Optical communication network

Abstract

Provided is an optical communication network, which relates to the field of optical communications, and can reduce the time taken for replacing dummy light with signal light in a link. The optical communication network comprises at least three WSSs, wherein the WSSs each comprise a common port and a plurality of branch ports; a first branch port of a first WSS is connected to a first branch port of a second WSS; a second branch port of the first WSS is connected to a first branch port of a third WSS; a common port of the first WSS is used for receiving a first optical signal and outputting the first optical signal to the second WSS; the first WSS is further used for receiving a first control instruction issued by a network control apparatus and outputting, on the basis of the first control instruction, the first optical signal to the third WSS; the third WSS is used for receiving, before the first WSS outputs the first optical signal to the third WSS, a second control instruction issued by the network control apparatus; and the third WSS is further used for outputting, after the first optical signal is received, the first optical signal to a common port of the third WSS in response to the second control instruction. The embodiments of the present application are applied to optical communications.

Description

An optical communication network

[0001] The present application claims priority from the Chinese patent application No. 202410446655.5 filed on April 12, 2024, and entitled "An optical communication network", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of optical communications, and in particular, to an optical communication network. BACKGROUND

[0003] With the development of transmission related technologies, the requirements for the transmission capacity and the transmission quality (also referred to as transmission performance) of a transmission network are increasingly high; wherein the transmission capacity includes the transmission bandwidth and the transmission capacity. For example, an optical communication network is based on the principle of wavelength division multiplexing (WDM), and through using optical signals with different wavelengths as carriers of service data (or transmission information), the transmission capacity (especially the transmission capacity) is improved.

[0004] In order to continuously improve the transmission capacity, the wavelength range of the optical signals transmitted by the optical communication network evolves from the conventional (C) band with generally shorter wavelengths and narrower wavelength range to the conventional and long wavelength (C+L) band with generally longer wavelengths and wider wavelength range. However, the increase of the wavelength range will result in more obvious interaction between optical signals of different wavelengths. For example, during the transmission of the optical signals along the optical fiber, there is a stimulated raman scattering (SRS) effect. The SRS effect causes the energy (i.e., optical power) of the optical signals of short wavelengths to transfer to the optical signals of long wavelengths, resulting in the difference in the optical power of the optical signals of different bands and thus affecting the transmission quality of the optical signals of the full band. Generally, in order to suppress the impact of the SRS effect on the transmission quality, a power pre-tilt scheme (i.e., increasing the optical power of the optical signals of short wavelengths and reducing the optical power of the optical signals of long wavelengths) can be used to ensure the power flatness of the optical signals after transmission. Specifically, when the channels of the C+L system (transmitting optical signals of the C+L band) are not in full wave state, the power transfer between different channels will become very complex. In order to solve this problem, a dummy optical signal (also referred to as dummy light, i.e., an optical signal of a wavelength corresponding to the channel without carrying service data) can be filled into the channel (corresponding to a wavelength or a wavelength range) in the idle state, so that the optical signals transmitted by the optical communication network are in the full wave state of the C+L band, to ensure the transmission performance of the optical communication network. Generally, the filling of the dummy light can be realized by a wavelength selective switch (WSS) deployed on the link of the optical communication network; one branch of the WSS can be connected to an amplifier self emission (ASE) light source as a dummy light source. In this way, when the transmitted optical signals do not include some band optical signals, the LCOS module (also referred to as liquid crystal on silicon, LCOS) in the WSS can fill the dummy light of the band output by the dummy light source into the corresponding channel, so that the optical signals transmitted in the link of the optical communication network are always in the full wave state.

[0005] However, in some scenarios of the optical communication network, it is necessary to replace the dummy light in the optical signals transmitted in the link with signal light (also referred to as real light) (or replace the signal light with the dummy light). Generally, the above-mentioned replacement process takes a long time, which will affect the transmission quality of the optical signals of other bands. SUMMARY

[0006] The application provides an optical communication network, by controlling a plurality of WSSs in different links of the optical communication network, time consumption for replacing between false light and signal light in the link is reduced, so that optical power in the link does not decrease greatly, thereby keeping transmission quality of the optical signal stable.

[0007] In a first aspect, an optical communication network is provided. The optical communication network comprises: at least three WSSs, each of which comprises a common end and a plurality of branch ends; a first branch end of a first WSS among the at least three WSSs is connected to a first branch end of a second WSS among the at least three WSSs; a second branch end of the first WSS is connected to a first branch end of a third WSS among the at least three WSSs; wherein the common end of the first WSS is configured to receive a first optical signal and output the first optical signal to the second WSS; the first WSS is further configured to receive a first control instruction issued by a network control device and switch to output the first optical signal to the third WSS based on the first control instruction; the third WSS is configured to receive a second control instruction issued by the network control device before the first WSS switches to output the first optical signal to the third WSS; and the third WSS is further configured to switch to output the first optical signal to the common end of the third WSS in response to the second control instruction after receiving the first optical signal.

[0008] So, one WSS (i.e., the first WSS) in the optical communication network described above is connected with the other two WSSs (i.e., the second WSS and the third WSS) through two branch ends (i.e., the first branch end and the second branch end). In terms of function, the first WSS can receive an optical signal (true light, i.e., the first optical signal) through the common end and output the first optical signal to the first branch end of the second WSS. The first WSS can also receive a control instruction (i.e., the first control instruction) issued by the network control device and switch to output the optical signal to the third WSS based on the first control instruction. Before the first WSS switches to output the first optical signal to the third WSS, the third WSS can receive a control instruction (the second control instruction) issued by the network control device. Further, after the third WSS receives the first optical signal output by the first WSS, it can switch to output the received first optical signal to the common end of the third WSS in response to the third control instruction. Optionally, on a certain link in the optical communication network, there can be multiple first WSSs and multiple second WSSs; or on a certain link in the optical communication network, there can also be multiple third WSSs. Among them, the first WSS and the second WSS are usually deployed on the same communication link (for example, it can be a working link, also known as a main link or an original link) in the optical communication network, and the third WSS is usually deployed on another communication link (for example, it can be a protection link, also known as a backup link or a new link) in the optical communication network. In this way, the first WSS usually outputs the optical signal (true light) received by the common end to the second WSS. It is not difficult to understand that the above-mentioned three WSSs are usually deployed at the same transmission node position in the optical communication network, for example, in the same machine room. In this way, the original link and the new link pass through the same transmission node, so the first WSS, the second WSS and the third WSS can also be considered to be deployed on the same link. However, in scenarios such as transmission failure of the original link, service transmission needs to be rerouted (redetermine the transmission path), the optical communication network needs to be expanded (increase the transmission capacity of the optical communication network, for example, add more wavelengths of optical signals as carriers of service data), etc., a certain transmission node on the original link needs to be added or removed (add or remove wavelengths (of optical signals) used to carry service data) and the transmitted signal light is transmitted to the new link (i.e., switched), to ensure the normal transmission of services, i.e., the first WSS needs to switch between true light and false light and output the first optical signal received by the common end to the third WSS. Usually, WSS needs to perform corresponding calculation to realize the corresponding switching (such as switching the branch end of the optical signal output), determine the phase pattern corresponding to the switching of the LCOS, load it to the LCOS, so that the optical signal can be output according to the corresponding branch end.By the above scheme, before the first WSS switches to output the first optical signal to the third WSS, the third WSS has already received the third control instruction issued by the network control device, and thus calculates the phase map corresponding to the switching according to the received third control instruction. In this way, when the first WSS in the original link completes the switching, the third WSS receives the first optical signal output by the first WSS, and will switch to output the received first optical signal to the common end according to the pre-calculated phase map. Based on the above scheme, by controlling the multiple WSSs in different links in the optical communication network, the WSS in the new link does not need to wait for the WSS in the original link to complete the switching, but starts to calculate the phase map at the same time as the WSS in the original link switches. In this way, the time consumption for completing the replacement between the dummy light and the signal light in the link can be reduced, so that the optical power in the link does not decrease significantly, thereby keeping the transmission quality of the optical signal stable. Further, the time consumption for completing the switching between the links can also be reduced, the efficiency of the switching between the links is improved, and the fast switching of the optical signal transmission from the original link to the new link is realized.

