Operation and maintenance monitoring method and apparatus for multi-band optical communication system

Abstract

The present application belongs to the field of optical communications. Disclosed are an operation and maintenance monitoring method and apparatus for a multi-band optical communication system. The method comprises: constructing a wave channel loss difference table, which comprises a standard value of an optical power loss difference for another target waveband when an optical path failure occurs in any target waveband; acquiring real-time values of optical power loss differences for two target wavebands; and when the real-time value for one target waveband is greater than a corresponding standard value, determining that an optical path failure occurs in the other target waveband. In the present application, the transient characteristics of a local optical power change are used to promptly and accurately obtain failure information of an adjacent waveband, thereby avoiding the drawbacks of relaying the failure information by means of third-party software and addressing the challenge of failure information exchange between different target wavebands in a multi-band optical communication system, such that simultaneous dual-end switching of two target wavebands when an optical path failure occurs in any target waveband is realized, thus improving the timeliness and security of system switching and ensuring the safety of maintenance personnel.

Description

A method and device for operation and maintenance monitoring of a multi-band optical communication system Technical Field

[0001] This application relates to the field of optical communication, specifically to a method and apparatus for operation and maintenance monitoring of a multi-band optical communication system. Background Technology

[0002] In wavelength division multiplexing (WDM) optical communication systems, the service information to be transmitted is modulated onto different optical frequencies, i.e., different wavelength channels (or channels) for transmission. With the increase in traffic, it is necessary to expand and utilize more fiber optic spectrum resources beyond the traditional C-band. L-band-based capacity expansion is currently the most common method for capacity expansion.

[0003] In multi-band optical communication systems using the C+L configuration for full-wavelength, high-capacity transmission, the input light from the C-band and L-band bands, after being combined and transmitted through the optical fiber, is affected by Raman gain. As shown in Figure 1, the horizontal axis represents frequency, and the vertical axis represents Raman gain. As long as the wavelength difference between different channels in the optical signal is within the Raman gain range, stimulated Raman scattering (SRS) will transfer energy from the short channel to the long channel, resulting in a nonlinear effect of amplifying the long channel with the short channel, thereby reducing system performance. Figure 2 shows a schematic diagram of a split C+L optical communication system. C-band incident light enters from the upstream C-band point S1, and L-band incident light enters from the upstream L-band point S2. A multiplexer is located near the upstream side of the C+L band point S3, and a demultiplexer is located near the downstream side. The multiplexer near the upstream side combines the C-band and L-band incident light and sends it to the C+L band point S3. The light is then transmitted via optical fiber from the C+L band point S3 to the demultiplexer near the downstream side. The demultiplexer receives the light... The received light is split into C-band incident light and L-band incident light. The C-band incident light is processed by the downstream C-band S4 point and output as C-band output light. The L-band incident light is processed by the downstream L-band S5 point and output as L-band output light. When the C-band incident light and L-band incident light are combined by the multiplexer and sent into the optical fiber at point S3 for multiplexing and transmission, there will be a certain optical power loss, resulting in an optical power difference between the incident light and the split light.

[0004] Based on the different transmission product architectures, common multi-band optical communication systems are divided into two categories: integrated C+L systems and discrete C+L systems.

[0005] In an integrated C+L system, the C-band and L-band are based on a common optical platform for optical signal transmission and monitoring. When a fiber break or severe wave drop occurs in either band, the other band can be notified in time and take protective measures (such as shutting down the laser or amplifier and performing protection switching).

[0006] In a split C+L system, the C-band and L-band rely on different optical platforms for optical signal transmission and monitoring. The optical communication management modes of these platforms differ, making coordinated management of the various devices in both bands challenging during maintenance. Furthermore, due to the heterogeneity of the C-band and L-band (C-band using a 1510nm Optical Supervisory Channel (OSC) and L-band using a 1625nm OSC), and the proprietary monitoring protocols of these different vendors' OSC channels, direct interoperability is impossible. A third-party controller is required for relaying the communication. Consequently, if an optical path failure occurs in either band, the other band is unlikely to be detected promptly, hindering timely protective measures and negatively impacting system performance and operational security. Summary of the Invention

[0007] This application provides a method and apparatus for operation and maintenance monitoring of multi-band optical communication systems, especially split C+L optical communication systems, which can solve the technical problem in the prior art that optical path faults cannot be detected in a timely manner between different bands.

[0008] In a first aspect, embodiments of this application provide an operation and maintenance monitoring method for a multi-band optical communication system, the system comprising two target bands configured at full wavelength; the method includes:

[0009] A channel loss difference table is constructed, which includes the standard value of the optical power loss difference of another target band when an optical path failure occurs in any target band; the optical power loss difference is the change in optical power difference of the target band before and after multiplexing transmission.

[0010] Obtain the real-time value of the optical power loss difference between the two target bands;

[0011] When the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path failure has occurred in another target band.

[0012] In conjunction with the first aspect, in one embodiment, obtaining the real-time value of the optical power loss difference between the two target bands specifically includes the following steps:

[0013] Input power is collected at the output side of the multiplexer in a multi-band optical communication system, and output power is collected at the output side of the demultiplexer.

[0014] Optical power loss is obtained from the difference between output power and input power;

[0015] The optical power loss difference is obtained by measuring the difference between two consecutive optical power losses.

