Optical switching node and optical communication system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2026-06-16
Smart Images
Figure CN122227111A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical communication technology, and in particular to an optical switching node and an optical communication system. Background Technology
[0002] With the development of communication technology, optical communication systems are being used more and more widely. An optical communication system typically includes multiple optical switching nodes, which can be networked in various ways.
[0003] In related technologies, an optical switching node comprises multiple switching unit groups, each group including multiple line-side switching units and at least one tributary-side switching unit. Any two line-side switching units in these multiple switching unit groups are interconnected. Each tributary-side switching unit is connected to each line-side switching unit in each of all the multiple switching unit groups.
[0004] Under normal circumstances, for the first switching unit group in a plurality of switching unit groups, the tributary-side switching unit sends a service optical signal to the line-side switching unit, and the line-side switching unit sends the service optical signal to the optical switching node of the first line dimension connected to the line-side switching unit.
[0005] If the optical fiber link between the line-side switching unit in the first switching unit group and the optical switching node in the first line dimension fails, the branch-side switching unit can send the service optical signal to the line-side switching unit in the second switching unit group. The line-side switching unit in the second switching unit group then sends the service optical signal to the optical switching node in the second line dimension, and the optical switching node in the second line dimension forwards the service optical signal to the optical switching node in the first line dimension, thereby improving the reliability of data transmission in the optical communication system.
[0006] However, the large number of fiber connections between the various switching units in this type of optical switching node leads to a complex structure. Summary of the Invention
[0007] This application provides an optical switching node and an optical communication system that can simplify the structure of the optical switching node.
[0008] In a first aspect, this application provides an optical switching node, which includes a first optical cross-connect device and M switching unit groups, where M is an integer and M is greater than 1. Each switching unit group includes at least one tributary-side switching unit and at least one line-side switching unit, and each tributary-side switching unit in each switching unit group is connected to each line-side switching unit. The at least one line-side switching unit includes a first line-side switching unit, which is connected to the first optical cross-connect device. The first optical cross-connect device is used to transmit the optical signal output by the first line-side switching unit in the first switching unit group to the first line-side switching unit in the second switching unit group, and to transmit the optical signal output by the first line-side switching unit in the second switching unit group to the first line-side switching unit in the first switching unit group. The first switching unit group and the second switching unit group are any two switching unit groups from the M switching unit groups.
[0009] The first optical crossover device is connected to the first line-side switching unit in at least two switching unit groups respectively. The first optical crossover device can realize the exchange of optical signals between the first line-side switching unit in the first switching unit group and the first line-side switching unit in the second switching unit group, thereby realizing the optical signal passage between the corresponding dimensions of at least two switching unit groups.
[0010] In related technologies, each line-side switching unit is connected to the others via optical fibers. A larger value for M indicates a greater number of fiber connections between line-side switching units, and thus more ports for the first line-side switching unit to connect with other line-side switching units. However, in this embodiment, each first line-side switching unit is connected to a first optical cross-connect device, enabling each line-side switching unit to transmit signals to other first line-side switching units via the first optical cross-connect device. This reduces the number of fiber connections for each first line-side switching unit, thereby reducing the overall number of fiber connections in the optical switching node and simplifying its structure. Furthermore, the reduced number of fiber connections for each first line-side switching unit also reduces the number of ports required, thus lowering its cost.
[0011] In a first possible implementation, the optical switching node further includes a second optical cross-connect device, and the first line-side switching unit is also connected to the second optical cross-connect device, which serves as a backup for the first optical cross-connect device. When the first optical cross-connect device fails, its function can be restored using the second optical cross-connect device. This improves the reliability of data transmission at the optical switching node.
[0012] Optionally, each line-side switching unit in each switching unit group is connected to the first optical cross-connect device and the second optical cross-connect device, respectively.
[0013] In some embodiments, each tributary-side switching unit is connected to both the first optical cross-connect device and the second optical cross-connect device. The first optical cross-connect device is further configured to transmit local optical signals output from any tributary-side switching unit to any line-side switching unit connected to the first optical cross-connect device, and to transmit line-side optical signals output from any line-side switching unit connected to the first optical cross-connect device to the aforementioned tributary-side switching unit. The second optical cross-connect device is further configured to transmit local optical signals output from any tributary-side switching unit to any line-side switching unit connected to the second optical cross-connect device, and to transmit line-side optical signals output from any line-side switching unit connected to the second optical cross-connect device to the aforementioned tributary-side switching unit.
[0014] In this way, each tributary-side switching unit can transmit signals with line-side switching units in other switching unit groups through the first optical cross-connect device or the second optical cross-connect device. Compared with each tributary-side switching unit being connected to each line-side switching unit in other switching unit groups, this reduces the number of fiber connections between the tributary-side switching unit and other devices in the optical switching node, as well as the number of ports used by the tributary-side switching unit to connect with other devices in the optical switching node.
[0015] In other embodiments, each tributary-side switching unit is connected to each line-side switching unit in other switching unit groups. In this case, the tributary-side switching unit is not connected to the first and second optical cross-connect devices, thus reducing the number of ports available for connection to other devices in the optical switching node, which helps to reduce the cost of the first and second optical cross-connect devices.
[0016] In a second possible implementation, the optical switching node further includes a third optical cross-connect device, and each of the at least two switching unit groups further includes a second line-side switching unit, which is connected to the third optical cross-connect device. The third optical cross-connect device is used to transmit the optical signal output from the second line-side switching unit in the first switching unit group to the second line-side switching unit in the second switching unit group; and to transmit the optical signal output from the second line-side switching unit in the second switching unit group to the second line-side switching unit in the first switching unit group.
