Optical switching device and optical communication transmission system

Abstract

The invention relates to an optical switching device and an optical communication transmission system. The device comprises an optical switching unit, an optical switching sending unit, an optical switching receiving unit and a control unit, the optical switching transmitting unit comprises at least two groups of transmitting lines, and the optical switching receiving unit comprises at least two groups of receiving lines; the optical switching unit comprises a first switching subunit and a second switching subunit; the sending line is used for monitoring the power of each wave channel of signal light of a sending station; the control unit is used for determining a corresponding power change value when the power of the signal light of the sending station changes, and sending the power change value to the light switching receiving unit of the receiving station; the receiving line is used for determining and adjusting a switching threshold value of the second switching subunit according to the power change value; and the second switching subunit is used for carrying out line switching when the received signal optical power is smaller than the updated switching threshold. According to the invention, the problems of wrong line switching and long switching time delay in the existing multi-wave transmission system can be solved.

Description

Technical Field

[0001] The invention relates to an optical switching device and an optical communication transmission system. Background Art

[0002] Optical line protection technology is a very critical technology in modern communications. It mainly provides backup protection for optical transmission lines, generally in a one-master-one-backup mode. When the main line fails, in order not to affect the actual business, the business will be immediately switched to the backup line, thereby realizing backup protection for the line. Optical line protection is mainly completed by optical switching devices. The basis for the current optical switching device to switch between the main and backup lines is mainly to determine whether the optical power at the receiving end of the line is less than the switching threshold. If it is less than the switching threshold, it means that the line has a fault and needs to be switched to the backup line immediately. The switching threshold is set when the line project is initially opened. It is generally not changed after setting, or it is adjusted manually according to the actual situation in special circumstances.

[0003] On the other hand, for some special services, such as power relay protection services, the switching delay requirements for the main and backup lines are very high and need to be within 25ms. Figure 1 As shown, it is a typical optical communication transmission system in the prior art. Since the erbium-doped fiber amplifier amplifies the signal light by exciting the erbium-doped fiber with a pump laser, when there is signal light in the erbium-doped fiber, the signal light will be amplified. When there is no signal light in the erbium-doped fiber, the erbium-doped fiber will generate spontaneous emission light (Amplified Spontaneous Emission, abbreviated as: ASE) with high energy under the stimulation of the pump light. Therefore, for the erbium-doped fiber amplifier, whether there is an optical signal input or not, there will be an optical signal output as long as the pump laser is not turned off. In other words, when the line is interrupted, if the pump laser of the erbium-doped fiber amplifier is not turned off, the optical switching device will always detect the presence of light, and the optical switching device will not switch until the pump laser of the erbium-doped fiber amplifier is turned off and the optical switching device detects that there is no optical signal. The time from the erbium-doped fiber amplifier itself detecting that the fiber is interrupted and there is no input signal light to turning off the pump laser is generally relatively long, which leads to a long switching delay of the optical switching device after the line is interrupted, affecting the stability of the service. Summary of the invention

[0004] In order to solve the problem of line mis-switching in the existing multi-wave transmission system and reduce the switching delay of the optical switching device, the present invention proposes an optical switching device and an optical communication transmission system. The technical solution proposed by the present invention is as follows:

[0005] In a first aspect, the present invention provides an optical switching device, comprising: an optical switching unit, an optical switching sending unit, an optical switching receiving unit and a control unit, wherein:

[0006] The optical switching sending unit includes at least two groups of sending lines, and the optical switching receiving unit includes at least two groups of receiving lines;

[0007] The optical switching unit includes a first switching subunit and a second switching subunit;

[0008] The transmission line is used to monitor the power of each channel of the signal light of the transmission site, and when the power of the signal light of the transmission site changes, determine the corresponding power change value;

[0009] The receiving circuit is used to determine and adjust the switching threshold of the second switching subunit according to the power change value to obtain an updated switching threshold; and detect the received signal optical power;

[0010] The second switching subunit is used to perform line switching between the at least two groups of receiving lines when the received signal optical power is less than the updated switching threshold;

[0011] The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site; and is also used to generate a switching command and send it to the first switching subunit of the sending site after the second switching subunit of the receiving site switches the at least two groups of receiving lines;

[0012] The first switching subunit is used to perform line switching between the at least two groups of sending lines after receiving the switching command.

[0013] In one or some embodiments, the transmission line includes a power monitoring subunit, a first optical amplifier access port, a photoelectric detection subunit and a line transmission port connected in sequence;

[0014] The transmission line further comprises an optical monitoring channel module, the transmission side of which is connected to the power monitoring subunit;

[0015] The power monitoring subunit is used to monitor the power of each channel of the sending site signal light, divide the sending site signal light into a first optical signal and a first optical power monitoring signal, determine the power change value according to the first optical power monitoring signal and send it to the control unit;

[0016] The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site according to the working mode of the optical amplifier connected to the first optical amplifier access port;

[0017] The optical monitoring channel module is used to send the power change value to the receiving line of the receiving site;

[0018] The photoelectric detection subunit is used to generate a second optical signal and a first optical detection signal based on the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port, and send the second optical signal to the line sending port.