[0016] In conjunction with the first aspect, in one implementation, the two target bands are C-band and L-band; the construction of the channel loss difference table specifically includes the following steps:

[0017] Multiple channels in the C-band full-channel array are selected as C sampling channels, and a standard value for the difference in optical power loss of each C sampling channel is set when an optical path failure occurs in the L-band.

[0018] Multiple channels in the full-wavelength L-band are selected as L-sampling channels, and a standard value for the difference in optical power loss of each L-sampling channel is set when an optical path failure occurs in the C-band.

[0019] The channel loss difference table is constructed based on the standard values ​​of all the C-sampled channels and L-sampled channels.

[0020] In conjunction with the first aspect, in one implementation, one channel is selected from every four channels in the C-band full channel in order of wavelength from longest to shortest as the C sampling channel, and a standard value for the difference in optical power loss of each C sampling channel is set when an optical path failure occurs in the L-band.

[0021] Following the order of wavelength from longest to shortest, one channel out of every four channels in the full-channel L-band is selected as the L sampling channel, and a standard value for the difference in optical power loss of each L sampling channel is set when an optical path failure occurs in the C-band.

[0022] In conjunction with the first aspect, in one implementation, before determining whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value, the method further includes:

[0023] Multiple channels from all C sampling channels are selected as C monitoring channels; when the real-time values ​​of all C monitoring channels are greater than the preset trigger value of the optical power loss difference, the triggering stage is entered to determine the optical path fault in the L band.

[0024] In conjunction with the first aspect, in one implementation, before determining whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value, the method further includes:

[0025] Multiple channels from all L sampling channels are selected as L monitoring channels; when the real-time values ​​of all L monitoring channels are greater than the preset trigger value of the optical power loss difference, the triggering stage is entered to determine the optical path fault in the C band.

[0026] In conjunction with the first aspect, in one implementation, the step of determining whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value specifically includes the following steps:

[0027] When the real-time value of a target band is greater than the corresponding standard value, a monitoring message is obtained from the optical monitoring channel of the target band, and the target band itself is judged based on the message to determine whether there is an optical path failure. If so, the judgment is terminated; otherwise, it is determined that there is an optical path failure in another target band.

[0028] In conjunction with the first aspect, in one implementation, determining whether a real-time value of a target band is greater than a corresponding standard value specifically includes the following steps:

[0029] The channel with the longest wavelength in the C sampling channels is designated as the first C calibration channel, and the channel with the shortest wavelength is designated as the second C calibration channel.

[0030] When it is determined that the real-time value of the second C calibration channel is greater than the corresponding standard value and the real-time value of the first C calibration channel is greater than the real-time value of the second C calibration channel, it is determined that the real-time value of the C band is greater than the corresponding standard value.

[0031] In conjunction with the first aspect, in one implementation, determining whether a real-time value of a target band is greater than a corresponding standard value specifically includes the following steps:

[0032] The channel with the longest wavelength in the L sampling channels is designated as the first L calibration channel, and the channel with the shortest wavelength is designated as the second L calibration channel.

[0033] When it is determined that the real-time value of the second L calibration channel is greater than the corresponding standard value and the real-time value of the first L calibration channel is greater than the real-time value of the second L calibration channel, it is determined that the real-time value of the L band is greater than the corresponding standard value.

[0034] Secondly, embodiments of this application provide an operation and maintenance monitoring device for a multi-band optical communication system, the device comprising:

[0035] The preprocessing module is used to construct a channel loss difference table, which includes a standard value of the optical power loss difference of another target band when an optical path failure occurs in any target band; the optical power loss difference is the change in optical power difference of the target band before and after multiplexing transmission.

[0036] The monitoring module is used to obtain the real-time value of the difference in optical power loss between the two target bands; when the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path fault has occurred in the other target band.

[0037] The beneficial effects of the technical solutions provided in this application include:

[0038] Compared to traditional solutions that are limited to detecting optical path fault events within their own band (e.g., detecting changes in optical power loss downstream of the C-band to obtain fault information upstream of the C-band), this invention transcends the C-band scope. It can obtain C-band fault information by detecting changes in optical power downstream of the L-band; similarly, it can obtain L-band fault information by detecting changes in optical power downstream of the C-band. This invention utilizes the instantaneous nature of optical power changes to promptly and accurately obtain fault information from adjacent bands, avoiding the drawbacks of relaying fault information through third-party software. It solves the problem of intercommunication between C-band and L-band fault information in a split C+L system, thus enabling simultaneous bi-directional switching of both bands in the event of a C+L fault. In other words, when only one band (C-band or L-band) fails, both L-band and C-band switch simultaneously. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the Raman effect in the prior art;

[0040] Figure 2 is a schematic diagram of the architecture of a split C+L optical communication system;

[0041] Figure 3 is a flowchart illustrating the first embodiment of the operation and maintenance monitoring method for the multi-band optical communication system of this application.

[0042] Figure 4 is a detailed flowchart of step S2 in Figure 3 of this application;

[0043] Figure 5 is a detailed flowchart of step S1 in Figure 3 of this application;

[0044] Figure 6 is one of the detailed flowcharts of step S3 in Figure 3 of this application;

[0045] Figure 7 is a second detailed flowchart of step S3 in Figure 3 of this application;

[0046] Figure 8 shows the real-time value fitting curve of the optical power loss difference of the C sampling channel;

[0047] Figure 9 shows the real-time value fitting curve of the optical power loss difference of the L sampling channel;

[0048] Figure 10 is a functional module schematic diagram of an embodiment of the operation and maintenance monitoring device for the multi-band optical communication system of this application. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0050] First, some of the technical terms used in this application will be explained to help those skilled in the art understand this application.