[0017] In this embodiment, within the same switching unit group, some line-side switching units are connected to the first optical cross-connect device, while other line-side switching units are connected to the third optical cross-connect device. This reduces the number of line-side switching units that each optical cross-connect device needs to connect to, thus reducing the number of ports on the optical cross-connect device and consequently lowering its cost.
[0018] Optionally, in each switching unit group, the number of first line-side switching units is greater than or equal to the number of second line-side switching units, wherein the first line-side switching units are used to connect to the main optical fiber link, and the second line-side switching units are used to connect to the backup optical fiber link.
[0019] When the number of first-line-side switching units equals the number of second-line-side switching units, 1:1 protection can be provided on one line dimension. When the number of first-line-side switching units is greater than the number of second-line-side switching units, if the line-side switching units in the two switching unit groups are connected to the same optical switching node via optical fiber links, more primary optical fiber links can be protected with fewer backup optical fiber links, thereby saving on optical fiber link leasing costs.
[0020] Optionally, each branch-side switching unit is connected to both the first optical cross-connect device and the third optical cross-connect device. The first optical cross-connect device is further configured to transmit the local optical signal output from any branch-side switching unit to any line-side switching unit connected to the first optical cross-connect device, and to transmit the line-side optical signal output from any line-side switching unit connected to the first optical cross-connect device to the aforementioned branch-side switching unit. The third optical cross-connect device is further configured to transmit the local optical signal output from any branch-side switching unit to any line-side switching unit connected to the third optical cross-connect device, and to transmit the line-side optical signal output from any line-side switching unit connected to the third optical cross-connect device to the aforementioned branch-side switching unit.
[0021] In this way, each tributary-side switching unit can transmit signals with line-side switching units in other switching unit groups through the first or third optical cross-connect device. Compared with each tributary-side switching unit being connected to each line-side switching unit in other switching unit groups, this reduces the number of fiber connections between the tributary-side switching unit and other devices in the optical switching node, as well as the number of ports used by the tributary-side switching unit to connect with other devices in the optical switching node.
[0022] In other embodiments, each tributary-side switching unit is connected to each line-side switching unit in the other switching unit groups. In this case, the tributary-side switching unit is not connected to the first and third optical cross-connect devices, thus reducing the number of ports available for connection to other devices in the optical switching node, which helps to reduce the cost of the first and third optical cross-connect devices.
[0023] In some embodiments, the first switching unit group and the second switching unit group correspond to different directions. That is, the optical switching node connected to the line-side switching unit in the first switching unit group is different from the optical switching node connected to the line-side switching unit in the second switching unit group.
[0024] In other embodiments, the first switching unit group and the second switching unit group correspond to the same direction. That is, the optical switching node connected to the line-side switching unit in the first switching unit group is the same as the optical switching node connected to the line-side switching unit in the second switching unit group.
[0025] Optionally, the first optical cross-connect device is a wavelength selected switch (WSS) or an optical switch (SW). When the first optical cross-connect device is a WSS, wavelength-level optical signal scheduling can be achieved; when the first optical cross-connect device is a port-level SW, port-level optical signal scheduling can be achieved.
[0026] Optionally, the second optical cross-connect device is a WSS or a port-level SW. When the second optical cross-connect device is a WSS, wavelength-level optical signal scheduling can be achieved; when the second optical cross-connect device is a port-level SW, port-level optical signal scheduling can be achieved.
[0027] Optionally, the third optical cross-connect device is a WSS or a port-level SW. When the third optical cross-connect device is a WSS, wavelength-level optical signal scheduling can be achieved; when the third optical cross-connect device is a port-level SW, port-level optical signal scheduling can be achieved.
[0028] Optionally, the line-side switching unit includes 1×N WSS, 1×N port-level SW, or 1×N coupler.
[0029] Optionally, the tributary-side switching unit includes 1×N WSS or 1×N port-level SW.
[0030] Secondly, this application provides an optical communication system. The optical communication system includes multiple optical switching nodes, wherein a first optical switching node is connected to at least two other optical switching nodes besides the first optical switching node. The first optical switching node is any of the optical switching nodes provided in the first aspect. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the structure of an optical communication system provided in an embodiment of this application;
[0032] Figure 2 This is a schematic diagram of the structure of an optical switching node provided in an embodiment of this application;
[0033] Figure 3 This is a schematic diagram of another optical switching node provided in an embodiment of this application;
[0034] Figure 4 This is a schematic diagram of the structure of another optical switching node provided in the embodiments of this application;
[0035] Figure 5 This is a schematic diagram of another optical switching node provided in an embodiment of this application;
[0036] Figure 6 This is a schematic diagram of another optical switching node provided in an embodiment of this application;
[0037] Figure 7 This is a schematic diagram of another optical switching node provided in the embodiments of this application.
[0038] Figure Labels
[0039] 10a First switching unit group; 10b Second switching unit group;
[0040] 11 branch roadside switching units; 12 line-side switching units;
[0041] 11a Second WSS; 11b Multiplexer; 11c Demultiplexer; 11d, 11e Optical amplifiers;
[0042] 21 First optical cross-connect device; 22 Second optical cross-connect device; 23 Third optical cross-connect device. Detailed Implementation
[0043] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0044] This application provides an optical communication system comprising multiple optical switching nodes. These optical switching nodes can be networked in any manner, such as a mesh network, a chain network, or a star network. Each optical switching node is connected to at least one other optical switching node, and at least one optical switching node is connected to two other optical switching nodes. Optionally, two connected optical switching nodes are connected via at least one pair of optical fiber links.
