reflection peak information at the first position. When the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information, determine that the port to be detected is not connected to the optical terminal device.

[0018] In the solution disclosed herein, the state of the port to be detected is determined based on two angles: shape and width at certain locations, thus accurately determining the state of the port to be detected.

[0019] In one alternative approach, the device is connected to the port to be detected via optical fiber or via an optical distribution network.

[0020] Thirdly, this disclosure provides a method for detecting port status, applicable to point-to-point or multipoint systems, the method comprising:

[0021] Test light of multiple polarization states is generated one by one and sent to the optical fiber connected to the port to be tested. The power and wavelength of the test light of multiple polarization states are the same, and the wavelength difference with the uplink optical signal is less than the wavelength difference threshold. The uplink optical signal is the optical signal sent by the optical terminal equipment connected to the optical fiber.

[0022] The reflected light transmitted through the optical fiber is received, and the reflected light is detected to obtain the reflected light detection information corresponding to the test light of each polarization state.

[0023] Based on the reflected light detection information corresponding to the test light of each polarization state, the state of the port to be tested is determined.

[0024] In one alternative approach, test light of various polarization states is generated and transmitted sequentially to the optical fiber connected to the port to be tested, including:

[0025] Generate the first test light;

[0026] The polarization state of the first test light is adjusted one by one to output the test light with the multiple polarization states one by one.

[0027] In one optional approach, the test light is direct current light; determining the state of the port to be tested based on the reflected light detection information corresponding to each polarization state of the test light includes:

[0028] The power of the reflected light is detected to obtain the power of the reflected light corresponding to each polarization state of the test light;

[0029] Determine the first difference between the maximum and minimum power of the reflected light corresponding to the test light in these multiple polarization states;

[0030] If the first difference is greater than the first threshold, then it is determined that the port to be detected is connected to the optical terminal device;

[0031] If the first difference is not greater than the first threshold, it is determined that the port to be tested is not connected to the optical terminal equipment.

[0032] In one alternative approach, the test light is pulsed light;

[0033] Based on the reflected light detection information corresponding to the test light of each polarization state, the state of the port to be detected is determined, including:

[0034] The reflected light at the end of the optical fiber is detected to obtain the reflection peak height of the reflected light corresponding to each polarization state of the test light at the end of the optical fiber.

[0035] Determine the second difference between the maximum and minimum reflection peak heights of the reflected light corresponding to the test light in these multiple polarization states;

[0036] If the second difference is greater than the second threshold, it is determined that the port to be detected is connected to the optical terminal equipment;

[0037] If the second difference is not greater than the second threshold, it is determined that the port to be tested is not connected to the optical terminal equipment.

[0038] Fourthly, this disclosure provides a method for detecting port status, applicable to point-to-point or multipoint systems, the method comprising:

[0039] A pulse test light is generated and sent to the optical fiber connected to the port to be tested. The wavelength of the pulse test light is greater than the reflectivity threshold of the bidirectional optical component and the pulse width is less than or equal to the target value. The bidirectional optical component belongs to the optical terminal device connected to the port to be tested via optical fiber.

[0040] Receive the reflected light transmitted through the optical fiber and determine the first reflection peak information of the reflected light corresponding to the pulse test light at the end of the optical fiber;

[0041] Based on the information from the first reflection peak, the state of the port to be detected is determined.

[0042] In one alternative approach, determining the state of the port to be detected based on the first reflection peak information includes:

[0043] Based on the first reflection peak information and the reference reflection peak information corresponding to the pulse test light, the state of the port to be tested is determined. The reference reflection peak information is the pulse information of the pulse test light or the reflection peak information generated by the pulse test light on a single reflective surface.

[0044] In one alternative approach, determining the state of the port to be tested based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light includes:

[0045] When the shape of the reflection peak in the first reflection peak information is inconsistent with the shape of the reflection peak in the reference reflection peak information, if the difference between the first width and the second width is greater than the target threshold, it is determined that the port to be detected is connected to the optical terminal device; if the difference between the first width and the second width is not greater than the target threshold, it is determined that the port to be detected is not connected to the optical terminal device. The first width is the width of the reflection peak at the first position in the first reflection peak information, and the second width is the width of the reflection peak at the first position in the reference reflection peak information.

[0046] When the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information, it is determined that the port to be detected is not connected to the optical terminal equipment.

[0047] Fifthly, this disclosure provides a system for detecting port status, the system comprising an optical line terminal, a combiner / splitter, an optical distribution network, an optical terminal device, and a detection device for the presence of pulsed test light as described in the first aspect, or a device as described in the second aspect and any of the alternative embodiments of the second aspect; the optical line terminal is connected to the combiner / splitter, the device is connected to the combiner / splitter; the combiner / splitter is connected to the optical distribution network; and the optical distribution network is connected to the optical terminal device. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a PON system provided in an exemplary embodiment of this disclosure;

[0049] Figure 2 This is a schematic diagram of a two-level PON system provided in an exemplary embodiment of this disclosure;

[0050] Figure 3 This is a schematic diagram illustrating the use of a detection device provided in an exemplary embodiment of this disclosure;

[0051] Figure 4 This is a schematic diagram illustrating the use of the detection device provided in another exemplary embodiment of this disclosure;

[0052] Figure 5This is a schematic diagram of a detection system for detecting port status provided in an exemplary embodiment of this disclosure;

[0053] Figure 6 This is a schematic diagram of an ONT provided in an exemplary embodiment of this disclosure;

[0054] Figure 7 This is a schematic diagram of the structure of a detection device provided in another exemplary embodiment of this disclosure;

[0055] Figure 8 This is a schematic diagram of a process for detecting port status provided in an exemplary embodiment of this disclosure;

[0056] Figure 9 This is a schematic diagram of optical time-domain reflectometer (OTDR) test curves under pulse detection light of different polarization states provided in an exemplary embodiment of this disclosure;

[0057] Figure 10 This is a schematic diagram of a process for detecting port status provided in another exemplary embodiment of this disclosure;

[0058] Figure 11 This is a schematic diagram of the connection between the ONT and the drop cable provided in another exemplary embodiment of this disclosure;

[0059] Figure 12 This is a schematic diagram of the reflection peaks of a connected ONT and an unconnected ONT provided in another exemplary embodiment of this disclosure;

[0060] Figure 13 This is a schematic diagram illustrating the detection of the detection port status provided in another exemplary embodiment of this disclosure;

[0061] Figure 14 This is a schematic diagram of a process for detecting port status provided in another exemplary embodiment of the present disclosure.