[0051] Target band: The pre-set service band.

[0052] Full Waveform State: The power of all designated wavelength channels in the target band (these wavelength channels are used to carry service information) is greater than the preset power threshold. That is, all wavelength channels have waves, i.e., there are optical signals. These optical signals can be optical signals carrying service information or optical signals not carrying service information.

[0053] Stimulated Raman effect: After optical signals are transmitted through optical fibers, the energy of short-wavelength optical signals will be transferred to long-wavelength optical signals, resulting in a spectral distribution with a certain tilt, where the optical power of short-wavelength optical signals is low and the optical power of long-wavelength optical signals is high.

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0055] In a first aspect, embodiments of this application provide an operation and maintenance monitoring method for a multi-band optical communication system.

[0056] In one embodiment, referring to Figure 3, which is a flowchart illustrating the first embodiment of the operation and maintenance monitoring method for a multi-band optical communication system according to this application, the operation and maintenance monitoring method for a multi-band optical communication system includes:

[0057] Step S1: Construct a channel loss difference table, which includes the standard value of the optical power loss difference of one target band when an optical path failure occurs in any target band. The above optical power loss difference is the change in the optical power difference of the target band before and after multiplexing transmission.

[0058] Step S2: Obtain the real-time value of the difference in optical power loss between the two target bands.

[0059] Step S3: When the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path fault has occurred in another target band.

[0060] In this embodiment, for a bidirectional transmission system, the present invention focuses on the scenario where power transfer caused by the Raman effect has occurred after two target bands are transmitted together. By real-time detection of the changes in optical power upstream and downstream of the two target bands, the degree of change in line loss is determined and whether it matches the power transfer characteristics of the system. If it matches, it can be further determined that a serious fault has occurred in the other upstream band (such as fiber optic interruption or amplifier failure), and then protective measures can be taken in this band.

[0061] Conventional detection algorithms can be used to monitor the optical power of each target band in real time, storing the transmitting power of upstream sites and the receiving power of downstream sites. The difference between transmitting and receiving power is called power transfer. Since wavelength-dependent loss (also known as line loss) equals transmitting power minus receiving power, and wavelength-dependent loss also equals fiber loss plus power transfer, under the premise that a multi-channel optical communication system is a full-wavelength system, fiber loss is fixed, and power transfer is also fixed under normal conditions. Only under abnormal conditions, such as fiber breakage or severe dropout in an adjacent band, will there be a sudden change in downstream power transfer in this band. Utilizing the Raman effect power transfer characteristics, by detecting the change in line loss of one band at different times, the occurrence of upstream abnormal events in another band can be identified. Specifically, an optical power meter (OPM) can be used for data acquisition.

[0062] Compared to traditional solutions that are limited to detecting optical path fault events within their own band (e.g., detecting changes in optical power loss downstream of the L-band to obtain fault information upstream of the C-band), this invention transcends the C-band scope. It can obtain C-band fault information by detecting changes in optical power downstream of the L-band. Similarly, it can obtain L-band fault information by detecting changes in optical power downstream of the C-band. This invention utilizes the instantaneous nature of optical power changes to promptly and accurately obtain fault information from adjacent bands, avoiding the drawbacks of relaying fault information through third-party software. It solves the problem of intercommunication between C-band and L-band fault information in a split C+L system, thus enabling simultaneous bi-directional switching of both bands in the event of a C+L fault; that is, when only one band (C-band or L-band) fails, both L-band and C-band switch simultaneously.

[0063] Furthermore, in one embodiment, referring to Figure 4, obtaining the real-time value of the optical power loss difference between the two target bands specifically includes the following steps:

[0064] Step S21a: Acquire the input power at the output side of the multiplexer in the multi-band optical communication system and the output power at the output side of the demultiplexer.

[0065] Step S22a: Obtain the optical power loss based on the difference between the output power and the input power.

[0066] Step S23a: Obtain the optical power loss difference based on the difference between two adjacent optical power losses.

[0067] In this embodiment, a split C+L optical communication system is used as an example of a multi-band optical communication system. Other multi-band optical communication systems, such as S+U band optical communication systems, can be regarded as extensions of the present invention, and their fault monitoring schemes are the same as those of the present invention.

[0068] Referring to Figure 2, which is a schematic diagram of the architecture of a split C+L optical communication system, the power of the L-band incident light before it enters the multiplexer at point S3 in the C+L band is collected as the input power of the L-band. The power of the L-band split light transmitted from the demultiplexer to point S5 in the downstream L-band is collected as the output power. The difference between the input power and the output power is the optical power loss of the L-band. The difference between the optical power loss calculated from two adjacent collections is the optical power loss difference. Under the premise that the fiber loss remains basically constant, if the optical power loss difference of one band is greater than a preset threshold, it indicates that there is an optical path fault upstream of another band. After timely detection of faults in other bands, this band can be promptly protected and switched over. Using optical power fluctuations to realize fault detection in adjacent bands, its reliability and timeliness can meet the high reliability and near-stringent timeliness requirements of telecommunications.