[0045] Figure 1 This is a schematic diagram of the structure of an optical communication system provided in an embodiment of this application. For example... Figure 1 As shown, the optical communication system includes three optical switching nodes: optical switching node A, optical switching node B, and optical switching node C. Any two optical switching nodes are connected by at least two pairs of optical fiber links. Each pair of optical fiber links includes a first optical fiber link a and a second optical fiber link b. The first optical fiber link a is used by the first optical switching node to send optical signals to the second optical switching node, and the second optical fiber link is used by the second optical switching node to send optical signals to the first optical switching node. Here, the first and second optical switching nodes can be any two switching nodes in the diagram. For example, the first optical switching node can be optical switching node A, and the second optical switching node can be optical switching node B; or, the first optical switching node can be optical switching node B, and the second optical switching node can be optical switching node C.
[0046] Figure 1 The number of optical switching nodes is just an example; an optical communication system may include a larger number of optical switching nodes, such as four, five, or more.
[0047] For example, Figure 1 In this system, any two optical switching nodes are connected by four pairs of optical fiber links, of which two pairs are primary links and the other two pairs are backup links.
[0048] When there is a normal fiber optic link between optical switching node A and optical switching node B, optical signals can be transmitted between them through the fiber optic link. When all fiber optic links between optical switching node A and optical switching node B fail (e.g., the fiber is disconnected), optical switching node A can send the optical signal to optical switching node C, which will then forward it to optical switching node B.
[0049] This optical communication system is suitable for scenarios with high reliability requirements for data transmission, such as data center interconnection (DCI).
[0050] In one possible implementation, an optical switching node is connected to multiple servers in the same data center (DC), and different optical switching nodes are connected to servers in different DCs.
[0051] In another possible implementation, an optical switching node connects to servers in multiple data centers (DCs) within the same availability zone (AZ), and different optical switching nodes connect to servers in different AZs. Each AZ can have multiple DCs.
[0052] In practice, the distance between two AZs is usually within 100 kilometers (e.g., tens of kilometers).
[0053] In other embodiments, multiple pairs of fiber optic links between two optical switching nodes may not be distinguished as primary or backup.
[0054] The structure of the optical switching node is described below. In this embodiment, the optical switching node includes: a first optical cross-connect device and M switching unit groups, where M is an integer and M is greater than 1. Each switching unit group includes at least one tributary-side switching unit and at least one line-side switching unit, and each tributary-side switching unit in the same switching unit group is connected to each line-side switching unit. At least two of the M switching unit groups include a first line-side switching unit, which is connected to the first optical cross-connect device. The first optical cross-connect device is used to transmit the optical signal output by the first line-side switching unit in the first switching unit group to the first line-side switching unit in the second switching unit group, and to transmit the optical signal output by the first line-side switching unit in the second switching unit group to the first line-side switching unit in the first switching unit group. The first switching unit group and the second switching unit group are any two switching unit groups from the at least two switching unit groups.
[0055] In related technologies, each line-side switching unit is connected to the next via optical fiber. A larger value for M indicates a greater number of fiber connections between line-side switching units, and thus more ports for each line-side switching unit to connect to other line-side switching units. However, in this embodiment, each first line-side switching unit can exchange signals with any other first line-side switching unit simply by connecting to a first optical cross-connect device. Therefore, the number of fiber connections for each first line-side switching unit is smaller, resulting in a reduction in the overall number of fiber connections in the optical switching node, simplifying its structure. Furthermore, the reduced number of fiber connections for each first line-side switching unit also reduces the number of ports required, thus lowering its cost.
[0056] The more first line-side switching units connected to the first optical cross-connect device, the fewer fiber connections are reduced. Therefore, the following explanation will take the case where each line-side switching unit in each switching unit group is a first line-side switching unit (i.e., each line-side switching unit in the optical switching node is connected to the first optical cross-connect device) as an example.
[0057] In other embodiments, some line-side switching units in an optical switching node are not connected to the first optical cross-connect device. These line-side switching units not connected to the first optical cross-connect device can be referred to as non-first line-side switching units. An optical switching node including non-first line-side switching units may fall into the following categories: First, each optical switching unit group includes both first line-side switching units and non-first line-side switching units; Second, some optical switching unit groups contain only first line-side switching units, while others contain only non-first line-side switching units; Third, some optical switching unit groups contain only non-first line-side switching units, while others include both first line-side and non-first line-side switching units; Fourth, some optical switching unit groups include both first line-side and non-first line-side switching units, while others contain only non-first line-side switching units.
[0058] The structure of the optical switching node in this embodiment of the application will be described exemplarily below, taking M equal to 2 as an example. In other embodiments, M can be greater than 2, for example, equal to 3, 4, or 5.
[0059] Figure 2 This is a schematic diagram of the structure of an optical switching node provided in an embodiment of this application. Figure 2As shown, the optical switching node includes a first optical cross-connect device 21 and two switching unit groups. The two switching unit groups are a first switching unit group 10a and a second switching unit group 10b. Each switching unit group includes at least one tributary-side switching unit 11 and at least one line-side switching unit 12. Each tributary-side switching unit 11 in the same switching unit group 10a is connected to each line-side switching unit 12 in the same switching unit group 10a. That is, each tributary-side switching unit 11 in the first switching unit group 10a is connected to each line-side switching unit 12 in the same switching unit group 10a; and each tributary-side switching unit 11 in the second switching unit group 10b is connected to each line-side switching unit 12 in the same switching unit group 10b. In this way, each branch-side switching unit 11 can send the local optical signal to any line-side switching unit 12 in its switching unit group, and then send it to another corresponding optical switching node through that line-side switching unit 12, thereby realizing the uplink of the optical signal; and each branch-side switching unit 11 can receive the line-side optical signal sent by any line-side switching unit 12 in its switching unit group, thereby realizing the downlink of the optical signal.
