WO2024051286A1 - 一种光接入网拓扑的确定方法、装置及系统 - Google Patents

一种光接入网拓扑的确定方法、装置及系统 Download PDF

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Publication number
WO2024051286A1
WO2024051286A1 PCT/CN2023/102644 CN2023102644W WO2024051286A1 WO 2024051286 A1 WO2024051286 A1 WO 2024051286A1 CN 2023102644 W CN2023102644 W CN 2023102644W WO 2024051286 A1 WO2024051286 A1 WO 2024051286A1
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Prior art keywords
optical
time slot
uplink
wavelength
terminal
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PCT/CN2023/102644
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English (en)
French (fr)
Inventor
林华枫
曾小飞
周恩宇
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华为技术有限公司
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Publication of WO2024051286A1 publication Critical patent/WO2024051286A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/572—Wavelength control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems

Definitions

  • the present application relates to the field of optical communication technology, and in particular to a method, device and system for determining the topology of an optical access network.
  • Passive optical network (PON) system includes optical line terminal (OLT), optical distribution network (ODN) and multiple optical terminals located on the user side, such as optical network unit (optical network unit) network unit (ONU) or optical network termination (ONT).
  • OLT optical line terminal
  • ODN optical distribution network
  • ONU optical network unit
  • OTN optical network termination
  • the upstream and downstream optical signals of the PON system can be transmitted in the same optical fiber.
  • the optical signal in the downlink direction (from OLT to optical terminal) works in time division multiplexing (TDM) mode.
  • TDM time division multiplexing
  • the data sent by the OLT will be broadcast to all branch fibers and reach all optical terminals.
  • the optical signal in the upstream direction (optical terminal to OLT) works in time division multiple access (TDMA) mode, and the optical terminal only transmits in authorized time slots.
  • TDMA time division multiple access
  • ODN can transmit optical signals between OLT and multiple optical terminals.
  • the ODN topology is relatively complex.
  • the ODN includes one or more levels of optical splitters to connect the OLT and multiple optical terminals.
  • the connection relationship between the optical terminals and the optical splitters in the ODN is not always unchanged, thus causing problems for operation and maintenance. It brings difficulties for personnel to locate and eliminate faults.
  • Embodiments of the present application provide a method, device and system for determining the topology of an optical access network without the need to modify the ONT, thereby reducing the complexity of implementation.
  • inventions of the present application provide a method for determining the topology of an optical access network.
  • the optical access network includes multiple optical terminals.
  • the multiple optical terminals are connected to different ports of an optical splitter in the optical access network.
  • One-to-one correspondence optical connection the method includes: continuously sending detection light signals of the first wavelength, and controlling the plurality of optical terminals to respectively send uplink optical signals on time slots corresponding to each optical terminal; the first wavelength Corresponding to the first port of the optical splitter, different ports of the optical splitter correspond to different wavelengths; detecting the reflected light of the detection optical signal in the optical signals received on the corresponding time slots of the multiple optical terminals The power of the signal; determining the first wavelength corresponding to the relationship between the time window in which the power of the reflected optical signal of the detection optical signal changes in the received optical signal and the time slots respectively corresponding to the plurality of optical terminals.
  • the optical filters deployed in ODN can be reflection filters or transmission filters, that is, reflection filters or transmission filters are deployed on the branch fibers of the optical splitter.
  • the optical head end continuously sends detection light signals of specific wavelengths, and the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the uplink optical signal of the ONT produces a cross-gain modulation effect or a cross-attenuation modulation effect on the reflected optical signal of the detection optical signal in the gain component of the branch, so that the power of the reflected optical signal of the detection optical signal detected by the optical head is compared with The power of the detection light signal changes (for example, increases or decreases).
  • optical filters correspond to different wavelengths or wavelength combinations, they can reflect or transmit optical signals of different wavelengths or wavelength combinations.
  • Optical filters of different wavelengths correspond to different ports, and the optical head end can bind the optical splitter port to the ONT based on the wavelength of the detected optical signal and the time when the power changes occur. There is no need to modify the ONT and the complexity can be reduced.
  • optical connection between the above two devices can be used to realize the transmission of optical signals between the two devices.
  • Optical connections may be through optical fibers, optical waveguides, or other optical media.
  • the first step is determined based on the relationship between the time window in which the power of the reflected optical signal of the detection optical signal changes in the received optical signal and the time slots respectively corresponding to the multiple optical terminals.
  • the optical terminal connected to the first port corresponding to the wavelength includes:
  • the first optical terminal corresponding to the first time slot and the first optical terminal corresponding to the first wavelength are First port optical connection.
  • inventions of the present application provide a device for determining the topology of an optical access network.
  • the optical access network includes multiple optical terminals.
  • the multiple optical terminals are connected to multiple optical splitters in the optical access network.
  • the ports correspond to optical connections one by one.
  • the device includes a media access control MAC unit, a wavelength-tunable laser, a photodetector and a circulator.
  • the first port of the circulator is optically connected to the wavelength-tunable laser.
  • the second port of the circulator is optically connected to the optical splitter, and the third port of the circulator is optically connected to the photodetector;
  • the MAC unit is used to control the plurality of optical terminals to send uplink optical signals in the time slot corresponding to each optical terminal;
  • the wavelength-tunable laser is used to continuously send a detection light signal of a first wavelength to the optical splitter through a circulator;
  • the photodetector is used to detect the power of the reflected optical signal of the detection optical signal in the optical signal received through the circulator on the time slot corresponding to the multiple optical terminals respectively;
  • the MAC unit is further configured to determine the first time window based on the relationship between the time window in which the power of the reflected optical signal of the detection optical signal changes in the received optical signal and the time slots respectively corresponding to the multiple optical terminals.
  • the optical terminal connected to the first port corresponding to the wavelength;
  • the change in the power of the reflected optical signal of the detection optical signal detected in the received optical signal is: the uplink optical signal of an optical terminal to the detection optical signal and the connection between the optical splitter and the one optical terminal
  • the optical filter in the branch reflects the optical signal obtained by the detection light signal, and produces a cross-gain modulation effect or a cross-attenuation modulation effect in the connection branch.
  • the MAC unit is specifically used for:
  • the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • inventions of the present application provide another method for determining the topology of an optical access network.
  • the optical access network includes multiple Optical terminal, the plurality of optical terminals are optically connected to the plurality of ports of the optical splitter in the optical access network in a one-to-one correspondence.
  • the method includes: continuously sending a pump optical signal of the first wavelength and controlling the plurality of optical terminals.
  • the optical terminal sends uplink optical signals on the time slot corresponding to each optical terminal respectively; the first wavelength corresponds to the first port of the optical splitter, and different ports of the optical splitter correspond to different wavelengths; the measurement is performed on the The received power of the uplink optical signal received on the corresponding time slot of multiple optical terminals; according to the change of the received power of each optical terminal in the multiple optical terminals and the uplink baseline received power of each optical terminal Determine the optical terminal connected to the first port corresponding to the first wavelength; wherein the uplink baseline received power of an optical terminal is between the pump optical signal and the optical splitter before it enters the optical terminal.
  • the received power of the uplink optical signal of an optical terminal is the effect of the pump optical signal on the optical terminal
  • the uplink optical signal is generated by a cross-gain modulation effect or a cross-attenuation modulation effect in the connection branch between the optical splitter and the first optical terminal.
  • Optical filters deployed in ODN can be reflective filters or transmissive filters.
  • the optical head end continuously sends pump optical signals of specific wavelengths, and the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the detection optical signal produces a cross-gain modulation effect or a cross-attenuation modulation effect on the uplink optical signal in the gain component of the branch, thereby causing the power of the uplink optical signal of the optical terminal to change (for example, increase or decrease).
  • different optical filters correspond to different wavelengths or wavelength combinations, they can reflect or transmit optical signals of different wavelengths or wavelength combinations.
  • Optical filters of different wavelengths correspond to different ports, and the optical head end can bind the optical splitter port to the ONT according to the wavelength of the detected optical signal and the time slot of the upstream optical signal where the power changes occur.
  • the step corresponding to the first wavelength is determined based on a change in the received power of each optical terminal among the plurality of optical terminals and the uplink baseline received power of each optical terminal.
  • the optical terminal connected to the first port includes:
  • the difference between the power of the uplink optical signal received in the first time slot and the uplink baseline received power of the first optical terminal corresponding to the first time slot is greater than or equal to the set threshold, and in other than the first time slot
  • the difference between the power of the uplink optical signal received in any other time slot and the uplink baseline received power of the optical terminal corresponding to any other time slot is less than the set threshold, determine the first optical terminal corresponding to the first time slot
  • the first port corresponding to the first wavelength is optically connected; or,
  • the difference between the power of the uplink optical signal received in the first time slot and the uplink baseline received power of the first optical terminal corresponding to the first time slot is less than the set threshold, and in other times except the first time slot If the difference between the power of the uplink optical signal received in any time slot and the uplink baseline received power of the optical terminal corresponding to any other time slot is greater than or equal to the set threshold, it is determined that the first optical signal corresponding to the first time slot
  • the terminal is optically connected to the first port corresponding to the first wavelength.
  • the pump optical signal is modulated by setting information.
  • the change in baseline received power determines the optical terminal connected to the first port corresponding to the first wavelength, including:
  • the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is less than the set threshold, and in When the setting information is detected in the uplink optical signal received in the first time slot, determine that the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength; or,
  • the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is greater than the set threshold, and in When the setting information is detected in the uplink optical signal received in the first time slot, it is determined that the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • the setting information includes a setting frequency and/or a setting code pattern.
  • the method further includes:
  • the plurality of optical terminals are controlled to respectively transmit uplink optical signals on the time slot corresponding to each optical terminal, and the reception of the uplink optical signals by the plurality of optical terminals is measured. power to obtain the uplink baseline received power of each optical terminal in the plurality of optical terminals.
  • inventions of the present application provide a device for determining the topology of an optical access network.
  • the optical access network includes multiple optical terminals.
  • the multiple optical terminals are connected to multiple optical splitters in the optical access network.
  • the ports correspond to optical connections one by one, and the device includes a media access control MAC unit, an optical module and a wavelength-tunable laser;
  • the MAC unit is used to control the plurality of optical terminals to send uplink optical signals in the time slot corresponding to each optical terminal;
  • the wavelength-tunable laser is used to continuously send detection light signals of the first wavelength
  • the optical module is used to measure the received power of uplink optical signals received on the time slots corresponding to the multiple optical terminals;
  • the MAC unit determines, based on changes in the received power of each optical terminal in the plurality of optical terminals and the uplink baseline received power of each optical terminal, that the first port corresponding to the first wavelength is connected to. optical terminal;
  • the uplink baseline received power of an optical terminal is the received power of the uplink optical signal of an optical terminal when the pump optical signal does not enter the optical fiber between the optical splitter and the optical terminal; an optical terminal
  • the change between the received power of the terminal and the uplink baseline received power of the one optical terminal is the difference between the pump optical signal and the uplink optical signal of the one optical terminal in the connection branch between the optical splitter and the first optical terminal. It is caused by the cross-gain modulation effect or the cross-attenuation modulation effect.
  • the MAC unit is specifically used for:
  • the difference between the power of the uplink optical signal received in the first time slot and the uplink baseline received power of the first optical terminal corresponding to the first time slot is greater than or equal to the set threshold, and in other than the first time slot
  • determine the first optical terminal corresponding to the first time slot The first port corresponding to the first wavelength is optically connected; or,
  • the first time slot corresponding to the first time slot is determined.
  • the optical terminal is optically connected to the first port corresponding to the first wavelength.
  • the pump optical signal is obtained through modulation of setting information, and the optical module is also used to detect the uplink optical signals received from the corresponding time slots of multiple optical terminals.
  • the setting information is obtained through modulation of setting information, and the optical module is also used to detect the uplink optical signals received from the corresponding time slots of multiple optical terminals.
  • the MAC unit is specifically used for:
  • the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is less than the set threshold, and in When the setting information is detected in the uplink optical signal received in the first time slot, determine that the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength; or,
  • the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is greater than the set threshold, and in When the setting information is detected in the uplink optical signal received in the first time slot, it is determined that the first optical terminal corresponding to the first time slot and the first optical terminal corresponding to the first wavelength are First port optical connection.
  • the setting information includes a setting frequency and/or a setting code pattern.
  • the MAC unit is further configured to control the plurality of optical terminals to respectively send uplink optical signals in the time slot corresponding to each optical terminal before continuously sending the pump optical signal of the first wavelength. Signal;
  • the optical module is also configured to measure the received power of uplink optical signals of the multiple optical terminals to obtain the uplink baseline received power of each optical terminal in the multiple optical terminals.
  • inventions of the present application provide a method for determining the topology of an optical access network.
  • the optical access network includes multiple optical terminals.
  • the multiple optical terminals are connected to multiple optical splitters in the optical access network. Ports correspond to optical connections one by one, and the method includes:
  • the pump optical signal of the first wavelength Continuously transmit the pump optical signal of the first wavelength, and control the plurality of optical terminals to respectively transmit uplink optical signals on the time slot corresponding to each optical terminal;
  • the first wavelength corresponds to the first port of the optical splitter , different ports of the optical splitter correspond to different wavelengths;
  • the pump optical signal is obtained by modulation of the setting information;
  • the optical terminal connected to the first port corresponding to the first wavelength is determined according to the detection result of each time slot.
  • Optical filters deployed in ODN can be reflective filters or transmissive filters.
  • the pump optical signal of a specific wavelength is continuously sent at the optical head end.
  • the pump light signal can be modulated by setting information. For example, it is obtained by frequency modulation of a set frequency, or code modulation of a set code type.
  • Set the frequency for example, it can be a positive rate wave, of course, other frequencies can also be used.
  • Set the code type for example, it can be a spreading code.
  • the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the detection optical signal produces a cross-gain modulation effect or a cross-attenuation modulation effect on the uplink optical signal in the gain component of the branch, so that the set frequency information or set pattern information in the pump optical signal is modulated to the optical terminal.
  • the binding of the optical splitter port and the ONT can be realized based on the time slot in which the upstream optical signal of the set frequency information or set pattern information is detected and the wavelength of the pump optical signal. There is no need to modify the ONT and the complexity can be reduced.
  • determining the optical terminal connected to the first port corresponding to the first wavelength according to the detection result of each time slot includes:
  • the uplink optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • the setting information includes a setting frequency and/or a setting code pattern.
  • inventions of the present application provide a device for determining the topology of an optical access network.
  • the optical access network includes multiple optical terminals.
  • the multiple optical terminals are connected to multiple optical splitters in the optical access network.
  • the ports correspond to optical connections one by one, and the device includes a media access control MAC unit, an optical module and a wavelength-tunable laser;
  • the MAC unit is used to control the plurality of optical terminals to send uplink optical signals in the time slot corresponding to each optical terminal;
  • the wavelength-tunable laser is used to continuously send a detection light signal of a first wavelength and modulated with setting information
  • the optical module is used to detect the setting information in the uplink optical signals received in the corresponding time slots of the multiple optical terminals to obtain the detection result of each time slot;
  • the MAC unit determines the optical terminal connected to the first port corresponding to the first wavelength according to the detection result of each time slot.
  • the MAC unit is specifically used for:
  • the uplink optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • the setting information includes a setting frequency and/or a setting code pattern.
  • embodiments of the present application provide a system for determining the topology of an optical access network, including the device described in the second aspect, the device described in the fourth aspect, or the device described in the sixth aspect, and the system further includes Optical distribution network ODN and multiple optical terminals, the ODN is optically connected to multiple optical terminals, and the ODN includes one optical splitter or multiple optical splitters;
  • Optical filters are deployed in the connection branches between the optical splitter in the ODN and each of the plurality of optical terminals.
  • the optical filters on different connection branches correspond to different wavelengths and are used to process light of different wavelengths.
  • the signal is reflected or transmitted.
  • a gain component is also deployed in the connection branch between the optical splitter and each optical terminal in the ODN, and the gain component is located between the branch end of the optical splitter and the optical filter. between the filters, or the gain component is located between the optical filter and the optical terminal;
  • the gain component supports generating a cross-gain modulation effect or a cross-attenuation effect on multiple optical signals received at the same time.
  • the optical filter is a Bragg grating FBG.
  • Figure 1 is a schematic diagram of a system architecture provided by an embodiment of the present application.
  • Figure 2 is a schematic diagram of the system structure after the system modification
  • Figure 3A is a schematic diagram of the deployment position of a gain component provided by an embodiment of the present application.
  • Figure 3B is a schematic diagram of another gain component deployment position provided by an embodiment of the present application.
  • Figure 4 is a schematic flowchart of a method for determining the topology of an optical access network described in the first possible implementation manner of the embodiment of the present application;
  • Figure 5A is a schematic diagram of a detection light signal power change in the first possible implementation manner of the embodiment of the present application
  • Figure 5B is a schematic diagram of another detection light signal power change in the first possible implementation manner of the embodiment of the present application.
  • Figure 6 is a device for determining the topology of the optical access network in the first possible implementation of the embodiment of the present application
  • Figure 7A is a schematic diagram of determining the optical access network topology provided in Example 1 of the embodiment of the present application.
  • Figure 7B is a schematic diagram of determining the optical access network topology provided in Example 2 of the embodiment of the present application.
  • Figure 8 is a schematic flowchart of a method for determining the topology of an optical access network described in the second possible implementation manner of the embodiment of the present application;
  • Figure 9 is a device for determining the topology of the optical access network in the second possible implementation of the embodiment of the present application.
  • Figure 10A is a schematic diagram of determining the topology of an optical access network provided in Example 3 of the embodiment of this application;
  • Figure 10B is a schematic diagram for determining another optical access network topology provided in Example 3 of the embodiment of this application.
  • Figure 10C is a schematic diagram of determining the topology of an optical access network provided in Example 4 of the embodiments of this application;
  • Figure 10D is a schematic diagram for determining another optical access network topology provided in Example 4 of the embodiments of this application.
  • Figure 10E is a schematic diagram of determining the topology of an optical access network provided in Example 5 of the embodiments of this application;
  • Figure 10F is a schematic diagram for determining another optical access network topology provided in Example 5 of the embodiment of this application.
  • Figure 10G is a schematic diagram for determining the topology of an optical access network provided in Example 6 of the embodiment of this application;
  • Figure 10H is a schematic diagram for determining another optical access network topology provided in Example 6 of the embodiment of this application.
  • Figure 11 is a schematic flowchart of a method for determining the topology of an optical access network described in the third possible implementation manner of the embodiment of this application;
  • Figure 12 is a device for determining the topology of the optical access network in the third possible implementation of the embodiment of the present application.
  • Figure 13 is a schematic diagram of determining the topology of an optical access network provided in Example 7 of the embodiment of this application.
  • plural means two or more than two.
  • “/” indicates that the related objects are an "or” relationship.
  • A/B can represent A or B; "and/or” in this application is only an association relationship describing related objects. It means that there can be three relationships.
  • a and/or B can mean: A exists alone, A and B exist simultaneously, and B exists alone.
  • a and B can be singular or plural.
  • words such as “first” and “second” are used to distinguish the same or similar items with basically the same functions and effects.
  • the system may be a passive optical network PON system 100.
  • the PON system 100 can be applied to optical access networks.
  • the PON system 100 includes at least one optical line terminal OLT 110, an optical distribution network ODN 120 and a plurality of optical terminals.
  • the optical terminal is an ONT as an example.
