Method, apparatus, system and storage medium applied to PON system

Abstract

The present application discloses a method, device, system and storage medium applied to a PON system, belonging to the field of communications. The PON system includes a primary OLT, a standby OLT and at least one ONU. The primary OLT performs window ranging on at least one ONU through a first management channel, and the primary OLT and any ONU transmit service data through a first service channel. The method includes: the standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel. The standby OLT sends a ranging request to a first ONU through a second management channel, where the first ONU is one of the at least one ONU, and the second management channel is a channel between the standby OLT and the at least one ONU. The standby OLT obtains a distance parameter between the first ONU and the standby OLT according to the ranging response received from the first ONU on the second management channel. The present application can reduce the duration of service interruption.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular, to a method, apparatus, system, and storage medium applied to a PON system. Background Art

[0002] A passive optical network (PON) includes an optical line terminal (OLT), an optical splitter, and multiple optical network units (ONUs). The OLT includes a primary port and a standby port. The primary port communicates with the optical splitter through a first backbone link, and the standby port communicates with the optical splitter through a second backbone link. The optical splitter also communicates with each ONU.

[0003] The OLT uses the primary port to perform service transmission with each ONU on the primary link; when the primary link fails, the OLT switches the service to the standby port, measures the distance parameters between the standby port and each ONU, and uses the standby port to perform service transmission with each ONU on the standby link based on the measured distance parameters.

[0004] In the process of implementing this application, the inventors found that the prior art has at least the following problems:

[0005] After the OLT switches the service to the standby port, it takes a long time to measure the distance between the standby port and each ONU, and then service transmission can be performed based on the measured distance, resulting in too long a service interruption time. Summary of the Invention

[0006] This application provides a method, apparatus, system, and storage medium applied to a PON system to reduce the service interruption time length. The technical solution is as follows:

[0007] In a first aspect, this application provides a method applied to a PON system. The first PON system includes a primary optical line terminal OLT, a standby OLT, and at least one optical network unit ONU. The primary OLT performs window ranging on at least one ONU through a first management channel, and service data is transmitted between the primary OLT and any ONU through a first service channel. The standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel. The standby OLT sends a ranging request to a first ONU through a second management channel, where the first ONU is one of the at least one ONU, and the second management channel is a channel between the standby OLT and the at least one ONU. The standby OLT obtains the distance parameter between the first ONU and the standby OLT according to the ranging response received from the first ONU on the second management channel.

[0008] Since during the process of the primary OLT transmitting service data to each ONU through the first service channel, the standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel, and the standby OLT measures the distance parameters between itself and each ONU through the second management channel. In this way, the transmission of service data between the primary OLT and each ONU is not affected during ranging, and when the service is switched to the standby OLT, the standby OLT directly uses the measured distance parameters between the standby OLT and each ONU and transmits service data to each ONU through the second service channel, thereby enabling the service to be quickly switched to the standby OLT and avoiding long-term service interruption.

[0009] In a possible implementation, the standby OLT receives a ranging notification sent by the primary OLT, and the ranging notification is used to instruct the standby OLT to perform ranging. The standby OLT determines, according to the ranging notification, that the primary OLT stops sending a downstream signal on the first management channel. In this way, based on this ranging notification, the standby OLT can accurately determine that the primary OLT stops sending a downstream optical signal on the first management channel.

[0010] In another possible implementation, the standby OLT receives a ranging notification sent by the primary OLT, and the ranging notification is used to instruct the standby OLT to perform ranging. The standby OLT detects the upstream optical signal received through the second management channel, and when the intensity of the detected upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first management channel. When receiving the ranging notification, it also detects the intensity of the upstream optical signal received from the second management channel, and based on this intensity, it can more accurately determine that the primary OLT stops sending a downstream optical signal on the first management channel.

[0011] In another possible implementation, the primary OLT and the standby OLT are modules in a first OLT device. The primary OLT includes a first port of the first OLT device, and the standby OLT includes a second port of the first OLT device. The first management channel and the first service channel are carried on the link between the first port and at least one ONU, and the second management channel is carried on the link between the second port and at least one ONU.

[0012] In another possible implementation, the standby OLT measures the optical signal corresponding to the ranging response and determines the signal quality corresponding to the first ONU. In this way, the signal quality corresponding to each ONU can be measured, and based on the signal quality corresponding to each ONU, the state of the backbone link connected to the standby OLT can be accurately measured.

[0013] In another possible implementation, the signal quality includes the received optical power.

[0014] In another possible implementation, the standby OLT determines the status of the backbone link based on the signal quality corresponding to each ONU in at least one ONU, where the backbone link is the common part of the links between the standby OLT and each ONU. Since the status of the backbone link can be determined, when the status is a fault status, maintenance can be promptly prompted to ensure that the backbone link is normal when the service is switched to the standby OLT, guaranteeing that the service can be successfully switched to the standby OLT.

[0015] In another possible implementation, the standby OLT determines that the primary OLT stops transmitting service data with at least one ONU through the first service channel. The standby OLT transmits service data with at least one ONU through the second service channel based on the distance parameter between each ONU in at least one ONU and the standby OLT. Since the distance parameter between each ONU and the standby OLT has been obtained, when the primary OLT stops transmitting service data with at least one ONU through the first service channel, service data can be quickly transmitted with at least one ONU through the second service channel, significantly reducing the time required for service switching.

[0016] In another possible implementation, the standby OLT obtains the configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the standby OLT. The standby OLT separately sends the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is used to send service data through the second service channel within the transmission time slot corresponding to the first ONU. The standby OLT receives service data from the second service channel.

[0017] In another possible implementation, the standby OLT obtains the compensation delay based on the distance parameter between the standby OLT and the first ONU and the distance parameter between the primary OLT and the first ONU. The standby OLT adjusts the first reception window based on the compensation delay to obtain the second reception window. The first reception window is obtained based on the distance threshold corresponding to the primary OLT, and the distance threshold is greater than or equal to the maximum value of the distances between the primary OLT and each ONU. The standby OLT receives the service data sent by each ONU from the second service channel within the second reception window.

[0018] In another possible implementation, the standby OLT sends an OLT switching indication to each ONU in at least one ONU through the second service channel, and the OLT switching indication is used to instruct each ONU to transmit service data with the standby OLT through the second service channel.

[0019] In another possible implementation, the standby OLT detects the upstream optical signal received through the second service channel. When the standby OLT detects that the intensity of the upstream optical signal is lower than the first threshold, it determines that the primary OLT stops sending the downstream optical signal on the first service channel. In this way, by detecting the upstream optical signal received through the second service channel, it is possible to promptly discover that the primary OLT stops sending the downstream optical signal on the first service channel, enabling the standby OLT to promptly switch the service from the primary OLT.

[0020] In another possible implementation, the distance parameter for the standby OLT to communicate with the first ONU includes the equalization delay for the standby OLT to communicate with the first ONU. The standby OLT sends the equalization delay to the first ONU.

[0021] In another possible implementation, the standby OLT connects the communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with at least one ONU. In this way, a single standby OLT can be used as a backup for multiple different primary OLTs, increasing the flexibility of network deployment.

[0022] In another possible implementation, there is a communication connection between the standby OLT and the first interface of the optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and the second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and at least one ONU included in the second PON system. The standby OLT controls the optical router to connect the first interface and the second interface. In this way, through the optical router, a protected PON system structure is formed by the primary OLT and the standby OLT, increasing the flexibility of network deployment.

[0023] In a second aspect, the present application provides an apparatus for use in a PON system, which is configured to execute the method in the first aspect or any one of the possible implementations of the first aspect. Specifically, the apparatus includes units for executing the method in the first aspect or any one of the possible implementations of the first aspect.

[0024] In a third aspect, the present application provides an apparatus for use in a PON system. The apparatus includes a processor and a memory. Among them, the processor and the memory can be connected through an internal connection. The memory is used to store programs, and the processor is used to execute the programs in the memory, enabling the apparatus to complete the method in the first aspect or any possible implementation of the first aspect.

[0025] Fourthly, the present application provides a computer program product, which includes a computer program stored in a computer-readable storage medium, and the computer program is loaded by a processor to implement the method according to the first aspect or any possible implementation manner of the first aspect.

[0026] Fifthly, the present application provides a computer-readable storage medium for storing a computer program, and the computer program is loaded by a processor to execute the method according to the first aspect or any possible implementation manner of the first aspect.

[0027] Sixthly, the present application provides a chip, which includes a memory and a processor. The memory is used for storing computer instructions, and the processor is used for calling and running the computer instructions from the memory to execute the method according to the first aspect or any possible implementation manner of the first aspect.

[0028] Seventhly, the present application provides a PON system, which includes a primary optical line terminal OLT, a standby OLT, and at least one optical network unit ONU. The primary OLT performs window ranging on the at least one ONU through a first management channel, and transmits service data between the primary OLT and any ONU through a first service channel.

[0029] The primary OLT is configured to send a ranging notification to the standby OLT when stopping sending a downstream management signal on the first management channel, and the ranging notification is used to instruct the standby OLT to perform ranging. The standby OLT is configured to execute the method according to the first aspect or any possible implementation manner of the first aspect.

[0030] Since, during the process of the primary OLT transmitting service data to each ONU through the first service channel, when the primary OLT stops sending a downstream optical signal on the first management channel, it sends a ranging notification to the standby OLT, and the standby OLT measures the distance parameters between it and each ONU through a second management channel based on the ranging notification. In this way, the transmission of service data between the primary OLT and each ONU will not be affected during ranging, and when the service is switched to the standby OLT, the standby OLT directly uses the measured distance parameters between the standby OLT and each ONU to transmit service data to each ONU through a second service channel, so that the service can be quickly switched to the standby OLT, avoiding long-term service interruption.

[0031] In a possible implementation manner, the primary OLT is further configured to transmit service data to at least one ONU through the first service channel when stopping sending a downstream management signal on the first management channel. In this way, when the standby OLT performs ranging on the ONU, the primary OLT still uses the first service channel to transmit service data to at least one ONU, avoiding the occurrence of service interruption.

[0032] In a possible implementation, the primary OLT is used to periodically send ranging notifications to the standby OLT. Since the distance of the ONU may change, sending ranging notifications periodically enables the standby OLT to timely measure the distance parameters between the standby OLT and each ONU, ensuring the correctness of the distance parameters stored in the standby OLT.

[0033] In a possible implementation, a ranging notification is sent to the standby OLT when a new ONU goes online. This enables the standby OLT to timely measure the distance parameters between the standby OLT and the new ONU. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of a dual-homing protection PON system provided by an embodiment of the present application;

[0035] Figure 2 is a schematic structural diagram of another dual-homing protection PON system provided by an embodiment of the present application;

[0036] Figure 3 is a schematic structural diagram of a single-homing protection PON system provided by an embodiment of the present application;

[0037] Figure 4 is a schematic structural diagram of another single-homing protection PON system provided by an embodiment of the present application;

[0038] Figure 5 is a schematic structural diagram of a 1:N protection network provided by an embodiment of the present application;

[0039] Figure 6 is a flowchart of a method applied to a PON system provided by an embodiment of the present application;

[0040] Figure 7 is a flowchart of another method applied to a PON system provided by an embodiment of the present application;

[0041] Figure 8 is a schematic structural diagram of a device applied to a PON system provided by an embodiment of the present application;

[0042] Figure 9 is a schematic structural diagram of another device applied to a PON system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The following will further describe the embodiments of the present application in detail with reference to the drawings.

[0044] See Figure 1, The PON system 100 is a communication network that uses optical signals as the information transmission carrier. The PON system is a bidirectional optical access network that adopts a point-to-multipoint structure. The PON system includes an OLT located at the central office, an optical distribution network (ODN), and at least one ONU located on the user side. The OLT communicates with each ONU through the ODN. In the downstream direction, the signal sent by the OLT reaches each ONU through the ODN. For each ONU, the signal sent by the ONU reaches the OLT through the ODN.