[0062] Illustration

[0063] 1. Polarization light generation module; 2. Beam combiner / splitter; 3. Detector; 4. Pulse light generation module;

[0064] 11. Test light generator; 12. Light polarization controller. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0066] In point-to-point or multipoint systems, it is typically necessary to detect whether an optical terminal equipment (OPE) is connected to the end of the fiber optic cable at the port. For example, in access networks, PON has experienced rapid development and large-scale deployment over the past decade due to its advantages in technology and cost. A PON system is a point-to-multipoint system, consisting of an OLT, ODN, and ONU or ONT connected sequentially. See [link to documentation]. Figure 1 In an optical network (ODN), the Optical Line Transmission (OLT) is used to connect to one or more of the Public Switched Telephone Network (PSTN), the Internet, or the Community Antenna Television (CATV). The Optical Distribution Network (ODN) is a passive optical device, primarily consisting of three optical fiber segments and a splitter. The three segments are the backbone fiber, the distribution fiber (in the case of secondary splitting), and the branch fiber. The branch fiber is also known as the drop cable or drop fiber. Each fiber segment is connected via the splitter. ODN transmits optical signals from the central office to multiple users through a point-to-multipoint connection method. It is characterized by wide geographical coverage, a large number of branch optical paths, and complex scenarios. Furthermore, since it lacks its own power supply, operators face problems such as high maintenance costs, slow service activation, and inaccurate resource management data during the actual construction, commissioning, and operation of ODN. Specifically, when a user no longer leases a network from an operator, they only need to return the optical modem (ONT) at home. The other end of the fiber optic cable connecting to the operator's home is still connected to a port on the splitter. This causes the operator to be unable to distinguish which ports are available when activating internet service for new users, mistakenly assuming all ports are occupied and requiring additional equipment to meet the new user's internet needs. Therefore, a method is needed to identify the port status of the splitter, that is, to identify which ports' fiber optic cable ends are not actually connected to the ONT. This would allow the connection to the unconnected ports to be disconnected, freeing up available ports.

[0067] Based on this, the present disclosure provides a scheme for detecting port status. In this scheme, test light of multiple polarization states is sent to the optical fiber connected to the port to be tested. If the end of the optical fiber connected to the port to be tested is connected to an optical terminal device, the power of the optical transceiver components inside the optical terminal device reflecting the test light of different polarization states will have a large difference. Whether there is a large difference can be used to determine whether the end of the optical fiber is connected to an optical terminal device.

[0068] This disclosure provides an apparatus for detecting port status. For ease of description, this apparatus will be referred to hereafter as a detection device. This detection device is applied in fiber optic transmission systems such as point-to-multipoint systems or point-to-point systems, where the optical terminal equipment connected to the end of the optical fiber has a significant difference in reflectivity for light of different polarization states at a specific wavelength. Point-to-multipoint systems include, but are not limited to, PON systems. For example, this detection device is used to identify whether an ONT is connected to the end of the drop cable in an ODN. See [link to relevant documentation]. Figure 2 The PON system shown includes an ODN comprising two-stage optical splitters (a primary splitter and a secondary splitter). Drop optical cables 1 and 3 are connected to an ONT, while drop optical cable 2 is not connected to an ONT. In this embodiment, the ODN can be either equally or unequally split. Figure 2 This explanation uses a two-stage optical splitter as an example. However, there can also be only a single-stage splitter, or no splitter at all. This is equivalent to the ONT and OLT being directly connected via fiber optic cable. As long as the ONT is connected to the ODN network via fiber optic cable, there are no special requirements regarding the form of the ODN network. A point-to-point system is any system that uses direct fiber optic connections. For example, in a point-to-point system, one OLT and one ONT are directly connected, or switches are directly connected via inserted optical modules, or routers are directly connected via inserted optical modules.

[0069] The following text will use the application of the detection device in a PON system as an example for explanation.

[0070] The testing device has two usage modes when in the testing port state. The first mode is as follows: The testing device can be used as a testing instrument. At the splitter location, disconnect the incoming optical cable connected to the ONT from the splitter and plug it into the testing device's optical port. In this way, the testing device is directly connected to the incoming optical cable. (See [link]). Figure 3 The diagram shown illustrates how to use the product. Figure 3 The detection device is used to detect whether the optical cable connected to ONT1 is connected to an ONT. When it is used to detect whether the optical cable connected to ONT2 is connected to an ONT, the optical cable connected to ONT2 is unplugged from the splitter and plugged into the optical port of the detection device.

[0071] The second usage method is as follows: This detection device can also be deployed as a detection equipment in the central office equipment room. It combines the test light and service light into a single beam using a combiner / splitter, and transmits it through the optical fiber until it reaches the end ONT. By sending pulsed test light, it determines whether the ONT is connected to the end of the drop cable. In this way, the detection device and the drop cable are indirectly connected via ODN. See [link to ODN documentation]. Figure 4 The diagram shown illustrates how to use the product. Figure 4 The image shows two ONTs. The detection device is used to detect whether the optical fiber cable connecting the two ONTs is connected to an ONT.

[0072] It should be noted that when using the second method, since the test light can be transmitted to each end of the drop cable in the ODN, the detection device can simultaneously detect whether each end of the drop cable is connected to an ONT. However, it is necessary to ensure that there are no two drop cable ends that are equidistant from the detection device.

[0073] Figure 5 A schematic diagram of a detection system is provided. The system includes a detection device and a drop cable, or the system includes the detection device, the drop cable, and an ONT (On-Premises Terminal) connected to the end of the drop cable. The drop cable is connected to the ONT using a fiber optic connector, which is either an Ultra Physical Contact (UPC) connector or an Angled Physical Contact (APC) connector. Figure 5 The example shown is when an ONT is connected to the end of the drop cable. The detection device sends test light signals of various polarization states to the drop cable, receives the reflected light, and determines the detection information of the reflected light. This detection information is used to determine the status of the port connected to the drop cable.

