Filtering device applying passive optical network and wavelength conflict terminal detection method

Abstract

The invention discloses a filtering device applying a passive optical network and a wavelength conflict terminal detection method. The filtering device is arranged on an optical path of a passive optical network (PON) and used for directly connecting an optical signal of a first wavelength and cutting off an optical signal of a second wavelength, the first wavelength comprises a wavelength where the first passive optical network and a second passive optical network coexist, and the second wavelength comprises a wavelength where the first passive optical network and the second passive optical network conflict.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of optical access networks, and in particular to a filtering device using a passive optical network and a method for detecting a wavelength conflict terminal. Background Art

[0002] Passive Optical Network (PON) technology is a point-to-multipoint (P2MP) broadband access technology based on passive optical distribution network (ODN). PON adopts P2MP topology. One PON port can connect multiple optical network units (ONU), and the resources of the central office equipment (Optical Line Terminal, OLT, also known as optical line terminal) are greatly reduced. At the same time, the intermediate ODN is passive, easy to build and expand, and has a low overall cost.

[0003] The PON system has gone through three generations of development, including the first generation of Gigabit-Capable Passive Optical Network (GPON) and Ethernet Passive Optical Network (EPON), the second generation of 10G EPON and XG(S)-PON, and the third generation of 50G PON. The coexistence of 50G PON and traditional PON mainly includes the coexistence evolution of EPON and GPON systems. In the GPON system, the wavelength planning of 50G PON supports the coexistence of GPON and XG / XGS-PON wavelength division, and can be evolved and upgraded by means of external combiners or built-in optical modules in combiners. The upstream wavelength of EPON and the asymmetric non-narrowed upstream wavelength of 10G EPON are distributed in the range of 1260-1360nm, which conflicts with the upstream and downstream working wavelengths of 50GPON. The current available solution is to upgrade and replace all existing EPON and asymmetric non-narrowed 10G EPON terminals, and only use 10G EPON and 50G PON systems to coexist, resulting in a waste of a large number of EPON terminal equipment resources that have been laid in the existing network. Summary of the invention

[0004] The embodiments of the present application provide a filtering device using a passive optical network and a detection method for a wavelength conflict terminal, which can solve the problem of resource waste caused by upgrading the passive optical network when there is a wavelength conflict in the passive optical network.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, a filtering device for use in a passive optical network is provided. The filtering device is arranged on an optical path of a passive optical network PON and is used to pass an optical signal of a first wavelength and cut off an optical signal of a second wavelength, wherein the first wavelength includes: a wavelength at which the first passive optical network and the second passive optical network coexist, and the second wavelength includes: a wavelength at which the first passive optical network and the second passive optical network conflict.

[0007] In a second aspect, a method for detecting a wavelength conflict terminal is provided, which is applied to a passive optical network system provided with a filtering device as described in the first aspect, the method comprising: a central office device OLT detects that a first optical network unit connected to its PON port is offline or operatively abnormal, wherein the first optical network unit comprises: an optical network unit of a first-generation passive optical network and / or a second-generation passive optical network; the central office device OLT determines that an operating wavelength of the first optical network unit conflicts with a wavelength of a target passive optical network, wherein the target passive optical network comprises: a third-generation passive optical network.

[0008] The technical solution provided by this application may have the following beneficial effects:

[0009] In an embodiment of the present application, a filtering device for applying a passive optical network is arranged on an optical path of a passive optical network PON, an optical signal of a first wavelength is passed directly, and an optical signal of a second wavelength is cut off, wherein the first wavelength includes a wavelength coexisting with the first passive optical network and the second passive optical network, and the second wavelength includes a wavelength in conflict with the first passive optical network and the second passive optical network, so that when a wavelength in conflict exists between the first generation passive optical network and / or the second generation passive optical network and the third generation passive optical network, the optical signal of the wavelength in conflict exists between the first generation passive optical network and / or the second generation passive optical network and the third generation passive optical network can be cut off, so that the central office equipment OLT can judge whether the working wavelength of the network unit conflicts with the wavelength of the third generation passive optical network according to whether the optical network unit connected to its PON port is offline or working abnormally, and then only the optical network unit in conflict can be replaced, avoiding the problem of resource waste caused by replacing a large number of EPON terminal equipment.