[0019] In one or some embodiments, the power monitoring subunit includes a first wavelength division multiplexer, an optical attenuator, and a first optical splitter connected in sequence;

[0020] The power monitoring subunit further includes an optical channel monitoring module, and the optical channel monitoring module is connected to the output end of the first optical splitter;

[0021] The first wavelength division multiplexer connects the transmitting side of the optical supervisory channel module and the first switching subunit;

[0022] The first wavelength division multiplexer is used to couple the sending site signal light with the first optical monitoring signal of the optical monitoring channel module to generate a first combined optical signal;

[0023] The optical attenuator is used to adjust the optical power of the first combined optical signal to obtain an attenuated signal;

[0024] The first optical splitter is used to split the attenuated signal into a first optical signal and a first power monitoring signal according to a first preset ratio, and send the first optical signal to the optical amplifier connected to the first optical amplifier access port, and send the first power monitoring signal to the optical channel monitoring module.

[0025] In one or some embodiments, the photodetection subunit includes a second beam splitter and a first photodetector;

[0026] The input end of the second optical splitter is connected to the first optical amplifier access port, and the output end of the second optical splitter is connected to the first photodetector and the line sending port;

[0027] The second optical splitter is used to split the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port into a second optical signal and a first optical detection signal according to a second preset ratio, and send the second optical signal to the line sending port, and send the first optical detection signal to the first photodetector.

[0028] In one or some embodiments, the receiving line includes a line receiving port, a third optical splitter, a second optical amplifier access port, and a second wavelength division multiplexer connected in sequence;

[0029] The receiving circuit and the sending circuit share the optical monitoring channel module;

[0030] The receiving circuit further includes a second photodetector, and the second photodetector is connected to the output end of the third optical splitter;

[0031] The output end of the second wavelength division multiplexer is connected to the receiving side of the optical supervisory channel module and the second switching subunit respectively;

[0032] The third optical splitter is used to split the optical signal received by the line receiving port into a third optical signal and a second optical detection signal according to a third preset ratio, and send the third optical signal to the second optical amplifier access port, and send the second optical detection signal to the second photodetector;

[0033] The second wavelength division multiplexer is used to divide the third optical signal amplified by the optical amplifier connected through the second optical amplifier access port into a second optical monitoring signal and a fourth optical signal, and send the second optical monitoring signal to the optical monitoring channel module, and send the fourth optical signal to the second switching subunit.

[0034] In one or some embodiments, the updated switching threshold is determined by the following formula:

[0035] P = P0 + β + Δ;

[0036] Where P is the updated switching threshold, P0 is the initial signal power detected by the second photoelectric detector when the line project is opened, β is the line system margin, and Δ is the power change value.

[0037] In one or some embodiments, the control unit is further used for:

[0038] The line loss is determined according to the first optical detection signal and the second optical detection signal; if the line losses of the main line and the backup line are inconsistent, a loss adjustment value is determined according to the line losses of the main line and the backup line, and the loss adjustment value is transmitted to the optical switching sending unit; and the parameters of the optical attenuators of the at least two groups of sending lines are adjusted according to the loss adjustment value to make the line losses of the main line and the backup line consistent.

[0039] In one or some embodiments, the operating mode of the optical amplifier connected to the first optical amplifier access port includes a constant gain mode and a constant power output mode;

[0040] The control unit is used to control the optical monitoring channel module to send the power change value to the optical switching receiving unit of the receiving site if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant gain mode; if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant power output mode, the power change value is not sent to the receiving line of the receiving site.

[0041] In one or some embodiments, the first photodetector is further used to detect the initial optical power when the line is connected and the optical power after each change of the attenuation value of the optical attenuator;

[0042] The control unit is used to determine that the operating mode of the optical amplifier connected to the first optical amplifier access port is a constant gain mode if the optical power received after each change of the attenuation value of the optical attenuator is the sum of the initial optical power and the attenuation value; and to determine that the operating mode of the optical amplifier connected to the first optical amplifier access port is a constant output power mode if the optical power received after each change of the attenuation value of the optical attenuator remains unchanged.

[0043] In a second aspect, the present invention provides an optical communication transmission system, characterized in that both a transmitting end and a receiving end of the optical communication transmission system are provided with an optical switching device as described in the first aspect.

[0044] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0045] The optical switching device provided by the present invention monitors the power of each channel of the signal light of the sending site through the sending line. When the power of the signal light of the sending site changes, the corresponding power change value is determined and sent to the optical switching receiving unit of the receiving site, so that the optical switching device of the receiving site can perceive the change of the signal light power of the sending site in real time, thereby adjusting the switching threshold of the second switching subunit according to the power change value, and realizing the self-adaptation of the switching threshold. When the received signal light power is less than the updated switching threshold, the line switching is performed between at least two groups of receiving lines, solving the problem of line mis-switching in the existing multi-wave transmission system.

[0046] Compared with the prior art method in which the optical switching device switches the primary and backup lines only when it detects that there is no optical signal when the pump laser of the erbium-doped fiber amplifier is turned off, the optical switching device of the present invention is not affected by the pump-off time of the optical amplifier when performing line switching, which greatly reduces the switching delay of the optical switching device and can meet the switching delay requirements of more special services.