[0074] See Figure 5The detection device is directly or indirectly connected to the drop cable connected to the port to be tested, which is the port of the splitter in the ODN. The detection device includes a polarization light generation module 1, a beam combiner / splitter 2, and a detector 3. The polarization light generation module 1 is connected to the beam combiner / splitter 2 via optical fiber, and the beam combiner / splitter 2 is connected to the detector 3 via optical fiber. The beam combiner / splitter 2 is also used to connect to the drop cable connected to the port to be tested. The polarization light generation module 1 generates test lights with multiple polarization states one by one. Each time a test light with a different polarization state is generated, it is output to the beam combiner / splitter 2. The power and wavelength of the test lights with multiple polarization states are the same, and the wavelength is the same as or similar to the wavelength of the uplink optical signal. The uplink optical signal is the optical signal sent by the optical terminal equipment connected to the port to be tested. It can also be understood that the wavelength difference between the two is less than the wavelength difference threshold. The wavelength difference threshold is relatively small, and the principle is to determine the difference in the reflected light of the test lights with different polarization states. When the detection device is directly connected to the drop cable, the wavelength of the test lights with multiple polarization states is the same as or similar to the wavelength of the uplink optical signal. When the detection device is indirectly connected to the drop cable through the ODN, the wavelength of the test lights with multiple polarization states is similar to the wavelength of the uplink optical signal. In this way, the reflected test light will return to the detection device and will not enter the OLT. After receiving test light of each polarization state, the beam combiner / splitter 2 sends the received test light to the connected drop cable. The drop cable transmits the input test light. When an ONT is connected to the end of the drop cable, the ONT reflects the received test light, causing the reflected light to propagate through the drop cable. The drop cable then transmits the reflected light to the beam combiner / splitter 2. When no ONT is connected to the end of the drop cable, the end of the drop cable reflects the input test light, resulting in reflected light, which is then transmitted to the beam combiner / splitter 2. The beam combiner / splitter 2 then inputs the received reflected light to the detector 3. The detector 3 detects the received reflected light, obtaining reflected light detection information corresponding to each polarization state of the test light. This reflected light detection information is used to determine the state of the port to be tested, i.e., whether the port to be tested is connected to an ONT.

[0075] The principle for determining the status of the port to be detected based on this detection information is as follows:

[0076] Figure 6 The internal structure of the optical transmitter-receiver integrated assembly within the ONT is provided. This assembly is a bi-directional optical sub-assembly (BOSA), which includes a 45-degree filter, a laser, and a photodetector. The 45-degree filter directs optical signals of different wavelengths in different directions. Figure 6In the diagram, solid black lines represent light with wavelengths greater than A, and dashed black lines represent light with wavelengths less than A, such as A being 1360 nm. Light with wavelengths greater than A is reflected by a 45-degree filter and transmitted downwards into the photodetector. Light with wavelengths less than A is transmitted through the 45-degree filter and into the laser. The laser consists of a gain medium and a resonant cavity. The resonant cavity, located between an anti-reflection coating (ARcoating) and a high-reflection coating (HRcoating), provides wavelength selection and polarization mode selection. Only light of a specific wavelength and polarization mode can propagate within the laser without attenuation. This specific wavelength is the same as or close to the wavelength of the laser output from the BOSA within the OLT. The photodetector receives the downlink optical signal transmitted by the OLT. When an ONT is connected to the end of the drop cable, the test light enters the ONT through the drop cable, passes through the ONT's fiber optic connector, and then enters the BOSA. After entering the BOSA, the test light passes through a 45-degree filter. The 45-degree filter transmits the test light to the laser, which reflects the test light and outputs it to the drop cable, thereby transmitting it to detector 3.

[0077] If the test light meets the specific wavelength and polarization mode, it first enters the laser through the AR coating, then reflects back after reaching the HR coating (approximately 90% of the light), re-enters the drop cable, and finally reaches the detection device. If the test light meets the specific wavelength but not the specific polarization mode, most of the test light is attenuated after entering the laser through the AR coating. A small portion is attenuated again after reflecting back after reaching the HR coating, and finally only a small amount of light (approximately 10% of the light) can re-enter the drop cable and reach the detection device.

[0078] In this way, if the end of the drop cable is not connected to the ONT, is a suspended fiber connector, or is broken, the amount of reflected light is irrelevant to the polarization state of the test light. Therefore, the amount of reflected light can be used to determine whether the end of the drop cable is connected to the ONT.

[0079] It should be noted that, Figure 6 This is a schematic diagram of one possible structure for a bidirectional optical module; other bidirectional optical modules may have different structures. Figure 6 For example, there may be multiple waveplates, multiple reflections, and multiple transmissions, but the detection principle of the embodiments of this disclosure can be applied to these different structures.

[0080] In one alternative approach, the test light generation and polarization state control can be integrated into the detection device; that is, the polarization light generation module 1 is an integrated module. Alternatively, the test light can be generated first, and then the polarization state can be changed. In this case, the polarization light generation module 1 in the detection device includes a test light generator 11 and a light polarization controller 12. (See [reference]) Figure 7 The test light generator 11 can be a laser, used to generate a first test light and send it to the optical polarization controller 12. When the test light is DC light, the test light generator 11 is a DC light generator; when the test light is pulsed light, the test light generator 11 is a pulsed light generator. The optical polarization controller 12 adjusts the polarization state of the first test light sequentially to output test light with multiple polarization states sequentially. Here, after obtaining detection information using the test light with the i-th polarization state, the system switches to the test light with the (i+1)-th polarization state to prevent adjacent polarization states from interfering with each other. For example, the optical polarization controller 12 switches polarization states at a preset interval, which is the minimum interval that prevents adjacent polarization states from interfering with each other.

[0081] Optionally, when the test light is pulsed light, the test light generator 11 includes pulse generation, driving and control parts.

[0082] Optionally, the optical combiner / splitter 2 can be an optical coupler or an optical circulator.

[0083] Optionally, when the test light is DC light, detector 3 is used to measure the power of the reflected light, as well as to record, analyze, and store the measured power of the reflected light. When the test light is pulsed light, detector 3 is used to receive the reflected or scattered light, and also includes a processing and control section for calculating, analyzing, and storing the OTDR curve of the reflected or scattered light.

