Method for maintaining confidentiality of data after a fault in a submarine cable system and submarine cable system

Abstract

To provide a method for maintaining confidentiality of data after a failure in a submarine cable system and a submarine cable system.SOLUTION: A method includes a step of determining a first disaster tolerance set in response to occurrence of a failure in a first branch, and a step of replacing a target optical signal in a first optical signal with a virtual optical signal. The first branch is any branch in a submarine cable system, the first disaster tolerance set includes at least one wavelength to be used in order for a first terminal station to transmit an optical signal to the first branch. The first optical signal is an optical signal output by the first terminal station, the target optical signal includes optical signals corresponding to each wavelength in the first disaster tolerance set, and the virtual optical signal is an optical signal that does not carry any data content. The method improves transmission stability after disaster tolerance of the submarine cable system and reduces a risk of data leakage.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present application relates to the field of data confidentiality technology, and in particular to a data confidentiality method and a submarine cable system after a failure in the submarine cable system. [Background technology]

[0002] Undersea Fiber Communication Systems are important communication systems that connect various countries and marine equipment with undersea optical fibers. They are abbreviated as undersea cable systems and can span distances of thousands to tens of thousands of kilometers. A Branching Unit (BU) is an underwater device in a submarine cable system, and its main function is to realize the optical fiber interconnection between three ports in the BU through an internal optical fiber connection arrangement. The BU is an important device that constitutes a complex undersea cable system, and the BU can realize business transmission between multiple stations in the submarine cable system.

[0003] As shown in Fig. 1, the BU inserts and drops a bandwidth portion of the trunk between stations A and B into a branch to connect station C, thereby realizing communication between stations A, B, and C. If a fault occurs in the trunk (e.g., station A side), the BU's bandwidth scheduling function establishes an optical fiber pair mode between the non-faulty stations (stations B and C), thereby compensating for the signal power lost on the faulty side to avoid deterioration of transmission performance due to power contention, and ensures that normal communication can still be maintained between the non-faulty stations (stations B and C) during the fault and maintenance period of the submarine cable. Similarly, if a fault occurs in the branch (station C side), the BU's optical path switching function establishes an optical fiber pair mode between the non-faulty stations (stations A and B), thereby ensuring normal communication between the non-faulty stations.

[0004] When a fault occurs in the undersea cable system and a BU performs disaster tolerance, there is a problem of transmitting the work of the faulty station to other stations, so the PRBS (Pseudo Random Bit Sequence) function is applied between stations to ensure data confidentiality. The PRBS function scrambles the information in the data light so that the receiving equipment cannot recognize the content, and further achieves the effect of data confidentiality. In order to realize the PRBS function, it is necessary to use underwater equipment and transmission equipment from the same manufacturer, so that the underwater disaster tolerance operation can trigger the PRBS function of the transmission equipment.

[0005] However, with the popularity of open undersea cable system platforms, it has become common to build undersea cable systems using equipment from different manufacturers. The PRBS function cannot be realized between equipment from different manufacturers, and after the undersea equipment is disaster tolerant, the data from the faulty station cannot be scrambled, which increases the risk of data leakage. Summary of the Invention [Problem to be solved by the invention]

[0006] The present application provides a data confidentiality method and a submarine cable system after a submarine cable system failure, which solves the problem of increasing risk of data leakage after disaster tolerance of underwater equipment in an open submarine cable system. [Means for solving the problem]

[0007] According to a first aspect of an embodiment of the present invention, there is provided a method for maintaining data confidentiality after a fault in a submarine cable system, the method being applied to a submarine cable system, the submarine cable system including a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable, wherein each optical branching device is connected to one branch, and each branch includes a branch submarine cable connected to the optical branching device, and a branch station connected to the branch submarine cable.

[0008] The method includes the steps of determining a first disaster tolerance set in response to a failure occurring in a first branch, the first branch being any branch in a submarine cable system, the first disaster tolerance set including at least one wavelength used by a first terminal station to transmit an optical signal to the first branch station, the first branch station being a branch station in the first branch, and replacing a target optical signal in the first optical signal with a virtual optical signal, the first optical signal being an optical signal output by the first terminal station, the target optical signal including an optical signal corresponding to each wavelength in the first disaster tolerance set, the virtual optical signal being an optical signal not carrying data content, and the wavelength of the virtual optical signal being the same as the wavelength of the target optical signal.

[0009] In the method provided in the embodiment of the present application, after a fault occurs in a submarine cable system, a first disaster tolerance group is determined based on the information of the optical signals transmitted and received during normal operation of a branch station in the first branch that is faulty, and then in the first optical signal sent by the first terminal station, the target optical signal corresponding to the first disaster tolerance group is replaced with a virtual optical signal that does not carry data content. When a fault occurs in a branch of the submarine cable system, the optical signal of the faulty branch is replaced, thereby reducing the risk of data leakage.

[0010] In one possible embodiment, the step of replacing the target optical signal in the first optical signal with the virtual optical signal includes the steps of filtering out the target optical signal in the first optical signal to obtain a first filtered optical signal, generating a virtual optical signal, and multiplexing the first filtered optical signal with the virtual optical signal for output. In this way, when replacing the target optical signal, the target optical signal in the first optical signal can be filtered out, and the generated virtual optical signal is simultaneously multiplexed with the first filtered optical signal obtained by filtering for output, thereby achieving the purpose of replacing the target optical signal.

[0011] In one possible embodiment, after the step of generating the virtual optical signal, the method further includes the steps of determining a power of the target optical signal and a power of the virtual optical signal, and if the power of the virtual optical signal is different from the power of the target optical signal, adjusting the power of the virtual optical signal so that the power of the virtual optical signal is the same as the power of the target optical signal. Filtering only the target optical signal reduces the power of the optical signal transmitted in the submarine cable system, and the reduction in power reduces the transmission quality of the submarine cable system, and by adjusting the power of the virtual optical signal to match the power of the target optical signal, the effect after filtering the target optical signal can be reduced.

[0012] In one possible embodiment, the step of replacing the target optical signal in the first optical signal with the virtual optical signal further includes the steps of: determining a first optical branching device in response to a fault occurring in the first branch, the first optical branching device being an optical branching device connected to the first branch; and controlling the first optical branching device to perform optical path switching and transmit the optical signals corresponding to each wavelength in the first disaster tolerance set to the second terminal station. In this way, after detecting that a fault occurs in the first branch, the first optical branching device corresponding to the first branch is controlled to perform optical path switching, and information transmission between the first branch and the trunk submarine cable is interrupted, thereby maintaining the transmission stability of the submarine cable system.

[0013] In one possible embodiment, after the step of controlling the first optical branching device to perform optical path switching and transmitting the optical signals corresponding to each wavelength in the first disaster tolerance set to the second terminal station, the step of stopping filtering out the target optical signal in the first optical signal and stopping generating the virtual optical signal according to the occurrence of fault resolution in the first branch, and the step of controlling the first optical branching device to perform optical path switching and transmitting the target optical signal to the first branch station are further included. In this way, after the fault in the first branch is resolved, in order not to affect the operation of the submarine cable system, the first branch can be further connected to the trunk submarine cable, i.e., the optical path of the first optical branching device is switched to the normal operation state of the submarine cable system, and the first branch can receive the optical signal sent by the first terminal station.

[0014] In one possible embodiment, before the step of determining the first disaster tolerance set in response to a failure occurring in the first branch, the method further includes the steps of: determining wavelengths used by the first terminal station to transmit optical signals to each branch station; and respectively determining a disaster tolerance set corresponding to each optical branching device based on the wavelengths used by the first terminal station to transmit optical signals to each branch station, where the disaster tolerance set corresponding to each optical branching device includes at least one wavelength used by the first terminal station to transmit optical signals to the branch station connected to the optical branching device. Before determining the first disaster tolerance set, the disaster tolerance set corresponding to each branch station is determined using the wavelengths of the optical signals received by the branch stations, and when a failure occurs in a branch station, the first disaster tolerance set is quickly determined according to the correspondence between the branch stations and the disaster tolerance sets.

[0015] In one possible embodiment, the occurrence of a fault in the first branch includes at least one of the following: a fault in the branch submarine cable in the first branch, a fault in the first branch station, and a fault in the first optical branching device. A branch in a submarine cable system includes a branch submarine cable and a branch station, and the branch is connected to a trunk by an optical branching device, so that factors affecting branch data transmission and reception include a fault in the branch submarine cable, a fault in the branch station, and a fault in the optical branching device, so that when making a judgment of a fault in a branch, the branch submarine cable, the branch station, and the optical branching device can be detected, and if there is a fault in at least one of the three, the branch will fail.

