Optical line terminal channel terminal protection method, system and device, and storage medium

Abstract

The invention relates to an optical line terminal channel terminal protection method, system and device, and a storage medium, and relates to the technical field of communication. The method is applied to a wavelength division multiplexing passive optical network system, when an adjustable protection optical line terminal channel terminal is in an initial state or a protection state, if an inter-channel terminal protocol activation message sent by any optical line terminal channel terminal is received, the adjustable protection optical line terminal channel terminal enters a pre-working state; in the pre-working state, according to the wavelength channel corresponding to the optical line terminal channel terminal, the working wavelength of the transceiver is tuned; and turning on the transmitter and transmitting a downlink signal, confirming that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishing connection. According to the method, the one-to-many channel terminal protection switching mechanism is realized based on the ICTP activation message through the adjustable protection optical line terminal channel terminal, and the problem that the original protection method cannot realize the one-to-many protection of the OLT CT is solved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an optical line terminal channel terminal protection method, system, communication device and computer-readable storage medium. Background Art

[0002] The high-speed passive optical network (PON) technology that has been widely deployed in the existing network mainly adopts the time-division multiplexing EPON (Ethernet Passive Optical Network) or GPON (Gigabit Passive Optical Network) system, which works on a single wavelength for both upstream and downstream transmissions and is transmitted by allocating their own transmission time. WDM-PON (wavelength division multiplexing passive optical network) uses wavelength division multiplexing technology. The PON port of the central office OLT (Optical Line Terminal) device and the user-side terminal ONU (Optical Network Unit) device each occupy a pair of wavelength channels point-to-point. The number of users that can be connected is several times that of traditional time-division PON. It mainly provides network connections for government and enterprise customers, wireless bearers, etc. Especially in the field of 5G fronthaul, the use of WDM-PON can save backbone optical fiber resources and reduce the cost and difficulty of network installation, maintenance and operation.

[0003] In WDM-PON, the optical distribution network (ODN) adopts a point-to-multipoint network structure, which is composed of single-mode optical fiber, wavelength routing equipment and other passive devices to realize the wavelength-based point-to-point transmission function between the trunk and branch optical fibers. The WDM-PON system provides the corresponding fixed working wavelength for the ONU connected to each branch optical fiber end through the wavelength routing equipment in the ODN. The wavelength is determined by the physical connection and is fixedly allocated based on the wavelength allocation specification of the upstream / downstream transmission of WDM-PON.

[0004] The currently standardized PON system OLT (optical line terminal) CT (channel terminal) Class B protection method is mainly to use the backup OLT to perform one-to-one OLT CT protection on the working OLT. Class B protection refers to a protection method that does not require ONUs and the OLT completes status detection and protection switching. Its main protection means is that the OLT CT and its Class B protection counterpart OLT CT monitor the uplink signal reception status of the wavelength channel in which they are located, and switch the working role (that is, switch between the active role and the backup role) through ICTP (Inter-channel Termination protocol) message interaction, thereby performing protection switching of the working OLT CT.

[0005] The one-to-one OLT CT protection method will increase the redundancy of the equipment and cause resource waste. In addition, according to the characteristics of WDM-PON, the channels are transmitted based on different wavelength channels and are isolated from each other. The OLT CT cannot directly monitor the uplink signals of all wavelength channel pairs globally. Therefore, the original protection method cannot achieve one-to-many protection of the OLT CT, making the backup OLT lack of mechanism universality. Summary of the invention

[0006] Based on this, it is necessary to provide an optical line terminal channel terminal protection method, system, communication equipment and computer-readable storage medium to address the above technical problems, which can realize a one-to-many channel terminal protection switching mechanism through adjustable protection of optical line terminal channel terminals and based on ICTP (Inter-Channel Terminal Protocol) activation messages.

[0007] In a first aspect, the present application provides an optical line terminal channel terminal protection method, the method is applied to a wavelength division multiplexing passive optical network system, the system includes an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, the adjustable protection optical line terminal channel terminal is used to protect the working optical line terminal channel terminal in the same system, the method includes:

[0008] When the adjustable protection optical line terminal channel terminal is in the initial state or protection state, if it receives a channel terminal inter-terminal protocol activation message sent by any working optical line terminal channel terminal, it enters the pre-working state;

[0009] In the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal;

[0010] The adjustable protection optical line terminal channel terminal turns on the transmitter and transmits the downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection.

[0011] In one embodiment, the method further comprises:

[0012] When the adjustable protection optical line terminal channel terminal enters the initial state, the timer is started;

[0013] If the timer times out, the adjustable protection optical line terminal channel terminal enters the protection state.

[0014] In one embodiment, after establishing the connection, the method further includes:

[0015] If the adjustable protection optical line terminal channel terminal in the pre-working state receives an uplink transmission confirmation message, it enters the working state;

[0016] In the working state, if the adjustable protection optical line terminal channel terminal receives an upper management event from the element management system, it enters the help state;

[0017] In the help state, the adjustable protection optical line terminal channel terminal sends a channel terminal inter-protocol activation message to the working optical line terminal channel terminal in the initial state to try to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

[0018] In one of the embodiments, after sending a channel terminal inter-terminal protocol activation message to a working optical line terminal channel terminal in an initial state, the method further includes:

[0019] The adjustable protection optical line terminal channel terminal responds to the fault description event and returns the protection state.

