CN116781151B

CN116781151B - Spectrum detection method and system for submarine cable system

Info

Publication number: CN116781151B
Application number: CN202311040177.XA
Authority: CN
Inventors: 秦晓勇; 许昌武; 李建苹; 杨礼; 王彦溥
Original assignee: Huahai Communication Technology Co ltd
Current assignee: Huahai Communication Technology Co ltd
Priority date: 2023-08-18
Filing date: 2023-08-18
Publication date: 2023-10-20
Anticipated expiration: 2043-08-18
Also published as: GB202316045D0; CN116781151A

Abstract

The application discloses a spectrum detection method and a system of a submarine cable system, which are applied to the submarine cable system comprising a plurality of stations, submarine cables and a plurality of optical repeaters, wherein the method comprises the following steps: the method comprises the steps of obtaining factory spectrum test data of an optical repeater and intrinsic Raman spectrum data of a submarine cable, obtaining a spectrum base line corresponding to the optical repeater according to the obtained data, obtaining a gain change model according to the factory spectrum test data, obtaining power change data through monitoring a submarine cable system, and calculating a first gain spectrum according to the power change data, the spectrum base line and the gain change model, wherein the spectrum base line comprises an input spectrum and an output spectrum in normal operation, and the first gain spectrum comprises the input spectrum and the output spectrum after power change. According to the method, when the submarine cable system has power abnormality, the spectrum after the change of each optical repeater is calculated through the gain change model, so that the input spectrum and the output spectrum corresponding to each optical repeater are obtained, and the accuracy of spectrum acquisition is improved.

Description

Spectrum detection method and system for submarine cable system

Technical Field

The application relates to the technical field of submarine cable detection, in particular to a spectrum detection method and system of a submarine cable system.

Background

The submarine cable communication system (Undersea Fiber Communication Systems) is an important communication system for connecting different countries and offshore devices through submarine cables, and spans a distance of thousands to tens of thousands of kilometers. Because the optical signal has a certain power loss when transmitted in the medium, the optical signal in the submarine cable is seriously attenuated due to the overlarge transmission distance, and therefore, an optical Repeater (RPT) is required to be arranged on the submarine cable at intervals to amplify the optical signal.

A typical optical repeater amplifier is a rare earth doped fiber amplifier, such as an Erbium doped fiber amplifier EDFA (Erbium-Doped Optical Fiber Amplifier). During the use process of the EDFA, an input optical signal is amplified and output through a pump (pump) light source, so that the transmission stability of the optical signal in a submarine cable system is maintained. In the operation process of the submarine cable system, due to factors such as pump failure, temperature change, increase of optical fiber loss in the cable and the like, the input spectrum and/or the output spectrum of the EDFA can be changed, and the transmission stability of the submarine cable system is affected.

When the submarine cable system is in operation, the transmission state of the submarine cable system can be obtained by detecting the spectral change of the EDFA. However, when the EDFA is installed in a submarine cable system, the EDFA is installed under water together with the submarine cable, and thus the spectral change in the submarine cable cannot be directly detected when a problem occurs in the submarine cable system. And by an indirect mode, for example, a coherent optical time domain reflectometer with variable wavelength is used for sending detection light into the submarine cable, so that when the spectrum change of the optical repeater in the submarine cable system is acquired, only the relative change of the spectrum can be acquired, and the accuracy is low. In addition, the method needs to occupy a plurality of service wavelength channels for acquiring the spectrum, so that when the service signals in the submarine cable are more, the wavelengths capable of being used for measuring the spectrum are less, and the accuracy of spectrum detection is affected; when the service is full, even spectral detection is not possible. Therefore, in order to meet the operational stability requirement of the submarine cable system, a spectrum detection method is needed to improve the accuracy in detecting the spectrum performance variation of each optical repeater in the submarine cable system.

Disclosure of Invention

The application provides a spectrum detection method and a system of a submarine cable system, which are used for solving the problem of lower accuracy in acquiring the spectrum change of each optical repeater in the submarine cable system.

According to a first aspect of an embodiment of the present application, there is provided a spectrum detection method of a submarine cable system, applied to the submarine cable system, the submarine cable system including a plurality of stations configured to receive and transmit optical signals, a submarine cable disposed between the plurality of stations to communicate the plurality of stations, and a plurality of optical repeaters disposed on the submarine cable, respectively, to amplify the optical signals transmitted by the stations, the method including:

acquiring first spectrum test data of a plurality of optical repeaters and second spectrum test data of a submarine cable; the first spectrum test data comprise factory spectrum test data of each optical repeater, and the second spectrum test data comprise intrinsic Raman spectrum data of the submarine cable; acquiring a spectrum baseline corresponding to each optical repeater according to each first spectrum test data and each second spectrum test data; the spectrum base line comprises an input spectrum and an output spectrum of each optical repeater after the submarine cable system inputs an optical signal with preset power; acquiring a gain variation model corresponding to each optical repeater according to each first spectrum test data; the gain variation model comprises gain data of the optical repeater for optical signals with different wavelengths and/or different powers; monitoring the submarine cable system to obtain power variation data; calculating a first gain spectrum according to the power change data, the spectrum baseline and the gain change model; the first gain spectrum includes an input spectrum and an output spectrum of each optical repeater after a power change of the optical signal in the submarine cable system.

According to the method, after first spectrum test data of each optical repeater and second spectrum test data of a submarine cable are obtained, a spectrum base line corresponding to each optical repeater is calculated through the first spectrum test data and the second spectrum test data, gain data of different wavelengths and different powers of each optical repeater are obtained through the first spectrum test data, a gain change model corresponding to each optical repeater is obtained, and when power change occurs in the submarine cable system, input and output spectrums of each optical repeater after the power change can be calculated according to the power change data, the spectrum base line and the gain change model, so that a first gain spectrum is obtained. Through the process, after the power of the submarine cable system is changed, the input spectrum and the output spectrum of each affected optical repeater can be obtained through calculation, so that the gain spectrum of each optical repeater in the submarine cable system is obtained, and the accuracy of spectrum acquisition is improved.

In one possible embodiment, obtaining a spectral baseline corresponding to each optical repeater from each of the first spectral test data and the second spectral test data comprises: acquiring power information corresponding to the wavelength range of an input optical signal of the submarine cable system and signals with different wavelengths; according to the wavelength range and the power information, acquiring a loss spectrum of the submarine cable to the input optical signal and a gain spectrum of each optical repeater to the input optical signal; and determining a loss spectrum and a gain spectrum corresponding to the input optical signal as a spectrum baseline. In this way, the spectrum base line of the optical signal in the submarine cable system can be obtained by obtaining the gain data of the optical signal and the loss data of the submarine cable in the normal operation process of the submarine cable system, so that the spectrum data in the normal operation process of the submarine cable system can be determined, and when the submarine cable system has faults affecting the spectrum data, the spectrum base line can be updated rapidly, so that the spectrum calculation efficiency is improved.

In one possible embodiment, obtaining a gain variation model corresponding to each optical repeater from each first spectral test data includes: gain data of optical signals with different wavelengths and/or different powers of each optical repeater are obtained according to the first spectrum test data; and determining a gain change model corresponding to each optical repeater according to the gain data corresponding to each optical repeater. By determining the gain change model, after the submarine cable system fails to influence the transmission of the optical signals, the input spectrum and the output spectrum corresponding to each optical repeater can be obtained through calculation according to the changed power data, and the accuracy of spectrum acquisition is improved.

In one possible embodiment, monitoring a submarine cable system to obtain power variation data includes: transmitting a first detection light with a single wavelength into the submarine cable system; acquiring a second gain spectrum of the first detection light in the submarine cable system to serve as power change data; the second gain spectrum includes an input spectrum and an output spectrum of the first detection light passing through each optical repeater; calculating a first gain spectrum from the power variation data, the spectrum baseline, and the gain variation model, comprising: if the second gain spectrum is inconsistent with the spectrum baseline, obtaining a gain difference value between the second gain spectrum and the spectrum baseline; a first gain spectrum is calculated based on the gain difference and the gain variation model. Therefore, the first gain spectrum can be calculated by sending the detection light with single wavelength to the submarine cable system, and the number of the traffic channels occupied when the power in the submarine cable system is monitored is reduced, so that the influence on the transmission efficiency of the submarine cable system when the spectrum detection is carried out is reduced.