[0060] Each line-side switching unit 12 in each switching unit group is connected to the first optical cross-connect device 21, that is, each line-side switching unit 12 in each switching unit group is a first line-side switching unit. The first optical cross-connect device 21 is used to transmit the optical signal output by any line-side switching unit 12 in the first switching unit group 10a to any line-side switching unit 12 in the second switching unit group 10b; and to transmit the optical signal output by any line-side switching unit 12 in the second switching unit group 10b to any line-side switching unit 12 in the second switching unit group 10b.
[0061] In this embodiment of the application, the first optical cross-connect device is connected to the first line-side switching unit in each switching unit group. The first optical cross-connect device can realize the exchange of optical signals between the first line-side switching unit in the first switching unit group and the first line-side switching unit in the second switching unit group, thereby enabling optical signal transmission between the dimensions corresponding to at least two switching unit groups.
[0062] In related technologies, each line-side switching unit is connected to the others via optical fibers. A larger value for M indicates a greater number of fiber connections between line-side switching units, and thus more ports for the first line-side switching unit to connect with other line-side switching units. However, in this embodiment, each first line-side switching unit is connected to a first optical cross-connect device, enabling each line-side switching unit to transmit signals to other first line-side switching units via the first optical cross-connect device. This reduces the number of fiber connections for each first line-side switching unit, thereby reducing the overall number of fiber connections in the optical switching node and simplifying its structure. Furthermore, the reduced number of fiber connections for each first line-side switching unit also reduces the number of ports required, thus lowering its cost.
[0063] Furthermore, during the operation of the optical switching node, optical signals are transmitted between the tributary-side switching unit and the line-side switching unit in the same switching unit group for most of the time. In the embodiment of the application, the tributary-side switching unit and the line-side switching unit in the same switching unit group are directly connected. Compared with the connection between the tributary-side switching unit and the line-side switching unit in the same switching unit group through the first optical cross-connect device, the insertion loss is lower and the reliability is higher, which is beneficial to improving the signal transmission quality.
[0064] exist Figure 2 In the illustrated embodiment, each line-side switching unit 12 is connected to another optical switching node (not shown) via a pair of optical fiber links (i.e., a first optical fiber link a and a second optical fiber link b), and all line-side switching units 12 in each switching unit group are connected to the same optical switching node. That is, the line-side switching units 12 in each switching unit group belong to the same direction. For example, Figure 2 The optical switching nodes shown are located in AZ1. The first switching unit group 10a is connected to another optical switching node located in AZ2, meaning that the line-side switching unit 12 of the first switching unit group 10a belongs to the AZ2 direction. The second switching unit group 10b is connected to another optical switching node located in AZ3, meaning that the line-side switching unit 12 of the second switching unit group 10b belongs to the AZ3 direction. All tributary-side switching units in all switching unit groups belong to the local dimension (also known as the tributary dimension).
[0065] In some examples, when Figure 2When the optical fiber links from the optical switching node in the AZ2 direction are all faulty, the branch-side switching unit 11 in the first switching unit group 10a can schedule the optical signal that needs to be sent to the AZ2 direction to the idle line-side switching unit 12 in the second switching unit group 10b corresponding to the AZ3 direction. For example, the line-side switching unit 12 connected to the backup link sends the optical signal to the optical switching node in the AZ3 direction, and then the optical switching node in the AZ3 direction forwards it to the optical switching node in the AZ2 direction.
[0066] In other examples, when the fiber optic link between the optical switching node in AZ2 and the optical switching node in AZ3 fails, the optical switching node in AZ2 can send optical signals to... Figure 2 The first switching unit group 10a of the optical switching node in the first switching unit group 10a is sent by the line-side switching unit 12 in the first switching unit group 10a through the first optical cross-connect device 21 to the line-side switching unit 12 in the second switching unit group 10a, and then sent by the line-side switching unit 12 in the second switching unit group 10a to the optical switching node in AZ3.
[0067] Here, the example of arranging optical switching nodes in units of AZ is used for illustration. In other embodiments, optical switching nodes can be arranged in units of DC, etc.
[0068] Optionally, each switching unit group includes four line-side switching units 12 and two tributary-side switching units 11. Each line-side switching unit 12 is connected to one pair of optical fiber links. Of the four pairs of optical fiber links connected to the four line-side switching units 12, two pairs are primary links and two pairs are backup links.
[0069] In practical applications, among the four pairs of fiber optic links connected by the same switching unit group, in the same direction, two pairs of backup links are arranged in the same optical cable, and two pairs of primary links are arranged in separate optical cables. In this way, a 4-fiber 3-routing plane is formed between the two switching nodes.
[0070] In some examples, one primary link and one backup link are used to transmit data for service 1, while another primary link and another backup link are used to transmit data for service 2. In this case, service 1 and service 2 are two separate fault domains. A failure in the fiber optic link corresponding to service 1 will not affect the data transmission of service 2, thus achieving fault isolation and improving the reliability of data transmission at the optical switching node.
[0071] Optionally, each line-side switching unit 12 includes two first wavelength selected switches (WSS). Each first WSS has a common port and multiple branch ports. One first WSS can transmit the optical signal received from any branch port to the common port (connected to the first fiber optic link a) for output. The other first WSS can transmit any single-wavelength optical signal from the multi-wavelength optical signals received from the common port (connected to the second fiber optic link b) to any branch port for output. That is, the first WSS is a 1×N WSS. It should be noted that, for illustrative purposes, Figure 2 Only one first WSS is shown in the diagram. By employing the first WSS, the line-side switching unit 12 can achieve wavelength-level optical signal scheduling.
[0072] In some other embodiments, the first WSS can be replaced by a 1×N port-level SW, which includes a first port and multiple second ports. At any given time, the first port of the SW is only connected to one of the multiple second ports of the SW, and optical signals can be transmitted between the interconnected first and second ports. When the line-side switching unit 12 uses an SW, the line-side switching unit 12 can achieve port-level optical signal scheduling.