[0020] In one embodiment, the method further comprises:

[0021] If the working optical line terminal channel terminal in the working signal loss state still does not receive the uplink signal within the set time, it enters the help state and periodically sends a channel terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

[0022] In one of the embodiments, after periodically sending a channel terminal inter-terminal protocol activation message to a channel terminal of an adjustable protection optical line terminal, the method further comprises:

[0023] The working optical line terminal channel terminal enters the normal error state;

[0024] Normally, if a working optical line terminal channel terminal in an error state receives reset information from the element management system, it migrates to an initial state.

[0025] In one embodiment, the method further comprises:

[0026] If the working optical line terminal channel terminal in the initial state receives an inter-channel terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal, it migrates to the pre-working state.

[0027] In a second aspect, the present application further provides a wavelength division multiplexing passive optical network system, the system comprising an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, the adjustable protection optical line terminal channel terminal and the working optical line terminal channel terminal are connected via a channel terminal inter-terminal protocol communication; wherein:

[0028] The adjustable protection optical line terminal channel terminal is used to perform the following steps:

[0029] When the adjustable protection optical line terminal channel terminal is in the initial state or protection state, if it receives a channel terminal inter-terminal protocol activation message sent by any working optical line terminal channel terminal, it enters the pre-working state;

[0030] In the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal;

[0031] The adjustable protection optical line terminal channel terminal turns on the transmitter and transmits a downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection;

[0032] The working optical line terminal channel terminal is used to perform the following steps:

[0033] If the working optical line terminal channel terminal in the working signal loss state still does not receive the uplink signal within the set time, it enters the help state and periodically sends a channel terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

[0034] In a third aspect, the present application further provides a communication device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method described in the first aspect above are implemented.

[0035] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method described in the first aspect above are implemented.

[0036] The above-mentioned optical line terminal channel terminal protection method, system, communication equipment and computer-readable storage medium, the wavelength division multiplexing passive optical network system includes an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, the adjustable protection optical line terminal channel terminal is used to protect the working optical line terminal channel terminal under the same system, when the adjustable protection optical line terminal channel terminal is in the initial state or the protection state, if it receives a channel terminal protocol activation message sent by any working optical line terminal channel terminal, it enters the pre-working state; in the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal; the adjustable protection optical line terminal channel terminal turns on the transmitter and transmits the downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection. Through the above method, a one-to-many channel terminal protection switching mechanism is realized through adjustable protection of optical line terminal channel terminals and based on ICTP activation messages, which solves the problem that the original protection method cannot realize one-to-many protection of OLT CT, improves the versatility of the protection mechanism, reduces the complexity of the overall protection switching mechanism, and effectively reduces the overall cost of the WDM-PON system using protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of a WDM-PON system architecture configuration in one embodiment;

[0039] Figure 2 A schematic diagram of a traditional one-to-one protection architecture in an embodiment;

[0040] Figure 3 An application environment diagram of an optical line terminal channel terminal protection method in an embodiment;

[0041] Figure 4 A schematic diagram of a flow chart of an optical line terminal channel terminal protection method in one embodiment;

[0042] Figure 5 A schematic diagram of a Class B protection state machine of a conventional PON system in an embodiment;

[0043] Figure 6 Schematic diagram of an improved Class B protection state machine in one embodiment;

[0044] Figure 7 A schematic flow chart of an optical line terminal channel terminal protection method in another embodiment;

[0045] Figure 8 FIG. 4 is a diagram showing the internal structure of a communication device in one embodiment. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] It is understandable that, referring to Figure 1 , Figure 1 The figure is a schematic diagram of the WDM-PON system architecture configuration in an embodiment. In the WDM-PON, the optical distribution network (ODN) adopts a point-to-multipoint network structure, which is composed of passive components such as single-mode optical fibers and wavelength routing devices to realize wavelength-based point-to-point transmission functions between trunk and branch optical fibers.

[0048] Reference Figure 2 The currently standardized PON system OLT (optical line terminal) CT (channel terminal) Class B protection method is mainly to use the backup OLT to provide one-to-one OLT CT protection for the working OLT. Among them, Class B protection refers to a protection method that has no requirements for ONUs and is completed by the OLT to detect and switch the status. The Protection Wavelength Router (AN) and Wavelength Router (ODN) are wavelength routing devices in the system. Its main protection means is that the OLT CT and its Class B protection counterpart OLT CT monitor the uplink signal reception status of the wavelength channel in which they are located, and switch the working role (that is, switch between the active role and the backup role) through ICTP (Inter-channel Termination protocol) message interaction, thereby performing protection switching of the working OLT CT.

[0049] The inventor of the present application has found that the one-to-one OLT CT protection method will increase the redundancy of the equipment and cause resource waste. In addition, according to the characteristics of WDM-PON, the channels are transmitted based on different wavelength channels and isolated from each other. The OLT CT cannot directly monitor the uplink signals of all wavelength channel pairs globally. Therefore, the original protection method cannot achieve one-to-many protection of the OLT CT, which makes the backup OLT lack mechanism universality.

[0050] Based on this, the present application provides an optical line terminal channel terminal protection method, system, communication device and computer-readable storage medium, which can realize a one-to-many channel terminal protection switching mechanism based on ICTP activation messages through adjustable protection of optical line terminal channel terminals, thereby solving the problem that the original protection method cannot realize one-to-many protection of OLT CT.

