Reconfigurable optical add-drop multiplexer node

Abstract

A ROADM node includes D splitters, D sets of first wavelength selective switches (WSSs), D sets of second WSSs, and D combiners. A set of first WSSs includes N first WSSs, and a set of second WSSs includes N second WSSs. A common port of the splitters is coupled to a first optical fiber, and N branch ports of the splitters are respectively coupled to common ports of the N first WSSs in the set of first WSSs. At least some of K branch ports of the first WSSs are respectively coupled to a plurality of second WSSs, and at least some of K branch ports of the second WSSs are respectively coupled to a plurality of first WSSs. A common port of the combiners is coupled to a second optical fiber, and N branch ports of the combiners are respectively coupled to common ports of the N second WSSs in the set of second WSSs.

Description

Technical Field

[0001] This invention relates to the field of optical communication, and more particularly to a reconfigurable optical add-drop multiplexer (ROADM) node. Background Technology

[0002] Currently, in optical networks, ROADM nodes are used to perform various functions on light beams of different wavelengths. For example, ROADM nodes can insert, split, and redirect light beams of specific wavelengths.

[0003] Typically, the degree of a ROADM node is defined as the total number of fiber pairs (including input and output fibers) connected to the ROADM node. Because the capacity of a single fiber is limited, network operators add more fibers to their networks as traffic increases. With the deployment of new fibers, the degree of the ROADM node also needs to increase accordingly. Summary of the Invention

[0004] An embodiment of the present invention provides a ROADM node to solve the problem of degree expansion.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A ROADM node includes D splitters, D groups of first wavelength select switches (WSS), D groups of second WSS, and D combiners. Each splitter has a common port and N tributary ports. Each group of first WSS comprises N first WSSs, each of which has a common port and K tributary ports. Each group of second WSS comprises N second WSSs, each of which has a common port and K tributary ports. Each combiner has a common port and N tributary ports. The common port of each splitter is used to couple to a first optical fiber, and the N tributary ports of each splitter are respectively coupled to the common port of the N first WSSs in the group of first WSS. At least a portion of the K tributary ports of the first WSSs are respectively coupled to tributary ports of a plurality of the second WSSs in the D groups of second WSS, and at least a portion of the K tributary ports of the second WSSs are respectively coupled to tributary ports of the plurality of first WSSs in the D groups of first WSS. The common port of the combiner is used to couple to the second optical fiber, and the N branch ports of the combiner are respectively coupled to the common port of the N second WSSs in the group of second WSSs. K is greater than the quotient obtained by dividing D by N (K>D / N), N is greater than or equal to 2 (N≥2), and D, N, K, and D / N are all positive integers.

[0007] In the aforementioned ROADM node, the first-level splitter, the second-level first WSS, the third-level second WSS, and the fourth-level combiner together constitute a four-level architecture. A first fiber of degree (direction) is coupled to N first WSSs in a group of first WSSs via a splitter. These N first WSSs are then coupled to second WSSs in different groups of second WSSs within a group of D second WSSs. Finally, N second WSSs in a group of second WSSs are coupled to the second fiber of the same degree via a combiner. Thus, by combining different types of splitters and combiners, and different sizes of WSSs, flexible coupling of a first fiber of degree to second fibers of multiple degrees can be achieved. Since N first WSSs are coupled to a splitter and N second WSSs are coupled to a combiner, this scheme can achieve multiple degrees compared to a scheme that couples only one WSS per degree, and it has the ability to expand to higher degrees.

[0008] In some embodiments, the first set of WSSs and the second set of WSSs are fully connected. This allows the wavelengths received by the first fiber of any degree to be distributed to the second fiber of any degree during signal transmission from the first fiber to the second fiber, thereby achieving a mesh connection and enabling ROADM nodes to be colorless and directionless.

[0009] In some embodiments, the D groups of second WSSs include N clusters, and each cluster includes D / N groups of second WSSs. The D / N branch ports of each first WSS in a group of first WSSs are coupled one-to-one to the branch ports of the D / N second WSSs corresponding to each first WSS in the j-th cluster. Any two of the D / N second WSSs in the j-th cluster are located in different groups of second WSSs; j is a positive integer greater than or equal to 1 and less than or equal to N (1≤j≤N). Since the D / N branch ports of each first WSS in a group of first WSSs are coupled one-to-one to the branch ports of the D / N second WSSs in the corresponding cluster, and the D / N second WSSs in the cluster are located in D / N groups of second WSSs, the group of first WSSs can be connected to the second WSSs in every direction, thereby achieving full connectivity.

[0010] In some embodiments, the group of second WSSs is fully connected to the group of first WSSs. Thus, during the transmission of signals from the first fiber to the second fiber, the second fiber of any degree can receive wavelengths transmitted by the first fiber of all degrees, thereby achieving a mesh connection and enabling ROADM nodes to have colorless and directionless capabilities.

[0011] In some embodiments, the first D groups of WSSs include N clusters, and each cluster includes D / N groups of first WSSs. Each of the D / N branch ports of each second WSS in the group of second WSSs is correspondingly coupled to the D / N branch ports of the first WSSs corresponding to each second WSS in the i-th cluster, and any two of the D / N first WSSs in the i-th cluster are located in different groups of first WSSs; i is a positive integer greater than or equal to 1 and less than or equal to N (1 ≤ i ≤ N). Since each of the D / N branch ports of each second WSS in the group of second WSSs is correspondingly coupled to the D / N branch ports of the first WSSs in the corresponding cluster, and the D / N first WSSs in the cluster are respectively located in D / N groups of first WSSs, the group of second WSSs can be connected to the first WSSs in each direction, thereby achieving full connection.

[0012] In some embodiments, K is greater than or equal to 16 (K ≥ 16). In this way, fewer splitters, combiners, and WSSs can be used to obtain a higher degree.

[0013] In some embodiments, D = N×(K–S'), where K represents the number of branch ports of the first WSSs coupled to the second WSSs; S' represents the number of branch ports of the first WSSs different from the branch ports coupled to the second WSSs, and S' is a positive integer less than K (S' < K). The branch ports of the first WSSs different from the branch ports coupled to the second WSSs include branch ports for add / drop and other branch ports except for the branch ports for add / drop and the branch ports coupled to the second WSSs. For example, D is equal to 60 (D = 60), N is equal to 2 (N = 2), and K is equal to 32 (K = 32); or D is equal to 120 (D = 120), N is equal to 2 (N = 2), and K is equal to 64 (K = 64); or D is equal to 120 (D = 120), N is equal to 4 (N = 4), and K is equal to 32 (K = 32). Through these combinations, the optical configuration of the node can be achieved.

[0014] In some embodiments, the splitter is a WSS. In this way, a WSS can be used as a splitter.

[0015] In some embodiments, the combiner is a WSS. In this way, a WSS can be used as a combiner.

[0016] In some embodiments, the ROADM node includes multiple line card frames, and each line card frame includes multiple line cards. The line cards include the first WSSs in the D groups of first WSSs and / or the second WSSs in the D groups of second WSSs. In this way, traditional frames can be used to accommodate the components in the ROADM node.

[0017] In some embodiments, the line card includes a first WSS, a second WSS, and one of the D splitters; or, the line card includes a first WSS, a second WSS, and one of the D combiners; or, the line card includes two first WSSs, two second WSSs, one of the D splitters, and one of the D combiners; or, the line card includes two first WSSs and one of the D splitters; or, the line card includes two second WSSs and one of the D combiners. This allows for flexible design of line cards in a line card chassis.

[0018] In some embodiments, the ROADM node further includes at least one add-drop component, and the at least one add-drop component is coupled to S branch ports of the first WSS; S is less than K (S < K), and S is a positive integer. In the first WSS, the S branch ports coupled to the at least one add-drop component are different from the branch ports coupled to the second WSS. By adding add-drop components, the ROADM node can flexibly add and drop wavelengths.

[0019] In some embodiments, the ROADM node further includes at least one add-drop component, and the at least one add-drop component is coupled to T branch ports of the second WSS; T is less than K (T < K), and T is a positive integer. In the second WSS, the T branch ports coupled to the at least one add-drop component are different from the branch ports coupled to the first WSS. By adding add-drop components, the ROADM node can flexibly add and drop wavelengths.

[0020] In some embodiments, the add-drop component in the at least one add-drop component includes D' third WSSs and K add-drop cards, and each of the D' third WSSs has a common port and K branch ports; D' is a positive integer. The common ports of the D' third WSSs are respectively coupled to D' branch ports of multiple first WSSs or multiple second WSSs, and the K branch ports of the third WSSs are respectively coupled to the K add-drop cards. With such an arrangement, the first WSS or the second WSS coupled to the D' third WSSs can simultaneously drop or add wavelengths.

[0021] In some embodiments, D' is equal to D (D' = D); the common ports of the D third WSSs in the add-drop component are coupled to D branch ports of D first WSSs or D second WSSs. With such an arrangement, the configuration of the node can be further optimized because all wavelengths can be dropped from D first optical fibers or added to D second optical fibers.

[0022] In some embodiments, for the at least one add-drop component coupled to the S branch ports of the first WSS, the at least one add-drop component includes M add-drop components, where M is a positive integer greater than or equal to 2 and less than or equal to N×S (2 ≤ M ≤ N×S); the D first WSSs coupled to the D third WSSs in the add-drop components are respectively located in the D groups of first WSSs, and the first WSSs in each group of first WSSs are coupled to different add-drop components. For the at least one add-drop component coupled to the T branch ports of the second WSS, the at least one add-drop component includes M' add-drop components, where M' is a positive integer greater than or equal to 2 and less than or equal to N×T (2 ≤ M' ≤ N×T); the D second WSSs coupled to the D third WSSs in the add-drop components are respectively located in the D groups of second WSSs, and the second WSSs in each group of second WSSs are coupled to different add-drop components. In this way, each add-drop component can add and drop wavelengths at all degrees.

[0023] In some embodiments, the add-drop card in the K add-drop cards includes an add-drop module having Q input ports and P output ports, and multiple fourth WSSs each having a common port and U branch ports; the common port of each fourth WSS is coupled to one of the Q input ports of the add-drop module, and the U branch ports of the fourth WSS are respectively coupled to U third WSSs among the D' third WSSs in the add-drop component; U is less than D' (U < D'), and U, P, and Q are all positive integers. The P output ports of the add-drop module are used to add or drop wavelengths. By combining the add-drop module and multiple fourth WSSs to obtain an add-drop card, the add-drop component can be colorless, non-directional, and non-competitive.

[0024] In some embodiments, the add-drop card in the K add-drop cards includes an add-drop module having Q' input ports and P output ports, and at least some of the Q' input ports of the add-drop module are correspondingly coupled to the D' third WSSs in the add-drop component one by one; Q' is greater than or equal to D' (Q' ≥ D'), and P and Q' are both positive integers. The P output ports of the add-drop module are used to add or drop wavelengths. In this way, a colorless and non-directional add-drop component can be adopted.