In one possible embodiment, if the second gain spectrum does not match the spectrum baseline, obtaining a gain difference between the second gain spectrum and the spectrum baseline includes: extracting gain spectrum information in a spectrum baseline; the gain spectrum information includes an input spectrum and an output spectrum of the optical signal corresponding to the first detected light wavelength in the spectrum baseline through each optical repeater; and comparing the second gain spectrum with the gain spectrum information to obtain a gain difference value. And calculating the gain difference value of each optical repeater through the corresponding relation between each optical repeater and the spectrum base line and the second gain spectrum, so that the spectrum change data of the submarine cable system is obtained, and the accuracy of spectrum acquisition is improved.

In one possible embodiment, the second gain spectrum includes a second input spectrum and a second output spectrum, the gain spectrum information includes an input gain spectrum and an output gain spectrum, the gain difference includes an input gain difference and an output gain difference, and comparing the second gain spectrum with the gain spectrum information to obtain the gain difference includes: calculating a difference value between a second input spectrum and an input gain spectrum corresponding to each optical repeater to obtain an input gain difference value; calculating the difference value of the second output spectrum and the output gain spectrum corresponding to each optical repeater to obtain an output gain difference value; and arranging the input gain difference value and the output gain difference value corresponding to each optical repeater in the receiving-transmitting sequence of each optical repeater to obtain the gain difference value. By acquiring and arranging the input gain difference value and the output gain difference value, the input spectrum and the output spectrum of each optical repeater can be calculated through a gain change model, and the spectrum acquisition efficiency is improved.

In one possible embodiment, after comparing the second gain spectrum with the gain spectrum information to obtain the gain difference, the method further includes: detecting each input gain difference value and each output gain difference value in the gain difference values to obtain first difference value data with a first value larger than or smaller than a preset value; if the first difference value data is an input gain difference value, the fault area of the submarine cable system is a submarine cable connected with the input end of the first optical repeater; the first optical repeater is an optical repeater corresponding to the first difference data; if the first difference data is an output gain difference, the fault area of the submarine cable system is the first optical repeater. By the category of the first gain difference value, the position of the area where the submarine cable system breaks down can be determined, so that the fault can be conveniently checked and maintained.

In one possible embodiment, calculating the first gain spectrum from the gain difference and the gain variation model includes:

determining a second optical repeater in the submarine cable system according to the position of the first optical repeater; the second optical repeater comprises each optical repeater connected with the output end of the first optical repeater through a submarine cable; and calculating the input spectrum and the output spectrum of each second optical repeater according to the gain difference value and the gain change model corresponding to the second optical repeater so as to obtain a first gain spectrum. After the fault position of the submarine cable system is obtained, the input and output spectrums of each optical repeater connected with the fault position in a subsequent mode can be calculated, so that spectrum change of the submarine cable system is obtained, the calculated quantity is reduced, and spectrum acquisition efficiency is improved.

In one possible embodiment, after calculating the first gain spectrum, the method further comprises: the first gain spectrum is displayed. Therefore, the information such as the fault position and the fault factor of maintenance personnel can be prompted through displaying the spectrum change, and the maintenance of the submarine cable system is facilitated.

According to a second aspect of the embodiments of the present invention, there is provided a spectrum detection system of a submarine cable system for performing a spectrum detection method of any one of the foregoing submarine cable systems, the submarine cable system including a plurality of stations configured to receive and transmit optical signals, a submarine cable disposed between the plurality of stations to communicate with the plurality of stations, and a plurality of optical repeaters disposed in the submarine cable system to amplify the optical signals transmitted from the stations, the system including a network management device disposed in one of the stations and connected to the other stations, and a submarine cable monitoring device connected to the submarine cable, wherein the network management device is connected to the submarine cable monitoring device, wherein:

the network management device includes: a data acquisition unit configured to: acquiring first spectrum test data of a plurality of optical repeaters and second spectrum test data of a submarine cable; a processing calculation unit configured to: acquiring a spectrum baseline corresponding to each optical repeater according to each first spectrum test data and each second spectrum test data; acquiring a gain variation model corresponding to each optical repeater according to each first spectrum test data; a submarine cable monitoring device configured to: monitoring the submarine cable system to obtain power variation data; the processing computing unit is further configured to: a first gain spectrum is calculated based on the power variation data, the spectrum baseline, and the gain variation model.

The method comprises the steps that a network management device and a submarine cable monitoring device are respectively arranged in a submarine cable system, wherein the submarine cable monitoring device can monitor the submarine cable system to obtain power change data of the submarine cable system, the network management device can acquire and process first spectrum test data and second spectrum test data to obtain spectrum baselines of the submarine cable system and gain change models corresponding to optical repeaters, and therefore gain spectrums corresponding to each optical repeater are calculated after power change occurs in the submarine cable system, and accuracy of the obtained gain spectrums is improved.

In a possible embodiment, the network management device further comprises a spectrum display unit configured to display the first gain spectrum. By arranging the spectrum display unit in the network management device, the first gain spectrum can be displayed after the first gain spectrum is obtained through calculation, so that maintenance personnel are reminded of maintaining the submarine cable system.

As can be seen from the above technical solution, the present application provides a method and a system for detecting spectrum of a submarine cable system, which are applied in a submarine cable system including a plurality of stations, submarine cables and a plurality of optical repeaters, the method includes: acquiring first spectrum test data and second spectrum test data, acquiring a spectrum baseline corresponding to each optical repeater according to the acquired data, acquiring a gain change model corresponding to each optical repeater according to each first spectrum test data, acquiring power change data by monitoring a submarine cable system, and calculating a first gain spectrum according to the power change data, the spectrum baseline and the gain change model, wherein the first spectrum test data comprises factory spectrum test data of each optical repeater, and the second spectrum test data comprises intrinsic Raman spectrum data of a submarine cable; the spectrum baseline comprises input and output spectrums of the submarine cable system in normal operation, the gain change model comprises gain data of optical repeaters on optical signals with different wavelengths and/or different powers, and the first gain spectrum comprises the input spectrum and the output spectrum of each optical repeater after the power of the optical signals in the submarine cable system is changed. According to the method, when the transmission power of the submarine cable system is abnormal, the spectrum after the change of each optical repeater is calculated through the gain change model, so that the input spectrum and the output spectrum corresponding to each optical repeater are obtained, and the accuracy of spectrum acquisition is improved.

Drawings

In order to more clearly illustrate the technical solution of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic diagram of measurement wavelengths of COTDR;

FIG. 2 is a schematic flow chart of a spectrum detection method of a submarine cable system according to an embodiment of the application;

FIG. 3a is a schematic diagram of a loss spectrum of a submarine cable according to an embodiment of the present application;

FIG. 3b is a schematic diagram of a loss spectrum of another submarine cable according to an embodiment of the application;

FIG. 3c is a schematic diagram of a gain spectrum of an optical repeater according to an embodiment of the present application;

FIG. 3d is a schematic gain spectrum diagram of an optical repeater and submarine cable according to an embodiment of the present application;

FIG. 4 is a schematic flow chart of acquiring a spectrum baseline according to an embodiment of the application;

FIG. 5 is a schematic diagram of an optical repeater in accordance with the present application;

FIG. 6 is a flowchart of a gain variation model according to an embodiment of the present application;

FIG. 7a is a schematic diagram of a fault in a gain variation model according to an embodiment of the present application;

FIG. 7b is a schematic diagram of another fault in the gain variation model according to an embodiment of the present application;

FIG. 7c is a schematic diagram of yet another failure in the gain variation model in accordance with an embodiment of the present application;

FIG. 7d is a schematic diagram of another failure in the gain variation model in accordance with an embodiment of the present application;

FIG. 7e is a schematic diagram of another failure in the gain variation model in accordance with an embodiment of the present application;

FIG. 8 is a schematic flow chart of a submarine cable monitoring system according to an embodiment of the application;

FIG. 9 is a flow chart of obtaining gain differences according to an embodiment of the present application;

FIG. 10 is a schematic diagram of a second gain spectrum after loss failure of the submarine cable system according to an embodiment of the application;

FIG. 11 is a schematic diagram of a second gain spectrum after pump failure in a submarine cable system according to an embodiment of the application;

FIG. 12 is a schematic diagram of a submarine cable system according to an embodiment of the application;

fig. 13 is a schematic structural diagram of a spectrum detection system of a submarine cable system according to an embodiment of the application.