[0051] The optical line terminal channel terminal protection method provided in the embodiment of the present application can be applied to Figure 3 In the application environment shown in FIG. 1 , the WDM-PON system is provided with multiple working OLT CTs, namely OLT CT-1, OLT CT-2, ..., OLT CT-n in the working channel terminal group, and a single wavelength tunable protection OLT CT (Backup tunable CT) is applied, namely Figure 3 The OLT CT-x in the OLT CT. The working OLT CT and the protection OLT CT communicate with each other through the channel terminal protocol interface (ICTP interface). Based on the ICTP message sent by each working OLT CT, the protection OLT CT migrates between different states to protect each working OLT CT. It can be understood that in order to facilitate the understanding of the embodiments provided in the present application, some terms that may appear in the drawings and specific descriptions are introduced below: CG refers to Channel Group; CP refers to Channel Pair; CT refers to Channel Termination; WR refers to Wavelength Router; AN refers to access node; ODN refers to optical distribution network; Splitter refers to splitter; Backup tunable CT refers to backup adjustable CT.

[0052] In an exemplary embodiment, Figure 4 As shown, a method for protecting an optical line terminal channel terminal is provided, and the method is applied to a wavelength division multiplexing passive optical network system, the system includes an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, the adjustable protection optical line terminal channel terminal is used to protect the working optical line terminal channel terminal in the same system, and the method includes:

[0053] Step 402: When the adjustable protection optical line terminal channel terminal is in the initial state or the protection state, if a channel terminal protocol activation message sent by any working optical line terminal channel terminal is received, the adjustable protection optical line terminal channel terminal enters the pre-working state.

[0054] Among them, the adjustable protection optical line terminal channel terminal is an OLT CT with adjustable wavelength, and its states include initial state, protection state, pre-working state, working state, and help state. The adjustable protection optical line terminal channel terminal communicates with the working optical line terminal channel terminal through the Inter-Channel Terminal Protocol (ICTP). The Inter-Channel Terminal Protocol activation message (hereinafter referred to as the activation message) is used to instruct the adjustable protection optical line terminal channel terminal to perform state migration and take over the control of the corresponding wavelength channel as an activation role. The activation message can be expressed as an ICTP:Active() message. The system where the adjustable protection optical line terminal channel terminal is located includes one or more working optical line terminal channel terminals. When the adjustable protection optical line terminal channel terminal is in the initial state or protection state, if the ICTP:Active() message sent by any working optical line terminal channel terminal is received through the ICTP interface, the adjustable protection optical line terminal channel terminal enters the pre-working state.

[0055] Step 404: In the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal.

[0056] It is understandable that the wavelength division multiplexing passive optical network system may include multiple working optical line terminal channel terminals, and after the adjustable protection optical line terminal channel terminal enters the pre-working state, the working optical line terminal channel terminal that sends the activation message is taken as the protected object.

[0057] Among them, the adjustable protection optical line terminal channel terminal in the pre-working state tunes the working wavelength of its own transceiver to match the wavelength channel of the working optical line terminal channel terminal that sends the activation message, so that the working wavelength of the transceiver of the adjustable protection optical line terminal channel terminal is within the wavelength channel range of the working optical line terminal channel terminal, so that the adjustable protection optical line terminal channel terminal takes over the control of the wavelength channel to protect the working optical line terminal channel terminal.

[0058] Step 406, the adjustable protection optical line terminal channel terminal turns on the transmitter and transmits the downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection.

[0059] The adjustable protection optical line terminal channel terminal performs signal transmission and reception based on the tuned working wavelength, and the optical network unit (ONU) corresponding to the working optical line terminal channel terminal attempts to establish a connection. Specifically, the connection is attempted to be established by transmitting a downlink signal. If an uplink transmission confirmation message is received, it indicates that the connection is successfully established, and the adjustable protection optical line terminal channel terminal enters a working state. Optionally, if no transmission confirmation message is received within a period of time, it indicates that the connection establishment fails, and a failure of the optical fiber or optical transceiver may occur at this time.

[0060] In an optional implementation, if the connection establishment fails, the adjustable protection optical line terminal channel terminal will enter a normal error state.

[0061] The above optical line terminal channel terminal protection method is applied to a wavelength division multiplexing passive optical network system, and the adjustable protection optical line terminal channel terminal is used to protect the working optical line terminal channel terminal under the same system. When the adjustable protection optical line terminal channel terminal is in the initial state or protection state, if it receives the channel terminal protocol activation message sent by any working optical line terminal channel terminal, it enters the pre-working state; in the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal; the adjustable protection optical line terminal channel terminal turns on the transmitter and transmits the downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection. In the above manner, a one-to-many channel terminal protection switching mechanism is realized based on the ICTP activation message through the adjustable protection optical line terminal channel terminal, which solves the problem that the original protection method cannot realize the one-to-many protection of OLTCT, improves the versatility of the protection mechanism, reduces the complexity of the overall protection switching mechanism, and effectively reduces the overall cost of the WDM-PON system using protection.

[0062] In an exemplary embodiment, the method further includes: when the adjustable protection optical line terminal channel terminal enters the initial state, starting a timer; if the timer times out, the adjustable protection optical line terminal channel terminal enters the protection state.