[0009] In a possible implementation, the optical communication network further includes: a first dummy light output module, wherein the first dummy light output module is connected to the second branch end of the third WSS; the second branch end of the third WSS is used to receive a second optical signal output by the first dummy light output module, and output the second optical signal to the common end of the third WSS; and the switching to output the first optical signal to the common end of the third WSS in response to the second control instruction includes: gradually increasing the optical power of the first optical signal output to the common end of the third WSS, and gradually decreasing the optical power of the second optical signal output to the common end of the third WSS.

[0010] So, in the above scheme, the two branch ends (i.e., the first branch end and the second branch end) of the WSS (i.e., the third WSS) on a certain link in the optical communication network are connected with the WSS (i.e., the first WSS) on another link and the false light output module (i.e., the first false light output module), respectively. Specifically, the third WSS can receive the true light (i.e., the first optical signal) output by the first WSS on another link through one branch end, and receive the false light (i.e., the second optical signal) output by the first false light output module through the other branch end, and output through the common end. Further, when the third WSS switches the true light and the false light according to the received control instruction (i.e., the second control instruction), it can be realized by gradually increasing the optical power of the true light output to the common end and gradually reducing the optical power of the false light output to the common end. In this way, the above scheme connects the false light output device to the branch end of the third WSS on the new link in the optical communication network, so that the WSS can gradually reduce the proportion of the optical power of the false light in the optical power of the optical signal output by the common end and gradually increase the proportion of the optical power of the true light when switching the true light and the false light, so that the optical power of the optical signal transmitted in the link can be kept stable. In this way, the above scheme can ensure that the optical power of the entire band of the optical signal transmitted in the link does not drop during the switching process of the true light and the false light, thereby realizing smooth switching of the true light and the false light.

[0011] In a possible implementation, the optical communication network further includes: a second false light output module, wherein the second false light output module is connected to the second branch end of the second WSS; the second branch end of the second WSS is used to receive a third optical signal output by the second false light output module; and the second WSS is further used to receive a third control instruction issued by the network control device and switch to output the third optical signal to the common end of the second WSS in response to the third control instruction.

[0012] So, in the above scheme, the two branch ends (i.e., the first branch end and the second branch end) of the WSS (i.e., the second WSS) on a certain link in the optical communication network are connected with another WSS (i.e., the first WSS) on the link and a false optical output module (i.e., the second false optical output module), respectively. Specifically, the second WSS can receive the true light (i.e., the first optical signal) output by the first WSS on the link through one branch end and the false light (i.e., the third optical signal) output by the second false optical output module through the other branch end, and output through the common end. Generally, the second WSS receives the first optical signal output by the first WSS and outputs to the common end. In the above other schemes, the first WSS deployed on the same link as the second WSS can switch to output the true light (i.e., the first optical signal) to the third WSS on another link in response to the received control instruction. In this way, when the switchover from the original link to the new link is needed, in order to ensure that other links related to the original link can be normally transmitted, the second WSS in the original link needs to be switched between the true light and the false light, so that the original link can still continue to transmit the optical signal (which is the false light). Based on the above scheme, the second WSS can receive the control instruction (the third control instruction) issued by the network control device. Further, the second WSS can switch to output the third optical signal to the common end of the second WSS according to the received third control instruction, that is, the second WSS completes the switching between the true light and the false light, and the common end of the second WSS only outputs the false light. In this way, through the above scheme, when the switchover between the links is needed, the second WSS on the original link can be controlled to switch between the true light and the false light through the third control instruction, so as to ensure that other links related to the original link can be normally transmitted. Further, in the process of the second WSS switching between the true light and the false light (i.e., the second WSS has not completed the switching between the true light and the false light), the first control instruction can also be issued to the first WSS on the original link. In this way, when the second WSS completes the switching between the true light and the false light, the first WSS can quickly respond to switch the branch end of the output (true light). Of course, in other examples, when the switchover between the links is needed, the first control instruction can also be issued to the first WSS at the same time as the third control instruction is issued to the second WSS, and the embodiments of the present application do not limit this. So, the above scheme can control the second WSS in the original link to switch between the true light and the false light, so that the false light can be normally transmitted in the original link, thereby reducing the influence of the switching of any WSS on the transmission quality of the link.

[0013] In a possible implementation, in response to the third control instruction switching to output the third optical signal to the common end of the second WSS, the method comprises gradually increasing the optical power of the third optical signal output to the common end of the second WSS, and gradually decreasing the optical power of the first optical signal output to the common end of the second WSS.

[0014] Then, in the above scheme, when the WSS (i.e., the second WSS) on a certain link in the optical communication network performs the switching of the true light and the false light according to the received control instruction (the third control instruction), the switching of the true light and the false light can be realized by gradually increasing the optical power of the false light output to the common end and gradually reducing the optical power of the true light reduced to the common end. In this way, based on the above scheme, the second WSS can gradually reduce the proportion of the optical power of the true light in the optical power of the optical signal output by the common end through the false light output device connected by the branch end, and gradually increase the proportion of the optical power of the false light, so as to ensure that the optical power of the entire wavelength band of the optical signal in the link does not drop during the switching process, and can remain stable to ensure that the original link can continue to transmit normally.

[0015] In a possible implementation, the optical communication network further includes: a fourth WSS and a fifth WSS; the common end of the fourth WSS is connected to the common end of the third WSS, and the first branch end of the fourth WSS is connected to the first branch end of the fifth WSS; the fourth WSS is further configured to receive a fourth control instruction issued by the network control device, and transmit the second optical signal to the fifth WSS in response to the fourth control instruction.

[0016] Then, in the above scheme, the optical communication network further comprises a WSS (i.e., a fourth WSS) connected with the common end of the third WSS, and another WSS (i.e., a fifth WSS) connected with the branch end of the fourth WSS, wherein the third WSS, the fourth WSS and the fifth WSS are usually deployed on the same link (usually a new link). Generally, the common end of the fourth WSS can receive the optical signal (i.e., the second optical signal) output by the common end of the third WSS. Based on the above other schemes, when the first WSS receives the first control instruction issued by the network control device, it will start to switch the true light output to the branch end of the third WSS. For example, gradually reduce the optical power of the true light output by the first branch end of the first WSS to the second WSS, and gradually increase the optical power of the true light output by the second branch end of the first WSS. Based on the above process, when the first WSS has not completed the switching (switching the true light to the third WSS), through the above scheme, the fourth WSS can also receive the control instruction (i.e., the fourth control instruction) issued by the network control device, and based on the received control instruction, transmit the second optical signal received from the third WSS to the fifth WSS. In this way, before the first WSS deployed in a node starts to switch but has not yet output the true light to the third WSS in the new link, the fourth WSS deployed in another node can transmit the received false light to the fifth WSS according to the received control instruction, so that the false light can be normally transmitted in the new link. In this way, before the switching between the two links is completed, the new link can be normally transmitted through the two WSSs deployed in another node, ensuring the smoothness of the new link. Further, when the first WSS completes the switching, the true light transmitted to the third WSS can be normally transmitted in the new link through the fourth WSS and the fifth WSS.

[0017] In a possible implementation, the network control device is further configured to: determine that the transmission quality of the first signal light does not satisfy the threshold; and issue the first control instruction to the first WSS.

[0018] Then, in the above scheme, the network control device in the optical communication network can detect the transmission quality of the first optical signal transmitted by the link, and when it is determined that the transmission quality of the first signal light does not meet the threshold, the first control instruction is issued to the first WSS. In a possible implementation manner, the network control device detects the optical power of the first optical signal, and by determining that the optical power of the first signal light does not meet the optical power threshold of the link, it can be determined that the transmission quality of the link is poor; the network control device will send the first control instruction to the first WSS. Further, when the first WSS receives the first control instruction issued by the network control device, it will start switching the branch end of the output true light to switch to the third WSS on another link through another branch end to output the first optical signal. It is not difficult to understand that the above is only one possible scenario of switching the WSS in the optical communication network, and in other scenarios, the WSS can also be switched similarly. For example, in the scenario of service transmission in the optical communication network requiring rerouting or expansion, that is, when a certain transmission node on the link needs to be added to the wave operation, the optical communication network can also realize the corresponding switching of the WSS by other corresponding configurations. Then, through the above scheme, the network control device in the optical communication network can detect the optical signal transmitted by the link, determine the transmission quality of the link, and then control the WSS to switch accordingly by issuing a control instruction.