[0069] Furthermore, considering that when maintenance personnel are inspecting other faulty bands, if the fault in other bands is not detected in time, there will still be optical signals on the output side of the multiplexer, which may cause harm to the eyes of the maintenance personnel. Therefore, this invention can promptly shut down the laser in this band or reduce the pump power to a safe value after timely detection of faults in other bands. This enables the timely shutdown of the optical power of the amplifier in another band when a single amplifier in any band is turned off, thereby optimizing the existing automatic power reduction (APR) eye protection strategy for C+L multiplexing channels.

[0070] Furthermore, in one embodiment, referring to Figure 5, the two target bands are the C-band and the L-band. The construction of the channel loss difference table specifically includes the following steps:

[0071] Step S11a: In order of wavelength from longest to shortest, select one channel from every four channels in the C-band full channel as the C sampling channel, and set a standard value for the difference in optical power loss of each C sampling channel when an optical path failure occurs in the L-band.

[0072] Step S12a: In order of wavelength from longest to shortest, take one channel out of every four channels in the full channel of the L band as the L sampling channel, and set the standard value of the optical power loss difference of each L sampling channel when an optical path failure occurs in the C band.

[0073] Step S13a: Construct the channel loss difference table based on the standard values ​​of all the above-mentioned C sampling channels and L sampling channels.

[0074] Steps S11a and S12a can be performed simultaneously.

[0075] In this embodiment, due to different C+L application strategies, specifically, in scenario one: the C-band system is initially activated, and then the L-band is expanded later, sufficient margin must be reserved for the C-band amplifier before expansion. In scenario two: the L-band system is initially activated, and then the C-band is expanded later, requiring a gradual reduction in L-band optical power during C-band expansion. Both of these methods are detrimental to adjusting system flatness. Therefore, in practical engineering applications, it is recommended that the C+L system adopt scenario three when it is initially activated: both C-band and L-band are configured at full wavelength, for example, C96 and L96 are activated together, C48 and L48 are activated together. The system is configured at full wavelength from the initial stage, and during later service activation, a corresponding filler channel is closed / opened for each added / removed service channel to avoid significant changes in system power. This invention, based on this scenario, primarily considers the full-wave configuration of each channel.

[0076] Common full-wavelength systems are 40, 80, 96, or 120 channels. A certain number of sampling channels need to be selected to achieve channel sampling detection based on the SRS effect. The selection of sampling channels considers two factors: software construction and channel anomalies. In the current network environment, a single channel may experience optical power anomalies due to service switching, but the probability of more than three channels experiencing anomalies simultaneously is less than the boundary of a normal distribution. Therefore, the number of sampling channels cannot be small. This invention selects one-quarter of the total number of full-wavelength channels, which is divisible by common full-wavelength systems. For example, in a C-band 96-channel system, channels 1 through 24 are sequentially arranged from channel 1 to channel 5, and the channel loss of channels 1 through n (n=24) is recorded. The processing for the L-band is similar.

[0077] Furthermore, in one embodiment, when monitoring whether an optical path fault has occurred in the L-band, before determining whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value, multiple of all C sampling channels are taken as C monitoring channels. When it is determined that the real-time values ​​of all C monitoring channels are greater than the preset trigger value of the optical power loss difference, the triggering stage is entered to determine the optical path fault in the L-band.

[0078] When monitoring for optical path faults in the C-band, before determining whether an optical path fault has occurred in another target band based on the real-time value and corresponding standard value of one target band, multiple L sampling channels are selected as L monitoring channels. When it is determined that the real-time values ​​of all L monitoring channels are greater than the preset trigger value for optical power loss difference, the triggering phase is initiated to determine optical path faults in the C-band.

[0079] In this embodiment, within one cycle t, line loss anomalies of a single C sampling channel are not counted in the event record. Anomalies of a single C sampling channel can be compared with those of other C sampling channels. The purpose is to filter out jitter events of individual channels. Only when the line loss of n1 to nr C monitoring channels of 1 to n C sampling bands is greater than the trigger monitoring threshold a, i.e., the aforementioned trigger value, is the current time recorded as the trigger time. After the trigger time, the triggering phase begins. During the triggering phase, the real-time value of the C sampling channel is collected. When the real-time value is greater than the standard value, it is determined that an optical path fault has occurred in the L band.

[0080] Similarly, within a cycle t, line loss anomalies of a single L sampling channel are not counted in the event record. Anomalies of a single L sampling channel can be compared with those of other L sampling channels. The purpose is to filter out jitter events of individual channels. Only when the line loss of nL to nL monitoring channels of 1 to n L sampling bands is greater than the trigger monitoring threshold d, i.e., the trigger value mentioned above, is the current time recorded as the trigger time. After the trigger time, the triggering phase begins. During the triggering phase, the real-time value of the L sampling channel is collected. When the real-time value is greater than the standard value, it is determined that an optical path fault has occurred in the C band.