Detailed Description

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the application. Merely exemplary of apparatus and methods consistent with some aspects of the application as set forth in the claims.

In the embodiment of the application, the submarine cable system, namely the submarine cable system, refers to a communication network system formed by a plurality of communication cables. The communication cables in the system are laid on the sea floor and may therefore be referred to as sea lines. The submarine cable line can transmit optical communication signals between the end stations, so that a communication function of a cross-sea area is realized. Submarine cable systems may enable long-range communications, for example, data communications may be accomplished across tens of thousands of kilometers of the ocean. It should be noted that the submarine cable system in the embodiment of the present application may also be used in relatively short-distance communication areas such as river crossing and lake crossing.

Because of the rapid innovation speed of technical development in the communication field, in order to enable the submarine Cable system to apply the latest site transmission equipment, the submarine Cable system is constructed by adopting an Open Cable architecture, namely an Open submarine Cable network. In the Open Cable architecture, the station equipment is decoupled from the underwater equipment, so that the submarine Cable system can replace station transmission equipment of different manufacturers under the condition that the underwater equipment is not replaced, the updating cost of the submarine Cable system is reduced, and the flexibility of the submarine Cable system is improved. Meanwhile, due to the development of an Open Cable architecture, the overall transmission performance of the submarine Cable system is monitored, and the acquisition of input and output spectrums of the submarine Cable system becomes an important means for detecting the operation of the submarine Cable system.

In some embodiments, the submarine cable system includes a station facility located on the surface of the water and submarine cables and subsea equipment located subsea. The station equipment is used for sending and receiving optical signals, the submarine cable is used for transmitting the optical signals, and the underwater equipment can achieve the functions of gain of the optical signals, branching of the submarine cable and the like. The optical signals sent by the station equipment are transmitted in the medium to have certain attenuation, and when the submarine cable is connected with the underwater equipment, the submarine equipment has certain insertion loss, so that the optical repeater for amplifying the optical signals is included in the underwater equipment, and the loss of the power of the submarine cable and the submarine equipment on the optical signals in the long-distance transmission process is reduced.

It should be noted that, in order to be able to carry more data, the optical signal sent by the station device is a composite signal of multiple wavelength signals within a band, taking a C band commonly used in a submarine cable system as an example, the wavelength range of the optical signal is distributed between 1530nm and 1568nm, where multiple wavelengths λ1 to λn may be subdivided, and be used to refer to any wavelength within the C band.

Thus, in some embodiments, the input and output spectral conditions of the submarine cable system may be detected by a variable wavelength COTDR sweep. The COTDR is Coherent Optical Time Domain Reflectometry, namely a coherent optical time domain reflectometer, specifically, the COTDR can send a detection optical signal with a variable wavelength to a submarine cable system in an operation process, and receive a return optical signal of the detection optical signal, so as to measure an input spectrum and an output spectrum of an optical repeater in the submarine cable system. As shown in fig. 1, the wavelengths of service data transmitted in the submarine cable system are λ1 to λn, and COTDR can send optical signals with wavelengths of λ3, λ5 and λ7 respectively, and receive return light of the three optical signals with different wavelengths, so as to obtain spectral data of the optical signals with wavelengths of λ3, λ5 and λ7 in the submarine cable system. The spectrum data of the transmitted detection light signals can only be obtained by the COTDR, so that the more the wave numbers of the detection light signals transmitted by the COTDR are, the more the obtained spectrum is clear, but the service carrying capacity of the submarine cable system is reduced due to the fact that the detection light signals need to occupy a service light signal transmission channel, and when the service in the submarine cable system is full, the detection light signals cannot be transmitted to the submarine cable system and spectrum information cannot be obtained, so that the spectrum obtained by the COTDR measurement is only the relative change condition of one or a plurality of wave band spectrums, and the input and output spectrum data of each optical repeater cannot be reflected.

It should be understood that the spectral information in a submarine cable system represents a sequence of optical power levels for each wavelength in a wavelength order, including two dimensions of power level and slope level. Because the product of the wavelength and the frequency of the optical signal is the light velocity, the optical signal of each wavelength has a corresponding optical power, and when in the same medium, the higher the frequency of the optical signal is, the shorter the wavelength is, so the spectrum information can also represent the sequence of the optical power corresponding to each wavelength arranged according to the frequency sequence. For the input spectrum and the output spectrum of the underwater equipment in the submarine cable system, subtracting the input spectrum from the output spectrum is the gain spectrum corresponding to the underwater equipment, when the underwater equipment has the function of signal amplification, the gain spectrum is positive gain, and when the underwater equipment has the function of signal attenuation, the gain spectrum is negative gain.

The gain value of the optical repeater to the power can be calculated by calculating the power ratio of the output power to the input power, and then calculating the logarithm of the power ratio which is 10 times and is 10 as the bottom power ratio, wherein the unit is dB, the gain value can be positive or negative, the positive value represents the gain, and the negative value represents the loss. For example, when the power ratio is 1, i.e., the input power is the same as the output power, the signal has no gain nor loss, and the gain is 0dB; when the power ratio is 2, the gain is about 3dB; when the power ratio is 1/2, the gain is about-3 dB. On the basis, when the power ratio is 2 ⁿ When n is an integer, the gain value of the obtainable power is 3ndB.

The application provides a spectrum detection method of a submarine cable system, which is applied to the submarine cable system.

It should be noted that, since the optical repeater in the submarine cable system has an upper limit on the gain of the optical signal, when the submarine cable in the submarine cable system is long, a plurality of optical repeaters may be disposed on the submarine cable to amplify the optical signal so that the power of the optical signal transmitted in the submarine cable is not too low. In some embodiments, the lengths of the sea cables between two adjacent optical repeaters are the same, for example, one optical repeater is disposed on the sea cable at intervals of 100km for optical signal gain, where the intervals of 100km are only an exemplary illustration, and the intervals of the optical repeaters are related to the loss of the optical signal of the sea cable and the gain power of the optical repeater itself.

On the basis of application in the submarine cable system, as shown in fig. 2, the method comprises the following steps:

s210: first spectrum test data of a plurality of optical repeaters and second spectrum test data of submarine cables are obtained.

The first spectrum test data comprise factory spectrum test data of each optical repeater, and the second spectrum test data comprise intrinsic Raman spectrum data of the submarine cable. It should be understood that the factory spectrum test data of the optical repeater should include gain information of the optical repeater on optical signals with different wavelengths and different powers, and specifically, the factory spectrum test data of the optical repeater may obtain the gain effects of the optical signals with different wavelengths and different powers through testing the optical repeater in the factory stage, so as to obtain the factory spectrum test data. The intrinsic raman spectrum data of the submarine cable is divided into an intrinsic loss spectrum and a raman loss spectrum, which can be obtained by respectively calculating an absorption spectrum and a scattering spectrum of the submarine cable, wherein the loss can be also called as negative gain.

As can be seen from the transmission properties of the optical signals, when the propagation distance and the initial power of the optical signals transmitted in the same medium are the same, the optical signals have a longer wavelength, i.e., the power loss of the optical signals with a lower frequency is smaller, and the optical signals have a shorter wavelength, i.e., the power loss of the optical signals with a higher frequency is larger. Therefore, as shown in fig. 3a, the loss of the optical fiber submarine cable in the submarine cable system for the optical signal is smaller for the optical signal with longer wavelength, the loss for the optical signal with shorter wavelength is larger, the intrinsic raman spectrum of the submarine cable shows negative inclination, when the submarine cable receives the signals with the same optical power among different wavelengths, the output spectrum of the submarine cable shows positive inclination, and the optical power corresponding to each wavelength is obviously reduced compared with the input optical signal.