[0047] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 is a schematic structural diagram of a typical optical communication transmission system in the prior art provided by an embodiment of the present invention;

[0051] Figure 2 is a schematic structural diagram of an optical switching device provided by an embodiment of the present invention;

[0052] Figure 3 is a structural schematic diagram of an optical switching sending unit of an optical switching device provided by an embodiment of the present invention;

[0053] Figure 4 is a structural schematic diagram of an optical switching receiving unit of an optical switching device provided by an embodiment of the present invention;

[0054] Figure 5 is a schematic diagram of the structure of an optical communication transmission system provided by an embodiment of the present invention;

[0055] Figure 6 It is a schematic diagram of the structure of an optical communication transmission system without an optical amplifier provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0058] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] The inventor found in his work that for some special services, such as power relay protection services, the switching delay requirements for the main and standby lines are very high, which needs to be within 25ms. When the line is interrupted, the optical amplifier at the receiving end of the line detects that there is no signal and turns off the pump laser. Only when the pump laser is turned off, the optical switching device cannot detect the optical signal, and then the switching is performed. Since the pump-off process of the optical amplifier takes a long time, this leads to a long switching delay of the optical switching device, which affects the stability of these special services and cannot meet the inventor's expectations. After further research and development, the inventor made the present invention. The present invention relates to the field of optical communication technology, and specifically to an optical switching device and a transmission system.

[0061] Embodiment 1

[0062] An embodiment of the present invention provides an optical switching device, referring to Figure 2 and Figure 3 As shown, it includes: an optical switching unit 1, an optical switching sending unit 81, an optical switching receiving unit 82 and a control unit (not shown in the figure).

[0063] The optical switching sending unit 81 includes at least two groups of sending lines, and the optical switching receiving unit 82 includes at least two groups of receiving lines;

[0064] Reference Figure 3As shown, the optical switching sending unit 81 and the optical switching receiving unit 82 share an optical switching unit 1 (i.e., a switching switch), which is used to switch the primary and backup lines of the optical switching sending unit 81 and the optical switching receiving unit 82, that is, in this application, the unit connecting the at least two groups of sending lines is called the first switching subunit, and the unit connecting the at least two groups of receiving lines is called the second switching subunit.

[0065] The transmission line is used to monitor the power of each channel of the signal light of the transmission site, and when the power of the signal light of the transmission site changes, determine the corresponding power change value;

[0066] The receiving circuit is used to determine and adjust the switching threshold of the second switching subunit according to the power change value to obtain an updated switching threshold; and detect the received signal optical power;

[0067] The second switching subunit is used to perform line switching between the at least two groups of receiving lines when the received signal optical power is less than the updated switching threshold;

[0068] The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site; and is also used to generate a switching command and send it to the first switching subunit of the sending site after the second switching subunit of the receiving site switches the at least two groups of receiving lines;

[0069] The first switching subunit is used to perform line switching between the at least two groups of sending lines after receiving the switching command.

[0070] The present invention can satisfy the line synchronous switching of the optical switching sending unit 81 and the optical switching receiving unit 82 of the optical switching device 8. When the optical switching receiving unit 82 of the optical switching device 8 meets the switching condition and switches quickly, the switching command is sent to the optical switching sending unit 81 at the same time. After receiving the switching command, the optical switching sending unit 81 performs line switching between the at least two groups of sending lines through the first switching subunit, and completes the main and standby line switching of the optical switching sending unit 81.

[0071] In an optional embodiment, each group of transmission lines of the above-mentioned optical switching transmission unit 81, namely the main line and the backup line, have the same composition, and both include a power monitoring subunit 811, a first optical amplifier access port, a photoelectric detection subunit 812 and a line transmission port connected in sequence.

[0072] The transmission line further includes an optical supervisory channel (Optical Supervisory Channel, abbreviated as: OSC) module (hereinafter referred to as OSC module), and the transmission side tx of the OSC module is connected to the power monitoring subunit.

[0073] Reference Figure 2 and Figure 3 As shown, the line sending port of the main line is recorded as the main line sending port T1, which is used to connect the main line sending end; the line sending port of the backup line is recorded as the backup line sending port T2, which is used to connect the backup line sending end.

[0074] Each device in each group of transmit lines performs the same operation when used, as follows:

[0075] The power monitoring subunit 811 is used to monitor the power of each channel of the sending site signal light, divide the sending site signal light into a first optical signal and a first optical power monitoring signal, determine the power change value according to the first optical power monitoring signal and send it to the control unit;

[0076] The optical amplifier connected to the first optical amplifier access port is used to amplify the first optical signal to obtain an amplified first optical signal;

[0077] The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site according to the working mode of the optical amplifier connected to the first optical amplifier access port;

[0078] The OSC module is used to send the power change value to the receiving line of the receiving site;

[0079] The photoelectric detection subunit 812 is used to generate a second optical signal and a first optical detection signal based on the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port, and send the second optical signal to the line sending port.

[0080] In an alternative embodiment, referring to Figure 3 As shown, the power monitoring subunit 811 includes a first wavelength division multiplexer, an optical attenuator and a first optical splitter which are connected in sequence.

[0081] The first wavelength division multiplexer is used to combine and split the signal light and OSC monitoring light, the optical attenuator is used to adjust the optical power, and the first optical splitter is used to separate part of the signal light. Figure 3 The first wavelength division multiplexer of the main line is denoted as 21, and the first wavelength division multiplexer of the backup line is denoted as 22. The optical attenuator of the main line is denoted as 41, and the optical attenuator of the backup line is denoted as 42. The first optical splitter of the main line is denoted as 51, and the first optical splitter of the backup line is denoted as 52.