[0019] In a possible implementation manner, the wavelength range of the first optical signal satisfies: 1530 nanometers to 1565 nanometers.

[0020] Therefore, in the above scheme, the wavelength range of the true light carrying service data transmitted in the optical communication network is 1530 nm to 1565 nm, that is, the first optical signal is a C-band optical signal. In a possible implementation, the original link of the optical communication network transmitting the C-band optical signal fails, and switching between links is needed to switch the optical signal to a new link for transmission. Generally, one or more optical amplifiers are deployed on the link between nodes in the optical communication network to amplify the optical signal during transmission, thereby corresponding to the loss of the optical signal during transmission to ensure the transmission quality of the optical signal. When switching between links, the optical amplifier in the new link needs to be switched from an inactive state to an active state. In this way, in the optical communication network transmitting the C-band optical signal, the switching time from the failure of the original link to the switching to the new link includes: the switching time of the WSS, and the response time of the optical amplifier from no light (inactive state) to light (active state) after the switching between links is completed. However, since the optical amplifier in the new link is always in an inactive state (no optical signal is transmitted), and the optical amplifier needs to reach a certain threshold value before it starts to respond. Therefore, the response time of the optical amplifier is relatively long. Based on the above other schemes, the switching of the first WSS (that is, the switching of the branch end of the true light output) is realized by loading a phase diagram on the LCOS. In this way, through the control instruction issued by the network control device, the phase diagram loaded on the LCOS in the first WSS can be configured, so that the optical power of the optical signal in the link can quickly reach the threshold value of the optical amplifier, and the optical amplifier can start to respond before the switching of the first WSS is completed. Therefore, when the optical communication network transmits the C-band optical signal, based on the above other schemes, the response time of the optical amplifier can be reduced, the fast switching between links of the C-band optical signal can be realized, and the switching rate between links is improved.

[0021] In a possible implementation, the wavelength range of the first optical signal satisfies 1530 nm to 1625 nm.

[0022] Therefore, in the above scheme, the wavelength range of the true light carrying service data transmitted in the optical communication network is 1530 nm to 1625 nm, that is, the first optical signal is a C-band optical signal. In a possible implementation, the wavelength range of the first optical signal satisfies 1530 nm to 1625 nm.

[0023] In a possible implementation, one or more of the first false light output module and the second false light output module include an amplified spontaneous emission (ASE) light source.

[0024] The technical effects brought by any design of the first aspect can refer to the technical effects of the design in the first aspect as described above, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of a WSS provided in an embodiment of the present application;

[0026] FIG2 is a schematic diagram of an LCOS module provided in an embodiment of the present application;

[0027] FIG3 is a schematic diagram of a switching method provided in an embodiment of the present application;

[0028] FIG4 is a schematic diagram of a switching method provided in another embodiment of the present application;

[0029] FIG5 is a schematic diagram of an optical communication network provided in an embodiment of the present application;

[0030] FIG6 is a schematic diagram of an optical communication network provided in another embodiment of the present application;

[0031] FIG7 is a schematic diagram of a switching time provided in an embodiment of the present application;

[0032] FIG8 is a schematic diagram of a switching process provided in an embodiment of the present application;

[0033] FIG9 is a schematic diagram of an optical communication network provided in accordance with another embodiment of the present application;

[0034] FIG10 is a schematic diagram of an optical communication network provided in accordance with yet another embodiment of the present application;

[0035] FIG11 is a schematic diagram of an optical power variation provided in an embodiment of the present application;

[0036] FIG12 is a schematic diagram of a phase diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] This application will present various aspects, embodiments, or features in the context of systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in conjunction with the figures. Furthermore, combinations of these aspects may also be used.

[0038] It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being more preferred or advantageous than other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0039] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0040] With the development of transmission related technologies, the requirements for the transmission capacity and the transmission quality (or transmission performance) of a transmission network are increasingly high, wherein the transmission capacity includes the transmission bandwidth and the transmission capacity. For example, an optical communication network is based on the WDM principle, and the transmission capacity (especially the transmission capacity) is improved by using optical signals with different wavelengths as carriers of service data (or transmission information).

[0041] In order to continuously improve the transmission capacity, the wavelength range of the optical signals transmitted by the optical communication network is evolved from the C band with generally shorter wavelengths and a narrower wavelength range to the C+L band with generally longer wavelengths and a wider wavelength range. However, the increase of the wavelength range will result in more obvious interaction between optical signals with different wavelengths. For example, during the transmission of the optical signals along the optical fiber, there is a stimulated Raman scattering (SRS) effect. The SRS effect causes the energy (i.e., optical power) of the optical signals with shorter wavelengths to transfer to the optical signals with longer wavelengths, resulting in a difference in the optical power of the optical signals of different bands, thereby affecting the transmission quality of the optical signals of the full band. Generally, in order to suppress the influence of the SRS effect on the transmission quality, a power pre-tilt scheme (i.e., increasing the optical power of the optical signals with shorter wavelengths and reducing the optical power of the optical signals with longer wavelengths) can be used to ensure the power flatness of the optical signals after transmission. Specifically, a dummy optical signal (also referred to as a dummy light, i.e., an optical signal with a wavelength corresponding to a channel that does not carry service data) can be filled into a channel (corresponding to a wavelength or a wavelength range) in an idle state, so that the optical signals transmitted by the optical communication network are in a full-wave state in the C+L band, thereby ensuring the transmission performance of the transmission network.

[0042] Generally, the filling of the dummy light is mainly realized by a WSS. For example, referring to FIG. 1, an embodiment of the present application provides a schematic diagram of a WSS. For ease of description, in the following embodiments of the present application, the WSS is identified as WSS 10. As shown in FIG. 1, the WSS 10 includes one common end (common end 101 in FIG. 1) and two branch ends (branch end 102 and branch end 103 in FIG. 1).

[0043] It is not difficult to understand that, for ease of description, only the WSS shown in FIG. 1 is taken as an example here, and the internal structure and the internal components of the WSS should not be limited by this. For example, the WSS can also include more branch ends.

[0044] Specifically, in the first direction, the branch end 102 of the WSS 10 is configured to receive the real light, and the other branch end 103 of the WSS is configured to receive the dummy light. The common end 101 of the WSS 10 is configured to output the real light received by the branch end 102 of the WSS and output the dummy light received by the branch end 103 of the WSS, i.e., the multiplexing function of the WSS. For example, when some wavelength bands (of the light signal) are not included in the real light received by the branch end 102 of the WSS 10, the dummy light of the wavelength bands can be filled into the corresponding channels by the LCOS module in the WSS, so that the light signal output by the common end 101 is in the full-wave state.

[0045] It can be understood that, in the other direction opposite to the first direction, the common end 101 of the WSS 10 is configured to receive the real light or the dummy light; the branch end 102 of the WSS 10 is configured to output the real light received by the common end 101, and the other branch end 103 of the WSS is configured to output the dummy light received by the common end 101, i.e., the demultiplexing function of the WSS.

[0046] Of course, the common end or the branch end of the WSS can be configured as the input end of the light signal (including the real light and the dummy light) or the output end of the light signal (including the real light and the dummy light), i.e., the common end or the branch end of the WSS is the input and output end, and the light signal can be transmitted.

[0047] In this way, when some wavelength bands of the light signal transmitted in the optical communication network are not included, the dummy light of the wavelength bands output by the dummy light source can be filled into the corresponding channels by the LCOS module in the WSS, so that the light signal transmitted in the optical communication network is always in the full-wave state.

[0048] For example, referring to FIG. 2, the embodiment of the present application provides a schematic diagram of an LCOS module. As shown in (1) of FIG. 2, the LCOS module includes a glass layer (labeled as glass layer 201 in (1) of FIG. 2), an indium tin oxide (ITO) electrode (labeled as ITO electrode 202 in (1) of FIG. 2), a liquid crystal layer (labeled as liquid crystal layer 203 in (1) of FIG. 2), an aluminum-coated electrode (labeled as aluminum-coated electrode 204 in (1) of FIG. 2), and a substrate (labeled as substrate 205 in (1) of FIG. 2).