[0063] Among them, a timer is set at the adjustable protection optical line terminal channel terminal as an alternative way of state migration. After the adjustable protection optical line terminal channel terminal is powered on, it enters the initial state. In the initial state, the adjustable protection optical line terminal channel terminal does not perform a handshake mechanism and starts the timer. If the timer times out, the adjustable protection optical line terminal channel terminal enters the protection state as a backup role. Different from the traditional state migration method, in this embodiment, only the adjustable protection optical line terminal channel terminal can enter the protection state, and the working optical line terminal channel terminal will not enter the protection state.

[0064] Optionally, the state transition process of the adjustable protection optical line terminal channel terminal is as follows: in the initial state, start the timer, and if an activation message is received, enter the pre-protection state. In the initial state, if the timer times out, enter the protection state.

[0065] Optionally, the state transition process of the adjustable protection optical line terminal channel terminal is as follows: in the initial state, start the timer, if the timer times out, enter the protection state. In the protection state, if an activation message is received, enter the pre-protection state.

[0066] In this embodiment, the adjustable protection optical line terminal channel terminal sets a timer and completes the migration process from the initial state to the protection state based on the timer, providing a basis for activating the adjustable protection optical line terminal channel terminal and ensuring the feasibility of the one-to-many channel terminal protection switching mechanism.

[0067] In an exemplary embodiment, after step 206, the method further includes: if the adjustable protection optical line terminal channel terminal in the pre-working state receives an uplink transmission confirmation message, it enters the working state; in the working state, if the adjustable protection optical line terminal channel terminal receives an upper-layer management event of the element management system, it enters the help state; in the help state, the adjustable protection optical line terminal channel terminal sends a channel terminal protocol activation message to the working optical line terminal channel terminal in the initial state to try to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

[0068] Among them, the adjustable protection optical line terminal channel terminal attempts to establish a connection with the optical network unit corresponding to the working optical line terminal channel terminal by sending a downlink signal. If an uplink transmission confirmation message is received, it indicates that the connection is successfully established, and the adjustable protection optical line terminal channel terminal enters the working state. Through the upper management event (for example, EMS: Forced()) of the element management system (EMS), the adjustable protection optical line terminal channel terminal in the working state can be instructed to give up the activation role and transfer the control of the corresponding wavelength channel to the original working optical line terminal channel terminal, that is, the working optical line terminal channel terminal in the initial state. Specifically, the adjustable protection optical line terminal channel terminal responds to the upper management event and enters the help state. In the help state, it sends a channel terminal inter-protocol activation message (for example, ICTP: Active() message) to the working optical line terminal channel terminal in the initial state. It can be understood that after the fault of the protected object is cleared and re-enters the initial state, this embodiment promptly instructs the adjustable protection optical line terminal channel terminal in the working state to send a channel terminal inter-protocol activation message to the protected object through the upper management event, so that the protected object switches to the working role again.

[0069] The working optical line terminal channel terminal responds to the activation message and continues the subsequent state migration, that is, gradually migrates from the initial state to the pre-working state and the working state. Specifically, in the initial state, if the working optical line terminal channel terminal receives the channel terminal protocol activation message, it enters the pre-working state, transmits the downlink signal, and attempts to establish a connection with the optical network unit; if it receives the uplink transmission confirmation message, it enters the working state. In this way, the normal operation of the working optical line terminal channel terminal is restored, and the switching of the working role is realized.

[0070] Optionally, the upper layer management event may be manually input and generated in the element management system, or may be automatically generated by the element management system after monitoring that the channel terminal of the working optical line terminal has recovered to an initial state. This embodiment does not limit this.

[0071] In this embodiment, after the working optical line terminal channel terminal recovers the initial state, the adjustable protection optical line terminal channel terminal transfers the control right of the wavelength channel back to the working optical line terminal channel terminal, ensuring that the wavelength division multiplexing passive optical network system recovers the normal operation state.

[0072] In an exemplary embodiment, after sending a channel terminal inter-protocol activation message to a working optical line terminal channel terminal in an initial state, the method further includes: the adjustable protection optical line terminal channel terminal responds to the fault description event and returns to a protection state.

[0073] Among them, the fault description event can be generated by the working optical line terminal channel terminal, and can also be generated by the adjustable protection optical line terminal channel terminal, which is used to indicate that there is no fault in the transmission link, or that it is temporarily impossible to determine that the fault is caused by the transmission link. The adjustable protection optical line terminal channel terminal responds to the fault description event and returns to the protection state as a backup role, so that it can be triggered by an activation message sent by any working optical line terminal channel terminal to re-execute the steps of the aforementioned optical line terminal channel terminal protection method.

[0074] In this embodiment, the adjustable protection optical line terminal channel terminal switches back to the protection state, providing a reliable backup option for the wavelength division multiplexing passive optical network system. When a problem occurs in any working optical line terminal channel terminal, the backup role can be quickly enabled, thereby maintaining the stability of the wavelength division multiplexing passive optical network system.

[0075] It is understandable that, referring to Figure 5 , Figure 5 Schematic diagram of a Class B protection state machine of a conventional PON system in an embodiment; a conventional OLT CT Class B protection method can be summarized as the following steps:

[0076] 1. The OLT CT that enters the initial state (O1) first performs an ICTP handshake with its Class B protection peer OLT CT to confirm the effective roles (including active roles and backup roles) in the protection allocation. When an OLT CT (assuming it is CT-A) receives an upstream transmission message, it indicates that another OLT CT is activated on the channel pair. CT-A enters the pre-protection state (O2) and continues the handshake. Once the CT-A is declared as a backup role by a specific ICTP message, it will directly enter the protection state (O3).