[0016] According to a second aspect of an embodiment of the present invention, there is provided a submarine cable system, comprising: a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable, wherein each optical branching device is connected to one branch, and each branch comprises a branch submarine cable connected to the optical branching device, and a branch station connected to the branch submarine cable.

[0017] The system further includes a wavelength management device installed on the output side of the first terminal station, the wavelength management device is used for determining a first disaster tolerance set in response to occurrence of a fault in the first branch, the first branch being any branch in the submarine cable system, the first disaster tolerance set including at least one wavelength used by the first terminal station to transmit an optical signal to the first branch station, the first branch station being a branch station in the first branch, and replacing a target optical signal in the first optical signal with a virtual optical signal, the first optical signal being an optical signal output by the first terminal station, the target optical signal including optical signals corresponding to each wavelength in the first disaster tolerance set, the virtual optical signal being an optical signal not carrying data content, and the wavelength of the virtual optical signal being the same as the wavelength of the target optical signal. The wavelength management device is used for determining a first disaster tolerance set in response to occurrence of a fault in the first branch, the first branch being any branch in the submarine cable system, the first disaster tolerance set including at least one wavelength used by the first terminal station to transmit an optical signal to the first branch station, the first branch station being a branch station in the first branch, and replacing a target optical signal in the first optical signal with a virtual optical signal, the first optical signal being an optical signal output by the first terminal station, the target optical signal including optical signals corresponding to each wavelength in the first disaster tolerance set, the virtual optical signal being an optical signal not carrying data content, and the wavelength of the virtual optical signal being the same as the wavelength of the target optical signal. In response to a failure in a first branch in a submarine cable system, the optical signal corresponding to the branch station in the first branch is replaced with a virtual optical signal that does not carry data, thereby reducing the problem of data leakage that occurs when disaster tolerance is achieved due to a branch failure in the submarine cable system.

[0018] In one possible embodiment, the wavelength management device includes an optical generation module for generating a virtual optical signal, and a filtering multiplexing module used for filtering out a target optical signal in the first optical signal to obtain a first filtered optical signal, and multiplexing the first filtered optical signal with the virtual optical signal for output. The optical generation module and the filtering multiplexing module are respectively built-in in the wavelength management device, so as to manipulate the first optical signal sent by the first terminal station and replace the target optical signal in the first optical signal.

[0019] In one possible embodiment, the wavelength management device further includes a power detection module for determining the power of the target optical signal and the power of the virtual optical signal, and the filtering and combining module is further used to adjust the power of the virtual optical signal if the power of the virtual optical signal is different from the power of the target optical signal, so that the power of the virtual optical signal is the same as the power of the target optical signal. The power detection module is further installed in the wavelength management device, and the filtering and combining module can more accurately adjust the power of the virtual optical signal, reduce errors during filtering and combining, and reduce the quality impact of the replacement of the target optical signal on subsequent transmission.

[0020] In one possible embodiment, the wavelength management device further determines a first optical branching device according to the occurrence of a fault in the first branch, the first optical branching device being an optical branching device connected to the first branch, and is used for controlling the first optical branching device to perform optical path switching and transmitting optical signals corresponding to each wavelength in the first disaster tolerance set to a second terminal station. After detecting that a fault occurs in the first branch, the wavelength management device controls the optical branching device connected to the first branch to perform optical path switching, blocking the wave up-down signal of the first branch where the fault occurs, and reducing the impact of the faulted first branch on the submarine cable system.

[0021] In one possible embodiment, the wavelength management device is further used for, in response to the fault recovery occurring in the first branch, stopping filtering out the target optical signal in the first optical signal and stopping generating the virtual optical signal, and controlling the first optical branching device to switch the optical path and transmit the target optical signal to the first branch station. After the fault in the first branch is recovered, in order to restore normal operation of the submarine cable system, the wavelength management device further controls the first optical branching device to switch the optical path to a normal operating state, so that the submarine cable system enters a normal operating state after the fault is recovered.

[0022] In one possible embodiment, the wavelength management device further determines the wavelengths used by the first terminal station to transmit optical signals to each branch station, and determines a disaster tolerance set corresponding to each optical branching device according to the wavelengths used by the first terminal station to transmit optical signals to each branch station, respectively, where the disaster tolerance set corresponding to each optical branching device is used to include at least one wavelength used by the first terminal station to transmit optical signals to the branch station connected to the optical branching device. When no fault occurs, the wavelength management device determines the disaster tolerance set of each branch according to the corresponding relationship between each branch station and the received wavelength of the optical signal, so that the first disaster tolerance set can be quickly determined after a fault occurs in a branch.

[0023] In one possible embodiment, the wavelength management device further includes a fault detection module, which is used to detect the working status of the branch cable of the first branch, the first branch station and the first optical branching device. By installing the fault detection module, the wavelength management device can detect the working status of the branch and the corresponding optical branching device, and find the faulty branch in a timely manner. Effect of the Invention

[0024] As can be seen from the above technical solutions, the present application provides a method for maintaining data confidentiality after a fault in a submarine cable system and a submarine cable system, the method including: determining a first disaster tolerance set in response to a fault occurring in a first branch; and replacing a target optical signal in a first optical signal with a virtual optical signal, where the first branch is any branch in the submarine cable system, the first disaster tolerance set includes at least one wavelength used by a first terminal station to transmit an optical signal to the first branch station, the first branch station is a branch station in the first branch, the first optical signal is an optical signal output by the first terminal station, the target optical signal includes optical signals corresponding to each wavelength in the first disaster tolerance set, the virtual optical signal is an optical signal that does not carry data content, and the wavelength of the virtual optical signal is the same as the wavelength of the target optical signal. The method involves determining the wavelength of an optical signal to be transmitted to a first branch when a fault occurs in a branch of a submarine cable system to perform disaster tolerance, and replacing it with a virtual optical signal that does not carry data information. After the submarine cable system has achieved disaster tolerance, the optical signal of the first branch will not be transmitted to other stations, thereby improving the transmission stability of the submarine cable system after disaster tolerance has been achieved and reducing the risk of data leakage. [Brief description of the drawings]

[0025] In order to more clearly explain the technical solutions of the present application, the following briefly introduces the drawings that need to be used in the embodiments, and obviously, those skilled in the art can further derive other drawings based on these drawings without any creative efforts. [Figure 1] FIG. 1 is a structural schematic diagram of a submarine cable system. [Diagram 2] FIG. 2 is a structural schematic diagram of the submarine cable system after a fault. [Diagram 3] 1 is a structural schematic diagram of a submarine cable system in an embodiment of the present application; [Figure 4]2 is a flowchart of a method for maintaining data confidentiality after a failure in a submarine cable system in an embodiment of the present application. [Diagram 5] 4 is a flowchart of a method for maintaining data confidentiality after a failure in another submarine cable system in an embodiment of the present application. [Figure 6] 1 is a flowchart of virtual optical signal generation in an embodiment of the present application. [Figure 7] 1 is a structural schematic diagram of a submarine cable system and a wavelength management device according to an embodiment of the present application; [Figure 8] 1 is a method for maintaining data confidentiality after a fault in a submarine cable system according to an embodiment of the present application; [Figure 9] FIG. 2 is an application scenario diagram of the data confidentiality protection method according to the embodiment of the present application; [Figure 10] FIG. 2 is an application scenario diagram of the data confidentiality protection method according to the embodiment of the present application; [Figure 11] FIG. 2 is an application scenario diagram of the data confidentiality protection method according to the embodiment of the present application; [Figure 12] FIG. 2 is a diagram showing an application scene of a wavelength management device according to an embodiment of the present application. [Figure 13] FIG. 13 is an application scene diagram of another wavelength management device in an embodiment of the present application. [Figure 14] FIG. 13 is an application scene diagram of another wavelength management device in an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in the following description, unless otherwise indicated, the same numerals in the various drawings refer to the same or similar elements. The embodiments described in the following examples do not represent all embodiments consistent with the present application, but are merely examples of devices and methods consistent with certain aspects of the present application, as recited in the claims.