[0025] In some embodiments, the ROADM node includes at least one WSS chassis and at least one add-drop card chassis corresponding to each add-drop component. The D' third WSSs in the add-drop component are installed in the at least one WSS chassis, and the K add-drop cards in the add-drop component are installed in the at least one add-drop card chassis. By using different chassis to separately place the third WSS and the add-drop card in the add-drop component, it is convenient to connect the third WSS and the add-drop card.

[0026] In some embodiments, the ROADM node includes at least one plug-in card chassis corresponding to each plug-in assembly, the plug-in card chassis including a middle plate and slots located on both sides of the middle plate. At least a portion of the D' third WSSs in the plug-in assembly are mounted in the slots located on one side of the middle plate, and at least a portion of the K plug-in cards in the plug-in assembly are mounted in slots located on the other side of the middle plate. By using a large chassis to house the third WSSs and plug-in cards in the plug-in assembly, the number of chassis used can be reduced. Attached Figure Description

[0027] Figure 1 A schematic diagram of the chassis of a 16-degree ROADM node provided in an embodiment of the present invention; Figure 2 To show Figure 1 The diagram shows the connection of the WSS in the line card of the ROADM node; Figure 3 A schematic diagram of the line portion of a ROADM node provided in an embodiment of the present invention; Figure 4 A schematic diagram of the line portion of another ROADM node provided in an embodiment of the present invention; Figure 5 A schematic diagram of the line portion of another ROADM node provided in an embodiment of the present invention; Figure 6 A schematic diagram of the line portion of another ROADM node provided in an embodiment of the present invention; Figure 7 A schematic diagram of the line portion of another ROADM node provided in an embodiment of the present invention; Figures 8A to 8D A schematic diagram of the line portion of another ROADM node provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the chassis corresponding to the circuit section provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of another chassis corresponding to the circuit section provided in an embodiment of the present invention; Figure 11 A schematic diagram of the insertion / extraction assembly provided in an embodiment of the present invention; Figure 12 A schematic diagram of another plug-in component provided in an embodiment of the present invention; Figure 13 This is a schematic diagram of the chassis corresponding to the plug-in assembly provided in an embodiment of the present invention; Figure 14 This is a schematic diagram of a chassis corresponding to another plug-in assembly provided in an embodiment of the present invention; Figure 15This is a schematic diagram of another chassis corresponding to the plug-in assembly provided in an embodiment of the present invention; Figure 16 This is a schematic diagram of another chassis corresponding to another plug-in assembly, provided in an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention should be included within the protection scope of the present invention.

[0029] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as having an open and inclusive meaning, that is, "including, but not limited to." In the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with one or more embodiments or examples is included in at least one embodiment or example of the invention. The illustrative representations of the above terms do not necessarily refer to the same one or more embodiments or examples. Furthermore, a particular feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0030] In the following text, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined by "first" or "second" may explicitly or implicitly include one or more of these features. In the description of embodiments of the invention, unless otherwise stated, the terms "a plurality of" and "multiple" mean two or more.

[0031] Orientational terms such as “up,” “down,” “left,” “right,” “horizontal,” and “vertical” are defined relative to the indicated position of the components in the diagram. It should be understood that these orientational terms are relative concepts that can be used for relative description and clarification, and they may change accordingly if the orientation of the components in the diagram changes.

[0032] In the description of some embodiments, the terms "coupled" and "connected" and their derivatives may be used. For example, the term "connected" may be used in the description of some embodiments to indicate that two or more components are in direct physical or electrical contact with each other. As another example, the term "coupled" may be used in the description of some embodiments to indicate that two or more components are in direct physical or electrical contact with each other. However, the term "coupled" may also refer to two or more components that are not in direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content herein.

[0033] The phrase “A and / or B” includes the following three combinations: A only; B only; and a combination of A and B.

[0034] ROADM can be used in systems employing wavelength division multiplexing (WDM), which allow wavelength-modulated data traffic to be inserted at the source node, then passed through one or more ROADM nodes, after which the data traffic is split at the destination node. Once split, the destination node demodulates the light and decodes the data into electronic bits.

[0035] ROADM nodes play a crucial role in the exchange and transmission of large volumes of data. A ROADM node has two parameters: the number of directions (i.e., degrees) and the number of wavelengths that can be inserted or split.

[0036] Currently, due to the size of the key component in ROADM node design (i.e., the wavelength select switch (WSS)), ROADM nodes can provide 8 or 16 degrees (i.e., the number of directions).

[0037] In the example where the degree of the ROADM node is 16, such as Figure 1 As shown, the chassis 10 may include 32 slots 101 for inserting multiple line cards 102 and multiple dropout cards 103. Each slot 101 can be interconnected with other slots 101 via an optical backplane. The line card 102 performs line functions as it can interconnect with other ROADM nodes. Each line card 102 can connect to one fiber pair and can occupy a single slot in the chassis 10. The dropout card 103 processes split or inserted wavelengths and can occupy two slots 101.

[0038] Line card 102 may include two WSS, among which Figure 2The diagram illustrates the WSS connections in 16 line cards 102. Additionally, line card 102 may also include filters, two erbium-doped fiber amplifiers (EDFAs), and circuitry for the optical service channel (OSC). Add-drop card 103 may include an add-in module and an add-out module, each module including 24 add-drop ports, allowing up to 24 wavelengths to be added or added at the ROADM node.

[0039] As traffic increases (i.e., the demand for network capacity increases), there is a need for ROADMs with higher height numbers to allow transmission in many different directions and to provide the corresponding flexibility.

[0040] Based on this situation, embodiments of the present invention provide a ROADM node. For example... Figures 3 to 8D As shown, ROADM node 20 includes D splitters 201, D groups of first wavelength select switches (WSS) 202, D groups of second WSSs 203, and D combiners 204. Each splitter 201 has a common port 2011 and N tributary ports 2012. Each group of first WSSs 202 includes N first WSSs 202, where each first WSS 202 has a common port 2021 and K tributary ports 2022. Each group of second WSSs 203 includes N second WSSs 203, where each second WSS 203 has a common port 2031 and K tributary ports 2032. Each combiner 204 has a common port 2041 and N tributary ports 2042. K is greater than the quotient of D divided by N (K>D / N), N is greater than or equal to 2 (N≥2), and D, N, K, and D / N are all positive integers.

[0041] The common port 2011 of the splitter 201 is used to couple to the first optical fiber 31, and the N branch ports 2012 of the splitter 201 are respectively coupled to the common port 2021 of the N first WSS 202 in the group of first WSS 202.

[0042] The common port 2041 of the combiner 204 is used to couple to the second optical fiber 32, and the N branch ports 2042 of the combiner 204 are respectively coupled to the common port 2031 of the N second WSS 203 in the group of second WSS 203.

[0043] At least a portion of the K branch ports 2022 of the first WSS 202 are respectively coupled to a plurality of branch ports 2032 of the second WSS 203 in the D group, and at least a portion of the K branch ports 2032 of the second WSS 203 are respectively coupled to a plurality of branch ports 2022 of the first WSS 202 in the D group.

[0044] It should be understood that for at least a portion of the K tributary ports 2022 of the first WSS 202, each tributary port 2022 is coupled to a tributary port 2032 of the second WSS 203; and for at least a portion of the K tributary ports 2032 of the second WSS 203, each tributary port 2032 is coupled to a tributary port 2022 of the first WSS 202. Additionally, Figure 3 The following scenario is illustrated: a set of first WSS 202 in one direction (degrees) can be coupled to second WSS 203 in all directions, or can be coupled to second WSS 203 in some directions (i.e., Figure 3 (Provides partial connection), while Figures 4 to 8D Provides full connectivity.

[0045] refer to Figure 3Taking two first WSS 202s in the first direction (degrees) as an example, the first branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the first direction; the second branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the second direction; the third branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the third direction; the fourth branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the fourth direction; and so on...; the 16th branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 16th direction. The first branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in the 17th direction; the second branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in the 18th direction; the third branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in the 19th direction; the fourth branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in the 20th direction; and so on...; the 16th branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in the 32nd direction.

[0046] refer to Figure 3Taking two first WSS 202s in the 15th direction (degrees) as an example, the first branch port 2022 of the upper first WSS 202 can be coupled to the 15th branch port 2032 of the upper second WSS 203 in the first direction; the second branch port 2022 of the upper first WSS 202 can be coupled to the 15th branch port 2032 of the upper second WSS 203 in the second direction; the third branch port 2022 of the upper first WSS 202 can be coupled to the 15th branch port 2032 of the upper second WSS 203 in the third direction; the fourth branch port 2022 of the upper first WSS 202 can be coupled to the 15th branch port 2032 of the upper second WSS 203 in the fourth direction; and so on...; the 15th branch port 2022 of the upper first WSS 202 can be coupled to the 15th branch port 2032 of the upper second WSS 203 in the 15th direction. It should be noted that the 16th branch port 2022 of the upper first WSS202 may not be coupled to the second WSS 203. The first branch port 2022 of the lower first WSS 202 can be coupled to the 15th branch port 2032 of the lower second WSS 203 in the 17th direction; the second branch port 2022 of the lower first WSS 202 can be coupled to the 15th branch port 2032 of the lower second WSS 203 in the 18th direction; the third branch port 2022 of the lower first WSS 202 can be coupled to the 15th branch port 2032 of the lower second WSS 203 in the 19th direction; the fourth branch port 2022 of the lower first WSS 202 can be coupled to the 15th branch port 2032 of the lower second WSS 203 in the 20th direction; and so on...; the 16th branch port 2022 of the lower first WSS 202 can be coupled to the 15th branch port 2032 of the lower second WSS 203 in the 32nd direction.

[0047] refer to Figure 3Taking the two first WSSs 202 in the 16th direction (degrees) as an example, the first branch port 2022 of the upper first WSS 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the first direction; the third branch port 2022 of the upper first WSS 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the third direction; the fifth branch port 2022 of the upper first WSS 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the fifth direction; the seventh branch port 2022 of the upper first WSS 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the seventh direction; the ninth branch port 2022 of the upper first WSS 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the ninth direction; and so on...; the upper first WSS The 15th branch port 2022 of 202 can be coupled to the 16th branch port 2032 of the upper second WSS 203 in the 15th direction. It should be noted that the 2nd, 4th, 6th, 8th, 10th, 12th, 14th and 16th branch ports 2022 of the upper first WSS 202 can be uncoupled to the second WSS 203. The first branch port 2022 of the lower first WSS 202 can be coupled to the 16th branch port 2032 of the lower second WSS 203 in the 17th direction; the second branch port 2022 of the lower first WSS 202 can be coupled to the 16th branch port 2032 of the lower second WSS 203 in the 18th direction; the third branch port 2022 of the lower first WSS 202 can be coupled to the 16th branch port 2032 of the lower second WSS 203 in the 19th direction; the fourth branch port 2022 of the lower first WSS 202 can be coupled to the 16th branch port 2032 of the lower second WSS 203 in the 20th direction; and so on...; the 16th branch port 2022 of the lower first WSS 202 can be coupled to the 16th branch port 2032 of the lower second WSS 203 in the 32nd direction.