[0084] In one optional method, the test light is DC light. The drop cable connected to the port to be tested is unplugged from the splitter and plugged into the optical port of the testing device, i.e., the drop cable is plugged into the testing device. The polarization light generation module 1 generates DC test light of multiple polarization states one by one. Each time a DC test light of a different polarization state is generated, it is output to the combiner / splitter 2. The DC test light of multiple polarization states has the same power and wavelength, and the wavelength is the same as or similar to the wavelength of the uplink optical signal, which is the uplink optical signal of the ONT connected to the drop cable. After receiving DC test light of each polarization state, the beam combiner / splitter 2 sends the received DC test light to the connected drop cable. When an ONT is connected to the end of the drop cable, the ONT reflects the received DC test light, causing the reflected light to propagate through the drop cable and reach the beam combiner / splitter 2. When no ONT is connected to the end of the drop cable, the end of the drop cable reflects the input DC test light, resulting in reflected light, which is then transmitted to the beam combiner / splitter 2. The beam combiner / splitter 2 then inputs the received DC test light to the detector 3. The detector 3 converts the reflected light into an electrical signal, determines the power of the reflected light, obtains the power of the reflected light under each polarization state, determines the maximum and minimum power among these powers, and calculates the difference between the maximum and minimum power, which is called the first difference. Detector 3 determines the relationship between the first difference and the first threshold. If the first difference is greater than the first threshold, it indicates a significant change in the reflected optical power of the test light from different polarization states, confirming that an ONT is connected to the end of the drop cable, i.e., the port to be tested is connected to an ONT. If the first difference is not greater than the first threshold, it indicates no significant change in the reflected optical power of the test light from different polarization states, confirming that an ONT is not connected to the end of the drop cable, i.e., the port to be tested is not connected to an ONT. Here, the first threshold is set based on the results of multiple simulation tests. For example, when there is no ONT connected to the end of the drop cable, the difference in reflected power of the test light from different polarization states is very small, usually less than 1 dB, so the first threshold can be set to 2 dB.

[0085] Figure 8 A flowchart for the detection process when the test light is DC light is provided. See [link / reference] Figure 8 Step 801, test begins.

[0086] Step 802: The polarization light generation module 1 sends out DC test light with polarization states X1 to Xn one by one through the beam combiner / splitter 2.

[0087] Step 803: Detector 3 acquires the reflected light power Y1 to Yn corresponding to the DC test light of polarization states X1 to Xn, respectively.

[0088] Step 804: The polarization light generation module 1 determines whether the test of n polarization states has been completed. If the test of n polarization states has not been completed, proceed to step 802. If the test of n polarization states has been completed, obtain the maximum power and minimum power among Y1 to Yn, and proceed to step 805.

[0089] Step 805, detector 3 obtains the first difference between the maximum power and the minimum power, that is, the first difference is equal to max(Y1~Yn)-min(Y1~Yn).

[0090] Step 806: Detector 3 determines whether the first difference is greater than the first threshold. If it is greater, it is determined that an ONT is connected to the end of the optical cable to the home. If it is not greater, it is determined that an ONT is not connected to the end of the optical cable to the home.

[0091] For example, Table 1 provides the test results for a gigabit-capable PON (GPON). By sending test light of the wavelength of the laser in the ONT (i.e., 1310nm test light) to the ONT in the GPON, it can be seen that the reflected light power of the test light under different polarization states differs by 8.9dB. Table 1 provides the test light for seven polarization states, and also provides the reflected light power differences of test light of the wavelength of the laser in non-ONT locations.

[0092] Table 1

[0093]

[0094] Table 2 provides the test results for a 10 gigabit-capable PON (XGPON). By sending test light of the wavelength of the laser in the ONT (i.e., 1270nm test light) to the ONT in the XGPON, it can be seen that the reflected light power of the test light under different polarization states differs by 5.9dB. Table 2 provides the test light for seven polarization states, and also provides the reflected light power differences of test light of the wavelength of the laser outside the ONT.

[0095] Table 2

[0096]

[0097] In another alternative approach, the test light is pulsed light. The drop cable connected to the port to be tested is unplugged from the splitter and plugged into the optical port of the testing device, thus connecting the drop cable to the testing device. Alternatively, the testing device can be located in the central office equipment room, with both the testing device and the OLT connected to a combiner / splitter, which in turn is connected to the ODN. This effectively connects the testing device and the drop cable indirectly through the splitter in the ODN.

[0098] When the test light is pulsed light, the polarization light generation module 1 generates pulsed test light of multiple polarization states one by one. Each time a pulsed test light of a different polarization state is generated, it is output to the beam combiner / splitter 2. When the detection device is directly connected to the drop cable, the power and wavelength of the pulsed test light of multiple polarization states are the same, and the wavelength is the same as or similar to the wavelength of the uplink optical signal. The uplink optical signal is the uplink optical signal of the ONT connected to the drop cable. When the detection device is indirectly connected to the drop cable through the ODN, the power and wavelength of the pulsed test light of multiple polarization states are the same, and the wavelength is similar to the wavelength of the uplink optical signal. The uplink optical signal is the uplink optical signal of the ONT connected to the drop cable. After receiving pulsed test light of each polarization state, the beam combiner / splitter 2 sends the received pulsed test light to the connected drop cable. When an ONT is connected to the end of the drop cable, the ONT reflects the received pulsed test light, causing the reflected light to propagate through the drop cable and reach beam combiner / splitter 2. When no ONT is connected to the end of the drop cable, the end of the drop cable reflects the input pulsed test light, resulting in reflected light, which is then transmitted to beam combiner / splitter 2. Beam combiner / splitter 2 then inputs the received reflected light to detector 3. For each polarization state of the pulsed test light, detector 3 converts the reflected light into an electrical signal, determines the power and time of the reflected light, and generates an OTDR curve corresponding to that polarization state. The horizontal axis of the OTDR curve represents distance, and the vertical axis represents the power of the scattered / reflected light. Detector 3 acquires the distance between the end of the drop cable and the detection device. In the OTDR curve corresponding to each polarization state, it obtains the height of the reflection peak at that distance (i.e., the optical power of the scattered / reflected light at that distance), determining the maximum and minimum reflection peak heights for the test light corresponding to various polarization states. Detector 3 calculates a second difference between the maximum and minimum reflection peak heights and determines the relationship between this second difference and a second threshold. If the second difference is greater than the second threshold, it indicates a significant change in the optical power reflected from the test light of different polarization states, confirming that the drop cable is connected to the optical terminal equipment (ONT), i.e., the port to be tested is connected to the ONT. If the second difference is not greater than the second threshold, it indicates no significant change in the optical power reflected from the test light of different polarization states, confirming that the drop cable is not connected to the optical terminal equipment (ONT), i.e., the port to be tested is not connected to the ONT. Here, the second threshold is set based on the results of multiple simulation tests; for example, the second threshold is 3dB. Figure 9 A schematic diagram of the OTDR curve is provided. The reflection peak of the solid black line is the reflection peak when the polarization state of the pulsed test light and the laser in the ONT is the same, and the reflection peak of the dashed black line is the reflection peak when the polarization state of the pulsed test light and the laser in the ONT is not the same. It can be seen that the height difference between the two is greater than 5dB, which confirms that the end of the optical cable to the home is connected to the ONT.