[0045] Among them, the OLT includes ports. The ports on the OLT are connected to the ODN through the backbone link, and the ODN is connected to each ONU through the branch link. The link between the port on the OLT and the at least one ONU includes the backbone link between the port on the OLT and the ODN and the branch link between the ODN and the ONU.

[0046] The link between the port on the OLT and the at least one ONU is used to carry channels. The OLT sends downstream signals to the at least one ONU through this channel, and the at least one ONU sends upstream signals to the OLT through this channel.

[0047] In some embodiments, for the link between the port on the OLT and the at least one ONU, the channels carried on this link include two types of channels, namely the management channel and the service channel. The number of service channels may be one or more. The management channel and each service channel correspond to the same port on the OLT. This port includes the optical module corresponding to the management channel and the optical module corresponding to each service channel. The optical module corresponding to the management channel is used to send and / or receive signals on the management channel. The optical module corresponding to each service channel is used to send and / or receive signals on each service channel respectively.

[0048] In some embodiments, the optical module corresponding to the management channel includes a receiver and a transmitter, and the optical module corresponding to each service channel includes a receiver and a transmitter.

[0049] In some embodiments, the channels carried on this link are logical links established on this link. That is to say, the management channel and each service channel carried on this link are both logical links established on this link.

[0050] For any two channels in the management channel and each service channel, the two channels can be isolated by the optical wavelengths and / or frequencies corresponding to the signals transmitted on the two channels. For example, assuming that the two channels include a service channel and a management channel, the optical wavelength corresponding to the signal transmitted on the management channel is different from the optical wavelength corresponding to the signal transmitted on the service channel. And / or, the frequency corresponding to the signal transmitted on the management channel is different from the frequency corresponding to the signal transmitted on the service channel.

[0051] The optical wavelengths corresponding to the signals transmitted on the management channel include the optical wavelength corresponding to the first upstream signal and the optical wavelength corresponding to the first downstream signal, and the optical wavelength corresponding to the first upstream signal and the optical wavelength corresponding to the first downstream signal are two different optical signal wavelengths. The optical wavelengths corresponding to the signals transmitted on the service channel include the optical wavelength corresponding to the second upstream signal and the optical wavelength corresponding to the second downstream signal, and the optical wavelength corresponding to the second upstream signal and the optical wavelength corresponding to the second downstream signal are two different optical signal wavelengths.

[0052] The fact that the optical wavelength corresponding to the signal transmitted on the management channel is different from the optical wavelength corresponding to the signal transmitted on the service channel means that the optical wavelength corresponding to the first upstream signal transmitted on the management channel is different from the optical wavelength corresponding to the second upstream signal transmitted on the service channel, and that the optical wavelength corresponding to the first downstream signal transmitted on the management channel is different from the optical wavelength corresponding to the second downstream signal transmitted on the service channel.

[0053] For another example, assuming that the two channels include two service channels, the optical wavelengths corresponding to the signals transmitted on the two service channels are different, and / or, the frequencies corresponding to the signals transmitted on the two service channels are different.

[0054] The OLT is used to manage the at least one ONU through the management channel. For example, the OLT is used to perform ranging on each ONU in the at least one ONU through the management channel, and the management channel is used to transmit management data between the OLT and the at least one ONU. For example, when the OLT performs ranging on the first ONU, the first ONU is one of the at least one ONU, the OLT sends a ranging request to the first ONU on the management channel, the first ONU receives the ranging request, and sends a ranging response to the OLT on the management channel. The ranging request and the ranging response are management data transmitted between the OLT and the first ONU. And for the service channel between the OLT and the at least one ONU, the service channel is used to transmit service data between the OLT and the at least one ONU.

[0055] In a possible implementation, the OLT does not perform ranging on all ONUs within a window of a single window opening. The OLT sends ranging requests to some of the ONUs through the management channel within a window of a single window opening, avoiding the ranging responses of too many ONUs arriving at the OLT simultaneously, thereby avoiding conflicts among the ranging responses of multiple ONUs.

[0056] The management channel between the OLT and the at least one ONU can be a gigabit-capable passive optical networks (GPON) channel, an ethernet passive optical network (EPON) channel, a 10-gigabit symmetrical passive optical networks (XGS-PON) channel, etc. The service channel between the OLT and the at least one ONU can be an XGS-PON channel, a GPON channel, an EPON channel, etc. For example, when the management channel is a GPON channel, the service channel can be an EPON channel or an XGS-PON channel. Or, when the management channel is an EPON channel, the service channel can be a GPON channel or an XGS-PON channel. When the management channel is an XGS-PON channel, the service channel can be a GPON channel or an EPON channel.

[0057] In some embodiments, the above ODN includes one or more splitters. The above backbone link and branch link include optical fibers, etc. The above physical channel and service channel are logical channels.

[0058] PON protection technologies include single-homing protection technology and dual-homing protection technology.

[0059] See Figure 1 The PON system 100 implementing the dual-homing protection technology shown. The PON system 100 with dual-homing protection technology includes a primary OLT, a standby OLT, and at least one ONU. The primary OLT and the standby OLT are two different OLT devices. A first management channel and at least one first service channel are carried on the link between the primary OLT and the at least one ONU, and a second management channel and at least one second service channel are carried on the link between the standby OLT and the at least one ONU.

[0060] When the backbone link between the primary OLT and the ODN is normal, the primary OLT transmits service data to the at least one ONU through the at least one first service channel, and the primary OLT transmits management data to the at least one ONU through the first management channel. When the backbone link between the primary OLT and the ODN fails, the service is switched to the standby OLT. The standby OLT transmits service data to the at least one ONU through the at least one second service channel based on the distance parameters between the standby OLT and each ONU among the at least one ONU, and transmits management data to the at least one ONU through the second management channel. When the backbone link between the primary OLT and the ODN returns to normal, the service is switched to the primary OLT. The primary OLT transmits service data to the at least one ONU through the at least one first service channel based on the distance parameters between the primary OLT and each ONU among the at least one ONU, and transmits management data to the at least one ONU through the first management channel.

[0061] That is to say, before switching the service to the standby OLT, the standby OLT needs to measure the distance parameters between the standby OLT and each ONU. And before switching the service to the primary OLT, the primary OLT needs to measure the distance parameters between the primary OLT and each ONU.

[0062] For the above-mentioned first management channel and the at least one first service channel, the link through which the downstream signal sent by the primary OLT to the first ONU on the first management channel passes is the same as the link through which the downstream signal sent by the primary OLT to the first ONU on the at least one first service channel passes. The link through which the upstream signal sent by the first ONU to the primary OLT on the first management channel passes is the same as the link through which the upstream signal sent by the first ONU to the primary OLT on the at least one first service channel passes. Therefore, the distance parameter between the primary OLT and the first ONU measured by the primary OLT on the first management channel is equal to the distance parameter between the primary OLT and the first ONU measured by the primary OLT on any one of the first service channels, and both are equal to the distance parameter between the primary OLT and the first ONU.

[0063] Similarly, for the above-mentioned second management channel and at least one second service channel, the links through which the downlink signals sent by the standby OLT to the first ONU in the second management channel pass are the same as those through which the downlink signals sent by the standby OLT to the first ONU in the at least one second service channel pass. The links through which the uplink signals sent by the first ONU to the standby OLT in the second management channel pass are the same as those through which the uplink signals sent by the first ONU to the standby OLT in the at least one second service channel pass. Therefore, the distance parameter measured by the standby OLT between the standby OLT and the first ONU in the second management channel is equal to the distance parameter measured by the standby OLT between the standby OLT and the first ONU in any one of the second service channels, and both are equal to the distance parameter between the standby OLT and the first ONU.

[0064] Therefore, before switching the service to the standby OLT, the distance parameter between the standby OLT and each ONU can be measured through the second management channel; during the measurement process, the at least one first service channel is still used to transmit the service data between the active OLT and each ONU. And / or, before switching the service to the active OLT, the distance parameter between the active OLT and each ONU can be measured through the first management channel; during the measurement process, the at least one second service channel is still used to transmit the service data between the standby OLT and each ONU. This avoids affecting the transmission of service data.

[0065] See Figure 1 , the PON system 100 is a standard PON system architecture. The ODN in the PON system 100 includes a splitter, and the distance differences between each ONU and the active OLT and the standby OLT are equal, that is, the distance difference between the distance from the active OLT to the first ONU and the distance from the standby OLT to the first ONU is equal to the distance difference between the distance from the active OLT to the second ONU and the distance from the standby OLT to the second ONU. The second ONU is any ONU other than the first ONU among the at least one ONU. This results in the difference between the distance parameter of the active OLT and the first ONU and the distance parameter of the standby OLT and the first ONU being equal to the difference between the distance parameter of the active OLT and the second ONU and the distance parameter of the standby OLT and the second ONU. Or,

[0066] See Figure 2, the ODN in the PON system 100 includes multiple optical splitters. The distance differences between each ONU and the primary OLT and the standby OLT are not all equal. That is, the distance difference between the primary OLT and the first ONU and the distance difference between the standby OLT and the first ONU may not be equal to the distance difference between the primary OLT and the second ONU and the distance difference between the standby OLT and the second ONU. As a result, the difference between the distance parameters of the primary OLT and the first ONU and the distance parameters of the standby OLT and the first ONU may not be equal to the difference between the distance parameters of the primary OLT and the second ONU and the distance parameters of the standby OLT and the second ONU.

[0067] For example, refer to Figure 2 , the ODN includes a first optical splitter, a second optical splitter, a third optical splitter, and a fourth optical splitter. The primary OLT is connected to the first optical splitter through a first main link 11. The first optical splitter is connected to the third optical splitter through a first branch link 21. The first optical splitter is connected to the fourth optical splitter through a second branch link 22. The standby OLT is connected to the second optical splitter through a second main link 12. The second optical splitter is connected to the third optical splitter through a third branch link 23. The second optical splitter is connected to the fourth optical splitter through a fourth branch link 24. The third optical splitter is connected to ONU1 through a fifth branch link 31. The third optical splitter is connected to ONU2 through a sixth branch link 32. The fourth optical splitter is connected to ONU3 through a seventh branch link 33.

[0068] The distance from the primary OLT to ONU1 is equal to the sum of the length L11 of the first main link, the length L21 of the first branch link, and the length L31 of the fifth branch link, that is, L11 + L21 + L31. The distance from the standby OLT to ONU1 is equal to the sum of the length L12 of the second main link, the length L23 of the third branch link, and the length L31 of the fifth branch link, that is, L12 + L23 + L31. The distance difference between the distance from the primary OLT to ONU1 and the distance from the standby OLT to ONU1 is L12 + L23 - L11 - L21.

[0069] The distance from the primary OLT to ONU3 is equal to the cumulative value of the length L11 of the first backbone link, the length L22 of the second branch link, and the length L33 of the seventh branch link, that is, L11 + L22 + L33. The distance from the standby OLT to ONU3 is equal to the cumulative value of the length L12 of the second backbone link, the length L24 of the fourth branch link, and the length L33 of the seventh branch link, that is, L12 + L24 + L33. The distance difference between the distance from the primary OLT to ONU3 and the distance from the standby OLT to ONU3 is L12 + L24 - L11 - L23. Therefore, the distance difference L12 + L23 - L11 - L21 between the distance from the primary OLT to ONU1 and the distance from the standby OLT to ONU1 is not equal to the distance difference L12 + L24 - L11 - L23 between the distance from the primary OLT to ONU3 and the distance from the standby OLT to ONU3.

[0070] See Figure 3 The PON system 100 implementing the single-homing protection technology as shown. The PON system 100 implementing the single-homing protection technology includes a first OLT device and at least one ONU. The primary OLT and the standby OLT are modules in the first OLT device. The primary OLT includes the first port of the first OLT device, and the standby OLT includes the second port of the first OLT device. The first port is the primary port, and the second port is the standby port.

[0071] A first management channel and at least one first service channel are carried on the link between the first port and the at least one ONU. A second management channel and at least one second service channel are carried on the link between the second port and the at least one ONU.