[0048] refer to Figure 3Taking the two first WSS 202s in the 17th direction (degrees) as an example, the first branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 17th direction; the second branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 18th direction; the third branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 19th direction; the fourth branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 20th direction; and so on...; the 16th branch port 2022 of the upper first WSS 202 can be coupled to the first branch port 2032 of the upper second WSS 203 in the 32nd direction. The first branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in a first direction; the third branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in a third direction; the fifth branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in a fifth direction; the seventh branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in a seventh direction; the ninth branch port 2022 of the lower first WSS 202 can be coupled to the first branch port 2032 of the lower second WSS 203 in a ninth direction; and so on...; the fifteenth branch port 2022 of the lower first WSS 202 can be coupled to the lower second WSS in a fifteenth direction. The first branch port 2032 of 203. It should be noted that the second, fourth, sixth, eighth, tenth, twelfth, fourteenth and sixteenth branch ports 2022 of the lower first WSS 202 may not be coupled to the second WSS 203.

[0049] For example, the first WSS 202 of group D and the second WSS 203 of group D can be coupled through an optical backplane.

[0050] In an embodiment of the present invention, D splitters 201, D groups of first WSSs 202, D groups of second WSSs 203, and D combiners 204 together constitute a four-level architecture. The D splitters 201 are at the first level, the D groups of first WSSs 202 are at the second level, the D groups of second WSSs 203 are at the third level, and the D groups of combiners 204 are at the fourth level. The splitters at the first level are 1×N splitters, the first WSS at the second level is 1×K WSS, the second WSS at the third level is K×1 WSS, and the combiners at the fourth level are N×1 combiners. It can be seen that the four-level architecture is a symmetrical architecture.

[0051] For example, the first optical fiber 31 is the input optical fiber, and the second optical fiber 32 is the output optical fiber; or, the second optical fiber 32 is the input optical fiber, and the first optical fiber 31 is the output optical fiber. For ease of description, the following embodiments are described using the example of the first optical fiber 31 as the input optical fiber and the second optical fiber 32 as the output optical fiber. The first optical fiber 31 and the second optical fiber 32 can be single-mode fiber (SMF) or multi-core fiber (MCF).

[0052] The N 1×K WSSs of the second stage coupled to the first-stage splitter (i.e., a set of first WSSs 202) and the N K×1 WSSs of the third stage coupled to the corresponding combiner of the fourth stage (i.e., a set of second WSSs 203) form one of the multiple directions of the ROADM structure. For example, the ROADM node also includes a controller that manages the N first WSSs 202 in one direction to ensure that the same wavelength is not sent to the branch port 2042 of the combiner 204.

[0053] Although there are N 1×K WSSs and N K×1 WSSs in each direction, there are only two WSSs in the optical path connection: one 1×K WSS for the inlet (signal input) and one K×1 WSS for the outlet (signal output).

[0054] When the number of WSSs in the optical path connection is 2, the polarization dependent loss (PDL) associated with the signal information carried by each of the two vertically polarized beams is considered to be the lowest. This parameter averages 0.4 dB for each WSS.

[0055] It should be noted that splitter 201 is coupled to N 1×K WSSs, which means there are N×K branch ports in the second stage in each direction (degrees). Correspondingly, combiner 204 is coupled to N K×1 WSSs, which means there are N×K branch ports in the third stage in each direction (degrees). Therefore, the value of D can be greater than or equal to the value of K.

[0056] Based on this four-level architecture, the degree expansion of ROADM nodes is not limited by the size of the WSS. Therefore, in embodiments of this invention, an existing WSS size can be used, or the WSS size can be expanded.

[0057] For example, K ≥ 16. For example, K = 16, 32, or 64. With this arrangement, higher degrees can be achieved using fewer splitters, combiners, and WSSs.

[0058] For example, WSS can use liquid crystal on silicon (LCOS) technology.

[0059] For example, D ≥ 16. For example, D = 16, 30, 32, 60, or 120.

[0060] In the ROADM node provided in this embodiment of the invention, a four-level architecture is constituted by a first-level splitter, a second-level first WSS, a third-level second WSS, and a fourth-level combiner. A first fiber of degree (direction) is coupled to N first WSSs in a group of first WSSs via a splitter. These N first WSSs are then coupled to second WSSs in different groups of second WSSs within a group of D second WSSs. N second WSSs in a group of second WSSs are coupled to a second fiber of the same degree via a combiner. Thus, by combining different types of splitters and combiners, and different sizes of WSSs, flexible coupling of a first fiber of degree to second fibers of multiple degrees can be achieved. Since N first WSSs are coupled to a splitter and N second WSSs are coupled to a combiner, this scheme can achieve multiple degrees compared to a scheme that couples only one WSS per degree, and it has the ability to expand to higher degrees. Furthermore, ROADM nodes can simultaneously support flexible and fixed grids without spectral loss; therefore, they can support full-spectrum switching from input to output. Building on this, the controller can manage the second-stage WSS to select the wavelength at its input, ensuring that no two identical wavelengths exist at the input of the third-stage WSS, thus preventing crosstalk at that wavelength. Therefore, it is possible to achieve a crosstalk-free and non-blocking architecture.

[0061] In some embodiments, such as Figures 4 to 8D As shown, a first WSS 202 is fully connected to a second WSS 203 in group D.

[0062] In this way, during the process of transmitting the signal from the first optical fiber 31 to the second optical fiber 32, the wavelength received by the first optical fiber 31 of any degree can be assigned to the second optical fiber 32 of any degree, thereby realizing a mesh connection and enabling the ROADM node to have the ability to be colorless and directionless.

[0063] In some implementations, such as Figures 4 to 8D As shown, the second WSS 203 in group D can be divided into N second clusters 500, and each second cluster 500 includes D / N groups of second WSS 203. The D / N branch ports 2022 of each first WSS 202 in this group are coupled one-to-one to the branch ports 2032 of the D / N second WSS 203 in the j-th second cluster 500 corresponding to each first WSS 202. Any two of the D / N second WSS 203 in the j-th cluster 500 are located in different groups of second WSS 203, where j is a positive integer greater than or equal to 1 and less than or equal to N (1≤j≤N).

[0064] It should be understood that any set of second WSS 203 located in the second cluster 500 is not located in another second cluster 500. Figure 4 For example, any group of second WSS 203 located in the second cluster 501 is not located in the second cluster 502, and any group of second WSS 203 located in the second cluster 502 is not located in the second cluster 501.

[0065] N first WSS 202s in a group of first WSS 202s are each coupled to N second clusters 500. Still using... Figure 4 For example, two first WSS 202s in a group of first WSS 202s are coupled to two second clusters 500 respectively. The upper first WSS 202 in this group of first WSS 202s can be coupled to the second cluster 501, and the lower first WSS 202 in this group of first WSS 202s can be coupled to the second cluster 502; or, the upper first WSS 202 in this group of first WSS 202s can be coupled to the second cluster 502, and the lower first WSS 202 in this group of first WSS 202s can be coupled to the second cluster 501.

[0066] Since the D / N tributary ports 2022 of each first WSS 202 in the group are coupled one-to-one to the tributary ports 2032 of the corresponding D / N second WSS 203 in the second cluster 500, and the D / N second WSS 203 in the second cluster 500 are respectively located in the D / N group of second WSS 203 in the second cluster 500, the group of first WSS 202 can be connected to the second WSS 203 in each direction, thereby achieving full connectivity.

[0067] In some embodiments, such as Figures 4 to 8D As shown, a second WSS 203 is fully connected to the first WSS 202 in group D.

[0068] In this way, during the process of transmitting the signal from the first optical fiber 31 to the second optical fiber 32, the second optical fiber 32 of any degree can receive the wavelengths transmitted by the first optical fiber 31 of all degrees, thereby realizing a mesh connection and enabling the ROADM node to have colorless and directionless capabilities.

[0069] In some implementations, such as Figures 4 to 8D As shown, the first WSS 202 in group D can be divided into N first clusters 400, and each first cluster 400 includes D / N groups of first WSS 202. The D / N branch ports 2032 of each second WSS 203 in this group are coupled one-to-one to the branch ports 2022 of the D / N first WSS 202 in the i-th first cluster 400 corresponding to each second WSS 203. Any two of the D / N first WSS 202 in the i-th cluster 400 are located in different groups of first WSS 202, where i is a positive integer greater than or equal to 1 and less than or equal to N (1≤i≤N).

[0070] It should be understood that any set of first WSS 202 located in the first cluster 400 is not located in another first cluster 400. Figure 4 For example, any group of first WSS 202 located in the first cluster 401 is not located in the first cluster 402, and any group of first WSS 202 located in the first cluster 402 is not located in the first cluster 401.

[0071] N second WSS 203s in a group of second WSS 203s are each coupled to N first clusters 400. Still using... Figure 4 For example, two second WSS 203s in a group of second WSS 203s are coupled to two first clusters 400 respectively. The upper second WSS 203 in this group of second WSS 203s can be coupled to the first cluster 401, and the lower second WSS 203 in this group of second WSS 203s can be coupled to the first cluster 402; or, the upper second WSS 203 in this group of second WSS 203s can be coupled to the first cluster 402, and the lower second WSS 203 in this group of second WSS 203s can be coupled to the first cluster 401.

[0072] Since the D / N tributary ports 2032 of each second WSS 203 in the group are coupled one-to-one to the tributary ports 2022 of the corresponding D / N first WSS 202 in the first cluster 400, and the D / N first WSS 202 in the first cluster 400 are respectively located in the D / N group of first WSS 202 in the first cluster 400, the group of second WSS 203 can be connected to the first WSS 202 in each direction, thereby achieving full connectivity.

[0073] In some examples, D = N×(K–S'), where K represents the number of branch ports 2022 of the first WSS 202 coupled to the second WSS 203, S' represents the number of branch ports 2022 in the first WSS 202 that are different from the branch ports 2022 coupled to these second WSSs 203, and S' is a positive integer less than K (S' < K). The branch ports 2022 in the first WSS 202 that are different from the branch ports 2022 coupled to these second WSSs 203 include the branch ports 2022 for add / drop (i.e., the branch ports 2022 coupled to the third WSS described below) and other branch ports 2022 other than the branch ports 2022 for add / drop and the branch ports 2022 coupled to these second WSSs 203.