  • OLT110 is connected to multiple ONT130 through ODN120.
  • the direction from OLT110 to ONT130 is defined as the downlink direction
  • the direction from ONT130 to OLT110 is defined as the uplink direction.
  • the PON system 100 may be a communication network that does not require any active devices to realize data distribution between the OLT 110 and the ONT 130 .
  • data distribution between OLT110 and ONT130 can be through ODN120 It is realized by passive optical components (such as optical splitters).
  • the PON system 100 may be an asynchronous transfer mode passive optical network (ATM PON) system or a broadband passive optical network (BPON) system or a Gigabit passive optical network.
  • ATM PON asynchronous transfer mode passive optical network
  • BPON broadband passive optical network
  • Gigabit passive optical network Gigabit passive optical network
  • gigabit passive optical network GPON
  • Ethernet passive optical network EPON
  • NG PON next-generation passive optical network
  • 10 gigabit passive Optical network 10gigabit-capable passive optical network, XG-PON
  • 10Gigabit ethernet passive optical network 10Gigabit ethernet passive optical network, 10GEPON, etc.
  • OLT110 is usually located in a central location, such as a central office (CO), which can uniformly manage one or more ONT130.
  • OLT110 can forward the received downlink data to ONT130 through ODN120, and forward the uplink data received from ONT130.
  • CO central office
  • the ONT 130 can be disposed in a distributed manner at user side locations (such as user premises).
  • the ONT 130 may be a device used to communicate with the OLT 110 and the user. Specifically, the ONT 130 may act as a communication link between the OLT 110 and the user.
  • ONT 130 may forward the downlink data received from OLT 110 to the user, and forward the data received from the user as uplink data to OLT 110 through ODN 120.
  • ONT130 is generally applied to end users, such as optical modems, etc.; while ONU can be applied to end users, and can also be connected to end users through other networks (such as Ethernet).
  • ONT130 is taken as an example for description, and ONT130 and ONU are interchangeable.
  • ODN 120 may include optical fibers, optical couplers, optical splitters, and/or other devices.
  • the optical fibers, optical couplers, optical splitters, and/or other devices may be passive optical devices. That is, the optical fibers, optical couplers, optical splitters and/or other devices may be devices that do not require power supply support to distribute data signals between the OLT 110 and the ONT 130 .
  • ODN 120 may also include one or more active devices, such as optical amplifiers or relay devices.
  • ODN120 can specifically extend from OLT110 to multiple ONT130 using two-level splitting, but it can also be configured as any other point-to-multipoint (such as one-level splitting or multi-level splitting) or point To the point structure.
  • the embodiments of this application are described using two-level spectroscopy as an example.
  • One-level spectroscopy and multi-level spectroscopy are similar, and this application is not limited thereto.
  • ODN120 uses optical splitters to achieve data distribution.
  • ODN120 can be deployed in a two-level optical splitting method, including a first-level optical splitter 121 and multiple second-level optical splitters.
  • Spectrometer 122 The common end of the first-level optical splitter 121 is connected to the OLT 110 through a trunk optical fiber, and its branch ends are respectively connected to the common end of the second-level optical splitter 122 through distribution optical fibers.
  • Each second-level optical splitter 122 The branch ends are further connected to the corresponding uplink ports of ONT130 through branch optical fibers.
  • the downlink data signal sent by the OLT 110 first passes through the first-stage optical splitter 121 for the first splitting, and then passes through the second-stage optical splitter 122 for the second splitting, thereby forming multiple downlink optical signals and transmitting them to Each ONT130.
  • the upstream data signals sent by each ONT 130 are sequentially combined through the second-stage optical splitter 122 and the first-stage optical splitter 121 and then transmitted to the OLT 110 .
  • the second-stage optical splitter 122 is the final optical splitter
  • the first-level optical splitter 121 is the previous optical splitter connected to the final optical splitter
  • the first-level optical splitter is the final optical splitter
  • the third-level optical splitter is the final optical splitter
  • the second-level optical splitter is the previous optical splitter connected to the final optical splitter.
  • the first-level optical splitter is the previous-level optical splitter connected to the second-level optical splitter. It can be seen from the above that the final optical splitter in this application refers to the optical splitter closer to the ONT.
  • OLT110 and multiple ONT130 are connected through one or more levels of optical splitters. Since the connection relationship is not always constant, operation and maintenance personnel need to know in advance the relationship between OLT110 and multiple ONTs when locating and eliminating faults. Connection topology in ODN.
  • one possible implementation method as shown in Figure 2, is to add a reflective or transmissive filter to the optical splitter, deploy an absorption band (U-band) tunable laser in the CO, and add a U-band to the ONT. band receiver.
  • U-band absorption band
  • the U-band tunable laser emits optical signals of different wavelengths, and then the ONT detects whether it receives the optical signal of that wavelength to determine the binding relationship between the ONT and the optical splitter port.
  • the OLT first controls the U-band tunable laser to send an optical signal with wavelength ⁇ 1, and sends a message requesting all ONTs to report whether they have received U-band optical signals. Then the U-band adjustable laser is controlled to send an optical signal with a wavelength of ⁇ 9, and a message is sent to request all ONTs to report whether they have received U-band optical signals. Based on the data reported twice by all ONTs, if an ONT does not receive U-band optical signals twice, it can be determined that the ONT is connected to port 1 of the primary optical splitter and port 1 of the secondary optical splitter.
  • the port 1 of the primary optical splitter or the branch fiber of port 1 has a reflective filter with wavelength ⁇ 1, which is used to reflect the optical signal with wavelength ⁇ 1.
  • the branch fiber of port 1 of the secondary optical splitter has a reflective filter of wavelength ⁇ 9, which is used to reflect the optical signal of wavelength ⁇ 1.
  • Different ports of different optical splitters correspond to reflective filters of different wavelengths.
  • transmission filters are used in ODN.
  • the OLT first controls the U-band tunable laser to send an optical signal with wavelength ⁇ 1, and sends a message requesting all ONTs to report whether they have received U-band optical signals. Then the U-band adjustable laser is controlled to send an optical signal with a wavelength of ⁇ 9, and a message is sent to request all ONTs to report whether they have received U-band optical signals. Based on the data reported twice by all ONTs, if an ONT receives U-band optical signals twice, it can be determined that the ONT is connected to port 1 of the primary optical splitter and port 1 of the secondary optical splitter.
  • port 1 of the primary optical splitter or the branch fiber of port 1 is provided with a transmission filter, which is used to transmit at least optical signals with wavelengths ⁇ 1 and ⁇ 9.
  • a transmission filter on the branch fiber of port 1 of the secondary optical splitter which is used to transmit at least the optical signal of wavelength ⁇ 9.
  • Different ports of different optical splitters correspond to transmission filters of different wavelengths or wavelength combinations.
  • each device in the PON system needs to be modified before it can be realized.
  • the number of optical terminals is large and the transformation is difficult, thus increasing the complexity of implementation.
  • embodiments of the present application provide a method, device and system for determining the topology of an optical access network.
  • operation and maintenance personnel can quickly locate the port to which the optical terminal is connected or the optical fiber link corresponding to the port based on the determined binding relationship (or connection relationship) to detect the fault.
  • this application does not require modification of optical terminal equipment, can reduce implementation complexity, and reduce waste of resources caused by manual modification.
  • the upstream data of different ONTs are transmitted upward through their respective branch optical fibers, and the data are merged after passing through the optical splitter.
  • the uplink uses time division multiplexing to transmit data.
  • the uplink is divided into different time slots.
  • the time slot in which each ONT sends data is strictly scheduled and authorized by the OLT, and the ONT can only respond passively.
  • dynamic bandwidth allocation OLT has dynamic bandwidth allocation (DBA) function.
  • the OLT monitors PON congestion in real time through the DBA module, and dynamically adjusts the bandwidth of the ONT based on congestion, current bandwidth utilization, and configuration conditions.
  • static bandwidth allocation also called fixed bandwidth allocation.
  • the bandwidth occupied by each ONT is fixed, and the OLT can periodically allocate a fixed length of authorization to each ONT based on each ONT's bandwidth, latency and other indicators.
  • the principle of using different ONTs to send optical signals in different time slots is used.
  • Different branches in the optical splitter pair According to different wavelengths, detection optical signals of different wavelengths are sent through the OLT, so as to monitor the changes of the received optical signals in different time slots, thereby determining the optical terminal corresponding to the changed time slot and the optical splitter branch corresponding to the wavelength. port binding relationship.
  • the embodiments of the present application mainly use the cross-modulation effect produced by the detection optical signal and the uplink optical signal of the optical terminal in the branch of the optical splitter to cause changes in the optical signal received by the OLT.
  • Cross-modulation refers to the modulation of one signal on the carrier of another signal produced by the interaction between signals in non-linear equipment, networks or transmission materials.
  • Cross modulation can be cross gain modulation or cross attenuation modulation.
  • optical filters and gain components are deployed in the connection branches between the optical splitter and the ONT.
  • the optical filter can be either a reflective filter or a transmissive filter.
  • the optical filter can use fiber Bragg grating (FBG).
  • the gain component may use an optical amplifier or other device with gain modulation function.
  • the functions of the optical filter and the gain component can be integrated into one component.
  • the connection channel between the optical splitter and the ONT uses FBG-doped optical fiber with reflection or transmission function.
  • the optical filter and gain component can be implemented by different components, and the optical filter can be deployed on the branch optical fiber.
  • the gain component can be deployed on the branch end (also called branch end) optical fiber between the optical filter and the optical splitter or on the port of the optical splitter, as shown in Figure 3A.
  • the gain component can also be located between the optical filter and the optical terminal, as shown in Figure 3B.
  • This application exemplarily provides three possible ways to determine the topology information of the optical access network without modifying the ONT.
  • the optical filter deployed in the ODN can be a reflective filter or a transmissive filter, that is, a reflective filter or a transmissive filter is deployed on the branch fiber of the optical splitter.
  • the optical head end continuously sends detection light signals of specific wavelengths, and the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the uplink optical signal of the ONT produces a cross-gain modulation effect or a cross-attenuation modulation effect on the reflected optical signal of the detection optical signal in the gain component of the branch, so that the power of the reflected optical signal of the detection optical signal detected by the optical head is compared with The power of the detection light signal changes (for example, increases or decreases).
  • optical filters correspond to different wavelengths or wavelength combinations, they can reflect or transmit optical signals of different wavelengths or wavelength combinations.
  • Optical filters of different wavelengths correspond to different ports, and the optical head end can bind the optical splitter port to the ONT based on the wavelength of the detected optical signal and the time when the power changes occur.
  • the optical filters deployed in the ODN can be reflective filters or transmissive filters.
  • the optical head end continuously sends pump optical signals of specific wavelengths, and the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the detection optical signal produces a cross-gain modulation effect or a cross-attenuation modulation effect on the uplink optical signal in the gain component of the branch, thereby causing the power of the uplink optical signal of the optical terminal to change (for example, increase or decrease).
  • different optical filters correspond to different wavelengths or wavelength combinations, they can reflect or transmit optical signals of different wavelengths or wavelength combinations.
  • Optical filters of different wavelengths correspond to different ports, and the optical head end can bind the optical splitter port to the ONT according to the wavelength of the detected optical signal and the time slot of the upstream optical signal where the power changes occur.
  • the optical filters deployed in the ODN can be reflective filters or transmissive filters.
  • the pump optical signal of a specific wavelength is continuously sent at the optical head end.
  • the pump light signal can be modulated by setting information. For example, it is obtained by frequency modulation of a set frequency, or code modulation of a set code type.
  • Set the frequency for example, it can be a positive rate wave, of course, other frequencies can also be used.
  • Set the code type for example, it can be a spreading code.
  • the optical head end controls multiple optical terminals in the optical access network to send uplink optical signals in corresponding time slots.
  • the detection optical signal produces a cross-gain modulation effect or a cross-attenuation modulation effect on the uplink optical signal in the gain component of the branch, so that the pump optical signal
  • the set frequency information or set code type information in the signal is modulated onto the uplink optical signal of the optical terminal, and then the time slot and pump where the uplink optical signal of the set frequency information or set code type information is located can be detected.
  • the wavelength of the optical signal is used to bind the optical splitter port to the ONT.
  • Figure 4 is a schematic flow chart of a method for determining the topology of an optical access network in a first possible implementation manner.
  • the optical access network including N optical terminals as an example.
  • N optical terminals are optically connected in a one-to-one correspondence with N ports included in multiple optical splitters in the optical access network.
  • N is a positive integer.
  • the ODN in the optical access network uses a first-level optical splitter, and the first-level optical splitter includes at least N ports, and N optical terminals are optically connected to N ports among at least N ports in a one-to-one correspondence.
  • the ODN in the optical access network uses multi-level optical splitters, such as two-level, three-level, etc.
  • Multiple final optical splitters in ODN include at least N ports. For example, if there are three final-stage optical splitters, the total number of ports of the three final-stage optical splitters is greater than or equal to N, and N optical terminals are optically connected to N ports of the three final-stage optical splitters in one-to-one correspondence.
  • the method for determining the optical access network topology provided in Figure 4 specifically includes the following steps:
  • the first wavelength corresponds to the first port of the optical splitter, and different ports of the optical splitter correspond to different wavelengths.
  • the optical splitter here may refer to the last-level optical splitter, the upper-level optical splitter, or the first-level optical splitter, which is not specifically limited in this application. Taking a two-stage optical splitter as an example, the first wavelength may correspond to port 1 of the first-stage optical splitter or to port 1 of the second-stage optical splitter.
  • the DBA method can be used to allocate the uplink light-emitting time slot to each optical terminal, or the static bandwidth allocation method can be used to allocate the uplink light-emitting time slot (referred to as the time slot) to each optical terminal.
  • the detection optical signal after the detection optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has the function of reflecting the detection optical signal of the first wavelength.
  • the optical filter reflects back the detection light signal of this wavelength.
  • the optical filters deployed on the branches of other optical splitters at the same level transmit the detection light signals of the first wavelength.
  • the detection optical signal after the detection optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has the ability to transmit the detection optical signal of the first wavelength. Function, the optical filter transmits the detection light signal of this wavelength.
  • the optical filters deployed on the branches of other optical splitters at the same level reflect back the detection light signals of the first wavelength.
  • the change in the power of the reflected optical signal of the detection optical signal detected in the received optical signal is: the uplink optical signal of an optical terminal to the detection optical signal and the connection between the optical splitter and the one optical terminal
  • the optical filter in the branch reflects the optical signal obtained by the detection light signal, and produces a cross-gain modulation effect or a cross-attenuation modulation effect in the connection branch.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical terminal connected to the first port corresponding to the first wavelength is determined based on the relationship between the time when the power of the reflected optical signal changes and the time slots corresponding to the plurality of optical terminals, it may be This is achieved in the following manner: when it is determined that the time window in which the power of the reflected optical signal detected in the received optical signal changes is located in the first time slot, it is determined that the first optical terminal corresponding to the first time slot is the same as the first optical terminal.
  • the first port corresponding to the wavelength is optically connected.
  • the method for determining the topology of the optical access network can be implemented by a device for determining the topology of the optical access network.
  • the device can be deployed at the optical head end, such as in an OLT.
  • the device can also be deployed in CO.
  • the device includes a media access control (media access control, MAC) unit 510, a wavelength tunable laser (tunable laser, TL) 520, a photodetector 530 and a circulator 540.
  • the first port of the circulator 540 is optically connected to the wavelength-tunable laser 520
  • the second port of the circulator 540 is optically connected to the ODN
  • the third port of the circulator 540 is optically connected to the photodetector 530 .
  • Wavelength-tunable lasers can also be called tunable lasers (tunable lasers, TL).
  • the MAC unit 510 can use a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a system on chip (SoC).
  • the central processor central processor unit, CPU
  • the central processor can also be a network processor (Network Processor, NP), a digital signal processing circuit (digital signal processor, DSP), or a microcontroller (micro controller unit, MCU), programmable logic device (PLD) or other integrated chips can also be used.
  • the wavelength-tunable laser 520 can emit detection light signals of multiple wavelengths. When identifying the branch branch (port of the branch) connected to the target ONT (any ONT connected to the ODN), the OLT can control the wavelength-adjustable laser 520 to emit detection light signals of multiple wavelengths.
  • the signal is the wavelength of the detection light signal reflected or transmitted by the optical filter set on each branch.
  • the photodetector 530 can detect the detection light signal emitted by the wavelength-tunable laser 520 and received by the circulator and the laser reflected back through the ODN.
  • the MAC unit 510, the wavelength-tunable laser 520, the photodetector 530 and the circulator 540 can be integrated into one chip, or can be implemented through different chips.
  • the MAC unit 510 is implemented by a chip, such as called a MAC chip.
  • the wavelength-tunable laser 520, the photodetector 530 and the circulator 540 can be integrated into a chip, such as an OAI chip.
  • the MAC unit 510 is deployed in the OLT, and the wavelength-tunable laser 520, the photodetector 530, and the circulator 540 are integrated in one chip, deployed outside the OLT, and optically connected to the OLT.
  • the MAC unit 510 controls multiple optical terminals to respectively send uplink optical signals on the time slot corresponding to each optical terminal.
  • the wavelength-tunable laser 520 continuously sends the detection light signal of the first wavelength to the optical splitter through the circulator 540 .
  • the photoelectric detector (PD) 530 can detect the power of the reflected optical signal of the detection optical signal from the optical signal received on each time slot through the circulator 540.
  • the MAC unit 510 determines the first wavelength corresponding to the first wavelength based on the relationship between the time window in which the power of the reflected optical signal changes is detected in the received optical signal and the time slots respectively corresponding to the multiple optical terminals.
  • An optical terminal connected to a port.
  • the deployment position relationship between the gain component and the optical filter is as shown in Figure 3A.
  • the optical filters deployed on the branches of the optical splitter are all reflective filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of reflecting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals are all It has the function of transmitting an optical signal of the first wavelength.
  • the optical filter in the connection branch between the optical splitter and the first optical terminal performs a reflection operation on the detection light signal of the first wavelength, thereby reflecting back the detection light signal of the first wavelength.
  • the optical filter on the branch corresponding to the port of the optical splitter connected to other optical terminals does not reflect the detection light signal of the first wavelength, but directly transmits it. Therefore, the reflected optical signal that is not detected in the optical signals corresponding to the time slots of other optical terminals, that is, the power does not fluctuate.
  • the uplink optical signal of the first optical terminal produces a cross-gain modulation effect or a cross-attenuation modulation effect on the gain component of the connection branch on the detection optical signal, and for the connection between the optical splitter and the first
  • the optical filter in the connection branch of the optical terminal reflects the optical signal obtained by the detection light signal, and a cross-gain modulation effect or a cross-attenuation modulation effect is also produced on the gain component of the connection branch, so that in the first light
  • the detection optical signal among the optical signals detected on the time slot of the terminal is enhanced or weakened.
  • the detection light signal passes through the optical filter of the connecting branch of the optical splitter connected to other optical terminals, it is transmitted out, that is, no reflected light signal of the detection light signal is generated, so the uplink optical signals of other optical terminals are also There is no cross-gain modulation effect or cross-attenuation modulation effect on the reflected optical signal. This ensures that the reflected optical signal that is not detected on the time slots of other optical terminals, that is, the power of the reflected optical signal will not be enhanced or weakened (approximately 0). Further, it can be determined that the power of the detection light signal detected in the uplink optical signal received in the time slot of the first optical terminal is compared with the power of the detection light signal detected in the uplink optical signal received in other time slots. The power fluctuates, such as increasing or decreasing.