[0049] For ease of illustration, only the LCOS module shown in (1) of FIG. 2 is taken as an example herein, and should not constitute a limitation on the specific material and specific structure of the LCOS module. In a possible implementation, the LCOS module can further include a polarizing beam splitter (PBS) disposed above the glass layer 201, for polarizing the incident light. For example, the substrate 205 described above can be implemented by a complementary metal oxide semiconductor (CMOS).

[0050] Specifically, in combination with (1) of FIG. 2, the incident light will be incident to a certain position on the upper surface of the glass layer 201 of the LCOS module, and then transmitted to the aluminum-coated electrode 204 through the glass layer 201, the ITO electrode 202 and the liquid crystal layer 203 in sequence. The aluminum-coated electrode 204 can reflect the incident light, and the generated (or determined) outgoing light after reflection. The outgoing light is transmitted to the glass layer 201 through the liquid crystal layer 203 and the ITO electrode 202 in sequence, and exits from a certain position on the upper surface of the glass layer 201 at a certain angle.

[0051] Generally, the LCOS module in the WSS can load a phase diagram, thereby realizing the function of wavelength division or wavelength combination of the WSS. For example, referring to (2) of FIG. 2, a possible phase diagram is shown. In combination with (2) of FIG. 2, the abscissa represents the position, i.e., the position of the incident light transmitted to the aluminum-coated electrode 204 through the glass layer 201, the ITO electrode 202 and the liquid crystal layer 203 in sequence; and the ordinate represents the voltage value required for the aluminum-coated electrode 204 to realize phase modulation on the incident light.

[0052] Based on the above description, the LCOS module can set the voltage at the corresponding position on the aluminum-coated electrode 204 by loading the phase diagram, thereby realizing a corresponding degree of phase modulation on the incident light incident to the corresponding position on the aluminum-coated electrode 204, generating (or determining) the outgoing light, and finally exiting from the LCOS module at a certain angle. Further, the outgoing light will finally be transmitted to the branch end or the common end of the WSS at a corresponding angle, and output through the branch end or the common end, thereby realizing the function of wavelength division or wavelength combination of the WSS.

[0053] However, in the optical communication system in which the transmitted optical signal is a full-wave optical signal in the C+L wave band, when a certain node needs to perform drop operation due to the needs of re-routing, expansion, etc., and needs to replace the dummy light in the transmitted optical signal with signal light (also referred to as real light) (or replace the signal light with dummy light), the optical power of the optical signal in the wave band to be replaced will drop (decrease significantly) during the replacement process, and at the same time, the transmission quality of the optical signal in other wave bands will also be affected.

[0054] Based on the above problems, a batch switching mode can generally be adopted. For example, referring to FIG. 3, an embodiment of the present application provides a schematic diagram of a switching mode, showing a process of replacing false light with true light in batches. In this embodiment, a plurality of batches are used to replace false light including a plurality of different wavelengths (blank squares in FIG. 3) with true light (hatched squares in FIG. 3), and each batch replaces false light of a part of the wavelengths with true light.

[0055] Based on the WSS 10 shown in FIG. 1, specifically, in combination with FIG. 3, when it is necessary to replace false light including 36 different wavelengths output by the common end 101 of the WSS 10 with true light, the replacement can be divided into 6 batches, and each batch replaces false light of 6 wavelengths with true light. Finally, false light of 36 wavelengths output by the common end 101 of the WSS 10 is completely replaced with true light.

[0056] It is not difficult to understand that, for the convenience of description, only the switching mode shown in FIG. 3 is taken as an example herein, and the number of wavelengths, the size of the wavelengths, and the like should not be limited by this example. In a possible implementation, the switching mode can be used to replace true light with false light. In other examples, there can be more false light of different wavelengths that needs to be replaced with true light. For example, more batches can be used to replace false light with true light.

[0057] Then, by adopting the batch switching mode, a small amount of light signals can be replaced in batches, avoiding a large range of wavelength (channel) light power drop, and reducing the impact on the transmission quality of the optical communication network. However, the batch switching mode has a limited number of wavelengths to be switched each time, i.e., only a part (a small amount) of light signals of the wavelengths can be replaced in each batch. As a result, the optical communication network needs to issue switching instructions to the WSS multiple times, and the LCOS needs to load the phase map multiple times, in order to finally complete the switching. In addition, the above scheme needs to be performed in series between the nodes of the optical communication network (i.e., after a node completes switching, another node can start switching), resulting in a long switching time, which seriously affects the efficiency of the link switching.

[0058] Based on the above problems, in order to improve the switching speed between links, a true-false light smooth switching technology is generally adopted. For example, referring to FIG. 4, an embodiment of the present application provides a schematic diagram of a switching mode. In combination with FIG. 4, the abscissa represents time; the ordinate represents the optical power of the light signal, and the solid curve represents the change (gradual decrease) of the optical power of the false light, and the dashed curve represents the change (gradual increase) of the optical power of the true light.

[0059] Based on the WSS 10 shown in FIG. 1, one branch end 102 of the WSS 10 is connected to the true light, and the other branch end 103 is connected to the false light. Specifically, in combination with FIG. 4, when the WSS 10 switches the false light and the false light, the optical power of the false light output by the common end 101 is reduced, and the optical power of the true light output by the common end 101 is increased, that is, the proportion of the false light in the optical signal output by the common end 101 is reduced, and the proportion of the true light is increased. In this way, it can be ensured that the optical power of the optical signal output by the common end 101 will not decrease significantly during the switching process, thereby reducing the impact on the optical communication network.

[0060] It is not difficult to understand that, for the sake of illustration, only the switching mode shown in FIG. 4 is taken as an example here, and the number of wavelengths, the size of the wavelength, etc. should not be limited by this. In one possible implementation, the true light can be replaced by the false light through the switching mode.

[0061] Then, through the above scheme, true and false light smooth switching can be achieved, and different wavelengths of false light can be switched together, which can greatly reduce the switching time and improve the switching speed.

[0062] Of course, the above-mentioned switching process is not strictly absolute smooth. For example, in combination with FIG. 4, when the proportion of the false light and the proportion of the true light are the same (i.e. each half), the optical power of the common end still has a certain degree of drop, that is, power jitter.

[0063] For example, referring to FIG. 5, the embodiment of the present application provides a schematic diagram of an optical communication network, which shows the process of realizing link switching through the above scheme. For the sake of illustration, in the following embodiments of the present application, the optical communication network is identified as optical communication network 50. In combination with FIG. 5, the optical communication network 50 includes: two nodes (node A and node B in FIG. 5), any node includes two groups of WSS, and any WSS includes a common end and two branch ends; and four false light output devices (DL 505-1, DL 505-2, DL 505-3 and DL 505-4 in FIG. 5). Among them, node A includes WSS 501-1, WSS 501-2 and WSS 502-1, WSS 502-2. Node B includes WSS 503-1, WSS 503-2 and WSS 504-1, WSS 504-2.

[0064] Optionally, the WSS 501-1, the WSS 501-2, the WSS 503-1 and the WSS 503-2 are deployed on the original link, and the WSS 502-1, the WSS 502-2, the WSS 504-1 and the WSS 504-2 are deployed on the new link. It is understood that, for the convenience of illustration, only the switching mode shown in FIG. 5 is taken as an example herein, and the specific structure of the optical communication network, the number of included devices, the type of devices and the like should not be limited. In a possible implementation, the optical communication network described above further includes more nodes and more WSSs.

[0065] Specifically, in combination with FIG. 5, in the original link: one branch end of the WSS 501-1 is used to connect one branch end of the WSS 501-2, the other branch end of the WSS 501-1 is used to connect one branch end of the WSS 502-2, the other branch end of the WSS 501-2 is used to connect the DL 505-1, and the common end of the WSS 501-2 is used to connect the common end of the WSS 503-1. One branch end of the WSS 503-1 is used to connect one branch end of the WSS 503-2, and the other branch end of the WSS 503-2 is used to connect the DL 505-3. In the new link: the other branch end of the WSS 502-2 is used to connect the DL 505-2, and the common end of the WSS 502-2 is used to connect the common end of the WSS 504-1. One branch end of the WSS 504-1 is used to connect one branch end of the WSS 504-2, and the other branch end of the WSS 504-2 is used to connect the DL 505-4.