[0081] By selecting several monitoring channels from the sampling channels, and entering the triggering phase for optical path fault judgment when the real-time value of the optical power loss difference in all monitoring channels is greater than the corresponding trigger value, the accuracy of the judgment results can be improved, and interference from small fluctuations can be avoided. For example, in an L-band with 96 channels, two channels—channel 20 (l20) and channel 60 (l60)—experience a momentary fluctuation of 3 dB, while other channels remain unchanged. This is a small fluctuation, not a fluctuation caused by an optical path fault in the C-band. If the triggering time is not determined, and the optical path fault monitoring software happens to use channels l20 and l60 in the L-band for fault judgment, it is easy to misjudge an optical path fault in the C-band. Therefore, by adding the determination of the triggering time, only when the optical power loss fluctuation of a certain number of channels reaches the trigger value can the optical path fault in another band be judged based on the optical power loss fluctuation of a small number of channels after entering the triggering phase, thus improving the accuracy of fault monitoring and reducing the required computation.

[0082] Furthermore, in one embodiment, the above-mentioned determination of whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value specifically includes the following steps:

[0083] When the real-time value of a target band exceeds the corresponding standard value, a monitoring message is obtained from the optical monitoring channel of that target band. Based on the message, it is determined whether there is an optical path fault in the target band itself. If so, the current judgment is terminated. If not, it is determined that there is an optical path fault in another target band.

[0084] In this embodiment, due to inherent full-wavelength fluctuations in the C-band or L-band, when determining that the real-time value of a target band exceeds the corresponding standard value, it is necessary to eliminate interference from damage to the optical amplifier and fiber within that band. Specifically, after the trigger moment, the C-band status byte in the OSC message is compared to eliminate the possibility of optical channel failure. Similarly, the L-band status byte in the OSC message is compared to eliminate the possibility of optical channel failure.

[0085] Furthermore, in one embodiment, referring to Figure 6, when monitoring whether an optical path fault has occurred in the L-band, the above-mentioned determination of whether the real-time value of a target band is greater than the corresponding standard value specifically includes the following steps:

[0086] Step S31a: Select the channel with the largest wavelength in the C sampling channels as the first C calibration channel and the channel with the smallest wavelength as the second C calibration channel.

[0087] Step S32a: When it is determined that the real-time value of the second C calibration channel is greater than the corresponding standard value and the real-time value of the first C calibration channel is greater than the real-time value of the second C calibration channel, it is determined that the real-time value of the C band is greater than the corresponding standard value.

[0088] Referring to Figure 7, when monitoring whether an optical path fault has occurred in the C-band, the above-mentioned determination of whether the real-time value of a target band is greater than the corresponding standard value specifically includes the following steps:

[0089] Step S31b: Select the channel with the largest wavelength in the L sampling channels as the first L calibration channel and the channel with the smallest wavelength as the second L calibration channel.

[0090] Step S32 b: When it is determined that the real-time value of the second L calibration channel is greater than the corresponding standard value and the real-time value of the first L calibration channel is greater than the real-time value of the second L calibration channel, it is determined that the real-time value of the L band is greater than the corresponding standard value.

[0091] In this embodiment, utilizing the SRS effect characteristics of full-wave power transfer in a C+L system, a pre-defined empirical database, namely a channel loss difference table, is constructed. For common C+L amplifier configurations in engineering, the empirical database is summarized to form a series of combined values, including a trigger value of 'a' for the C-band optical power loss difference, 'd' for the L-band optical power loss difference, a standard value of b4 for the optical power loss difference of the first C-calibrated channel, a standard value of b3 for the optical power loss difference of the second C-calibrated channel, a standard value of b1 for the optical power loss difference of the first L-calibrated channel, and a standard value of b2 for the optical power loss difference of the second L-calibrated channel. The fault monitoring method of this invention, based on pre-set numerical combinations, can quickly achieve the purpose of fault event monitoring.

[0092] Specifically, when constructing the channel loss difference table, the first quarter of the full C-band channel is selected as the C sampling channel, and a standard value for the optical power loss difference of each C sampling channel is set when an optical path failure occurs in the L-band. Similarly, the last quarter of the full L-band channel is selected as the L sampling channel, and a standard value for the optical power loss difference of each L sampling channel is set when an optical path failure occurs in the C-band.

[0093] Real-time values ​​of optical power loss difference in the C sampling channel and the L sampling channel are collected. The first nc channels in the C sampling channel are used as the C monitoring channels, and the last nl channels in the L sampling channel are used as the L monitoring channels. nc can be selected as half of the C sampling channels, and nl can be selected as half of the L sampling channels.

[0094] When the real-time values ​​of the first nc C monitoring channels are all greater than the trigger value a, the triggering phase is initiated to determine optical path faults in the L band. When the real-time values ​​of the last nl L monitoring channels are all greater than the trigger value d, the triggering phase is initiated to determine optical path faults in the C band.

[0095] When entering the trigger phase to determine optical path faults in the L-band, it is necessary to first rule out real-time value fluctuations caused by full-wavelength anomalies in the C-band (such as interference factors like damage to the optical amplifier and fiber). Specifically, this is done by comparing the C-band status bytes in the OSC messages collected by the C-band OSC to rule out internal optical path faults. Similarly, this is done by comparing the L-band status bytes in the OSC messages collected by the L-band OSC to rule out internal optical path faults.

[0096] After excluding real-time value fluctuations caused by its own factors, the real-time value of the C-sampling channel is compared with the standard value. If the real-time value reaches the standard value, it is determined that an optical path fault has occurred in the L-band. When comparing the real-time value of the C-sampling channel with the standard value, the real-time value of all C-sampling channels can be compared with the corresponding standard value. If all of them reach the standard value, it is determined that an optical path fault has occurred in the L-band, but this involves a large amount of calculation.