It should be noted that, the loss of the submarine cable to the optical signal is also related to the length of the submarine cable, and the longer the submarine cable is, the larger the loss of the submarine cable to the optical signal is, and the different lengths of the submarine cables are different from each other. In some embodiments of the present application, the lengths of the submarine cables between each optical repeater are the same, that is, the submarine cable system is a standard span, so that when the submarine cable system operates normally, the loss of the submarine cable on the optical signal of each segment is consistent, and thus the input spectrum of each optical repeater is consistent, so as to reduce the problem of different gain effects of the optical repeaters caused by different input optical power. In another part of embodiments, the output spectrum of each optical repeater is the same by matching the optical repeaters with different powers or adjusting the powers of the optical repeaters in the submarine cable system in the process of setting the submarine cable system, so that the loss change of the submarine cable caused by the power change is reduced.

Therefore, in order to make the optical power of different wavelengths equal in the optical signal output by the submarine cable system, as shown in fig. 3b, the input spectrum can be negatively tilted by adjusting the optical power of different wavelengths in the input optical signal, so that the output spectrum without tilting can be output after the submarine cable is worn. It should be appreciated that the negative slope of the input spectrum corresponds to the loss of the submarine cable to the optical signal.

The optical repeater in the submarine cable system can amplify the optical signal, so that the influence of the submarine cable on the loss of the optical signal is reduced. As can be seen from fig. 3b, the optical signal with negative tilt is lost to have no tilted output spectrum after passing through a length of submarine cable, and the optical signal can be amplified by the optical repeater to improve the transmission performance of the submarine cable system. As shown in fig. 3c, the optical repeater re-acquires the output spectrum with negative tilt by amplifying the output spectrum without tilt of the submarine cable, and the submarine cable connected to the optical repeater can receive the output spectrum with negative tilt, thereby performing the process as in fig. 3b again. Thus in some embodiments of the application, the loss and gain processes shown in fig. 3b and 3c are performed alternately, as many times as the number of optical repeaters, in case the submarine cable system is operating normally. It should be understood that, in the embodiment of the present application, the output spectrum of the submarine cable connected to the input end of the optical repeater is the input spectrum of the optical repeater, and the output spectrum of the optical repeater is the input spectrum of the submarine cable connected to the output end of the optical repeater.

S220: a spectral baseline corresponding to each optical repeater is obtained from each of the first spectral test data and the second spectral test data.

The spectrum base line comprises an input spectrum and an output spectrum of each optical repeater after the submarine cable system inputs an optical signal with preset power, and the preset power is the power of the optical signal input to the submarine cable in the normal operation process of the submarine cable system. The output spectrum of the optical repeater is the input spectrum of the submarine cable connected with the output end of the optical repeater, and the input spectrum of the optical repeater is the output spectrum of the submarine cable connected with the input end of the optical repeater, so that the spectrum baseline can be the input spectrum and the output spectrum of each submarine cable after the submarine cable system inputs the optical signal with preset power.

In some embodiments of the present application, after the first spectrum test data corresponding to the optical repeater and the second spectrum test data corresponding to the submarine cable are obtained, the output spectrum of each submarine cable and the output spectrum of each optical repeater may be calculated according to the power of the optical signal input by the submarine cable system and the length of each submarine cable, so as to obtain a spectrum baseline. For example, as shown in fig. 3d, during normal operation of the submarine cable system, the input spectrum of the optical signal may be sequentially calculated, in order of signal transmission, from the output spectrum after loss in the submarine cable and the output spectrum after gain in the optical repeater, so as to obtain a spectrum baseline.

Illustratively, in some embodiments, as shown in fig. 4, the step of obtaining a spectral baseline may be:

s221: and acquiring the power information corresponding to the wavelength range of the input optical signal of the submarine cable system and the signals with different wavelengths.

Firstly, signals with all wavelengths and power information corresponding to different wavelengths, which are included in an input optical signal of a submarine cable system, need to be acquired, and because the loss of the submarine cable to the optical signal is influenced by the wavelength of the optical signal, the power of the short-wavelength optical signal in the input optical signal is higher, and the power of the long-wavelength optical signal is lower.

It should be understood that the information of the input optical signal may be directly obtained by the device that transmits the optical signal, and in this embodiment of the present application, when the optical signal is transmitted by the station device in the submarine cable system, the spectrum of the transmitted optical signal may be stored, so as to facilitate subsequent obtaining.

S222: and according to the wavelength range and the power information, acquiring a loss spectrum of the submarine cable to the input optical signal and a gain spectrum of each optical repeater to the input optical signal.

After the wavelength range and the power of the input optical signal are obtained, the loss spectrum of the submarine cable to the input optical signal can be obtained according to the loss condition of the submarine cable to the signals with different wavelengths in the second spectrum test data, and then the output spectrum of a submarine cable can be obtained according to the loss spectrum and the input spectrum. And then according to the gain condition of the optical repeater to the optical signal in the first spectrum test data, obtaining the gain spectrum of the optical repeater to the input optical signal, thereby amplifying the power of the input optical signal which is lost by the submarine cable.

As shown in fig. 3d, transmitted as an optical signal to the RPT _m-1 For example, where RPT represents an optical repeater, m is any positive integer greater than 1. When the optical signal is lost by a section of submarine cable, a spectrum with a slope of 0 is output to the RPT _m-1 In RPT _m-1 Amplifying an optical signal, gain spectrum and RPT _m-1 And RPT _m The loss spectrum of the submarine cable between the two is the same, so that the submarine cable is transmitted to the RPT _m The slope of the spectrum of the optical signal of (c) is still 0.

S223: and determining a loss spectrum and a gain spectrum corresponding to the input optical signal as a spectrum baseline.

And determining a spectrum baseline of the submarine cable system according to the connection sequence of the submarine cable and the optical repeater by using the gain spectrum corresponding to each optical repeater and the loss spectrum corresponding to each submarine cable.

In some embodiments, the spectral baselines may further include an input spectrum and an output spectrum of each optical repeater and an input spectrum and an output spectrum of each segment of the submarine cable after substituting the input spectrum of the optical signal into the gain spectrum and the loss spectrum. It should be noted that, the power and the slope of the optical signal in the spectrum baseline are the nominal power and the nominal slope of the submarine cable system, respectively.

According to the scheme, in the normal operation process of the submarine cable system, the gain data of the optical signals and the loss data of the submarine cable in the optical signals can be obtained by each optical repeater, so that the spectrum base line of the optical signals in the submarine cable system is obtained, the spectrum data of the submarine cable system in the normal operation process can be determined, when the submarine cable system has faults affecting the spectrum data, the spectrum base line can be updated rapidly, and the spectrum calculation efficiency is improved.

S230: gain variation models corresponding to each optical repeater are obtained according to each first spectrum test data.

Wherein the gain variation model comprises gain data of the optical repeater for optical signals of different wavelengths and/or different powers. In the embodiment of the present application, the optical repeater applied to the submarine cable system is an EDFA, and as shown in fig. 5, the EDFA at least includes a pump light source, an optical coupler, an optical isolator, an erbium-doped fiber and an optical filter. During the use process of the EDFA, pumping light is emitted by a pumping light source to excite erbium particles in the erbium-doped optical fiber to a high energy level, and when an input optical signal passes through the erbium-doped optical fiber, the particles with the high energy level return to a ground state from the excited state, so that the input optical signal is amplified, and gain is generated.

In some embodiments, as shown in fig. 6, the process of obtaining the gain variation model may include:

s231: gain data for optical signals of different wavelengths and/or different powers for each optical repeater is obtained from the first spectral test data.