[0074] For example, as Figure 4 shown, D = 16, N = 2, K = 16. In this case, S' = 8. Each group of the first WSS 202 includes an upper first WSS 202 and a lower first WSS 202, and each group of the second WSS 203 includes an upper second WSS 203 and a lower second WSS 203. The 16 groups of the first WSS 202 can be divided into two first clusters 400 (the first cluster 401 and the first cluster 402 respectively); the first cluster 401 includes the first group of the first WSS 202 to the eighth group of the first WSS 202, and the first cluster 402 includes the ninth group of the first WSS 202 to the 16th group of the first WSS 202. The 16 groups of the second WSS 203 can be divided into two second clusters 500 (the second cluster 501 and the second cluster 502 respectively); the second cluster 501 includes the first group of the second WSS 203 to the eighth group of the second WSS 203, and the second cluster 502 includes the ninth group of the second WSS 203 to the 16th group of the second WSS 203.

[0075] For each group of first WSS 202 in the first cluster 401, the eight branch ports 2022 of the upper first WSS 202 in the group are coupled one-to-one to the eight branch ports 2032 of the upper second WSS 203 in the second cluster 501, and the eight branch ports 2022 of the lower first WSS 202 in the group are coupled one-to-one to the eight branch ports 2032 of the lower second WSS 203 in the second cluster 502. For example, in the first group of first WSS 202 in the first cluster 401, the eight branch ports 2022 of the upper first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the eight upper second WSS 203 in the second cluster 501, and the eight branch ports 2022 of the lower first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the eight lower second WSS 203 in the second cluster 502. For the eighth group of first WSS 202 in the first cluster 401, the eight branch ports 2022 of the upper first WSS 202 in the eighth group of first WSS 202 are coupled one-to-one to the eighth branch ports 2032 of the eight upper second WSS 203 in the second cluster 501, and the eight branch ports 2022 of the lower first WSS 202 in the eighth group of first WSS 202 are coupled one-to-one to the eighth branch ports 2032 of the eight lower second WSS 203 in the second cluster 502.

[0076] For each group of first WSS 202 in the first cluster 402, the eight branch ports 2022 of the upper first WSS 202 in the group are coupled one-to-one to the eight branch ports 2032 of the upper second WSS 203 in the second cluster 502, and the eight branch ports 2022 of the lower first WSS 202 in the group are coupled one-to-one to the eight branch ports 2032 of the lower second WSS 203 in the second cluster 501. For example, in the ninth group of the first WSS 202 in the first cluster 402, the eight branch ports 2022 of the upper first WSS 202 in the ninth group of the first WSS 202 are coupled one-to-one to the first branch ports 2032 of the eight upper second WSS 203 in the second cluster 502, and the eight branch ports 2022 of the lower first WSS 202 in the ninth group of the first WSS 202 are coupled one-to-one to the first branch ports 2032 of the eight lower second WSS 203 in the second cluster 501. For the 16th group of the first WSS 202 in the first cluster 402, the eight branch ports 2022 of the upper first WSS 202 in the 16th group of the first WSS 202 are coupled one-to-one to the eighth branch ports 2032 of the eight upper second WSS 203 in the second cluster 502, and the eight branch ports 2022 of the lower first WSS 202 in the 16th group of the first WSS 202 are coupled one-to-one to the eighth branch ports 2032 of the eight lower second WSS 203 in the second cluster 501.

[0077] For example, such as Figure 5 As shown, D=30, N=2, K=16. In this case, S'=1. Each group of first WSS 202 includes an upper first WSS 202 and a lower first WSS 202, and each group of second WSS 203 includes an upper second WSS 203 and a lower second WSS 203. The 30 groups of first WSS 202 can be divided into two first clusters 400 (first cluster 401 and first cluster 402, respectively); first cluster 401 includes first WSS 202 to the 15th group of first WSS 202, and first cluster 402 includes first WSS 202 to the 30th group of first WSS 202. The 30 groups of second WSS 203 can be divided into two second clusters 500 (second cluster 501 and second cluster 502, respectively); second cluster 501 includes second WSS 203 to the 15th group of second WSS 203, and second cluster 502 includes second WSS 203 to the 30th group of second WSS 203.

[0078] For each group of first WSS 202 in the first cluster 401, the 15 branch ports 2022 of the upper first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 15 branch ports 2032 of the upper second WSS 203 in the second cluster 501, and the 15 branch ports 2022 of the lower first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 15 branch ports 2032 of the lower second WSS 203 in the second cluster 502. For example, in the first group of first WSS 202 in the first cluster 401, the 15 branch ports 2022 of the upper first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 15 upper second WSS 203 in the second cluster 501, and the 15 branch ports 2022 of the lower first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 15 lower second WSS 203 in the second cluster 502. For the 15th group of the first WSS 202 in the first cluster 401, the 15 branch ports 2022 of the upper first WSS 202 in the 15th group of the first WSS 202 are coupled one-to-one to the 15th branch ports 2032 of the 15 upper second WSS 203 in the second cluster 501, and the 15 branch ports 2022 of the lower first WSS 202 in the 15th group of the first WSS 202 are coupled one-to-one to the 15th branch ports 2032 of the 15 lower second WSS 203 in the second cluster 502.

[0079] For each group of first WSS 202 in the first cluster 402, the 15 branch ports 2022 of the upper first WSS 202 in the group are coupled one-to-one to the 15 branch ports 2032 of the upper second WSS 203 in the second cluster 502, and the 15 branch ports 2022 of the lower first WSS 202 in the group are coupled one-to-one to the 15 branch ports 2032 of the lower second WSS 203 in the second cluster 501. For example, in the 16th group of the first WSS 202 in the first cluster 402, the 15 branch ports 2022 of the upper first WSS 202 in the 16th group of the first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 15 upper second WSS 203 in the second cluster 502, and the 15 branch ports 2022 of the lower first WSS 202 in the 16th group of the first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 15 lower second WSS 203 in the second cluster 501. For the 30th group of the first WSS 202 in the first cluster 402, the 15 branch ports 2022 of the upper first WSS 202 in the 30th group of the first WSS 202 are coupled one-to-one to the 15th branch ports 2032 of the 15 upper second WSS 203 in the second cluster 502, and the 15 branch ports 2022 of the lower first WSS 202 in the 30th group of the first WSS 202 are coupled one-to-one to the 15th branch ports 2032 of the 15 lower second WSS 203 in the second cluster 501.

[0080] For example, such as Figure 6 As shown, D=60, N=2, K=32. In this case, S'=2. Each group of first WSS 202 includes an upper first WSS 202 and a lower first WSS 202, and each group of second WSS 203 includes an upper second WSS 203 and a lower second WSS 203. The 60 groups of first WSS 202 can be divided into two first clusters 400 (first cluster 401 and first cluster 402, respectively); first cluster 401 includes first WSS 202 to the 30th group of first WSS 202, and first cluster 402 includes first WSS 202 31 to the 60th group of first WSS 202. The 60 groups of second WSS 203 can be divided into two second clusters 500 (second cluster 501 and second cluster 502, respectively); second cluster 501 includes second WSS 203 to the 30th group of second WSS 203, and second cluster 502 includes second WSS 203 31 to the 60th group of second WSS 203.

[0081] For each group of first WSS 202 in the first cluster 401, the 30 branch ports 2022 of the upper first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 30 branch ports 2032 of the upper second WSS 203 in the second cluster 501, and the 30 branch ports 2022 of the lower first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 30 branch ports 2032 of the lower second WSS 203 in the second cluster 502. For example, in the first group of first WSS 202 in the first cluster 401, the 30 branch ports 2022 of the upper first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 upper second WSS 203 in the second cluster 501, and the 30 branch ports 2022 of the lower first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 lower second WSS 203 in the second cluster 502. For the 30th group of the first WSS 202 in the first cluster 401, the 30 branch ports 2022 of the upper first WSS 202 in the 30th group of the first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 upper second WSS 203 in the second cluster 501, and the 30 branch ports 2022 of the lower first WSS 202 in the 30th group of the first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 lower second WSS 203 in the second cluster 502.

[0082] For each group of first WSS 202 in the first cluster 402, the 30 branch ports 2022 of the upper first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 30 branch ports 2032 of the upper second WSS 203 in the second cluster 502, and the 30 branch ports 2022 of the lower first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 30 branch ports 2032 of the lower second WSS 203 in the second cluster 501. For example, in the first WSS 202 of the 31st group in the first cluster 402, the 30 branch ports 2022 of the upper first WSS 202 in the 31st group are coupled one-to-one to the first branch ports 2032 of the 30 upper second WSS 203 in the second cluster 502, and the 30 branch ports 2022 of the lower first WSS 202 in the 31st group are coupled one-to-one to the first branch ports 2032 of the 30 lower second WSS 203 in the second cluster 501. For the 60th group of the first WSS 202 in the first cluster 402, the 30 branch ports 2022 of the upper first WSS 202 in the 60th group of the first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 upper second WSS 203 in the second cluster 502, and the 30 branch ports 2022 of the lower first WSS 202 in the 60th group of the first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 lower second WSS 203 in the second cluster 501.

[0083] For example, such as Figure 7 As shown, D=120, N=2, K=64. In this case, S'=4. Each group of first WSS 202 includes an upper first WSS 202 and a lower first WSS 202, and each group of second WSS 203 includes an upper second WSS 203 and a lower second WSS 203. The 120 groups of first WSS 202 can be divided into two first clusters 400 (first cluster 401 and first cluster 402, respectively); first cluster 401 includes first WSS 202 to the 60th group of first WSS 202, and first cluster 402 includes first WSS 202 61 to the 120th group of first WSS 202. The 120 groups of second WSS 203 can be divided into two second clusters 500 (second cluster 501 and second cluster 502, respectively); second cluster 501 includes second WSS 203 to the 60th group of second WSS 203, and second cluster 502 includes second WSS 203 61 to the 120th group of second WSS 203.

[0084] For each group of first WSS 202 in the first cluster 401, the 60 branch ports 2022 of the upper first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 60 branch ports 2032 of the upper second WSS 203 in the second cluster 501, and the 60 branch ports 2022 of the lower first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 60 branch ports 2032 of the lower second WSS 203 in the second cluster 502. For example, in the first group of first WSS 202 in the first cluster 401, the 60 branch ports 2022 of the upper first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 60 upper second WSS 203 in the second cluster 501, and the 60 branch ports 2022 of the lower first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 60 lower second WSS 203 in the second cluster 502. For the 60th group of the first WSS 202 in the first cluster 401, the 60 branch ports 2022 of the upper first WSS 202 in the 60th group of the first WSS 202 are coupled one-to-one to the 60th branch ports 2032 of the 60 upper second WSS 203 in the second cluster 501, and the 60 branch ports 2022 of the lower first WSS 202 in the 60th group of the first WSS 202 are coupled one-to-one to the 60th branch ports 2032 of the 60 lower second WSS 203 in the second cluster 502.