[0073] In other embodiments, the first WSS can be replaced by a 1×N coupler, which includes a first port and multiple second ports. At any given time, the optical signal received at the first port of the coupler can be output from each of the second ports, and the optical signal received at each of the second ports can be output from the first port. When the line-side switching unit 12 uses a coupler, the cost of the line-side switching unit 12 is lower.
[0074] Optionally, each branch-side switching unit 11 includes two second WSS11a. Each second WSS11a has a common port and multiple branch ports. One second WSS11a can transmit the optical signal received at any branch port to the output of the common port, and the other second WSS11a can transmit any single-wavelength optical signal from the multi-wavelength optical signals received at the common port to the output of any branch port. That is, the second WSS11a is a 1×N WSS. It should be noted that, for illustrative purposes, Figure 2 Only one second WSS11a is shown. By employing the second WSS11a, the line-side switching unit 12 can achieve wavelength-level optical signal scheduling.
[0075] For example, each branch-side switching unit 11 further includes a multiplexer 11b and a demultiplexer 11c. The multiplexer is used to multiplex local single-wavelength optical signals and send the multi-wavelength optical signals obtained by multiplexing to the common port of a second WSS 11a. The demultiplexer is used to demultiplex the optical signals output from the common port of another second WSS 11a and demultiplex the single-wavelength optical signals obtained by demultiplexing.
[0076] Optionally, each branch-side switching unit further includes an optical amplifier 11d connected between the multiplexer and the corresponding second WSS11a, and an optical amplifier 11e connected between the demultiplexer and the corresponding second WSS11a.
[0077] In some other embodiments, the second WSS11a can be replaced by a 1×N port-level SW, which includes a first port and multiple second ports. At any given time, the first port of the SW is only connected to one of the multiple second ports of the SW, and optical signals can be transmitted between the interconnected first and second ports. When the tributary-side switching unit 11 uses an SW, the tributary-side switching unit 11 can achieve port-level optical signal scheduling.
[0078] For example, in Figure 1 In this configuration, each line-side switching unit 12 in the first switching unit group 10a is also connected to each tributary-side switching unit 11 in the second switching unit group 10b. In other words, each tributary-side switching unit 11 is connected to each line-side switching unit 12 in all switching unit groups. Here, the line-side switching unit 12 and the tributary-side switching unit 11 can be connected via optical fiber.
[0079] Optionally, the number of branch ports of the first WSS can be greater than or equal to X*k+1. Where X equals the number of tributary-side switching units 11 in each switching unit group, k equals the number of switching unit groups in the optical switching node, and * represents multiplication. To save costs, the number of branch ports of the first WSS can be equal to X*k+1. For Figure 1 In the illustrated embodiment, X equals 2 and k equals 2, therefore, the number of branch ports of the first WSS is 5. In related technologies, when X equals 2 and k equals 2, the number of branch ports of the first WSS is 12.
[0080] When X equals 2 and k equals 4, if the structure of each exchange unit group adopts... Figure 1 In the structure shown, the number of branch ports of the first WSS is equal to 9. However, in related technologies, when X equals 2 and k equals 4, the number of branch ports of the first WSS is 24.
[0081] When X equals 2 and k equals 6, if the structure of each switching unit group adopts... Figure 1In the structure shown, the number of branch ports of the first WSS is 13. However, in related technologies, when X equals 2 and k equals 6, the number of branch ports of the first WSS is 36.
[0082] It is evident that the more optical switching nodes a system has, the more dimensions it contains. Consequently, the number of branch ports of each first WSS in this embodiment is reduced more significantly compared to the number of branch ports of the first WSS in related technologies.
[0083] Optionally, the number of branch ports of the second WSS11a can be greater than or equal to Y*k. Here, Y represents the number of line-side switching units 12 in each switching unit group, k equals the number of switching unit groups in the optical switching node, and * represents multiplication. To save costs, the number of branch ports of the second WSS11a can be equal to Y*k. Figure 1 In the embodiment shown, Y equals 4 and k equals 2, therefore, the number of branch ports of the second WSS11a is equal to 8.
[0084] Optionally, the first optical cross-connect device 21 is an N×N WSS or an N×N SW. The first optical cross-connect device 21 includes N first ports and N second ports. Wherein, N is an integer and N is greater than 1. Each first port of the first optical cross-connect device 21 is connected to one port of each line-side optical switching unit 12, and each second port of the first optical cross-connect device 21 is connected to one port of each line-side optical switching unit 12.
[0085] When the first optical cross-connect device 21 is an N×N WSS, it can transmit a single-wavelength optical signal consisting of any combination of wavelengths from a multi-wavelength optical signal received at any first port to any second port output, thereby achieving wavelength-level optical signal scheduling. When the first optical cross-connect device 21 is an N×N SW, each first port can only connect to one second port at any given time, and different first ports are connected to different second ports. Thus, by controlling the connection state between the first and second ports of the N×N WSS, a multi-wavelength optical signal received at any first port can be transmitted to any second port output, thereby achieving port-level optical signal scheduling. The multi-wavelength optical signal includes one or more single-wavelength optical signals.
[0086] For the first optical cross-connect device 21, N is greater than or equal to Y*k. Since the cost of N×N WSS and N×N SW is positively correlated with the value of N, the larger N is, the higher the cost of N×N WSS and N×N SW. Therefore, in implementation, N can be equal to Y*k. Figure 1 In the example shown, Y equals 4, k equals 2, therefore, N equals 8.
[0087] exist Figure 2 In the diagram, the arrow between any two components represents two optical fibers.