[0010] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0012] Figure 1 A schematic structural diagram of a filtering device using a passive optical network provided by an exemplary embodiment of the present application is shown;

[0013] Figure 2 A schematic structural diagram of another filtering device using a passive optical network provided by an exemplary embodiment of the present application is shown;

[0014] Figure 3 A schematic structural diagram of another filtering device using a passive optical network provided by an exemplary embodiment of the present application is shown;

[0015] Figure 4 A flow chart of a wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown;

[0016] Figure 5 A flow chart showing another wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown;

[0017] Figure 6 A wavelength processing schematic diagram of a filtering device provided by an exemplary embodiment of the present application is shown;

[0018] Figure 7 A flow chart of another wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0020] Figure 1 A schematic diagram of the structure of a filtering device using a passive optical network provided by an exemplary embodiment of the present application is shown. Figure 1 The filtering device 100 is arranged on an optical path 11 of a passive optical network (PON) and is used to pass an optical signal of a first wavelength 12 and cut off an optical signal of a second wavelength 13, wherein the first wavelength includes: a wavelength at which the first passive optical network and the second passive optical network coexist, and the second wavelength includes: a wavelength at which the first passive optical network and the second passive optical network conflict.

[0021] Among them, the first passive optical network may include: a first-generation passive optical network and / or a second-generation passive optical network, and the second passive optical network may include: a third-generation passive optical network; the first-generation passive optical network may include an Ethernet Passive Optical Network (EPON), the second-generation passive optical network may include 10G EPON, and the third-generation passive optical network may include 50G PON.

[0022] In the embodiment of the present application, by means of the filtering device 100 arranged on the optical path 11 of the passive optical network PON, the optical signal of the first wavelength 12 is passed directly, and the optical signal of the second wavelength 13 is cut off, wherein the first wavelength includes the wavelength coexisting with the first passive optical network and the second passive optical network, and the second wavelength includes the wavelength in conflict with the first passive optical network and the second passive optical network, so that when the wavelength in conflict exists between the first generation passive optical network and / or the second generation passive optical network and the third generation passive optical network, the optical signal of the wavelength in conflict exists between the first generation passive optical network and / or the second generation passive optical network and the third generation passive optical network can be cut off, so that the central office equipment (Optical Line Terminal, OLT, also known as optical line terminal) can judge whether the working wavelength of the network unit conflicts with the wavelength of the third generation passive optical network according to whether the optical network unit connected to its PON port is offline or working abnormally, and then only the optical network unit in conflict can be replaced, avoiding the problem of resource waste caused by replacing a large number of EPON terminal equipment.

[0023] In one implementation, the first wavelength is different from the downlink wavelength of the second passive optical network.

[0024] Wherein, if the first wavelength is different from the downstream wavelength of the second passive optical network, there is no conflict between the first wavelength and the downstream wavelength of the second passive optical network, and the above-mentioned filtering device directly passes the optical signal of the first wavelength.

[0025] In an implementation manner, when the first passive optical network and the second passive optical network adopt wavelength division multiplexing, the first wavelength is different from the uplink wavelength of the second passive optical network.

[0026] When the first passive optical network and the second passive optical network adopt wavelength division multiplexing, the first wavelength is different from the upstream wavelength of the second passive optical network, and there is no conflict between the first wavelength and the upstream wavelength of the second passive optical network. The above-mentioned filtering device directly passes the optical signal of the first wavelength.

[0027] In an implementation manner, when the first passive optical network and the second passive optical network adopt time division multiplexing, the first wavelength is the same as the uplink wavelength of the second passive optical network.

[0028] Among them, the first passive optical network and the second passive optical network adopt time division multiplexing. Even if the first passive optical network and the second passive optical network use the same wavelength, they can transmit at different times. Therefore, when the first passive optical network and the second passive optical network adopt time division multiplexing, the first wavelength can be the same wavelength as the uplink wavelength of the second passive optical network.