[0077] 2. CT-A in the protection state will continue to monitor the upstream signal of this channel pair. If no upstream burst is received within a certain period of time, the CT-A will enter the LOS-P state (O4) and ask the Class B protection peer OLT CT (assuming it is CT-B) for potential protection role switching. If CT-B resumes transmission, the CT-A will return to the protection state; if the CT-A is declared as an activated role by a specific ICTP message, it will enter the pre-working state (O5) and try to establish a connection with the subordinate ONU of the channel pair by sending downstream transmission. Once the upstream transmission confirmation is received, CT-A will enter the working state (O6).

[0078] 3. If the CT-A in the working state does not receive the upstream transmission within a certain period of time and declares the subordinate ONU burst loss, it will enter the LOS-W state (O7, i.e. the working signal loss state) and continue to try the downstream transmission. If it still does not receive the upstream burst response within a certain period of time, the CT-A will enter the help state (O8) and request protection switching from CT-B through ICTP message.

[0079] 4. In addition, when CT-A does not receive an uplink signal in response to its own downlink transmission, or does not receive a confirmed message from CT-B, it will enter the normal error state (O9), at which point a fiber or optical transceiver failure may have occurred; when CT-A detects a failure in a major local device that requires immediate protection switching, it will enter the device error state (O10). The CT-A in the above error state will be reinitialized through network management control after the error is eliminated; and if the CT-A in the normal error state receives an uplink burst after the fault is eliminated, it can directly enter the pre-protection state.

[0080] It should be noted that in the traditional OLT CT Class B protection method, the working OLT CT and the protection OLT CT corresponding to the same wavelength channel are one-to-one protected in the protection process, and each OLT CT performs protection switching between the protection state and the working state by monitoring the upstream transmission. In order to achieve one-to-many protection, it is necessary to apply an OLT CT with adjustable wavelength. However, according to the characteristics of WDM-PON, the channels are transmitted based on different wavelength channels and are isolated from each other. The OLT CT cannot directly perform global monitoring of the upstream signals of all wavelength channel pairs. Therefore, the traditional protection mechanism is not compatible with the OLT CT with adjustable wavelength. Based on this, the embodiment of the present application simplifies and improves the original protection process to achieve the availability of the mechanism of applying the OLT CT with adjustable wavelength.

[0081] In an optional implementation, refer to Figure 6 , Figure 6 Schematic diagram of an improved Class B protection state machine in one embodiment; the optical line terminal channel terminal protection method provided in the embodiment of the present application includes the following steps:

[0082] 1. The working OLT CT operates normally, and the wavelength-tunable protection OLT CT is connected and activated and powered on. After the wavelength-tunable protection OLT CT is powered on, the protection OLT CT will enter the initial state (O1).

[0083] 2. The protection OLT CT in the initial state does not perform a handshake mechanism, starts a first timer (hereinafter referred to as the Tpstart timer), and stays in the initial state for a period of time.

[0084] 3. Within the Tpstart time, the working OLT CT still works normally, and the Tpstart timer times out. If the Tpstart timer times out, the protection OLT CT will enter the protection state (O3) as a backup role. In this state machine, only the protection OLT CT will enter the protection state. It can be understood that the protection OLT CT in the protection state is protecting multiple working OLT CTs and can obtain the service information of the working OLT CT.

[0085] 4. When a QLOS event occurs in a working OLT CT, the working OLT CT enters the LOS-W state (O7, i.e., the working signal loss state) and continues to send downlink signals. After a period of time, if the working OLT CT in the O7 state still does not receive the corresponding uplink signal, it sends a channel terminal protocol activation message, i.e., ICTP:Active(), to the protection OLT CT.

[0086] 5. If the protection OLT CT in the initial state receives the ICTP:Active() message, the protection OLT CT will enter the pre-working state (O5) as an activated role, and immediately tune its transmit and receive wavelengths according to the wavelength channel pair where the OLT CT that sent the ICTP message is located, and attempt to connect with the ONU under the channel pair.

[0087] 6. If the protection OLT CT in the protection state receives the ICTP:Active() message, it will enter the pre-working state (O5), tune its transmit and receive wavelengths according to the wavelength channel pair where the OLT CT that sent the ICTP message is located, and attempt to connect with the ONU under the channel pair.

[0088] 7. After receiving the uplink transmission confirmation, the protection OLT CT performs normal operations in the working state.

[0089] 8. When the fault of the original working OLT CT is cleared and it re-enters the initial state (O1), the upper-layer management event EMS:Forced() of the element management system is used to instruct the protection OLT CT in the working state (O6) to give up the activation role and transfer the control of the wavelength channel pair to the original working OLT CT. At the same time, the protection OLT CT enters the help state (O8) and sends the ICTP:Active() message to the original working OLT CT in the initial state (O1).

[0090] 9. The adjustable protection OLT CT in the help state indicates that the transmission link has no faults through a specific event, or that it is temporarily unable to determine that the fault is caused by the transmission link, and returns to the protection state in the backup role. The original working OLT CT will continue the subsequent state migration until the normal working state is restored.

[0091] It should be noted that, refer to Figure 6 Compared with the traditional OLT CT Class B protection method, the optical line terminal channel terminal protection method provided by the present application has the following characteristics:

[0092] 1. The protection OLT CT in the initial state starts the Tpstart timer. If it receives the ICTP:Active() message within the Tpstart time, it will migrate to the pre-working state and make a pre-working attempt; or, if Tpstart times out, it will migrate to the protection state as a backup role.