[0027] In the embodiment of the present application, the submarine cable system, that is, the submarine optical fiber communication system, is a communication network system composed of a plurality of submarine communication cables. The communication cables in the system are laid on the seabed, and therefore can be called submarine cable lines. The submarine cable lines can transmit optical signals between terminal stations, and can realize communication functions across ocean areas. The submarine cable system can realize long-distance communication, for example, data communication can be completed across 10,000 kilometers of ocean. Note that the submarine cable system in the embodiment of the present application can also be used in short-distance communication areas, such as across rivers and lakes.

[0028] During the construction of a submarine cable system, if there are several stations between terminal stations, the business transmission capacity in the submarine cable system is small, and the business transmission has confidentiality requirements, the trunk submarine cable between the terminal stations cannot be bypassed to a branch station, so an optical branching unit, i.e., a BU, is installed in the trunk submarine cable to connect the branch submarine cable and the branch station to the trunk submarine cable.

[0029] As shown in Figure 1, stations A and B are terminal stations, station C is a branch station, the three stations are connected by three ports of a BU, and the BU has wave up and down functions, of which the wave down function is to partially transmit the optical signal sent by station A to station C, and the wave up function is to multiplex the optical signal sent by station C with the optical signal sent by station A and output to station B. As can be seen from Figure 1, each BU installed in the trunk submarine cable has a branch submarine cable directly connected thereto in the submarine cable system, so that the BU corresponding to each branch station can be determined by the branch submarine cable connected to the branch station.

[0030] In practical application, take station A as an example to transmit an optical signal. Station A transmits an optical signal within the bandwidth range of the trunk submarine cable. For example, the wavelength of the optical signal transmitted by station A is λ1 to λ2. nAmong them, optical signals with wavelengths λ1 and λ2 are transmitted to station C, and optical signals with wavelengths λ3 to λ n The optical signal from station A is transmitted to station B. When the optical signal from station A passes through the BU, it is connected to a reconfigurable optical add-drop multiplexer (RAD) The optical signals with wavelengths λ1 and λ2 corresponding to station C are separated from the trunk undersea cable by a ROADM (Reverse Add-Drop Multiplexer) and transmitted to station C. At the same time, station C transmits optical signals with wavelengths λ1 and λ2, and transmits the optical signals with wavelengths λ3 to λ4 by the BU. n The optical signal transmitted by station C can be multiplexed with the optical signal from station B and then transmitted via the trunk undersea cable to station B. Although the wavelengths of the optical signals received and transmitted by station C are the same, the optical signal transmitted by station C is modulated so that the data content contained therein is different from that of the optical signal received by station C, and the optical signal transmitted to station C cannot be transmitted to station B, thereby achieving the effect of data confidentiality.

[0031] However, if a fault occurs during transmission, for example in station C or the undersea cable connected to it, station C cannot receive or transmit data, and the optical signals with wavelengths λ1 and λ2 cannot be downlinked to station C. At this time, the optical signal transmitted by station A is directly transmitted to station B via the trunk undersea cable, and the optical signals with wavelengths λ1 and λ2 that should be transmitted to station C are transmitted to station B, causing a risk of data leakage.

[0032] In some embodiments, when a transmission failure occurs in the undersea cable system, the PRBS function can encrypt data that needs to be kept confidential between terminals. For example, as shown in FIG. 2, when a failure occurs in station C or the undersea cable connected to station C, the terminal equipment in station A Therefore, according to the fault information of the BU, the service code in the optical signals with wavelengths of λ1 and λ2 is replaced with a pseudo-random code, so that the optical signal transmitted to station B does not contain the service data corresponding to the optical signals with wavelengths of λ1 and λ2, so that station B cannot obtain the service data transmitted to station C. However, the PRBS function requires the application of terminal equipment and underwater equipment of the same manufacturer during application, so that the underwater equipment can quickly trigger the scrambling function of the terminal equipment after disaster tolerance, thereby realizing data confidentiality.

[0033] However, with the emergence of the concept of open cable, i.e. open submarine cable network, the underwater equipment and the terminal equipment are decoupled, and the underwater equipment and the terminal equipment can be supplied by different manufacturers, so that the renewal and generation change of transmission equipment is not affected by the underwater equipment, reducing the total cost of the submarine cable system and improving the flexibility of the system architecture.In the open cable solution, the manufacturers of the underwater equipment and the surface equipment may be different, so the operation and related warning of the underwater equipment cannot be transmitted to the terminal equipment, and the PRBS function cannot be triggered, which brings the risk of data leakage in the underwater cable system during the disaster tolerance of the equipment.

[0034] The embodiments of the present application provide a method for maintaining data confidentiality after a failure in a submarine cable system, which solves the problem that the submarine cable system has a risk of data leakage during the disaster tolerance of the equipment. In some embodiments of the present application, the data confidentiality method is applied to the submarine cable system, and when a branch failure occurs in the submarine cable system, the transmitted data can be processed to reduce the risk of data leakage in the submarine cable system.

[0035] For example, the submarine cable system may include a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable. Wherein, each optical branching device is connected to one branch, and each branch includes a branch submarine cable connected to the optical branching device and a branch station connected to the branch submarine cable. In some embodiments, before the first terminal station launches an optical signal into the trunk submarine cable, the optical signal needs to be modulated by a modulation device in the first terminal station, so that the optical signals of different wavelengths carry data, thereby meeting the data requirements of different stations. In order to prevent the signal modulation process from affecting the wavelength of the optical signal, the terminal station adopts a coherent modulation method during the optical signal modulation to carry data on the optical signal.

[0036] Taking the first terminal station in the undersea cable system as an example, as shown in FIG. 3, a wavelength management device 700 is further installed between the first terminal station and the optical branching device closest to the first terminal station in the trunk, the wavelength management device 700 can process after a fault occurs in the undersea cable system, and the signal processed by the wavelength management device 700 is the optical signal output by the first terminal station.

[0037] In an embodiment of the present application, the data confidentiality method can be applied to the submarine cable system described above, and as shown in FIG. 4, the data confidentiality method includes:

[0038] In S410, in response to a failure occurring in the first branch, a first disaster tolerance set is determined.

[0039] Wherein, the first branch is any branch submarine cable in a submarine cable system, the first disaster tolerance set includes at least one wavelength used by the first terminal station to transmit an optical signal to the first branch station, and the first branch station is a branch station in the first branch.

[0040] In some embodiments, the wavelength management device 700 determines a disaster tolerance set corresponding to each branch station and optical branching device when no fault occurs in the submarine cable system, so that when a fault occurs in the first branch, the first disaster tolerance set can be determined in a timely manner. Illustratively, before determining the first disaster tolerance set, as shown in FIG. 5, the data confidentiality method further includes:

[0041] In S401, a first terminal station determines the wavelengths to be used for transmitting optical signals to each branch station.

[0042] There are various methods for each branch station to obtain the wavelength at which it receives an optical signal. For example, the correspondence between the wavelength of the optical signal and the branch station is obtained based on configuration information in the transmission equipment of the first terminal station and each branch station, the optical signal transmitted by the first terminal station is separated by wavelength, and the optical signals transmitted to different branch stations are separated. Also, for example, the wavelength management device 700 detects the wavelengths of the optical signals received and transmitted by each branch station during normal operation of the submarine cable system, and thereby obtains the wavelengths used by each branch station to transmit optical signals.

[0043] It should be understood that each branch station is assigned an optical signal of at least one wavelength, so that each branch station is capable of receiving data transmitted from the first terminal station.

[0044] In S402, the first terminal station determines a disaster tolerance set corresponding to each optical branching device based on the wavelengths used to transmit optical signals to each branch station.

[0045] Among them, the disaster tolerance set corresponding to each optical branching device includes at least one wavelength used by the first terminal station to transmit an optical signal to a branch station connected to the optical branching device. After determining the wavelength used by the optical signal transmitted by each branch station, the wavelength of the optical signal corresponding to each optical branching device is determined based on the correspondence between the branch stations and the optical branching devices, so as to obtain the disaster tolerance set corresponding to each optical branching device.

[0046] It should be understood that the contents of the disaster tolerance sets corresponding to each optical branching device may be partially the same or entirely different, and this application does not place any restrictions on the wavelengths of optical signals specifically included in each disaster tolerance set.

[0047] After determining the disaster tolerance set corresponding to each optical branching device, when a fault occurs in the first branch and disaster tolerance is to be performed, first, the optical branching device corresponding to the first branch is determined based on the connection relationship between the branch submarine cable and the trunk submarine cable in the first branch, and then the disaster tolerance set corresponding to that optical branching device is determined as the first disaster tolerance set.