[0097] Referring to Figure 8, the horizontal axis represents the wavelength of the C-sampling channel, and the vertical axis represents the line loss difference of the C-sampling channel (corresponding to the real-time value of the optical power loss difference). The wavelength of the C target band ranges from 1530nm to 1565nm. Generally, as the wavelength of each channel in the C-sampling band increases, the real-time value of the C-sampling channel gradually decreases. Therefore, when the real-time value of the C-sampling channel with the smallest wavelength is greater than the corresponding standard value, it can be assumed that the real-time values ​​of other C-sampling channels are greater than the corresponding standard values. Thus, by selecting the minimum number, i.e., at least two C-sampling channels, taking the channel with the largest wavelength as the first C-calibration channel and the channel with the smallest wavelength as the second C-calibration channel, when the real-time value of the second C-calibration channel is less than the real-time value of the first C-calibration channel, it is determined that the real-time value of the C-sampling channel shows a gradually decreasing trend. When the real-time value of the second C-calibration channel is greater than the corresponding standard value, it is determined that the real-time values ​​of all C-sampling channels are greater than the corresponding standard values, and further, it is determined that an optical path fault has occurred in the L-band. Compared to collecting real-time values ​​from all C-sampled channels and comparing them with corresponding standard values, this method requires less computation and is more efficient.

[0098] Referring to Figure 9, the horizontal axis represents the wavelength of the L-sampling channel, and the vertical axis represents the line loss difference of the L-sampling channel (corresponding to the real-time value of the optical power loss difference). The wavelength of the L target band ranges from 1565nm to 1625nm. Generally, as the wavelength of each channel in the L-sampling band increases, the real-time value of the L-sampling channel gradually decreases. Therefore, when the real-time value of the L-sampling channel with the largest wavelength is greater than the corresponding standard value, it can be assumed that the real-time values ​​of other L-sampling channels are greater than the corresponding standard values. Thus, by selecting the minimum number, i.e., at least two L-sampling channels, taking the channel with the largest wavelength as the first L-calibration channel and the channel with the smallest wavelength as the second L-calibration channel, when the real-time value of the first L-calibration channel is greater than the real-time value of the second L-calibration channel, it is determined that the real-time value of the L-sampling channel shows a gradually decreasing trend. When the real-time value of the second L-calibration channel is greater than the corresponding standard value, it is determined that the real-time values ​​of all L-sampling channels are greater than the corresponding standard values, and it is further determined that an optical path fault has occurred in the C-band. Compared to collecting real-time values ​​from all L-sampling channels and comparing them with corresponding standard values, this method requires less computation and is more efficient.

[0099] Since the shortest wavelength channel transfers a portion of its energy to all channels within the Raman gain bandwidth, this channel is most affected by Raman induced crosstalk. Therefore, the approach of segmenting and taking the minimum real-time value of the affected channel in this invention is feasible. By segmenting and comparing the minimum real-time value and the trend of this change, it can be determined that this change is consistent with the SRS power characteristics of a multi-band system.

[0100] In a specific embodiment, the specific process of the operation and maintenance monitoring method for a multi-band optical communication system is as follows:

[0101] First, as shown in Figure 7, the sampling channels are set. Taking both the C-band and L-band as having 96 channels as an example, one-quarter of the target C-band is selected as the C sampling channels (the number of C sampling channels is n), and one-quarter of the target L-band is selected as the L sampling channels (the number of L sampling channels is n). The optical power loss of the n C sampling channels and the optical power loss of the n L sampling channels are recorded at time t1.

[0102] Secondly, the trigger monitoring processes for C-band and L-band are as follows: half of the C sampling channels are selected as C monitoring channels (the number of C monitoring channels is n / 2), and half of the L sampling channels are selected as L monitoring channels (the number of L monitoring channels is n / 2).

[0103] Record the optical power loss of n / 2 C monitoring channels and n / 2 L monitoring channels at time t2. The difference between the optical power loss of the C monitoring channels at time t2 and time t1 is the real-time value of the optical power loss difference detected in the C band, i.e., C1 to C12. When C1 to C12 are all greater than the preset trigger value 'a' for the optical power loss difference in the C band, the C band triggering stage is entered. The trigger value 'a' must be less than the median of the standard values ​​of all C sampling channels. The difference between the optical power loss of the L monitoring channels at time t2 and time t1 is the real-time value of the optical power loss difference detected in the L band, i.e., C1 to C12. When L1 to L12 are all greater than the preset trigger value 'd' for the optical power loss difference in the L band, the L band triggering stage is entered. The trigger value 'd' must be less than the median of the standard values ​​of all L sampling channels.

[0104] Secondly, in actual fiber optic lines, damage to optical amplifiers or optical fibers can lead to changes in line loss. The C-band and L-band sampling channels themselves may also have inherent faults, requiring further troubleshooting using the Optical Monitoring Channel (OSC) equipment. Specifically, after the sampling band triggers, the C-band status byte in the C-band OSC message is checked. If the OSC status byte indicates a fault in the C-band itself, the process returns to the initial steps; otherwise, fault diagnosis continues. The L-band process is similar: the L-band status byte in the L-band OSC message is checked. If the OSC status byte indicates a fault in the L-band itself, the process returns to the initial steps; otherwise, fault diagnosis continues.