[0082] The power monitoring subunit 811 also includes an optical channel monitoring (OCM) module (hereinafter referred to as the OCM module). The OCM module scans two parameters, one is the number of signal channels, and the other is the power value of each channel. The change in the number of channels will also change the corresponding power value. Therefore, when it is found that the number of channels has changed, the OCM module will record the change value of the corresponding power. In this embodiment, the OCM module in the prior art can be used, and the present invention application does not limit this structure.

[0083] The first wavelength division multiplexer connects the sending side tx of the OSC module and the first switching subunit. The OSC module is used to monitor the transmission status of each channel in the sending site to obtain a first optical monitoring signal. In the optical switching sending unit 81, the first optical monitoring signal is combined with the optical signal of the main channel, that is, the sending site signal light for output. The first wavelength division multiplexer is used to couple the sending site signal light with the first optical monitoring signal of the OSC module to generate a first combined optical signal.

[0084] The optical attenuator is used to adjust the optical power of the first combined optical signal to obtain an attenuated signal.

[0085] The OCM module is connected to the output end of the first optical splitter; the first optical splitter is used to split the attenuated signal into a first optical signal and a first power monitoring signal according to a first preset ratio, and send the first optical signal to the optical amplifier connected to the first optical amplifier access port, and send the first power monitoring signal to the OCM module. The OCM module determines the power change value according to the first power monitoring signal. The process can refer to the description of OCM in the prior art and will not be repeated here.

[0086] The optical amplifier connected to the first optical amplifier access port amplifies the first optical signal to obtain an amplified first optical signal.

[0087] In an alternative embodiment, referring to Figure 3 As shown, the photodetection subunit 812 includes a second spectrometer and a first photodetector.

[0088] The second optical splitter is used to separate part of the signal light. Figure 3 As shown, the second optical splitter of the main line is marked as 53, and the second optical splitter of the backup line is marked as 54.

[0089] The input end of the second optical splitter is connected to the first optical amplifier access port, and the output end of the second optical splitter is connected to the first photodetector and the line sending port;

[0090] The second optical splitter is used to split the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port into a second optical signal and a first optical detection signal according to a second preset ratio, and send the second optical signal to the line sending port, and send the first optical detection signal to the first photodetector. The second optical signal is sent to the receiving site through the line sending port through the main path or the backup path. The second optical signal sent from the line sending port can be determined based on the first optical detection signal of the first photodetector and the second preset ratio of the second optical splitter.

[0091] In an alternative embodiment, referring to Figure 4 As shown, each group of receiving lines of the optical switching receiving unit 82, namely the main line and the backup line, have the same composition, and both include a line receiving port, a third optical splitter, a second optical amplifier access port and a second wavelength division multiplexer connected in sequence.

[0092] For the convenience of distinction, Figure 4 As shown, the second wavelength division multiplexer of the main line is denoted as 23, and the second wavelength division multiplexer of the backup line is denoted as 24. The third optical splitter of the main line is denoted as 55, and the third optical splitter of the backup line is denoted as 56.

[0093] The receiving circuit and the sending circuit share the OSC module; Figure 3 As shown, the embodiment of the present invention is described by taking the optical switching sending unit 81 including two groups of sending lines, a main line and a backup line, and the optical switching receiving unit 82 including two groups of sending lines, a main line and a backup line, as an example.

[0094] The above OSC module is used for communication between optical switching devices at two sites. The main lines of the optical switching sending unit 81 and the optical switching receiving unit 82 of the same optical switching device share the same OSC module, and the backup lines of the optical switching sending unit 81 and the optical switching receiving unit 82 share the same OSC module. Figure 3 and Figure 4 As shown, the main lines of the optical switching sending unit 81 and the optical switching receiving unit 82 share the first OSC module 31 , and the backup lines of the optical switching sending unit 81 and the optical switching receiving unit 82 share the second OSC module 32 .

[0095] The receiving circuit further includes a second photodetector, and the second photodetector is connected to the output end of the third optical splitter;

[0096] The output end of the second wavelength division multiplexer is connected to the receiving side rx of the OSC module and the second switching subunit respectively.

[0097] The OSC module is used to monitor the transmission status of each channel in the receiving site to obtain the second optical monitoring signal. In the optical switching receiving unit 82, the second optical monitoring signal is separated from the received optical signal.

[0098] Each device in each receive line performs the same operation when used, as follows:

[0099] The third optical splitter is used to split the optical signal received by the line receiving port into a third optical signal and a second optical detection signal according to a third preset ratio, and send the third optical signal to the second optical amplifier access port, and send the second optical detection signal to the second photodetector. The third optical signal can be determined according to the second optical detection signal and the third preset ratio. The second photodetector is used to convert the second optical detection signal into an electrical signal.

[0100] The second wavelength division multiplexer is used to divide the third optical signal amplified by the optical amplifier connected to the second optical amplifier access port into a second optical monitoring signal and a fourth optical signal, and send the second optical monitoring signal to the OSC module, and send the fourth optical signal to the second switching subunit. The second switching subunit sends the fourth optical signal to a receiving site.

[0101] The second switching subunit is used to switch between the at least two groups of receiving lines when the second optical detection signal is less than the updated switching threshold, so as to complete the switching of the primary and backup lines of the receiving site.