[0088] It should be noted that the embodiments of this application do not limit the number of line-side switching units 12 and branch-side switching units 11 included in the switching unit group, and can be set according to actual needs. Figure 2 An example was given where each switching unit group includes four line-side switching units 12 and two tributary-side switching units 11. However, in other embodiments, the switching unit group may also include two line-side switching units 12 and one tributary-side switching unit 11, or three line-side switching units 12 and two tributary-side switching units 11, etc. Furthermore, for each line-side switching unit in the same switching unit group, each line-side switching unit is connected to a pair of fiber optic links. The number of line-side switching units connected to backup links can also be set as needed. For example, the number of line-side switching units connected to backup links can be less than the number of line-side switching units connected to primary links, and the number of line-side switching units connected to backup links can even be zero.
[0089] Figure 3 This is a schematic diagram of the structure of an optical switching node provided in an embodiment of this application. Figure 2 The difference in the illustrated embodiment is that, Figure 3 The optical switching node also includes a second optical cross-connect device 22, and each line-side switching unit 12 is also connected to the second optical cross-connect device 22. The second optical cross-connect device 22 is a backup optical cross-connect device for the first optical cross-connect device 21.
[0090] The first optical cross-connect device 21 serves as the hub for optical signal exchange among multiple line-side switching units 12. If the first optical cross-connect device 21 fails, it will affect the optical signal exchange between the various line-side switching units 12. In this case, the second optical cross-connect device 22 can be used to achieve optical signal exchange between the various line-side switching units 12, improving the reliability of data transmission at the optical switching node.
[0091] Optionally, the second optical crossover device 22 can be an N×N optical switch, or an N×N WSS. The value of N is the same as that of the first optical crossover device 22.
[0092] exist Figure 3 In the illustrated embodiment, the number of branch ports of the first WSS in the line-side switching unit 12 can be equal to X*k+2. That is, compared to... Figure 2 The first WSS has one more branch port than the second optical crossover device 22.
[0093] For ease of illustration, Figure 3The connection line between a branch-side switching unit 11 in one switching unit group and a line-side switching unit 12 in another switching unit group is not shown in the diagram. This connection line can be found in [reference needed]. Figure 2 .
[0094] Figure 4 This is a schematic diagram of another optical switching node provided in an embodiment of this application. Figure 3 The difference in the illustrated embodiment is that, Figure 4 In this configuration, each branch-side switching unit 11 is connected to the first optical cross-connect device 21 and the second optical cross-connect device 22, respectively, instead of being connected to each line-side switching unit 12.
[0095] The first optical cross-connect device 21 is also used to transmit the local optical signal output from any branch-side switching unit 11 to any line-side switching unit connected to the first optical cross-connect device 21, and to transmit the line-side optical signal output from any line-side switching unit 12 connected to the first optical cross-connect device 21 to any branch-side switching unit 11. The second optical cross-connect device 22 is also used to transmit the local optical signal output from any branch-side switching unit 11 to any line-side switching unit 12 connected to the second optical cross-connect device 22, and to transmit the line-side optical signal output from any line-side switching unit 12 connected to the second optical cross-connect device 22 to any branch-side switching unit 11.
[0096] In this configuration, each line-side switching unit 12 is connected to each tributary-side switching unit 11, the first optical cross-connect device 21, and the second optical cross-connect device 22 within the same switching unit group. Correspondingly, the number of branch ports of the first WSS can be greater than or equal to X+2, where X equals the number of tributary-side switching units in each switching unit group. Figure 4 In the illustrated embodiment, X equals 2, therefore, the number of branch ports of the first WSS is equal to 4.
[0097] It should be noted that, Figure 2 The illustrated embodiment can also be used Figure 4 A similar connection method is used, in which the number of branch ports of the first WSS is greater than or equal to X+1. To save costs, the number of branch ports of the first WSS can be equal to X+1.
[0098] Each branch-side switching unit 11 is connected to each line-side switching unit 12, the first optical cross-connect device 21, and the second optical cross-connect device 22 in the same switching unit group. Correspondingly, the number of branch ports of the second WSS can be greater than or equal to Y+2, where Y represents the number of line-side switching units in each switching unit group. Figure 4 In the illustrated embodiment, Y equals 4, therefore, the number of branch ports of the second WSS is equal to 6.
[0099] The first optical cross-connect device 21 is connected to each line-side switching unit 12 and each tributary-side switching unit 11, respectively. Therefore, when the first optical cross-connect device adopts an N×N WSS or an N×N port-level SW, N is greater than or equal to Y*k+X*k. For example, N is equal to Y*k+X*k.
[0100] In practical applications, the number of line-side switching units 12 is typically much greater than two. If each tributary-side switching unit 11 needs to be connected to each line-side switching unit 12 separately, this would simultaneously increase the number of ports in both line-side switching units 12 and tributary-side switching units 11, as well as the number of fiber connections between them. In this embodiment, the number of ports in both line-side switching units 12 and tributary-side switching units 11 is significantly reduced. Furthermore, the number of ports in each line-side switching unit 12 and tributary-side switching unit 11 is only related to the number of line-side switching units and tributary-side switching units within the switching unit group, and does not increase with the increase in the number of switching unit groups.
[0101] Figure 5 This is a schematic diagram of the structure of an optical switching node provided in an embodiment of this application. Figure 3 The difference in the illustrated embodiment is that, Figure 3 In this configuration, all line-side switching units in each switching unit group are connected to the first optical cross-connect device 21, while... Figure 5 In the embodiment shown, in each switching unit group, a portion of the line-side switching units are connected to the first optical cross-connect device 21, and another portion of the line-side switching units are connected to the third cross-connect device 23.
[0102] like Figure 5 As shown, the optical switching node includes a first optical cross-connect device 21, a third optical cross-connect unit 23, and two switching unit groups. The two switching unit groups are the first switching unit group 10a and the second switching unit group 10b. Each switching unit group includes two branch-side switching units 11 and four line-side switching units 12, with each branch-side switching unit 11 in the same switching unit group connected to each line-side switching unit 12.