[0072] When the backbone link between the first port and the ODN is normal, the first OLT device transmits service data to the at least one ONU through the at least one first service channel, and the first OLT device transmits management data to the at least one ONU through the first management channel. When the backbone link between the first port and the ODN fails, the first OLT device switches the service to the second port. Based on the distance parameters between the second port and each ONU in the at least one ONU, the first OLT device transmits service data to the at least one ONU through the at least one second service channel, and transmits management data to the at least one ONU through the second management channel. When the backbone link between the first port and the ODN returns to normal, the first OLT device switches the service to the first port. Based on the distance parameters between the first port and each ONU in the at least one ONU, the first OLT device transmits service data to the at least one ONU through the at least one first service channel, and transmits management data to the at least one ONU through the first management channel.

[0073] That is to say, before the first OLT device switches services to the second port, the first OLT device needs to measure the distance parameters between the second port and each ONU. Moreover, before the first OLT device switches services to the first port, the first OLT device needs to measure the distance parameters between the first port and each ONU.

[0074] For the above-mentioned first management channel and at least one first service channel, the link through which the downlink signal sent by the first OLT device to the first ONU on the first management channel passes is the same as the link through which the downlink signal sent by the first OLT device to the first ONU on the at least one first service channel passes. The link through which the uplink signal sent by the first ONU to the first OLT device on the first management channel passes is the same as the link through which the uplink signal sent by the first ONU to the first OLT device on the at least one first service channel passes. Therefore, the distance parameter between the first OLT device and the first ONU measured by the first OLT device on the first management channel is equal to the distance parameter between the first OLT device and the first ONU measured by the first OLT device on any one of the first service channels, and both are equal to the distance parameter between the first port and the first ONU.

[0075] Similarly, for the above-mentioned second management channel and at least one second service channel, the link through which the downlink signal sent by the first OLT device to the first ONU on the second management channel passes is the same as the link through which the downlink signal sent by the first OLT device to the first ONU on the at least one second service channel passes. The link through which the uplink signal sent by the first ONU to the first OLT device on the second management channel passes is the same as the link through which the uplink signal sent by the first ONU to the first OLT device on the at least one second service channel passes. Therefore, the distance parameter between the first OLT device and the first ONU measured by the first OLT device on the second management channel is equal to the distance parameter between the first OLT device and the first ONU measured by the first OLT device on any one of the second service channels, and both are equal to the distance parameter between the second port and the first ONU.

[0076] Therefore, before switching services to the second port, the distance parameters between the second port and each ONU can be measured through the second management channel; during the measurement process, the at least one first service channel is still used to transmit the service data between the first port and each ONU. And / or, before switching services to the first port, the distance parameters between the first port and each ONU can be measured through the first management channel; during the measurement process, the second service channel is still used to transmit the service data between the second port and each ONU. This avoids affecting the transmission of service data.

[0077] See Figure 3, the PON system 100 is a standard PON system architecture. The ODN in the PON system 100 includes a splitter. The distance difference between each ONU and the first port and the second port is equal, that is, the distance difference between the first port and the first ONU and the second port and the first ONU is equal to the distance difference between the first port and the second ONU and the second port and the second ONU. The second ONU is any ONU other than the first ONU among the at least one ONU. This results in the difference between the distance parameter between the first port and the first ONU and the distance parameter between the second port and the first ONU being equal to the difference between the distance parameter between the first port and the second ONU and the distance parameter between the second port and the second ONU. Or,

[0078] See Figure 4 , the ODN in the PON system 100 includes multiple splitters. The distance differences between each ONU and the first port and the second port are not all equal, that is, the distance difference between the first port and the first ONU and the second port and the first ONU may not be equal to the distance difference between the first port and the second ONU and the second port and the second ONU. This results in the difference between the distance parameter between the first port and the first ONU and the distance parameter between the second port and the first ONU may not be equal to the difference between the distance parameter between the first port and the second ONU and the distance parameter between the second port and the second ONU.

[0079] For example, see Figure 4 , the ODN includes a first splitter, a second splitter, a third splitter, and a fourth splitter. The first port is connected to the first splitter through a first main link 11. The first splitter is connected to the third splitter through a first branch link 21. The first splitter is connected to the fourth splitter through a second branch link 22. The second port is connected to the second splitter through a second main link 12. The second splitter is connected to the third splitter through a third branch link 23. The second splitter is connected to the fourth splitter through a fourth branch link 24. The third splitter is connected to ONU1 through a fifth branch link 31. The third splitter is connected to ONU2 through a sixth branch link 32. The fourth splitter is connected to ONU3 through a seventh branch link 33.

[0080] The distance between the first port and ONU1 is equal to the cumulative value of the length L11 of the first main link, the length L21 of the first branch link, and the length L31 of the fifth branch link, that is, L11 + L21 + L31. The distance between the second port and ONU1 is equal to the cumulative value of the length L12 of the second main link, the length L23 of the third branch link, and the length L31 of the fifth branch link, that is, L12 + L23 + L31. The distance difference between the distance from the first port to ONU1 and the distance from the second port to ONU1 is L12 + L23 - L11 - L21.

[0081] The distance between the first port and ONU3 is equal to the cumulative value of the length L11 of the first main link, the length L22 of the second branch link, and the length L33 of the seventh branch link, that is, L11 + L22 + L33. The distance between the second port and ONU3 is equal to the cumulative value of the length L12 of the second main link, the length L24 of the fourth branch link, and the length L33 of the seventh branch link, that is, L12 + L24 + L33. The distance difference between the distance from the first port to ONU3 and the distance from the second port to ONU3 is L12 + L24 - L11 - L23. Therefore, the distance difference L12 + L23 - L11 - L21 between the distance from the first port to ONU1 and the distance from the second port to ONU1 is not equal to the distance difference L12 + L24 - L11 - L23 between the distance from the first port to ONU3 and the distance from the second port to ONU3.

[0082] See Figure 5 , the standby OLT also communicates with the optical router, or, the standby OLT included in the first OLT device also communicates with the optical router, so as to form a 1:N protection network. N is an integer greater than or equal to 1. The protection network includes one standby OLT and N main OLTs. One main OLT is selected from the N main OLTs by the optical router, and the selected main OLT and the standby OLT form a PON system 100 with single-homing protection technology or a PON system 100 with dual-homing protection technology.

[0083] The optical router includes a first interface and multiple second interfaces. The standby OLT (or the standby OLT on the first OLT device) communicates with the first interface of the optical router. Each second interface of the optical router corresponds to an ODN. For any ODN, for the sake of convenience of description, this ODN is called the first ODN. The first ODN corresponds to a second interface on the optical router, and there is a communication connection between the first ODN and this second interface. The first ODN also communicates with one main OLT and at least one ONU.

[0084] When the optical router connects the first interface and the second interface, the standby OLT, the primary OLT communicating with the first ODN, and the at least one ONU form a PON system with single-homing protection technology or a PON system with dual-homing protection technology. Among them, when the standby OLT and the primary OLT communicating with the first ODN are two different OLT devices, the formed PON system is a PON system with dual-homing protection technology. When the standby OLT and the primary OLT communicating with the first ODN are two different modules on the first OLT device, the formed PON system is a PON system with single-homing protection technology.

[0085] See Figure 6 , this application provides a method 600 for applying a PON system. The PON system can be Figure 1 or Figure 2 the PON system 100 with dual-homing protection technology shown, or it can be Figure 3 or Figure 4 the PON system 100 with single-homing protection technology shown, or it can be a PON system combined by the optical router in Figure 5 . The PON system includes a primary OLT, a standby OLT, and at least one ONU. The primary OLT and the standby OLT communicate with the at least one ONU through the first ODN. The method 600 includes:

[0086] Step 601: The standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel.

[0087] The primary OLT periodically triggers the standby OLT to measure the distance parameters between the standby OLT and each ONU in the at least one ONU. Alternatively, when the primary OLT detects that a new ONU registers and goes online on the primary OLT, it triggers the standby OLT to measure the distance parameters between the standby OLT and each ONU in the at least one ONU.

[0088] When the primary OLT determines to trigger the standby OLT to measure the distance parameters between the standby OLT and each ONU, it stops sending a downstream optical signal on the first management channel.

[0089] In some embodiments, the primary OLT includes a first port. The first port includes the function of sending a downstream optical signal on the first management channel and the function of sending a downstream optical signal on at least one first service channel. The primary OLT turns off the function of sending a downstream optical signal on the first management channel included in the first port to stop sending a downstream optical signal on the first management channel.

[0090] In some embodiments, the primary OLT and the standby OLT are two modules on the first OLT device. Therefore, when the first OLT device disables the function of the primary OLT to send a downstream optical signal on the first management channel, it can be determined that the primary OLT stops sending the downstream optical signal on the first management channel.

[0091] In some embodiments, when the primary OLT and the standby OLT are two different devices, when the primary OLT stops sending a downstream optical signal on the first management channel, it sends a ranging notification to the standby OLT, and the ranging notification is used to instruct the standby OLT to perform ranging. For the message name of the ranging notification, this message name is only an example of the embodiments of the present application and can also be called other names, such as ranging indication, etc.

[0092] Thus, in step 601: The standby OLT receives the ranging notification sent by the primary OLT, and determines, according to the ranging notification, that the primary OLT stops sending a downstream signal on the first management channel. Alternatively, the standby OLT receives the ranging notification sent by the primary OLT, and according to the indication of the ranging notification, detects the upstream optical signal received through the second management channel. When the intensity of the detected upstream optical signal is lower than the first threshold, it is determined that the primary OLT stops sending a downstream signal on the first management channel.

[0093] The primary OLT sends a downstream optical signal to each ONU on the first management channel, and each ONU receives the downstream optical signal and sends an upstream optical signal on the first management channel in response to the downstream optical signal. After the primary OLT stops sending a downstream optical signal on the first management channel, each ONU will not send an upstream optical signal on the first management channel either.

[0094] Among them, the first management channel is carried on the link between the primary OLT and each ONU, and the second management channel is carried on the link between the standby OLT and each ONU. The link between the primary OLT and each ONU includes the backbone link between the primary OLT and the first ODN and the branch link between the first ODN and each ONU. The link between the standby OLT and each ONU includes the backbone link between the standby OLT and the first ODN and the branch link between the first ODN and each ONU. Therefore, when each ONU does not send an upstream optical signal on the first management channel, it will not send an upstream optical signal on the second management channel either. Therefore, the standby OLT detects the upstream optical signal received through the second management channel, and the intensity of the detected upstream optical signal is lower than the first threshold.

[0095] In some embodiments, before the primary OLT determines to trigger the standby OLT to measure the distance parameters between the standby OLT and each ONU, the standby OLT also detects the upstream optical signals received through the second management channel and / or the second service channel. If the intensity of the detected upstream optical signal is greater than or equal to the first threshold, it indicates that there is a link connection between the standby OLT and at least one ONU. If the intensity of the detected upstream optical signal is lower than the first threshold, it indicates that there may be no link connection between the standby OLT and at least one ONU, and then the technician is prompted to perform maintenance.

[0096] The primary OLT uses at least one first service channel to transmit service data with at least one ONU. During the process of transmitting service data, the at least one ONU will simultaneously send upstream optical signals on at least one first service channel and at least one second service channel, so that the standby OLT receives the upstream optical signals through the at least one second service channel. And,

[0097] Before the primary OLT determines to trigger the standby OLT to measure the distance parameters between the standby OLT and each ONU, the primary OLT transmits management data with the at least one ONU. During the process of transmitting management data, the at least one ONU will simultaneously send upstream optical signals on the first management channel and the second management channel, so that the standby OLT receives the upstream optical signals through the second management channel.

[0098] Before executing step 601, the standby OLT also controls the optical router to connect the communication connection between the standby OLT and the first ODN. In implementation: the standby OLT controls the optical router to connect the first interface and the second interface corresponding to the first ODN.