[0066] In combination with FIG. 5, the optical signal for service transmission is generally transmitted through the original link (i.e. in the normal state). In order to reduce the influence of the SRS effect, the channels corresponding to the wavelengths other than the true light in the C+L band are filled with false light of the corresponding wavelength, so as to ensure that the optical signal transmitted in the original link is always in the state of full wave of the C+L band.

[0067] It is understood that the new link generally transmits false light (i.e. in the normal state) to maintain the unobstructedness of the link. Specifically, the WSS 502-1 blocks the false light, and the WSS 502-2 transmits the false light received from the DL 505-2 to the WSS 504-1 through the common end. The WSS 504-1 blocks the false light, and the WSS 504-2 transmits the false light received from the DL 505-4 to another WSS connected thereto through the common end.

[0068] When the original link fails, it is necessary to switch from the original link to the new link, that is, to switch the true light to the new link for transmission. Specifically, in combination with FIG. 5, the switching process includes:

[0069] (1) At the WSS 501-2 in the original link, true light and false light switching is performed. In combination with FIG. 5, the optical power of the true light output from the WSS 501-1 to the WSS 501-2 is reduced, and the optical power of the true light output from the WSS 501-1 to the WSS 502-2 is increased. In this way, the true light will eventually be all transmitted to one branch end of the WSS 502-2, and the optical power of the true light transmitted to the WSS 501-2 will be reduced to 0. Further, the false light output from the DL 505-1 connected with the WSS 501-2 fills the channels of the part of the true light, so that the original link can continue to transmit, and the transmitted optical signal is false light.

[0070] (2) At the WSS 502-2 in the new link, the false light is output to the other branch end of the WSS 502-2 by the DL 505-2 connected with the WSS 502-2.

[0071] (3) At the WSS 502-2 in the new link, true and false light smooth switching is performed, and the true light will continue to transmit in the new link. Further, the WSS 502-2 can replace the channels corresponding to the wavelengths included in the true light (in the false light received from the DL 505-2, for example, including C+L band full waves) with the true light to ensure that the optical signal transmitted in the new link is in the state of C+L band full waves. The process of the WSS 502-2 performing true and false light smooth switching can refer to FIG. 4, which will not be described here.

[0072] Then, by the above steps, the switching from the original link to the new link can be realized, and the true light is switched to the new link to continue to transmit. However, the above process needs to perform true and false light smooth switching (for example, the WSS 502-2), that is, gradually reducing the optical power of the false light and gradually increasing the optical power of the true light. Therefore, it is necessary to ensure that the true light and the false light are connected to the WSS at the same time. In addition, the three steps in the above scheme need to be performed in sequence, resulting in a long time consumption for switching between links.

[0073] Based on the above problems, for example, referring to FIG. 6, an embodiment of the present application provides a schematic diagram of an optical communication network. For ease of description, in the following embodiments of the present application, the optical communication network is identified as optical communication network 60. In combination with FIG. 6, the optical communication network 60 includes at least three WSSs (WSS 601, WSS 602 and WSS 603 in FIG. 6), and any WSS includes one common end and multiple branch ends.

[0074] Generally, the three WSSs are deployed at the same transmission node position in the optical communication network, for example, in the same machine room. Among them, the WSS 601 and the WSS 602 are deployed on the same communication link (i.e. the original link) in the optical communication network, and the WSS 603 is deployed on another communication link (i.e. the new link) in the optical communication network.

[0075] It is not difficult to understand that, for the sake of illustration, only the optical communication network shown in FIG. 6 is taken as an example here, and the specific structure of the optical communication network, the number of included devices, the type of devices, etc. should not be limited. In a possible implementation, the optical communication network further includes more nodes and more WSSs. Optionally, the dummy light output device can be an ASE light source.

[0076] Specifically, in combination with FIG. 6, one branch end of the WSS 601 is connected to one branch end of the WSS 602, and the other branch end of the WSS 601 is connected to one branch end of the WSS 603.

[0077] Generally, the optical signal (i.e. real light) for service transmission is transmitted through the original link. That is, the common end of the WSS 601 receives the real light (identified as the first optical signal) and outputs the first optical signal to the WSS 602.

[0078] When the original link fails, it is necessary to switch from the original link to the new link, that is, to switch the real light to be transmitted in the new link. Specifically, in combination with FIG. 6, the switching process includes:

[0079] When the original link fails, the WSS 601 receives the control instruction (identified as the first control instruction) issued by the network control device (not shown in FIG. 6) and switches to output the first optical signal to the WSS 603 based on the first control instruction. Before the WSS 601 switches to output the first optical signal to the WSS 603, the WSS 603 can receive the control instruction (identified as the second control instruction) issued by the network control device. In this way, after the WSS 603 receives the first optical signal, it can switch to output the first optical signal to the common end of the WSS 603 in response to the received second control instruction, that is, the first optical signal will continue to be transmitted in the new link.

[0080] It should be noted that the above process is only an example of a possible switching process between links when the original link fails. For example, the failure can be a transmission failure between the WSS 601 and the WSS 602 deployed in the same node.

[0081] Generally, the WSS implements the corresponding switching (e.g. switching the branch end of the optical signal output), and the WSS needs to perform corresponding calculation to determine the phase map corresponding to the switching (refer to FIG. 2) and load the phase map to the LCOS. In this way, according to the phase map, the voltage at different pixels (or positions) on the LCOS can be controlled so that the optical signal can be output according to the corresponding branch end. Through the above scheme, before the WSS 601 switches to output the first optical signal to the WSS 603, the WSS 603 has already received the control instruction issued by the network control device, and thus calculates the phase map corresponding to the switching according to the received control instruction. In this way, when the WSS 601 in the original link completes the switching, the WSS 603 receives the first optical signal output by the WSS 601, and can quickly switch to output the received optical signal to the common end according to the pre-calculated phase map.

[0082] Therefore, through the above scheme, the WSS in the new link (i.e. the WSS 603) does not need to wait for the WSS in the original link (i.e. the WSS 601) to complete the switching of the true light and the false light, but starts to calculate the corresponding phase map at the same time as the switching of the true light and the false light of the WSS in the original link, which can reduce the time consumption of the switching and improve the efficiency of the switching between the links, and realizes the quick switching of the transmission of the optical signal from the original link to the new link.

[0083] In a possible implementation, the wavelength range of the first optical signal satisfies 1530 nanometers to 1565 nanometers, i.e. the first optical signal is a C-band optical signal. Optionally, the wavelength range of the first optical signal satisfies 1530 nanometers to 1625 nanometers, i.e. the first optical signal is a C+L-band optical signal.

[0084] In a possible implementation, the network control device can also detect the transmission quality of the first optical signal, determine that the transmission quality of the first optical signal does not satisfy a threshold, and issue a control instruction (i.e. a first control instruction) to the WSS 601.

[0085] Of course, the above is only one possible scenario of the switching of the WSS in the optical communication network, and the WSS can also perform similar switching in other scenarios. For example, in the scenario of rerouting or capacity expansion of the service transmission in the optical communication network, i.e. when a certain transmission node on the link needs to perform the add-drop operation, the optical communication network can also realize the control of the WSS to perform the corresponding switching through other corresponding configurations without waiting for the network control device to detect the quality of the optical signal.

[0086] In a possible implementation, the wavelength range of the first optical signal satisfies 1530 nanometers to 1625 nanometers.

[0087] Optionally, the optical communication network 60 further comprises a dummy light output module 606 (DL 606 in FIG. 6), wherein the DL 606 is connected to the other branch end of the WSS 603.

[0088] Specifically, as shown in FIG. 6, the other branch end of the WSS 603 receives the dummy light (identified as a second light signal) output by the DL 606 and outputs the second light signal to the common end of the WSS 603. Then, the WSS 603 switches to output the first light signal to the common end of the WSS 603 in response to the second control instruction, including gradually increasing the optical power of the real light (the first light signal) output to the common end of the WSS 603 and gradually decreasing the optical power of the dummy light (the second light signal) output to the common end of the WSS 603. In this way, the optical power of the entire wavelength band of the light signal in the link during the switching process can be ensured not to drop, so that the optical power of the light signal transmitted in the link can be kept stable, thereby realizing smooth switching of the real and dummy light.

[0089] In a possible implementation, the optical communication network 60 further comprises a dummy light output module 607 (DL 607 in FIG. 6), wherein the DL 607 is connected to the other branch end of the WSS 602.