[0029] In one implementation, the first passive optical network includes: a first generation passive optical network and / or a second generation passive optical network, and the second passive optical network includes: a third generation passive optical network. The first generation passive optical network may include EPON, the second generation passive optical network may include 10G EPON, and the third generation passive optical network may include 50G PON.

[0030] Figure 2 FIG. 1 shows a schematic diagram of a structure of another filtering device using a passive optical network provided by an exemplary embodiment of the present application in an implementation manner, see FIG. Figure 2 The filtering device 200 is arranged between the optical fiber connector 21 of the central office equipment OLT optical module and the receiver 22; the central office equipment OLT optical module is an optical module supporting the first generation passive optical network and / or the second generation passive optical network.

[0031] In an embodiment of the present application, a filtering device 200 is provided between the optical fiber connector 21 and the receiver 22 of the central office device OLT optical module to pass the optical signal of the first wavelength directly and cut off the optical signal of the second wavelength. The first wavelength includes: a wavelength at which the first passive optical network and the second passive optical network coexist. The second wavelength includes: a wavelength at which the first passive optical network and the second passive optical network conflict. The first passive optical network includes: a first-generation passive optical network and / or a second-generation passive optical network. The second passive optical network includes: a third-generation passive optical network. For example, when the first generation passive optical network is EPON, the second generation passive optical network is 10G EPON, and the third generation passive optical network is 50G PON, the 50G PON upstream wavelength uses 1284-1288nm, the downstream wavelength uses 1340-1344nm, and the EPON upstream wavelength is 1260-1360nm. Some terminal wavelengths will conflict with the 50G PON upstream and downstream wavelengths. At this time, the second wavelength includes 1284-1288nm, 1340-1344nm, and the corresponding filter transition band wavelength that needs to be added. The first wavelength is all wavelengths within the upstream wavelength range of EPON and 10G EPON except the second wavelength.

[0032] Figure 3 FIG. 1 shows a schematic diagram of a structure of another filtering device using a passive optical network provided by an exemplary embodiment of the present application in an implementation manner, see FIG. Figure 3 The filtering device 300 is arranged in the uplink receiving optical path of the OLT optical module of the central office device, and is located after the output interface 31 of the OLT optical module of the central office device.

[0033] In one implementation, the filtering device 300 includes one of the following: an optical fiber connector, a box filter, and a wavelength detection line card located in an OLT frame of an office terminal device.

[0034] Optionally, the box filter may be located inside the OLT optical module of the central office device; or may be located in any optical fiber path outside the OLT optical module of the central office device.

[0035] In one implementation, Figure 3 As shown, the above-mentioned filtering device 300 may include: an uplink and downlink optical signal separator 32, a filter 33 and an uplink and downlink optical signal combiner 34; wherein the uplink and downlink optical signal separator and the uplink and downlink optical signal combiner are connected in series between the output interface 31 of the OLT optical module of the central office device and the optical distribution network (Optical Distibution Network, ODN) interface 35 of the OLT of the central office device; the filter 33 is connected to the uplink and downlink optical signal separator 32 at one end and to the uplink and downlink optical signal combiner 34 at the other end, and is used to cut off the optical signal of the second wavelength.

[0036] In the embodiment of the present application, the filtering device 300 is composed of an uplink and downlink optical signal separator 32 and the uplink and downlink optical signal combiner 34 connected in series between the output interface 31 of the central office device OLT optical module and the optical distribution network ODN interface 35 of the central office device OLT, and a filter 33 having one end connected to the uplink and downlink optical signal separator 32 and the other end connected to the uplink and downlink optical signal combiner 34. When there is a conflicting wavelength between the first passive optical network and the second passive optical network, the optical signal of the second wavelength can be cut off, thereby solving the problem of the conflicting wavelength.

[0037] Figure 4 A flowchart of a wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown. The method can be executed by a passive optical network system provided with the above-mentioned filtering device. Figure 4 As shown, the method mainly includes the following steps.