[0048] During operation of the submarine cable system, the wavelength management device 700 can monitor and measure the data transmission status in the submarine cable system and obtain information on faults that may occur in the submarine cable system. Specifically, the wavelength management device 700 can monitor and measure the branch submarine cable of the first branch, the first branch station corresponding to the first branch, and the first optical branching device corresponding to the first branch, among which the first optical branching device is an optical branching device connected to the first branch. When the wavelength management device 700 monitors and measures that a fault has occurred in any of the above-mentioned devices, it determines that a fault has occurred in the first branch, i.e., the fault in the first branch is determined to be at least one of the following: a fault has occurred in the branch submarine cable in the first branch, a fault has occurred in the first branch station, and a fault has occurred in the first optical branching device. For example, the occurrence of a fault in the branch submarine cable in the first branch includes interruption of the branch submarine cable, increase in loss of the branch submarine cable, etc., the occurrence of a fault in the first branch station includes failure of equipment in the first branch station, the first branch station being unable to transmit and receive optical signals, etc., and the occurrence of a fault in the first optical branching device includes the first optical branching device being unable to wave-up and / or wave-down optical signals. The above fault situations are exemplified in the present application, and the present application does not limit the type of fault occurring in the first branch.

[0049] If an abnormality occurs in any of the branch submarine cable, the first branch station, and the first optical branching device corresponding to the first branch, the communication connection relationship between the first branch station and the trunk submarine cable is affected, so that the first optical branching device cannot realize the up-down function of the optical signal. For example, if an interruption occurs in the branch submarine cable of the first branch, the first branch will have a situation in which the first optical branching device cannot down-down the optical signal to the first branch station, and the first branch station cannot up-up the optical signal to the first optical branching device, and if an abnormality occurs in the signal transmission and reception in the first branch station, the first branch will have a situation in which the first optical branching device cannot receive the optical signal of the first branch station and up-up the optical signal. Therefore, in some other embodiments of the present application, the monitoring and measuring of the first branch can be simplified to monitoring and measuring the up-down situation of the first optical branching device by installing a monitoring and measuring device in the first optical branching device, thereby judging the transmission performance of the first branch.

[0050] After monitoring and measuring that a fault has occurred in the first branch, the wavelength management device 700 can determine a first disaster tolerance set based on wavelength information of the transmission signal between the first terminal station and the first branch station.

[0051] It should be understood that the number of wavelengths included in the first disaster tolerance set is related to the wavelength of the optical signal that the first branch station can receive. For example, if the first branch station can receive optical signals with wavelengths λ1 and λ2, the wavelength information included in the first disaster tolerance set is λ1 and λ2, where λ1 and λ2 are not a single definite wavelength value but are used to represent a wavelength range, for example, 1560nm-1561nm. This application does not limit the wavelength information specifically included in the first disaster tolerance set.

[0052] In addition, the content included in the first disaster tolerance set is one feature of the optical signal transmitted from the first terminal station to the first branch station, and is therefore distinguished from other optical signals transmitted to the submarine cable, and in some embodiments of the present application, is represented by the wavelength of the optical signal. Since the propagation speed of an optical signal is the product of the wavelength of the optical signal and the frequency of the optical signal, when the propagation speed of the optical signal is the same, the frequency of the optical signal and the wavelength of the optical signal exhibit a negative correlation, that is, the higher the frequency, the shorter the wavelength, and the lower the frequency, the longer the wavelength. Therefore, in some embodiments of the present application, the first disaster tolerance set can further limit the optical signal by two parameters, the start frequency and the end frequency of the optical signal.

[0053] In some embodiments of the present application, after the assembly of the submarine cable system is completed, the wavelengths of the receiving and transmitting optical signals are assigned at the terminal stations and branch stations in order to clarify the channel that each station occupies during transmission, thereby clarifying the wavelength of the optical signals of each branch station during use of the submarine cable system and improving the efficiency of disaster tolerance.

[0054] In S420, the target optical signal in the first optical signal is replaced with the virtual optical signal.

[0055] Among them, the first optical signal is an optical signal output by the first terminal station, and the target optical signal is The virtual optical signal is an optical signal that does not carry data content, and the wavelength of the virtual optical signal is the same as the wavelength of the target optical signal.

[0056] In the embodiment of the present application, replacing the target optical signal in the first optical signal with the virtual optical signal can be realized by the wavelength management device 700. The wavelength management device 700 is installed between the first terminal station and the optical branching device closest to the first terminal station, so that the first optical signal output from the first terminal station first passes through the wavelength management device 700, and when the wavelength management device 700 detects that a fault has occurred in the submarine cable system and performs disaster tolerance, it determines a first disaster tolerance set and then processes the first optical signal, thereby reducing the risk of data leakage.

[0057] Exemplarily, after determining the first disaster tolerance set, the wavelength management device 700 can obtain a target optical signal corresponding to the first disaster tolerance set in the first optical signal. It should be understood that the information included in the first disaster tolerance set is wavelength information of the optical signal, and therefore the target optical signal is an optical signal whose wavelength is the same as the wavelength information included in the first disaster tolerance set. For example, if the wavelength information in the first disaster tolerance set is λ1 and λ2, the target optical signal is, namely, an optical signal with wavelength λ1 and an optical signal with wavelength λ2. If the first optical signal output by the first terminal station has wavelengths λ1 to λ2, the target optical signal is an optical signal with wavelength λ1 and wavelength λ2. n For example, the first optical signal has a wave number n, the wave number of the target optical signal is the same as the number of wavelength information contained in the first disaster tolerance set, and the wave number of the target optical signal is smaller than the wave number n of the first optical signal.

[0058] It should be noted that the first optical signal and the target optical signal in the embodiment of the present application are both modulated optical signals carrying data content. After the failure occurs in the first branch, in order to reduce the risk of data leakage, the wavelength management device 700 generates a virtual optical signal to replace the target optical signal, and in order to achieve the effect of confidentiality, the virtual optical signal is an unmodulated optical signal. By replacing the modulated target optical signal with the virtual optical signal, the data content carried by the target optical signal is replaced with an optical signal that does not carry data, so that confidentiality leakage caused by the optical signal carrying confidential data being transmitted to other stations in the undersea cable system can be avoided.

[0059] According to the above embodiment, a data confidentiality method is provided, in which after a fault occurs in a submarine cable system, a first disaster tolerance group is determined based on the information of optical signals transmitted and received during normal operation of a branch station in the first branch where the fault occurs, and then in the first optical signal sent by the first terminal station, the target optical signal corresponding to the first disaster tolerance group is replaced with a virtual optical signal that does not carry data content. When a fault occurs in a branch of the submarine cable system, the optical signal of the faulty branch is replaced, thereby reducing the risk of data leakage.

[0060] Furthermore, when a fault occurs in the first branch in the submarine cable system, the first branch station cannot receive or transmit the optical signal, but when the optical branching device does not fail, the optical branching device corresponding to the first branch still down-converts the optical signal, which affects the transmission performance of the non-faulty end. Therefore, in order to maintain the normal data transmission of the non-faulty end, after replacing the target optical signal in the first optical signal with the virtual optical signal, as shown in Figure 5, the data confidentiality method further includes:

[0061] In S431, in response to the occurrence of a failure in the first branch, the first optical branching device is determined.

[0062] Among them, the first optical branching device is an optical branching device connected to the first branch. When a fault occurs in the first branch, the wavelength management device 700 determines the first optical branching device based on the connection relationship between the optical branching device and the first branch. As can be seen from the structure of the submarine cable system, each BU installed in the trunk submarine cable has a branch submarine cable directly connected thereto in the submarine cable system, and the corresponding first optical branching device can be determined according to the connection information of the first branch.

[0063] In some embodiments, the wavelength management device 700 is further used to detect a fault condition in the first branch, and the wavelength management device 700 is installed between the first optical branching device and the first terminal station, so that when a fault occurs in the first branch, the first optical branching device can directly transmit fault information to the wavelength management device 700, and the wavelength management device 700 can respond to the fault in the first branch.

[0064] In S432, the first optical branching device is controlled to switch the optical path, and the optical signals corresponding to the wavelengths in the first disaster tolerance set are transmitted to the second terminal station.