Since the first spectrum test data includes gain data of the optical repeaters for optical signals with different wavelengths and/or different powers, the gain data corresponding to each optical repeater can be directly obtained through the first spectrum test data. It will be appreciated that since the gain data of an EDFA for an optical signal is related to the input spectrum, there is corresponding gain data for each optical signal power in the input spectrum.

S232: and determining a gain change model corresponding to each optical repeater according to the gain data corresponding to each optical repeater.

After gain data of each optical repeater on optical signals with different wavelengths and/or different powers are obtained, the gain change model can be determined by counting the gain data of the optical signals with different wavelengths under the condition of different powers, so that when loss in a submarine cable system is increased or the power of the optical signals is abnormal, the changed gain data is obtained through calculation of the gain change model.

Since the gain data of an optical signal by an EDFA is related to the power of the optical signal, the variation of the input spectrum to the EDFA and the failure of the EDFA itself become the sources of problems of gain anomalies in a submarine cable system, and these failures also become the cause of the variation of the gain spectrum of the EDFA. So in some embodiments, the gain variation model may further include a variation coefficient in the submarine cable system, where the variation coefficient refers to a gain influence coefficient of the submarine cable system fault on the EDFA, and by way of example, the power value in the input spectrum and the output spectrum of each EDFA when the submarine cable system operates normally may be the nominal power, the spectral slope is the nominal slope, and when the submarine cable system fails, the influence of the submarine cable system on the gain spectrum of the EDFA includes an influence on the power value and the spectral slope, so the determination of the variation coefficient may include the following cases:

Firstly, the nominal power of the input spectrum of one EDFA in the submarine cable system is changed, and as the EDFA in the submarine cable system works in the power locking mode, as shown in fig. 7a, the gain of the EDFA on the optical signal with the changed power is larger than that on the optical signal with the nominal power, and the gains of the optical signals with different wavelengths are different, so that the slope of the output spectrum of the obtained EDFA is different from the nominal slope. Specifically, when the input spectrum of the EDFA is not the nominal power, the slope of the output spectrum of the EDFA will change with the change of the input spectrum of the EDFA, and the change coefficient is usedAnd (3) representing.

Next, as shown in fig. 7b, in the case where the input power of the EDFA in the submarine cable system is unchanged but the slope of the input spectrum is changed, the slope of the output spectrum is also changed along with the change of the slope of the input spectrum, and the slope change coefficient is usedAnd (3) representing.

In some embodiments, as shown in FIG. 7c, the power of the input spectrum of the EDFA may also occurUnder the condition that the size and the slope are changed, the change of the output spectrum needs to consider the power change and the slope change of the input spectrum at the same time, and the change coefficient is the superposition of the power change and the slope change of the input spectrum, and the power change and the slope change are usedAnd (3) representing.

In some embodiments of the present application, there is no change in the input spectrum, but the gain of the optical signal changes in the EDFA due to pump failure in the EDFA. As shown in fig. 7d, the power of the input spectrum is the nominal power, the slope is the nominal slope, the gain effect of the EDFA on the optical signal is affected by the number of pump light sources failing, the effect of pump failure is related to the total number of pump light sources in one EDFA and the number of pump failures, at this time, the power and slope of the output spectrum are both changed, and the influence coefficient on the power is available Indicating that the influence on the slope is available +.>And (3) representing. Exemplary, ->The total number of pump light sources and the number of pump failure can be directly used for calculation, and two pump light sources are arranged in the EDFA, namely pump1 and pump2 are taken as examples, when pump2 fails and pump1 works normally, the gain effect of the EDFA is approximately 1/2 of that of the original pump, and therefore the power of an output spectrum can be reduced by about 3dB.

In addition, the change of the output power of the repeater can also cause the loss spectrum of the optical fiber connected with the output end of the repeater to change, and the raman effect in the optical fiber can cause the spectrum slope to be different under different fiber-in powers. Exemplary, as shown in FIG. 7e, the higher the input optical power, the more pronounced the power transfer between different wavelengths, resulting in a larger slope change, the coefficient of change is usedAnd (3) representing.

Thus, in the gain variation model, the power variation of the spectrum in the submarine cable system can be described as:

；

wherein P is the power data of the spectrum in the submarine cable, P _base The nominal power of the optical signal is input to the submarine cable system,for the effect of EDFA on the output spectral power in case of pump failure, < +.>Is the loss of nominal power of the submarine cable to the incoming optical signal.

Whereas the slope change of the spectrum in a submarine cable system can be described as:

；

Wherein k is the slope data of the spectrum in the submarine cable, k _base Is the nominal slope of the incoming optical signal in the submarine cable system.

Since the input spectrum and the output spectrum of each EDFA need to be measured in both power and slope dimensions, the input spectrum or the output spectrum of an EDFA can be expressed as:

；

it should be understood that in some embodiments, the formula is as follows, not only for the case of communication bands λ1 to λn applied in the entire submarine cable system, but also for the case of smaller bands λi to λj therein:

；

wherein i and j are positive integers greater than or equal to 1 and less than or equal to n, and i is greater than j.

In the above embodiment, the gain change model corresponding to the optical repeater can be determined according to the fault information in the submarine cable system and the gain data of the optical repeater on different power signals, so that after the fault affecting the power of the optical signal occurs in the submarine cable system, the input spectrum and the output spectrum corresponding to each optical repeater can be obtained by calculation according to the fault and the changed power data, and the accuracy of obtaining the spectrum is improved.

S240: the submarine cable system is monitored to obtain power variation data.

The monitoring of the submarine cable system may be implemented in a plant monitoring device in a site plant of the submarine cable system. In the embodiment of the present application, the COTDR may be configured to connect with a site device, so as to implement a monitoring function of the submarine cable system, and as shown in fig. 8, an exemplary process for monitoring the submarine cable system to obtain power variation data may include:

S241: a first detection light of a single wavelength is transmitted into the submarine cable system.

In the normal operation process of the submarine cable system, the operation state of the submarine cable system can be detected by sending first detection light to the submarine cable system through the COTDR connected with the station equipment. In some embodiments of the present application, the wavelength of the first detection light is any one wavelength of the communication wavelength bands λ1 to λn used in the submarine cable system, for example λ2 or λ4, and it should be noted that the first detection light needs to occupy one wavelength of the repeater for transmission, so that the first detection light can be carried by the spare wavelength in the submarine cable system during the monitoring process, thereby achieving the purpose of transmitting the first detection light into the submarine cable system.

It should be understood that, when the first detection light is an optical signal with a shorter wavelength or a longer wavelength, if the spectrum of the submarine cable system changes, the gain spectrum changes greatly. In some embodiments, when the C-band is applied as the service band in the submarine cable system, the wavelength range of the first detection light may be selected between 1530nm to 1535nm and 1560nm to 1568 nm. The wavelength range of the first detection light is only one possible implementation, and the specific wavelength of the first detection light needs to be determined according to the occupied service wavelength in the cable system sending the first detection light Shi Hai.

S242: and acquiring a second gain spectrum of the first detection light in the submarine cable system as power change data.

Wherein the second gain spectrum comprises an input spectrum and an output spectrum of the first detection light as it passes through each optical repeater. After the first detection light is sent into the submarine cable system, the COTDR needs to acquire the return light of the first detection light, so as to acquire the transmission state of the first detection light in the submarine cable system through the return light. Therefore, in some embodiments of the present application, the second gain spectrum may be a spectrum of the returned light of the first detection light, if the spectrum of the returned light accords with the spectrum baseline, the transmission of the submarine cable system is normal, and if the spectrum of the returned light does not accord with the spectrum baseline, the transmission of the submarine cable system is abnormal.

In the above embodiment, the COTDR is set to send the first detection light, so as to obtain the transmission state in the submarine cable system, so as to determine whether to perform calculation of the first gain spectrum, and meanwhile, the number of traffic channels occupied by the single-wavelength detection light in monitoring the submarine cable system can be reduced, so that the influence on the transmission efficiency of the submarine cable system in spectrum detection is reduced.