[0105] Finally, after fixing the input fiber power in the C-band, the line loss slopes are basically consistent and linear. The C-band sampling channel can be divided into two parts: n1 to nc is the first half, and nc-n is the second half. In this example, nc can be half of n, i.e., waves 1 to 12 are the first half, and waves 13 to 24 are the second half. b3 is the line loss characteristic value, i.e., the standard value, for the second half of the C-band sampling channel. The line loss variation values, i.e., the real-time values, from wave 24 to wave 13 are recorded sequentially. If all are greater than b3, then the second half of the C-band sampling channel conforms to the power transfer loss characteristics. b4 is the line loss characteristic value for the first half of the C-band sampling channel. The line loss variation values, from wave 12 to wave 1, are recorded sequentially. If all are greater than b4, then the first half of the C-band sampling channel conforms to the power transfer loss characteristics. Provided that both the preceding and following C-band sampling channels simultaneously meet the power transfer loss characteristics, the line loss difference between the tail, middle, and head channels of the C-band sampling channel is compared. If the loss difference between the 24th, 12th, and 1st channels increases sequentially, it can be determined that the channel loss in the C-band is caused by the power characteristic transfer in the L-band. Therefore, it can be determined that an abnormal fault event has occurred in the L-band. An abnormal fault alarm in the L-band is reported in the C-band OSC message, and further measures are taken.

[0106] After fixing the input fiber power in the L-band, the line loss slope exhibits a certain curvature. Similarly, the L-band can be divided into two parts: n1 to nl is the first half, and nl-n is the second half. In this example, nl can be half of n, i.e., waves 1 to 12 are the first half, and waves 13 to 24 are the second half. b1 is the line loss characteristic value of the first half of the L-band sampling channel. The line loss variation values ​​of waves 1 to 12 are recorded sequentially. If all are greater than b1, then the first half of the L-band sampling channel conforms to the power transfer loss characteristic. b2 is the line loss characteristic value of the second half of the L-band sampling channel. The line loss variation values ​​of waves 13 to 24 are recorded sequentially. If all are greater than b2, then the second half of the L-band sampling channel conforms to the power transfer loss characteristic. Under the premise that the front and rear sampling channels simultaneously meet the power transfer loss characteristics, the line loss difference between the tail, middle and head channels of the L sampling channel is compared. If the loss difference of wave 1, wave 12 and wave 24 increases sequentially, it can be determined that the channel loss in the L band is caused by the power characteristic transfer of the C band. Then, it can be determined that an abnormal fault event has occurred in the C band. The abnormal fault alarm of the C band is reported in the L band OSC message, and further measures are taken.

[0107] In a split C+L optical communication system, the measures taken when an optical path failure occurs include, but are not limited to, activating optical line protection, switching optical channel protection panels, shutting down optical amplifiers or lasers, etc., and these measures can be regarded as a continuation of the present invention.

[0108] When both C-band and L-band are combined at 21 dBm, the minimum standard value for the channel loss difference at the first wavelength of the L-band is 0.3 dB, and the minimum standard value for the channel loss difference at the last wavelength of the C-band is 0.1 dB. It is known that if the optical power of one band (C-band or L-band) is fixed, for every 3 dB increase in power in the other band, the standard value increases by approximately 0.1 dB. 21 represents 19–21 dBm (inclusive of 21–21.5 dBm), and 24 represents 22–24 dBm (inclusive of 21.5–22 dBm).

[0109] This invention combines engineering practice and further provides values ​​for b1 to b4. The example is a C+L full-wavelength system, over 40km long, using G.652 fiber, with a single-wavelength input optical power greater than 19dBm. Common amplifier configurations of 21dB and 24dB are shown in Tables 1 and 2 below, covering 19–21dBm and 22–24dBm cases. Other cases can be considered extensions of this example. Further values ​​for b1 to b4 can be derived using the same method, which will not be elaborated upon here but can be considered extensions of this invention.

[0110] Table 1. Examples of standard values ​​for optical power loss in the C-band under different C+L combinations.

[0111] Table 2. Examples of standard values ​​for optical power loss in the L-band under different C+L combinations.

[0112] Secondly, embodiments of this application also provide an operation and maintenance monitoring device for a multi-band optical communication system.

[0113] In one embodiment, referring to FIG10, FIG10 is a functional block diagram of an embodiment of the operation and maintenance monitoring device for a multi-band optical communication system according to the present application. As shown in FIG10, the operation and maintenance monitoring device for a multi-band optical communication system includes:

[0114] Preprocessing module 1 is used to construct a channel loss difference table, which includes standard values ​​of the optical power loss difference of one target band when an optical path failure occurs in any target band. The aforementioned optical power loss difference represents the change in the optical power difference of the target band before and after multiplexing transmission.

[0115] Monitoring module 2 is used to acquire the real-time value of the optical power loss difference between the two target bands. When the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path fault has occurred in the other target band.

[0116] In this embodiment, compared to traditional solutions that are limited to detecting optical path fault events within the same band (e.g., detecting changes in optical power loss downstream of the C-band to obtain fault information upstream of the C-band), this invention transcends the C-band scope. It can obtain C-band fault information by detecting changes in optical power downstream of the L-band. Similarly, it can obtain L-band fault information by detecting changes in optical power downstream of the C-band. This invention utilizes the instantaneous characteristics of local optical power changes to promptly and accurately obtain fault information in adjacent bands, avoiding the drawbacks of relaying fault information through third-party software. It solves the problem of intercommunication between C-band and L-band fault information in a split C+L system, thereby enabling simultaneous bi-directional switching of both bands at the moment of a C+L fault; that is, when only one band (C-band or L-band) fails, both L-band and C-band switch simultaneously.