[0065] After determining the first optical branching device corresponding to the first branch, the wavelength management device 700 controls the first optical branching device to perform optical path switching, interrupting information transmission between the trunk submarine cable and the branch submarine cable, and reducing the influence of the faulty end on the non-faulty end. Exemplarily, the wavelength management device 700 can control the optical path switching of the optical branching device by the ROADM built in the optical branching device, and when a transmission fault occurs in the first branch, adjust the optical branching device to an optical fiber pair mode between the first terminal station and the second terminal station, thereby performing optical path switching. Note that realizing the optical path switching by the ROADM built in the optical branching device is merely one possible embodiment of the optical path switching, and the present application does not limit the specific form of the optical path switching.

[0066] It should be understood that the optical signal transmitted to the second terminal station further includes other optical signals than the target optical signal in the first optical signal, and the target optical signal is replaced with a virtual optical signal by the wavelength management device 700; therefore, in the optical signal transmitted to the second terminal station after the optical path switching is performed, the optical signals corresponding to each wavelength in the first disaster tolerance set are all virtual optical signals, and the content in the target optical signal does not exist in the optical signal transmitted to the second terminal station, thereby achieving the effect of data confidentiality.

[0067] After a fault occurs in the submarine cable system, maintenance personnel can perform maintenance on the fault, and after the maintenance is performed to eliminate the fault, normal operation of the submarine cable system can be restored. Therefore, in some embodiments, it means that when the fault in the first branch is eliminated, the first branch can transmit the optical signal, and at this time, the method further includes:

[0068] In S433, in response to the fault clearance occurring in the first branch, stop filtering out the target optical signal in the first optical signal, and stop generating the virtual optical signal.

[0069] In some embodiments, after a fault occurs in the first branch and disaster tolerance is performed, the wavelength management device 700 can send a probe optical signal to the first branch to check whether the fault in the first branch has been removed, where the probe optical signal can be an optical signal of any wavelength. Exemplarily, after a fault occurs in the first branch, the wavelength management device 700 sends a probe optical signal to the first branch in real time to detect the state of the first branch; if the fault in the first branch is removed, the probe optical signal is received by the first branch station, and the first branch station receives the probe optical signal. , generate a corresponding restored optical signal and wave it up to the trunk submarine cable, so that the wavelength management device 700 can consider the fault in the first branch to be resolved once it receives the restored optical signal from the trunk submarine cable.

[0070] In some other embodiments of the present application, after the fault in the first branch is eliminated, the first branch station can transmit an optical signal to the optical branching device, and after receiving the optical signal transmitted by the first branch station, the optical branching device can transmit a signal to the wavelength management device 700, indicating that the fault in the first branch is eliminated and normal data transmission can be performed.

[0071] After detecting that the fault in the first branch has been resolved, the wavelength management device 700 can stop filtering out the target optical signal in the first optical signal and stop generating the virtual optical signal, thereby restoring normal operation of the submarine cable system.

[0072] It should be understood that since the wavelength of the target optical signal is the same as that of the virtual optical signal, they occupy the same channel in the submarine cable, and in this embodiment, the filtering of the target optical signal and the generation of the virtual optical signal should be stopped simultaneously, thereby avoiding contention between optical signals of the same wavelength and making the operation of the submarine cable system more stable.

[0073] In S434, the first optical branching device is controlled to switch the optical path, and the target optical signal is transmitted to the first branch station.

[0074] After the fault in the first branch is eliminated, the wavelength management device 700 can control the optical branching device to perform optical path switching so that the first branch station can receive the target optical signal again. Exemplarily, the wavelength management device 700 controls the first optical branching device to perform optical path switching, thereby transmitting a part of the first optical signal sent from the first terminal station to the first branch station.

[0075] It should be understood that the optical path switching in this step and the optical path switching in step S432 are reverse processes, and the optical path switching in step S432 switches the optical path of the first optical branching device from a three-end interconnection between the first terminal station, the first branch station, and the second terminal station to a two-end interconnection between the first terminal station and the second terminal station, while the optical path switching in this step switches the optical path of the first optical branching device from a two-end interconnection between the first terminal station and the second terminal station to a three-end interconnection between the first terminal station, the first branch station, and the second terminal station.

[0076] According to the above embodiment, a data confidentiality method is provided, and when data confidentiality is performed, the optical branching device corresponding to the first branch performs optical path switching to ensure the normal operation of the non-faulty station in the submarine cable system, and after detecting that the first branch has a fault, the first optical branching device corresponding to the first branch performs optical path switching to interrupt the information transmission between the first branch and the trunk submarine cable, thereby maintaining the transmission stability of the submarine cable system. Furthermore, after the fault in the first branch is eliminated, the first branch can be reconnected to the trunk submarine cable without affecting the operation of the submarine cable system, i.e., the optical path of the first optical branching device is switched to the normal operation state of the submarine cable system, so that the first branch can receive the optical signal transmitted by the first terminal station.

[0077] In some embodiments of the present application, in order to realize data confidentiality and not affect the transmission stability of the submarine cable system, a virtual optical signal can be processed when replacing the optical signal. As shown in Figure 6, replacing the target optical signal in the first optical signal with a virtual optical signal can include the following steps:

[0078] In S610, a target optical signal in the first optical signal is filtered out to obtain a first filtered optical signal.

[0079] First, the wavelength management device 700 needs to filter out the target optical signal in the first optical signal to obtain a first filtered optical signal. Since the target optical signal is an optical signal corresponding to the wavelength information in the first disaster tolerance set, the first filtered optical signal does not include an optical signal corresponding to the wavelength in the first disaster tolerance set. For example, when the wavelength of the first optical signal is λ1 to λ2, the first filtered optical signal does not include the target optical signal corresponding to the wavelength in the first disaster tolerance set. n and the wavelengths of the first disaster tolerance set include λ1 and λ2, the optical signals having wavelengths λ1 and λ2 in the first optical signal are filtered out by a filter or other method, so that the wavelengths λ3 to λ n A first filtered optical signal is obtained.

[0080] In addition, while the first terminal station is emitting the first optical signal, the first terminal station modulates the optical signals of each frequency band, and after the modulation is completed, the optical signals of different frequency bands are multiplexed, so that the optical signals of different frequency bands are transmitted simultaneously in the trunk submarine cable.

[0081] Therefore, in some embodiments, the wavelength management device 700 adjusts the filtering waveband based on the wavelength information in the first disaster tolerance set before filtering the target optical signal in the first optical signal, and filters out the optical signal corresponding to the wavelength in the first disaster tolerance set when the first optical signal passes through the wavelength management device 700, thereby obtaining a first filtered optical signal.

[0082] At S620, a virtual optical signal is generated.

[0083] The virtual optical signal does not need to be modulated, and only needs to generate an optical signal of a corresponding wavelength based on the wavelength information in the first disaster tolerance set. The virtual optical signal is used to supplement the filtered target optical signal, and reduces the power fluctuation of the optical signal transmitted in the trunk submarine cable, thereby reducing the impact of the replacement of the target optical signal on the quality of signal transmission.

[0084] In some embodiments, in order to improve the transmission quality of the submarine cable system and extend the transmission distance of the submarine cable system, optical amplifiers are installed in the trunk submarine cable and the branch submarine cable to obtain gain for the signal transmitted in the submarine cable system. In the optical amplifier, the pump light source amplifies the optical signal passing through the excited particles from high level back to low level, and the excited particles also generate random incoherent spontaneous emission and send out the optical signal. Therefore, the wavelength management device 700 can use the same principle as the optical amplifier to generate a virtual optical signal by spontaneous emission amplification instead of the target optical signal.

[0085] It should be understood that, during amplifying optical signals in optical amplifiers, spontaneous emission amplification belongs to noise and needs to be eliminated to ensure the quality of transmission gain of optical amplifiers, so the spontaneous emission light source that generates virtual optical signals is not an optical amplifier for gaining optical signals.

[0086] For example, a spontaneous emission light source can be installed in the wavelength management device 700, and an optical signal of a wavelength corresponding to the first disaster tolerance set can be generated by spontaneous emission. The optical signal generated by spontaneous emission is not modulated, so it does not carry data content, and can be multiplexed with the first filtered optical signal as a virtual optical signal to stabilize the transmission signal power in the trunk submarine cable.

[0087] In some embodiments of the present application, after generating a virtual optical signal in order to improve the transmission signal power in the trunk submarine cable after the disaster tolerance of the submarine cable system, stabilize the transmission quality of the submarine cable system, reduce the problem of transmission performance degradation caused by power contention, and allow the equipment at the non-fault end to operate normally, as shown in FIG. 6 , the data confidentiality method further includes:

[0088] In S621, the power of the target optical signal and the power of the virtual optical signal are determined.