S250: a first gain spectrum is calculated based on the power variation data, the spectrum baseline, and the gain variation model.

Wherein the first gain spectrum comprises an input spectrum and an output spectrum of each optical repeater after a power change of the optical signal in the submarine cable system. It should be appreciated that the wavelength range of the optical signal in the first gain spectrum includes all of the service bands occupied by the optical signal input by the submarine cable system.

In some embodiments, the second gain spectrum in the submarine cable system may be acquired through the first detection light, so that the transmission state of the submarine cable system may be acquired through the relationship between the second gain spectrum and the spectrum baseline. Thus in some embodiments, the process of calculating the first gain spectrum from the power variation data, the spectrum baseline, and the gain variation model includes:

s251: if the second gain spectrum is not consistent with the spectrum baseline, obtaining a gain difference value between the second gain spectrum and the spectrum baseline.

After the second gain spectrum is obtained, the second gain spectrum is compared with the spectrum with the corresponding wavelength in the spectrum base line, if the second gain spectrum is consistent with the spectrum base line, the optical signal transmission in the submarine cable system is normal, no power loss or other conditions occur, if the second gain spectrum is inconsistent with the spectrum base line, the transmission abnormality occurs in the submarine cable system, the output spectrum of the submarine cable system also changes, and the input spectrum and the output spectrum of each optical repeater in the submarine cable system need to be calculated. The gain difference is a difference between the second gain spectrum and the spectrum corresponding to the first detected light wavelength in the spectrum base line, and the gain difference is obtained by calculating the difference between the second gain spectrum and the spectrum base line after the result that the second gain spectrum and the spectrum base line are not identical is obtained. When the gain difference is positive, it indicates that the gain data in the second gain spectrum is greater than the gain data in the spectrum baseline, and when the gain difference is negative, it indicates that the gain data in the second gain spectrum is less than the gain data in the spectrum baseline.

In some embodiments, the step of obtaining the gain difference comprises extracting gain spectrum information in the spectral baseline and comparing the second gain spectrum with the gain spectrum information to obtain the gain difference. Wherein the gain spectrum information includes an input spectrum and an output spectrum of the optical signal corresponding to the first detected light wavelength in the spectral baseline through each optical repeater. When the gain difference is calculated, the baselines of the input spectrum and the output spectrum corresponding to the optical signal of the first detected light wavelength can be extracted from the spectrum baselines, so that the baselines corresponding to the first detected light are obtained, and the difference is calculated according to the second gain spectrum and the gain spectrum information to obtain the gain difference. In this embodiment, the gain difference value of each optical repeater is calculated through the corresponding relation between each optical repeater and the spectrum baseline and the second gain spectrum, so as to obtain the spectrum variation data of the submarine cable system, and improve the accuracy of spectrum acquisition.

In some embodiments of the present application, the second gain spectrum comprises a second input spectrum and a second output spectrum, the gain spectrum information comprises an input gain spectrum and an output gain spectrum, and the gain difference comprises an input gain difference and an output gain difference. The second input spectrum is an input spectrum of the first detection light corresponding to each optical repeater, the second output spectrum is an output spectrum of the first detection light corresponding to each optical repeater, the input gain spectrum represents spectral information corresponding to the first detection light wavelength in the input spectrum of each optical repeater in a spectrum base line, the output gain spectrum represents spectral information corresponding to the first detection light wavelength in the output spectrum of each optical repeater in the spectrum base line, the input gain difference is a difference between the second input spectrum and the input gain spectrum, and the output gain difference is a difference between the second output spectrum and the output gain spectrum.

On the basis of dividing the gain difference by the input spectrum and the output spectrum, the step of obtaining the gain difference may further include, as shown in fig. 9:

s2511: and calculating the difference value between the second input spectrum and the input gain spectrum corresponding to each optical repeater to obtain the input gain difference value.

S2512: and calculating the difference value of the second output spectrum and the output gain spectrum corresponding to each optical repeater to obtain an output gain difference value.

The process of calculating the input gain difference is the same as the process of calculating the output gain difference, but it should be understood that in the present embodiment, the input gain difference and the output gain difference of each optical repeater need to be calculated, and even if the second gain spectrum coincides with the gain spectrum information, a gain difference having a value of 0 needs to be obtained, so that the arrangement in the subsequent step is facilitated.

S2513: and arranging the input gain difference value and the output gain difference value corresponding to each optical repeater in the receiving-transmitting sequence of each optical repeater to obtain the gain difference value.

The gain difference values are arranged according to the receiving and transmitting sequence of each optical repeater, so that the position where the fault occurs in the submarine cable system can be determined according to the position where the gain difference value is not 0.

Therefore, after the gain difference value after the arrangement is obtained, the fault location of the submarine cable system can be obtained according to the location of the gain difference value, as shown in fig. 9, which specifically includes:

S2514: each of the input gain differences and the output gain differences is detected to obtain first difference data with a first value greater than or less than a preset value.

The preset value may be 0, and a value of the input gain difference value and the output gain difference value greater than 0 or less than 0 represents that the second gain spectrum is different from the spectrum baseline. Therefore, the process of obtaining the first difference data may be to traverse each input gain difference value and each output gain difference value corresponding to each optical repeater in the submarine cable system according to the transmission sequence of the first detection light, and take the first gain difference value greater than 0 or less than 0 as the first difference data.

S2515: if the first difference data is an input gain difference, the fault area of the submarine cable system is a submarine cable connected with the input end of the first optical repeater.

The first optical repeater is an optical repeater corresponding to the first difference data. Because the optical repeaters in the submarine cable system all have an input spectrum and an output spectrum, each optical repeater respectively has a corresponding input gain difference value and an output gain difference value, and because the input gain difference value and the output gain difference value in the gain difference values are arranged according to the receiving and transmitting sequence of each optical repeater in the submarine cable system, the area with faults in the submarine cable system can be determined through the first difference value data.

For example, if the first difference data is an input gain information, it indicates that the first detection light has a power change in the submarine cable in front of the first optical repeater, so the first difference data is an input gain information, which indicates that a fault occurs in the submarine cable connected to the input end of the first optical repeater.

S2516: if the first difference data is an output gain difference, the fault area of the submarine cable system is the first optical repeater.

When the first difference data is an output gain difference, it indicates that the first detection light has power change in the amplifying process in the first optical repeater, so that the first difference data is an output gain difference, and can indicate that the fault area of the submarine cable system is the first optical repeater.

As can be seen from the foregoing embodiments, by determining whether the first gain difference is the input gain difference or the output gain difference, the location of the area where the submarine cable system fails can be determined, so that troubleshooting and maintenance can be conveniently performed.

S252: a first gain spectrum is calculated based on the gain difference and the gain variation model.

After the gain difference is obtained, the gain difference may be substituted into the gain variation model, to determine the fault type generated in the submarine cable system, and calculate the first gain spectrum corresponding to each optical repeater through the gain variation model in the above embodiment.

In some embodiments, after determining the fault area of the submarine cable system, the input spectrum and the output spectrum corresponding to each optical repeater after the fault area are acquired, so that when the first gain spectrum is calculated, the number of the input spectrum and the output spectrum which are required to be obtained is reduced, and the calculation efficiency of the spectrum is improved. Thus, as shown in fig. 9, the process of calculating the first gain spectrum includes:

s2521: a second optical repeater in the submarine cable system is determined based on the location of the first optical repeater.

Wherein the second optical repeater comprises each optical repeater connected to the output of the first optical repeater by a sea cable. After determining the position of the first optical repeater in the submarine cable system, determining each optical repeater behind the output end of the first optical repeater as a second optical repeater through the connection sequence of the optical repeaters in the submarine cable system.

It should be understood that the second optical repeater is an optical repeater connected to the output end of the first optical repeater, so if the output end of the first optical repeater is connected to a station device in the submarine cable system, the second optical repeater is not present in the submarine cable system, and only the input spectrum and the output spectrum corresponding to the first optical repeater may be calculated when the calculation of the first gain spectrum is performed.