[0103] Each switching unit group comprises four line-side switching units 12, including two first line-side switching units and two second line-side switching units. The two first line-side switching units are respectively connected to a first optical cross-connect device 21, and the two second line-side switching units are respectively connected to a third optical cross-connect device 21. The first optical cross-connect device 21 is used to transmit the optical signal output from any first line-side switching unit 12 in the first switching unit group 10a to any first line-side switching unit 12 in the second switching unit group 10b; or, to transmit the optical signal output from any first line-side switching unit 12 in the second switching unit group 10b to any first line-side switching unit 12 in the second switching unit group 10b. The third optical cross-connect device 23 is used to transmit the optical signal output from any second line-side switching unit 12 in the first switching unit group 10a to any second line-side switching unit 12 in the second switching unit group 10b; or, to transmit the optical signal output from any second line-side switching unit 12 in the second switching unit group 10b to any second line-side switching unit 12 in the second switching unit group 10b.
[0104] Optionally, the optical fiber link connected to the first line-side switching unit is the primary link, and the optical fiber link connected to the second line-side switching unit is the backup link. In this way, signal pass-through between the first line-side switching units of different switching unit groups can be achieved through the first optical cross-connect device 21, and signal pass-through between the second line-side switching units of different switching unit groups can be achieved through the third optical cross-connect device 23.
[0105] Optionally, the third optical cross-connect device 23 can be an N×N port-level switch (SW) or an N×N optical switch (WSS). Here, N is greater than or equal to half of Y*K. For example, Figure 5 In this case, N equals 4.
[0106] In this embodiment, in each line-side switching unit, the number of branch ports of the first WSS is related to... Figure 2 The number of branch ports of the first WSS is the same; in each branch-side switching unit, the number of branch ports of the second WSS is the same as... Figure 2 The number of branch ports in the second WSS is the same.
[0107] In this embodiment, the value of N corresponding to the first optical cross-connect device 21 and the third optical cross-connect device 23 is relatively small, that is, the number of ports is relatively small, which is beneficial to reducing the cost of the first optical cross-connect device 21 and the third optical cross-connect device 23.
[0108] Figure 6 This is a schematic diagram of another optical switching node provided in an embodiment of this application. Figure 5 The difference in the illustrated embodiment is that, Figure 6In this configuration, each tributary-side switching unit 11 is connected to the first optical cross-connect device 21 and the third optical cross-connect device 23, respectively, instead of being connected to each line-side switching unit 12. This saves on the number of ports in the tributary-side switching units 11.
[0109] The first optical cross-connect device 21 is also used to transmit the local optical signal output from any branch-side switching unit 11 to any line-side switching unit 12 connected to the first optical cross-connect device 21, and to transmit the line-side optical signal output from any line-side switching unit 12 connected to the first optical cross-connect device 21 to any branch-side switching unit 11. The third optical cross-connect device 23 is also used to transmit the local optical signal output from any branch-side switching unit 11 to any line-side switching unit 12 connected to the third optical cross-connect device 23, and to transmit the line-side optical signal output from any line-side switching unit 12 connected to the third optical cross-connect device to any branch-side switching unit 11.
[0110] In this embodiment, the number of ports in each line-side switching unit 12 and each tributary-side switching unit 11 is significantly reduced. Furthermore, the number of ports in each line-side switching unit 12 and each tributary-side switching unit 11 is only related to the number of line-side switching units and the number of tributary-side switching units within the switching unit group, and will not increase with the increase of the number of switching unit groups.
[0111] exist Figure 6 In the illustrated embodiment, the relevant content regarding the first WSS and the second WSS can be found in [reference needed]. Figure 4 The embodiments shown will not be described in detail here.
[0112] In the first possible implementation, Figure 6 The line-side switching units in the two switching unit groups correspond to different directions, for example, Figure 6 The optical switching node in the first switching unit group 10a is located in AZ1. The line-side switching unit in the first switching unit group 10a is connected to the optical switching node in AZ2 via an optical fiber link, which corresponds to the AZ2 direction. The line-side switching unit in the second switching unit group 10b is connected to the optical switching node in AZ3 via an optical fiber link, which corresponds to the AZ3 direction.
[0113] In the second possible implementation, Figure 6 The line-side switching units in the two switching unit groups correspond to the same direction, for example, Figure 6The optical switching node is located in AZ1. The line-side switching unit in the first switching unit group 10a is connected to the optical switching node in AZ2 through an optical fiber link. The line-side switching unit in the second switching unit group 10b is connected to the optical switching node in AZ2 through an optical fiber link. That is, the line-side switching unit in the first switching unit group 10a and the line-side switching unit in the second switching unit group 10b both correspond to the AZ2 direction.
[0114] In this second possible implementation, the two optical switching nodes are connected via two 4-fiber 3-routing planes, which further improves the reliability of data transmission between the optical switching nodes. Furthermore, the fiber links in the two 4-fiber 3-routing planes can be scheduled according to actual service transmission needs, achieving fiber link resource pooling. This avoids a situation where one 4-fiber 3-routing plane carries an excessively large service load while the other carries an insufficient load. Moreover, the two independent 4-fiber 3-routing planes are connected via the first optical cross-connect device 21 and the third optical cross-connect device 23, enabling the sharing of backup links between the two 4-fiber 3-routing planes.
[0115] Figure 7 This is a schematic diagram of another optical switching node provided in an embodiment of this application. Figure 6 The difference in the illustrated embodiment is that, Figure 6 In the illustrated embodiment, in each optical switching unit group, the number of first line-side switching units (i.e., line-side switching units 12 connected to the first optical cross-connect device 21) is equal to the number of second line-side switching units (i.e., line-side switching units 12 connected to the third optical cross-connect device 23), while... Figure 7 In the illustrated embodiment, the number of first line-side switching units in each optical switching unit group is greater than the number of second line-side switching units. For example, each optical switching unit group includes three line-side switching units, wherein the three line-side switching units include two first line-side switching units and one second line-side switching unit.