[0102] The same station can be used as both a sending station and a receiving station. Figure 5 As shown, when serving as a sending site, the optical switching sending unit 81 of the optical switching device 8 serves as a sending end, and communicates with the optical switching receiving unit 82 of the receiving site through the OSC module. When serving as a receiving site, the optical switching receiving unit 82 of the optical switching device 8 serves as a receiving end, and communicates with the optical switching sending unit 81 of the sending site through the OSC module.

[0103] In the embodiment of the present invention, the OSC module transmits a wavelength in the C band, which can be amplified by an optical amplifier and does not occupy a service signal channel. The second photoelectric detector can be replaced by an OCM module.

[0104] Each device in the above-mentioned optical switching sending unit 81 and the optical switching receiving unit 82, namely the first switching subunit, the second switching subunit, the OSC module, the optical attenuator, the OCM module, the first photodetector and the second photodetector is controlled by a control unit, so data can be processed quickly and instructions can be issued.

[0105] The first photoelectric detector is used to monitor the signal light power. Figure 3As shown, the first photodetector of the main line of the optical switching sending unit 81 is denoted as 71, and the first photodetector of the standby line is denoted as 72. The second photodetector of the main line of the optical switching receiving unit 82 is denoted as 73, and the second photodetector of the standby line is denoted as 74.

[0106] The first optical amplifier access port and the second optical amplifier access port are used to access the optical amplifier. Figure 2 and Figure 3 ,like Figure 5 The first optical amplifier access port a1 and b1 are used to access the optical amplifier of the main line; the first optical amplifier access port a2 and b2 are used to access the optical amplifier of the backup line. Figure 2 and Figure 4 ,like Figure 5 The second optical amplifier is connected between ports c1 and d1 to connect to the optical amplifier of the main line; the second optical amplifier is connected between ports c2 and d2 to connect to the optical amplifier of the backup line.

[0107] The OCM module is used to monitor the power of each channel of the signal light of the sending site, and when the power of the signal light of the sending site changes, determine the corresponding power change value, and obtain the working mode of the optical amplifier connected to the first optical amplifier access port; for the convenience of distinction, refer to the attached Figure 3 As shown, in the present invention, the OCM module of the main line is marked as 61, and the OCM module of the standby line is marked as 62.

[0108] When the present invention switches the primary and backup lines, the comparison between the power of the second optical detection signal detected by the second photodetector of the receiving line of the receiving station and the switching threshold determines whether to switch, and is not affected by the working mode of the optical amplifier connected to the second optical amplifier access port c1, d1, c2, d2 of the optical switching receiving unit 82. Therefore, there is no need to judge the working mode of the optical amplifier connected to the optical switching receiving unit 82.

[0109] When the signal optical power detected by the second photoelectric detector of the main line or the backup line of the optical switching receiving unit 82 is less than the updated switching threshold, it means that there is a problem with the line and needs to be switched, and the second switching subunit switches the main line and the backup line. The calculation method of the updated switching threshold is:

[0110] P = P0 + β + Δ;

[0111] In the formula, P is the updated switching threshold, P0 is the initial signal power detected by the second photoelectric detector when the line project is opened, β is the line system margin, which is generally 5dB according to the engineering construction specifications, and Δ is the power change value of the sending site, which is detected by the OCM module 61 of the main line or the OCM module 62 of the backup line, and sent to the optical switching device 8 of the receiving site by the OSC module 31 of the main line or the OSC module 32 of the backup line. The control unit of the optical switching device 8 of the receiving site sets the switching threshold of the second switching subunit to the above-mentioned updated switching threshold. Therefore, the switching threshold of the second switching subunit will change with the change of the signal optical power of the sending site.

[0112] The process of switching the main and standby lines of the present invention is as follows: the initial state signal light enters the line from the main line through the optical switching sending unit 81 of the optical switching device 8, and the OCM module monitors the initial power of different channels of the signal light. When the signal light power changes, such as increasing or decreasing the wave number, the OCM module monitors the power change and transmits the power change value to the optical switching device 8 of the receiving site through the OSC module. The optical switching device 8 of the receiving site automatically adjusts the switching threshold of the second switching subunit according to the power change value to achieve self-feedback adjustment of the switching threshold. The optical switching device 8 provided in the embodiment of the present invention can automatically change the switching threshold of the second switching subunit of the receiving site according to the change of the signal light power of the sending site, and after adjusting the switching threshold of the second switching subunit, the second photodetector is used to detect the received signal light power. When the signal light power is less than the updated switching threshold, the main line and the standby line can be quickly switched. The photodetector does not have the complicated pump-off process in the optical amplifier, so it can achieve fast switching. This not only solves the problem of false switching caused by the switching threshold of the optical switching device in the multi-wave transmission system, but also solves the problem of prolonged switching time caused by the slow pump shutdown of the erbium-doped fiber amplifier in the traditional multi-wave transmission system, greatly reducing the switching delay of the erbium-doped fiber amplifier system.

[0113] In addition, the inventors have also tried to apply the present invention to a multi-wave transmission system, and have also achieved unexpected results. Specifically, for a multi-wave transmission system, it is very common for the transmitter to add or reduce channels. Since the change in the number of channels at the transmitter will cause the optical power at the transmitter to change, thereby affecting the signal optical power at the receiver, for example, if the transmitter reduces 10 waves, the total optical power will decrease by 10dBm. At this time, the total optical power at the receiving end of the line will also decrease by 10dBm, which may be less than the switching threshold, resulting in line switching. However, the reduction in total optical power is not caused by line degradation, but by the reduction of channels at the transmitter, which results in erroneous switching. The optical switching device of the present invention can adaptively adjust the switching threshold of the receiving end as the transmitter increases or decreases channels, thereby avoiding erroneous switching.