[0089] The wavelength management device 700 utilizes equipment capable of detecting the power of an optical signal in a submarine cable system, and while the first optical signal and the virtual optical signal are being transmitted to the wavelength management device 700, detects a target optical signal in the first optical signal and a virtual optical signal generated by the wavelength management device 700 itself, thereby obtaining power information corresponding to the target optical signal and the virtual optical signal.

[0090] In some embodiments, the power of the target optical signal can be determined in other ways. For example, the wavelength management device 700 can detect the power of the first optical signal sent from the first terminal, and detect the power of the first filtered optical signal after filtering, and then determine the power of the target optical signal by the difference between the two.

[0091] In some other embodiments, the wavelength management device 700 detects power information of optical signals of different wavelengths in the first optical signal during normal operation of the submarine cable system, and in the above steps S401 and S402, writes the power information of the optical signals of different wavelengths into corresponding disaster tolerance sets based on the wavelength, and after determining the first disaster tolerance set, the power of the target optical signal can be obtained from the first disaster tolerance set.

[0092] In S622, if the power of the virtual optical signal is different from the power of the target optical signal, the power of the virtual optical signal is adjusted so that the power of the virtual optical signal becomes the same as the power of the target optical signal.

[0093] After determining the power of the target optical signal and the power of the virtual optical signal, the wavelength management device 700 compares the two powers, and if the power of the virtual optical signal is different from the power of the target optical signal, it can adjust the power of the virtual optical signal. Exemplarily, if the power of the virtual optical signal is greater than the power of the target optical signal, it attenuates the virtual optical signal, and if the power of the virtual optical signal is less than the power of the target optical signal, it amplifies the virtual optical signal.

[0094] It should be understood that the purpose of attenuating or amplifying the virtual optical signal is to adjust the power of the virtual optical signal to the same level as the power of the target optical signal, and to reduce the change in the optical signal power during the replacement of the target optical signal. During filtering and multiplexing, due to influencing factors such as insertion loss between the equipment and the submarine cable, the power fluctuation value of the optical signal transmitted in the submarine cable system may be greater than the power of the target optical signal or the virtual optical signal, and in this case, only the power of the virtual optical signal is adjusted to the power of the target optical signal, and the power of the optical signal obtained after multiplexing may be different from the power of the first optical signal.

[0095] In some embodiments of the present application, after the first filtered optical signal and the virtual optical signal are multiplexed, the power of the first optical signal is detected, and the power of the optical signal obtained after multiplexing is adjusted to the power magnitude of the first optical signal, so that the power in the undersea cable system can be kept stable, and the problem of transmission performance degradation caused by changes in signal power can be reduced.

[0096] In S630, the first filtered optical signal is multiplexed with the virtual optical signal and output.

[0097] After generating the virtual optical signal, the virtual optical signal is multiplexed with the first filtered optical signal, and then outputted to the trunk submarine cable for transmission, replacing the target optical signal in the first optical signal. The effect can be achieved.

[0098] According to the above embodiment, when replacing the target optical signal, the target optical signal in the first optical signal is first filtered and removed, and the generated virtual optical signal is multiplexed with the first filtered optical signal obtained by filtering the virtual optical signal and output, thereby achieving the purpose of replacing the target optical signal. At the same time, during the replacement of the target optical signal, power control is performed on the virtual optical signal, so as to reduce the deterioration of transmission performance caused by power change and maintain data transmission between non-fault end devices.

[0099] Based on the above-mentioned data confidentiality method for a submarine cable system, the present application further provides a submarine cable system, which includes a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable, and as shown in Figures 7 and 8, the submarine cable system further includes a wavelength management device 700 installed between the output side of the first terminal station and the optical branching device closest to the first terminal station, and the wavelength management device 700 can be used to implement the data confidentiality method provided in each of the above embodiments.

[0100] The wavelength management device 700 is used for determining a first disaster tolerance set and replacing a target optical signal in a first optical signal with a virtual optical signal in response to a fault occurring in a first branch, where the first branch is any branch submarine cable in a submarine cable system, the first disaster tolerance set includes at least one wavelength used by a first terminal station to transmit an optical signal to a first branch station, and the first branch station is a branch station in the first branch.

[0101] The wavelength management device 700 can monitor and measure the transmission status of each branch in the submarine cable system, and thereby determine whether a fault exists in the submarine cable system. Exemplarily, in some embodiments, the wavelength management device 700 includes an optical generation module 710 and a filtering and combining module 720, which replaces the target optical signal in the first optical signal sent by the first terminal station. It should be understood that the optical generation module 710 and the filtering and combining module 720 are connected by optical fiber or other medium capable of transmitting optical signals so that the generated virtual optical signal can be output.

[0102] 9 to 11 are application scenario diagrams of the data confidentiality protection method in the embodiments of the present application. As shown in FIG. 9, for example, during normal operation of the submarine cable system, the first terminal station transmits the data with wavelengths λ1 to λ nThe first optical branching device 700 transmits an optical signal having a wavelength of λ1 and a wavelength of λ2, and a part of the optical signal is down-converted to the first branch station by the first optical branching device, i.e., the BU shown in the figure. After the first branch station receives the optical signals having wavelengths of λ1 and λ2, the first branch station modulates the optical signals having these wavelengths, carries the output data of the first branch station, and then outputs the modulated optical signals. At this time, the wavelength management device 700 detects the status of the first branch in the submarine cable system by the fault detection module 740.

[0103] Specifically, the light generating module 710 may be an amplified spontaneous emission (ASE) light source, which is used to generate a virtual light signal. Among them, the spontaneous emission light source can be similar to the structure of an optical amplifier, in which a pump light source excites particles to a high level, and then the excited particles spontaneously emit, emitting photons, and forming an optical signal after further amplification. The above structure is one possible embodiment of the spontaneous emission light source, and the specific configuration of the spontaneous emission light source is not limited in this application.

[0104] The filtering / combining module 720 filters the target optical signal in the first optical signal. The filtering multiplexing module 720 is used to filter and remove the target optical signal in the first optical signal based on the wavelength, obtain a first filtered optical signal, and multiplex the first filtered optical signal with the virtual optical signal for output. Exemplarily, the filtering multiplexing module 720 can be realized by a Wavelength Selective Switch (WSS). The Wavelength Selective Switch uses free space optical switching technology to support multi-ports, and supports arbitrary upstream and downstream wavelengths of any port. In the embodiment of the present application, the Wavelength Selective Switch can filter and remove the target optical signal in the first optical signal based on the wavelength, and can also multiplex the first filtered optical signal with the virtual optical signal for output.

[0105] In some embodiments, the power of the virtual optical signal can be further limited during the optical signal replacement in order to reduce the power variation of the optical signal in the undersea cable system. To this end, the wavelength management device 700 further includes a power detection module 730, which is used to determine the power of the virtual optical signal and the power of the target optical signal.

[0106] For example, the function of the power detection module 730 can be realized by an optical channel monitoring (OCM) unit, which can detect the power of the first optical signal sent by the first terminal station and the virtual optical signal generated by the optical generating module 710. In order to detect the power of the optical signals, the optical channel detection unit needs to receive the first optical signal and the virtual optical signal, so as to perform power detection and send the power detection result to the filtering multiplexing module 720.

[0107] Taking the filtering multiplexing module 720 as a wavelength selective switch and the power detection module 730 as an optical channel detection unit as an example, the optical channel detection unit may be connected only to the wavelength selective switch by optical fibers, and the wavelength selective switch receives the corresponding optical signal and then transmits it down to the optical channel detection unit for power detection. In some embodiments, the optical channel detection unit may be connected respectively to the first terminal, the optical generating module 710, and the wavelength selective switch by optical fibers, respectively receiving the first optical signal sent by the first terminal and the virtual optical signal generated by the optical generating module 710, detecting the power, and then transmitting the power detection result together with the first optical signal and the virtual optical signal to the wavelength selective switch.

[0108] 10 and 11, when a transmission fault occurs in the first branch in the submarine cable system, causing the first branch to be interrupted, the wavelength management device 700 detects the fault and then sets the wavelengths λ1 and λ2 as a first disaster tolerance set, so that the optical signals of wavelengths λ1 and λ2 are the target optical signals. Thereby, the optical generation module 710 controls to generate a virtual optical signal corresponding to the first disaster tolerance set, and the filtering and multiplexing module 720 performs power control on the virtual optical signal according to the detection result of the power detection module 730, and further performs filtering and multiplexing on the first optical signal, so that the optical signal to be transmitted to the first branch station is replaced with a virtual optical signal that does not carry data, thereby reducing the risk of data leakage.