S2522: and calculating the input spectrum and the output spectrum of each second optical repeater according to the gain difference value and the gain change model corresponding to the second optical repeater so as to obtain a first gain spectrum.

After the second optical repeaters are determined, the input gain difference value and the output gain difference value corresponding to each second optical repeater can be substituted into the gain change model, and the input spectrum and the output spectrum of each second optical repeater are calculated, so that the first gain spectrum is obtained.

It should be appreciated that in calculating the first gain spectrum, since the first optical repeater also has a power variation corresponding to the input spectrum and/or the output spectrum, the input spectrum and the output spectrum corresponding to the first optical repeater and the second optical repeater may be arranged in the order of connection, thereby obtaining the first gain spectrum.

Exemplary, after the submarine cable system operates, the optical repeater RPT in the submarine cable system is shown in FIG. 10 by transmitting a first detection light with a single wavelength to the submarine cable system and acquiring a second gain spectrum corresponding to the first detection light _m+1 The power of the received optical signal decreases and the RPT _m The transmitted optical signal is normal, and the RPT of the optical repeater can be known at the moment _m And RPT _m+1 The sea cable between the two is in the condition of increased loss, so that the input spectrum and the output spectrum of the optical repeater can be calculated by substituting the power change into the gain change model.

Specifically, the process of calculating the input spectrum and the output spectrum by the gain variation model in this embodiment includes:

the first locations to increase due to loss are the optical repeater RPT _m And RPT _m+1 Sea cable, RPT between _m Both the input spectrum and the output spectrum of (a) are coincident with the spectral baseline, so RPT _m The input spectrum and the output spectrum of (c) are kept unchanged.

Then, RPT _m+1 Is RPT _m Data of the output spectrum of the sea cable after the sea cable is worn between the output spectrum and the sea cableThe expression is as follows:

；

wherein S is _m+1-in Is RPT _m+1 Is the input spectrum of S _m-out Is RPT _m Output spectrum of S _m-Loss Is RPT _m And RPT _m+1 Loss spectrum of submarine cable between, a is RPT _m And RPT _m+1 Increased loss of submarine cable therebetween.

RPT _m+1 The slope change of the output spectrum from the nominal power deviation due to the power change of the input spectrum is expressed as follows:

；

wherein S is _m+1-out Is RPT _m+1 Output spectrum of P _m-base Is RPT _m Nominal power, k _m-base Is RPT _m Is set in the above-mentioned range of the nominal slope,is RPT _m And RPT _m+1 RPT caused by increased submarine cable loss _m+1 Slope change of output spectrum, +.>Is RPT _m And RPT _m+1 The sea cable loss spectrum slope changes caused by the increase of the sea cable loss. And so on to obtain the input and output spectra of each subsequent stage of optical repeater.

It should be understood that, in the graph shown in fig. 10, the ordinate indicates power, and the abscissa indicates the distance of the submarine cable system, that is, the power of the first detection light changes with the increase of the distance of the submarine cable system after the first detection light is transmitted, where the power rising section is the result of the first detection light passing through the optical repeater and amplifying the first detection light by the optical repeater, and the power falling section is the result of the first detection light gradually falling due to the loss of scattering, absorption, and the like of the submarine cable during the submarine cable transmission process between the two optical repeaters.

In another embodiment of the present application, when a pump failure occurs in a certain optical repeater in the submarine cable system, the determination can be made by the spectral conditions of the optical repeater in the previous stage and the optical repeater in the next stage of the pump failure. Exemplary, when the RPT _m After pump failure, as shown in FIG. 11, the gain of the optical signal from the failed optical repeater is reduced, so that the power of the output optical signal cannot reach the spectrum baseline level, and the power of the output optical signal passes through the RPT _m-1 、RPT _m And RPT _m+1 For the second gain spectrum variation of RPT _m And calculates the input spectrum and the output spectrum of each optical repeater. Note that, the abscissa of the graph in fig. 11 is the same as that in fig. 10, and a detailed description is omitted in this embodiment.

first, due to RPT _m The problem of gain failure occurs, RPT _m-1 Is not affected, so RPT _m The input spectrum remains the baseline unchanged.

Whereas RPT _m The output spectrum is subject to power variation due to self-pumping failureAnd slope changeThe equation is expressed as follows:

；

further, at this time RPT _m The output power of (a) is reduced, resulting in an RPT _m To RPT _m+1 The sea cable loss spectrum slope between the two is changed, and the formula is expressed as follows:

；

wherein S is _m-base-Loss Is RPT _m To RPT _m+1 The base loss of the submarine cable to the optical signal,for the reason RPT _m To RPT _m+1 The change of the optical spectrum slope of the loss caused by the change of the fiber-in power of the submarine cable.

Due to RPT _m+1 Is RPT _m The output spectrum of (2) is data after passing through the submarine cable between the two and being lost, and the formula is as follows:

；

whereas RPT _m+1 Since the input spectrum is subjected to the previous stage optical repeater, i.e. RPT _m Slope change due to power change caused by pump failureAnd slope variation caused by the failure of the pump of the previous stage +.>The equation is expressed as follows:

；

and so on to obtain the input and output spectra of each subsequent stage of repeater.

In the above embodiment, after the fault position of the submarine cable system is obtained, the input spectrum and the output spectrum of each optical repeater connected with the fault position subsequently can be calculated, so as to obtain the spectrum change of the submarine cable system, reduce the calculation quantity, and improve the spectrum acquisition efficiency.

In some embodiments of the present application, after the first gain spectrum is obtained, the first gain spectrum may be displayed by a display device, so that the information such as the fault location and the fault factor of the maintainer may be prompted by the display spectrum change, so as to facilitate maintenance of the submarine cable system.

By the method, after the power of the submarine cable system is changed, the input spectrum and the output spectrum of each affected optical repeater can be calculated, so that the gain spectrum corresponding to each optical repeater in the submarine cable system is obtained, and the accuracy of spectrum acquisition is improved.

Based on the above-mentioned spectrum detection method of the submarine cable system, the present application provides a spectrum detection system of a submarine cable system for performing the spectrum detection method of the submarine cable system of any one of the foregoing, where the spectrum detection system is provided in the submarine cable system, as shown in fig. 12, the submarine cable system includes a plurality of stations configured to receive and transmit optical signals, a submarine cable provided between the plurality of stations to communicate the plurality of stations, and a plurality of optical repeaters provided in the submarine cable system, respectively, to amplify the optical signals transmitted from the stations, as shown in fig. 13, where the system includes a network management device 1310 and a submarine cable monitoring device 1320, where the network management device 1310 is provided in one station and connected to the station, where the submarine cable monitoring device 1320 is connected to the submarine cable, and where the network management device 1310 is connected to the submarine cable monitoring device 1320, where:

the network management apparatus 1310 includes a data acquisition unit 1311 and a processing calculation unit 1312. Wherein the data acquisition unit 1311 is configured to acquire first spectral test data of a plurality of optical repeaters, second spectral test data of a sea cable. The processing computing unit 1312 is configured to obtain a spectral baseline corresponding to each optical repeater from each of the first spectral test data and the second spectral test data; and acquiring a gain variation model corresponding to each optical repeater according to each first spectrum test data.

While submarine cable monitoring device 1320 is configured to monitor the submarine cable system to obtain power variation data. After the submarine cable monitoring device 1320 monitors the power variation data in the submarine cable system, the data may be sent to the processing computing unit 1312, where the processing computing unit 1312 is further configured to calculate a first gain spectrum based on the power variation data, the spectrum baseline, and the gain variation model. In some embodiments, a data storage unit 1314 may be further disposed in the network management device 1310, where the data storage unit 1314 may store the obtained data after the data acquisition unit 1311 acquires the first spectrum test data and the second spectrum test data, so as to facilitate the subsequent processing and the calculation unit 1312 to call.

As can be seen from the foregoing embodiments, the submarine cable monitoring apparatus 1320 may be a COTDR device capable of transmitting single wavelength detection light, where the COTDR device is connected to the submarine cable and the network management apparatus 1310, so as to transmit first detection light into the submarine cable to monitor the transmission status of the submarine cable system, and transmit the result obtained by the monitoring to the network management apparatus 1310.