[0099] Since there is a communication connection between the standby OLT and the first interface of the optical router, and there is a communication connection between the first ODN and the second interface corresponding to the first ODN, connecting the first interface and the second interface corresponding to the first ODN enables the communication connection between the standby OLT and the first ODN to be connected. And the first ODN also communicates with a primary OLT and at least one ONU, so that the standby OLT, the primary OLT, and the at least one ONU form a PON system.

[0100] Among them, in the embodiments of the present application, the PON may be a PON with dual-homing protection technology, so the primary OLT and the standby OLT in the embodiments of the present application are two different OLT devices. Or, the PON may be a PON with single-homing protection technology, so the primary OLT and the standby OLT in the embodiments of the present application are two modules on the first OLT device.

[0101] Step 602: The standby OLT sends a ranging request to the first ONU through the second management channel, where the first ONU is one of the at least one ONU.

[0102] The standby OLT includes a second port, and the second port includes the function of sending a downstream optical signal on the second management channel and the function of sending a downstream optical signal on the second service channel. The standby OLT enables the function of sending a downstream optical signal on the second management channel included in the second port, and then the standby OLT sends a ranging request to the first ONU through the second management channel, and the ranging request is carried on the downstream optical signal.

[0103] In step 602, the standby OLT also obtains a first transmission timestamp, where the first transmission timestamp is the timestamp when the standby OLT sends the ranging request.

[0104] In some embodiments, the standby OLT includes a first timestamp counter, and when the standby OLT sends the ranging request, it reads the value counted by the first timestamp counter as the first transmission timestamp.

[0105] Before sending the ranging request to the first ONU, the standby OLT also sends a window opening indication to the first ONU through the second management channel, and the window opening indication is used to indicate a ranging window for ranging the first ONU. Within the ranging window, the standby OLT sends a ranging request to the first ONU through the second management channel.

[0106] After the standby OLT sends the window opening indication, each of the at least one ONU receives the window opening indication from the second management channel and determines a ranging window for ranging the first ONU based on the window opening indication. For other ONUs except the first ONU, the other ONUs do not send an upstream optical signal on the second management channel within the ranging window. And the first ONU communicates with the standby OLT through the second management channel within the ranging window.

[0107] In some embodiments, the window opening indication includes the identifier of the first ONU and the configuration information of the ranging window, so that the window opening indication is used to indicate a ranging window for ranging the first ONU. The configuration information includes the start time and end time of the ranging window, or the configuration information includes the start time and time length of the ranging window, or the configuration information includes the end time and time length of the ranging window, etc.

[0108] In some embodiments, after the standby OLT enables the function of sending a downstream optical signal on the second management channel included in the second port, each ONU is registered on the standby OLT through the second management channel. The registration process is as follows: The standby OLT sends a serial number request message to each of the at least one ONU through the second management channel. Each ONU receives the serial number request message and sends its respective serial number to the standby OLT through the second management channel. The standby OLT receives the serial numbers of each ONU, assigns an identifier to each ONU based on the serial number of each ONU, and sends the identifier of each ONU to each ONU respectively. Then, the operation in step 602 is performed.

[0109] In some embodiments, after the standby OLT enables the function of sending a downstream optical signal on the second management channel included in the second port, instead of performing the above registration process, the operation in step 602 is directly performed to perform ranging on each ONU.

[0110] It should be noted that: The primary OLT disables the function of sending a downstream optical signal on the first management channel included in the first port to stop sending the downstream optical signal on the first management channel. At this time, each ONU goes offline from the primary OLT on the first management channel. After the primary OLT stops sending the downstream optical signal on the first management channel and the standby OLT enables the function of sending a downstream optical signal on the second management channel included in the second port, at this time, the standby OLT enables each ONU to go online from the standby OLT through the second management channel through the above registration process. After the registration is successful, the standby OLT performs ranging on each ONU, that is, starts to perform the operation in step 602 to perform ranging on each ONU.

[0111] In some embodiments, after the standby OLT enables the function of sending a downstream optical signal on the second management channel included in the second port, each ONU is not enabled to go online from the standby OLT through the second management channel through the above registration process. Since each ONU has been registered on the primary OLT, the standby OLT obtains the identifier of each ONU from the primary OLT, and then performs the operation in step 602 to perform ranging on each ONU.

[0112] In some embodiments, the first ONU is a newly online ONU. That is to say, the standby OLT performs ranging on the newly online ONU. For the ONUs that have been ranged in the previous time, the standby OLT may no longer perform ranging on these ONUs. The standby OLT can query the newly online ONUs from the primary OLT, or the standby OLT receives the identifiers of the newly online ONUs sent by the primary OLT, or the standby OLT compares each currently registered ONU with each previously registered ONU to obtain the newly online ONUs.

[0113] Step 603: The first ONU receives the ranging request through the second management channel and sends a ranging response to the standby OLT through the second management channel.

[0114] The ranging response includes a second transmission timestamp and a first reception timestamp. The first reception timestamp is the timestamp when the first ONU receives the ranging request, and the second transmission timestamp is the timestamp when the first ONU sends the ranging response.

[0115] In some embodiments, the first ONU includes a second timestamp counter. When the first ONU receives the ranging request, it reads the value counted by the second timestamp counter as the first reception timestamp. When the first ONU determines to send the ranging response, it reads the value counted by the second timestamp counter as the second transmission timestamp.

[0116] Among them, the counting frequency of the first timestamp counter is the same as that of the second timestamp counter.

[0117] Step 604: The standby OLT obtains the distance parameter between the first ONU and the standby OLT according to the ranging response received from the first ONU on the second management channel.

[0118] In step 604, the standby OLT receives the ranging response sent by the first ONU from the second management channel, obtains the second reception timestamp, and the second reception timestamp is the timestamp when the ranging response is received. Based on the first transmission timestamp, the second transmission timestamp, the first reception timestamp, and the second reception timestamp, the distance parameter between the standby OLT and the first ONU is obtained.

[0119] In some embodiments, when the first ONU receives the ranging response, it reads the value counted by the first timestamp counter as the second reception timestamp.

[0120] In some embodiments, when the second management channel is a GPON channel, the distance parameter includes an equalization delay (EQD). When the second management channel is an EPON channel, the distance parameter includes a round-trip time (RTT).

[0121] In some embodiments, the standby OLT also measures the optical signal corresponding to the ranging response to determine the signal quality corresponding to the first ONU.

[0122] In some embodiments, the signal quality includes one or more of received optical power, received signal strength indication (RSSI), and optical signal strength, etc.

[0123] In some embodiments, the processes of steps 602 to 604 are respectively performed on each of the at least one ONU, so that the standby OLT obtains the distance parameters between the standby OLT and each ONU. Among them, since the environment where the ONU is located may change, which may cause the distance between the ONU and the standby ONU to change. Therefore, the standby OLT measures the distance parameters between the standby OLT and each ONU.

[0124] In some embodiments, when the above PON system is a standard PON system architecture as Figure 1 or Figure 3 shown, in this PON system, the distance differences between each ONU and the primary OLT and the standby OLT are equal. That is, the distance difference between the distance from the primary OLT to the first ONU and the distance from the standby OLT to the first ONU is equal to the distance difference between the distance from the primary OLT to the second ONU and the distance from the standby OLT to the second ONU, where the second ONU is any ONU other than the first ONU in this PON system. In this case, the standby OLT obtains the distance parameters between the primary OLT and each ONU, and performs ranging on the first ONU to obtain the distance parameters between the standby OLT and the first ONU. Based on the distance parameters between the primary OLT and the first ONU and the distance parameters between the standby OLT and the first ONU, the distance parameter difference is obtained. Based on this distance parameter difference and the distance parameters between the primary OLT and the second ONU, the distance parameters between the standby OLT and the second ONU are obtained. In this way, the standby OLT does not need to perform window ranging on each ONU, which not only reduces the resources required for ranging, but also quickly obtains the distance parameters between the standby OLT and each ONU, improving the ranging efficiency.

[0125] In some embodiments, when the primary OLT and the standby OLT are two different devices, the standby OLT obtains the distance parameters between the primary OLT and each ONU from the primary OLT.

[0126] In some embodiments, by performing the processes of steps 602 to 604, the standby OLT also obtains the signal quality corresponding to each ONU, and determines the state of the backbone link based on the signal quality corresponding to each ONU. The backbone link is the common part of the links between the standby OLT and each ONU.

[0127] In some embodiments, when the state of the backbone link is a fault state, the standby OLT prompts the technician to perform maintenance.

[0128] Among them, it should be noted that during the process of the standby OLT measuring the distance parameters between the standby OLT and each ONU using the second management channel, the primary OLT still transmits service data with each ONU through the first service channel. In this way, during the process of measuring the distance parameters between the standby OLT and each ONU, the transmission of service data will not be interrupted.

[0129] During the process of the standby OLT measuring the distance parameters between the standby OLT and each ONU using the second management channel, the primary OLT can also receive the upstream optical signal from the first management channel, but the primary OLT will not process this upstream optical signal.

[0130] In some embodiments, after obtaining the distance parameters between the standby OLT and the first ONU, the standby OLT saves the distance parameters between the standby OLT and the first ONU, and / or the standby OLT sends the distance parameters between the standby OLT and the first ONU to the first ONU, and the first ONU saves the distance parameters between the standby OLT and the first ONU.

[0131] In some embodiments, when both the first management channel and the second management channel are GPON channels, the distance parameters between the standby OLT and the first ONU include the equalization delay, and the standby OLT sends this equalization delay to the first ONU.

[0132] Among them, the actual distances between the standby OLT and each ONU may be different, resulting in different actual round-trip transmission delays between the standby OLT and each ONU. The standby OLT corresponds to a distance threshold, and this distance threshold is greater than or equal to the maximum value of the actual distances between the standby OLT and each ONU.

[0133] The first ONU receives the equalization delay between the standby OLT and the first ONU, and can compensate the actual round-trip transmission delay between the standby OLT and the first ONU based on this equalization delay. After compensation, the obtained round-trip transmission delay is equal to the round-trip transmission delay corresponding to this distance threshold. The round-trip transmission delay corresponding to this distance threshold refers to the round-trip transmission delay of the optical signal on the link with a length equal to this distance threshold. Each of the other ONUs is the same as the first ONU, and compensates the actual round-trip delay between itself and the standby OLT, so that the round-trip delay between the standby OLT and each ONU becomes the round-trip delay corresponding to this distance threshold.

[0134] The equalization delay between the standby OLT and the first ONU compensates for the actual round-trip transmission delay between the standby OLT and the first ONU, and can also be regarded as compensating for the actual distance between the standby OLT and the first ONU, obtaining the logical distance between the standby OLT and the first ONU, and this logical distance is equal to the distance threshold corresponding to the standby OLT. Therefore, the actual distance between the standby OLT and each ONU is compensated by the equalization delay between the standby OLT and each ONU, so that the logical distance between the standby OLT and each ONU is equal to the distance threshold corresponding to the standby OLT. Thus, the round-trip transmission delay between the standby OLT and each ONU is the same.

[0135] After the standby OLT measures the distance parameters between the standby OLT and each ONU, the standby OLT stops sending the downstream optical signal on the second management channel. Correspondingly, the active OLT sends the downstream optical signal on the first management channel to transmit management data with each ONU through the first management channel.

[0136] In some embodiments, the standby OLT realizes stopping sending the downstream optical signal on the second management channel by turning off the function of sending the downstream optical signal on the second port. The standby OLT realizes sending the downstream optical signal on the first management channel by turning on the function of sending the downstream optical signal on the first port.

[0137] Among them, in the case where the active OLT and the standby OLT are two different OLT devices, after the standby OLT measures the distance parameters between the standby OLT and each ONU, it sends a ranging completion notification to the active OLT. After receiving the ranging completion notification, the active OLT transmits management data with each ONU through the first management channel.

[0138] When the backbone link between the active OLT and the first ODN fails, at this time, the service needs to be switched from the active OLT to the standby OLT, and the operation of step 605 below is started. And / or, the technician switches the service from the active OLT to the standby OLT, and starts to execute the operation of step 605 below.