[0099] It should be noted that when generating the OTDR curve for each polarization state, the pulsed test light for that polarization state can be sent multiple times to obtain multiple sets of data. These multiple sets of data are then averaged to generate the OTDR curve for that polarization state. Furthermore, the above explanation uses the generation of an OTDR curve as an example; alternatively, the height of the reflection peak at the end of the drop cable can be directly read from the data acquired by detector 3 without generating an OTDR curve.

[0100] It should also be noted that when using DC test light, strong reflection occurs at any intermediate point before the test light reaches the end of the optical cable. Since the reflectivity of the reflecting surface is related to the wavelength and polarization state, the reflected light at that intermediate point will be superimposed with the light power reflected at the end of the optical cable, affecting the determination of whether the end of the optical cable is connected to an ONT. However, when using pulsed light, the reflection of the reflected light at different points is measured independently, so the detection results are accurate.

[0101] Figure 10 A flowchart for detection when the test light is pulsed light is provided. See also... Figure 10 Step 1001, test begins.

[0102] Step 1002: The polarization light generation module 1 sends out pulse test light with polarization states X1 to Xm one by one through the beam combiner / splitter 2, where m and n may be the same or different.

[0103] Step 1003: Detector 3 acquires the reflection peak heights Z1 to Zm corresponding to the polarization states X1 to Xm at the end of the optical cable.

[0104] Step 1004: The polarization light generation module 1 determines whether the test of m polarization states has been completed. If the test of m polarization states has not been completed, proceed to step 1002. If the test of m polarization states has been completed, obtain the maximum reflection peak height and minimum reflection peak height among Z1 to Zm, and proceed to step 1005.

[0105] Step 1005: Detector 3 obtains the second difference between the maximum reflection peak height and the minimum reflection peak height, that is, the second difference is equal to max(Z1~Zm)-min(Z1~Zm).

[0106] Step 1006: Detector 3 determines whether the second difference is greater than the second threshold. If it is greater, it is determined that an ONT is connected to the end of the optical cable to the home. If it is not greater, it is determined that an ONT is not connected to the end of the optical cable to the home.

[0107] Optionally, when the test light is pulsed light, the detection device can be an OTDR with adjustable polarization state, that is, adding a light polarization controller to the original OTDR.

[0108] In one alternative approach, detector 3 has a calculation function. After obtaining the reflected light detection information corresponding to the test light of each polarization state, it determines whether the port to be tested is connected to an ONT based on the reflected light detection information.

[0109] In another alternative approach, the detection device also includes a controller. The detector 3 does not have a calculation function. After obtaining the reflected light detection information corresponding to the test light of each polarization state, it sends the reflected light detection information to the controller. The controller determines the state of the port to be detected based on the reflected light detection information. The determination process is described above and will not be repeated here.

[0110] This disclosure also provides another device for detecting port status, which, for ease of description, is also referred to as a detection device. This detection device is used to detect port status in a PON system. The detection device is connected to the drop optical cable connected to the port to be detected. The drop optical cable connected to the port to be detected is unplugged from the splitter and plugged into the optical port of the detection device; that is, the drop optical cable is plugged into the detection device. See [link to relevant documentation]. Figure 3 Alternatively, the detection device can be located in the central office equipment room. Both the detection device and the OLT are connected to a combiner / splitter, which in turn is connected to the ODN. This is equivalent to the detection device and the drop cable being indirectly connected through the splitter in the ODN. (See [link to relevant documentation]). Figure 4 The detection principle of this detection device is as follows:

[0111] See Figure 11 and Figure 12 When the ONT is connected to the drop cable, it is connected via a fiber optic connector. Assuming the drop cable ends with an ONT, when the pulsed test light is transmitted to the ONT's optical inlet, the fiber optic connector at that inlet will generate the first reflection. The remaining pulsed test light then travels through the fiber optic cable to the BOSA (Optical Optimal Receiver Array), where it will generate a second reflection at the 0-degree waveplate or lens in front of the receiver, or at other locations. The distance between these two reflection points is typically 10cm to 50cm. When the pulse width of the pulsed test light is relatively small, the detection device can distinguish the broadening of the ONT's own reflection peak caused by two consecutive reflecting surfaces. These two reflecting surfaces include the reflecting surface at the fiber optic connector at the optical inlet and the reflecting surface generated by the BOSA. This broadening refers to a wider reflection peak compared to a single reflecting surface. Figure 12As shown, the solid black line reflection peaks are caused by the UPC connector of the drop cable not being connected to the ONT or by a broken fiber (i.e., caused by a single reflective surface), while the dashed black line reflection peaks are caused by the drop cable being connected to the ONT (i.e., caused by two reflective surfaces). It is clearly visible that the width of the dashed black line reflection peak at the first position is greater than the width of the solid black line reflection peak at the first position, indicating that the dashed black line reflection peak represents the case where the drop cable is connected to the ONT. The first position is the position X dB downwards from the top of the reflection peak. The value of X should be set according to actual needs, but should not be set too large, as an excessively large value will easily be drowned out by noise.