[0038] Step 402, the central office equipment OLT detects that the first optical network unit connected to its PON port is working abnormally, wherein the first optical network unit includes: an optical network unit of a first generation passive optical network and / or a second generation passive optical network;

[0039] The first generation passive optical network may include EPON, and the second generation passive optical network may include 10G EPON. For example, the operation abnormality of the first optical network unit connected to the PON port of the central office device OLT may include at least one of the following: the PON port of the central office device OLT is disconnected from the first optical network unit; the first optical network unit is offline; the throughput of the first optical network unit decreases; and the first optical network unit has packet loss.

[0040] Step 404: the central office equipment OLT determines that the working wavelength of the first optical network unit conflicts with the wavelength of the target passive optical network, wherein the target passive optical network includes: a third generation passive optical network.

[0041] In an embodiment of the present application, when the central office device OLT detects that the first optical network unit connected to its PON port is offline or malfunctioning, it determines that the operating wavelength of the first optical network unit conflicts with the wavelength of the target passive optical network, thereby identifying that the first optical network unit needs to be replaced, rather than replacing all ONUs of the first-generation passive optical network and the second-generation passive optical network, thereby avoiding waste of resources and saving costs.

[0042] In one implementation, after the above-mentioned step 404, the above-mentioned method also includes: replacing the first optical network unit with a second optical network unit whose working wavelength does not conflict with the wavelength of the target passive optical network, wherein the second optical network unit includes one of the following: an optical network unit of a first-generation passive optical network, an optical network unit of a second-generation passive optical network, and an optical network unit of a third-generation passive optical network.

[0043] In an embodiment of the present application, after the central office device OLT determines that the working wavelength of the first optical network unit conflicts with the wavelength of the target passive optical network, the wavelength conflict problem can be solved by replacing the first optical network unit with a second optical network unit whose working wavelength does not conflict with the wavelength of the target passive optical network, wherein the second optical network unit can be an optical network unit of a first-generation passive optical network, or an optical network unit of a second-generation passive optical network, or an optical network unit of a third-generation passive optical network, and resources can be saved.

[0044] For example, if the optical network unit of the current first-generation passive optical network does not conflict with the wavelength of the target passive optical network, the optical network unit does not need to be replaced. For another example, if the optical network unit of the current first-generation passive optical network conflicts with the wavelength of the target passive optical network, the optical network unit can be updated to an optical network unit of other first-generation passive optical networks or second-generation passive optical networks that conflict with the wavelength of the third-generation passive optical network. Alternatively, the optical network unit can be directly replaced with an optical network unit of the third-generation passive optical network.

[0045] In one implementation, when the central office device OLT does not support the function of the third-generation passive optical network, the second optical network unit is an optical network unit of the first-generation passive optical network and / or the second-generation passive optical network, that is, when the central office device OLT does not support the function of the third-generation passive optical network, the new optical network unit used is an optical network unit of the first-generation passive optical network or an optical network unit of the second-generation passive optical network that does not conflict with the wavelength of the third-generation passive optical network.

[0046] In an embodiment of the present application, after the central office device OLT determines that the working wavelength of the first optical network unit conflicts with the wavelength of the target passive optical network, and the central office device OLT does not support the function of the third-generation passive optical network, the first optical network unit can be replaced with a second optical network unit whose working wavelength does not conflict with the wavelength of the target passive optical network. The second optical network unit can optionally be an optical network unit of the first-generation passive optical network and / or the second-generation passive optical network, thereby avoiding replacement of the central office device OLT, further avoiding waste of resources, and saving costs.

[0047] Figure 5 A flowchart showing another wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown. Figure 5 , the method comprises the following steps:

[0048] Step 501, replacing the original optical module of the first generation passive optical network and / or the second generation passive optical network with the optical module of the central office equipment OLT with a filter device added on the receiving optical path;

[0049] Step 502, detecting the online status of the EPON optical network unit or 10G EPON optical network unit before and after replacing the central office equipment OLT optical module; replacing the offline EPON optical network unit or 10G EPON optical network unit with an EPON optical network unit or 10G EPON optical network unit that supports coexistence.

[0050] The added filtering device directly passes the uplink optical signal of coexistent wavelength and cuts off the uplink optical signal of non-coexistent wavelength, and the filtering device can be located at any position of the optical path between the optical fiber connector of the OLT optical module of the local end equipment and the receiver.