  • the power of the detection light signal is expressed as P OAI
  • the power of the detection light signal detected in the received optical signal is expressed as P OAI_R .
  • the power of the detection optical signal detected in the uplink optical signal received in the time slot of the first optical terminal is compared with the power of the detection optical signal detected in the uplink optical signal received in other time slots.
  • FIG. 5B shows that the power of the detection optical signal detected in the uplink optical signal received in the time slot of the first optical terminal is compared with the power of the detection optical signal detected in the uplink optical signal received in other time slots. Enhancement occurs.
  • the optical terminal connected to the first port of the optical splitter after determining the optical terminal connected to the first port of the optical splitter, continue to determine the optical terminals connected to other ports. For example, continue to send the detection light signal of the second wavelength, and the second wavelength corresponds to the second port of the optical splitter.
  • the optical terminal connected to the second port has been determined, and so on, until all the optical terminals are determined. The optical terminal connected to the port.
  • the optical access network includes 64 ONTs, namely ONT1-ONT64.
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • the MAC unit 510 is deployed in the OLT.
  • the OLT also has other components, such as optical modules, which are not shown in Figure 7A.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • a gain component refers to a component that causes two optical signals to produce a cross-gain modulation effect or a cross-attenuation modulation effect.
  • the gain component may be a semiconductor optical amplifier or a doped optical fiber.
  • Different optical filters are reflective filters, used to reflect optical signals of different wavelengths.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 520 is adjusted to the wavelength ⁇ 1 and continuously emits detection light signals of the wavelength ⁇ 1.
  • the power of the detection light signal is P OAI .
  • the detection light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the detection light signal of wavelength ⁇ 1 is reflected back when passing through the optical filter of the branch of port 1.
  • the detection light signal with wavelength ⁇ 1 is directly transmitted when passing through the optical filter of the port 2-port 64 branch.
  • the MAC unit 510 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the uplink optical signal of ONT1 when passing through the gain component, the uplink optical signal of ONT1 reflects back the detection light signal of wavelength ⁇ 1 and the detection light signal of wavelength ⁇ 1 through the optical filter.
  • the signal produces a cross-gain modulation effect or a cross-attenuation modulation effect.
  • the photodetector 530 detects the power of the detection light signal from the received light signal, which can be understood as the power of the reflected light signal of the detection light signal.
  • the power of the detection light signal detected by the photodetector 530 in time slot 1 will fluctuate (increase or decrease) compared with the power of the detection light signal detected in other time slots.
  • the dotted line in Figure 7A represents the signal flow direction of the detection light signal.
  • Photodetector 530 can detect the time window in which power fluctuations occur.
  • the MAC unit 510 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser, the time window in which the power fluctuates, and the time slot in which each ONT sends uplink optical signals, that is, there is a binding relationship.
  • the MAC unit controls the wavelength-tunable laser 520 to send a detection light signal of wavelength ⁇ 2, and continues to determine the optical terminal connected to port 2 corresponding to wavelength ⁇ 2.
  • the optical filters deployed on the branches of the optical splitter are all transmission filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of transmitting optical signals of the first wavelength and reflecting the optical signals of other wavelengths.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of reflecting the optical signal of the first wavelength.
  • the optical filter in the connection branch between the optical splitter and the first optical terminal performs a transmission operation on the detection light signal of the first wavelength, thereby transmitting the detection light signal of the first wavelength.
  • the optical filter on the branch corresponding to the port of the optical splitter connected to other optical terminals reflects the detection light signal of the first wavelength. Therefore, the power of the detection optical signal detected in the optical signal received on the corresponding time slot of other optical terminals is all enhanced or weakened, while the detection light of the optical signal received on the time slot of the first optical terminal is not detected.
  • the reflected light signal of the signal that is, the power, does not increase or decrease. Therefore, the power of the detection optical signal detected in the optical signal received in the time slot of the first optical terminal fluctuates compared with the power of the detection optical signal detected in the optical signal received in the time slot of other optical terminals.
  • the uplink optical signals of other optical terminals produce a cross-gain modulation effect or a cross-attenuation modulation effect on the gain components of the corresponding connection branches on the detection optical signal, and for the optical splitter and the first
  • the optical filter in the connection branch of the optical terminal reflects the optical signal obtained by the detection optical signal, and a cross-gain modulation effect or a cross-attenuation modulation effect will also be produced on the gain component of the connection branch, so that in other optical terminals
  • the power of the detection optical signal detected in the optical signal received on the corresponding time slot is all enhanced or all weakened.
  • the detection light signal passes through the optical filter of the connecting branch of the optical splitter connected to the first optical terminal, the detection light signal is transmitted out, that is, no reflected light signal of the detection light signal is generated, so the first optical terminal
  • the uplink optical signal will not have a cross-gain modulation effect or a cross-attenuation modulation effect on the reflected optical signal. That is, the reflected optical signal of the detection optical signal is not detected by the optical signal received on the time slot of the first optical terminal, that is, the power of the reflected optical signal on the time slot of the first optical terminal is not enhanced or weakened.
  • the power of the detection light signal detected in the uplink optical signal received in the time slot of the first optical terminal is compared with the power of the detection light signal detected in the uplink optical signal received in other time slots. Power fluctuates, such as increasing or decreasing.
  • the optical access network includes 64 ONTs, namely ONT1-ONT64.
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • the MAC unit 510 is deployed in the OLT.
  • the OLT also has other components, such as optical modules, etc., which are not shown in Figure 7B.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • a gain component refers to a component that causes two optical signals to produce a cross-gain modulation effect or a cross-attenuation modulation effect.
  • the gain component may be a semiconductor optical amplifier or a doped optical fiber.
  • Different optical filters are transmission filters, used to transmit optical signals of different wavelengths.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 520 is adjusted to the wavelength ⁇ 1 and continuously emits detection light signals of the wavelength ⁇ 1.
  • the power of the detection light signal is P OAI .
  • the detection light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the detection light signal of wavelength ⁇ 1 is transmitted through the optical filter of the branch of port 1.
  • the detection light signal with wavelength ⁇ 1 is reflected back when passing through the optical filter of the branch from port 2 to port 64.
  • the MAC unit 510 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the detection optical signal of wavelength ⁇ 1 is transmitted through the optical filter of the branch of the optical splitter corresponding to ONT1.
  • the uplink optical signals of ONT2-ONT64 when passing through the gain component, produce a cross-gain modulation effect or cross-over on the detection light signal of wavelength ⁇ 1 and the reflected light signal of the detection light signal.
  • the power of the detected optical signal in the optical signals detected on the corresponding time slots of ONT2-ONT64 is enhanced or weakened. That is to say, the power of the detected optical signals among the optical signals detected on the corresponding time slots of ONT2-ONT64 are approximately the same. Since the detection light signal of wavelength ⁇ 1 is transmitted through the optical filter of the branch of the optical splitter corresponding to ONT1, the power of the detection light signal in the optical signal detected on the time slot corresponding to ONT1 is not enhanced. or weakened. The power of the detection light signal detected by the photodetector 530 in time slot 1 will fluctuate (increase or decrease) compared with the power of the detection light signal detected in other time slots. For example, see Figure 7B.
  • Photodetector 530 can detect the time window in which power fluctuations occur. Further, the MAC unit 510 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser, the time window in which the power fluctuates, and the time slot in which each ONT sends uplink optical signals, that is, there is a binding relationship.
  • the MAC unit controls the wavelength-tunable laser 520 to send a detection light signal of wavelength ⁇ 2, and continues to determine the optical terminal connected to port 2 corresponding to wavelength ⁇ 2.
  • FIG 8 is a schematic flow chart of a method for determining the topology of an optical access network in a second possible implementation manner.
  • the optical access network including N optical terminals as an example.
  • N optical terminals are optically connected in a one-to-one correspondence with N ports included in multiple optical splitters in the optical access network.
  • N is a positive integer.
  • the ODN in the optical access network uses a first-level optical splitter, and the first-level optical splitter includes at least N ports, and N optical terminals are optically connected to N ports among at least N ports in a one-to-one correspondence.
  • the ODN in the optical access network uses multi-level optical splitters, such as two-level, three-level, etc.
  • Multiple final optical splitters in ODN include at least N ports. For example, if there are three final-stage optical splitters, the total number of ports of the three final-stage optical splitters is greater than or equal to N, and N optical terminals are optically connected to the N ports of the three final-stage optical splitters in one-to-one correspondence.
  • the method for determining the optical access network topology provided in Figure 8 specifically includes the following steps:
  • the first wavelength corresponds to the first port of the optical splitter, and different ports of the optical splitter correspond to different wavelengths.
  • the optical splitter here may refer to the final optical splitter, the upper optical splitter, or the first optical splitter, which is not specifically limited in this application. Taking a two-stage optical splitter as an example, the first wavelength may correspond to port 1 of the first-stage optical splitter or to port 1 of the second-stage optical splitter.
  • the DBA method can be used to allocate the uplink light-emitting time slot to each optical terminal, or the static bandwidth allocation method can be used to allocate the uplink light-emitting time slot (referred to as the time slot) to each optical terminal.
  • the pump optical signal after the pump optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has a function of reflecting the detection optical signal of the first wavelength. Function, the optical filter reflects the pump light signal of this wavelength back.
  • the optical filters deployed on the branches of other optical splitters at the same level transmit the detection light signals of the first wavelength.
  • the pump optical signal after the pump optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has the ability to transmit the pump light of the first wavelength.
  • the function of the signal is that the optical filter transmits the detection light signal of this wavelength.
  • the optical filters deployed on the branches of other optical splitters at the same stage reflect back the pump optical signals of the first wavelength.
  • the uplink baseline received power of an optical terminal is the received power of the uplink optical signal of the one optical terminal when the pump optical signal does not enter the connection branch between the optical splitter and the one optical terminal;
  • the change between the received power of an optical terminal and the uplink baseline received power of the one optical terminal is the difference between the pump optical signal and the uplink optical signal of the one optical terminal at the connection between the optical splitter and the first optical terminal. It is caused by the cross-gain modulation effect or the cross-attenuation modulation effect in the branch.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the difference between the power of the uplink optical signal received in the first time slot and the uplink baseline received power of the first optical terminal corresponding to the first time slot is greater than or equal to the set threshold, and in any other time slot except the first time slot
  • the first time slot corresponding to the first time slot is determined.
  • the optical terminal is optically connected to the first port corresponding to the first wavelength.
  • the uplink baseline received power is represented by P rx .
  • the measured received power is passed through express.
  • the received power difference corresponding to time slot i passes express. Satisfy the following formula (1) or formula (2).
  • the above formula (1) when the cross-modulation effect produced by the branches of the optical splitter is a cross-gain modulation effect, the above formula (1) is used.
  • the cross-modulation effect produced by the branches of the optical splitter is a cross-attenuation modulation effect, the above formula (1) is used. 2).
  • the optical terminal connected to the first port of the optical splitter after determining the optical terminal connected to the first port of the optical splitter, continue to determine the optical terminals connected to other ports. For example, continue to send a pump optical signal of a second wavelength.
  • the second wavelength corresponds to the second port of the optical splitter.
  • the multiple optical terminals are controlled to respectively send uplink optical signals on the time slot corresponding to each optical terminal, and the optical signals of the multiple optical terminals are measured.
  • the received power of the uplink optical signal is used to obtain the uplink baseline received power of each optical terminal in the plurality of optical terminals.
  • the laser on the optical terminal is an uncooled laser, and the emission power of the uncooled laser is easily affected by temperature changes.
  • the time interval between calibrating the uplink baseline received power and triggering the determination of the optical terminal connected to the optical splitter port can be shortened.
  • the wavelength adjustment time of the wavelength-tunable laser is 5 seconds and the calibration time of the uplink baseline received power is 3.2 ms, then the wavelength-tunable laser should be controlled in advance to start the wavelength adjustment independently before calibrating and recording the uplink baseline received power. , and ensure that during the uplink baseline received power calibration process, the pump optical signal does not enter the optical fiber to avoid interfering with the baseline received power calibration.
  • the method for determining the optical access network topology provided in Figure 8 can be implemented by a device for determining the optical access network topology.
  • the device can be deployed at the optical head end, such as in an OLT.
  • the device includes a media access control (media access control, MAC) unit 910, a wavelength tunable laser (tunable laser, TL) 920 and a power meter 930.
  • media access control media access control, MAC
  • tunable laser tunable laser
  • the MAC unit 910 may adopt an FPGA, an ASIC, or an SoC, a CPU, an NP, a DSP, an MCU, a PLD or other integrated chips.
  • the wavelength-tunable laser 920 can emit pump light signals of multiple wavelengths.
  • the OLT can control the wavelength-adjustable laser 920 to emit pump optical signals of multiple wavelengths.
  • the pump light signal is the wavelength of the pump light signal reflected by the optical filter provided on each branch.
  • the power meter can be an optical module 930 or a received signal strength indicator (Received Signal Strength Indicator, RSSI).
  • the optical module 930 is taken as an example.
  • the optical module 930 is taken as an example.
  • the MAC unit 910, TL920 and optical module 930 can be integrated into one chip, or can be implemented by different chips.
  • the MAC unit 910 controls multiple optical terminals to send uplink optical signals on the time slot corresponding to each optical terminal.
  • the wavelength-tunable laser 920 continuously sends a pump light signal of the first wavelength to the optical splitter.
  • the optical module 930 is configured to measure the received power of the uplink optical signals received on the time slots respectively corresponding to the multiple optical terminals.
  • the MAC unit 910 determines the first port corresponding to the first wavelength based on the change of the received power of each optical terminal in the plurality of optical terminals compared to the uplink baseline received power of each optical terminal.
  • the connected optical terminal determines the first port corresponding to the first wavelength based on the change of the received power of each optical terminal in the plurality of optical terminals compared to the uplink baseline received power of each optical terminal.
  • the deployment position relationship between the gain component and the optical filter is as shown in Figure 3A.
  • the optical filters deployed on the branches of the optical splitter are all reflective filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of reflecting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of transmitting optical signals of the first wavelength.
  • the optical filter in the connecting branch between the optical splitter and the first optical terminal performs a reflection operation on the pump optical signal of the first wavelength, thereby reflecting the pump optical signal of the first wavelength back, thereby Both the pump optical signal of the first wavelength and the optical signal generated by reflecting the pump optical signal through the optical filter produce a cross-modulation effect on the uplink optical signal of the first optical terminal in the gain component. Because the optical filter on the branch corresponding to the port of the optical splitter connected to other optical terminals does not reflect the pump optical signal of the first wavelength, but directly transmits it.
  • the pump optical signal of the first wavelength produces a cross-modulation effect on the uplink optical signal of the first optical terminal, and there is no cross-modulation effect caused by the reflected optical signal on the uplink optical signal. Therefore, the uplink optical signal received in the time slot corresponding to other optical terminals has a small power change amplitude due to the pump optical signal.
  • the pump optical signal of the first wavelength and the optical signal generated by reflecting the pump optical signal through the optical filter produce a cross-modulation effect on the uplink optical signal of the first optical terminal in the gain component, causing the uplink optical signal of the first optical terminal to The received power changes significantly.
  • the received power of the uplink optical signal of the first optical terminal changes significantly compared with the baseline received power, that is, it is determined that the received power of the uplink optical signal detected in the first time slot is compared with the received power of the uplink optical signal corresponding to the first time slot.
  • the baseline received power changes significantly, thereby determining that there is a binding relationship between the first optical terminal corresponding to the first time slot and the branch end of the optical splitter corresponding to the first wavelength.
  • the method for determining the topology of the optical access network will be described in conjunction with FIG. 9 .
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • a gain component refers to a component that causes two optical signals to produce a cross-gain modulation effect or a cross-attenuation modulation effect.
  • the gain component may be a semiconductor optical amplifier or a doped optical fiber.
  • Different optical filters are used to reflect optical signals of different wavelengths or combinations of wavelengths.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 920 is adjusted to the wavelength ⁇ 1 and continuously emits a pump light signal of the wavelength ⁇ 1.
  • the pump light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the pump optical signal of wavelength ⁇ 1 is reflected back when passing through the optical filter of the branch of port 1.
  • the pump optical signal with wavelength ⁇ 1 is directly transmitted when passing through the optical filter of the port 2-port 64 branch.
  • the MAC unit 910 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the reflected optical signal of the pump optical signal with wavelength ⁇ 1 produces a cross-gain modulation effect or cross-attenuation on the uplink optical signal of ONT1. modulation effect.
  • the optical module 930 measures the received power of the uplink optical signals received from time slot 1 to time slot 64 respectively.
  • the MAC unit 910 compares the received power difference between the received power of the uplink optical signal measured in each time slot and the uplink baseline received power of the optical terminal corresponding to the time slot.
  • the MAC unit 910 compares the received power difference of each time slot with the set threshold.
  • the MAC unit 910 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is greater than or is equal to the set threshold.
  • the MAC unit 910 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal corresponding to the received power difference, that is, there is a binding relationship.
  • the MAC unit 910 controls the wavelength-tunable laser 920 to send a pump optical signal of wavelength ⁇ 2, and continues to determine the optical terminal connected to port 2 corresponding to wavelength ⁇ 2. And so on.
  • the optical filters deployed on the branches of the optical splitter are all transmission filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of transmitting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of reflecting the optical signal of the first wavelength.
  • the optical filter in the connecting branch between the optical splitter and the first optical terminal performs a transmission operation for the pump optical signal of the first wavelength, thereby transmitting the pump optical signal of the first wavelength, thereby Only the pump optical signal of the first wavelength produces a cross-modulation effect on the uplink optical signal of the first optical terminal in the gain component, and no reflected optical signal produces a cross-modulation effect on the uplink optical signal. Therefore, the uplink optical signal received on the time slot corresponding to the first optical terminal has a smaller power change amplitude due to the pump optical signal. Because the optical filter on the branch corresponding to the port of the optical splitter connected to other optical terminals will reflect the pump optical signal of the first wavelength.
  • the pump optical signal of the first wavelength and the reflected optical signal of the pump optical signal produce a cross-modulation effect on the uplink optical signals of other optical terminals. Therefore, the uplink optical signals received in the time slots corresponding to other optical terminals cause a larger power change amplitude of the uplink optical signals due to the pump optical signal and the reflected optical signal.
  • the received power of the uplink optical signal of the first optical terminal changes less than the baseline received power, that is, it is determined that the received power of the uplink optical signal detected in the first time slot is compared with that of the optical terminal corresponding to the first time slot.
  • the change amplitude of the baseline received power is small, and the received power of the uplink optical signal detected in other time slots has a larger change amplitude than the baseline received power of the optical terminal corresponding to other time slots, thereby determining the first optical signal corresponding to the first time slot.
  • the method for determining the topology of the optical access network will be described in conjunction with FIG. 9 .
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT, and they are all transmission filters.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 920 is adjusted to the wavelength ⁇ 1 and continuously emits a pump light signal of the wavelength ⁇ 1.
  • the pump light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the pump optical signal with the wavelength ⁇ 1 is transmitted through the optical filter of the branch of port 1.
  • the pump optical signal with wavelength ⁇ 1 is reflected back when passing through the optical filter of the port 2-port 64 branch.
  • the MAC unit 910 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the pump optical signal of wavelength ⁇ 1 produces a cross-gain modulation effect on the uplink optical signal of ONT1 Or cross-attenuation modulation effects. This makes the power of the uplink optical signal of ONT1 change less than the baseline received power of ONT1.