[0112] See Figure 13 In the detection device, the pulse light generation module 4 generates a pulsed test light and outputs it to the beam combiner / splitter 2. The wavelength of this pulsed test light is typically selected within the band of high BOSA reflectivity in the ONT, i.e., reflectivity higher than a reflectivity threshold. This reflectivity threshold is determined with the goal of revealing the second reflecting surface. Specifically, if using... Figure 3 The connection method shown and Figure 4 In the connection method shown, this wavelength can be the reflected light band of the 45-degree filter, excluding the wavelength of the BOSA detector, so as not to affect the optical signal reception of the BOSA. In this way, the second reflection is located at the 0-degree filter in the receiving section. The 0-degree filter transmits the light that the ONT needs to receive to the detector, while filtering out light that the ONT does not need to receive. Alternatively, this wavelength can be the transmitted light of the 45-degree filter. Figure 3 The method shown may include the wavelength of the uplink optical signal transmitted by BOSA, while Figure 4The connection method shown does not include the wavelength of the uplink optical signal sent by the BOSA. This is because if the same wavelength were used, this part of the light would return to the OLT, affecting the OLT. Thus, the second reflection is located in the transmission section. The pulse test light is a narrow pulse signal with high OTDR event resolution, meaning it can easily distinguish closely adjacent reflection events in the fiber optic link. The pulse width is less than or equal to the target value, which can be 3ns. In this case, the pulse light generation module 4 can also be called a narrow pulse light generator. After receiving the pulse test light, the combiner / splitter 2 sends the received pulse test light to the connected drop cable. The drop cable transmits the input pulse test light. When an ONT is connected at the end of the drop cable, the ONT connector and the BOSA reflect the received pulse test light, causing the reflected light to propagate in the drop cable. The drop cable transmits the reflected light to the combiner / splitter 2. When no ONT is connected at the end of the drop cable, the connector at the end of the drop cable reflects the input pulse test light, resulting in reflected light, which the drop cable then transmits to the combiner / splitter 2. The beam combiner / splitter 2 inputs the received reflected light to the detector 3. The detector 3 converts the reflected light into an electrical signal, determines the power of the reflected light and the reception time, and generates an OTDR curve. The horizontal axis of the OTDR curve represents distance, and the vertical axis represents the power of the scattered or reflected light. The detector 3 obtains the distance between the end of the drop cable and the detection device. In the OTDR curve corresponding to each polarization state, it obtains the reflection peak information at that distance, i.e., the first reflection peak information. The detector 3 uses the first reflection peak information to determine whether an ONT is connected to the end of the drop cable.

[0113] In one alternative approach, detector 3 acquires the width of the first position in the first reflection peak information, and determines the size of the width of the first position relative to a third threshold. If the width of the first position is greater than the third threshold, it is determined that an ONT is connected to the end of the optical cable to the home. If the width of the first position is not greater than the third threshold, it is determined that an ONT is not connected to the end of the optical cable to the home.

[0114] In another alternative approach, because the pulse shape of the pulsed test light emitted by some detection devices may be distorted or broadened, the reflection peak generated when encountering a single reflecting surface will also be distorted or broadened. Figure 12 The reflection peak of the solid black line in the middle is distorted; it is not a symmetrical Gaussian pulse shape, but rather broadens on the right. Therefore, comparing it solely based on the width of the reflection peak can easily lead to misjudgment. Thus, standard reflection peak information can be obtained in advance as a reference, and processed as follows:

[0115] Detector 3 acquires stored reference reflection peak information, which is either the pulse information of the pulsed test light or the reflection peak information generated by the pulsed test light on a single reflecting surface. The reference reflection peak information includes the shape of the reflection peak and the width at a first position. Based on the first reflection peak information and the reference reflection peak information, detector 3 determines the state of the port to be detected.

[0116] Optionally, the process of determining the state of the port to be detected based on the first reflection peak information and the reference reflection peak information is as follows:

[0117] Detector 3 determines whether the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information. If the two reflection peak shapes are inconsistent, the width of the reflection peak at the first position in the first reflection peak information is obtained, called the first width, and the width of the reflection peak at the first position in the reference reflection peak information is obtained, called the second width. The difference between the first width and the second width is calculated. The relationship between this difference and the target threshold is determined. If the difference is greater than the target threshold, it is determined that the drop cable is connected to the ONT, that is, the port to be detected is connected to the ONT. If the difference is not greater than the target threshold, it is determined that the drop cable is not connected to the ONT, that is, the port to be detected is not connected to the ONT. If the two reflection peak shapes are consistent, it means that there is only one reflecting surface, then the end of the drop cable is not connected to the ONT, that is, the port to be detected is not connected to the ONT. Here, the target threshold can be obtained from simulation.

[0118] The process for determining whether the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information is as follows:

[0119] After aligning the height of the reflection peak in the first reflection peak information with the height of the reflection peak in the reference reflection peak information, it is determined whether the width difference at each position from the top to the second position is less than a fourth threshold. If it is less than the fourth threshold, the shapes are determined to be consistent; otherwise, the shapes are determined to be inconsistent. The fourth threshold can be set according to actual needs.

[0120] It should be noted that the first position can be a single location point or multiple location points. For example, the first position includes every location point from the top to the first position.

[0121] It should also be noted that when generating the OTDR curve, the pulse test light can be sent multiple times to obtain multiple sets of data. The OTDR curve is then generated by averaging these multiple sets of data. Furthermore, the above explanation uses the generation of an OTDR curve as an example. Alternatively, the reflection peak information at the end of the drop cable can be directly read from the data without generating an OTDR curve.

[0122] Figure 14 A flowchart for detection when the test light is pulsed light is provided. See also... Figure 14Step 1401, test begins.

[0123] Step 1402: The pulse light generation module 4 sends out pulse test light through the beam combiner / splitter 2.

[0124] Step 1403: Detector 3 acquires the first reflection peak information at the end of the optical cable and determines whether the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information. If they are inconsistent, proceed to step 1404; if they are consistent, proceed to step 1406.

[0125] Step 1404: Detector 3 determines whether the difference between the first width and the second width is greater than the target threshold. If it is greater than the target threshold, proceed to step 1405. If it is not greater than the target threshold, proceed to step 1406.

[0126] Step 1405: Detector 3 confirms that an ONT is connected to the end of the incoming optical cable.

[0127] Step 1406: Detector 3 determines that no ONT is connected to the end of the incoming optical cable.

[0128] In this embodiment of the disclosure, through the above-mentioned detection schemes, the detection device can identify the port of the splitter that is not connected to the ONT using only one laser, thus solving the problem of the splitter being removed from the ODN without disconnecting the cable and thus occupying the port.

[0129] This disclosure also provides another scheme for detecting port status, which... Figure 5 and Figure 13 By combining the two methods, if the detection results of the two methods are different for a certain port, the detection device can be replaced and the detection can be repeated. If the detection results of the two methods are the same, the detection result is determined to be accurate.

[0130] This disclosure also provides a method for detecting ports, which is applied to point-to-point or multi-point systems. The method includes the following steps:

[0131] Test light of multiple polarization states is generated and sent to the optical fiber connected to the port to be tested. The test light of multiple polarization states has the same power and wavelength, and the wavelength difference with the uplink optical signal is less than the wavelength difference threshold. The uplink optical signal is the optical signal sent by the optical terminal equipment connected to the optical fiber.