[0093] 2. The protection OLT CT in the protection state is in the protection state for multiple working OLT CTs and can obtain the service information of the Active OLT CT. When receiving the ICTP:Active() message, it will migrate to the pre-working state, tune its transceiver to the corresponding wavelength channel, and try to connect with the subordinate ONU.

[0094] 3. A wavelength-adjustable protection OLT CT performs channel protection on multiple working OLT CTs through ICTP message interaction, and does not perform state migration through traditional upstream signal monitoring. Therefore, the pre-protection state (O2) and LOS-P state (O4) in the original state machine are not applicable in the system using the wavelength-adjustable protection OLT CT. This embodiment simplifies these states and processes. For example, referring to Table 1, Table 1 shows a state migration method for protecting the OLT CT.

[0095] Table 1:

[0096]

[0097] Reference Figure 6Exemplarily, after the adjustable protection optical line terminal channel terminal enters the help state, the third timer (hereinafter referred to as the Tictp timer) is started. If the Tictp timer times out (i.e., Tictp expires), the adjustable protection optical line terminal channel terminal returns to the protection state. Exemplarily, after the adjustable protection optical line terminal channel terminal enters the initial state, the second timer (hereinafter referred to as the Tsstart timer) is started. If the Tsstart timer times out (i.e., Tsstartexpires), the adjustable protection optical line terminal channel terminal enters the pre-working state. Exemplarily, when the adjustable protection optical line terminal channel terminal is in the working state, if a signal loss event (QLOS event) occurs, the adjustable protection optical line terminal channel terminal enters the LOS-W state (working signal loss state), continues to send downlink signals, and continues to monitor uplink signals. When the adjustable protection optical line terminal channel terminal is in the LOS-W state, the fourth timer (hereinafter referred to as the Thold timer) and the fifth timer (hereinafter referred to as the Twfail timer) are started. If the uplink signal is monitored within the timer time, indicating that the signal loss event is cleared (ie, LOS cleared), the adjustable protection optical line terminal channel terminal returns to the working state; if the Thold timer and the Twfail timer time out (ie, Thold and Twfail expire), the adjustable protection optical line terminal channel terminal enters the help state. Exemplarily, if the adjustable protection optical line terminal channel terminal in the help state receives the ICTP:Standby-Clear() message, it enters the normal error state; if it receives the ICTP:Standby-LOS() message, it enters the protection state. It can be understood that Figure 6 The migration process of the normal error state and the device error state is not shown in the figure. For details, reference may be made to the traditional OLT CT Class B protection method, which is not limited in this embodiment.

[0098] In an exemplary embodiment, Figure 7 As shown, the optical line terminal channel terminal protection method also includes:

[0099] Step 702: If the working optical line terminal channel terminal in the working signal loss state still does not receive an uplink signal within a set time, it enters a help state and periodically sends a channel terminal inter-terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

[0100] Among them, during the normal operation of the wavelength division multiplexing passive optical network system, each working optical line terminal channel terminal is in a working state. If a signal loss event (QLOS event) occurs in any working optical line terminal channel terminal, the working optical line terminal channel terminal enters the LOS-W state (working signal loss state), continues to send downlink signals, and continues to monitor the uplink signal of this wavelength channel. If the uplink signal is not received within the set time, the working optical line terminal channel terminal in the LOS-W state sends an activation message to the adjustable protection optical line terminal channel terminal through the ICTP interface. The set time can be set according to the actual situation, and this embodiment does not limit the specific value.

[0101] In an optional implementation, if the working optical line terminal channel terminal in the LOS-W state does not receive an uplink signal within a set time period, the working optical line terminal channel terminal enters a help state. In the help state, the working optical line terminal channel terminal sends a channel terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

[0102] After receiving the activation message, the adjustable protection optical line terminal channel terminal determines whether it is in the initial state or the protection state; if so, it performs subsequent state migration, and the specific description can be referred to the explanation of the aforementioned steps 402 to 404, which will not be repeated here. If the adjustable protection optical line terminal channel terminal has taken over the working role of other working optical line terminal channel terminals, the working optical line terminal channel terminal in the help state cannot receive the response information at this time, and will continue to maintain the help state and continue to send activation messages periodically at a certain frequency until receiving the response information of the adjustable protection optical line terminal channel terminal.

[0103] In this embodiment, a one-to-many channel terminal protection switching mechanism is implemented through an adjustable protection optical line terminal channel terminal with adjustable wavelength and based on an ICTP activation message, thereby solving the problem that the original protection method cannot achieve one-to-many protection of OLT CT, improving the versatility of the protection mechanism, reducing the complexity of the overall protection switching mechanism, and effectively reducing the overall cost of the WDM-PON system using protection.

[0104] In an exemplary embodiment, after periodically sending a channel terminal protocol activation message to the adjustable protection optical line terminal channel terminal, the method further includes: the working optical line terminal channel terminal enters a normal error state; if the working optical line terminal channel terminal in the normal error state receives reset information from the element management system, it migrates to the initial state.

[0105] Wherein, after the working optical line terminal channel terminal transfers the control right of the wavelength channel to the adjustable protection optical line terminal channel terminal, it enters the normal error state, indicating that a failure of the optical fiber or the optical transceiver may have occurred. Optionally, if the response information sent by the adjustable protection optical line terminal channel terminal is received, the working optical line terminal channel terminal enters the normal error state.