[0139] Step 605: The standby OLT determines that the active OLT stops transmitting service data with at least one ONU through the first service channel.

[0140] There is at least one first service channel between the active OLT and the at least one ONU, and there is at least one second service channel between the standby OLT and the at least one ONU.

[0141] When there is a first service channel between the primary OLT and the at least one ONU, and a second service channel between the standby OLT and the at least one ONU, in step 605, the standby OLT detects the upstream optical signal received through the second service channel; when the intensity of the detected upstream optical signal is lower than the first threshold, it is determined that the primary OLT stops sending the downstream optical signal on the first service channel.

[0142] When there are multiple first service channels between the primary OLT and the at least one ONU, and multiple second service channels between the standby OLT and the at least one ONU, in step 605, the standby OLT detects the upstream optical signals received through the multiple second service channels; when the intensity of the upstream optical signal on each second service channel is lower than the first threshold, it is determined that the primary OLT stops sending the downstream optical signals on the multiple first service channels.

[0143] During the process of the primary OLT and the at least one ONU transmitting service data, the primary OLT sends a downstream optical signal to each ONU on any one of the first service channels, and each ONU receives the downstream optical signal and sends an upstream optical signal on the any one of the first service channels in response to the downstream optical signal. After the primary OLT stops sending the downstream optical signal on the any one of the first service channels, each ONU will not send an upstream optical signal on the any one of the first service channels either.

[0144] Among them, the at least one first service channel is carried on the link between the primary OLT and each ONU, and the at least one second service channel is carried on the link between the standby OLT and each ONU. The link between the primary OLT and each ONU includes the backbone link between the primary OLT and the first ODN and the branch link between the first ODN and each ONU. The link between the standby OLT and each ONU includes the backbone link between the standby OLT and the first ODN and the branch link between the first ODN and each ONU. Therefore, each ONU will not send an upstream optical signal on the at least one first service channel and will not send an upstream optical signal on the at least one second service channel either. The standby OLT detects the upstream optical signal received through the at least one second service channel, and the intensity of the upstream optical signal on each detected second service channel is lower than the first threshold, so as to determine that the primary OLT stops sending the downstream optical signal on the at least one first service channel.

[0145] In some embodiments, when the standby OLT determines that the primary OLT stops transmitting service data to at least one ONU through at least one first service channel, the standby OLT sends an OLT handover indication to each ONU in the at least one ONU through any one of the second service channels. The OLT handover indication is used to instruct each ONU to transmit service data to the standby OLT through the at least one second service channel. Each ONU receives the OLT handover indication and prepares to use the distance parameter between itself and the standby OLT to transmit service data.

[0146] Step 606: The standby OLT transmits service data to each ONU in the at least one ONU through the second service channel.

[0147] In step 606, the standby OLT can transmit service data to each ONU in the at least one ONU in the following two ways. The two ways are as follows:

[0148] The first way: For any one of the at least one second service channels, the standby OLT transmits service data to the at least one ONU through the second service channel based on the distance parameter between each ONU in the at least one ONU and the standby OLT.

[0149] In some embodiments, when the second service channel is an EPON channel, the distance parameter between the standby OLT and each ONU is the equalized delay. The standby OLT can perform the following operations (1-1) to (1-3) to implement the first way. The operations (1-1) to (1-3) are as follows:

[0150] (1-1): The standby OLT obtains the configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the standby OLT.

[0151] In the operation of (1-1), the standby OLT allocates time slots for each ONU with the start time of the current transmission cycle as a reference, and the time slots corresponding to any two ONUs do not overlap. Based on the equalized delay between the standby OLT and each ONU, the time slots of each ONU are adjusted to obtain the transmission time slot corresponding to each ONU.

[0152] For example, assume that the time slot allocated by the standby OLT for the first ONU is the time period from t1 to t2, and the equalized delay between the standby OLT and the first ONU is Δt. The standby OLT adjusts the time slot of the first ONU to obtain the transmission time slot corresponding to the first ONU as the time period from Δt + t1 to Δt + t2.

[0153] For the transmission time slot corresponding to any one ONU, the configuration information of the transmission time slot includes the start time and the end time of the transmission time slot.

[0154] (1-2): The standby OLT sends the configuration information of the transmission time slot corresponding to each ONU to each ONU respectively through the second service channel.

[0155] In the operation of (1-2), the standby OLT sends the configuration information of the transmission time slot corresponding to each ONU to each ONU respectively at the start time of a transmission cycle. The standby OLT determines a reception window based on the distance threshold corresponding to the standby OLT, and the time difference between the start time of this reception window and the start time of this transmission cycle is determined based on the distance threshold corresponding to the standby OLT. The time length of this reception window is greater than or equal to the cumulative value of the time lengths of the transmission time slots corresponding to each ONU.

[0156] Among them, for each ONU in the at least one ONU, for example, still taking the first ONU as an example, the first ONU receives the configuration information of the transmission time slot corresponding to the first ONU from the second service channel, determines the transmission time slot corresponding to the first ONU based on this configuration information, and sends service data through the second service channel within the transmission time slot corresponding to the first ONU.

[0157] For each other ONU, each other ONU sends service data within its respective corresponding transmission time slot in the same way as the first ONU.

[0158] (1-3): The standby OLT receives service data from the second service channel.

[0159] The standby OLT receives the service data sent by each ONU from the second service channel within this reception window. Among them, each ONU sends service data within the transmission time slot corresponding to each ONU, and these service data will reach the standby OLT at different time periods and be received by the standby OLT. That is to say, the service data of each ONU will not conflict during transmission.

[0160] In some embodiments, when the second service channel is a GPON channel, the distance difference between the standby OLT and the first ONU and the distance difference between the active OLT and the first ONU is equal to the distance difference between the standby OLT and the second ONU and the distance difference between the active OLT and the second ONU, where the second ONU is any ONU other than the first ONU. That is to say, the first ODN is the standard ODN in the PON system as shown in Figure 1 or as shown in Figure 3 . The distance parameter between the standby OLT and each ONU is the round-trip delay. The standby OLT can adopt the following operations (2-1) to (2-3) to implement the first method. The operations of (2-1) to (2-3) are respectively:

[0161] (2-1): The standby OLT obtains the compensation delay based on the distance parameter between the standby OLT and the first ONU and the distance parameter between the active OLT and the first ONU.

[0162] When the standby OLT and the active OLT are two different modules on the first OLT device, the standby OLT (i.e., the first OLT device) includes the distance parameters between the active OLT and each ONU. When the standby OLT and the active OLT are two different OLT devices, the standby OLT previously receives the distance parameters between the active OLT and each ONU sent by the active OLT.

[0163] Similarly, for any ONU, that is, for the first ONU, the first ONU also includes the distance parameter between the active OLT and the first ONU.

[0164] It should be noted that the standby OLT allocates transmission time slots for each ONU with reference to the start time of the current transmission cycle, and the transmission time slots corresponding to any two ONUs do not overlap. The standby OLT sends the configuration information of the transmission time slot corresponding to each ONU to each ONU respectively through the second service channel at the start time of the transmission cycle.

[0165] The standby OLT also determines the first reception window based on the distance threshold corresponding to the active OLT. The time difference between the start time of the first reception window and the start time of the transmission cycle is determined based on the distance threshold corresponding to the active OLT. The time length of the first reception window is greater than or equal to the cumulative value of the time lengths of the transmission time slots corresponding to each ONU.

[0166] For the transmission time slot corresponding to any ONU, the configuration information of the transmission time slot includes the start time and the end time of the transmission time slot.

[0167] For any ONU, that is, for the first ONU, the first ONU receives the configuration information of the transmission time slot corresponding to the first ONU, determines its corresponding transmission time slot based on the configuration information, adjusts the transmission time slot based on the distance parameter between the first ONU and the active OLT, and sends service data through the second service channel within the adjusted transmission time slot.

[0168] For example, assume that the transmission time slots allocated by the standby OLT for the first ONU are in the time period from t1 to t2, and the distance parameter between the primary OLT and the first ONU is Δt, and the first ONU includes this distance parameter Δt. The first ONU receives the configuration information of the transmission time slots corresponding to the first ONU sent by the standby OLT, determines that the transmission time slots are in the time period from t1 to t2 based on this configuration information, and adjusts the transmission time slots based on Δt. The adjusted transmission time slots are in the time period from Δt + t1 to Δt + t2. Service data is sent through the second service channel within the adjusted transmission time slots.

[0169] (2-2): The standby OLT adjusts the first reception window based on the compensation time delay to obtain the second reception window.

[0170] Since each ONU adjusts the transmission time slots corresponding to each ONU using the distance parameter between itself and the primary OLT, and there is a distance difference between the distance from the primary OLT to any ONU and the distance from the standby OLT to that ONU, it is necessary to adjust the first reception window to obtain the second reception window.

[0171] (2-3): The standby OLT receives service data from the second service channel within the second reception window.

[0172] Among them, each ONU sends service data within the transmission time slots corresponding to each ONU. These service data will reach the standby OLT at different time periods and be received by the standby OLT. That is to say, there will be no conflict in the transmission of the service data of each ONU.

[0173] In the second method, for any one of the at least one second service channels, the standby OLT separately sends the distance parameter between the standby OLT and each ONU to each ONU. The standby OLT allocates transmission time slots for each ONU and sends the configuration information of the transmission time slots corresponding to each ONU to each ONU through the second service channel. Then, the standby OLT receives the service data sent by each ONU within the transmission time slots corresponding to each ONU through the second service channel.

[0174] If the distance parameter between the standby OLT and each ONU has been sent to each ONU when the distance parameter between the standby OLT and each ONU is measured, then in the second method, the standby OLT may not need to send the distance parameter.

[0175] In the second mode, the standby OLT assigns transmission time slots to each ONU with reference to the start time of the current transmission cycle, and there is no overlap between the transmission time slots corresponding to any two ONUs. At the start time of the transmission cycle, the standby OLT sends the configuration information of the transmission time slot corresponding to each ONU to each ONU respectively through the second service channel. The standby OLT also determines a reception window based on the distance threshold corresponding to the standby OLT, and the time length of the reception window is greater than or equal to the cumulative value of the time lengths of the transmission time slots corresponding to each ONU.

[0176] For any ONU, that is, for the first ONU, the first ONU receives the configuration information of the transmission time slot corresponding to the first ONU, and determines its corresponding transmission time slot based on the configuration information. Adjust the transmission time slot based on the distance parameter between the first ONU and the active OLT, and send service data through the second service channel within the adjusted transmission time slot. The standby OLT receives the service data sent by each ONU from the second service channel within the reception window.

[0177] In the embodiment of the present application, before the standby OLT uses the second service channel to transmit service data with each ONU, that is, before switching the service to the standby OLT, the active OLT stops sending the downstream optical signal on the first management channel. In this way, the standby OLT can measure the distance parameters between it and each ONU through the second management channel, and during the measurement process, the active OLT still uses the first service channel to transmit service data with the at least one ONU, avoiding affecting the service data transmission. When it is necessary to switch the service to the standby OLT, use the measured distance parameters between the standby OLT and each ONU to transmit service data with each ONU through the second service channel, so as to quickly switch the service to the standby OLT and avoid long-term service interruption.

[0178] See Figure 7 This application provides a method 700 for applying a PON system, and the PON system can be Figure 1 or Figure 2 the PON system 100 of the dual-homing protection technology shown, or can be Figure 3 or Figure 4 the PON system 100 of the single-homing protection technology shown, or can be through Figure 5A PON system composed of optical routers. The PON system includes a primary OLT, a standby OLT, and at least one ONU. The primary OLT and the standby OLT communicate with the at least one ONU through a first ODN. In this method, when the standby OLT transmits service data to each ONU through at least one second service channel, if the primary OLT detects that the backbone link connected to the primary OLT returns to normal, the service is switched to the primary OLT, so that the primary OLT transmits service data to each ONU through at least one first service channel. The method 700 includes:

[0179] Step 701: The primary OLT detects the upstream optical signal received through any one of the first service channels and / or the first management channel. When the intensity of the detected upstream optical signal exceeds the first threshold, perform the following step 702.