[0132] The reflected light transmitted through the optical fiber is received, and the reflected light is detected to obtain the reflected light detection information corresponding to the test light of each polarization state.

[0133] The state of the port to be tested is determined based on the reflected light detection information corresponding to the test light of each polarization state.

[0134] In one alternative approach, the generation and transmission of test light in multiple polarization states to the optical fiber connected to the port to be tested, one by one, includes:

[0135] Generate the first test light;

[0136] The polarization state of the first test light is adjusted one by one to output test light with the various polarization states one by one.

[0137] In one alternative approach, the test light is direct current light;

[0138] The step of detecting the reflected light to obtain the reflected light detection information corresponding to each polarization state of the test light includes:

[0139] The power of the reflected light is detected to obtain the power of the reflected light corresponding to each polarization state of the test light;

[0140] The determination of the state of the port to be tested based on the reflected light detection information corresponding to the test light of each polarization state includes:

[0141] Determine the first difference between the maximum and minimum power of the reflected light corresponding to the test light in the various polarization states;

[0142] If the first difference is greater than the first threshold, then it is determined that the port to be detected is connected to the optical terminal device;

[0143] If the first difference is not greater than the first threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

[0144] In one alternative approach, the test light is pulsed light;

[0145] The step of detecting the reflected light to obtain the reflected light detection information corresponding to each polarization state of the test light includes:

[0146] The reflected light at the end of the optical fiber is detected to obtain the reflection peak height of the reflected light corresponding to each polarization state of the test light at the end of the optical fiber.

[0147] The determination of the state of the port to be tested based on the reflected light detection information corresponding to the test light of each polarization state includes:

[0148] Determine the second difference between the maximum and minimum reflection peak heights of the reflected light corresponding to the test light in the various polarization states;

[0149] If the second difference is greater than the second threshold, then it is determined that the port to be detected is connected to the optical terminal device;

[0150] If the second difference is not greater than the second threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

[0151] This disclosure also provides another method for detecting port status, which is applied to point-to-point or multipoint systems. The method includes the following steps:

[0152] A pulsed test light is generated and sent to the optical fiber connected to the port to be tested. The wavelength of the pulsed test light is greater than the reflectivity threshold of the bidirectional optical component, and the pulse width is less than or equal to the target value. The bidirectional optical component belongs to the optical terminal device connected to the port to be tested via the optical fiber.

[0153] Receive the reflected light transmitted through the optical fiber and determine the first reflection peak information of the reflected light corresponding to the pulse test light at the end of the optical fiber;

[0154] Based on the first reflection peak information, the state of the port to be detected is determined.

[0155] In one alternative approach, determining the state of the port to be detected based on the first reflection peak information includes:

[0156] Based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light, the state of the port to be tested is determined. The reference reflection peak information is the pulse information of the pulsed test light or the reflection peak information generated by the pulsed test light on a single reflective surface.

[0157] In one optional approach, determining the state of the port to be tested based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light includes:

[0158] When the shape of the reflection peak in the first reflection peak information is inconsistent with the shape of the reflection peak in the reference reflection peak information, if the difference between the first width and the second width is greater than the target threshold, it is determined that the port to be detected is connected to the optical terminal device; if the difference between the first width and the second width is not greater than the target threshold, it is determined that the port to be detected is not connected to the optical terminal device. The first width is the width of the reflection peak at the first position in the first reflection peak information, and the second width is the width of the reflection peak at the first position in the reference reflection peak information.

[0159] When the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information, it is determined that the port to be detected is not connected to the optical terminal device.

[0160] The above method and process have been explained in the previous text, and will not be repeated here.

[0161] In this disclosure, the terms "first" and "second," etc., are used to distinguish identical or similar items that have substantially the same function and purpose. It should be understood that there is no logical or temporal dependency between "first" and "second," nor does it limit the quantity or order of execution. It should also be understood that although the following description uses the terms "first" and "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another. For example, without departing from the scope of various examples, a first width can be referred to as a second width, and similarly, a second width can be referred to as a first width. Both the first width and the second width can be widths, and in some cases, they can be separate and different widths.

[0162] The above description is merely an exemplary embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this disclosure, and such modifications or substitutions should all be covered within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A device for detecting port status, characterized in that, The device is applied to point-to-point or multi-point systems, and the device includes a polarization light generation module (1), a beam combiner / splitter (2), and a detector (3); The polarization light generation module (1) is used to generate and output test light of multiple polarization states to the beam combiner (2) one by one. The power and wavelength of the test light of multiple polarization states are the same, and the wavelength difference with the uplink optical signal is less than the wavelength difference threshold. The uplink optical signal is the optical signal sent by the optical terminal device connected to the port to be tested through the optical fiber. The beam combiner (2) is used to connect to the optical fiber, send the received test light to the optical fiber, and receive and output the reflected light transmitted by the optical fiber to the detector (3); The detector (3) is used to detect the received reflected light and obtain the reflected light detection information corresponding to the test light of each polarization state. The reflected light detection information corresponding to the test light of each polarization state is used to determine the state of the port to be detected.

2. The apparatus according to claim 1, characterized in that, The polarization light generation module (1) includes a test light generator (11) and a light polarization controller (12); The test light generator (11) is used to generate a first test light and send the first test light to the optical polarization controller (12); The optical polarization controller (12) is used to adjust the polarization state of the first test light one by one, so as to output the test light with the multiple polarization states one by one.

3. The apparatus according to claim 1 or 2, characterized in that, The test light is DC light, and the optical fiber is plugged into the device; The detector (3) is used to detect the power of the received reflected light and obtain the power of the reflected light corresponding to each polarization state of the test light; Determine the first difference between the maximum and minimum power of the reflected light corresponding to the test light in the various polarization states; If the first difference is greater than the first threshold, then it is determined that the port to be detected is connected to the optical terminal device; If the first difference is not greater than the first threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

4. The apparatus according to claim 1 or 2, characterized in that, The test light is pulsed light, and the device is plugged into the optical fiber or connected to a splitter in an optical distribution network. The detector (3) is used to detect the reflected light at the end of the optical fiber and obtain the reflection peak height of the reflected light corresponding to each polarization state of the test light at the end of the optical fiber. Determine the second difference between the maximum and minimum reflection peak heights of the reflected light corresponding to the test light in the various polarization states; If the second difference is greater than the second threshold, then it is determined that the port to be detected is connected to the optical terminal device; If the second difference is not greater than the second threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

5. A device for detecting port status, characterized in that, The device is applied to point-to-point or multi-point systems, and the device includes a pulse light generation module (4), a beam combiner / splitter (2), and a detector (3); The pulse light generation module (4) is used to generate and output pulse test light. The wavelength of the pulse test light is greater than the reflectivity threshold of the bidirectional optical component, and the pulse width is less than or equal to the target value. The bidirectional optical component belongs to the optical terminal device connected to the port to be tested by optical fiber. The optical combiner / splitter (2) is used to connect to the optical fiber, receive the pulse test light, send the pulse test light to the optical fiber, and receive and output the reflected light transmitted through the optical fiber to the detector (3); The detector (3) is used to determine the first reflection peak information of the reflected light corresponding to the pulse test light at the end of the optical fiber, and the first reflection peak information is used to determine the state of the port to be tested.