[0090] Specifically, as shown in FIG. 6, the other branch end of the WSS 602 is configured to receive the dummy light (identified as a third light signal) output by the DL 607. The WSS 602 can receive a control instruction (identified as a third control instruction) issued by the network control device and switch to output the third light signal to the common end of the WSS 602 in response to the third control instruction. In this way, when the original link fails, the WSS 602 can ensure that the original link can normally transmit the light signal (i.e., the dummy light) by filling the dummy light (the third light signal) output by the DL 607 into the channel corresponding to the real light (the first light signal), thereby reducing the impact of switching of any WSS on the transmission capacity of the link. It should be noted that the above process is only an example of a possible switching process when the original link fails and the links are switched. For example, the failure can be a transmission failure between other nodes on the original link.

[0091] In a possible implementation, the WSS 602 switches to output the third light signal to the common end of the second WSS in response to the third control instruction, including gradually increasing the optical power of the dummy light (the third light signal) output to the common end of the WSS 602 and gradually decreasing the optical power of the real light (the first light signal) output to the common end of the WSS 602.

[0092] Optionally, the optical communication network 60 further comprises: a WSS 604 and a WSS 605; a common end of the WSS 604 is connected to a common end of the WSS 603, and a branch end of the WSS 604 is connected to a branch end of the WSS 605.

[0093] Specifically, in combination with FIG. 6, the WSS 604 can receive the control instruction (identified as the fourth control instruction) issued by the network control device, and transmit the second optical signal to the fifth WSS in response to the fourth control instruction. In this way, before the switchover of the original link and the new link is completed, the new link can normally transmit the optical signal (false light) through the other two WSSs (WSS 604 and WSS 605), ensuring the smoothness of the link. Further, the true light (first optical signal) transmitted by the WSS 601 to the WSS 603 can be normally transmitted in the new link through the WSS 604 and the WSS 605.

[0094] In a possible implementation, the network control device issues the first control instruction to the WSS 601 and issues the fourth control instruction to the WSS 604. In this way, after the WSS 601 receives the first control instruction issued by the network control device, the WSS 604 receives the fourth control instruction issued by the network control device.

[0095] Exemplarily, based on the architecture shown in FIG. 6, the process of link switching of the optical communication network is described as follows:

[0096] Initially, the original link is normally working, and the first optical signal (true light) is transmitted in the original link. That is, the first optical signal is input from the common end of the WSS 601 to the WSS 601, transmitted from the branch end 1 of the WSS 601 to the branch end of the WSS 602, and continues to be transmitted in the original link. Under the condition that the original link is normally working, the true light will not be switched to the branch end 2 of the WSS 601 (shown by the dashed line in FIG. 6). At this time, the channel corresponding to the waveband in the new link transmits the false light (or the new link transmits the false light of the full waveband), so as to ensure the transmission stability of the link.

[0097] When the original link fails, the network control unit issues a first control instruction to the WSS 601, the WSS 601 parses the received first control instruction, calculates the phase map corresponding to the LCOS, and loads it into the LCOS module. In this way, the WSS 601 will switch the branch end of the output true light, that is, the true light output through the branch end 1 will be switched to be output through the branch end 2. At the same time that the network control device issues the first control instruction to the WSS 601 (that is, at this time the WSS 601 has not completed the switching, and the first optical signal has not been switched to be output by the branch end 2 to the WSS 603), a fourth control instruction is issued to the WSS 604, and the WSS 604 of the new link (as well as the WSS with similar functions to the WSS 604 in other nodes of the new link) will transmit the false light originally blocked to the WSS 605.

[0098] Further, the WSS 604 transmits the false light to the WSS 605 according to the fourth control instruction, and after ensuring that the transmission of the new link is smooth, the WSS 603 of the new link receives the true light transmitted by the branch end 2 of the WSS 601 and the false light transmitted by the DL 606, and will perform true-false light smooth switching, replacing the corresponding wave band in the transmitted false light with true light, thereby realizing the completion of the switching between the links.

[0099] In a possible implementation, when the original link fails, the network control unit first issues a control instruction to the WSS 602, so that the WSS 602 starts to perform true-false light switching, that is, replaces the corresponding wave band of the transmitted true light with false light, to ensure that the original link can be normally transmitted. Before the WSS 602 completes the switching, the network control unit also issues a first control instruction to the WSS 601 to control the WSS 601 to perform corresponding switching.

[0100] Based on the above process, in order to reduce the switching time, the true-false light smooth switching technology is usually used at the WSS (referring to FIG. 4). Among them, the true-false light smooth switching needs to be performed in sequence in a node in the optical communication network. Specifically, after the WSS 601 completes the true-false light switching, the WSS 603 performs switching again.

[0101] Of course, in order to further reduce the switching time, based on the scheme provided by the above embodiments of the present application (referring to FIG. 6), the network control unit can issue a control instruction to the WSS 603 before the WSS 601 completes the switching, so that the WSS 603 calculates the phase map corresponding to the LCOS according to the received control instruction, and loads it into the LCOS module. In this way, after the WSS 601 completes the switching and transmits the true light to the WSS 603, the WSS 603 does not need to wait for the control instruction issued by the network control unit, but can directly start to perform true-false light smooth switching according to the pre-calculated phase map.

[0102] For example, referring to FIG. 7, the embodiment of the present application provides a schematic diagram of switching time. In combination with FIG. 7, the horizontal axis is time, and the vertical axis is different switching modes. Mode one is a mode of switching from the original link to the new link in order (referring to FIG. 5). Mode two is a mode of switching from the original link to the new link when the transmission between the WSS 601 and the WSS 602 deployed in the same node fails (referring to FIG. 6). Mode three is a mode of switching from the original link to the new link when the transmission between other nodes on the original link fails (referring to FIG. 6).

[0103] Based on the above switching process, in combination with FIG. 7, the above switching modes are described as follows:

[0104] Mode one: when the original link fails, the WSS 602 switches the true light and the false light, then the WSS 601 switches the branch end of the output true light, and finally the WSS 603 switches the true light and the false light. In this way, the switching time of the optical communication network 60 from the original link to the new link is T=T1+T2+T3. Wherein, T1 is the time of the WSS 602 performing true-false light smooth switching, T2 is the response time of the WSS (such as WSS 601) deployed in the same node or different node as the WSS 602, and T3 is the time of the WSS 603 performing true-false light smooth switching.

[0105] Mode two: when the transmission between the WSS 601 and the WSS 602 in the same node on the original link fails, the transmission between the WSS 601 and the WSS 602 is interrupted at this time. The network control device first issues a control instruction to the WSS 601, and the WSS 601 loads the phase diagram and performs corresponding switching in response to the received control instruction. During this period, the network control device issues a control instruction to the WSS 603 deployed in the same node as the WSS 601 and the WSS 604 deployed in other nodes. Wherein, the WSS 603 analyzes the received control instruction and calculates the phase diagram of the LCOS. When the WSS 601 completely switches the true light to the WSS 603, the WSS 603 has completed the calculation of the phase diagram of the LCOS, and the LCOS can directly load the phase diagram to perform true-false light smooth switching. In this way, the switching time of the optical communication network 60 from the original link to the new link is T=T1+T2-τ+T3-τ. Wherein, τ is the time of the network control device issuing a control instruction and the WSS analyzing and calculating the control instruction, thereby further reducing the switching time and improving the rate of link switching.

[0106] The third mode: when the transmission between other nodes on the original link fails, the optical communication network 60 switches according to the process described in FIG. 6. The network control device first issues a control instruction to the WSS 602, so that the WSS 602 starts to switch the real light and the false light, that is, replaces the corresponding waveband of the transmitted real light with the false light. Before the WSS 602 completes the switching, the network control unit also issues a control instruction to the WSS 601, and the WSS 601 responds to the received control instruction, loads the phase map and performs the corresponding switching. During this period, the network control device issues a control instruction to the WSS 603 deployed in the same node as the WSS 601 and the WSS 604 deployed in other nodes. The WSS 603 parses the received control instruction and calculates the phase map of the LCOS. When the WSS 601 completely switches the real light to the WSS 603, the WSS 603 has completed the calculation of the phase map of the LCOS, and the LCOS can directly load the phase map to perform smooth switching between the real light and the false light. In this way, the switching time from the original link to the new link in the optical communication network 60 is T=T2+T3-τ.