  • the pump optical signal of wavelength ⁇ 1 and the pump optical signal When it is the turn of any ONT in ONT2-ONT64 connected to port 2-port 64 to send an uplink optical signal, the pump optical signal of wavelength ⁇ 1 and the pump optical signal When the reflected optical signal of the gain component meets the upstream optical signal of any ONT in ONT2-ONT64, the pump optical signal with wavelength ⁇ 1 will produce a cross-gain modulation effect or cross-over on the upstream optical signal of any ONT in ONT2-ONT64. Attenuating modulation effects. This causes the received power of the uplink optical signal of any ONT among ONT2-ONT64 to change significantly compared with the baseline received power of any ONT.
  • the optical module 930 measures the received power of the uplink optical signals received from time slot 1 to time slot 64 respectively.
  • the MAC unit 910 compares the received power difference between the received power of the uplink optical signal measured in each time slot and the uplink baseline received power of the optical terminal corresponding to the time slot.
  • the MAC unit 910 compares the received power difference of each time slot with the set threshold.
  • the MAC unit 910 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is less than the set threshold, and the MAC unit 910 determines that the difference in the received power of the uplink optical signal received in time slot 2 to time slot 64 is less than the set threshold.
  • the difference between the received power of the optical signal and the uplink baseline received power of the optical terminal corresponding to the corresponding time slot is greater than or equal to the set threshold.
  • the MAC unit 910 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal corresponding to the received power difference, that is, there is a binding relationship.
  • the deployment position relationship between the gain component and the optical filter is as shown in Figure 3B.
  • the optical filters deployed on the branches of the optical splitter are all reflective filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of reflecting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of transmitting optical signals of the first wavelength.
  • the optical filter in the connecting branch between the optical splitter and the first optical terminal will perform a reflection operation on the pump optical signal of the first wavelength, thereby reflecting the pump optical signal of the first wavelength back, thereby
  • the pump optical signal of the first wavelength will not reach the gain component, and will not produce a cross-modulation effect on the uplink optical signal of the first optical terminal in the gain component.
  • the optical filter on the branch corresponding to the port of the optical splitter connected to the other optical terminals will not reflect the pump optical signal of the first wavelength, but directly transmits it through the gain component. Therefore, the pump optical signal of the first wavelength produces a cross-modulation effect on the uplink optical signals of other optical terminals in the gain component.
  • the uplink optical signal received in the time slot corresponding to other optical terminals causes the power change of the uplink optical signal due to the pump optical signal.
  • the pump optical signal of the first wavelength will not produce a cross-modulation effect on the uplink optical signal of the first optical terminal in the gain component, so the received power of the uplink optical signal of the first optical terminal will not change.
  • the received power of the uplink optical signal of the first optical terminal has not changed compared to the baseline received power, while the received power of the uplink optical signals of other optical terminals has changed compared to the baseline received power, that is, it is determined that the first time
  • the received power of the uplink optical signal detected in the slot has not changed compared with the baseline received power of the optical terminal corresponding to the first time slot to determine the branch of the first optical terminal corresponding to the first time slot and the optical splitter corresponding to the first wavelength.
  • the method for determining the topology of the optical access network will be described in conjunction with the determining device provided in FIG. 9 .
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT, and they are all reflective filters.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 920 is adjusted to the wavelength ⁇ 1 and continuously emits a pump light signal of the wavelength ⁇ 1.
  • the pump light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the pump optical signal of wavelength ⁇ 1 passes through the branch of port 1. When the light is filtered, it is reflected back and will not reach the gain component of port 1.
  • the pump optical signal with wavelength ⁇ 1 passes through the optical filter of the branch from port 2 to port 64, it is transmitted out and reaches the gain component of the branch from port 2 to port 64.
  • the MAC unit 910 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the pump optical signal of wavelength ⁇ 1 will not pass through the gain component, that is, there will be no cross-gain modulation effect or cross-attenuation on the uplink optical signal of ONT1. modulation effect.
  • the power of the uplink optical signal of ONT1 does not change compared with the baseline received power of ONT1.
  • the pump optical signal with wavelength ⁇ 1 When it is the turn of any one of ONT2-ONT64 connected from port 2 to port 64 to send an uplink optical signal, the pump optical signal with wavelength ⁇ 1 will pass through the optical filter and will be connected to any one of ONT2-ONT64 in the gain component.
  • the pump optical signal with wavelength ⁇ 1 produces a cross-gain modulation effect or a cross-attenuation modulation effect on the upstream optical signal of any ONT in ONT2-ONT64. This causes the received power of the uplink optical signal of any ONT among ONT2-ONT64 to change compared to the baseline received power of any ONT.
  • the optical module 930 measures the received power of the uplink optical signals received from time slot 1 to time slot 64 respectively.
  • the MAC unit 910 compares the received power difference between the received power of the uplink optical signal measured in each time slot and the uplink baseline received power of the optical terminal corresponding to the time slot.
  • the MAC unit 910 compares the received power difference of each time slot with the set threshold.
  • the MAC unit 910 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is less than the set threshold (approximately 0), and the MAC unit 910 determines that time slot 2-time The difference between the received power of the uplink optical signal received in slot 64 and the uplink baseline received power of the optical terminal corresponding to the corresponding time slot is greater than or equal to the set threshold. Further, the MAC unit 910 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal whose received power difference is less than the set threshold, that is, there is a binding relationship.
  • the optical filters deployed on the branches of the optical splitter are all reflective filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of reflecting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of transmitting optical signals of the first wavelength.
  • the optical filter in the connecting branch between the optical splitter and other optical terminals will perform a reflection operation on the pump optical signal of the first wavelength, thereby reflecting the pump optical signal of the first wavelength back, so that the first wavelength of the pump optical signal is reflected back.
  • the pump optical signal of one wavelength will not reach the gain component, and will not produce a cross-modulation effect on the upstream optical signals of other optical terminals in the gain component.
  • the pump optical signal of the first wavelength will not produce a cross-modulation effect on the uplink optical signals of other optical terminals in the gain component, so the received power of the uplink optical signals of other optical terminals will not change.
  • the optical filter on the branch corresponding to the port of the optical splitter connected to the first optical terminal will not reflect the pump optical signal of the first wavelength, but directly transmits it through the gain component. Therefore, the pump optical signal of the first wavelength produces a cross-modulation effect in the gain component on the uplink optical signal of the first optical terminal.
  • the uplink optical signal received on the first time slot corresponding to the first optical terminal causes a power change of the uplink optical signal due to the pump optical signal.
  • the received power of the uplink optical signal of the first optical terminal has changed compared to the baseline received power, while the received power of the uplink optical signals of other optical terminals has not changed compared to the baseline received power, that is, it is determined that the first time
  • the received power of the uplink optical signal detected in the slot changes compared with the baseline received power of the optical terminal corresponding to the first time slot to determine the branch of the first optical terminal corresponding to the first time slot and the optical splitter corresponding to the first wavelength.
  • the optical interface provided by the embodiment of the present application is evaluated in conjunction with the determining device provided in Figure 9.
  • the method for determining the network topology is explained.
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT, and they are all transmission filters.
  • Gain components are also deployed on each branch of the optical splitter connected to the ONT.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 920 is adjusted to the wavelength ⁇ 1 and continuously emits a pump light signal of the wavelength ⁇ 1.
  • the pump light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the pump optical signal of wavelength ⁇ 1 passes through the optical filter of the branch of port 1, it is transmitted and reaches the gain component of port 1.
  • the pump optical signal with wavelength ⁇ 1 passes through the optical filter of the branch from port 2 to port 64, it is reflected back and will not reach the gain component of the branch from port 2 to port 64.
  • the MAC unit 910 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the pump optical signal of wavelength ⁇ 1 will pass through the gain component, which will produce a cross-gain modulation effect or a cross-attenuation modulation effect on the uplink optical signal of ONT1. . This causes the power of the uplink optical signal of ONT1 to change compared to the baseline received power of ONT1.
  • the pump optical signal with wavelength ⁇ 1 is reflected back through the optical filter and does not reach the gain component, and thus does not interact with the gain component within the gain component.
  • the pump optical signal with wavelength ⁇ 1 will not produce a cross-gain modulation effect or cross-attenuation modulation effect on the upstream optical signal of any ONT in ONT2-ONT64. This prevents the received power of the uplink optical signal of any ONT from ONT2 to ONT64 from changing.
  • the optical module 930 measures the received power of the uplink optical signals received from time slot 1 to time slot 64 respectively.
  • the MAC unit 910 compares the received power difference between the received power of the uplink optical signal measured in each time slot and the uplink baseline received power of the optical terminal corresponding to the time slot.
  • the MAC unit 910 compares the received power difference of each time slot with the set threshold.
  • the MAC unit 910 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is greater than or equal to the set threshold, and the MAC unit 910 determines that time slot 2-time slot 64 The difference between the received power of the received uplink optical signal and the uplink baseline received power of the optical terminal corresponding to the corresponding time slot is less than the set threshold ((approximately 0)). Further, the MAC unit 910 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal whose received power difference is greater than or equal to the set threshold, that is, there is a binding relationship.
  • the third possible implementation is described below.
  • Figure 11 is a schematic flow chart of a method for determining the topology of an optical access network in the third possible implementation manner.
  • N optical terminals are optically connected in a one-to-one correspondence with N ports included in multiple optical splitters in the optical access network.
  • N is a positive integer.
  • the ODN in the optical access network uses a first-level optical splitter, and the first-level optical splitter includes at least N ports, and N optical terminals are optically connected to N ports among at least N ports in a one-to-one correspondence.
  • the ODN in the optical access network uses multi-level optical splitters, such as two-level, three-level, etc.
  • Multiple final optical splitters in ODN include at least N ports. For example, if there are three final-stage optical splitters, the total number of ports of the three final-stage optical splitters is greater than or equal to N, and N optical terminals are optically connected to the N ports of the three final-stage optical splitters in one-to-one correspondence.
  • the method for determining the optical access network topology provided in Figure 11 specifically includes the following steps:
  • the first wavelength corresponds to the first port of the optical splitter, and different ports of the optical splitter correspond to different wavelengths.
  • the optical splitter here can refer to the last-level optical splitter, the upper-level optical splitter, or the first-level optical splitter. This application There is no specific limit on this. Taking a two-stage optical splitter as an example, the first wavelength may correspond to port 1 of the first-stage optical splitter or to port 1 of the second-stage optical splitter.
  • the DBA method can be used to allocate the uplink light-emitting time slot to each optical terminal, or the static bandwidth allocation method can be used to allocate the uplink light-emitting time slot (referred to as the time slot) to each optical terminal.
  • the pump light signal modulation has setting information.
  • the setting information may be frequency setting information or code pattern setting.
  • the pump optical signal after the pump optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has a function of reflecting the detection optical signal of the first wavelength. Function, the optical filter reflects the pump light signal of this wavelength back.
  • the optical filters deployed on the branches of other optical splitters at the same level transmit the detection light signals of the first wavelength.
  • the pump optical signal after the pump optical signal reaches the ODN, it passes through an optical filter deployed on a branch of a certain optical splitter.
  • the optical filter on the branch of the splitter has the ability to transmit the pump light of the first wavelength.
  • the function of the signal is that the optical filter transmits the detection light signal of this wavelength.
  • the optical filters deployed on the branches of other optical splitters at the same stage reflect back the pump optical signals of the first wavelength.
  • the measured change in the received power of an optical terminal compared to the uplink baseline received power of the one optical terminal is the difference between the pump optical signal and the uplink optical signal of the one optical terminal between the optical splitter and the first It is caused by the cross-gain modulation effect or cross-attenuation modulation effect in the connection branch of the optical terminal.
  • the received setting information of the upstream optical signal of an optical terminal is: the pump optical signal generates a cross gain for the upstream optical signal of the optical terminal in the connecting branch between the optical splitter and the first optical terminal.
  • the modulation effect or cross-attenuation modulation effect is caused by modulating the setting information carried by the pump optical signal to the uplink optical signal of the optical terminal.
  • Determining the optical terminal connected to the first port corresponding to the first wavelength according to the detection result can be implemented in any of the following ways:
  • Method 1 The difference between the power of the uplink optical signal received in the first time slot and the uplink baseline received power of the first optical terminal corresponding to the first time slot is greater than or equal to the set threshold and is received in other time slots. When the difference between the power of the uplink optical signal and the uplink baseline received power of the optical terminal corresponding to other time slots is less than the set threshold, it is determined that the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • Method 2 When the uplink optical signal received in the first time slot detects the setting information, it is determined that the first optical terminal corresponding to the first time slot is optically connected to the first port corresponding to the first wavelength.
  • Method 3 In multiple time slots corresponding to multiple optical terminals, the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is less than the set threshold. , and when the setting information is detected in the uplink optical signal received in the first time slot, determine the first optical terminal corresponding to the first time slot and the first port corresponding to the first wavelength. Optical connection.
  • Mode 4 In multiple time slots corresponding to multiple optical terminals, the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot is greater than the set threshold, And when the setting information is detected in the uplink optical signal received in the first time slot, it is determined that the first optical terminal corresponding to the first time slot and the first optical port corresponding to the first wavelength are connect.
  • the difference between the power of the uplink optical signal received in each time slot and the uplink baseline received power of the optical terminal corresponding to each time slot satisfies the above formula (1) and formula (2) condition.
  • the third possible way is similar to the optical path transmission principle in the second possible way, and will not be described again here. It can be understood that when the pump optical signal reaches the gain component and produces a cross-modulation effect on the uplink optical signal of a certain optical terminal, the setting information in the pump optical signal is modulated into the uplink optical signal of the optical terminal. If no cross-modulation effect occurs, it will not be modulated into the uplink optical signal of the optical terminal. Therefore, the binding relationship between the optical terminal and the branch port of the optical splitter can be determined based on the detection of the setting information.
  • calibration of the uplink baseline received power of each optical terminal is performed before continuously sending the pump optical signal of the first wavelength. For details, please refer to the relevant description in the second possible implementation, which will not be described again here. .
  • the method for determining the optical access network topology provided in Figure 11 can be implemented by a device for determining the optical access network topology.
  • the device can be deployed at the optical head end, such as in an OLT.
  • the device includes a MAC unit 1210 and a TL 1220 and a signal detector 1230.
  • the MAC unit 1210 can use FPGA, ASIC, SoC, CPU, NP, DSP, MCU, PLD or other integrated chips.
  • the wavelength-tunable laser 1220 can emit pump light signals of multiple wavelengths.
  • the OLT can control the wavelength-tunable laser 1220 to emit pump optical signals of multiple wavelengths.
  • the pump light signal is the wavelength of the pump light signal reflected by the optical filter provided on each branch.
  • the signal detector can be an optical module 1230 or a receiver.
  • the signal detector has the detection function of Received Signal Strength Indicator (RSSI) and the related detection function of setting frequency or setting code pattern.
  • RSSI Received Signal Strength Indicator
  • the signal detector is the optical module 1230 as an example.
  • the MAC unit 1210, TL1220 and optical module 1230 can be integrated into one chip, or can be implemented through different chips.
  • the MAC unit 1210 controls multiple optical terminals to send uplink optical signals on the time slot corresponding to each optical terminal.
  • the wavelength-tunable laser 1220 continuously sends a pump light signal of a first wavelength to the optical splitter, and the pump light signal of the first wavelength is modulated with setting information.
  • Optical module 1230 used to measure the received power of uplink optical signals received on the time slots corresponding to the multiple optical terminals, and the uplink optical signals received from the time slots corresponding to the multiple optical terminals. Detect specific information to get detection results.
  • the MAC unit 1210 determines, according to the detection result, the optical terminal connected to the first port corresponding to the first wavelength.
  • the deployment position relationship between the gain component and the optical filter is as shown in Figure 3B.
  • the optical filters deployed on the branches of the optical splitter are all reflective filters.
  • the optical terminal connected to the first port is the first optical terminal.
  • the time slot corresponding to the first optical terminal is the first time slot.
  • the optical filter deployed on the branch of the optical splitter connected to the first optical terminal has the function of reflecting the optical signal of the first wavelength.
  • the optical filters deployed in the branches of the optical splitters connected to other optical terminals all have the function of transmitting optical signals of the first wavelength.
  • the optical access network includes 64 ONTs, namely ONT1-ONT64, as an example.
  • ONT1-ONT64 are connected to the ports of different optical splitters respectively.
  • the signal detector 1230 is an optical module 1230 as an example.
  • Optical filters are deployed on each branch of the optical splitter connected to the ONT, and they are all reflective filters.
  • the optical splitter connects each ONT Gain components are also deployed on each branch.
  • a gain component refers to a component that causes two optical signals to produce a cross-gain modulation effect or a cross-attenuation modulation effect.
  • the gain component may be a semiconductor optical amplifier or a doped optical fiber.
  • Different optical filters are used to reflect optical signals of different wavelengths or combinations of wavelengths.
  • the ports of the optical splitter connected to ONT1-ONT64 are port 1-port 64.
  • the wavelengths corresponding to the optical filters of the branches from port 1 to port 64 are ⁇ 1- ⁇ 64 respectively.
  • the wavelength-tunable laser 1220 is adjusted to the wavelength ⁇ 1 and continuously emits a pump light signal of the wavelength ⁇ 1.
  • the pump light signal of wavelength ⁇ 1 is broadcast to each branch of the optical splitter respectively.
  • the pump optical signal of wavelength ⁇ 1 passes through the optical filter of the branch of port 1, it is reflected back and does not reach the gain component of port 1.
  • the pump optical signal with wavelength ⁇ 1 passes through the optical filter of the branch from port 2 to port 64, it is transmitted out and reaches the gain component of the branch from port 2 to port 64.
  • the MAC unit 1210 takes turns controlling all online ONTs to send uplink optical signals in specific time slots. Different ONTs correspond to different time slots, and the time slots corresponding to ONT1-ONT64 are time slot 1-time slot 64 respectively.
  • the pump optical signal of wavelength ⁇ 1 will not pass through the gain component, that is, there will be no cross-gain modulation effect or cross-attenuation on the uplink optical signal of ONT1. modulation effect. This ensures that the power of the uplink optical signal of ONT1 does not change compared to the baseline received power of ONT1, and no setting information is modulated in the uplink optical signal.
  • the pump optical signal with wavelength ⁇ 1 When it is the turn of any ONT among ONT2-ONT64 connected from port 2 to port 64 to send an uplink optical signal, the pump optical signal with wavelength ⁇ 1 will pass through the optical filter and will be connected to any one of ONT2-ONT64 in the gain component.
  • the pump optical signal with wavelength ⁇ 1 produces a cross-gain modulation effect or a cross-attenuation modulation effect on the upstream optical signal of any ONT in ONT2-ONT64.
  • the received power of the uplink optical signal of any ONT among ONT2-ONT64 is changed compared with the baseline received power of any ONT, and the uplink optical signal of any ONT among ONT2-ONT64 is modulated with setting information.
  • the optical module 1230 measures the received power of the uplink optical signals received from time slot 1 to time slot 64 respectively and the uplink optical signal detection setting information received from time slot 1 to time slot 64 respectively.
  • the MAC unit 1210 compares the received power difference between the received power of the uplink optical signal measured in each time slot and the uplink baseline received power of the optical terminal corresponding to the time slot.