[0117] The functions of each module in the operation and maintenance monitoring device of the above-mentioned multi-band optical communication system correspond to the steps in the operation and maintenance monitoring method embodiment of the above-mentioned multi-band optical communication system. Their functions and implementation processes will not be described in detail here.

[0118] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0119] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0120] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0121] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0122] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0123] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0124] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for operation and maintenance monitoring of a multi-band optical communication system, characterized in that, The system includes two target bands configured in full-wave configuration; the method includes: A channel loss difference table is constructed, which includes the standard value of the optical power loss difference of another target band when an optical path failure occurs in any target band; the optical power loss difference is the change in optical power difference of the target band before and after multiplexing transmission. Obtain the real-time value of the optical power loss difference between the two target bands; When the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path failure has occurred in another target band.

2. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 1, characterized in that, Obtaining the real-time value of the optical power loss difference between the two target bands specifically includes the following steps: Input power is collected at the output side of the multiplexer in a multi-band optical communication system, and output power is collected at the output side of the demultiplexer. Optical power loss is obtained from the difference between output power and input power; The optical power loss difference is obtained by measuring the difference between two consecutive optical power losses.

3. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 1, characterized in that, The two target bands are C-band and L-band; the construction of the channel loss difference table specifically includes the following steps: Multiple channels in the C-band full-channel array are selected as C sampling channels, and a standard value for the difference in optical power loss of each C sampling channel is set when an optical path failure occurs in the L-band. Multiple channels in the full-wavelength L-band are selected as L-sampling channels, and a standard value for the difference in optical power loss of each L-sampling channel is set when an optical path failure occurs in the C-band. The channel loss difference table is constructed based on the standard values ​​of all the C-sampled channels and L-sampled channels.

4. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 3, characterized in that, According to the order of wavelength from longest to shortest, one channel is selected from every four channels in the full channel of the C-band as the C sampling channel, and a standard value for the difference in optical power loss of each C sampling channel is set when an optical path failure occurs in the L-band. Following the order of wavelength from longest to shortest, one channel out of every four channels in the full-channel L-band is selected as the L sampling channel, and a standard value for the difference in optical power loss of each L sampling channel is set when an optical path failure occurs in the C-band.

5. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 3, characterized in that, Before determining whether an optical path fault has occurred in another target band based on the real-time value and the corresponding standard value of one target band, the method further includes: Multiple channels from all C sampling channels are selected as C monitoring channels; when the real-time values ​​of all C monitoring channels are greater than the preset trigger value of the optical power loss difference, the triggering stage is entered to determine the optical path fault in the L band.

6. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 3, characterized in that, Before determining whether an optical path fault has occurred in another target band based on the real-time value and the corresponding standard value of one target band, the method further includes: Multiple channels from all L sampling channels are selected as L monitoring channels; when the real-time values ​​of all L monitoring channels are greater than the preset trigger value of the optical power loss difference, the triggering stage is entered to determine the optical path fault in the C band.

7. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 1, characterized in that, The step of determining whether an optical path fault has occurred in another target band based on the real-time value of one target band and the corresponding standard value specifically includes the following steps: When the real-time value of a target band is greater than the corresponding standard value, a monitoring message is obtained from the optical monitoring channel of the target band, and the target band itself is judged based on the message to determine whether there is an optical path failure. If so, the judgment is terminated; otherwise, it is determined that there is an optical path failure in another target band.

8. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 5, characterized in that, The process of determining whether a real-time value of a target band is greater than a corresponding standard value includes the following steps: The channel with the longest wavelength in the C sampling channels is designated as the first C calibration channel, and the channel with the shortest wavelength is designated as the second C calibration channel. When it is determined that the real-time value of the second C calibration channel is greater than the corresponding standard value and the real-time value of the first C calibration channel is greater than the real-time value of the second C calibration channel, it is determined that the real-time value of the C band is greater than the corresponding standard value.

9. The operation and maintenance monitoring method for a multi-band optical communication system as described in claim 6, characterized in that, The process of determining whether a real-time value of a target band is greater than a corresponding standard value includes the following steps: The channel with the longest wavelength in the L sampling channels is designated as the first L calibration channel, and the channel with the shortest wavelength is designated as the second L calibration channel. When it is determined that the real-time value of the second L calibration channel is greater than the corresponding standard value and the real-time value of the first L calibration channel is greater than the real-time value of the second L calibration channel, it is determined that the real-time value of the L band is greater than the corresponding standard value.

10. A maintenance and monitoring device for a multi-band optical communication system, characterized in that, The device includes: The preprocessing module is used to construct a channel loss difference table, which includes a standard value of the optical power loss difference of another target band when an optical path failure occurs in any target band; the optical power loss difference is the change in optical power difference of the target band before and after multiplexing transmission. The monitoring module is used to obtain the real-time value of the difference in optical power loss between the two target bands; when the real-time value of one target band is greater than the corresponding standard value, it is determined that an optical path fault has occurred in the other target band.

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