[0107] Based on the above process, an exemplary switching process diagram is provided by the embodiments of the present application, as shown in FIG. 8. In FIG. 8, the horizontal axis represents time, and the vertical axis represents optical power. Curve C represents the proportion of optical power in the optical signal output by the real light at the common end of the WSS 603 in the new link when the conventional switching mode (the first mode shown in FIG. 7) is used. Curve D represents the proportion of optical power in the optical signal output by the real light at the common end of the WSS 603 in the new link when the switching mode (the third mode shown in FIG. 7) described in the embodiments of the present application is used. Curve F represents the proportion of optical power in the optical signal output by the false light at the common end of the WSS 603 in the new link when the conventional switching mode (the first mode shown in FIG. 7) is used. t1 represents the time when the network control unit in the optical communication network 60 issues an instruction to control the switching of the WSS 603. t2 represents the time when the WSS 603 in the optical communication network 60 completes the switching between the real light and the false light.

[0108] As shown in FIG. 8, if the optical communication network 60 uses the sequential switching mode to switch between the links, it needs to wait for the WSS 601 in the original link to complete the switching (output the real light to the WSS 603) before issuing a control instruction to control the WSS 603 to switch between the real light and the false light, which will result in a longer time consumption for switching between the links.

[0109] As shown in curve D, if the optical communication network 60 adopts the switching mode described in the embodiments of the present application to perform switching between links, the optical communication network 60 sends a control instruction to the WSS 603 at the time t2 when the WSS 601 performs switching of the branch end according to the received control instruction and the switching (transmitting the true light to the WSS 603) has not been completed. The WSS 603 can calculate the phase pattern of the LCOS by analyzing the received control instruction. When the WSS 601 completes the switching and transmits all the true light to the WSS 603 through the branch end 2, the WSS 603 has completed the calculation of the phase pattern of the LCOS. In this way, the proportion of the optical power in the optical signal output by the common end of the WSS 603 is greatly improved, and the time consumption of switching between links is shorter.

[0110] In the above embodiments of the present application, by sending corresponding control instructions to the WSSs (including the WSS 601, the WSS 602 and the WSS 603), the WSSs can be controlled to calculate the phase pattern to be loaded by the LCOS in advance, thereby shortening the time consumption of switching between links.

[0111] It should be noted that the time of sending the control instruction to different WSSs is not limited to the above-mentioned several possible scenarios described in the embodiments of the present application. Alternatively, before the WSS starts to perform the corresponding switching, the optical communication network 60 can first send corresponding control instructions (the first control instruction, the second control instruction and the third control instruction) to the WSSs (including the WSS 601, the WSS 602 and the WSS 603). Further, based on the received control instruction, the WSSs (including the WSS 601, the WSS 602 and the WSS 603) can calculate the phase pattern of the LCOS corresponding to the switching. In this way, when the switching needs to be performed, the WSS 601, the WSS 602 and the WSS 603 can all respond quickly.

[0112] Based on the architecture shown in FIG. 6, an exemplary optical communication network is provided, as shown in FIG. 9. The optical communication network 60 further includes a plurality of WSSs (the WSS 608 and the WSS 609 in FIG. 9) and a plurality of dummy light output devices (the DL 610 in FIG. 9).

[0113] In a possible implementation, one WSS in the optical communication network 60 can include a plurality of WSSs. For example, as shown in FIG. 9, the WSS 601 includes a plurality of WSSs (the WSS 601-1 to the WSS 601-4 in FIG. 9).

[0114] It is understandable that, for the convenience of illustration, only the optical communication network shown in FIG. 9 is taken as an example here, and the specific structure of the optical communication network, the number of included devices, the type of devices, etc. should not be limited. In a possible implementation, the optical communication network further includes more nodes and more WSSs. For example, in combination with FIG. 9, the optical communication network further includes a plurality of WSSs (WSS 608 and WSS 609 in FIG. 9).

[0115] Specifically, in combination with FIG. 9, WSS 601-1 to WSS 601-4 included in WSS 601 can transmit optical signals of different wavelengths to different directions, and then WSS 602 can combine the optical signals transmitted to different directions (i.e., different dimensions), thereby completing the service scheduling of the original link. Of course, WSS 601 and WSS 602 are only taken as examples for illustration here, and the WSSs in other nodes in the original link can also achieve similar functions, such as WSS 601 and WSS 602. Generally, in order to ensure the stability of the communication network, a dummy light output device is connected at the branch end of WSS 602 for filling the channels corresponding to the wavelengths that do not carry service data.

[0116] Generally, a WSS includes one input (output) port and N output (input) ports, and includes a plurality of optical elements and beam adjusting elements (i.e., LCOS) inside. When the combined signals including a plurality of wavelengths are connected to one input port (i.e., common end) of the WSS (e.g., WSS 601), the optical signals of different wavelengths will be transmitted to different regions of the LCOS by the optical elements inside the WSS. The LCOS can adjust the transmission direction of the light beams of the optical signals of different wavelengths by loading the corresponding phase map, so as to transmit the optical signals of different wavelengths to different output ports (i.e., branch end), and the WSS realizes the function of splitting the wavelengths.

[0117] Similarly, the optical signals of different directions or different wavelengths are connected to a plurality of input ports (i.e., branch end) of the WSS (e.g., WSS 602), and the LCOS inside the WSS can adjust the transmission direction of the light beams of the optical signals of different directions or different wavelengths, so that the optical signals of different directions or different wavelengths can be output through one output port (i.e., common end), and the WSS realizes the function of combining the wavelengths.

[0118] When part of the wavelengths in the optical communication network do not carry service data, the DL 607 connected with the WSS 602 can fill the corresponding channels with dummy light to ensure that the optical signals transmitted in the link are always in the full-band full-wave state, so as to keep the transmission quality of the link stable.

[0119] Based on the architecture shown in FIG. 6, referring to FIG. 10, an embodiment of the present application provides a schematic diagram of an optical communication network. For ease of illustration, in the following embodiments of the present application, the optical communication network is identified as optical communication network 70.

[0120] Referring to the optical communication system 60 shown in FIG. 6, in combination with FIG. 10, the optical communication network 70 includes at least three WSSs (WSS 601, WSS 602, and WSS 603 in FIG. 10), wherein any WSS includes one common end and multiple branch ends. The connection relationship between the WSS 601, the WSS 602, and the WSS 603 can be referred to the description of the above factual example of the present application, which will not be described here again.

[0121] Optionally, the optical communication network 70 further includes one or more optical amplifiers (OAs) deployed on the link. The OA is used to provide gain for the optical signal, i.e., to amplify the optical signal during the transmission of the optical signal along the optical fiber to compensate for the attenuation of the optical signal during the transmission, so as to improve the transmission distance of the optical communication system and ensure the transmission effect of the optical communication system. For example, in combination with FIG. 10, the original link of the optical communication network 70 includes OA 701 and OA 702, and the new link includes OA 703 and OA 704. Of course, in other examples, the optical communication network can further include more OAs, and the embodiments of the present application do not limit the number and types of devices included in the optical communication network.

[0122] It is not difficult to understand that, for ease of illustration, only the optical communication network 70 shown in FIG. 10 is taken as an example here, and the specific structure of the optical communication network, the number of devices included, the types of devices, etc. should not be limited by this.

[0123] Specifically, in combination with FIG. 10, in the optical communication network for transmitting C-band (also referred to as single-C system), the wavelength range of the transmitted optical signal is 1530 nm to 1565 nm, i.e., the optical signal of the C-band. In the single-C system, the optical signal for service transmission is usually transmitted through the original link, and no optical signal is transmitted in the new link. When the original link fails, it needs to be switched from the original link to the new link, i.e., the true light is switched to the new link for transmission.

[0124] Since the new link in the single-C system usually does not transmit an optical signal, the optical amplifiers (i.e., OA 703, OA 704) in the new link are in an inoperative state (i.e., no light state, the optical power of the optical signal transmitted to the OA 703 and the OA 704 is 0). When switching between the links is performed, the optical amplifiers need to be switched from the inoperative state to the operative state, and the response time is relatively long. Then, the time consumed by the single-C system to complete the switching between the links includes not only the time for the WSS to switch, but also the response time for the optical amplifiers to change from no light to light (the optical power of the optical signal transmitted to the OA 703 and the OA 704 is not 0) after the switching between the links is implemented. Usually, the optical amplifiers need to reach a certain threshold, that is, the optical power of the optical signal transmitted to the optical amplifiers reaches a certain threshold, and the optical amplifiers will start to respond, which will result in a long time consumed by the switching between the links.