[0180] When the standby OLT transmits service data to the at least one ONU, each ONU in the at least one ONU sends an upstream optical signal through at least one first service channel and at least one second service channel.

[0181] The primary OLT detects the upstream optical signal received through any one of the first service channels and / or the first management channel. When the intensity of the detected upstream optical signal exceeds the first threshold, it means that an upstream optical signal can be received from any one of the first service channels and / or the first management channel, and the backbone link connected to the primary OLT may return to normal. The backbone link is the common part of the links between the primary OLT and each ONU.

[0182] When the primary OLT and the standby OLT are two different devices, the primary OLT sends a notification message to the standby OLT. The standby OLT receives the notification message and stops sending the downstream optical signal on the second management channel. When the primary OLT and the standby OLT are two modules on the first OLT device, when the first OLT device determines that the primary OLT receives an upstream optical signal from any one of the first service channels and / or the first management channel, it controls the standby OLT to stop sending the downstream optical signal on the second management channel.

[0183] Step 702: The primary OLT determines that the standby OLT stops sending the downstream optical signal on the second management channel.

[0184] For the detailed implementation process of the primary OLT determining that the standby OLT stops sending the downstream optical signal on the second management channel, refer to Figure 6 The relevant content of the standby OLT in step 601 of the method 600 shown, which will not be elaborated here.

[0185] Step 703: The active OLT sends a ranging request to the first ONU via the first management channel, where the first ONU is one of the at least one ONU.

[0186] For the detailed implementation process of the active OLT sending a ranging request to the first ONU, refer to the relevant content of the standby OLT in step 602 of the method 600 shown in Figure 6 and no further detailed description will be provided here.

[0187] Step 704: The first ONU receives the ranging request via the first management channel and sends a ranging response to the active OLT via the first management channel.

[0188] For the detailed implementation process of the first ONU sending a ranging response to the active OLT via the first management channel, refer to the relevant content of step 603 of the method 600 shown in Figure 6 and no further detailed description will be provided here.

[0189] Step 705: The active OLT obtains the distance parameter between the first ONU and the active OLT based on the ranging response received from the first ONU on the first management channel, and obtains the signal quality corresponding to the first ONU.

[0190] For the detailed implementation process of the active OLT obtaining the distance parameter between the first ONU and the active OLT and obtaining the signal quality corresponding to the first ONU, refer to the relevant content of the standby OLT in step 604 of the method 600 shown in Figure 6 and no further detailed description will be provided here.

[0191] In some embodiments, the active OLT obtains the distance parameters between the active OLT and each ONU and obtains the signal quality corresponding to each ONU by executing the processes of steps 703 - 705 above.

[0192] Step 706: The active OLT determines whether it has obtained the distance parameters between the active OLT and each of the at least one ONU and determines the state of the backbone link based on the signal quality corresponding to each ONU, where the backbone link is the common part of the links from the active OLT to each ONU.

[0193] The active OLT can determine the at least one ONU on which the standby OLT goes online. If the active OLT obtains the distance parameters between the active OLT and each of the at least one ONU, it means that each ONU can successfully go online on the active OLT. Then, determine whether the signal quality corresponding to each ONU exceeds the quality threshold. If all exceed the quality threshold, determine the state of the backbone link as the normal state; if not all exceed the quality threshold, determine the state of the backbone link as the abnormal state.

[0194] Step 707: When the primary OLT obtains the distance parameters between it and each of the at least one ONU and the status of the backbone link is normal, the primary OLT controls the standby OLT to stop transmitting service data to the at least one ONU through the second service channel.

[0195] Among them, when the primary OLT and the standby OLT are two different devices, the primary OLT sends a service cut-back instruction to the standby OLT. The standby OLT receives the service cut-back instruction and stops sending the downstream optical signal on at least one second service channel. That is, it stops transmitting service data to each ONU through at least one second service channel. When the primary OLT and the standby OLT are two modules on the first OLT device, the first OLT device directly controls the standby OLT to stop sending the downstream optical signal on at least one second service channel. Since each ONU does not receive the downstream optical signal on at least one second service channel, it will not respond to the downstream optical signal and send the upstream optical signal on at least one second service channel and at least one first service channel.

[0196] Step 708: The primary OLT determines that the standby OLT stops transmitting service data to the at least one ONU through the second service channel.

[0197] For the detailed implementation process of the primary OLT determining that the standby OLT stops transmitting service data to the at least one ONU through the second service channel, refer to Figure 6 the relevant content of the standby OLT in step 605 of the method 600 shown, which will not be elaborated here.

[0198] Step 709: The primary OLT transmits service data to each of the at least one ONU through the first service channel.

[0199] For the detailed implementation process of the primary OLT transmitting service data to each of the at least one ONU through the first service channel, refer to Figure 6 the relevant content of the standby OLT in step 606 of the method 600 shown, which will not be elaborated here.

[0200] In an embodiment of the present application, when the backbone link connected to the primary OLT returns to normal, the standby OLT stops sending a downstream optical signal on the second management channel. In this way, the primary OLT can measure the distance parameters between itself and each ONU and the signal quality corresponding to each ONU through the second management channel, and determine whether the backbone link is normal based on the signal quality corresponding to each ONU. During the measurement process, the standby OLT still uses the second service channel to transmit service data with the at least one ONU, avoiding affecting the transmission of service data. When the primary OLT determines that the backbone link is normal and can obtain the distance parameters between itself and each ONU, the primary OLT uses the distance parameters between the primary OLT and each ONU to transmit service data with each ONU through the first service channel, so as to quickly switch the service to the primary OLT and avoid long-term service interruption.

[0201] See Figure 8 , an embodiment of the present application provides a device 800 applied to a PON system. The first PON system includes a primary optical line terminal OLT. The device 800 and at least one optical network unit ONU. The primary OLT performs window ranging on the at least one ONU through the first management channel, and the primary OLT and any ONU transmit service data through the first service channel. The device 800 is deployed on the standby OLT of the PON system 100 as shown in Figures 1 to 5 , and the standby OLT in the method 600 as shown in Figure 6 . The device 800 includes:

[0202] A processing unit 801, configured to determine that the primary OLT stops sending a downstream optical signal on the first management channel;

[0203] A transceiver unit 802, configured to send a ranging request to a first ONU through the second management channel. The first ONU is one of the at least one ONU, and the second management channel is the channel between the device 800 and the at least one ONU;

[0204] The processing unit 801 is further configured to obtain the distance parameter between the first ONU and the device 800 according to the ranging response from the first ONU received by the transceiver unit 802 on the second management channel.

[0205] Optionally, for the detailed implementation process of the processing unit 801 to determine that the primary OLT stops sending a downstream optical signal on the first management channel, see the relevant content in step 601 of the method 600 as shown in Figure 6 , which will not be elaborated here.

[0206] Optionally, for the detailed implementation process of the processing unit 801 to obtain the distance parameter between the first ONU and the device 800, see the relevant content in Figure 6The relevant content in step 604 of the method 600 shown will not be elaborated here.

[0207] Optionally, the transceiver unit 803 is further configured to receive a ranging notification sent by the active OLT, where the ranging notification is used to instruct the device 800 to perform ranging.

[0208] The processing unit 801 is configured to determine, according to the ranging notification, that the active OLT stops sending a downstream signal on the first management channel.

[0209] Optionally, the transceiver unit 803 is further configured to receive a ranging notification sent by the active OLT, where the ranging notification is used to instruct the device 800 to perform ranging.

[0210] The processing unit 801 is configured to detect an upstream optical signal received through the second management channel, and when the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first management channel.

[0211] Optionally, for the detailed implementation process of the processing unit 801 to determine that the active OLT stops sending a downstream optical signal on the first management channel, refer to Figure 6 The relevant content in step 601 of the method 600 shown will not be elaborated here.

[0212] Optionally, the active OLT and the device 800 are modules in a first OLT device. The active OLT includes a first port of the first OLT device, and the device 800 includes a second port of the first OLT device. The first management channel and the first service channel are carried on the link between the first port and the at least one ONU, and the second management channel is carried on the link between the second port and the at least one ONU.

[0213] Optionally, the processing unit 801 is further configured to measure the optical signal corresponding to the ranging response and determine the signal quality corresponding to the first ONU.

[0214] Optionally, the signal quality includes the received optical power.

[0215] Optionally, the processing unit 801 is further configured to determine the state of the backbone link based on the signal quality corresponding to each ONU in the at least one ONU, where the backbone link is the common part of the links between the device 800 and each ONU.

[0216] Optionally, for the detailed implementation process of the processing unit 801 to determine the state of the backbone link, refer to Figure 6 The relevant content in step 604 of the method 600 shown will not be elaborated here.

[0217] Optionally, the processing unit 801 is further configured to determine that the active OLT stops transmitting service data to at least one ONU through the first service channel;

[0218] The transceiver unit 802 is configured to transmit service data to at least one ONU through the second service channel based on the distance parameter between each ONU in the at least one ONU and the device 800.

[0219] Optionally, for the detailed implementation process of the processing unit 801 determining that the active OLT stops transmitting service data to the at least one ONU through the first service channel, refer to Figure 6 the relevant content in step 605 of the method 600 shown in the figure, which will not be elaborated here.

[0220] Optionally, for the detailed implementation process of the transceiver unit 802 transmitting service data to at least one ONU through the second service channel, refer to Figure 6 the relevant content in step 606 of the method 600 shown in the figure, which will not be elaborated here.

[0221] Optionally, the processing unit 801 is further configured to obtain the configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the device 800;

[0222] The transceiver unit 802 is configured to separately send the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is configured to send service data through the second service channel within the transmission time slot corresponding to the first ONU; and receive the service data from the second service channel.

[0223] Optionally, for the detailed implementation process of the transceiver unit 802 obtaining the configuration information of the transmission time slot corresponding to each ONU, refer to Figure 6 the relevant content in step 606 of the method 600 shown in the figure, which will not be elaborated here.

[0224] Optionally, the processing unit 801 is further configured to obtain a compensation delay based on the distance parameter between the device 800 and the first ONU and the distance parameter between the active OLT and the first ONU;

[0225] The processing unit 801 is further configured to adjust the first reception window based on the compensation delay to obtain a second reception window, where the first reception window is obtained based on the distance threshold corresponding to the active OLT, and the distance threshold is greater than or equal to the maximum value among the distances between the active OLT and each ONU;

[0226] The transceiver unit 802 is configured to receive the service data sent by each ONU from the second service channel within the second reception window.

[0227] Optionally, for the detailed implementation process of the transceiver unit 802 to obtain the compensation delay and adjust the first reception window, refer to Figure 6 the relevant content in step 606 of the method 600 shown in FIG., which will not be elaborated herein.

[0228] Optionally, the transceiver unit 802 is further configured to send an OLT handover indication to each of the at least one ONU through a second service channel, where the OLT handover indication is used to instruct each ONU to transmit service data with the device 800 through the second service channel.

[0229] Optionally, the processing unit 801 is further configured to:

[0230] detect an upstream optical signal received through the second service channel;

[0231] when the intensity of the detected upstream optical signal is lower than a first threshold, determine that the primary OLT stops sending a downstream optical signal on the first service channel.

[0232] Optionally, the distance parameter for the device 800 to communicate with the first ONU includes the equalization delay for the device 800 to communicate with the first ONU, and the transceiver unit 802 is further configured to send the equalization delay to the first ONU.

[0233] Optionally, the processing unit 801 is further configured to connect the communication connection between the device 800 and the first optical distribution network ODN. There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

[0234] Optionally, there is a communication connection between the device 800 and a first interface of an optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and a second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and at least one ONU included in the second PON system;

[0235] The processing unit 801 is configured to control the optical router to connect the first interface and the second interface.