  • the MAC unit 1210 obtains the comparison result between the received power difference value of each time slot and the set threshold and/or the time slot in which the uplink optical signal including the setting information is located.
  • the MAC unit 1210 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is less than the set threshold (approximately 0), and the MAC unit 1210 determines that the difference in time slot 2 - The difference between the received power of the uplink optical signal received in time slot 64 and the uplink baseline received power of the optical terminal corresponding to the corresponding time slot is greater than or equal to the set threshold. Further, the MAC unit 1210 determines that port 1 corresponding to wavelength 1 is connected to ONT1 based on the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal corresponding to the received power difference, that is, there is a binding relationship.
  • the MAC unit 1210 determines that no setting information is detected in the uplink optical signal received from time slot 1, but setting information is detected in all uplink optical signals received from other time slots. Further, the MAC unit 1210 determines that port 1 corresponding to wavelength 1 is connected to ONT1 according to the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal corresponding to time slot 1.
  • the MAC unit 1210 determines that the difference between the received power of the uplink optical signal received in time slot 1 and the uplink baseline received power of the optical terminal corresponding to time slot 1 is less than the set threshold (approximately 0), and the MAC unit 1210 determines the time slot 2-The difference between the received power of the uplink optical signal received in time slot 64 and the uplink baseline received power of the optical terminal corresponding to the corresponding time slot is greater than or equal to the set threshold, and the uplink optical signal received from time slot 1 is not detected The setting information is detected, and the setting information is detected in the uplink optical signals received from other time slots. According to the wavelength ⁇ 1 of the wavelength-tunable laser and the optical terminal corresponding to time slot 1, it is determined that port 1 corresponding to wavelength 1 is connected to ONT1.
  • the MAC unit 1210 controls the wavelength-tunable laser 1220 to send a pump optical signal of wavelength ⁇ 2, and continues to determine the optical terminal connected to port 2 corresponding to wavelength ⁇ 2. And so on.
  • One embodiment of the present application provides a computer-readable medium for storing a computer program.
  • the computer program includes instructions for executing the method steps in the method embodiment corresponding to FIG. 4 .
  • embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment that combines software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) having computer-usable program code embodied therein.
  • a computer-usable storage media including, but not limited to, disk storage, optical storage, etc.

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Abstract

一种光接入网拓扑的确定方法、装置及系统，无需对光终端进行改造，可以降低实现复杂度，并且减少人工改造导致的资源浪费。本申请利用不同的ONT在不同时隙发送光信号的原理，分光器中不同的支路对应不同的波长，通过OLT发送不同波长的探测光信号，从而在不同的时隙来监测接收的光信号的变化情况，从而确定发生变化的时隙对应的光终端与波长对应的分光器支路的端口的绑定关系。本申请主要利用探测光信号与光终端的上行光信号在分光器的支路内产生的交叉调制效应，来使得OLT接收到的光信号中产生变化。

Description

一种光接入网拓扑的确定方法、装置及系统
本申请要求于2022年9月6日提交中国国家知识产权局、申请号202211086278.6、申请名称为“一种光接入网拓扑的确定方法、装置及系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光通信技术领域，特别涉及一种光接入网拓扑的确定方法、装置及系统。
背景技术
无源光网络(passive optical network，PON)系统包括光线路终端(optical line terminal，OLT)、光分配网络(optical distribution network，ODN)以及多个位于用户侧的光终端，比如光网络单元(optical network unit，ONU)或光网络终端(optical network termination，ONT)。
PON系统上、下行的光信号可以在同一根光纤中传输。下行方向(自OLT到光终端)的光信号以时分复用(time division multiplexing，TDM)方式工作，OLT发送的数据会广播到所有分支光纤，到达所有的光终端。上行方向(光终端到OLT)的光信号以时分多址(time division multiple access，TDMA)方式工作，光终端只在授权的时隙进行发送。
ODN可以传输OLT和多个光终端之间的光信号。ODN拓扑结构是比较复杂的，比如ODN中包括一级或者多级分光器用来连接OLT与多个光终端，但是光终端与ODN中的分光器的连接关系并非始终不变的，从而给运维人员做故障定位、故障消除带来了困难。
发明内容
本申请实施例提供一种光接入网拓扑的确定方法、装置及系统，无需对ONT改造，从而降低实现的复杂度。
第一方面，本申请实施例提供一种光接入网拓扑的确定方法，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的不同端口一一对应光学连接，所述方法包括：连续发送第一波长的探测光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；在所述多个光终端分别对应的时隙上接收的光信号中检测所述探测光信号的反射光信号的功率；根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端；其中，在接收的光信号中检测到的探测光信号的反射光信号的功率变化是：一个光终端的上行光信号对所述探测光信号以及在所述分光器与所述一个光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路内产生交叉增益调制效应或 者交叉衰减调制效应产生的。
ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器，即在分光器的支路光纤上部署反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的探测光信号，光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，ONT的上行光信号对探测光信号的反射光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得光头端检测到探测光信号的反射光信号的功率相比探测光信号的功率产生变化(比如，增强或者减弱)。由于不同的光滤波器对应不同的波长或者波长组合，能够反射或者透射不同的波长或者波长组合的光信号。不同波长的光滤波器对应不同的端口，进而光头端可以根据探测光信号的波长以及发生功率变化的时间来实现分光器的端口与ONT的绑定。无需对ONT进行改造，可以降低复杂度。
上述两个设备之间光学连接，可用于实现两个设备相互间的光信号的传输。光学连接可以是通过光纤、光波导或者其它光介质来连接。
在一种可能的设计中，根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端，包括：
确定在接收的光信号中检测到的反射光信号的功率发生变化的时间窗口位于第一时隙时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
第二方面，本申请实施例提供一种光接入网拓扑的确定装置，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、波长可调激光器、光电探测器以及环形器，所述环形器的第一端口与所述波长可调激光器光学连接，所述环形器的第二端口与所述分光器光学连接，所述环形器的第三端口与所述光电探测器光学连接；
所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
所述波长可调激光器，用于通过环形器向所述分光器连续发送第一波长的探测光信号；
所述光电探测器，用于在所述多个光终端分别对应的时隙上通过所述环形器接收的光信号中检测所述探测光信号的反射光信号的功率；
所述MAC单元，还用于根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端；
其中，在接收的光信号中检测到探测光信号的反射光信号的功率发生变化是：一个光终端的上行光信号对所述探测光信号以及在所述分光器与所述一个光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
在一种可能的设计中，所述MAC单元，具体用于：
确定所述反射光信号的功率发生变化的时间窗口位于第一时隙时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
第三方面，本申请实施例提供另一种光接入网拓扑的确定方法，所述光接入网包括多个 光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述方法包括：连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率；根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端；其中，一个光终端的上行基线接收功率为所述泵浦光信号未进入所述分光器与所述一个光终端之间的光纤情况下所述一个光终端的上行光信号的接收功率；一个光终端的接收功率与所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的泵浦光信号，光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，探测光信号对上行光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得光终端的上行光信号的功率产生变化(比如，增强或者减弱)。由于不同的光滤波器对应不同的波长或者波长组合，能够反射或者透射不同的波长或者波长组合的光信号。不同波长的光滤波器对应不同的端口，进而光头端可以根据探测光信号的波长以及发生功率变化上行光信号的时隙来实现分光器的端口与ONT的绑定。
在一种可能的设计中，所述根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端，包括：
在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差小于设定阈值，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差小于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差均大于或者等于设定阈值，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在一种可能的设计中，所述泵浦光信号是经过设定信息的调制得到的，所述根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端，包括：
在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均小于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均大于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在一种可能的设计中，所述设定信息包括设定频率和/或设定码型。
在一种可能的设计中，所述方法还包括：
在连续发送第一波长的泵浦光信号之前，控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号，并测量所述多个光终端的上行光信号的接收功率以得到所述多个光终端中每个光终端的上行基线接收功率。
第四方面，本申请实施例提供一种光接入网拓扑的确定装置，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、光模块以及波长可调激光器；
所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
所述波长可调激光器，用于连续发送第一波长的探测光信号；
所述光模块，用于测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率；
所述MAC单元，根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端；
其中，一个光终端的上行基线接收功率为所述泵浦光信号未进入所述分光器与所述一个光终端之间的光纤情况下所述一个光终端的上行光信号的接收功率；一个光终端的接收功率与所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
在一种可能的设计中，所述MAC单元，具体用于：
在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差小于设定阈值时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差小于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差均大于或者等于设定阈值时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在一种可能的设计中，所述泵浦光信号是经过设定信息的调制得到的，所述光模块，还用于从多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息；
所述MAC单元，具体用于：
在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均小于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均大于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述 第一端口光学连接。
在一种可能的设计中，所述设定信息包括设定频率和/或设定码型。
在一种可能的设计中，所述MAC单元，还用于在连续发送第一波长的泵浦光信号之前，控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
所述光模块，还用于测量所述多个光终端的上行光信号的接收功率以得到所述多个光终端中每个光终端的上行基线接收功率。
第五方面，本申请实施例提供一种光接入网拓扑的确定方法，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述方法包括：
连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；所述泵浦光信号是经过设定信息的调制得到的；
在所述多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息得到每个时隙的检测结果；
根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的泵浦光信号。泵浦光信号可以通过设定信息调制得到的。比如经过设定频率的频率调制得到的，或者经过设定码型的码型调制得到的。设定频率，比如可以是正率波，当然也可以采用其它的频率。设定码型，比如可以是扩频码。光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，探测光信号对上行光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得泵浦光信号中的设定频率信息或者设定码型信息被调制到光终端的上行光信号上，进而可以基于检测到设定频率信息或者设定码型信息的上行光信号所在的时隙与泵浦光信号的波长来实现分光器的端口与ONT的绑定。无需对ONT进行改造，可以降低复杂度。
在一种可能的设计中，根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端，包括：
在第一时隙内接收到的上行光信号检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号未检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在第一时隙内接收到的上行光信号未检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号检测到设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在一种可能的设计中，所述设定信息包括设定频率和/或设定码型。
第六方面，本申请实施例提供一种光接入网拓扑的确定装置，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、光模块以及波长可调激光器；
所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
所述波长可调激光器，用于连续发送第一波长且调制有设定信息的探测光信号；
所述光模块，用于在所述多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息得到每个时隙的检测结果；
所述MAC单元，根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
在一种可能的设计中，所述MAC单元，具体用于：
在第一时隙内接收到的上行光信号检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号未检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
在第一时隙内接收到的上行光信号未检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号检测到设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在一种可能的设计中，所述设定信息包括设定频率和/或设定码型。
第七方面，本申请实施例提供一种光接入网拓扑的确定系统，包括第二方面所述的装置或者第四方面所述的装置或者第六方面所述的装置，所述系统还包括光分配网络ODN和多个光终端，所述ODN与多个光终端光学连接，所述ODN中包括一个分光器或者多个分光器；
所述ODN中分光器与所述多个光终端中每个光终端的连接支路内部署有光滤波器，其中，不同连接支路上光滤波器对应不同的波长，用于对不同波长的光信号进行反射或者透射。
在一种可能的设计中，所述ODN中分光器与多个光终端中每个光终端的连接支路内还部署增益组件，所述增益组件位于所述分光器分支端与所述光滤波器之间，或者所述增益组件位于所述光滤波器与所述光终端之间；
所述增益组件支持对同时接收到的多个光信号产生交叉增益调制效应或者交叉衰减效应。
在一种可能的设计中，所述光滤波器为布拉格光栅FBG。
本申请在上述各方面提供的实现的基础上，还可以进行进一步组合以提供更多实现。
附图说明
为了更清楚地说明本申请实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简要介绍。
图1为本申请实施例提供的一种系统架构示意图；
图2为对系统改造后的系统结构示意图；
图3A为本申请实施例提供的一种增益组件部署位置示意图；
图3B为本申请实施例提供的另一种增益组件部署位置示意图；
图4为本申请实施例的第一种可能的实现方式描述的光接入网络拓扑的确定方法流程示意图；
图5A为本申请实施例的第一种可能的实现方式中一种探测光信号功率变化情况示意图；
图5B为本申请实施例的第一种可能的实现方式中另一种探测光信号功率变化情况示意图；
图6为本申请实施例的第一种可能的实现方式中光接入网络拓扑的确定装置；
图7A为本申请实施例的示例一提供的光接入网络拓扑的确定示意图；
图7B为本申请实施例的示例二提供的光接入网络拓扑的确定示意图；
图8为本申请实施例的第二种可能的实现方式描述的光接入网络拓扑的确定方法流程示意图；
图9为本申请实施例的第二种可能的实现方式中光接入网络拓扑的确定装置；
图10A为本申请实施例的示例三提供的一种光接入网络拓扑的确定示意图；
图10B为本申请实施例的示例三提供的另一种光接入网络拓扑的确定示意图；
图10C为本申请实施例的示例四提供的一种光接入网络拓扑的确定示意图；
图10D为本申请实施例的示例四提供的另一种光接入网络拓扑的确定示意图；
图10E为本申请实施例的示例五提供的一种光接入网络拓扑的确定示意图；
图10F为本申请实施例的示例五提供的另一种光接入网络拓扑的确定示意图；
图10G为本申请实施例的示例六提供的一种光接入网络拓扑的确定示意图；
图10H为本申请实施例的示例六提供的另一种光接入网络拓扑的确定示意图；
图11为本申请实施例的第三种可能的实现方式描述的光接入网络拓扑的确定方法流程示意图；
图12为本申请实施例的第三种可能的实现方式中光接入网络拓扑的确定装置；
图13为本申请实施例的示例七提供的一种光接入网络拓扑的确定示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。