[0106] The reset information is used to indicate that the fault of the working optical line terminal channel terminal has been cleared, and in response to the reset information, the working optical line terminal channel terminal migrates from a normal error state to an initial state. Specifically, after the fault of the working optical line terminal channel terminal is eliminated, the state of the working optical line terminal channel terminal is reinitialized through the element management system, and the working optical line terminal channel terminal receives the reset information sent by the element management system, and based on the reset information, migrates from a normal error state to an initial state.

[0107] In this embodiment, a recovery method of the working optical line terminal channel terminal is provided. After the fault is cleared, the working optical line terminal channel terminal recovers to an initial state, so as to facilitate the subsequent taking over of the control of the wavelength channel from the adjustable protection optical line terminal channel terminal.

[0108] In an exemplary embodiment, the method further includes: if the working optical line terminal channel terminal in the initial state receives an inter-channel terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal, migrating to the pre-working state.

[0109] Among them, when the adjustable protection optical line terminal channel terminal is in the working state, if it receives an upper-layer management event of the element management system, it enters the help state; in the help state, it sends a channel terminal protocol activation message to the working optical line terminal channel terminal in the initial state. The working optical line terminal channel terminal responds to the activation message and continues the subsequent state migration, that is, gradually migrates from the initial state to the pre-working state and the working state. Specifically, when the working optical line terminal channel terminal is in the initial state, if it receives an activation message, it enters the pre-working state, sends a downlink signal, and tries to establish a connection with the optical network unit; if it receives an uplink transmission confirmation message, it enters the working state. In this way, the normal operation of the working optical line terminal channel terminal is restored, and the switching of the working role is realized.

[0110] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0111] Based on the same inventive concept, the embodiment of the present application also provides a wavelength division multiplexing passive optical network system for implementing the optical line terminal channel terminal protection method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more wavelength division multiplexing passive optical network system embodiments provided below can refer to the limitations of the optical line terminal channel terminal protection method above, and will not be repeated here.

[0112] In an exemplary embodiment, referring to the aforementioned Figure 1 The present application provides a wavelength division multiplexing passive optical network system, the system includes an adjustable protection optical line terminal channel terminal and a plurality of working optical line terminal channel terminals, the adjustable protection optical line terminal channel terminal and the working optical line terminal channel terminal are connected through a channel terminal protocol communication; wherein:

[0113] The adjustable protection optical line terminal channel terminal is used to perform the following steps:

[0114] When in the initial state or protection state, if a channel terminal protocol activation message sent by any working optical line terminal channel terminal is received, the pre-working state is entered;

[0115] In the pre-working state, tuning the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal;

[0116] Turn on the transmitter and transmit a downlink signal, confirm that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establish a connection;

[0117] The working optical line terminal channel terminal is used to perform the following steps:

[0118] In the working signal loss state, if the uplink signal is still not received within the set time, the help state is entered, and a channel terminal inter-terminal protocol activation message is periodically sent to the adjustable protection optical line terminal channel terminal.

[0119] In an exemplary embodiment, the adjustable protection optical line terminal channel terminal is further used to: start a timer when entering the initial state; and enter the protection state if the timer times out.

[0120] In an exemplary embodiment, the adjustable protection optical line terminal channel terminal is also used to: in the pre-working state, if an uplink transmission confirmation message is received, enter the working state; in the working state, if an upper-layer management event of the element management system is received, enter the help state; in the help state, send a channel terminal protocol activation message to the working optical line terminal channel terminal in the initial state to try to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

[0121] In an exemplary embodiment, the adjustable protection optical line terminal channel terminal is further used to: respond to a fault description event and return to a protection state.

[0122] In an exemplary embodiment, the working optical line terminal channel terminal is also used to enter an error state; in a normal error state, if reset information from an element management system is received, it migrates to an initial state.

[0123] In an exemplary embodiment, the working optical line terminal channel terminal is further configured to migrate to a pre-working state in an initial state if a channel terminal inter-terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal is received.

[0124] In an exemplary embodiment, a communication device is provided. The communication device may be a server, and its internal structure diagram may be as shown in FIG. Figure 8 As shown. The communication device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the communication device is used to provide computing and control capabilities. The memory of the communication device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the communication device is used to exchange information between the processor and an external device. The communication interface of the communication device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for protecting an optical line terminal channel terminal is implemented.

[0125] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the communication device to which the scheme of the present application is applied. The specific communication device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0126] In an exemplary embodiment, a communication device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the following steps when executing the computer program: when in an initial state or a protection state, if a channel terminal protocol activation message sent by any working optical line terminal channel terminal is received, the pre-working state is entered; in the pre-working state, the working wavelength of its transceiver is tuned according to the wavelength channel corresponding to the working optical line terminal channel terminal; the transmitter is turned on and a downlink signal is transmitted, confirming that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal and establishes a connection.

[0127] In one embodiment, when the processor executes the computer program, the following steps are further implemented: when entering the initial state, starting the timer; if the timer times out, entering the protection state.

[0128] In one embodiment, the processor further implements the following steps when executing the computer program: in the pre-working state, if an uplink transmission confirmation message is received, the processor enters the working state; in the working state, if an upper-layer management event of the element management system is received, the processor enters the help state; in the help state, the processor sends a channel terminal protocol activation message to the working optical line terminal channel terminal in the initial state to attempt to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

[0129] In one embodiment, when the processor executes the computer program, the processor further implements the following steps: responding to the fault description event, returning to the protection state.