[0236] In the embodiment of the present application, during the process of the primary OLT transmitting service data to each ONU through the first service channel, the processing unit determines that the primary OLT stops transmitting the downstream optical signal on the first management channel, and measures the distance parameters between the primary OLT and each ONU through the second management channel. In this way, the transmission of service data between the primary OLT and each ONU will not be affected during ranging. Moreover, when the service is switched to the device, the transceiver unit directly uses the measured distance parameters between the standby OLT and each ONU, and transmits service data to each ONU through the second service channel, so that the service can be quickly switched to the device, avoiding long-term service interruption.

[0237] See Figure 9 , the embodiment of the present application provides a schematic diagram of a device 900 for measuring the link state. The device 900 may be the standby OLT in the PON system 100 shown above Figures 1 - 5 , or the standby OLT in the method 600 shown above Figure 6 . The device 900 includes at least one processor 901, an internal connection 902, and at least one port 903.

[0238] The device 900 is a device with a hardware structure and can be used to implement Figure 8 the functional modules in the device 800 described above. For example, those skilled in the art can think that Figure 8 the processing unit 801 in the device 800 shown above can be implemented by the at least one processor 901, Figure 8 and the transceiver unit 802 in the device 800 shown above can be implemented by the at least one port 903.

[0239] Optionally, the device 900 can also be used to implement the functions of the standby OLT in any of the above embodiments.

[0240] Optionally, the at least one port 903 includes the second port on the standby OLT.

[0241] Optionally, the above-mentioned processor 901 may be a hardware circuit, a general-purpose central processing unit (CPU), a network processor (NP), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the solution of the present application.

[0242] Optionally, see Figure 9 , when the above-mentioned processor 901 is a CPU or a microprocessor, etc., the device 900 further includes a memory 904, Figure 8The processing unit 801 in the illustrated apparatus 800 may be implemented by the at least one processor 901 invoking the code in the memory 904.

[0243] The above internal connection 902 may include a path for transmitting information between the above components. Optionally, the internal connection 902 is a single board or a bus, etc.

[0244] The above at least one port 903 is used to communicate with other devices or communication networks.

[0245] The above memory 904 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or may also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor through a bus. The memory may also be integrated with the processor.

[0246] Among them, the memory 904 is used to store the application program code for implementing the solution of this application and is controlled by the processor 901 to execute. The processor 901 is used to execute the application program code stored in the memory 904 and cooperate with the at least one port 903, so that the apparatus 900 implements the functions in this patent method.

[0247] In a specific implementation, as an embodiment, the processor 901 may include one or more CPUs, such as Figure 9 CPU0 and CPU1 in

[0248] In a specific implementation, as an embodiment, the apparatus 900 may include multiple processors, such as Figure 9 processor 901 and processor 907 in These processors may each be a single-CPU processor or a multi-CPU processor. Here, the processor may refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions).

[0249] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned storage medium can be a read-only memory, a disk, an optical disc, etc.

[0250] The above are only alternative embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included within the protection scope of the present application.

Claims

1. A method applied to a PON system, characterized in that, The first PON system includes a primary optical line terminal OLT, a standby OLT, and at least one optical network unit ONU. The primary OLT performs window ranging on the at least one ONU through a first management channel. Business data is transmitted between the primary OLT and any ONU through a first service channel. The method includes: The standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel; The standby OLT sends a ranging request to a first ONU through a second management channel. The first ONU is one of the at least one ONU. The second management channel is a channel between the standby OLT and the at least one ONU; The standby OLT obtains a distance parameter between the first ONU and the standby OLT according to the ranging response received from the first ONU on the second management channel. The distance parameter is used for the standby OLT to transmit business data with the at least one ONU through a second service channel. The second service channel has a different optical wavelength and / or frequency corresponding to the signal transmitted on the second management channel.

2. The method according to claim 1, wherein The standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel, including: The standby OLT receives a ranging notification sent by the primary OLT. The ranging notification is used to instruct the standby OLT to perform ranging; The standby OLT determines that the primary OLT stops sending a downstream signal on the first management channel according to the ranging notification.

3. The method according to claim 1, wherein The standby OLT determines that the primary OLT stops sending a downstream optical signal on the first management channel, including: The standby OLT receives a ranging notification sent by the primary OLT. The ranging notification is used to instruct the standby OLT to perform ranging; The standby OLT detects an upstream optical signal received through the second management channel. When the intensity of the detected upstream optical signal is lower than a first threshold, it is determined that the primary OLT stops sending a downstream optical signal on the first management channel.

4. The method according to any one of claims 1-3, characterized in that, The primary OLT and the standby OLT are modules in a first OLT device. The primary OLT includes a first port of the first OLT device, and the standby OLT includes a second port of the first OLT device. The first management channel and the first service channel are carried on the link between the first port and the at least one ONU, and the second management channel is carried on the link between the second port and the at least one ONU.

5. The method according to any one of claims 1 to 3, characterized in that, The method further includes: The standby OLT measures the optical signal corresponding to the ranging response and determines the signal quality corresponding to the first ONU.

6. The method according to claim 4, wherein The method further includes: The standby OLT measures the optical signal corresponding to the ranging response and determines the signal quality corresponding to the first ONU.

7. The method according to claim 5, wherein The signal quality includes received optical power.

8. The method according to claim 6, wherein The signal quality includes received optical power.

9. The method according to claim 5, wherein The method further includes: The standby OLT determines the status of the backbone link based on the signal quality corresponding to each of the at least one ONU, where the backbone link is the common part of the links between the standby OLT and each of the ONUs.

10. The method according to any one of claims 6 - 8, characterized in that, The method further includes: The standby OLT determines the status of the backbone link based on the signal quality corresponding to each of the at least one ONU, where the backbone link is the common part of the links between the standby OLT and each of the ONUs.

11. The method according to any one of claims 1-3, 6-9, characterized in that, After the standby OLT obtains the distance parameter for the communication between the first ONU and the standby OLT, the method further includes: The standby OLT determines that the primary OLT stops transmitting service data to the at least one ONU through the first service channel. The standby OLT transmits service data to the at least one ONU through a second service channel based on the distance parameter between each of the at least one ONU and the standby OLT.

12. The method according to claim 4, wherein After the standby OLT obtains the distance parameter for the communication between the first ONU and the standby OLT, the method further includes: The standby OLT determines that the primary OLT stops transmitting service data to the at least one ONU through the first service channel. The standby OLT transmits service data to the at least one ONU through a second service channel based on the distance parameter between each of the at least one ONU and the standby OLT.

13. The method according to claim 5, characterized in that After the standby OLT obtains the distance parameter for the communication between the first ONU and the standby OLT, the method further includes: The standby OLT determines that the primary OLT stops transmitting service data to the at least one ONU through the first service channel. The standby OLT transmits service data to the at least one ONU through a second service channel based on the distance parameter between each of the at least one ONU and the standby OLT.

14. The method according to claim 10, wherein After the standby OLT obtains the distance parameter for the communication between the first ONU and the standby OLT, the method further includes: The standby OLT determines that the primary OLT stops transmitting service data to the at least one ONU through the first service channel. The standby OLT transmits service data to the at least one ONU through a second service channel based on the distance parameter between each of the at least one ONU and the standby OLT.

15. The method according to claim 11, wherein The standby OLT transmits service data to the at least one ONU through a second service channel based on the distance parameter between each of the at least one ONU and the standby OLT, including: The standby OLT obtains the configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the standby OLT. The standby OLT separately sends the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is used to send service data through the second service channel within the transmission time slot corresponding to the first ONU. The standby OLT receives the service data from the second service channel.

16. The method according to any one of claims 12-14, characterized in that, The standby OLT transmits service data with the at least one ONU via the second service channel based on the distance parameter between each ONU in the at least one ONU and the standby OLT, including: The standby OLT obtains the configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the standby OLT. The standby OLT separately sends the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is used to send service data via the second service channel within the transmission time slot corresponding to the first ONU. The standby OLT receives the service data from the second service channel.

17. The method according to claim 11, wherein The standby OLT transmits service data with the at least one ONU via the second service channel based on the distance parameter between each ONU in the at least one ONU and the standby OLT, including: The standby OLT obtains a compensation delay based on the distance parameter between the standby OLT and the first ONU and the distance parameter between the active OLT and the first ONU. The standby OLT adjusts the first reception window based on the compensation delay to obtain a second reception window, where the first reception window is obtained based on the distance threshold corresponding to the active OLT, and the distance threshold is greater than or equal to the maximum value among the distances between the active OLT and each ONU. The standby OLT receives the service data sent by each ONU from the second service channel within the second reception window.

18. The method according to any one of claims 12-14, characterized in that, The standby OLT transmits service data with the at least one ONU via the second service channel based on the distance parameter between each ONU in the at least one ONU and the standby OLT, including: The standby OLT obtains a compensation delay based on the distance parameter between the standby OLT and the first ONU and the distance parameter between the active OLT and the first ONU. The standby OLT adjusts the first reception window based on the compensation delay to obtain a second reception window, where the first reception window is obtained based on the distance threshold corresponding to the active OLT, and the distance threshold is greater than or equal to the maximum value among the distances between the active OLT and each ONU. The standby OLT receives the service data sent by each ONU from the second service channel within the second reception window.

19. The method according to claim 11, wherein Before transmitting service data with the at least one ONU via the second service channel, the method further includes: The standby OLT sends an OLT switch indication to each ONU in the at least one ONU via the second service channel, where the OLT switch indication is used to indicate that each ONU transmits service data with the standby OLT via the second service channel.

20. The method according to any one of claims 12-15 and 17, characterized in that, Before transmitting service data with the at least one ONU via the second service channel, the method further includes: The standby OLT sends an OLT handover indication to each of the at least one ONUs through the second service channel, and the OLT handover indication is used to instruct each of the ONUs to transmit service data with the standby OLT through the second service channel.

21. The method according to claim 16, wherein Before transmitting service data with the at least one ONU through the second service channel, the method further includes: The standby OLT sends an OLT handover indication to each of the at least one ONUs through the second service channel, and the OLT handover indication is used to instruct each of the ONUs to transmit service data with the standby OLT through the second service channel.

22. The method according to claim 18, wherein Before transmitting service data with the at least one ONU through the second service channel, the method further includes: The standby OLT sends an OLT handover indication to each of the at least one ONUs through the second service channel, and the OLT handover indication is used to instruct each of the ONUs to transmit service data with the standby OLT through the second service channel.

23. The method according to claim 11, wherein The method further includes: The standby OLT detects an upstream optical signal received through the second service channel; When the standby OLT detects that the intensity of the upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first service channel.

24. The method according to any one of claims 12-15, 17, 19, 21, 22, characterized in that, The method further includes: The standby OLT detects an upstream optical signal received through the second service channel; When the standby OLT detects that the intensity of the upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first service channel.

25. The method according to claim 16, wherein The method further includes: The standby OLT detects an upstream optical signal received through the second service channel; When the standby OLT detects that the intensity of the upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first service channel.

26. The method according to claim 18, wherein The method further includes: The standby OLT detects an upstream optical signal received through the second service channel; When the standby OLT detects that the intensity of the upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first service channel.

27. The method according to claim 20, wherein The method further includes: The standby OLT detects an upstream optical signal received through the second service channel; When the standby OLT detects that the intensity of the upstream optical signal is lower than a first threshold, it determines that the primary OLT stops sending a downstream optical signal on the first service channel.

28. The method according to any one of claims 1-3, 6-9, characterized in that, The distance parameter for the standby OLT to communicate with the first ONU includes the equalization delay for the standby OLT to communicate with the first ONU, and the method further includes: The standby OLT sends the equalization delay to the first ONU.

29. The method according to claim 4, wherein The distance parameter for the standby OLT to communicate with the first ONU includes the equalization delay for the standby OLT to communicate with the first ONU, and the method further includes: The standby OLT sends the equalization delay to the first ONU.

30. The method according to claim 5, characterized in that The distance parameter for communication between the standby OLT and the first ONU includes the equalized delay of communication between the standby OLT and the first ONU, and the method further includes: The standby OLT sends the equalized delay to the first ONU.