其中，在本申请的描述中，除非另有说明，“多个”是指两个或多于两个。另外，“/”表示前后关联的对象是一种“或”的关系，例如，A/B可以表示A或B；本申请中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况，其中A,B可以是单数或者复数。并且，为了便于清楚描述本申请实施例的技术方案，在本申请的实施例中，采用了“第一”、“第二”等字样对功能和作用基本相同的相同项或相似项进行区分。本领域技术人员可以理解“第一”、“第二”等字样并不对数量和执行次序进行限定，并且“第一”、“第二”等字样也并不限定一定不同。还需要说明的是，除非特殊说明，一个实施例中针对一些技术特征的具体描述也可以应用于解释其他实施例提及对应的技术特征。
在本申请实施例中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请实施例中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其它实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念。
参见图1所示为本申请实施例提供的一种系统架构示意图。所述系统可以为无源光网络PON系统100。PON系统100可以应用于光接入网。PON系统100包括至少一个光线路终端OLT110一个光分配网络ODN120和多个光终端。图1中以光终端为ONT为例。本申请中OLT110通过ODN120连接到多个ONT130。其中，从OLT110到ONT130的方向定义为下行方向，而从ONT130到OLT110的方向为上行方向。
所述PON系统100可以是不需要任何有源器件来实现OLT110与ONT130之间的数据分发的通信网络。比如，在具体实施例中，OLT110与ONT130之间的数据分发可以通过ODN120 中的无源光器件(比如分光器)来实现。并且，所述PON系统100可以为异步传输模式无源光网络(asynchronous transfer mode passive optical network，ATM PON)系统或宽带无源光网络(broadband passive optical network，BPON)系统、吉比特无源光网络(gigabit passive optical network，GPON)系统、以太网无源光网络(ethernet passive optical network，EPON)、或者下一代无源光网络(next-generation passive optical network，NG PON)，比如10吉比特无源光网络(10gigabit-capable passive optical network，XG-PON)或10吉比特以太网无源光网络(10Gigabit ethernet passive optical network，10GEPON等。
OLT110通常位于中心位置，例如中心局(central office，CO)，其可以统一管理一个或多个ONT130。OLT110可以将接收到的下行数据通过ODN120转发到ONT130，以及转发从ONT130接收到的上行数据。
ONT130可以分布式地设置在用户侧位置(比如用户驻地)。ONT130可以为用于与OLT110和用户进行通信的设备，具体而言，ONT130可以充当OLT110与所述用户之间的。
例如，ONT130可以将从OLT110接收到的下行数据转发到所述用户，以及将从所述用户接收到的数据作为上行数据通过ODN120转发到OLT11 0。应当理解，ONT130一般应用于最终用户，例如光猫等；而ONU可以应用于最终用户，也可以通过其他网络(比如以太网)与最终用户连接。在本申请中，以ONT130为例进行描述，ONT130和ONU之间可以互换。
ODN120可以包括光纤、光耦合器、分光器和/或其他设备。在一个实施例中，所述光纤、光耦合器、分光器和/或其他设备可以是无源光器件。即，所述光纤、光耦合器、分光器和/或其他设备可以是在OLT110和ONT130之间分发数据信号是不需要电源支持的器件。另外，在其他实施例中，ODN120还可以包括一个或多个有源设备，例如，光放大器或者中继设备(Relay device)。在如图1所示的分支结构中，ODN120具体可以采用二级分光的方式从OLT110延伸到多个ONT130，但也可以配置成其他任何点到多点(如一级分光或者多级分光)或者点到点的结构。本申请实施例以二级分光为例进行描述，一级分光、多级分光(三级及以上分光)类似，本申请不对此限定。
参见图1所示，ODN120采用分光器来实现数据分发，出于可靠性和运维方面的考虑，ODN120可以采用两级分光的方式来部署，包括第一级分光器121和多个第二级分光器122。所述第一级分光器121的公共端通过主干光纤连接到OLT110，且其分支端分别通过分布光纤对应地连接到所述第二级分光器122的公共端，每个第二级分光器122的分支端分别进一步通过分支光纤连接到对应的ONT130的上行端口。在下行方向，OLT110发送的下行数据信号先经过第一级分光器121进行第一次分光之后，再分别经过第二级分光器122进行第二次分光，从而形成多路下行光信号并传输给各个ONT130。在上行方向，各个ONT130发送的上行数据信号依次通过第二级分光器122和第一级分光器121进行合路之后传输到OLT110。
其中，对于二级分光的部署方式，第二级分光器122是末级分光器，第一级分光器121是末级分光器连接的前一级分光器；而对于一级分光的部署方式，第一级分光器即为末级分光器；对于三级分光的部署方式，第三级分光器是末级分光器，第二级分光器为末级分光器连接的前一级分光器，第一级分光器为所述第二级分光器连接的前一级分光器。由上所述可知，本申请中末级分光器是指更接近ONT的分光器。
结合图1来，OLT110与多个ONT130之间通过一级或者多级分光器连接，由于连接关系并非始终不变的，因此运维人员做故障定位、故障消除时需要预先知晓OLT110与多个ONT 在ODN中的连接拓扑。目前一种可能的实现方式中，参见图2所示，在分光器中增加反射型或者透射型滤波器、在CO中部署吸收光带(U-band)可调激光器并且在ONT中增加U-band接收机。
通过U-band可调激光器发射不同波长的光信号，然后ONT检测是否收到该波长的光信号，以确定ONT与分光器端口的绑定关系。
比如，ODN中采用反射型滤波器。OLT先控制U-band可调激光器发送波长λ1的光信号，并发报文要求所有ONT上报是否有收到U-band光信号。然后再控制U-band可调激光器发送波长为λ9的光信号，并发报文要求所有的ONT上报是否有收到U-band光信号。基于所有ONT两次上报的数据，如果某一ONT两次都没有收到U-band光信号，则可判定该ONT连接在一级分光器的端口1和二级分光器的端口1上。其中，一级分光器的端口1或者端口1的分支光纤上具有波长λ1的反射型滤波器，用于反射波长λ1的光信号。二级分光器的端口1的分支光纤上具有波长λ9的反射型滤波器，用于反射波长λ1的光信号。不同的分光器的不同端口对应不用的波长的反射型滤波器。依次类推，可以实现对所有ONT与分光器的绑定关系的确定。
再比如，ODN中采用透射型滤波器。OLT先控制U-band可调激光器发送波长λ1的光信号，并发报文要求所有ONT上报是否有收到U-band光信号。然后再控制U-band可调激光器发送波长为λ9的光信号，并发报文要求所有的ONT上报是否有收到U-band光信号。基于所有ONT两次上报的数据，如果某一ONT两次都收到U-band光信号，则可判定该ONT连接在一级分光器的端口1和二级分光器的端口1上。其中，一级分光器的端口1或者端口1的分支光纤上具有透射型滤波器，至少用于透射波长λ1和λ9的光信号。二级分光器的端口1的分支光纤上具有透射型滤波器，至少用于透射波长λ9的光信号。不同的分光器的不同端口对应不用的波长或者波长组合的透射型滤波器。依次类推，可以实现对所有ONT与分光器的绑定关系的确定。
上述方式中，需要针对PON系统中的各个器件都进行改造后才能实现。而光终端的数量较多，改造难度较大，从而增加了实现的复杂度。
基于此，本申请实施例提供一种光接入网拓扑的确定方法、设备及系统。在光终端出现网络连接不上、网络信号差等问题时，运维人员能够根据确定的绑定关系(或者连接关系)快速定位该光终端所连接的端口或者端口对应的光纤链路，为故障定位和故障消除提供了的便利性。并且本申请无需对光终端设备进行改造，可以降低实现复杂度，并且减少人工改造导致的资源浪费。
PON上行传输中，不同ONT的上行数据在各自支路光纤向上传输，经过分光器后数据汇合。上行采用时分复用方式传输数据，上行链路被分成不同的时隙(slot)，每个ONT在哪个时隙发送数据，严格由OLT统一调度和授权，ONT只能被动响应。一种方式中，动态带宽分配。OLT具备动态带宽分配(dynamic bandwidth allocation，DBA)功能。OLT通过DBA模块对PON的拥塞进行实时监控，根据拥塞和当前带宽利用情况，以及配置情况对ONT进行动态的带宽调整。另一种方式中，静态带宽分配(也可以称为固定带宽分配)。每个ONT占用的带宽是固定的，OLT可以根据每个ONT带宽、时延等指标周期性地为每个ONT分配固定时间长度的授权。
本申请实施例中利用不同的ONT在不同时隙发送光信号的原理，分光器中不同的支路对 应不同的波长，通过OLT发送不同波长的探测光信号，从而在不同的时隙来监测接收的光信号的变化情况，从而确定发生变化的时隙对应的光终端与波长对应的分光器支路的端口的绑定关系。本申请实施例主要利用探测光信号与光终端的上行光信号在分光器的支路内产生的交叉调制效应，来使得OLT接收到的光信号中存在变化。
交叉调制，是指通过在非线性的设备、网络或传输煤质中各信号间的相互作用所产生的一个信号对另一个信号的载波的调制。交叉调制可以是交叉增益调制或者交叉衰减调制。
一些实施例中，分光器与ONT的连接支路部署光滤波器以及增益组件。光滤波器可以采用反射型滤波器也可以采用透射型滤波器。例如，光滤波器可以采用光纤布拉格光栅(fiber bragg grating，FBG)。例如，增益组件可以采用光放大器或者其它具有增益调制功能的器件。一些场景中，光滤波器的功能以及增益组件的功能可以集成在一个组件中实现。比如分光器与ONT的连接通道上采用具有反射或者透射功能的FBG掺杂光纤。另一些场景中，光滤波器与增益组件可以由不同组件来实现，光滤波器可以部署于支路光纤上。增益组件可以部署于光滤波器与分光器之间的支路端(也可以称为分支端)光纤上或者部署于分光器的端口上，参见图3A所示。增益组件也可以位于光滤波器与光终端之间，参见图3B所示。
本申请示例性地提供三种可能的方式，来实现在不需要对ONT进行改造的情况，确定光接入网络的拓扑信息。
第一种可能的实现方式：ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器，即在分光器的支路光纤上部署反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的探测光信号，光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，ONT的上行光信号对探测光信号的反射光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得光头端检测到探测光信号的反射光信号的功率相比探测光信号的功率产生变化(比如，增强或者减弱)。由于不同的光滤波器对应不同的波长或者波长组合，能够反射或者透射不同的波长或者波长组合的光信号。不同波长的光滤波器对应不同的端口，进而光头端可以根据探测光信号的波长以及发生功率变化的时间来实现分光器的端口与ONT的绑定。
第二种可能的实现方式中，ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的泵浦光信号，光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，探测光信号对上行光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得光终端的上行光信号的功率产生变化(比如，增强或者减弱)。由于不同的光滤波器对应不同的波长或者波长组合，能够反射或者透射不同的波长或者波长组合的光信号。不同波长的光滤波器对应不同的端口，进而光头端可以根据探测光信号的波长以及发生功率变化上行光信号的时隙来实现分光器的端口与ONT的绑定。
第三种可能的实现方式中，ODN中部署的光滤波器可以是反射型滤波器或者透射型滤波器。在光头端连续发送特定波长的泵浦光信号。泵浦光信号可以通过设定信息调制得到的。比如经过设定频率的频率调制得到的，或者经过设定码型的码型调制得到的。设定频率，比如可以是正率波，当然也可以采用其它的频率。设定码型，比如可以是扩频码。光头端控制光接入网中的多个光终端分别在对应的时隙上发送上行光信号。其中，探测光信号对上行光信号在支路的增益组件内产生交叉增益调制效应或者交叉衰减调制效应，从而使得泵浦光信 号中的设定频率信息或者设定码型信息被调制到光终端的上行光信号上，进而可以基于检测到设定频率信息或者设定码型信息的上行光信号所在的时隙与泵浦光信号的波长来实现分光器的端口与ONT的绑定。
下面结合附图对以上三种可能实现方式进行详细描述。
先对第一种可能的实现方式进行描述。参见图4所示，为第一种可能的实现方式的光接入网络拓扑的确定方法流程示意图。以光接入网中包括N个光终端为例。N个光终端与光接入网中的多个分光器包括的N个端口一一对应光学连接。N为正整数。一些场景中，光接入网中的ODN采用一级分光器，则该一级分光器包括至少N个端口，N个光终端与至少N个端口中的N个端口一一对应光学连接。另一些场景中，光接入网络中的ODN采用多级分光器，比如两级、三级等等。ODN中的多个末级分光器至少包括N个端口。比如，末级分光器为3个，则3个末级分光器的总端口数量大于或者等于N，N个光终端与3个末级分光器的N个端口一一对应光学连接。
图4提供的光接入网络拓扑的确定方法具体包括以下步骤：
401，连续发送第一波长的探测光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号。
所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长。这里的分光器可以是指末级分光器，也可以是上一级分光器，还可以第一级分光器，本申请对此不作具体限定。以两级分光器为例，第一波长可以对应于第一级分光器的端口1或者对应于第二级分光器的端口1。
每个光终端对应的时隙，可以采用DBA方式为每个光终端分配上行发光时隙，也可以采用静态带宽分配方式为每个光终端分配上行发光时隙(简称时隙)。
402，在所述多个光终端分别对应的时隙上接收的光信号中检测所述探测光信号的反射光信号的功率。
一些实施例中，探测光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有反射第一波长的探测光信号的功能，光滤波器将该波长的探测光信号反射回来。同级的其它分光器的支路上部署的光滤波器针对该第一波长的探测光信号均透射出去。
另一些实施例中，探测光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有透射第一波长的探测光信号的功能，光滤波器将该波长的探测光信号透射出去。同级的其它分光器的支路上部署的光滤波器针对该第一波长的探测光信号均反射回来。
403，根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端。
其中，在接收的光信号中检测到探测光信号的反射光信号的功率发生变化是：一个光终端的上行光信号对所述探测光信号以及在所述分光器与所述一个光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
以第一端口所连接的光终端为第一光终端为例。第一光终端对应的时隙为第一时隙。
在根据所述反射光信号的功率发生变化的时间与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端的情况下，可以通过如下方式实现：确定在接收的光信号中检测到的反射光信号的功率发生变化的时间窗口位于第一时隙时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
图4提供的光接入网络拓扑的确定方法可以由光接入网络拓扑的确定装置来实现。该装置可以部署于光头端，比如部署于OLT中。该装置也可以部署于CO中。参见图6所示，该装置包括媒体接入控制(media access control，MAC)单元510、波长可调激光器(tunable laser，TL)520、光电探测器530以及环形器540。环形器540的第一端口与波长可调激光器520光学连接，环形器540的第二端口与ODN光学连接，环形器540的第三端口与光电探测器530光学连接。波长可调激光器也可以称为可调谐激光器(tunable laser，TL)。
MAC单元510可以采用现场可编程门阵列(field-programmable gate array，FPGA)，可以采用专用集成芯片(application specific integrated circuit，ASIC)，还可以采用系统芯片(system on chip，SoC),还可以采用中央处理器(central processor unit，CPU)，还可以采用网络处理器(Network Processor，NP)，还可以采用数字信号处理电路(digital signal processor，DSP)，还可以采用微控制器(micro controller unit，MCU)，还可以采用可编程控制器(programmable logic device，PLD)或其他集成芯片。波长可调激光器520可以发射多种波长的探测光信号。在识别目标ONT(ODN连接的任一ONT)连接的分支支路(支路的端口)时，OLT可以在控制波长可调激光器520可以发出多种波长的探测光信号，多种波长的探测光信号为每个分支支路上设置的光滤波器所反射或者透射的探测光信号的波长。光电探测器530可以探测波长可调激光器520发射的探测光信号通过环形器接收的通过ODN反射回来的激光。
一些实施例中，MAC单元510、波长可调激光器520、光电探测器530以及环形器540均可以集成在一个芯片中，也可以通过不同的芯片来实现。比如，MAC单元510通过一个芯片实现，比如称为MAC芯片。波长可调激光器520、光电探测器530以及环形器540可以集成在一个芯片中，比如称为OAI芯片。一些场景中，MAC单元510部署于OLT中，波长可调激光器520、光电探测器530以及环形器540集成在一个芯片中，部署于OLT之外，并与OLT光学连接。
以确定第一波长对应的分光器的支路的端口所连接的光终端为例。
MAC单元510控制多个光终端分别在每个光终端对应的时隙上发送上行光信号。波长可调激光器520通过环形器540向分光器连续发送第一波长的探测光信号。光电探测器(photoelectric detector，PD)530，可以通过环形器540在各个时隙上接收到的光信号中检测探测光信号的反射光信号的功率。进一步地，MAC单元510根据在接收的光信号中检测到反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端。
如下以增益组件与光滤波器的部署位置关系为图3A所示的位置为例。
示例一：
分光器的支路上部署的光滤波器均为反射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有反射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均 具有透射第一波长的光信号的功能。分光器与第一光终端的连接支路内的光滤波器对于第一波长的探测光信号会执行反射操作，从而将第一波长的探测光信号反射回去。由于其它的光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的探测光信号不会发生反射，而直接透射出去。从而在其它光终端对应的时隙上接收到的光信号中未检测到的反射光信号，即功率不发生波动。
具体的，第一光终端的上行光信号对所述探测光信号在所述连接支路的增益组件上产生交叉增益调制效应或者交叉衰减调制效应，以及针对在所述分光器与所述第一光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路的增益组件上也会产生交叉增益调制效应或者交叉衰减调制效应，使得在第一光终端的时隙上检测到的光信号中的探测光信号被增强或者减弱。而探测光信号在经过其它光终端所连接的分光器的连接支路的光滤波器时，被透射出去，即不会产生探测光信号的反射的光信号，从而其它光终端的上行光信号也不会对反射的光信号的交叉增益调制效应或者交叉衰减调制效应。使得在其它光终端的时隙上未检测到的反射光信号，即反射光信号的功率不会有增强或者减弱(近似为0)。进一步地，可以确定在第一光终端的时隙内接收到的上行光信号中检测到的探测光信号的功率相比在其它的时隙内接收到的上行光信号中检测到的探测光信号的功率发生波动，比如增大或者减少。
例如参见图5A和图5B所示，图5A和图5B中将探测光信号功率表示为POAI，将在接收到光信号中检测到的探测光信号的功率表示为POAI_R。图5A中第一光终端的时隙内接收到的上行光信号中检测到的探测光信号的功率相比在其它的时隙内接收到的上行光信号中检测到的探测光信号的功率发生增强。图5B中表示第一光终端的时隙内接收到的上行光信号中检测到的探测光信号的功率相比在其它的时隙内接收到的上行光信号中检测到的探测光信号的功率发生增强。光终端的上行发射是完全受OLT DBA控制，包括光终端上行光信号的发射开启时间(Ton)、关闭时间(Toff)以及开启持续时间(即光终端占用的时隙)，Tc＝Toff-Ton。
一些实施例中，在确定分光器的第一端口所连接的光终端后，继续确定其它端口所连接的光终端。比如继续发送第二波长的探测光信号，第二波长对应分光器的第二端口，通过图4对应的实施例提供的方式，已确定第二端口所连接的光终端，依次类推，直到确定所有端口所连接的光终端。
作为一种举例，参见图7A所示，光接入网中包括64个ONT，分别为ONT1-ONT64。ONT1-ONT64分别连接不同的分光器的端口。图7A中，以MAC单元510部署于OLT中为例。OLT还有其它组件，比如光模块等，在图7A中未示出。在分光器连接ONT的每个支路上均部署于有光滤波器。分光器连接ONT的每个支路上还部署增益组件。增益组件指使得两个光信号产生交叉增益调制效应或者交叉衰减调制效应的组件。示例性地，增益组件可以是半导体光放大器，也可以是掺杂的光纤。不同的光滤波器均为反射型滤波器，用于反射不同波长的光信号。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器520调整到波长λ1，连续发射波长λ1的探测光信号。该探测光信号的功率为POAI。该波长λ1的探测光信号分别广播到分光器的各个支路上。该波长λ1的探测光信号在经过端口1的支路的光滤波器时，反射回来。波长λ1的探测光信号在经过端口2-端口64的支路的光滤波器时，直接透射出去。
MAC单元510中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，在经过增益组件时，ONT1的上行光信号对波长λ1的探测光信号及波长λ1的探测光信号经过光滤波器反射回来的信号产生交叉增益调制效应或者交叉衰减调制效应。光电探测器530从接收到光信号中检测探测光信号的功率，可以理解为探测光信号的反射光信号的功率。
光电探测器530在时隙1探测到的探测光信号功率相比其它时隙探测到的探测光信号的功率会发送波动(增大或者减小)。例如参见图7A所示。图7A中虚线表示探测光信号的信号流向。光电探测器530可以检测到功率发生波动的时间窗口。进一步地，MAC单元510根据波长可调激光器的波长λ1、功率发生波动的时间窗口以及各个ONT发送上行光信号的时隙来确定波长1对应的端口1与ONT1连接，即存在绑定关系。
进一步地，MAC单元控制波长可调激光器520发送波长λ2的探测光信号，继续确定波长λ2对应的端口2所连接的光终端。
示例二：
分光器的支路上部署的光滤波器均为透射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有透射第一波长的光信号的功能，反射其它波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有反射第一波长的光信号的功能。分光器与第一光终端的连接支路内的光滤波器对于第一波长的探测光信号会执行透射操作，从而将第一波长的探测光信号透射出去。其它的光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的探测光信号发生反射。从而在其它光终端对应的时隙上接收到的光信号中检测到的探测光信号的功率均增强或者均减弱，而第一光终端的时隙上接收到的光信号未检测到的探测光信号的反射光信号，即功率也未发生增强或者减弱。从而第一光终端的时隙上接收到的光信号中检测到的探测光信号的功率相比其它光终端的时隙上接收到的光信号中检测到的探测光信号的功率存在波动。
具体的，其它光终端的上行光信号对所述探测光信号在相对应的连接支路的增益组件上产生交叉增益调制效应或者交叉衰减调制效应，以及针对在所述分光器与所述第一光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路的增益组件上也会产生交叉增益调制效应或者交叉衰减调制效应，从而在其它光终端对应的时隙上接收到的光信号中检测到的探测光信号的功率均增强或者均减弱。
而探测光信号在经过第一光终端所连接的分光器的连接支路的光滤波器时，探测光信号被透射出去，即不会产生探测光信号的反射的光信号，从而第一光终端的上行光信号也不会对反射的光信号的交叉增益调制效应或者交叉衰减调制效应。即第一光终端的时隙上接收到的光信号未检测到的探测光信号的反射光信号，即第一光终端的时隙上的反射光信号的功率未发生增强或者减弱。进一步，可以确定在第一光终端的时隙内接收到的上行光信号中检测到的探测光信号的功率相比在其它的时隙内接收到的上行光信号中检测到的探测光信号的功率发生波动，比如增大或者减少。