[0085] For each group of first WSS 202 in the first cluster 402, the 60 branch ports 2022 of the upper first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 60 branch ports 2032 of the upper second WSS 203 in the second cluster 502, and the 60 branch ports 2022 of the lower first WSS 202 in the group of first WSS 202 are coupled one-to-one to the 60 branch ports 2032 of the lower second WSS 203 in the second cluster 501. For example, in the first WSS 202 of the 61st group in the first cluster 402, the 60 branch ports 2022 of the upper first WSS 202 in the 61st group are coupled one-to-one to the first branch ports 2032 of the 60 upper second WSS 203 in the second cluster 502, and the 60 branch ports 2022 of the lower first WSS 202 in the 61st group are coupled one-to-one to the first branch ports 2032 of the 60 lower second WSS 203 in the second cluster 501. For the 120th group of the first WSS 202 in the first cluster 402, the 60 branch ports 2022 of the upper first WSS 202 in the 120th group of the first WSS 202 are coupled one-to-one to the 60th branch ports 2032 of the 60 upper second WSS 203 in the second cluster 502, and the 60 branch ports 2022 of the lower first WSS 202 in the 120th group of the first WSS 202 are coupled one-to-one to the 60th branch ports 2032 of the 60 lower second WSS 203 in the second cluster 501.

[0086] For example, such as Figures 8A to 8D As shown, D=120, N=4, K=32. In this case, S'=2. Each group of first WSS202 includes first first WSS 202, second first WSS 202, third first WSS 202, and fourth first WSS 202 (from top to bottom). The 120 groups of first WSS 202 can be divided into four first clusters 400 (namely first cluster 401, first cluster 402, first cluster 403, and first cluster 404); first cluster 401 includes first group of first WSS 202 to 30th group of first WSS202, first cluster 402 includes first group of first WSS 202 to 60th group of first WSS 202, first cluster 403 includes first group of first WSS 202 to 90th group of first WSS 202, and first cluster 404 includes first group of first WSS 202 to 120th group of first WSS 202.

[0087] refer to Figure 8AThe first cluster 401 includes a first sub-cluster 4011, a second sub-cluster 4012, a third sub-cluster 4013, and a fourth sub-cluster 4014. The first sub-cluster 4011 includes 30 first WSSs 202, each first WSS being the first of a set of first WSSs 202 in the first cluster 401; the second sub-cluster 4012 includes 30 first WSSs 202, each first WSS being the second of a set of first WSSs 202 in the first cluster 401; the third sub-cluster 4013 includes 30 first WSSs 202, each first WSS being the third of a set of first WSSs 202 in the first cluster 401; and the fourth sub-cluster 4014 includes 30 first WSSs 202, each first WSS being the fourth of a set of first WSSs 202 in the first cluster 401.

[0088] refer to Figure 8B The first cluster 402 includes a fifth sub-cluster 4021, a sixth sub-cluster 4022, a seventh sub-cluster 4023, and an eighth sub-cluster 4024. The fifth sub-cluster 4021 includes 30 first WSSs 202, each first WSS being the first of a set of first WSSs 202 in the first cluster 402; the sixth sub-cluster 4022 includes 30 first WSSs 202, each first WSS being the second of a set of first WSSs 202 in the first cluster 402; the seventh sub-cluster 4023 includes 30 first WSSs 202, each first WSS being the third of a set of first WSSs 202 in the first cluster 402; and the eighth sub-cluster 4024 includes 30 first WSSs 202, each first WSS being the fourth of a set of first WSSs 202 in the first cluster 402.

[0089] refer to Figure 8CThe first cluster 403 includes a ninth sub-cluster 4031, a tenth sub-cluster 4032, an eleventh sub-cluster 4033, and a twelfth sub-cluster 4034. The ninth sub-cluster 4031 includes 30 first WSSs 202, each first WSS being the first first WSS 202 in a group of first WSSs 202 in the first cluster 403; the tenth sub-cluster 4032 includes 30 first WSSs 202, each first WSS being the second first WSS 202 in a group of first WSSs 202 in the first cluster 403; the eleventh sub-cluster 4033 includes 30 first WSSs 202, each first WSS being the third first WSS 202 in a group of first WSSs 202 in the first cluster 403; and the twelfth sub-cluster 4034 includes 30 first WSSs 202, each first WSS being the fourth first WSS 202 in a group of first WSSs 202 in the first cluster 403.

[0090] refer to Figure 8D The first cluster 404 includes the 13th sub-cluster 4041, the 14th sub-cluster 4042, the 15th sub-cluster 4043, and the 16th sub-cluster 4044. The 13th sub-cluster 4041 includes 30 first WSSs 202, each first WSS being the first first WSS 202 in a group of first WSSs 202 in the first cluster 404; the 14th sub-cluster 4042 includes 30 first WSSs 202, each first WSS being the second first WSS 202 in a group of first WSSs 202 in the first cluster 404; the 15th sub-cluster 4043 includes 30 first WSSs 202, each first WSS being the third first WSS 202 in a group of first WSSs 202 in the first cluster 404; the 16th sub-cluster 4044 includes 30 first WSSs 202, each first WSS being the fourth first WSS 202 in a group of first WSSs 202 in the first cluster 404.

[0091] Each group of second WSS 203 includes a first second WSS 203, a second second WSS 203, a third second WSS 203, and a fourth second WSS 203 (from top to bottom). The 120 groups of second WSS 203 can be divided into four second clusters 500 (namely, second cluster 501, second cluster 502, second cluster 503, and second cluster 504); second cluster 501 includes the first group of second WSS 203 to the 30th group of second WSS 203, second cluster 502 includes the 31st group of second WSS 203 to the 60th group of second WSS 203, second cluster 503 includes the 61st group of second WSS 203 to the 90th group of second WSS 203, and second cluster 504 includes the 91st group of second WSS 203 to the 120th group of second WSS 203.

[0092] refer to Figure 8A The second cluster 501 includes the 17th sub-cluster 5011, the 18th sub-cluster 5012, the 19th sub-cluster 5013, and the 20th sub-cluster 5014. Sub-cluster 17 5011 includes 30 second WSSs 203, each second WSS being the first second WSS 203 in a group of second WSSs 203 in the second cluster 501; Sub-cluster 18 5012 includes 30 second WSSs 203, each second WSS being the second second WSS 203 in a group of second WSSs 203 in the second cluster 501; Sub-cluster 19 5013 includes 30 second WSSs 203, each second WSS being the third second WSS 203 in a group of second WSSs 203 in the second cluster 501; Sub-cluster 20 5014 includes 30 second WSSs 203, each second WSS being the fourth second WSS 203 in a group of second WSSs 203 in the second cluster 501.

[0093] refer to Figure 8B The second cluster 502 includes the 21st sub-cluster 5021, the 22nd sub-cluster 5022, the 23rd sub-cluster 5023, and the 24th sub-cluster 5024. Sub-cluster 21 5021 includes 30 second WSSs 203, each second WSS being the first second WSS 203 in a group of second WSSs 203 in the second cluster 502; Sub-cluster 22 5022 includes 30 second WSSs 203, each second WSS being the second second WSS 203 in a group of second WSSs 203 in the second cluster 502; Sub-cluster 23 5023 includes 30 second WSSs 203, each second WSS being the third second WSS 203 in a group of second WSSs 203 in the second cluster 502; Sub-cluster 24 5024 includes 30 second WSSs 203, each second WSS being the fourth second WSS 203 in a group of second WSSs 203 in the second cluster 502.

[0094] refer to Figure 8CThe second cluster 503 includes the 25th sub-cluster 5031, the 26th sub-cluster 5032, the 27th sub-cluster 5033, and the 28th sub-cluster 5034. Sub-cluster 25 5031 includes 30 second WSSs 203, each second WSS being the first second WSS 203 in a group of second WSSs 203 within the second cluster 503; Sub-cluster 26 5032 includes 30 second WSSs 203, each second WSS being the second second WSS 203 in a group of second WSSs 203 within the second cluster 503; Sub-cluster 27 5033 includes 30 second WSSs 203, each second WSS being the third second WSS 203 in a group of second WSSs 203 within the second cluster 503; Sub-cluster 28 5034 includes 30 second WSSs 203, each second WSS being the fourth second WSS 203 in a group of second WSSs 203 within the second cluster 503.

[0095] refer to Figure 8D The second cluster 504 includes the 29th sub-cluster 5041, the 30th sub-cluster 5042, the 31st sub-cluster 5043, and the 32nd sub-cluster 5044. Sub-cluster 29 5041 includes 30 second WSSs 203, each second WSS being the first second WSS 203 in a set of second WSSs 203 in the second cluster 504; Sub-cluster 30 5042 includes 30 second WSSs 203, each second WSS being the second second WSS 203 in a set of second WSSs 203 in the second cluster 504; Sub-cluster 31 5043 includes 30 second WSSs 203, each second WSS being the third second WSS 203 in a set of second WSSs 203 in the second cluster 504; Sub-cluster 32 5044 includes 30 second WSSs 203, each second WSS being the fourth second WSS 203 in a set of second WSSs 203 in the second cluster 504.

[0096] like Figure 8AAs shown, the 30 branch ports of each first WSS 202 in the first sub-cluster 4011 are coupled one-to-one to the 30 second WSS 203 in the 17th sub-cluster 5011; the 30 branch ports of each first WSS 202 in the second sub-cluster 4012 are coupled one-to-one to the 30 second WSS 203 in the 22nd sub-cluster 5022; the 30 branch ports of each first WSS 202 in the third sub-cluster 4013 are coupled one-to-one to the 30 second WSS 203 in the 27th sub-cluster 5033; and the 30 branch ports of each first WSS 202 in the fourth sub-cluster 4014 are coupled one-to-one to the 30 second WSS 203 in the 32nd sub-cluster 5044. For example, for the first sub-cluster 4011, the 30 branch ports 2022 of the first WSS 202 in the first group of the first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 17th sub-cluster 5011, and the 30 branch ports 2022 of the first WSS 202 in the 30th group of the first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 17th sub-cluster 5011. For the second sub-cluster 4012, the 30 branch ports 2022 of the second WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 22nd sub-cluster 5022, and the 30 branch ports 2022 of the second WSS 202 in the 30th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 22nd sub-cluster 5022. For the third sub-cluster 4013, the 30 branch ports 2022 of the third first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 27th sub-cluster 5033, and the 30 branch ports 2022 of the third first WSS 202 in the 30th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 27th sub-cluster 5033. For the fourth sub-cluster 4014, the 30 branch ports 2022 of the fourth first WSS 202 in the first group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 32nd sub-cluster 5044, and the 30 branch ports 2022 of the fourth first WSS 202 in the 30th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 32nd sub-cluster 5044.