[0051] Figure 6 is a wavelength processing schematic diagram of a filtering device provided by an exemplary embodiment of the present application, see Figure 6, the filtering device is defined as: 1260-1280nm wavelength and 1290-1330nm wavelength are directly passed, and 1280-1290nm wavelength and 1330-1360nm wavelength are cut off. Among them, the 1280-1290nm wavelength conflicts with the 50G PON upstream wavelength and cannot coexist, and the 1330-1360nm wavelength conflicts with the 50G PON downstream wavelength and cannot coexist. After the above-mentioned filtering device is added inside the 10G EPON optical module, the upstream optical signal sent by the EPON or 10G EPON terminal working in the wavelength range of 1280-1290nm and 1330-1360nm cannot be received by the central office equipment OLT optical module and causes disconnection. In this case, the conflicting EPON or 10G EPON terminal is replaced with one of the wavelength non-conflicting EPON, 10G EPON or 50G PON terminals, so that the coexistence of EPON, 10G EPON and 50GPON can be achieved.

[0052] Optionally, when the wavelengths of EPON and 10GE PON do not conflict with the downstream wavelength of 50G PON, the optical signals of the wavelengths of EPON, 10G EPON and 50G PON are directly passed.

[0053] Optionally, when EPON, 10G EPON, and 50G PON use wavelength division multiplexing, the wavelengths of EPON and 10GE PON do not conflict with the upstream wavelength of 50G PON, and the optical signals of the wavelengths of the EPON, 10G EPON, and 50G PON are directly passed.

[0054] Optionally, when EPON, 10G EPON, and 50G PON use time division multiplexing, the wavelengths of EPON and 10GE PON do not conflict with the upstream wavelength of 50G PON, and the optical signals of the wavelengths of the EPON, 10G EPON, and 50G PON are directly passed. For example, when EPON, 10G EPON, and 50G PON use time division multiplexing, the optical signals of the wavelengths of 1340 to 1344 nm and the upstream wavelength combination transition band (such as 1330 to 1340 nm, 1344 to 1350 nm) are cut off, and the optical signals of other wavelengths (such as 1260 to 1330 nm, 1350 to 1360 nm) are directly passed.

[0055] Figure 7 A flowchart showing another wavelength conflict terminal detection method provided by an exemplary embodiment of the present application is shown. The method does not require replacement of the existing central office equipment OLT optical module. Figure 7 , the method comprises the following steps:

[0056] Step 701, adding a filtering device after the output interface of the optical module of the central office equipment OLT;

[0057] Step 702, detecting the online status of the EPON optical network unit or 10G EPON optical network unit before and after the filter device is added; replacing the offline EPON optical network unit or 10G EPON optical network unit with an EPON optical network unit or 10G EPON optical network unit that supports coexistence.

[0058] Optionally, the filtering device may be a fiber optic connector, a box filter, or a wavelength detection line card located in an OLT frame of the central office equipment.

[0059] Optionally, the filtering device may include an uplink and downlink optical signal separator, a non-coexistence wavelength filter and an uplink and downlink optical signal combiner. The uplink and downlink optical signal separator and combiner may be implemented by devices such as a circulator and a polarization multiplexer. The non-coexistence wavelength filter cuts off wavelengths that do not support coexistence and passes through wavelengths that support coexistence. For details, see Figure 6 The wavelength processing schematic diagram shown in the figure directly passes the optical signals with wavelengths of 1260-1280nm and the optical signals with wavelengths of 1290-1330nm, and cuts off the optical signals with wavelengths of 1280-1290nm and the optical signals with wavelengths of 1330-1360nm.

[0060] Optionally, when the wavelengths of EPON and 10GE PON do not conflict with the downstream wavelength of 50G PON, the optical signals of the wavelengths of EPON, 10G EPON and 50G PON are directly passed.

[0061] Optionally, when EPON, 10G EPON, and 50G PON use wavelength division multiplexing, the wavelengths of EPON and 10GE PON do not conflict with the upstream wavelength of 50G PON, and the optical signals of the wavelengths of the EPON, 10G EPON, and 50G PON are directly passed.