[0114] Reference Figure 2 and Figure 3 As shown, the optical switching sending unit 81 of the optical switching device 8 also has a sending port Tx, and the optical switching receiving unit 82 has a receiving port Rx:

[0115] The sending port Tx is used to receive local services and is connected to the local signal sending terminal;

[0116] The receiving port Rx is used to send services to the local area and is connected to the local receiving signal terminal.

[0117] In an optional embodiment, the operation mode of the optical amplifier connected to the first optical amplifier access port includes a constant gain mode and a constant power output mode;

[0118] The control unit is used to control the OSC module to send the power change value to the optical switching receiving unit 82 if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant gain mode; if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant power output mode, the OSC module does not send the power change value to the optical switching receiving unit 82.

[0119] The threshold self-feedback mode implemented by the present invention is: at the initial stage of line opening or the initial stage of the optical switching device 8 accessing the line, the optical switching device 8 will initialize the detection to determine whether the working mode of the optical amplifier accessed by the optical switching sending unit 81 of the optical switching device 8 through the first optical amplifier access port a1, b1, a2, b2 is a constant gain mode or a constant power output mode. If it is a constant gain mode, it means that the power of the line sending end will change due to the change of the business wave number (increasing the wave number, reducing the wave number, etc.). If it is a constant power output mode, it means that the power of the line sending end will not change due to the change of the business wave number. After the initialization detection is completed, the OCM module of the sending line will continuously scan the power of each channel of the signal light of the sending site and record the value. When it is found that the business wave number has changed, the OCM module of the optical switching device 8 will record the corresponding power change value. If the working mode of the accessed optical amplifier is a constant gain mode, the power change value is sent from the sending site to the receiving site through the sending side tx of the OSC module, and is received by the receiving side rx of the OSC module of the receiving site. The optical switching receiving unit 82 of the optical switching device 8 of the receiving site adjusts the switching threshold of the second switching subunit according to the power change value; if the working mode of the optical amplifier connected to the first optical amplifier access port is the constant power output mode, the OSC module will not send the power change value, and the receiving site will keep the switching threshold unchanged if it does not receive the power change value. Thus, the switching threshold of the optical switching device 8 changes according to the signal optical power change of the sending site, and is not limited by the working mode of the optical amplifier connected to the optical switching receiving unit 82.

[0120] In an optional embodiment, the optical switching device 8 implements fast switching in the following manner: when the line is interrupted, the second photodetector of the main line or the backup line in the optical switching receiving unit 82 of the optical switching device 8 will interrupt the reception of the signal interruption information light. At this time, the second photodetector will immediately transmit the signal interruption information to the control unit, and the control unit controls the second switching subunit to switch the line to the backup line or the main line. If the line currently in use is the main line, switch to the backup line. If the line currently in use is the backup line, switch to the main line. Specifically, the control unit is also used to: when the line is interrupted, control the second photodetector to interrupt the reception of the signal light, and generate signal interruption information to be transmitted to the second switching subunit;

[0121] The second switching subunit is used to perform line switching between the at least two groups of receiving lines after receiving the signal interruption information, so as to complete the switching of the primary and backup lines of the receiving site.

[0122] The control unit is further configured to generate a switching command and send it to the first switching subunit of the sending site after the second switching subunit of the receiving site switches the primary and backup lines;

[0123] The first switching subunit is configured to perform line switching between the at least two groups of sending lines after receiving the switching command, so as to complete the switching of the primary and backup lines of the sending site.

[0124] In an optional embodiment, the first photodetector of the optical switching sending unit 81 is also used to detect the initial optical power P1 when the line is connected and the optical power P2 after each change of the attenuation value of the optical attenuator;

[0125] The control unit is used to determine that the working mode of the optical amplifier connected to the first optical amplifier access end is a constant gain mode if the optical power received after each change of the attenuation value of the optical attenuator is the sum of the initial optical power and the attenuation value; and to determine that the working mode of the optical amplifier connected to the first optical amplifier access end is a constant output power if the optical power received after each change of the attenuation value of the optical attenuator remains unchanged.

[0126] The initialization detection process of the optical switching device 8 is as follows: when the optical switching device 8 is initially connected to the line, the first photodetector will detect the size of the received optical power at this time to obtain the initial optical power P1, then increase the attenuation value α of the optical attenuator, detect the detection power of the first photodetector again, and obtain the received optical power P2 after changing the attenuation value of the optical attenuator, and repeat this process 3 to 5 times. The control unit performs calculations, and if P2 is the sum of P1 and the α value each time, it means that the working mode of the optical amplifier connected to the first optical amplifier access port a1, b1, a2, and b2 is a constant gain mode; if it is detected that P2 remains unchanged, it means that the working mode of the optical amplifier connected to the first optical amplifier access port a1, b1, a2, and b2 is a constant output power mode.