作为一种举例，参见图7B所示，光接入网中包括64个ONT，分别为ONT1-ONT64。ONT1-ONT64分别连接不同的分光器的端口。图7B中，以MAC单元510部署于OLT中为 例。OLT还有其它组件，比如光模块等，在图7B中未示出。在分光器连接ONT的每个支路上均部署于有光滤波器。分光器连接ONT的每个支路上还部署增益组件。增益组件指使得两个光信号产生交叉增益调制效应或者交叉衰减调制效应的组件。示例性地，增益组件可以是半导体光放大器，也可以是掺杂的光纤。不同的光滤波器均为透射型滤波器，用于透射不同波长的光信号。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器520调整到波长λ1，连续发射波长λ1的探测光信号。该探测光信号的功率为POAI。该波长λ1的探测光信号分别广播到分光器的各个支路上。该波长λ1的探测光信号在经过端口1的支路的光滤波器时，透射出去。波长λ1的探测光信号在经过端口2-端口64的支路的光滤波器时，反射回来。
MAC单元510中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，波长λ1的探测光信号经过该ONT1对应的分光器的支路的光滤波器时，被透射出去。而轮到其它的ONT2-ONT64发送上行光信号时，在经过增益组件时，ONT2-ONT64的上行光信号对波长λ1的探测光信号和探测光信号的反射光信号均产生交叉增益调制效应或者交叉衰减调制效应，从而在ONT2-ONT64分别对应的时隙上检测到的光信号中探测光信号的功率均增强或者减弱。也就是在ONT2-ONT64分别对应的时隙上检测到的光信号中探测光信号的功率均近似相同。而由于波长λ1的探测光信号经过该ONT1对应的分光器的支路的光滤波器时，被透射出去了，在ONT1对应的时隙上检测到的光信号中探测光信号的功率未被增强或者减弱。光电探测器530在时隙1探测到的探测光信号功率相比其它时隙探测到的探测光信号的功率会发送波动(增大或者减小)。例如参见图7B所示。图7B中虚线表示探测光信号的信号流向。光电探测器530可以检测到功率发生波动的时间窗口。进一步地，MAC单元510根据波长可调激光器的波长λ1、功率发生波动的时间窗口以及各个ONT发送上行光信号的时隙来确定波长1对应的端口1与ONT1连接，即存在绑定关系。
进一步地，MAC单元控制波长可调激光器520发送波长λ2的探测光信号，继续确定波长λ2对应的端口2所连接的光终端。
以下对第二种可能的实现方式进行描述。参见图8所示，为第二种可能的实现方式的光接入网络拓扑的确定方法流程示意图。以光接入网中包括N个光终端为例。N个光终端与光接入网中的多个分光器包括的N个端口一一对应光学连接。N为正整数。一些场景中，光接入网中的ODN采用一级分光器，则该一级分光器包括至少N个端口，N个光终端与至少N个端口中的N个端口一一对应光学连接。另一些场景中，光接入网络中的ODN采用多级分光器，比如两级、三级等等。ODN中的多个末级分光器至少包括N个端口。比如，末级分光器为3个，则3个末级分光器的总端口数量大于或者等于N，N个光终端与3个末级分光器的N个端口一一对应光学连接。
图8提供的光接入网络拓扑的确定方法具体包括以下步骤：
801，连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号。
所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长。 这里的分光器可以是指末级分光器，也可以是上一级分光器，还可以第一级分光器，本申请对此不作具体限定。以两级分光器为例，第一波长可以对应于第一级分光器的端口1或者对应于第二级分光器的端口1。
每个光终端对应的时隙，可以采用DBA方式为每个光终端分配上行发光时隙，也可以采用静态带宽分配方式为每个光终端分配上行发光时隙(简称时隙)。
802，测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率。
一些实施例中，泵浦光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有反射第一波长的探测光信号的功能，光滤波器将该波长的泵浦光信号反射回来。同级的其它分光器的支路上部署的光滤波器针对该第一波长的探测光信号均透射出去。
另一些实施例中，泵浦光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有透射第一波长的泵浦光信号的功能，光滤波器将该波长的探测光信号透射出去。同级的其它分光器的支路上部署的光滤波器针对该第一波长的泵浦光信号均反射回来。
803，根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端。
其中，一个光终端的上行基线接收功率为所述泵浦光信号未进入所述分光器与所述一个光终端之间的连接支路情况下所述一个光终端的上行光信号的接收功率；一个光终端的接收功率与所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
以第一端口所连接的光终端为第一光终端为例。第一光终端对应的时隙为第一时隙。在根据多个光终端中每个光终端的接收功率与每个光终端的上行基线接收功率的变化情况确定第一波长对应的第一端口所连接的光终端的情况下，可以通过如下方式实现：
在第一时隙内接收到的上行光信号的功率与第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差小于设定阈值时，确定第一时隙对应的第一光终端与第一波长对应的第一端口光学连接；或者，
在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差小于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差均大于或者等于设定阈值时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
比如64个ONT，测量每个时隙上接收到的上行光信号的接收功率。然后测量每个时隙对应测量的接收功率与该时隙对应的上行基线接收功率的差。例如，上行基线接收功率通过Prx表示。测量的接收功率通过表示。则获取每个时隙对应的接收功率差。时隙i对应的接收功率差通过表示。满足如下公式(1)或者公式(2)。

其中，表示在时隙i接收到对应的光终端的上行光信号的接收功率。表示时隙i对 应的光终端的上行基线接收功率。
一些实施例中，分光器的支路产生的交叉调制效应为交叉增益调制效应时，采用上述公式(1)，分光器的支路产生的交叉调制效应为交叉衰减调制效应时，采用上述公式(2)。
一些实施例中，在确定分光器的第一端口所连接的光终端后，继续确定其它端口所连接的光终端。比如继续发送第二波长的泵浦光信号，第二波长对应分光器的第二端口，通过图8对应的实施例提供的方式，已确定第二端口所连接的光终端，依次类推，直到确定所有端口所连接的光终端。
一些实施例中，在连续发送第一波长的泵浦光信号之前，控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号，并测量所述多个光终端的上行光信号的接收功率以得到所述多个光终端中每个光终端的上行基线接收功率。每个光终端的上行基线接收功率的标定可以采用多次测量结果的平均值。应理解的是，在测量上行基线接收功率时，泵浦光信号不会进入到ODN，以免干扰上行基线接收功率的标定。比如，以64个ONT为例，一个触发(Trigger)周期为5us，每个ONT的上行基线接收功率可以采用10次测量结果的平均值。则需要的总时长为64×5×10＝3.2ms。
一些场景中，光终端上的激光器为非制冷激光器，非制冷激光器的发射功率易受温度变化的影响。为了避免温度因素的影响，可以缩短标定上行基线接收功率与触发确定分光器端口所连接的光终端之间的时间间隔。作为一种举例，如果波长可调激光器的波长调整时间为5s，上行基线接收功率的标定时长为3.2ms，则在进行上行基线接收功率标定和记录前，提前控制波长可调激光器单独启动波长调整，并确保在上行基线接收功率标定过程中，泵浦光信号不进入光纤，以免干扰基线接收功率的标定。
图8提供的光接入网络拓扑的确定方法可以由光接入网络拓扑的确定装置来实现。该装置可以部署于光头端，比如部署于OLT中。参见图9所示，该装置包括媒体接入控制(media access control，MAC)单元910、波长可调激光器(tunable laser，TL)920和功率测量器930。
MAC单元910可以采用FPGA，可以采用ASIC)，还可以采用SoC)，还可以采用CPU，还可以采用NP，还可以采用DSP，还可以采用MCU，还可以采用PLD或其他集成芯片。波长可调激光器920可以发射多种波长的泵浦光信号。在识别目标ONT(ODN连接的任一ONT)连接的分支支路(支路的端口)时，OLT可以在控制波长可调激光器920可以发出多种波长的泵浦光信号，多种波长的泵浦光信号为每个分支支路上设置的光滤波器所反射的泵浦光信号的波长。
功率测量器可以是光模块930，还可以是接收信号强度指示器(Received Signal Strength Indicator，RSSI)。后续以光模块930为例，图9中以光模块930为例。一些实施例中，MAC单元910、TL920和光模块930均可以集成在一个芯片中，也可以通过不同的芯片来实现。
以确定第一波长对应的分光器的支路的端口所连接的光终端为例。
MAC单元910控制多个光终端分别在每个光终端对应的时隙上发送上行光信号。波长可调激光器920向分光器连续发送第一波长的泵浦光信号。光模块930，用于测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率。
所述MAC单元910，根据所述多个光终端中每个光终端的接收功率相比所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端。
如下以增益组件与光滤波器的部署位置关系为图3A所示的位置为例。
示例三：
分光器的支路上部署的光滤波器均为反射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有反射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有透射第一波长的光信号的功能。
参见图10A所示，分光器与第一光终端的连接支路内的光滤波器对于第一波长的泵浦光信号会执行反射操作，从而将第一波长的泵浦光信号反射回去，从而第一波长的泵浦光信号和经过光滤波器反射泵浦光信号产生的光信号在增益组件内均对第一光终端的上行光信号产生交叉调制效应。由于其它的光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的泵浦光信号不会发生反射，而直接透射出去。从而仅存在第一波长的泵浦光信号对第一光终端的上行光信号产生交叉调制效应，不存在反射光信号对上行光信号产生交叉调制效应。从而在其它光终端对应的时隙上接收到的上行光信号由于泵浦光信号而引发上行光信号的功率变化幅度很小。第一波长的泵浦光信号和经过光滤波器反射泵浦光信号产生的光信号在增益组件内均对第一光终端的上行光信号产生交叉调制效应，引起第一光终端的上行光信号的接收功率的变化幅度较大。
基于此，仅第一光终端的上行光信号的接收功率相比基线接收功率变化幅度较大，即确定第一时隙检测到的上行光信号的接收功率相比第一时隙对应的光终端的基线接收功率变化幅度较大，从而确定第一时隙对应的第一光终端与第一波长对应的分光器的支路端存在绑定关系。
作为一种举例，参见图10B所示，结合图9对本申请实施例提供的光接入网拓扑的确定方法进行说明。以光接入网中包括64个ONT，分别为ONT1-ONT64为例。ONT1-ONT64分别连接不同的分光器的端口。在分光器连接ONT的每个支路上均部署于有光滤波器。分光器连接ONT的每个支路上还部署增益组件。增益组件指使得两个光信号产生交叉增益调制效应或者交叉衰减调制效应的组件。示例性地，增益组件可以是半导体光放大器，也可以是掺杂的光纤。不同的光滤波器用于反射不同波长或者波长组合的光信号。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器920调整到波长λ1，连续发射波长λ1的泵浦光信号。该波长λ1的泵浦光信号分别广播到分光器的各个支路上。该波长λ1的泵浦光信号在经过端口1的支路的光滤波器时，反射回来。波长λ1的泵浦光信号在经过端口2-端口64的支路的光滤波器时，直接透射出去。
MAC单元910中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，在经过增益组件时，波长λ1的泵浦光信号的反射光信号对ONT1的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。光模块930分别测量时隙1-时隙64分别接收的上行光信号的接收功率。MAC单元910比较在每个时隙测量的上行光信号的接收功率与该时隙对应的光终端的上行基线接收功率之间的接收功率差值。MAC单元910根据每个时隙的接收功率差值与设定阈值的比较结果。MAC单元910确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值大于或 者等于设定阈值。进一步地，MAC单元910根据波长可调激光器的波长λ1、接收功率差值对应的光终端确定波长1对应的端口1与ONT1连接，即存在绑定关系。
进一步地，MAC单元910控制波长可调激光器920发送波长λ2的泵浦光信号，继续确定波长λ2对应的端口2所连接的光终端。以此类推。
示例四：
分光器的支路上部署的光滤波器均为透射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有透射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有反射第一波长的光信号的功能。
参见图10C所示，分光器与第一光终端的连接支路内的光滤波器对于第一波长的泵浦光信号会执行透射操作，从而将第一波长的泵浦光信号透射出去，从而仅第一波长的泵浦光信号在增益组件内对第一光终端的上行光信号产生交叉调制效应，不存在反射光信号对上行光信号产生交叉调制效应。从而在第一光终端对应的时隙上接收到的上行光信号由于泵浦光信号而引发上行光信号的功率变化幅度较小。由于其它的光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的泵浦光信号会发生反射。从而第一波长的泵浦光信号和泵浦光信号的反射光信号对其它光终端的上行光信号产生交叉调制效应。从而在其它光终端对应的时隙上接收到的上行光信号由于泵浦光信号和反射光信号而引发上行光信号的功率变化幅度较大。
基于此，仅第一光终端的上行光信号的接收功率相比基线接收功率变化幅度较小，即确定第一时隙检测到的上行光信号的接收功率相比第一时隙对应的光终端的基线接收功率变化幅度较小，其它时隙检测到的上行光信号的接收功率相比其它时隙对应的光终端的基线接收功率变化幅度较大，从而确定第一时隙对应的第一光终端与第一波长对应的分光器的支路端存在绑定关系。
作为一种举例，参见图10D所示，结合图9对本申请实施例提供的光接入网拓扑的确定方法进行说明。以光接入网中包括64个ONT，分别为ONT1-ONT64为例。ONT1-ONT64分别连接不同的分光器的端口。在分光器连接ONT的每个支路上均部署于有光滤波器，且均为透射型滤波器。分光器连接ONT的每个支路上还部署增益组件。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器920调整到波长λ1，连续发射波长λ1的泵浦光信号。该波长λ1的泵浦光信号分别广播到分光器的各个支路上。该波长λ1的泵浦光信号在经过端口1的支路的光滤波器时，透射出去。波长λ1的泵浦光信号在经过端口2-端口64的支路的光滤波器时，反射回来。
MAC单元910中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，仅波长λ1的泵浦光信号经过增益组件时，波长λ1的泵浦光信号对ONT1的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT1的上行光信号的功率相比ONT1的基线接收功率变化幅度较小。当轮到端口2-端口64连接的ONT2-ONT64中任一ONT发送上行光信号时，波长λ1的泵浦光信号和泵浦光信号 的反射光信号均会在增益组件与ONT2-ONT64中任一ONT的上行光信号相遇时，波长λ1的泵浦光信号对ONT2-ONT64中任一ONT的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT2-ONT64中任一ONT的上行光信号的接收功率相比该任一ONT的基线接收功率变化幅度较大。
光模块930分别测量时隙1-时隙64分别接收的上行光信号的接收功率。MAC单元910比较在每个时隙测量的上行光信号的接收功率与该时隙对应的光终端的上行基线接收功率之间的接收功率差值。MAC单元910根据每个时隙的接收功率差值与设定阈值的比较结果。
MAC单元910确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值小于设定阈值，MAC单元910确定时隙2-时隙64接收的上行光信号的接收功率与分别对应的时隙对应的光终端的上行基线接收功率的差值大于或者等于设定阈值。进一步地，MAC单元910根据波长可调激光器的波长λ1、接收功率差值对应的光终端确定波长1对应的端口1与ONT1连接，即存在绑定关系。
如下以增益组件与光滤波器的部署位置关系为图3B所示的位置为例。
示例五：
分光器的支路上部署的光滤波器均为反射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有反射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有透射第一波长的光信号的功能。
参见图10E所示，分光器与第一光终端的连接支路内的光滤波器对于第一波长的泵浦光信号会执行反射操作，从而将第一波长的泵浦光信号反射回去，从而第一波长的泵浦光信号不会到达增益组件，也就不会在增益组件内对第一光终端的上行光信号产生交叉调制效应。其它的光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的泵浦光信号不会发生反射，而直接透射出去而经过增益组件。从而第一波长的泵浦光信号对其它光终端的上行光信号在增益组件内产生交叉调制效应。在其它光终端对应的时隙上接收到的上行光信号由于泵浦光信号而引发上行光信号的功率变化。第一波长的泵浦光信号在增益组件内不会对第一光终端的上行光信号产生交叉调制效应，从而第一光终端的上行光信号的接收功率不会发生变化。
基于此，仅第一光终端的上行光信号的接收功率相比基线接收功率未发生变化，而其它光终端的上行光信号的接收功率相比基线接收功率均发生了变化，即确定第一时隙检测到的上行光信号的接收功率相比第一时隙对应的光终端的基线接收功率未变化，以确定第一时隙对应的第一光终端与第一波长对应的分光器的支路端存在绑定关系。
作为一种举例，参见图10F所示，结合图9提供的确定装置对本申请实施例提供的光接入网拓扑的确定方法进行说明。以光接入网中包括64个ONT，分别为ONT1-ONT64为例。ONT1-ONT64分别连接不同的分光器的端口。在分光器连接ONT的每个支路上均部署于有光滤波器，且均为反射型滤波器。分光器连接ONT的每个支路上还部署增益组件。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器920调整到波长λ1，连续发射波长λ1的泵浦光信号。该波长λ1的泵浦光信号分别广播到分光器的各个支路上。该波长λ1的泵浦光信号在经过端口1的支路的 光滤波器时，反射回去，不会到达端口1的增益组件。波长λ1的泵浦光信号在经过端口2-端口64的支路的光滤波器时，透射出去，会达到端口2-端口64的支路的增益组件。
MAC单元910中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，波长λ1的泵浦光信号不会经过增益组件时，即不会对ONT1的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT1的上行光信号的功率相比ONT1的基线接收功率未发生变化。当轮到端口2-端口64连接的ONT2-ONT64中任一ONT发送上行光信号时，波长λ1的泵浦光信号经过光滤波器后，会在增益组件内与ONT2-ONT64中任一ONT的上行光信号相遇，波长λ1的泵浦光信号对ONT2-ONT64中任一ONT的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT2-ONT64中任一ONT的上行光信号的接收功率相比该任一ONT的基线接收功率发生变化。
光模块930分别测量时隙1-时隙64分别接收的上行光信号的接收功率。MAC单元910比较在每个时隙测量的上行光信号的接收功率与该时隙对应的光终端的上行基线接收功率之间的接收功率差值。MAC单元910根据每个时隙的接收功率差值与设定阈值的比较结果。
MAC单元910确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值小于设定阈值(近似为0)，MAC单元910确定时隙2-时隙64接收的上行光信号的接收功率与分别对应的时隙对应的光终端的上行基线接收功率的差值大于或者等于设定阈值。进一步地，MAC单元910根据波长可调激光器的波长λ1、接收功率差值小于设定阈值的光终端确定波长1对应的端口1与ONT1连接，即存在绑定关系。
示例六：
分光器的支路上部署的光滤波器均为反射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有反射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有透射第一波长的光信号的功能。
参见图10G所示，分光器与其它光终端的连接支路内的光滤波器对于第一波长的泵浦光信号会执行反射操作，从而将第一波长的泵浦光信号反射回去，从而第一波长的泵浦光信号不会到达增益组件，也就不会在增益组件内对其它光终端的上行光信号产生交叉调制效应。第一波长的泵浦光信号在增益组件内不会对其它光终端的上行光信号产生交叉调制效应，从而其它光终端的上行光信号的接收功率不会发生变化。第一光终端所连接的分光器的端口对应的支路上光滤波器针对第一波长的泵浦光信号不会发生反射，而直接透射出去而经过增益组件。从而第一波长的泵浦光信号对第一光终端的上行光信号在增益组件内产生交叉调制效应。在第一光终端对应的第一时隙上接收到的上行光信号由于泵浦光信号而引发上行光信号的功率变化。
基于此，仅第一光终端的上行光信号的接收功率相比基线接收功率发生了变化，而其它光终端的上行光信号的接收功率相比基线接收功率均未发生变化，即确定第一时隙检测到的上行光信号的接收功率相比第一时隙对应的光终端的基线接收功率发生变化，以确定第一时隙对应的第一光终端与第一波长对应的分光器的支路端存在绑定关系。
作为一种举例，参见图10H所示，结合图9提供的确定装置对本申请实施例提供的光接 入网拓扑的确定方法进行说明。以光接入网中包括64个ONT，分别为ONT1-ONT64为例。ONT1-ONT64分别连接不同的分光器的端口。在分光器连接ONT的每个支路上均部署于有光滤波器，且均为透射型滤波器。分光器连接ONT的每个支路上还部署增益组件。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器920调整到波长λ1，连续发射波长λ1的泵浦光信号。该波长λ1的泵浦光信号分别广播到分光器的各个支路上。该波长λ1的泵浦光信号在经过端口1的支路的光滤波器时，透射出去，会到达端口1的增益组件。波长λ1的泵浦光信号在经过端口2-端口64的支路的光滤波器时，反射回去，不会达到端口2-端口64的支路的增益组件。
MAC单元910中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，波长λ1的泵浦光信号会经过增益组件时，即会对ONT1的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT1的上行光信号的功率相比ONT1的基线接收功率发生变化。当轮到端口2-端口64连接的ONT2-ONT64中任一ONT发送上行光信号时，波长λ1的泵浦光信号经过光滤波器被反射回去未到达增益组件，从而不会在增益组件内与ONT2-ONT64中任一ONT的上行光信号相遇，波长λ1的泵浦光信号也就不会对ONT2-ONT64中任一ONT的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT2-ONT64中任一ONT的上行光信号的接收功率不会发生变化。
光模块930分别测量时隙1-时隙64分别接收的上行光信号的接收功率。MAC单元910比较在每个时隙测量的上行光信号的接收功率与该时隙对应的光终端的上行基线接收功率之间的接收功率差值。MAC单元910根据每个时隙的接收功率差值与设定阈值的比较结果。
MAC单元910确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值大于或者等于给设定阈值，MAC单元910确定时隙2-时隙64接收的上行光信号的接收功率与分别对应的时隙对应的光终端的上行基线接收功率的差值小于设定阈值((近似为0))。进一步地，MAC单元910根据波长可调激光器的波长λ1、接收功率差值大于或者等于设定阈值的光终端确定波长1对应的端口1与ONT1连接，即存在绑定关系。
以下对第三种可能的实现方式进行描述。参见图11所示，为第三种可能的实现方式的光接入网络拓扑的确定方法流程示意图。以光接入网中包括N个光终端为例。N个光终端与光接入网中的多个分光器包括的N个端口一一对应光学连接。N为正整数。一些场景中，光接入网中的ODN采用一级分光器，则该一级分光器包括至少N个端口，N个光终端与至少N个端口中的N个端口一一对应光学连接。另一些场景中，光接入网络中的ODN采用多级分光器，比如两级、三级等等。ODN中的多个末级分光器至少包括N个端口。比如，末级分光器为3个，则3个末级分光器的总端口数量大于或者等于N，N个光终端与3个末级分光器的N个端口一一对应光学连接。