[0097] like Figure 8BAs shown, the 30 branch ports of each first WSS 202 in the fifth sub-cluster 4021 are coupled one-to-one to the 30 second WSS 203 in the 21st sub-cluster 5021; the 30 branch ports of each first WSS 202 in the sixth sub-cluster 4022 are coupled one-to-one to the 30 second WSS 203 in the 26th sub-cluster 5032; the 30 branch ports of each first WSS 202 in the seventh sub-cluster 4023 are coupled one-to-one to the 30 second WSS 203 in the 31st sub-cluster 5043; and the 30 branch ports of each first WSS 202 in the eighth sub-cluster 4024 are coupled one-to-one to the 30 second WSS 203 in the 20th sub-cluster 5014. For example, for the fifth sub-cluster 4021, the 30 branch ports 2022 of the first WSS 202 in the 31st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 21st sub-cluster 5021, and the 30 branch ports 2022 of the first WSS 202 in the 60th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 21st sub-cluster 5021. For the sixth sub-cluster 4022, the 30 branch ports 2022 of the second first WSS 202 in the 31st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 26th sub-cluster 5032, and the 30 branch ports 2022 of the second first WSS 202 in the 60th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 26th sub-cluster 5032. For the seventh sub-cluster 4023, the 30 branch ports 2022 of the third first WSS 202 in the 31st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 31st sub-cluster 5043, and the 30 branch ports 2022 of the third first WSS 202 in the 60th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 31st sub-cluster 5043. For the eighth sub-cluster 4024, the 30 branch ports 2022 of the fourth first WSS 202 in the 31st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 20th sub-cluster 5014, and the 30 branch ports 2022 of the fourth first WSS 202 in the 60th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 20th sub-cluster 5014.

[0098] like Figure 8C As shown, the 30 branch ports of each first WSS 202 in the ninth sub-cluster 4031 are coupled one-to-one to the 30 second WSS 203 in the 25th sub-cluster 5031, the 30 branch ports of each first WSS 202 in the tenth sub-cluster 4032 are coupled one-to-one to the 30 second WSS 203 in the 30th sub-cluster 5042, the 30 branch ports of each first WSS 202 in the 11th sub-cluster 4033 are coupled one-to-one to the 30 second WSS 203 in the 19th sub-cluster 5013, and the 30 branch ports of each first WSS 202 in the 12th sub-cluster 4034 are coupled one-to-one to the 30 second WSS 203 in the 24th sub-cluster 5024. For example, for the ninth sub-cluster 4031, the 30 branch ports 2022 of the first WSS 202 in the 61st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 25th sub-cluster 5031, and the 30 branch ports 2022 of the first WSS 202 in the 90th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 25th sub-cluster 5031. For the tenth sub-cluster 4032, the 30 branch ports 2022 of the second first WSS 202 in the 61st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 30th sub-cluster 5042, and the 30 branch ports 2022 of the second first WSS 202 in the 90th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 30th sub-cluster 5042. For the 11th sub-cluster 4033, the 30 branch ports 2022 of the third first WSS 202 in the 61st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 19th sub-cluster 5013, and the 30 branch ports 2022 of the third first WSS 202 in the 90th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 19th sub-cluster 5013. For the 12th sub-cluster 4034, the 30 branch ports 2022 of the fourth first WSS 202 in the 61st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 24th sub-cluster 5024, and the 30 branch ports 2022 of the fourth first WSS 202 in the 90th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 24th sub-cluster 5024.

[0099] like Figure 8D As shown, the 30 tributary ports of each first WSS 202 in the 13th sub-cluster 4041 are coupled one-to-one to the 30 second WSS 203 in the 29th sub-cluster 5041, the 30 tributary ports of each first WSS 202 in the 14th sub-cluster 4042 are coupled one-to-one to the 30 second WSS 203 in the 18th sub-cluster 5012, the 30 tributary ports of each first WSS 202 in the 15th sub-cluster 4043 are coupled one-to-one to the 30 second WSS 203 in the 23rd sub-cluster 5023, and the 30 tributary ports of each first WSS 202 in the 16th sub-cluster 4044 are coupled one-to-one to the 30 second WSS 203 in the 28th sub-cluster 5034. For example, for the 13th sub-cluster 4041, the 30 branch ports 2022 of the first WSS 202 in the 91st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 29th sub-cluster 5041, and the 30 branch ports 2022 of the first WSS 202 in the 120th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 29th sub-cluster 5041. For the 14th sub-cluster 4042, the 30 branch ports 2022 of the second WSS 202 in the 91st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 18th sub-cluster 5012, and the 30 branch ports 2022 of the second WSS 202 in the 120th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 18th sub-cluster 5012. For the 15th sub-cluster 4043, the 30 branch ports 2022 of the third first WSS 202 in the 91st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 23rd sub-cluster 5023, and the 30 branch ports 2022 of the third first WSS 202 in the 120th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 23rd sub-cluster 5023. For the 16th sub-cluster 4044, the 30 branch ports 2022 of the fourth first WSS 202 in the 91st group of first WSS 202 are coupled one-to-one to the first branch ports 2032 of the 30 second WSS 203 in the 28th sub-cluster 5034, and the 30 branch ports 2022 of the fourth first WSS 202 in the 120th group of first WSS 202 are coupled one-to-one to the 30th branch ports 2032 of the 30 second WSS 203 in the 28th sub-cluster 5034.

[0100] In the example above, the optical configuration of the node can be achieved by setting D, N, and K to appropriate values.

[0101] In some embodiments, splitter 201 is a WSS having one common port and N branch ports. In this way, a smaller WSS can be used as splitter 201.

[0102] In some embodiments, combiner 204 is a WSS having one common port and N branch ports. Thus, a smaller WSS can be used as combiner 201.

[0103] In some embodiments, such as Figure 9 and Figure 10 As shown, the ROADM node 20 includes multiple line card chassis 205, and each line card chassis 205 includes multiple line cards 2051. The line card 2051 includes at least one first WSS 202 from group D first WSS 202 and / or at least one second WSS 203 from group D second WSS 203.

[0104] Each line card 2051 can occupy at least one slot in the line card frame 205.

[0105] In some implementations, such as Figure 9 As shown, line card 2051 may include two first WSSs 202, two second WSSs 203, a splitter 201, and a combiner 204. For example, each line card 2051 corresponds to one degree (direction), that is, each line card 2051 includes a splitter 201, two first WSSs 202, two second WSSs 203, and a combiner 204 in one direction.

[0106] Taking the first WSS 202 and the second WSS 203 both having 32 tributary ports, and the splitter 201 and the combiner 204 each having two tributary ports as an example, Figure 9 As shown, the line card chassis 205 can be a 32-slot chassis, with each line card 2051 occupying two slots. Thus, four line card chassis 205 can be used to accommodate all splitters 201, the first WSS 202, the second WSS 203, and the combiner 204 in 60 directions. Each line card 2051 can communicate with other line cards 2051 located in the same line card chassis 205 via a backplane, or with line cards 2051 located in other line card chassis via optical fiber (e.g., ribbon cable).

[0107] In some implementations, such as Figure 10As shown, line card 2051 may include a first WSS 202, a second WSS 203, and a splitter 201. For example, a first WSS 202, a second WSS 203, and a splitter 201 in each direction are located in a line card 2051.

[0108] In some implementations, such as Figure 10 As shown, line card 2051 may include a first WSS 202, a second WSS 203, and a combiner 204. For example, a first WSS 202, a second WSS 203, and a combiner 204 in each direction are located in a line card 2051.

[0109] Taking the example where both the first WSS 202 and the second WSS 203 have 32 tributary ports, and both the splitter 201 and the combiner 204 have two tributary ports, as follows: Figure 10 As shown, the line card frame 205 can be a large frame (e.g., a double-depth frame); the upper first WSS 202 of each group of first WSS 202, the upper second WSS 203 of each group of second WSS 203, and the splitter 201 can be placed in one line card frame 205, and the lower first WSS 202 of each group of first WSS 202, the lower second WSS 203 of each group of second WSS 203, and the combiner 204 can be placed in another line card frame 205. Thus, two frames can be used to accommodate all the splitters 201, first WSS 202, second WSS 203, and combiners 204 in 60 directions.

[0110] Within the same double-depth chassis, some line cards 2051 may be located on one side of the middle plate 2052, while the remaining line cards 2051 may be located on the other side of the middle plate 2052. These line cards 2051 can be coupled via the middle plate 2052. A first WSS 202 and a splitter 201, in the same direction but in different line card chassis 205, can be coupled via connectors on the panel. Similarly, a second WSS 203 and a combiner 204, in the same direction but in different line card chassis 205, can be coupled via connectors on the panel. The panel can be located within one of the chassis.

[0111] For example, a double-depth chassis can have a depth of 600 mm from one side of the middle plate 2052 where the line card 2051 is located to the opposite side.

[0112] In some implementations, line card 2051 includes two first WSSs 202 and a splitter 201. For example, two first WSSs 202 and a splitter 201 in each direction are located in one line card 2051.

[0113] In some implementations, line card 2051 includes two second WSSs 203 and a combiner 204. For example, two second WSSs 203 and a combiner 204 in each direction are located in one line card 2051.

[0114] In these implementations, the line card frame 205 can be as follows: Figure 9 The standard chassis shown, or it could be as follows: Figure 10 The large chassis shown. Please refer to the description above for more information.

[0115] In embodiments of the invention, conventional chassis can be used to house the components in the ROADM node. Therefore, customers may be able to retain their investment in the purchased equipment and maintain forward and backward compatibility for at least one generation, and may also be able to maintain performance as they expand their network. Furthermore, by employing a standard-sized WSS, the degree of the node can be expanded at low cost. Additionally, this allows for flexible design of the line card 2051 within the line card chassis 205.

[0116] In some examples, ROADM node 20 may also include interpolation components for inserting or splitting wavelengths. Interpolation components include, but are not limited to, interpolation components that can be implemented in a colorless, directionless and contentionless (CDC) manner, or interpolation components that can be implemented in a colorless / directionless (CD) manner.

[0117] It should be noted that the following description refers to the output connector (e.g., ...). Figure 11 and Figure 12 The insertion component 206 in the middle) and the insertion component for insertion (e.g., Figure 11 and Figure 12 The two components (207 in the diagram) have the same structure but different signal directions. In this case, the component used for branching out can be called the branching component, and the component used for inserting can be called the inserting component. For the branching component, the signal arrives at the common port of the third WSS of the branching component (described below). For the inserting component, the signal leaves the common port of the third WSS.