[0109] In some embodiments, the power detection module 730 detects the power of the first optical signal and then transmits the power detection result of the first optical signal to the wavelength management device 700. When a disaster tolerance of a transmission fault occurs in the submarine cable system and a first disaster tolerance set is determined, the first disaster tolerance set is added with the optical signal power corresponding to the optical signal in the first disaster tolerance set, that is, the first disaster tolerance set includes the wavelength and power information of the target signal light. In this embodiment, after the filtering multiplexing module 720 receives the power of the virtual optical signal, it compares the power of the target optical signal in the first disaster tolerance set with the power of the virtual optical signal, and calculates the power of the virtual optical signal with the power of the target optical signal. If they are different, the filtering and combining module 720 can be further used to adjust the power of the virtual optical signal so that the power of the virtual optical signal is the same as the power of the target optical signal.

[0110] By adjusting the power of the virtual optical signal and the target optical signal to be the same, the power of the first optical signal does not change after replacing the target optical signal with the virtual optical signal, thereby improving the transmission stability of the submarine cable system. Illustratively, when adjusting the power of the virtual optical signal, the filtering multiplexing module 720 includes amplifying the power of the virtual optical signal and attenuating the power of the virtual optical signal.

[0111] Taking the light generating module 710 as a spontaneous emission light source and the filtering / combining module 720 as a wavelength selective switch as an example, when the spontaneous emission light source generates a virtual optical signal according to the principle of spontaneous emission amplification, the generated optical signal usually has a high power, which is higher than the power of the replaced target optical signal. Therefore, in some embodiments, the wavelength selective switch can adjust the magnitude of attenuation, and reduce the power of the virtual optical signal to the magnitude of the power in the first disaster tolerance set, thereby stabilizing the power of the optical signal transmitted in the submarine cable system, and improving the stability of the system after the disaster tolerance of the submarine cable system.

[0112] In some embodiments, the wavelength management device 700 further includes a fault detection module 740 used to detect the working state of the branch cable, the first branch station, and the first optical branching device of the first branch. During the normal operation of the submarine cable system, if the fault detection module 740 detects that any of the branch cable, the branch station, and the optical branching device has a fault, this branch has a fault and disaster tolerance needs to be performed. Similarly, after the disaster tolerance of the submarine cable system, if the fault detection module 740 detects that the branch cable, the first branch station, and the first optical branching device of the first branch are all already operating normally, the fault in the first branch is eliminated, and the wavelength management device 700 can be controlled to restore the submarine cable system to an operating state.

[0113] As can be seen from the above embodiment of the data confidentiality method, the first branch can further control the first optical branching device to perform optical path switching after disaster tolerance. Therefore, in some embodiments, the wavelength management device 700 is further used to determine the first optical branching device in response to a failure occurring in the first branch, control the first optical branching device to perform optical path switching, and transmit the optical signals corresponding to each wavelength in the first disaster tolerance set to the second terminal station.

[0114] As shown in Figure 9, during normal operation of the submarine cable system, the optical path state of the optical branching device is in a state of interconnection of three ports, and as shown in Figures 10 and 11, after a transmission failure occurs in the first branch, the wavelength management device 700 controls the optical branching device to switch the optical path to a state in which the first terminal station and the second terminal station are directly connected.

[0115] Furthermore, after the fault in the first branch is eliminated, the first optical branching device can be further controlled to make the first branch conductive, and the data transmission function of the first branch can be restored. Therefore, the wavelength management device 700 is further used to stop filtering and removing the target optical signal in the first optical signal, stop generating the virtual optical signal, and control the first optical branching device to switch the optical path and transmit the target optical signal to the first branch station in response to the fault being eliminated in the first branch.

[0116] In some embodiments, the wavelength management device 700 further comprises a first terminal station that transmits an optical signal to each branch station. and determining a disaster tolerance set corresponding to each optical branching device based on the wavelengths used by the first terminal station to transmit optical signals to each branch station, where the disaster tolerance set corresponding to each optical branching device includes at least one wavelength used by the first terminal station to transmit optical signals to the branch station connected to the optical branching device.

[0117] It should be understood that the process of determining the disaster tolerance set corresponding to each optical branching device is to obtain the disaster tolerance set corresponding to each optical branching device by establishing a correspondence relationship between the optical signals of different wavelengths transmitted by the first terminal station and different branch stations when the submarine cable system is in a normal operation or non-operation state. After determining the disaster tolerance set corresponding to each optical branching device, when a fault occurs in the first branch in the submarine cable system, the first optical branching device corresponding to the first branch can determine the corresponding disaster tolerance set as the first disaster tolerance set.

[0118] In some embodiments of the present application, a plurality of wavelength management devices 700 may be installed, and one wavelength management device 700 may be installed at the output end of each terminal and branch station in the submarine cable system, thereby providing each station with a corresponding data security function. For example, as shown in Figure 12, one wavelength management device 700 is installed at the output end of each of the first terminal and the second terminal, among which, the wavelength management device 700a is installed at the output end of the first terminal, and the wavelength management device 700b is installed at the output end of the second terminal. When a failure occurs at a branch station in the submarine cable system, the wavelength management device 700a replaces an optical signal in the optical signal output by a first terminal station, which should be downlinked to the branch station, with a virtual optical signal, and the wavelength management device 700b replaces an optical signal in the optical signal output by a second terminal station, which should be downlinked to the branch station, with a virtual optical signal; when a first terminal station failure occurs in the submarine cable system, the wavelength management device 700b adjusts the optical branching device to a mode for interconnection between the branch station and the second terminal station, and replaces an optical signal in the optical signal output by the second terminal station, which should be sent to the first terminal station, with a virtual optical signal; when a second terminal station failure occurs in the submarine cable system, the wavelength management device 700a adjusts the optical branching device to a mode for interconnection between the branch station and the first terminal station, and replaces an optical signal in the optical signal output by the first terminal station, which should be sent to the second terminal station, with a virtual optical signal, thereby preventing data leakage.

[0119] As shown in Figures 13 and 14, in some embodiments of the present application, two or more branch stations are installed in the trunk of a submarine cable system, and each branch station corresponds to one optical branching device. In the figures, an example is described in which two branch stations are installed in the submarine cable system, of which the two branch stations are branch station a and branch station b, respectively, and the two optical branching devices are BUa and BUb, respectively, and branch station a is connected to BUa, branch station b is connected to BUb, and the first terminal station emits wavelengths with wavelengths λ1 to λ2. n The wavelength of the optical signal received and transmitted by branch station a is λ i The wavelength of the optical signal received and transmitted by branch station b is λ j where i and j are greater than or equal to 1 and less than or equal to n, and i and j are different.

[0120] As shown in FIG. 13, during normal operation of the submarine cable system, the wavelengths emitted by the first terminal station are λ1 to λ n When an optical signal passes through BUa, it has a wavelength of λ i At the same time, the optical signal of wavelength λ i As can be seen from the above embodiment, there is a difference in the data content contained in the optical signal received by branch station a and the optical signal transmitted by branch station a. Next, when the optical signal passes through BUb, the wavelength of the signal becomes λ j The optical signal with wavelength λ is down-streamed to branch station b, and at the same time, branch station b receives j The optical signal is transmitted to BUb and the wave is up-streamed. Before the optical signal sent from one terminal station is transmitted to the second terminal station, data that needs to be kept confidential is replaced with a downlink at the branch station, thereby reducing data leakage in the submarine cable system. Therefore, during normal operation of the submarine cable system, the wavelength management device 700 does not manipulate the optical signal sent from the first terminal station, and the wavelength management device 700 only plays a role in detecting faults in the system.