[0116] When two planes are arranged between two switching nodes, the number of line-side switching units connected to the backup links in each plane can be reduced because the backup links in the two planes can be shared. This reduces the number of backup links between the two optical switching nodes and thus reduces the cost of fiber leasing.
[0117] Optionally, in Figure 6 and Figure 7In the illustrated embodiment, the number of second line-side switching units 12 in each optical switching unit group is the same. In other embodiments, there may be two optical switching unit groups with different numbers of second line-side switching units. For example, the first optical switching unit group 10a includes one second line-side switching unit, and the second optical switching unit group 10b includes two second line-side switching units.
[0118] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The “multiple” mentioned in the embodiments of this application refers to two or more. A and / or B indicate three possibilities: A; B; and A and B.
[0119] The above is merely one embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An optical switching node, characterized in that, include: The first optical cross-connect device and M switching unit groups, where M is an integer and M is greater than 1; Each of the M switching unit groups includes at least one branch-side switching unit and at least one line-side switching unit, and each branch-side switching unit is connected to each line-side switching unit in the at least one line-side switching unit. The at least one line-side switching unit includes a first line-side switching unit, which is connected to the first optical cross-connect device. The first optical cross-connect device is used to transmit the optical signal output by the first line-side switching unit in the first switching unit group to the first line-side switching unit in the second switching unit group, and to transmit the optical signal output by the first line-side switching unit in the second switching unit group to the first line-side switching unit in the first switching unit group. The first switching unit group and the second switching unit group are any two switching unit groups among the M switching unit groups.
2. The optical switching node according to claim 1, characterized in that, The optical switching node also includes a second optical cross-connect device, and the first line-side switching unit is also connected to the second optical cross-connect device, which is a backup optical cross-connect device for the first optical cross-connect device.
3. The optical switching node according to claim 2, characterized in that, Each first line-side switching unit in each switching unit group is connected to the first optical cross-connect device and the second optical cross-connect device, respectively.
4. The optical switching node according to claim 1, characterized in that, The optical switching node further includes a third optical cross-connect device, and each of the at least two switching unit groups further includes a second line-side switching unit, which is connected to the third optical cross-connect device. The third optical cross-connect device is used to transmit the optical signal output by the second line-side switching unit in the first switching unit group to the second line-side switching unit in the second switching unit group; and to transmit the optical signal output by the second line-side switching unit in the second switching unit group to the second line-side switching unit in the first switching unit group.
5. The optical switching node according to claim 4, characterized in that, In each switching unit group, the number of first line-side switching units is greater than or equal to the number of second line-side switching units, wherein the first line-side switching units are used to connect to the main optical fiber link, and the second line-side switching units are used to connect to the backup optical fiber link.
6. The optical switching node according to claim 2 or 3, characterized in that, Each of the at least one branch-side switching units is connected to the first optical cross-connect device and the second optical cross-connect device, respectively. The first optical cross-connect device is also used to transmit the local optical signal output by any branch-side switching unit to any line-side switching unit connected to the first optical cross-connect device, and to transmit the line-side optical signal output by any line-side switching unit connected to the first optical cross-connect device to the any branch-side switching unit. The second optical cross-connect device is also used to transmit the local optical signal output by any branch-side switching unit to any line-side switching unit connected to the second optical cross-connect device, and to transmit the line-side optical signal output by any line-side switching unit connected to the second optical cross-connect device to the aforementioned branch-side switching unit.
7. The optical switching node according to claim 4 or 5, characterized in that, Each of the at least one branch-side switching units is connected to the first optical cross-connect device and the third optical cross-connect device, respectively. The first optical cross-connect device is also used to transmit the local optical signal output by any branch-side switching unit to any line-side switching unit connected to the first optical cross-connect device, and to transmit the line-side optical signal output by any line-side switching unit connected to the first optical cross-connect device to the any branch-side switching unit. The third optical cross-connect device is also used to transmit the local optical signal output by any branch-side switching unit to any line-side switching unit connected to the third optical cross-connect device, and to transmit the line-side optical signal output by any line-side switching unit connected to the third optical cross-connect device to the any branch-side switching unit.
8. The optical switching node according to any one of claims 1 to 5, characterized in that, Each branch-side switching unit in each switching unit group is connected to each line-side switching unit in other switching unit groups.
9. The optical switching node according to any one of claims 1 to 8, characterized in that, The first switching unit group and the second switching unit group correspond to different directions; or, the first switching unit group and the second switching unit group correspond to the same direction.
10. The optical switching node according to any one of claims 1 to 9, characterized in that, The first optical crossover device is a wavelength selective switch or an optical switch.
11. The optical switching node according to claim 2, 3, or 6, characterized in that, The second optical crossover device is a wavelength selective switch or a port-level optical switch.
12. The optical switching node according to any one of claims 4-5 and 7, characterized in that, The third optical crossover device is a wavelength selective switch or a port-level optical switch.
13. The optical switching node according to any one of claims 1 to 12, characterized in that, The line-side switching unit includes a 1×N wavelength selection switch, a 1×N port-level optical switch, or a 1×N coupler.
14. The optical switching node according to any one of claims 1 to 13, characterized in that, The branch-side switching unit includes a 1×N wavelength selective switch or a 1×N port-level optical switch.
15. An optical communication system, characterized in that, It includes multiple optical switching nodes, wherein a first optical switching node among the multiple optical switching nodes is connected to at least two other optical switching nodes besides the first optical switching node, and the first optical switching node is the optical switching node according to any one of claims 1 to 14.