[0118] In some embodiments, such as Figure 11 and Figure 12As shown, the ROADM node 20 further includes at least one add-drop component 206 coupled to S branch ports 2022 of the first WSS 202. S is less than K (S < K), and S is a positive integer. In the first WSS 202, the S branch ports 2022 coupled to at least one add-drop component 206 are different from the branch ports 2022 coupled to the branch ports 2032 of the second WSS 203.

[0119] When D / N branch ports 2022 of the first WSS 202 are coupled to the branch ports 2032 of the second WSS 203, S ≤ K – D / N. When the first optical fiber 31 is an input optical fiber and the second optical fiber is an output optical fiber, at least one add-drop component 206 coupled to the S branch ports 2022 of the first WSS 202 is used to drop wavelengths.

[0120] In some embodiments, as Figure 11 and Figure 12 shown, the ROADM node 20 further includes at least one add-drop component 207 coupled to T branch ports 2032 of the second WSS 203. T is less than K (T < K), and T is a positive integer. In the second WSS 203, the T branch ports 2032 coupled to at least one add-drop component 207 are different from the branch ports 2032 coupled to the branch ports 2022 of the first WSS 202.

[0121] When D / N branch ports 2032 of the second WSS 203 are coupled to the branch ports 2022 of the first WSS 202, T ≤ K – D / N. When the first optical fiber 31 is an input optical fiber and the second optical fiber is an output optical fiber, at least one add-drop component 207 coupled to the T branch ports 2032 of the second WSS 203 is used to add wavelengths.

[0122] By providing the add-drop component 206 and the add-drop component 207, the ROADM node 20 may be able to flexibly add and drop wavelengths.

[0123] The structure of only the add-drop component 206 will be described below. For the structure of the add-drop component 207, reference may be made to the description of the add-drop component 206.

[0124] In some implementations, as Figure 11 and Figure 12As shown, the add / drop assembly 206 may include D' third WSSs 208 and K add / drop cards 209. Each third WSS 208 has a common port 2081 and K tributary ports 2082. In the add / drop assembly 206, the common port 2081 of the D' third WSSs 208 is coupled one-to-one with the D' tributary ports 2022 of multiple first WSSs 202, and the K tributary ports 2082 of the third WSSs 208 are coupled to the K add / drop cards 209 respectively. D' is a positive integer. With this arrangement, the first WSSs 202 coupled to the common port 2081 of the D' third WSSs 208 can simultaneously split wavelengths.

[0125] For example, the third WSS 208 has one common port 2081 and 32 tributary ports 2082.

[0126] When S is greater than 1 (S≥1), the S branch ports 2022 of the first WSS 202 can be coupled to the same plug-in component 206; or, the S branch ports 2022 of the first WSS 202 can be coupled to the S plug-in components 206 respectively; or, at least one branch port of the S branch ports 2022 of the first WSS 202 is coupled to a plug-in component 206, and the remaining branch ports of the S branch ports 2022 of the first WSS 202 are coupled to at least one plug-in component 206.

[0127] In some examples, D' equals D (D'=D), and the common port 2081 of the D third WSSs 208 in the add-drop assembly 206 is coupled one-to-one to the D tributary ports 2022 of the D first WSSs 202. That is, the common port 2081 of each third WSS 208 is coupled to one tributary port 2022 of the first WSS 202. With this arrangement, the node configuration can be further optimized because all wavelengths can be branched from the D first fibers 31.

[0128] For example, at least one interpolation component 206 comprises M interpolation components 206; 2 ≤ M ≤ N × S, where M is a positive integer. D first WSSs 202 coupled to D third WSSs 208 in the interpolation component 206 are respectively located in D groups of first WSSs 202, with each first WSS 202 in each group of first WSSs 202 coupled to a different interpolation component 206. In this way, each interpolation component 206 can separate wavelengths at all degrees.

[0129] For example, such as Figure 6 and Figure 11As shown, a ROADM node may include two plug-in components 206, wherein one plug-in component 206 is coupled to all upper first WSS 202s in the first WSS 202 of group D, and the other plug-in component 206 is coupled to all lower first WSS 202s in the first WSS 202 of group D. The common port 2081 of the D third WSS 208s in the plug-in component 206 coupled to all upper first WSS 202s in the first WSS 202 of group D can be coupled one-to-one to the 31st branch port 2022 of all upper first WSS 202s, and the common port 2081 of the D third WSS 208s in the plug-in component 206 coupled to all lower first WSS 202s in group D can be coupled one-to-one to the 31st branch port 2022 of all lower first WSS 202s.

[0130] For example, such as Figure 6 and Figure 11 As shown, a ROADM node may include four plug-in components 206, wherein two plug-in components 206 are coupled to all upper first WSS 202s in the first WSS 202 of group D, and the other two plug-in components 206 are coupled to all lower first WSS 202s in the first WSS 202 of group D. The common port 2081 of D third WSS 208s in one plug-in component 206 coupled to all upper first WSS 202s in group D can be coupled one-to-one to the 31st branch port 2022 of all upper first WSS 202s. The common port 2081 of D third WSS 208s in another plug-in component 206 coupled to all upper first WSS 202s in group D can be coupled one-to-one to the 32nd branch port 2022 of all upper first WSS 202s. The common port 2081 of the D third WSSs 208 in a plug-in assembly 206 coupled to all the lower first WSSs 202 in the first WSS 202 of group D can be coupled one-to-one to the 31st branch port 2022 of all the lower first WSSs 202. The common port 2081 of the D third WSSs 208 in another plug-in assembly 206 coupled to all the lower first WSSs 202 in group D can be coupled one-to-one to the 32nd branch port 2022 of all the lower first WSSs 202.

[0131] It should be noted that for at least one plug-in component 207 coupled to T branch ports 2032 of the second WSS 203, the at least one plug-in component 207 includes M' plug-in components 207; M' is a positive integer greater than or equal to 2 and less than or equal to N×T (2≤M'≤N×T).

[0132] In some embodiments, as Figure 11 shown, the add-drop card 209 includes an add-drop module 210 having Q input ports and P output ports, and a plurality of fourth WSSs 211 each having a common port and U branch ports. The common port of each fourth WSS 211 is coupled to one of the Q input ports of the add-drop module 210, and the U branch ports of the fourth WSS 211 are respectively coupled to U of the D' third WSSs in the add-drop component. U is less than D' (U < D'), and U, P, and Q are all positive integers. The P output ports of the add-drop module 210 are used for dropping or inserting wavelengths.

[0133] It should be noted that the Q input ports of the add-drop module 210 can each be coupled to the fourth WSS 211; alternatively, some of the input ports of the add-drop module 210 can each be coupled to the fourth WSS 211, and in this case, the remaining input ports of the add-drop module 210 can be idle.

[0134] Since the common port of each fourth WSS 211 is coupled to one input port of the add-drop module 210 and each fourth WSS 211 has U branch ports, this solution is equivalent to expanding one input port of the add-drop module 210 to U input ports. Therefore, the add-drop card 209 has at most Q × U input ports.

[0135] By combining the add-drop module 210 with a plurality of fourth WSSs 211 to obtain the add-drop card 209, the add-drop component can be made colorless, directionless, and contentionless (CDC).

[0136] For example, P ≥ 24. For example, P = 24, 64, or 128.

[0137] For example, D' is equal to D. The connection between the D third WSSs 208 in the add-drop component and the first WSS 202 can be seen in the above description.

[0138] For example, D' = 60, K = 32, U = 4, Q = 16. In the add-drop card 209, the first input port to the 15th input port of the add-drop module 210 are each coupled to the fourth WSS 211 (that is, the add-drop card 209 includes 15 fourth WSSs 211). As Figure 11As shown, the first tributary ports 2082 of the 60 third WSSs 208 are coupled one-to-one with the tributary ports of the 15 fourth WSSs 211 in the first expansion card 209 (in a left-to-right direction); the second tributary ports 2082 of the 60 third WSSs 208 are coupled one-to-one with the tributary ports of the 15 fourth WSSs 211 in the second expansion card 209; and so on...; the 32nd tributary ports 2082 of the 60 third WSSs 208 are coupled one-to-one with the tributary ports of the 15 fourth WSSs 211 in the 32nd expansion card 209.

[0139] In some embodiments, the interposer assembly may be a colorless and non-directional interposer assembly. Based on this, such as... Figure 12 As shown, the add / drop card 209 includes an add / drop module 212 having Q' input ports and P output ports. At least a portion of the Q' input ports of the add / drop module 212 are coupled one-to-one with D' third WSSs 208 in the add / drop assembly. Q' is greater than or equal to D' (Q'≥D'), and P and Q' are both positive integers. The P output ports of the add / drop module 212 are used to add or drop wavelengths.

[0140] For example, D' equals D. The connection between the D third WSS 208 and the first WSS 202 in the interpolation assembly can be found in the description above.

[0141] For example, D'=60, K=32, Q'=60. Figure 12 As shown, the first branch ports 2082 of the 60 third WSS 208 are coupled one-to-one with the 60 input ports of the add / drop module 212 in the first add / drop card 209 (in a left-to-right direction); the second branch ports 2082 of the 60 third WSS 208 are coupled one-to-one with the 60 input ports of the add / drop module 212 in the second add / drop card 209; and so on...; the 32nd branch ports 2082 of the 60 third WSS 208 are coupled one-to-one with the 60 input ports of the add / drop module 212 in the 32nd add / drop card 209.

[0142] In some embodiments, such as Figure 13 and Figure 14 As shown, the ROADM node 20 includes at least one WSS chassis 213 and at least one plug-in card chassis 214 corresponding to each plug-in assembly. D' third WSSs 208 in the plug-in assembly are installed in at least one WSS chassis 213, and K plug-in cards 209 in the plug-in assembly are installed in at least one plug-in card chassis 214.

[0143] The third WSS 208 in WSS chassis 213 and the plug-in card 209 in plug-in card chassis 214 can be interconnected via optical fiber.

[0144] By using different chassis to accommodate the third WSS 208 and the plug-in card 209 in the plug-in assembly, the connection between the third WSS 208 and the plug-in card 209 can be facilitated.

[0145] For example, such as Figure 13 As shown, the plug-in assembly includes 60 third WSSs 208 and 32 plug-in cards 209. The third WSSs 208 have one common port 2081 and 32 tributary ports 2082. The plug-in cards 209 include plug-in modules 210 and 15 fourth WSSs 211. Both the WSS chassis 213 and the plug-in card chassis 214 are 32-slot chassis. In the WSS chassis 213, each card occupies two slots, and each card includes a third WSS 208 for plugging out and a third WSS 208 for plugging in. The 32 plug-in cards 209 are mounted in two 32-slot chassis, with each plug-in card 209 occupying two slots. This allows the components in the plug-in assembly to be housed in conventional chassis, enabling customers to retain their investment in the purchased equipment.