[0121] When a transmission fault in a branch is detected in the undersea cable system, as shown in FIG. 14, the wavelength management device 700 detects and acquires the fact that a transmission fault has occurred in the branch in which the branch station a is located, interrupts the communication connection between the branch station a and BUa, and resets the wavelength of the optical signal sent by the first terminal station to λ i Since the optical signal having a wavelength of λ 1 is down-waved by BUa to branch station a and cannot be received or modulated, the wavelength management device 700 switches the optical path of BUa to a direct connection mode between the first terminal station and the second terminal station, and changes the wavelength of the optical signal sent by the first terminal station to λ 1 . i The optical signal with wavelength λ is replaced by a virtual signal light that does not carry data. i In this embodiment, the data in the optical signal corresponding to the branch station a is prevented from being transmitted to the second terminal station, thereby improving the confidentiality of the submarine cable system. Similarly, when a transmission failure occurs in the branch corresponding to the branch station b, the processing method is the same as the above steps, and the optical branching device and the optical signal corresponding to the branch station a are changed to the optical branching device and the optical signal corresponding to the branch station b, and the description thereof is omitted in this embodiment.

[0122] As can be seen from the contents of the above embodiments, the present application provides a method for maintaining data confidentiality after a failure in a submarine cable system and a submarine cable system, the method including the steps of: determining a first disaster tolerance set in response to a failure occurring in a first branch; and replacing a target optical signal in a first optical signal with a virtual optical signal, wherein the first branch is any branch in the submarine cable system, the first disaster tolerance set includes at least one wavelength used by the first terminal station to transmit an optical signal to the first branch, the first optical signal is an optical signal output by the first terminal station, the target optical signal includes optical signals corresponding to each wavelength in the first disaster tolerance set, and the virtual optical signal is an optical signal that does not carry data content. The method involves, when a fault occurs in a branch in the submarine cable system to perform disaster tolerance, determining the wavelength of the optical signal to be transmitted to the first branch, and replacing it with a virtual optical signal that does not carry data information, so that after the submarine cable system has achieved disaster tolerance, the optical signal of the first branch will not be transmitted to other stations, thereby improving the transmission stability of the submarine cable system after disaster tolerance has been achieved, and reducing the risk of data leakage.

[0123] Similar parts between the embodiments provided in this application may be referred to each other, and the specific embodiments provided above are merely some examples in the overall concept of this application, and do not limit the scope of protection of this application. Any other embodiments extended based on the solutions of this application by those skilled in the art without creative effort are all within the scope of protection of this application.

Claims

1. A data confidentiality maintaining method after a fault in a submarine cable system, which is applied to a submarine cable system, the submarine cable system including a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable, each of the optical branching devices being connected to one branch, each of the branches including a branch submarine cable connected to the optical branching device, and a branch station connected to the branch submarine cable, determining a first disaster tolerance set in response to a failure occurring in a first branch, the first branch being any branch in the submarine cable system, the first disaster tolerance set including at least one wavelength used by a first terminal station to transmit an optical signal to a first branch station, the first branch station being a branch station in the first branch; and a step of replacing a target optical signal in a first optical signal with a virtual optical signal, wherein the first optical signal is an optical signal output by a first terminal station, the target optical signal includes optical signals corresponding to each wavelength in the first disaster tolerance set, the virtual optical signal is an optical signal not carrying data content, and a wavelength of the virtual optical signal is the same as that of the target optical signal.

2. The step of replacing a target optical signal in a first optical signal with a virtual optical signal comprises: filtering out the target optical signal in the first optical signal to obtain a first filtered optical signal; generating the virtual optical signal; 2. The method for maintaining data confidentiality after a fault in a submarine cable system according to claim 1, further comprising the step of: multiplexing said first filtered optical signal with said virtual optical signal and outputting the multiplexed signal.

3. After the step of generating the virtual optical signal, determining a power of the target optical signal and a power of the virtual optical signal; 3. The method for maintaining data confidentiality after a fault in a submarine cable system according to claim 2, further comprising the step of: if the power of the virtual optical signal is different from the power of the target optical signal, adjusting the power of the virtual optical signal so that the power of the virtual optical signal becomes the same as the power of the target optical signal.

4. The step of replacing a target optical signal in a first optical signal with a virtual optical signal comprises: determining a first optical branching device in response to a failure occurring in the first branch, the first optical branching device being an optical branching device connected to the first branch; 2. The method for maintaining data confidentiality after a fault in a submarine cable system according to claim 1, further comprising the step of controlling said first optical branching device to perform optical path switching and transmitting optical signals corresponding to each wavelength in said first disaster tolerance set to a second terminal station.

5. After the step of controlling the first optical branching device to switch optical paths and transmitting optical signals corresponding to each wavelength in the first disaster tolerance set to a second terminal station, in response to a fault clearing occurring in the first branch, stopping filtering out the target optical signal in the first optical signal and stopping generating the virtual optical signal; 5. The method for maintaining data confidentiality after a fault in a submarine cable system according to claim 4, further comprising the step of controlling said first optical branching device to perform optical path switching and transmitting said target optical signal to said first branch station.

6. prior to the step of determining a first disaster tolerance set in response to a failure occurring in a first branch, determining wavelengths to be used by said first terminal station to transmit optical signals to each of said branch stations; 2. The method for maintaining data confidentiality after a fault in a submarine cable system according to claim 1, further comprising: a step of determining a disaster tolerance set corresponding to each of the optical branching units based on wavelengths used by the first terminal station to transmit optical signals to each of the branch stations, the disaster tolerance set corresponding to each of the optical branching units including at least one wavelength used by the first terminal station to transmit optical signals to the branch station connected to the optical branching unit.

7. 7. The method for maintaining confidentiality of data after a fault in a submarine cable system according to claim 1, wherein the occurrence of a fault in the first branch includes at least one of the following: a fault in a branch submarine cable in the first branch, a fault in the first branch station, and a fault in a first optical branching device.

8. A submarine cable system including a first terminal station, a second terminal station, a trunk submarine cable connected between the first terminal station and the second terminal station, and at least one optical branching device installed on the trunk submarine cable, each of the optical branching devices being connected to one branch, each of the branches including a branch submarine cable connected to the optical branching device, and a branch station connected to the branch submarine cable, Further comprising a wavelength management device installed on the output side of the first terminal station, The wavelength management device is used to determine a first disaster tolerance set and replace a target optical signal in the first optical signal with a virtual optical signal in response to a failure occurring in the first branch; The first branch is any branch in the submarine cable system, the first disaster tolerance set includes at least one wavelength used by a first terminal station to transmit an optical signal to a first branch station, and the first branch station is a branch station in the first branch; 1. A submarine cable system comprising: a first optical signal output from a first terminal station; a target optical signal including optical signals corresponding to each wavelength in the first disaster tolerance set; a virtual optical signal that does not carry data content; and a wavelength of the virtual optical signal that is the same as the wavelength of the target optical signal.

9. The wavelength management device includes: an optical generating module for generating the virtual optical signal; 9. The submarine cable system according to claim 8, further comprising: a filtering and multiplexing module used for filtering out the target optical signal in the first optical signal to obtain a first filtered optical signal, and for multiplexing the first filtered optical signal with the virtual optical signal for output.

10. The wavelength management device includes: a power detection module for determining a power of the target optical signal and a power of the virtual optical signal; The filtering and combining module further adjusts the power of the virtual optical signal if the power of the virtual optical signal is different from the power of the target optical signal; 10. The submarine cable system according to claim 9, wherein a power is used to make the power of the target optical signal the same as the power of the target optical signal.

11. The wavelength management device further comprises: determining a first optical branching device in response to a failure occurring in the first branch; and A control circuit for controlling the first optical branching device to perform optical path switching and transmit optical signals corresponding to each wavelength in the first disaster tolerance set to a second terminal station; 9. The submarine cable system according to claim 8, wherein the first optical branching device is an optical branching device connected to the first branch.

12. The wavelength management device further comprises: in response to fault clearance occurring in the first branch, to stop filtering out the target optical signal in the first optical signal and to stop generating the virtual optical signal; and 12. The submarine cable system according to claim 11, characterized in that the submarine cable is used to control the first optical branching device to perform optical path switching and transmit the target optical signal to the first branch station.

13. The wavelength management device further comprises: for the first terminal station to determine the wavelengths to be used for transmitting optical signals to each of the branch stations; and the first terminal station is used to determine a disaster tolerance set corresponding to each of the optical branching devices based on a wavelength used to transmit an optical signal to each of the branch stations; 9. The submarine cable system according to claim 8, wherein the disaster tolerance set corresponding to each of the optical branching devices includes at least one wavelength used by the first terminal station to transmit an optical signal to the branch station connected to the optical branching device.

14. The wavelength management device includes: The submarine cable system according to any one of claims 8 to 13, further comprising a fault detection module used to detect the operating status of the branch cable of the first branch, the first branch station and the first optical branching device.

Images