[0127] In an optional embodiment, the optical attenuator is used for initialization detection and line attenuation compensation. When the project is opened, in order to ensure that the switching of the main and backup lines does not affect the service performance, the attenuation of the short line will be increased to ensure that the main and backup lines have the same attenuation.

[0128] The control unit is further used to determine the line loss according to the first optical detection signal and the second optical detection signal; if the line losses of the main line and the backup line are inconsistent, determine the loss adjustment value according to the line losses of the main line and the backup line, and transmit the loss adjustment value to the optical switching transmission unit; adjust the parameters of the optical attenuators of the at least two groups of transmission lines according to the loss adjustment value to make the line losses of the main line and the backup line consistent. The above optical attenuator can complete the attenuation compensation function of the main and backup lines without adding an external optical attenuator.

[0129] Specifically, the attenuation of the main line is determined according to the first optical detection signal and the second optical detection signal of the main line; the attenuation of the backup line is determined according to the first optical detection signal and the second optical detection signal of the backup line. If the attenuation of the main line is inconsistent with the attenuation of the backup line, the attenuation adjustment value is determined according to the attenuation of the main line and the attenuation of the backup line, and the attenuation adjustment value is transmitted to the optical switching sending unit; the above-mentioned attenuation adjustment value is determined according to the difference between the attenuation of the main line and the attenuation of the backup line. For example, when the attenuation of the main line is 30dB and the attenuation of the backup line is 25dB, the attenuation adjustment value is 5dB, and the backup line needs to be increased by 5dB. After determining the attenuation adjustment value, the sending site is notified through the OSC module, and the control unit of the sending site adjusts the value of the optical attenuator of the backup line.

[0130] The specific structures of the OSC module and the OCM module in the present invention can refer to the description in the prior art and will not be repeated here.

[0131] Embodiment 2

[0132] The embodiment of the present invention also provides a reference Figure 5 In the optical communication transmission system shown, both the transmitting end and the receiving end of the optical communication transmission system are provided with the optical switching device 8 described in the first embodiment.

[0133] Here, the optical switching device at the transmitting end of the optical communication transmission system and the receiving end of the optical communication transmission system are respectively referred to as the transmitting end optical switching device and the receiving end optical switching device. The transmitting end optical switching device and the receiving end optical switching device are connected through a main path or a backup path. The transmitting end optical switching device and the receiving end optical switching device both include a transmitting port Tx, a receiving port Rx, a main path transmitting port T1, a backup path transmitting port T2, a main path receiving port R1 and a backup path receiving port R2. The main path transmitting port T1 of the transmitting end optical switching device is connected to the main path receiving port R1 of the receiving end optical switching device through the main path, and the backup path transmitting port T2 of the transmitting end optical switching device is connected to the backup path receiving port R2 of the receiving end optical switching device through the backup path. The main path receiving port R1 of the transmitting end optical switching device is connected to the main path transmitting port T1 of the receiving end optical switching device through the main path, and the backup path receiving port R2 of the transmitting end optical switching device is connected to the backup path transmitting port T2 of the receiving end optical switching device through the backup path.

[0134] The specific implementation of the optical communication transmission system provided in the embodiment of the present invention can refer to the detailed description of the optical switching device in the above embodiment, and the repeated parts will be omitted.

[0135] In an optional embodiment, when the distance between the transmitting end and the receiving end of the optical communication transmission system is relatively short, the optical switching device at the transmitting end and the optical switching device at the receiving end may not be connected to an optical amplifier. In this case, the optical communication transmission system is an optical communication transmission system without an optical amplifier. Figure 6 As shown, the optical switching device 8 connects the optical amplifier access ports a1 and b1, a2 and b2, c1 and d1, c2 and d2 through optical fibers, and the switching threshold is automatically adjusted and the fast switching mode remains unchanged.

[0136] In this case, since the optical amplifier is not connected, there is no need to consider the working mode of the optical amplifier, and the power change value is directly sent to the optical switching receiving unit at the receiving end. When the received signal optical power is less than the updated switching threshold, the second switching subunit of the optical switching receiving unit switches the line between the at least two groups of receiving lines. The main and standby line switching of the present invention is also not affected by the pump-off time of the optical amplifier, which greatly reduces the switching delay of the optical switching device 8 and can meet the switching delay requirements of more special services.

[0137] In this document, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The orientation or position relationship indicated by the terms "upper", "lower", etc. is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0138] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. The present invention is not limited to any single aspect, any single embodiment, or any combination and / or permutation of these aspects and / or embodiments. Each aspect and / or embodiment of the present invention can be used alone, or in combination with one or more other aspects and / or other embodiments.

[0139] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An optical switching device, characterized in that: include: An optical switching unit, an optical switching sending unit, an optical switching receiving unit and a control unit, wherein: The optical switching sending unit includes at least two groups of sending lines, and the optical switching receiving unit includes at least two groups of receiving lines; the optical switching unit includes a first switching subunit and a second switching subunit; The transmission line is used to monitor the power of each channel of the signal light of the transmission site, and when the power of the signal light of the transmission site changes, determine the corresponding power change value; The receiving circuit is used to adjust the switching threshold of the second switching subunit according to the power change value determined by the sending circuit to obtain an updated switching threshold; and detect the received signal optical power; The second switching subunit is used to perform line switching between the at least two groups of receiving lines when the received signal optical power is less than the updated switching threshold; The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site; and is also used to generate a switching command and send it to the first switching subunit of the sending site after the second switching subunit of the receiving site switches the at least two groups of receiving lines; The first switching subunit is used to perform line switching between the at least two groups of sending lines after receiving the switching command.