[0125] Based on the above problems, for example, referring to FIG. 11, the embodiment of the present application provides a curve diagram of the change of the optical power. As shown in FIG. 11, the abscissa represents time; the ordinate represents the optical power of the optical signal, the solid curve represents the change of the optical power of the new link when the switching mode of mode one is adopted, and the dotted curve represents the change of the optical power of the new link when the switching mode of mode two is adopted.

[0126] Mode one: when the original link fails, the links of the optical communication network 70 are switched according to the order (for example, the steps (1) to (3) described above) as shown by the solid curve. At T(b) moment, the optical power of the branch end of the WSS 601 connected to the WSS 603 reaches the threshold of the optical amplifier.

[0127] Mode two: when the original link fails, the links of the optical communication network 70 are switched according to the process described above with reference to FIG. 6, and the WSS 601 switches the optical signal output to the WSS 602 through the branch end to the WSS 603 through another branch end. At T(a) moment, the optical power of the branch end of the WSS 601 connected to the WSS 603 reaches the threshold of the optical amplifier. Wherein, T(a) is less than T(b).

[0128] Specifically, based on FIG. 10, the optical communication network 70 can issue a control instruction to the WSS 603 in the new link through the network control device during the switching process of the WSS 601, so as to control the optical power of the new link to quickly reach the threshold of the optical amplifier. Since the WSS 601 implements the switching of the branch end by loading the phase diagram of the LCOS to switch, the optical communication network 70 can set the phase diagram loaded by the LCOS by issuing a control instruction to the WSS 601 in the new link, so that the optical power of the branch end of the WSS 601 connected to the WSS 603 quickly reaches the threshold of the optical amplifier.

[0129] Based on 2 shown, exemplary, with reference to FIG. 12, the embodiments of the present application provide a schematic diagram of a phase diagram. In conjunction with FIG. 12, the abscissa represents the position, i.e. the position of the optical signal incident to the WSS 601 to the aluminized electrode 204 of the WSS 601; the ordinate represents the voltage value required by the aluminized electrode 204 of the WSS 601 to achieve phase modulation on the optical signal. Wherein, the solid broken line represents the phase diagram loaded by the WSS 601 when using the above-mentioned manner one. The dotted broken line represents the phase diagram loaded by the WSS 601 when using the above-mentioned manner two.

[0130] Specifically, in conjunction with FIG. 12, at the position G on the aluminized electrode 204 of the WSS 601, when using the manner one, the voltage value at this position needs to be set to V(a), when using the manner two, the voltage value at this position needs to be set to V(b). When using the manner two, the optical communication network 70 can set the phase diagram loaded by the LCOS by issuing a control instruction to the WSS 601 in the new link, and directly set the voltage value at the position G to the voltage value V(c), wherein the voltage value V(c) is lower than V(b), thereby ensuring that the optical power output by the branch end 2 of the WSS 601 connected to the WSS 603 can quickly reach the threshold of the optical amplifier. Of course, in order to facilitate the description, only the position G is taken as an example here, and it should not be construed as a limitation on the embodiments of the present application.

[0131] Through the above-mentioned scheme, the optical amplifiers (i.e. OA 703 and OA 704) in the new link can change from no light to light before the WSS 601 completes the switching, and start to respond. In this way, through the switching mode described in the above-mentioned embodiments of the present application, the response time of the optical amplifier can be reduced, and the rate of switching between links can be improved.

[0132] In the embodiments described above, all or some of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or some of the embodiments can be implemented in the form of a computer program product storing computer program instructions. The computer program instructions are executed in a computer to implement the procedures or functions described in the embodiments of the present application. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer program instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer program instructions can be transmitted from a website, a computer, a server or a data center to another website, computer, server or data center through a wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or data storage device such as one or more servers, data centers, etc. integrated with one or more media. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, solid state disk (SSD)), etc. In the embodiments of the present application, the computer can include the device described above.

[0133] Although the present application is described herein in conjunction with various embodiments, those skilled in the art will appreciate that other changes in the described embodiments can be understood and implemented by those skilled in the art upon viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. Some measures described in mutually different dependent claims can be combined to produce good results.

[0134] Although the present application has been described in connection with certain specific features and embodiments thereof, it is to be understood that it is provided as an example to the best of the applicant's knowledge and that various modifications and combinations of the described features and embodiments are possible and are within the spirit and scope of the application. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense, and all such modifications and variations are considered within the scope of the present application as defined by the following claims and their equivalents. Obviously, many modifications and variations of the present application are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the claims and their equivalents, the present application can be practiced otherwise than as specifically described.

Claims

1. An optical communication network, characterized in that The optical communication network includes at least three wavelength selective switches, each of which includes a common end and multiple branch ends; The first branch end of the first wavelength selective switch among the at least three wavelength selective switches is connected to the first branch end of the second wavelength selective switch among the at least three wavelength selective switches; The second branch end of the first wavelength selective switch is connected to the first branch end of the third wavelength selective switch among the at least three wavelength selective switches; The common end of the first wavelength selective switch is used to receive the first optical signal and output the first optical signal to the second wavelength selective switch; The first wavelength selective switch is further configured to receive a first control instruction issued by a network control device, and switch to outputting the first optical signal to the third wavelength selective switch based on the first control instruction; The third wavelength selective switch is configured to receive a second control instruction issued by the network control device before the first wavelength selective switch switches to output the first optical signal to the third wavelength selective switch; The third wavelength selective switch is further configured to, after receiving the first optical signal, switch to output the first optical signal to the common end of the third wavelength selective switch in response to the second control instruction.

2. The optical communication network according to claim 1, wherein: The optical communication network further comprises: a first dummy light output module, wherein the first dummy light output module is connected to the second branch end of the third wavelength selective switch; The second branch end of the third wavelength selective switch is used to receive the second optical signal output by the first dummy light output module, and output the second optical signal to the common end of the third wavelength selective switch; The switching to output the first optical signal to the common end of the third wavelength selective switch in response to the second control instruction comprises: The optical power of the first optical signal output to the common end of the third wavelength selective switch is gradually increased, and the optical power of the second optical signal output to the common end of the third wavelength selective switch is gradually decreased.

3. The optical communication network according to claim 2, wherein: The optical communication network further comprises: a second dummy light output module, wherein the second dummy light output module is connected to the second branch end of the second wavelength selective switch; The second branch end of the second wavelength selective switch is used to receive the third optical signal output by the second dummy light output module; The second wavelength selective switch is further configured to receive a third control instruction issued by the network control device, and in response to the third control instruction, switch to outputting the third optical signal to the common end of the second wavelength selective switch.

4. The optical communication network according to claim 3, wherein: The switching to output the third optical signal to the common end of the second wavelength selective switch in response to the third control instruction comprises: The optical power of the third optical signal output to the common end of the second wavelength selective switch is gradually increased, and the optical power of the first optical signal output to the common end of the second wavelength selective switch is gradually decreased.

5. The optical communication network according to any one of claims 1 to 4, characterized in that: The optical communication network further comprises: a fourth wavelength selective switch and a fifth wavelength selective switch; The common end of the fourth wavelength selective switch is connected to the common end of the third wavelength selective switch, and the first branch end of the fourth wavelength selective switch is connected to the first branch end of the fifth wavelength selective switch; The fourth wavelength selective switch is further configured to receive a fourth control instruction issued by the network control device, and transmit the second optical signal to the fifth wavelength selective switch in response to the fourth control instruction.

6. The optical communication network according to any one of claims 1 to 5, characterized in that: The network control device is further configured to send a first control instruction to the first wavelength selective switch when it is determined that the transmission quality of the first signal light does not meet a threshold.

7. The optical communication network according to claim 1, wherein: The wavelength range of the first optical signal meets the following requirements: 1530 nanometers to 1565 nanometers.

8. The optical communication network according to any one of claims 2 to 6, characterized in that: The wavelength range of the first optical signal satisfies: 1530 nanometers to 1625 nanometers.

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