As can be seen from the foregoing embodiments, by respectively setting the network management device 1310 and the submarine cable monitoring device 1320 in the submarine cable system, the submarine cable monitoring device 1320 can monitor the submarine cable system to obtain the power variation data of the submarine cable system, and the network management device 1310 can obtain and process the first spectrum test data and the second spectrum test data to obtain the spectrum baseline of the submarine cable system and the gain variation model corresponding to the optical repeater, so that after the power variation occurs in the submarine cable system, the gain spectrum corresponding to each optical repeater is calculated, and the accuracy of the obtained gain spectrum is improved.

In some embodiments of the present application, as shown in fig. 13, the network management apparatus 1310 further includes a spectrum display unit 1313, where the spectrum display unit 1313 is configured to display the first gain spectrum. By providing the spectrum display unit 1313 in the network management device 1310, the first gain spectrum can be displayed after the first gain spectrum is calculated, so as to remind a maintainer to maintain the submarine cable system.

The above-provided detailed description is merely a few examples under the general inventive concept and does not limit the scope of the present application. Any other embodiments which are extended according to the solution of the application without inventive effort fall within the scope of protection of the application for a person skilled in the art.

Claims

1. A spectrum detection method of a submarine cable system, applied to the submarine cable system, the submarine cable system including a plurality of stations configured to receive and transmit optical signals, a submarine cable disposed between the plurality of stations to communicate the plurality of stations, and a plurality of optical repeaters disposed on the submarine cable, respectively, to amplify the optical signals transmitted by the stations, the method comprising:

acquiring first spectrum test data of a plurality of optical repeaters and second spectrum test data of the submarine cable; the first spectrum test data comprise factory spectrum test data of each optical repeater, and the second spectrum test data comprise intrinsic Raman spectrum data of the submarine cable;

Acquiring a spectrum baseline corresponding to each optical repeater according to each first spectrum test data and each second spectrum test data; the spectrum base line comprises an input spectrum and an output spectrum of each optical repeater after the submarine cable system inputs an optical signal with preset power;

acquiring a gain variation model corresponding to each optical repeater according to each first spectrum test data; the gain variation model comprises gain data of the optical repeater for optical signals with different wavelengths and/or different powers;

monitoring the submarine cable system to obtain power variation data;

calculating a first gain spectrum according to the power variation data, the spectrum baseline and the gain variation model; the first gain spectrum comprises an input spectrum and an output spectrum of each optical repeater after the power of the optical signal in the submarine cable system is changed.

2. The method for spectrum sensing of a submarine cable system according to claim 1, wherein said obtaining a spectrum baseline corresponding to each of said optical repeaters from each of said first spectrum test data and said second spectrum test data comprises:

acquiring power information corresponding to the wavelength range of the input optical signal of the submarine cable system and different wavelength signals;

According to the wavelength range and the power information, acquiring a loss spectrum of the submarine cable to the input optical signal and a gain spectrum of each optical repeater to the input optical signal;

and determining the loss spectrum and the gain spectrum corresponding to the input optical signal as the spectrum baseline.

3. The method for spectrum detection of a submarine cable system according to claim 1, wherein said obtaining a gain variation model corresponding to each of said optical repeaters from each of said first spectrum test data comprises:

gain data of optical signals with different wavelengths and/or different powers of each optical repeater are obtained according to the first spectrum test data;

and determining the gain change model corresponding to each optical repeater according to the gain data corresponding to each optical repeater.

4. The method of claim 1, wherein monitoring the submarine cable system to obtain power variation data comprises:

transmitting a first detection light with a single wavelength into the submarine cable system;

acquiring a second gain spectrum of the first detection light in the submarine cable system as the power variation data; the second gain spectrum includes an input spectrum and an output spectrum of the first detection light as it passes through each of the optical repeaters;

Said calculating a first gain spectrum from said power variation data, said spectrum baseline, and said gain variation model, comprising:

if the second gain spectrum is not consistent with the spectrum baseline, acquiring a gain difference value between the second gain spectrum and the spectrum baseline;

and calculating the first gain spectrum according to the gain difference value and the gain change model.

5. The method for spectrum sensing of a submarine cable system according to claim 4, wherein if the second gain spectrum does not match the spectrum baseline, obtaining a gain difference between the second gain spectrum and the spectrum baseline comprises:

extracting gain spectrum information in the spectrum baseline; the gain spectrum information includes an input spectrum and an output spectrum of the optical signal corresponding to the first detected light wavelength in the spectrum baseline through each of the optical repeaters;

and comparing the second gain spectrum with the gain spectrum information to obtain the gain difference value.

6. The method of spectral detection of a submarine cable system according to claim 5, wherein the second gain spectrum comprises a second input spectrum and a second output spectrum, the gain spectrum information comprises an input gain spectrum and an output gain spectrum, the gain difference comprises an input gain difference and an output gain difference, and the comparing the second gain spectrum with the gain spectrum information to obtain the gain difference comprises:

Calculating a difference value between the second input spectrum and the input gain spectrum corresponding to each optical repeater to obtain an input gain difference value;

calculating the difference value between the second output spectrum and the output gain spectrum corresponding to each optical repeater to obtain an output gain difference value;

and arranging the input gain difference value and the output gain difference value corresponding to each optical repeater in the receiving-transmitting sequence of each optical repeater to obtain the gain difference value.

7. The method of spectral detection of a submarine cable system according to claim 6, wherein after said comparing said second gain spectrum with said gain spectrum information to obtain a gain difference, said method further comprises:

detecting each of the input gain difference and the output gain difference in the gain differences to obtain first difference data larger than a preset value or smaller than the preset value;

if the first difference value data is one input gain difference value, the fault area of the submarine cable system is the submarine cable connected with the input end of the first optical repeater; the first optical repeater is the optical repeater corresponding to the first difference data;

And if the first difference value data is one output gain difference value, the fault area of the submarine cable system is the first optical repeater.

8. The method of spectral detection of a submarine cable system according to claim 7, wherein said calculating said first gain spectrum from said gain difference and said gain variation model comprises:

determining a second optical repeater in the submarine cable system according to the position of the first optical repeater; the second optical repeater comprises each optical repeater connected with the output end of the first optical repeater through the submarine cable;

and calculating an input spectrum and an output spectrum of each second optical repeater according to the gain difference value and the gain change model corresponding to the second optical repeater so as to obtain the first gain spectrum.

9. The method of spectral detection of a submarine cable system according to claim 1, wherein after said calculating a first gain spectrum, said method further comprises: the first gain spectrum is displayed.

10. A spectrum detection system for a submarine cable system for performing the spectrum detection method of a submarine cable system according to any one of claims 1 to 9, the spectrum detection system being provided in a submarine cable system comprising a plurality of stations configured to receive and transmit optical signals, a submarine cable provided between the plurality of stations to communicate the plurality of stations, and a plurality of optical repeaters provided on the submarine cable respectively to amplify the optical signals transmitted from the stations, characterized in that the system comprises a network management device provided in one of the stations and connected to the stations, and a submarine cable monitoring device connected to the submarine cable, the network management device being connected to the submarine cable monitoring device, wherein:

The network management apparatus includes:

a data acquisition unit configured to: acquiring first spectrum test data of a plurality of optical repeaters and second spectrum test data of the submarine cable;

a processing calculation unit configured to: acquiring a spectrum baseline corresponding to each optical repeater according to each first spectrum test data and each second spectrum test data;

acquiring a gain variation model corresponding to each optical repeater according to each first spectrum test data;

the submarine cable monitoring device is configured to: monitoring the submarine cable system to obtain power variation data;

the processing computing unit is further configured to: and calculating a first gain spectrum according to the power change data, the spectrum baseline and the gain change model.

11. The submarine cable system spectrum detection system according to claim 10, wherein the network management device further comprises a spectrum display unit configured to display the first gain spectrum.