[0130] In one embodiment, when the processor executes the computer program, the following steps are also implemented: in the working signal loss state, if the uplink signal is still not received within the set time, it enters the help state and periodically sends a channel terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

[0131] In one embodiment, when the processor executes the computer program, the processor further implements the following steps: entering an error state; in a normal error state, if reset information of the element management system is received, migrating to an initial state.

[0132] In one embodiment, when the processor executes the computer program, the processor further implements the following steps: in the initial state, if a channel terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal is received, the processor migrates to the pre-working state.

[0133] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented: when in an initial state or a protection state, if a channel terminal protocol activation message sent by any working optical line terminal channel terminal is received, a pre-working state is entered; in the pre-working state, according to the wavelength channel corresponding to the working optical line terminal channel terminal, the working wavelength of its transceiver is tuned; the transmitter is turned on and a downlink signal is transmitted, and it is confirmed that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal and establishes a connection.

[0134] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: when entering the initial state, starting the timer; if the timer times out, entering the protection state.

[0135] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: in the pre-working state, if an uplink transmission confirmation message is received, the working state is entered; in the working state, if an upper-layer management event of the element management system is received, the help state is entered; in the help state, a channel terminal protocol activation message is sent to the working optical line terminal channel terminal in the initial state to try to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

[0136] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: in response to the fault description event, returning to the protection state.

[0137] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: in the working signal loss state, if the uplink signal is still not received within the set time length, the help state is entered, and the channel terminal protocol activation message is periodically sent to the adjustable protection optical line terminal channel terminal; after receiving the channel terminal protocol activation message, the adjustable protection optical line terminal channel terminal will enter the pre-working state, and tune the working wavelength of its transceiver to the wavelength channel corresponding to the working optical line terminal channel terminal, turn on the transmitter and transmit the downlink signal, confirm that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establish a connection.

[0138] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: entering an error state; in a normal error state, if reset information of the element management system is received, migrating to an initial state.

[0139] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: in the initial state, if a channel terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal is received, then the computer program is migrated to the pre-working state.

[0140] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0141] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0142] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0143] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for protecting an optical line terminal channel terminal, characterized in that: The method is applied to a wavelength division multiplexing passive optical network system, the system includes an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, the adjustable protection optical line terminal channel terminal is used to protect the working optical line terminal channel terminal in the same system, and the method includes: When the adjustable protection optical line terminal channel terminal is in the initial state or protection state, if it receives a channel terminal inter-terminal protocol activation message sent by any working optical line terminal channel terminal, it enters the pre-working state; In the pre-working state, the adjustable protection optical line terminal channel terminal tunes the working wavelength of its transceiver according to the wavelength channel corresponding to the working optical line terminal channel terminal; The adjustable protection optical line terminal channel terminal turns on the transmitter and transmits a downlink signal, confirms that the optical network unit corresponding to the working optical line terminal channel terminal receives the downlink signal, and establishes a connection.

2. The method according to claim 1, characterized in that The method further comprises: When the adjustable protection optical line terminal channel terminal enters the initial state, the timer is started; If the timer times out, the adjustable protection optical line terminal channel terminal enters a protection state.

3. The method according to claim 1, characterized in that After establishing the connection, the method further includes: If the adjustable protection optical line terminal channel terminal in the pre-working state receives an uplink transmission confirmation message, it enters the working state; In the working state, if the adjustable protection optical line terminal channel terminal receives an upper management event of the element management system, it enters a help state; In the help state, the adjustable protection optical line terminal channel terminal sends a channel terminal protocol activation message to the working optical line terminal channel terminal in the initial state to try to instruct the working optical line terminal channel terminal to migrate from the initial state to the pre-working state.

4. The method according to claim 3, characterized in that After sending the channel terminal inter-terminal protocol activation message to the working optical line terminal channel terminal in the initial state, the method further includes: The adjustable protection optical line terminal channel terminal responds to the fault description event and returns the protection state.

5. The method according to claim 1, characterized in that The method further comprises: If the working optical line terminal channel terminal in the working signal loss state still does not receive the uplink signal within the set time, it enters the help state and periodically sends a channel terminal inter-terminal protocol activation message to the adjustable protection optical line terminal channel terminal.

6. The method according to claim 5, characterized in that After the periodic sending of the channel terminal inter-terminal protocol activation message to the adjustable protection optical line terminal channel terminal, the method further comprises: The channel terminal of the working optical line terminal enters the normal error state; Normally, if a working optical line terminal channel terminal in an error state receives reset information from the element management system, it migrates to an initial state.

7. The method according to claim 6, characterized in that The method further comprises: If the working optical line terminal channel terminal in the initial state receives an inter-channel terminal protocol activation message sent by the adjustable protection optical line terminal channel terminal, it migrates to the pre-working state.

8. A wavelength division multiplexing passive optical network system, characterized in that: The system comprises an adjustable protection optical line terminal channel terminal and a working optical line terminal channel terminal, wherein the adjustable protection optical line terminal channel terminal is connected to the working optical line terminal channel terminal via a channel terminal protocol communication; wherein: The adjustable protection optical line terminal channel terminal is used to perform the steps of the method according to any one of claims 1 to 4; The working optical line terminal channel terminal is used to perform the steps of the method according to any one of claims 5 to 7.

9. A communication device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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