[0062] Optionally, when EPON, 10G EPON, and 50G PON use time division multiplexing, the wavelengths of EPON and 10GE PON do not conflict with the upstream wavelength of 50G PON, and the optical signals of the EPON, 10G EPON, and 50G PON wavelengths are directly passed.

[0063] The embodiments of the present application can realize the coexistence of EPON, 10G EPON, and 50G PON, maximize the use of existing EPON and 10G EPON terminal resources, and solve the problem of resource waste caused by upgrading the passive optical network when there is a wavelength conflict in the passive optical network.

[0064] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0065] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A filtering device using a passive optical network, characterized in that: include: The filtering device is arranged on an optical path of a passive optical network PON, and is used to pass an optical signal of a first wavelength and cut off an optical signal of a second wavelength, wherein the first wavelength includes: a wavelength at which the first passive optical network and the second passive optical network coexist, and the second wavelength includes: a wavelength at which the first passive optical network and the second passive optical network conflict.

2. The filtering device according to claim 1, characterized in that The first wavelength is different from a downstream wavelength of the second passive optical network.

3. The filtering device according to claim 2, characterized in that: In the case where the first passive optical network and the second passive optical network adopt wavelength division multiplexing, the first wavelength is different from the uplink wavelength of the second passive optical network.

4. The filtering device according to claim 1, characterized in that In the case where the first passive optical network and the second passive optical network adopt time division multiplexing, the first wavelength is the same as the uplink wavelength of the second passive optical network.

5. The filtering device according to any one of claims 1 to 4, characterized in that: The first passive optical network includes: a first generation passive optical network and / or a second generation passive optical network, and the second passive optical network includes: a third generation passive optical network.

6. The filtering device according to any one of claims 1 to 4, characterized in that: The filtering device is arranged between the optical fiber connector of the OLT optical module of the central office equipment and the receiver; The OLT optical module of the central office equipment is an optical module supporting the first generation passive optical network and / or the second generation passive optical network.

7. The filtering device according to any one of claims 1 to 4, characterized in that: The filtering device is arranged in the uplink receiving optical path of the OLT optical module of the central office equipment and is located after the output interface of the OLT optical module of the central office equipment.

8. The filtering device according to claim 7, characterized in that: The filtering device comprises one of the following: an optical fiber connector, a box filter, and a wavelength detection line card located in an OLT frame of a central office equipment.

9. The filtering device according to claim 7, characterized in that: The filtering device comprises: an uplink and downlink optical signal separator, a filter and an uplink and downlink optical signal combiner; wherein, The uplink and downlink optical signal separator and the uplink and downlink optical signal combiner are connected in series between the output interface of the OLT optical module of the central office device and the optical distribution network ODN interface of the OLT of the central office device; The filter has one end connected to the uplink and downlink optical signal separator and the other end connected to the uplink and downlink optical signal combiner, and is used to cut off the optical signal of the second wavelength.

10. A method for detecting a wavelength conflict terminal, characterized in that: Applied to a passive optical network system provided with the filtering device according to any one of claims 1 to 9, the method comprises: The central office equipment OLT detects that the first optical network unit connected to its PON port is working abnormally, wherein the first optical network unit includes: an optical network unit of a first-generation passive optical network and / or a second-generation passive optical network; The central office equipment OLT determines that the working wavelength of the first optical network unit conflicts with the wavelength of a target passive optical network, wherein the target passive optical network includes: a third generation passive optical network.

11. The method according to claim 10, characterized in that After the central office device OLT determines that the working wavelength of the first optical network unit conflicts with the wavelength of the target passive optical network, the method further includes: The first optical network unit is replaced with a second optical network unit whose working wavelength does not conflict with the wavelength of the target passive optical network, wherein the second optical network unit includes one of the following: an optical network unit of a first-generation passive optical network, an optical network unit of a second-generation passive optical network, and an optical network unit of a third-generation passive optical network.

12. The method according to claim 11, characterized in that In the case that the central office equipment OLT does not support the function of the third generation passive optical network, the second optical network unit is an optical network unit of the first generation passive optical network and / or the second generation passive optical network.

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