2. The optical switching device according to claim 1, characterized in that: The transmission line includes a power monitoring subunit, a first optical amplifier access port, a photoelectric detection subunit and a line transmission port connected in sequence; The transmission line further comprises an optical monitoring channel module, the transmission side of which is connected to the power monitoring subunit; The power monitoring subunit is used to monitor the power of each channel of the sending site signal light, divide the sending site signal light into a first optical signal and a first optical power monitoring signal, determine the power change value according to the first optical power monitoring signal and send it to the control unit; The control unit is used to determine whether to send the power change value to the optical switching receiving unit of the receiving site according to the working mode of the optical amplifier connected to the first optical amplifier access port; The optical monitoring channel module is used to send the power change value to the receiving line of the receiving site; The photoelectric detection subunit is used to generate a second optical signal and a first optical detection signal based on the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port, and send the second optical signal to the line sending port.

3. The optical switching device according to claim 2, characterized in that: The power monitoring subunit comprises a first wavelength division multiplexer, an optical attenuator and a first optical splitter connected in sequence; The power monitoring subunit further includes an optical channel monitoring module, and the optical channel monitoring module is connected to the output end of the first optical splitter; The first wavelength division multiplexer connects the transmitting side of the optical supervisory channel module and the first switching subunit; The first wavelength division multiplexer is used to couple the sending site signal light with the first optical monitoring signal of the optical monitoring channel module to generate a first combined optical signal; The optical attenuator is used to adjust the optical power of the first combined optical signal to obtain an attenuated signal; The first optical splitter is used to split the attenuated signal into a first optical signal and a first power monitoring signal according to a first preset ratio, and send the first optical signal to the optical amplifier connected to the first optical amplifier access port, and send the first power monitoring signal to the optical channel monitoring module.

4. The optical switching device according to claim 3, characterized in that: The photoelectric detection subunit includes a second spectrometer and a first photoelectric detector; The input end of the second optical splitter is connected to the first optical amplifier access port, and the output end of the second optical splitter is connected to the first photodetector and the line sending port; The second optical splitter is used to split the first optical signal amplified by the optical amplifier connected to the first optical amplifier access port into a second optical signal and a first optical detection signal according to a second preset ratio, and send the second optical signal to the line sending port, and send the first optical detection signal to the first photodetector.

5. The optical switching device according to claim 4, characterized in that: The receiving line includes a line receiving port, a third optical splitter, a second optical amplifier access port and a second wavelength division multiplexer connected in sequence; The receiving circuit and the sending circuit share the optical monitoring channel module; The receiving circuit further includes a second photodetector, and the second photodetector is connected to the output end of the third optical splitter; The output end of the second wavelength division multiplexer is connected to the receiving side of the optical supervisory channel module and the second switching subunit respectively; The third optical splitter is used to split the optical signal received by the line receiving port into a third optical signal and a second optical detection signal according to a third preset ratio, and send the third optical signal to the second optical amplifier access port, and send the second optical detection signal to the second photodetector; The second wavelength division multiplexer is used to divide the third optical signal amplified by the optical amplifier connected through the second optical amplifier access port into a second optical monitoring signal and a fourth optical signal, and send the second optical monitoring signal to the optical monitoring channel module, and send the fourth optical signal to the second switching subunit.

6. The optical switching device according to claim 5, characterized in that: The updated switching threshold is determined by the initial signal power P0 detected by the second photoelectric detector when the line project is opened, the line system margin β and the power change value Δ.

7. The optical switching device according to claim 5, characterized in that: The control unit is further used for: determining a line loss according to the first optical detection signal and the second optical detection signal; if the line losses of the main line and the backup line are inconsistent, determining a loss adjustment value according to the line losses of the main line and the backup line, and transmitting the loss adjustment value to an optical switching sending unit; The parameters of the optical attenuators of the at least two groups of transmission lines are adjusted according to the attenuation adjustment value, so that the line attenuations of the main line and the backup line are consistent.

8. The optical switching device according to claim 2, characterized in that: The working modes of the optical amplifier connected to the first optical amplifier access port include a constant gain mode and a constant power output mode; The control unit is used to control the optical monitoring channel module to send the power change value to the optical switching receiving unit of the receiving site if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant gain mode; if the working mode of the optical amplifier connected to the first optical amplifier access port is a constant power output mode, the power change value is not sent to the optical switching receiving unit of the receiving site.

9. The optical switching device according to claim 8, characterized in that: The first photoelectric detector is also used to detect the initial optical power when the line is connected and the optical power after the attenuation value of the optical attenuator is changed each time; The control unit is used to determine that the operating mode of the optical amplifier connected to the first optical amplifier access port is a constant gain mode if the optical power received after each change of the attenuation value of the optical attenuator is the sum of the initial optical power and the attenuation value; and to determine that the operating mode of the optical amplifier connected to the first optical amplifier access port is a constant output power mode if the optical power received after each change of the attenuation value of the optical attenuator remains unchanged.

10. An optical communication transmission system, characterized in that: The transmitting end of the optical communication transmission system and the receiving end of the optical communication transmission system are both provided with the optical switching device as described in any one of claims 1-9.

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