31. The method according to claim 10, wherein The distance parameter for communication between the standby OLT and the first ONU includes the equalized delay of communication between the standby OLT and the first ONU, and the method further includes: The standby OLT sends the equalized delay to the first ONU.

32. The method according to any one of claims 1-3, 6-9, 12-15, 17, 19, 21-23, 25-27, 29-31, characterized in that, The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

33. The method according to claim 4, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

34. The method according to claim 5, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

35. The method according to claim 10, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

36. The method according to claim 11, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

37. The method according to claim 16, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

38. The method according to claim 18, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

39. The method according to claim 20, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

40. The method according to claim 24, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

41. The method according to claim 28, wherein The method further includes: The standby OLT establishes a communication connection between the standby OLT and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

42. The method according to claim 32, characterized in that, There is a communication connection between the standby OLT and the first interface of the optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and the second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and the at least one ONU included in the second PON system. The standby OLT establishing the communication connection between the standby OLT and the first optical distribution network (ODN) includes: The standby OLT controls the optical router to connect the first interface and the second interface.

43. The method according to any one of claims 33-41, wherein there is a communication connection between the standby OLT and the first interface of the optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and the second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and the at least one ONU included in the second PON system. The standby OLT establishing the communication connection between the standby OLT and the first optical distribution network (ODN) includes: The standby OLT controls the optical router to connect the first interface and the second interface.

44. A device applied to a PON system, characterized in that, The first PON system includes a primary optical line terminal (OLT), a standby OLT, and at least one optical network unit (ONU). The device is deployed on the standby OLT. The primary OLT performs window ranging on the at least one ONU through a first management channel, and business data is transmitted between the primary OLT and any ONU through a first service channel. The device includes: a processing unit configured to determine that the primary OLT stops sending a downstream optical signal on the first management channel; a transceiver unit configured to send a ranging request to a first ONU through a second management channel, where the first ONU is one of the at least one ONU, and the second management channel is a channel between the device and the at least one ONU; The processing unit is further configured to obtain a distance parameter between the first ONU and the device according to a ranging response from the first ONU received by the transceiver unit on the second management channel, where the distance parameter is used for the device to transmit service data with the at least one ONU through a second service channel, and the optical wavelength and / or frequency of the second service channel is different from that of the signal transmitted on the second management channel.

45. The device according to claim 44, wherein the transceiver unit is further configured to receive a ranging notification sent by the active OLT, where the ranging notification is used to instruct the device to perform ranging; the processing unit is configured to determine, according to the ranging notification, that the active OLT stops sending a downstream signal on the first management channel.

46. The device according to claim 44, wherein the transceiver unit is further configured to receive a ranging notification sent by the active OLT, where the ranging notification is used to instruct the device to perform ranging; the processing unit is configured to detect an upstream optical signal received through the second management channel, and when the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first management channel.

47. The device according to any one of claims 44-46, characterized in that, The active OLT and the device are modules in a first OLT device. The active OLT includes a first port of the first OLT device, and the device includes a second port of the first OLT device. The first management channel and the first service channel are carried on a link between the first port and the at least one ONU, and the second management channel is carried on a link between the second port and the at least one ONU.

48. The device according to any one of claims 44 to 46, characterized in that The processing unit is further configured to measure an optical signal corresponding to the ranging response and determine a signal quality corresponding to the first ONU.

49. The device according to claim 47, wherein, The processing unit is further configured to measure an optical signal corresponding to the ranging response and determine a signal quality corresponding to the first ONU.

50. The device according to claim 48, characterized in that, The signal quality includes received optical power.

51. The device according to claim 49, characterized in that, The signal quality includes received optical power.

52. The apparatus according to claim 48, characterized in that, The processing unit is further configured to determine a state of a backbone link based on the signal quality corresponding to each ONU in the at least one ONU, where the backbone link is a common part of the links between the device and each ONU.

53. The device according to any one of claims 49 - 51, characterized in that, The processing unit is further configured to determine a state of a backbone link based on the signal quality corresponding to each ONU in the at least one ONU, where the backbone link is a common part of the links between the device and each ONU.

54. The device according to any one of claims 44-46, 49-52, characterized in that, The processing unit is further configured to determine that the active OLT stops transmitting service data with the at least one ONU through the first service channel; the transceiver unit is further configured to transmit service data with the at least one ONU through a second service channel based on the distance parameter between each ONU in the at least one ONU and the device.

55. The device according to claim 47, characterized in that, The processing unit is further configured to determine that the active OLT stops transmitting service data with the at least one ONU through the first service channel; The transceiver unit is further configured to transmit service data with the at least one ONU through a second service channel based on the distance parameter between each ONU in the at least one ONU and the device.

56. The device according to claim 48, characterized in that, The processing unit is further configured to determine that the primary OLT stops transmitting service data with the at least one ONU through the first service channel. The transceiver unit is further configured to transmit service data with the at least one ONU through a second service channel based on the distance parameter between each ONU in the at least one ONU and the device.

57. The device according to claim 53, characterized in that, The processing unit is further configured to determine that the primary OLT stops transmitting service data with the at least one ONU through the first service channel. The transceiver unit is further configured to transmit service data with the at least one ONU through a second service channel based on the distance parameter between each ONU in the at least one ONU and the device.

58. The device according to claim 54, characterized in that, The processing unit is further configured to obtain configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the device. The transceiver unit is configured to separately send the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is configured to send service data through the second service channel within the transmission time slot corresponding to the first ONU; and receive the service data from the second service channel.

59. The device according to any one of claims 55 to 57, characterized in that, The processing unit is further configured to obtain configuration information of the transmission time slot corresponding to each ONU based on the distance parameter between each ONU and the device. The transceiver unit is configured to separately send the configuration information of the transmission time slot corresponding to each ONU to each ONU, where the first ONU is configured to send service data through the second service channel within the transmission time slot corresponding to the first ONU; and receive the service data from the second service channel.

60. The apparatus according to claim 54, wherein, The processing unit is further configured to obtain a compensation delay based on the distance parameter between the device and the first ONU and the distance parameter between the primary OLT and the first ONU. The processing unit is further configured to adjust a first reception window based on the compensation delay to obtain a second reception window, where the first reception window is obtained based on a distance threshold corresponding to the primary OLT, and the distance threshold is greater than or equal to the maximum value among the distances between the primary OLT and each ONU. The transceiver unit is configured to receive the service data sent by each ONU from the second service channel within the second reception window.

61. The device according to any one of claims 55 - 57, characterized in that, The processing unit is further configured to obtain a compensation delay based on the distance parameter between the device and the first ONU and the distance parameter between the primary OLT and the first ONU. The processing unit is further configured to adjust a first reception window based on the compensated time delay to obtain a second reception window, where the first reception window is obtained based on a distance threshold corresponding to the active OLT, and the distance threshold is greater than or equal to the maximum value among the distances between the active OLT and each ONU; The transceiver unit is configured to receive service data sent by each ONU from the second service channel within the second reception window. The device according to claim 54, characterized in that, The transceiver unit is further configured to send an OLT handover indication to each ONU among the at least one ONU through the second service channel, where the OLT handover indication is used to instruct each ONU to transmit service data with the device through the second service channel.

63. The device according to any one of claims 55-58 and 60, characterized in that, The transceiver unit is further configured to send an OLT handover indication to each ONU among the at least one ONU through the second service channel, where the OLT handover indication is used to instruct each ONU to transmit service data with the device through the second service channel.

64. The device according to claim 59, characterized in that, The transceiver unit is further configured to send an OLT handover indication to each ONU among the at least one ONU through the second service channel, where the OLT handover indication is used to instruct each ONU to transmit service data with the device through the second service channel.

65. The device according to claim 61, characterized in that, The transceiver unit is further configured to send an OLT handover indication to each ONU among the at least one ONU through the second service channel, where the OLT handover indication is used to instruct each ONU to transmit service data with the device through the second service channel.

66. The device according to claim 54, characterized in that, The processing unit is further configured to: Detect an upstream optical signal received through the second service channel; When the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first service channel.

67. The device according to any one of claims 55-58, 60, 62, 64, 65, characterized in that, The processing unit is further configured to: Detect an upstream optical signal received through the second service channel; When the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first service channel.

68. The apparatus according to claim 59, wherein The processing unit is further configured to: Detect an upstream optical signal received through the second service channel; When the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first service channel.

69. The device according to claim 61, characterized in that, The processing unit is further configured to: Detect an upstream optical signal received through the second service channel; When the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first service channel.

70. The device according to claim 63, characterized in that, The processing unit is further configured to: Detect an upstream optical signal received through the second service channel; When the intensity of the detected upstream optical signal is lower than a first threshold, determine that the active OLT stops sending a downstream optical signal on the first service channel.

71. The device according to any one of claims 44-46, 49-52, characterized in that, The distance parameter of the communication between the device and the first ONU includes the equalization delay of the communication between the device and the first ONU, and the transceiver unit is further configured to send the equalization delay to the first ONU.

72. The apparatus according to claim 47, wherein, The distance parameter of the communication between the device and the first ONU includes the equalization delay of the communication between the device and the first ONU, and the transceiver unit is further configured to send the equalization delay to the first ONU.

73. The device according to claim 48, characterized in that, The distance parameter of the communication between the device and the first ONU includes the equalization delay of the communication between the device and the first ONU, and the transceiver unit is further configured to send the equalization delay to the first ONU.

74. The device according to claim 53, characterized in that, The distance parameter of the communication between the device and the first ONU includes the equalization delay of the communication between the device and the first ONU, and the transceiver unit is further configured to send the equalization delay to the first ONU.

75. The device according to any one of claims 44-46, 49-52, 55-58, 60, 62, 64-66, 68-70, 72-74, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

76. The device according to claim 47, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

77. The device according to claim 48, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

78. The device according to claim 53, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

79. The apparatus according to claim 54, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

80. The device according to claim 59, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

81. The device according to claim 61, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

82. The apparatus according to claim 63, wherein The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

83. The device according to claim 67, wherein, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

84. The device according to claim 71, characterized in that, The processing unit is further configured to connect the communication connection between the device and the first optical distribution network (ODN). There is a communication connection between the primary OLT and the first ODN, and the first ODN communicates with the at least one ONU.

85. The device according to claim 75, characterized in that, There is a communication connection between the device and the first interface of the optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and the second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and the at least one ONU included in the second PON system. The processing unit is configured to control the optical router to connect the first interface and the second interface.

86. The device according to any one of claims 76 - 84, characterized in that, There is a communication connection between the device and the first interface of the optical router. The optical router further includes a second interface and at least one third interface. There is a communication connection between the second interface and the first ODN. The at least one third interface corresponds to at least one second PON system one by one. For any one of the at least one third interfaces, there is a communication connection between the third interface and the second ODN included in the second PON system corresponding to the third interface. The second ODN also communicates with the primary OLT and the at least one ONU included in the second PON system. The processing unit is configured to control the optical router to connect the first interface and the second interface.

87. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a computer, it implements the method according to any one of claims 1-43.

88. A computer program product, characterized in that, The computer program product includes a computer program stored in a computer-readable storage medium, and the computer program is loaded by a processor to implement the method according to any one of claims 1-43.

89. A PON system, characterized in that, The PON system includes a primary optical line terminal (OLT), a standby OLT, and at least one optical network unit (ONU). The primary OLT performs window ranging on the at least one ONU through a first management channel, and business data is transmitted between the primary OLT and any ONU through a first service channel. The primary OLT is configured to send a ranging notification to the standby OLT when stopping sending a downstream management signal on the first management channel. The ranging notification is used to instruct the standby OLT to perform ranging. The standby OLT is configured to implement the method according to any one of claims 1-43.

90. The system according to claim 89, wherein The primary OLT is further configured to transmit business data with the at least one ONU through the first service channel when stopping sending a downstream management signal on the first management channel.

91. The system according to claim 89 or 90, wherein The primary OLT is used to periodically send the ranging notification to the standby OLT, or send the ranging notification to the standby OLT when a new ONU goes online and is detected.

Images