[0146] For example, such as Figure 14 As shown, the add-in assembly includes 60 third WSSs 208 and 32 add-in cards 209. The third WSSs 208 have a common port 2081 and 32 tributary ports 2082, and the add-in cards 209 include add-in modules 212 with 60 input ports. Both the WSS chassis 213 and the add-in card chassis 214 are 32-slot chassis. In the WSS chassis 213, each card occupies two slots, and each card includes a third WSS 208 for adding and removing it. The 32 add-in cards 209 are mounted in two 32-slot chassis, with each add-in card 209 occupying two slots. This allows the components in the add-in assembly to be housed in conventional chassis, enabling customers to retain their investment in the purchased equipment.

[0147] Based on the two examples above, with ROADM node 20 including two dropout components 206, four 32-slot chassis are needed to accommodate 64 dropout cards 209. In the example where P equals 24, for an ITU 50 GHz fixed grid where each fiber can carry 80 wavelengths, the splitting efficiency is (64 × 24) / (60 × 80) = 32%.

[0148] Similarly, with ROADM node 20 including two dropout assemblies 207, four 32-slot chassis are required to accommodate 64 dropout cards 209. In the example where P equals 24, for an ITU 50 GHz fixed grid where each fiber can carry 80 wavelengths, the insertion rate = (64 × 24) / (60 × 80) = 32%.

[0149] In some embodiments, such as Figure 15 and Figure 16 As shown, the ROADM node 20 includes at least one plug-in card frame 215 corresponding to each plug-in assembly. The plug-in card frame 215 includes a middle plate 2151 and slots 2152 located on both sides of the middle plate 2151. At least a portion of the D' third WSSs 208 in the plug-in assembly are installed in the slots 2152 located on one side of the middle plate 2151, and at least a portion of the K plug-in cards 209 in the plug-in assembly are installed in the slots 2152 located on the other side of the middle plate 2151.

[0150] The third WSS 208 and the plug-in card 209 located on both sides of the middle plate 2151 are coupled through the middle plate 2151.

[0151] By using a large chassis to house the third WSS 208 and the plug-in card 209 in the plug-in assembly, the number of chassis used can be reduced.

[0152] For example, such as Figure 15 As shown, the plug-in assembly includes 60 third WSSs 208 and 32 plug-in cards 209. Each third WSS 208 has a common port 2081 and 32 tributary ports 2082. Each plug-in card 209 includes a plug-in module 210 and 15 fourth WSSs 211. The 60 third WSSs 208 are installed in slots 2152 located on the right side of the middle plate 2151, and the 32 plug-in cards 209 are installed in slots 2152 located on the left side of the middle plate 2151.

[0153] For example, such as Figure 16 As shown, the plug-in assembly includes 60 third WSSs 208 and 32 plug-in cards 209. Each third WSS 208 has a common port 2081 and 32 tributary ports 2082. Each plug-in card 209 includes a plug-in module 212 with 60 input ports. The 60 third WSSs 208 are mounted in slots 2152 located on the right side of the middle plate 2151, and the 32 plug-in cards 209 are mounted in slots 2152 located on the left side of the middle plate 2151.

[0154] The above description is merely a specific implementation of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that are readily conceived by those skilled in the art within the technical scope of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A reconfigurable optical add-drop multiplexer (ROADM) node, characterized in that, include: D splitters, wherein each splitter has a common port and N branch ports; Group D first wavelength selection switch WSS, wherein a group of first WSS includes N first WSS, and the first WSS among the N first WSS has a common port and K branch ports; Group D second WSS, wherein a group of second WSS includes N second WSS, and the second WSS among the N second WSS has a common port and K branch ports; D combiners, wherein each combiner has one common port and N branch ports; The common port of the splitter is used to couple to the first optical fiber, and the N branch ports of the splitter are respectively coupled to the common port of the N first WSSs in the group of first WSSs; At least a portion of the K branch ports of the first WSS are respectively coupled to branch ports of a plurality of second WSSs in the D group of second WSSs, and at least a portion of the K branch ports of the second WSS are respectively coupled to branch ports of a plurality of first WSSs in the D group of first WSSs. The common port of the combiner is used to couple to the second optical fiber, and the N branch ports of the combiner are respectively coupled to the common port of the N second WSSs in the group of second WSSs; K is greater than the quotient of D divided by N (K>D / N), N is greater than or equal to 2 (N≥2), and D, N, K, and D / N are all positive integers.

2. The ROADM node according to claim 1, characterized in that, The first WSS in the first group is fully connected to the second WSS in the second group D.

3. The ROADM node according to claim 2, characterized in that, The second WSS in group D includes N clusters, and each cluster includes the second WSS in groups D / N. The D / N branch ports of each first WSS in the group of first WSSs are coupled one-to-one to the branch ports of D / N second WSSs corresponding to each first WSS in the j-th cluster. Any two of the D / N second WSSs in the j-th cluster are located in different groups of second WSSs, where j is a positive integer greater than or equal to 1 and less than or equal to N (1≤j≤N).

4. The ROADM node according to claim 1 or 2, characterized in that, The second WSS in the first group is fully connected to the first WSS in the third group.

5. The ROADM node according to claim 4, characterized in that, The first WSS of group D includes N clusters, and each cluster includes the first WSS of group D / N. The D / N branch ports of each second WSS in the group of second WSSs are coupled one-to-one to the branch ports of the D / N first WSSs corresponding to each second WSS in the i-th cluster. Any two of the D / N first WSSs in the i-th cluster are located in different groups of first WSSs, where i is a positive integer greater than or equal to 1 and less than or equal to N (1≤i≤N).

6. The ROADM node according to any one of claims 1 to 5, characterized in that, K is greater than or equal to 16 (K≥16).

7. The ROADM node according to any one of claims 1 to 6, characterized in that D = N×(K–S'), where K represents the number of branch ports of the first WSS coupled to the second WSS; S' represents the number of branch ports of the first WSS different from the branch ports coupled to the second WSS, and S' is a positive integer less than K (S'<K); the branch ports of the first WSS different from the branch ports coupled to the second WSS include branch ports for add / drop and other branch ports except the branch ports for add / drop and the branch ports coupled to the second WSS.

8. The ROADM node according to any one of claims 1 to 7, characterized in that The splitter is a WSS.

9. The ROADM node according to any one of claims 1 to 8, characterized in that The combiner is a WSS.

10. The ROADM node according to any one of claims 1 to 9, characterized in that The ROADM node includes a plurality of line card frames, and each line card frame includes a plurality of line cards; The line card includes the first WSS in the D groups of first WSSs and / or the second WSS in the D groups of second WSSs.

11. The ROADM node according to claim 10, characterized in that The line card includes one first WSS, one second WSS and one of the D splitters; or The line card includes one first WSS, one second WSS and one of the D combiners; or The line card includes two first WSSs, two second WSSs, one of the D splitters and one of the D combiners; or The line card includes two first WSSs and one of the D splitters; or The line card includes two second WSSs and one of the D combiners.

12. The ROADM node according to any one of claims 1 to 11, characterized in that, Further comprising: At least one add / drop component coupled to S branch ports of the first WSS, where S is less than K (S<K) and S is a positive integer; In the first WSS, the S branch ports coupled to the at least one add / drop component are different from the branch ports coupled to the second WSS.

13. The ROADM node according to any one of claims 1 to 11, characterized in that, Further comprising: At least one add / drop component coupled to T branch ports of the second WSS, where T is less than K (T<K) and T is a positive integer; In the second WSS, the T branch ports coupled to the at least one add / drop component are different from the branch ports coupled to the first WSS.

14. The ROADM node according to claim 12 or 13, characterized in that The add / drop component in the at least one add / drop component includes D' third WSSs and K add / drop cards, and the third WSS in the D' third WSSs has one common port and K branch ports, where D' is a positive integer; The common ports of the D' third WSSs are coupled to the D' branch ports of the plurality of first WSSs or the plurality of second WSSs in a one-to-one correspondence, and the K branch ports of the third WSSs are respectively coupled to the K add-drop cards.

15. The ROADM node according to claim 14, wherein D' is equal to D (D' = D); the common ports of the D third WSSs in the add-drop component are coupled to the D branch ports of D first WSSs or D second WSSs.

16. The ROADM node according to claim 15, wherein For the at least one add-drop component coupled to the S branch ports of the first WSS, the at least one add-drop component includes M add-drop components, where M is a positive integer greater than or equal to 2 and less than or equal to N×S (2 ≤ M ≤ N×S); the D first WSSs coupled to the D third WSSs in the add-drop component are respectively located in the D groups of first WSSs, and the first WSSs in each group of first WSSs are coupled to different add-drop components; For the at least one add-drop component coupled to the T branch ports of the second WSS, the at least one add-drop component includes M' add-drop components, where M' is a positive integer greater than or equal to 2 and less than or equal to N×T (2 ≤ M' ≤ N×T); the D second WSSs coupled to the D third WSSs in the add-drop component are respectively located in the D groups of second WSSs, and the second WSSs in each group of second WSSs are coupled to different add-drop components.

17. The ROADM node according to claim 14, wherein The add-drop card in the K add-drop cards includes an add-drop module having Q input ports and P output ports, and a plurality of fourth WSSs each having a common port and U branch ports; the common port of each fourth WSS is coupled to one of the Q input ports of the add-drop module, and the U branch ports of the fourth WSS are respectively coupled to U third WSSs among the D' third WSSs in the add-drop component; U is less than D' (U < D'), and U, P, and Q are all positive integers; The P output ports of the add-drop module are used for dropping or inserting wavelengths.

18. The ROADM node according to claim 14, wherein The add-drop card in the K add-drop cards includes an add-drop module having Q' input ports and P output ports, and at least some of the Q' input ports of the add-drop module are coupled to the D' third WSSs in the add-drop component in a one-to-one correspondence, where Q' is greater than or equal to D' (Q' ≥ D'), and P and Q' are both positive integers; The P output ports of the add-drop module are used for dropping or inserting wavelengths.

19. The ROADM node according to claim 14, wherein The ROADM node includes at least one WSS chassis and at least one add-drop card chassis corresponding to each add-drop component; The D' third WSSs in the add-drop component are installed in the at least one WSS chassis; The K plug-in cards in the plug-in assembly are mounted in the at least one plug-in card housing.

20. The ROADM node according to claim 14, characterized in that, The ROADM node includes at least one plug-in card frame corresponding to each plug-in component, and the plug-in card frame includes a middle plate and slots located on both sides of the middle plate; At least a portion of the D' third WSSs in the plug-in assembly are installed in slots located on one side of the middle plate; At least some of the K plug-in cards in the plug-in assembly are installed in slots located on the other side of the middle plate.

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