6. The apparatus according to claim 5, characterized in that, The detector (3) is used to determine the state of the port to be detected based on the first reflection peak information and the reference reflection peak information corresponding to the pulse test light. The reference reflection peak information is the pulse information of the pulse test light or the reflection peak information generated by the pulse test light on a single reflective surface.

7. The apparatus according to claim 6, characterized in that, The detector (3) is used to determine that the port to be detected is connected to the optical terminal device if the difference between the first width and the second width is greater than the target threshold when the shape of the reflection peak in the first reflection peak information is inconsistent with the shape of the reflection peak in the reference reflection peak information; and if the difference between the first width and the second width is not greater than the target threshold, then the port to be detected is not connected to the optical terminal device. The first width is the width of the reflection peak in the first reflection peak information at the first position, and the second width is the width of the reflection peak in the reference reflection peak information at the first position. When the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information, it is determined that the port to be detected is not connected to the optical terminal device.

8. The apparatus according to any one of claims 5 to 7, characterized in that, The device is connected to the port to be detected via optical fiber or via an optical distribution network.

9. A method for detecting port status, characterized in that, The method is applied to point-to-point or multipoint systems, and the method includes: Test light of multiple polarization states is generated and sent to the optical fiber connected to the port to be tested. The test light of multiple polarization states has the same power and wavelength, and the wavelength difference with the uplink optical signal is less than the wavelength difference threshold. The uplink optical signal is the optical signal sent by the optical terminal equipment connected to the optical fiber. The reflected light transmitted through the optical fiber is received, and the reflected light is detected to obtain the reflected light detection information corresponding to the test light of each polarization state. The state of the port to be tested is determined based on the reflected light detection information corresponding to the test light of each polarization state.

10. The method according to claim 9, characterized in that, The process of generating and sending test light of various polarization states to the optical fibers connected to the ports to be tested, one by one, includes: Generate the first test light; The polarization state of the first test light is adjusted one by one to output test light with the various polarization states one by one.

11. The method according to claim 9 or 10, characterized in that, The test light is direct current light; The step of detecting the reflected light to obtain the reflected light detection information corresponding to each polarization state of the test light includes: The power of the reflected light is detected to obtain the power of the reflected light corresponding to each polarization state of the test light; The determination of the state of the port to be tested based on the reflected light detection information corresponding to the test light of each polarization state includes: Determine the first difference between the maximum and minimum power of the reflected light corresponding to the test light in the various polarization states; If the first difference is greater than the first threshold, then it is determined that the port to be detected is connected to the optical terminal device; If the first difference is not greater than the first threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

12. The method according to claim 9 or 10, characterized in that, The test light is pulsed light; The step of detecting the reflected light to obtain the reflected light detection information corresponding to each polarization state of the test light includes: The reflected light at the end of the optical fiber is detected to obtain the reflection peak height of the reflected light corresponding to each polarization state of the test light at the end of the optical fiber. The determination of the state of the port to be tested based on the reflected light detection information corresponding to the test light of each polarization state includes: Determine the second difference between the maximum and minimum reflection peak heights of the reflected light corresponding to the test light in the various polarization states; If the second difference is greater than the second threshold, then it is determined that the port to be detected is connected to the optical terminal device; If the second difference is not greater than the second threshold, then it is determined that the port to be detected is not connected to the optical terminal device.

13. A method for detecting port status, characterized in that, The method is applied to point-to-point or multipoint systems, and the method includes: A pulsed test light is generated and sent to the optical fiber connected to the port to be tested. The wavelength of the pulsed test light is greater than the reflectivity threshold of the bidirectional optical component, and the pulse width is less than or equal to the target value. The bidirectional optical component belongs to the optical terminal device connected to the port to be tested via the optical fiber. Receive the reflected light transmitted through the optical fiber and determine the first reflection peak information of the reflected light corresponding to the pulse test light at the end of the optical fiber; Based on the first reflection peak information, the state of the port to be detected is determined.

14. The method according to claim 13, characterized in that, Determining the state of the port to be detected based on the first reflection peak information includes: Based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light, the state of the port to be tested is determined. The reference reflection peak information is the pulse information of the pulsed test light or the reflection peak information generated by the pulsed test light on a single reflective surface.

15. The method according to claim 14, characterized in that, The step of determining the state of the port to be tested based on the first reflection peak information and the reference reflection peak information corresponding to the pulsed test light includes: When the shape of the reflection peak in the first reflection peak information is inconsistent with the shape of the reflection peak in the reference reflection peak information, if the difference between the first width and the second width is greater than the target threshold, it is determined that the port to be detected is connected to the optical terminal device; if the difference between the first width and the second width is not greater than the target threshold, it is determined that the port to be detected is not connected to the optical terminal device. The first width is the width of the reflection peak at the first position in the first reflection peak information, and the second width is the width of the reflection peak at the first position in the reference reflection peak information. When the shape of the reflection peak in the first reflection peak information is consistent with the shape of the reflection peak in the reference reflection peak information, it is determined that the port to be detected is not connected to the optical terminal device.

16. A system for detecting port status, characterized in that, The system includes an optical line terminal, a multiplexer / splitter, an optical distribution network, an optical terminal equipment, and the apparatus as described in claim 4, or the apparatus as described in any one of claims 5 to 7; The optical line terminal is connected to the optical combiner / splitter, and the device is connected to the optical combiner / splitter; The optical combiner / splitter is connected to the optical distribution network; The optical distribution network is connected to the optical terminal equipment.

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