图11提供的光接入网络拓扑的确定方法具体包括以下步骤：
1101，连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号。
所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长。这里的分光器可以是指末级分光器，也可以是上一级分光器，还可以第一级分光器，本申请 对此不作具体限定。以两级分光器为例，第一波长可以对应于第一级分光器的端口1或者对应于第二级分光器的端口1。
每个光终端对应的时隙，可以采用DBA方式为每个光终端分配上行发光时隙，也可以采用静态带宽分配方式为每个光终端分配上行发光时隙(简称时隙)。
泵浦光信号调制有设定信息。设定信息可以是设定频率信息，或者设定码型。
1102，测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率，和/或，从在所述多个光终端分别对应的时隙上接收到的上行光信号检测所述设定信息得到每个时隙的检测结果。
一些实施例中，泵浦光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有反射第一波长的探测光信号的功能，光滤波器将该波长的泵浦光信号反射回来。同级的其它分光器的支路上部署的光滤波器针对该第一波长的探测光信号均透射出去。
另一些实施例中，泵浦光信号到达ODN后，经过某个分光器的支路上部署的光滤波器后，比如，该分支器的支路上的光滤波器具有透射第一波长的泵浦光信号的功能，光滤波器将该波长的探测光信号透射出去。同级的其它分光器的支路上部署的光滤波器针对该第一波长的泵浦光信号均反射回来。
1103，根据检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
测量得到的一个光终端的接收功率相比所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
接收到的一个光终端的上行光信号的设定信息是：泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应，使得泵浦光信号携带的设定信息调制到该光终端的上行光信号而产生的。
根据检测结果确定所述第一波长对应的所述第一端口所连接的光终端，可以通过如下任一方式实现：
方式1：在第一时隙内接收到的上行光信号的功率与第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值且在其它时隙内接收到的上行光信号的功率与其它时隙对应的光终端的上行基线接收功率的差小于设定阈值时，确定第一时隙对应的第一光终端与第一波长对应的第一端口光学连接。
方式2：在第一时隙内接收到的上行光信号检测到设定信息时，确定第一时隙对应的第一光终端与第一波长对应的第一端口光学连接。
方式3：在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均小于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
方式4：在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差大于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差满足上述公式(1)和公式(2)的条件。
第三种可能的方式与第二种可能的方式中的光路传输原理类似，此处不再赘述。可以理解在泵浦光信号到达增益组件对某一光终端的上行光信号产生交叉调制效应的情况下，泵浦光信号中的设定信息被调制到该光终端的上行光信号中。而未产生交叉调制效应的情况下，不会被调制到该光终端的上行光信号中。从而可以根据设定信息的检测情况来确定光终端与分光器的支路端口的绑定关系。
一些实施例中，在连续发送第一波长的泵浦光信号之前，执行每个光终端的上行基线接收功率的标定，具体参见第二种可能的实现方式中的相关描述，此处不再赘述。
图11提供的光接入网络拓扑的确定方法可以由光接入网络拓扑的确定装置来实现。该装置可以部署于光头端，比如部署于OLT中。参见图12所示，该装置包括MAC单元1210和TL 1220和信号检测器1230。
MAC单元1210可以采用FPGA，可以采用ASIC，还可以采用SoC，还可以采用CPU，还可以采用NP，还可以采用DSP，还可以采用MCU，还可以采用PLD或其他集成芯片。波长可调激光器1220可以发射多种波长的泵浦光信号。在识别目标ONT(ODN连接的任一ONT)连接的分支支路(支路的端口)时，OLT可以在控制波长可调激光器1220可以发出多种波长的泵浦光信号，多种波长的泵浦光信号为每个分支支路上设置的光滤波器所反射的泵浦光信号的波长。
信号检测器可以是光模块1230，还可以是接收机。信号检测器具有接收信号强度指示(Received Signal Strength Indicator，RSSI)检测功能以及设定频率或者设定码型的相关检测功能。后续以信号检测器为光模块1230为例。一些实施例中，MAC单元1210、TL1220和光模块1230均可以集成在一个芯片中，也可以通过不同的芯片来实现。
以确定第一波长对应的分光器的支路的端口所连接的光终端为例。
MAC单元1210控制多个光终端分别在每个光终端对应的时隙上发送上行光信号。波长可调激光器1220向分光器连续发送第一波长的泵浦光信号，该第一波长的泵浦光信号调制有设定信息。光模块1230，用于测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率，以及从所述多个光终端分别对应的时隙上接收到的上行光信号检测特定信息得到检测结果。
所述MAC单元1210，根据检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
如下以增益组件与光滤波器的部署位置关系为图3B所示的位置为例。
示例七：
分光器的支路上部署的光滤波器均为反射型滤波器。第一端口所连接的光终端为第一光终端。第一光终端对应的时隙为第一时隙。第一光终端所连接的分光器的支路部署的光滤波器具有反射第一波长的光信号的功能。其它光终端所连接的分光器的支路部署的光滤波器均具有透射第一波长的光信号的功能。
参见图13所示，以光接入网中包括64个ONT，分别为ONT1-ONT64为例。ONT1-ONT64分别连接不同的分光器的端口。图13中，以信号检测器1230是光模块1230为例。在分光器连接ONT的每个支路上均部署于有光滤波器，且均为反射型滤波器。分光器连接ONT的每 个支路上还部署增益组件。增益组件指使得两个光信号产生交叉增益调制效应或者交叉衰减调制效应的组件。示例性地，增益组件可以是半导体光放大器，也可以是掺杂的光纤。不同的光滤波器用于反射不同波长或者波长组合的光信号。ONT1-ONT64分别连接的分光器的端口为端口1-端口64。端口1-端口64的支路的光滤波器对应的波长分别为λ1-λ64。
波长可调激光器1220调整到波长λ1，连续发射波长λ1的泵浦光信号。该波长λ1的泵浦光信号分别广播到分光器的各个支路上。该波长λ1的泵浦光信号在经过端口1的支路的光滤波器时，反射回去，不会到达端口1的增益组件。波长λ1的泵浦光信号在经过端口2-端口64的支路的光滤波器时，透射出去，会达到端口2-端口64的支路的增益组件。
MAC单元1210中轮流控制所有在线ONT在特定时隙内发送上行光信号。不同的ONT对应不同的时隙，ONT1-ONT64对应的时隙分别为时隙1-时隙64。当轮到与波长λ1相对应端口1连接的ONT1发送上行光信号时，波长λ1的泵浦光信号不会经过增益组件时，即不会对ONT1的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT1的上行光信号的功率相比ONT1的基线接收功率未发生变化，并且上行光信号中也不会调制有设定信息。当轮到端口2-端口64连接的ONT2-ONT64中任一ONT发送上行光信号时，波长λ1的泵浦光信号经过光滤波器后，会在增益组件内与ONT2-ONT64中任一ONT的上行光信号相遇，波长λ1的泵浦光信号对ONT2-ONT64中任一ONT的上行光信号产生交叉增益调制效应或者交叉衰减调制效应。使得ONT2-ONT64中任一ONT的上行光信号的接收功率相比该任一ONT的基线接收功率发生变化，并且使得ONT2-ONT64中任一ONT的上行光信号被调制有设定信息。
光模块1230分别测量时隙1-时隙64分别接收的上行光信号的接收功率以及分别从时隙1-时隙64分别接收的上行光信号检测设定信息。MAC单元1210比较在每个时隙测量的上行光信号的接收功率与该时隙对应的光终端的上行基线接收功率之间的接收功率差值。MAC单元1210获得每个时隙的接收功率差值与设定阈值的比较结果和/或包括设定信息的上行光信号所在的时隙。比如，MAC单元1210确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值小于设定阈值(近似为0)，MAC单元1210确定时隙2-时隙64接收的上行光信号的接收功率与分别对应的时隙对应的光终端的上行基线接收功率的差值大于或者等于设定阈值。进一步地，MAC单元1210根据波长可调激光器的波长λ1、接收功率差值对应的光终端确定波长1对应的端口1与ONT1连接，即存在绑定关系。再比如，MAC单元1210确定从时隙1接收的上行光信号未检测到设定信息，而从其它时隙接收的上行光信号中均检测到设定信息。进一步地，MAC单元1210根据波长可调激光器的波长λ1、时隙1对应的光终端确定波长1对应的端口1与ONT1连接。再比如，MAC单元1210确定时隙1接收的上行光信号的接收功率与时隙1对应的光终端的上行基线接收功率的差值小于设定阈值(近似为0)，MAC单元1210确定时隙2-时隙64接收的上行光信号的接收功率与分别对应的时隙对应的光终端的上行基线接收功率的差值大于或者等于设定阈值，且从时隙1接收的上行光信号未检测到设定信息，而从其它时隙接收的上行光信号中均检测到设定信息，根据波长可调激光器的波长λ1、时隙1对应的光终端确定波长1对应的端口1与ONT1连接。
进一步地，MAC单元1210控制波长可调激光器1220发送波长λ2的泵浦光信号，继续确定波长λ2对应的端口2所连接的光终端。以此类推。
本领域的技术人员可以清楚地了解到，为了描述的方便和简洁，上述描述的通信系统的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
本申请的一个实施例提供了一种计算机可读介质，用于存储计算机程序，该计算机程序包括用于执行图4对应的方法实施例中的方法步骤的指令。
本领域内的技术人员应明白，本申请的实施例可提供为方法、系统、或计算机程序产品。因此，本申请可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本申请可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、光学存储器等)上实施的计算机程序产品的形式。
本申请是参照根据本申请实施例的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (23)

  1. 一种光接入网拓扑的确定方法，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的不同端口一一对应光学连接，所述方法包括：
    连续发送第一波长的探测光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；
    在所述多个光终端分别对应的时隙上接收的光信号中检测所述探测光信号的反射光信号的功率；
    根据在接收的光信号中检测到所述反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端；
    其中，在接收的光信号中检测到的所述反射光信号的功率变化是：一个光终端的上行光信号对所述探测光信号以及在所述分光器与所述一个光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
  2. 如权利要求1所述的方法，其特征在于，根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端，包括：
    确定在接收的光信号中检测到的反射光信号的功率发生变化的时间窗口位于第一时隙时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  3. 一种光接入网拓扑的确定装置，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、波长可调激光器、光电探测器以及环形器，所述环形器的第一端口与所述波长可调激光器光学连接，所述环形器的第二端口与所述分光器光学连接，所述环形器的第三端口与所述光电探测器光学连接；
    所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
    所述波长可调激光器，用于通过环形器向所述分光器连续发送第一波长的探测光信号；
    所述光电探测器，用于在所述多个光终端分别对应的时隙上通过所述环形器接收的光信号中检测所述探测光信号的反射光信号的功率；
    所述MAC单元，还用于根据在接收的光信号中检测到探测光信号的反射光信号的功率发生变化的时间窗口与所述多个光终端分别对应的时隙的关系确定所述第一波长对应的所述第一端口所连接的光终端；
    其中，在接收的光信号中检测到探测光信号的反射光信号的功率发生变化是：一个光终端的上行光信号对所述探测光信号以及在所述分光器与所述一个光终端的连接支路内的光滤波器反射所述探测光信号得到的光信号，在所述连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
  4. 如权利要求3所述的装置，其特征在于，所述MAC单元，具体用于：
    确定所述反射光信号的功率发生变化的时间窗口位于第一时隙时，确定所述第一时隙对 应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  5. 一种光接入网拓扑的确定方法，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述方法包括：
    连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；
    测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率；
    根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端；
    其中，一个光终端的上行基线接收功率为所述泵浦光信号未进入所述分光器与所述一个光终端之间的光纤情况下所述一个光终端的上行光信号的接收功率；一个光终端的接收功率与所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
  6. 如权利要求5所述的方法，其特征在于，所述根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端，包括：
    在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差小于设定阈值，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差小于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差均大于或者等于设定阈值，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  7. 如权利要求5所述的方法，其特征在于，所述泵浦光信号是经过设定信息的调制得到的，所述根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端，包括：
    在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均小于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均大于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  8. 如权利要求7所述的方法，其特征在于，所述设定信息包括设定频率和/或设定码型。
  9. 如权利要求5-8任一项所述的方法，其特征在于，所述方法还包括：
    在连续发送第一波长的泵浦光信号之前，控制所述多个光终端分别在每个光终端对应的 时隙上发送上行光信号，并测量所述多个光终端的上行光信号的接收功率以得到所述多个光终端中每个光终端的上行基线接收功率。
  10. 一种光接入网拓扑的确定装置，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、光模块以及波长可调激光器；
    所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
    所述波长可调激光器，用于连续发送第一波长的探测光信号；
    所述光模块，用于测量在所述多个光终端分别对应的时隙上接收到的上行光信号的接收功率；
    所述MAC单元，根据所述多个光终端中每个光终端的接收功率与所述每个光终端的上行基线接收功率的变化情况确定所述第一波长对应的所述第一端口所连接的光终端；
    其中，一个光终端的上行基线接收功率为所述泵浦光信号未进入所述分光器与所述一个光终端之间的光纤情况下所述一个光终端的上行光信号的接收功率；一个光终端的接收功率与所述一个光终端的上行基线接收功率的变化是所述泵浦光信号对所述一个光终端的上行光信号在所述分光器与所述第一光终端的连接支路内产生交叉增益调制效应或者交叉衰减调制效应产生的。
  11. 如权利要求10所述的装置，其特征在于，所述MAC单元，具体用于：
    在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差大于或者等于设定阈值，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差小于设定阈值时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在第一时隙内接收到的上行光信号的功率与所述第一时隙对应的第一光终端的上行基线接收功率的差小于设定阈值时，且在除第一时隙以外的其它任一时隙内接收到的上行光信号的功率与所述其它任一时隙对应的光终端的上行基线接收功率的差均大于或者等于设定阈值时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  12. 如权利要求10所述的装置，其特征在于，所述泵浦光信号是经过设定信息的调制得到的，所述光模块，还用于从多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息；
    所述MAC单元，具体用于：
    在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均小于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在多个光终端对应的多个时隙中每个时隙接收到的上行光信号的功率与所述每个时隙对应的光终端的上行基线接收功率的差均大于设定阈值，且在第一时隙内接收到的上行光信号中检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  13. 如权利要求12所述的装置，其特征在于，所述设定信息包括设定频率和/或设定码型。
  14. 如权利要求10-13任一项所述的装置，其特征在于，所述MAC单元，还用于在连续发送第一波长的泵浦光信号之前，控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
    所述光模块，还用于测量所述多个光终端的上行光信号的接收功率以得到所述多个光终端中每个光终端的上行基线接收功率。
  15. 一种光接入网拓扑的确定方法，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述方法包括：
    连续发送第一波长的泵浦光信号，并控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；所述第一波长与所述分光器的第一端口对应，所述分光器的不同端口对应不同的波长；所述泵浦光信号是经过设定信息的调制得到的；
    在所述多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息得到每个时隙的检测结果；
    根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
  16. 如权利要求15所述的方法，其特征在于，根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端，包括：
    在第一时隙内接收到的上行光信号检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号未检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在第一时隙内接收到的上行光信号未检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号检测到设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接。
  17. 如权利要求15或16所述的方法，其特征在于，所述设定信息包括设定频率和/或设定码型。
  18. 一种光接入网拓扑的确定装置，其特征在于，所述光接入网包括多个光终端，所述多个光终端与光接入网中的分光器的多个端口一一对应光学连接，所述装置包括媒体接入控制MAC单元、光模块以及波长可调激光器；
    所述MAC单元，用于控制所述多个光终端分别在每个光终端对应的时隙上发送上行光信号；
    所述波长可调激光器，用于连续发送第一波长且调制有设定信息的探测光信号；
    所述光模块，用于在所述多个光终端分别对应的时隙接收到的上行光信号中检测所述设定信息得到每个时隙的检测结果；
    所述MAC单元，根据每个时隙的检测结果确定所述第一波长对应的所述第一端口所连接的光终端。
  19. 如权利要求18所述的装置，其特征在于，所述MAC单元，具体用于：
    在第一时隙内接收到的上行光信号检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号未检测到所述设定信息时，确定所述第一时隙对应的第一光终端与所述第一波长对应的所述第一端口光学连接；或者，
    在第一时隙内接收到的上行光信号未检测到所述设定信息，且在除第一时隙以外的其它任一时隙内接收到的上行光信号检测到设定信息时，确定所述第一时隙对应的第一光终端与 所述第一波长对应的所述第一端口光学连接。
  20. 如权利要求18或19所述的装置，其特征在于，所述设定信息包括设定频率和/或设定码型。
  21. 一种光接入网拓扑的确定系统，其特征在于，包括如权利要求3-4任一项所述的装置或者如权利要求10-14任一项所述的装置或者如权利要求18-20任一项所述的装置，所述系统还包括光分配网络ODN和多个光终端，所述ODN与多个光终端光学连接，所述ODN中包括一个分光器或者多个分光器；
    所述ODN中分光器与所述多个光终端中每个光终端的连接支路内部署有光滤波器，其中，不同连接支路上光滤波器对应不同的波长，用于对不同波长的光信号进行反射或者透射。
  22. 如权利要求21所述的系统，其特征在于，所述ODN中分光器与多个光终端中每个光终端的连接支路内还部署增益组件，所述增益组件位于所述分光器分支端与所述光滤波器之间，或者所述增益组件位于所述光滤波器与所述光终端之间；
    所述增益组件支持对同时接收到的多个光信号产生交叉增益调制效应或者交叉衰减效应。
  23. 如权利要求21或22所述的系统，其特征在于，所述光滤波器为布拉格光栅FBG。
PCT/CN2023/102644 2022-09-06 2023-06-27 一种光接入网拓扑的确定方法、装置及系统 WO2024051286A1 (zh)

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Publication number Priority date Publication date Assignee Title
WO2021098330A1 (zh) * 2019-11-19 2021-05-27 华为技术有限公司 识别光网络单元连接端口的方法、相关装置及系统
CN114128305A (zh) * 2019-08-26 2022-03-01 华为技术有限公司 确定光网络终端连接的方法、设备及系统
WO2022110900A1 (zh) * 2020-11-27 2022-06-02 华为技术有限公司 光分配网络、光网络系统、分光器及分光器的端口识别方法

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114128305A (zh) * 2019-08-26 2022-03-01 华为技术有限公司 确定光网络终端连接的方法、设备及系统
WO2021098330A1 (zh) * 2019-11-19 2021-05-27 华为技术有限公司 识别光网络单元连接端口的方法、相关装置及系统
WO2022110900A1 (zh) * 2020-11-27 2022-06-02 华为技术有限公司 光分配网络、光网络系统、分光器及分光器的端口识别方法

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