Effective Network for Green Renewable Energy

Abstract

The present disclosure relates to an efficient network for green regenerative energy. A network having a plurality of nodes connected to each other is provided. At least one of the plurality of nodes includes one or more transponders. For example, the transponder may be configured to receive an optical signal having a first set of wavelengths in a first dimension among a plurality of dimensions in the at least one node. The transponder may convert the received optical signal into an electrical signal and then regenerate the optical signal by generating an optical signal having a second set of wavelengths based on the electrical signal. The node may further include one or more switches configured to route the regenerated optical signal to one or more of the plurality of dimensions of the at least one node.

Description

[0001] Division Explanation

[0002] This application is a divisional application of Chinese Patent Application No. 202010547543.0 with an application date of June 16, 2020. Technical Field

[0003] This disclosure relates to an effective network for green renewable energy. Background Art

[0004] Figure 1 An example mesh optical network with several interconnected nodes is shown. Nodes in a mesh optical network can be configured to be colorless (able to receive and / or transmit signals of multiple wavelengths), directionless (able to direct signals in multiple directions), and contentionless (able to receive and / or transmit multiple signals of the same wavelength within the same node). As shown, colorless, directionless, and contentionless ("CDC") networks are typically implemented with one or more reconfigurable optical add-drop multiplexer ("ROADM") nodes. Although not shown, colorless and directionless ("CD") networks can have building blocks similar to CDC networks but with different add / drop structures. Thus, the terms "CD network" and "CDC network" (as well as CD nodes and CDC nodes) can be used interchangeably in the following description. ROADM nodes can be configured to optically route optical signals in multiple directions ("fast paths" or "edges") to other nodes in the network ("fast switching") and to convert optical signals into electrical signals for transmission to a local router ("local termination" or "add / drop"). As the number of nodes and edges increases, for example, with the addition of new infrastructure and new communication channels, the mesh optical network becomes "meshed".

[0005] Although nodes in traditional CDC networks can be contentionless, contention can still occur along the edges between nodes. For example, as Figure 1 shown, the transponder A of node 1 can be configured to transmit an optical signal of wavelength α (channel A) to node 2, while the transponder B of node 1 can also be configured to transmit an optical signal of wavelength α (channel B) to node 3. Thus, the optical signals from transponders A and B may need to share the same edge between node 1 and node 2 along the corresponding fast path between node 1 and node 2, resulting in contention along the shared edge. Although the optical signal for one of the contending channels (such as channel A) can still be transmitted via a different fast path using other edges (e.g., the dashed line through node 5), this fast path may not be the most efficient fast path in the network.

[0006] Figure 2Shows an example ROADM node in a traditional CDC network. As shown, the ROADM node has three "degrees" (labeled "ROADM West", "ROADM East", and "ROADM North"), and each degree can receive incoming signals from other nodes in the network and / or transmit outgoing signals to other nodes in the network. The ROADM node can include a number of optical components and / or electrical components, such as transponders, multiplexers, demultiplexers, switches, amplifiers, etc. For example, a high-performance data center interconnect ("DCI") transponder can be configured to perform optoelectronic conversion on an optical line with relatively high spectral efficiency. A complex add-drop structure ("MUX+DeMUX") can allow transmissions within the node to be CDC. The ROADM node can be configured to maximize optical routing (without converting to or from an electrical signal), such as shown for routing signals between all degrees of the node; and to minimize optoelectronic conversion, such as shown only for local add / drop. As mentioned above, nodes in a CD network can have similar components, but have an add / drop structure different from those shown in Figure 2 the structures shown in.

[0007] Figure 3 Shows an example asymmetric edge connecting nodes along a fast path in a traditional CDC network. The asymmetry can be the result of practical constraints, such as the available locations where the infrastructure can be built. As shown, some edges (such as the relatively long edge between node 1 and node 2) may require more amplifiers than other edges (such as the relatively short edge between node 2 and node 3). Since each amplifier adds noise to the optical signal, the total optical noise along the fast path is the sum of the optical noise accumulated along all the edges within the fast path. Thus, the accumulated noise reduces the spectral efficiency (bits / second / hertz) of data transmission along the fast path. Or in other words, the achievable capacity (bits / second) of the optical signal at a fixed frequency or wavelength along the fast path is reduced due to the accumulated noise. In addition, the wavelength competition along the edge as described above can further reduce the overall spectral efficiency and the achievable capacity for data transmission along the fast path between node 1 and node 3. SUMMARY OF THE INVENTION

[0008] The present disclosure provides a system including one or more transponders and one or more first switches. The one or more transponders can be configured to receive an optical signal having a first set of wavelengths in a first dimension of a plurality of dimensions in a node of a network; convert the received optical signal into an electrical signal; and regenerate the optical signal by generating an optical signal having a second set of wavelengths based on the electrical signal. The one or more first switches can be configured to route the regenerated optical signal to one or more of the plurality of dimensions of the node.

[0009] One or more first switches may include one or more wavelength selective switches (WSSs) configured to route received optical signals to a plurality of ports, each of the plurality of ports being configured to receive one or more wavelengths from a first set of wavelengths.

[0010] One or more first switches may include one or more wavelength selective switches (WSSs) configured to route the regenerated optical signal to another node of the network.

[0011] One or more first switches may include one or more arrayed waveguide gratings (AWGs) configured to route received optical signals to a plurality of ports, each of the plurality of ports being configured to receive one or more wavelengths from a first set of wavelengths.

[0012] The system may further include one or more second switches configured to route a first portion of the received optical signal to a local terminal; and route a second portion of the received optical signal to express switching.

[0013] The system may further include one or more routers connected to the local terminal.

[0014] The system may further include one or more data center interconnect (DCI) transponders configured to convert a first portion of the received optical signal in the local terminal into an electrical signal; and route the electrical signal in the local terminal to one or more routers.

[0015] The system may further include a plurality of ports configured to transmit the electrical signal in the local terminal at corresponding multiple transmission speeds.

[0016] At least one of the one or more transponders may be a ZR transponder.

[0017] The present disclosure further provides a network including a plurality of nodes connected to each other. At least one of the plurality of nodes includes one or more transponders and one or more switches. The one or more transponders may be configured to receive an optical signal having a first set of wavelengths in a first dimension among a plurality of dimensions in a node of the network; convert the received optical signal into an electrical signal; and regenerate the optical signal by generating an optical signal having a second set of wavelengths based on the electrical signal. The one or more switches may be configured to route the regenerated optical signal to one or more of the plurality of dimensions of the node.

[0018] A first node in a network may have a first edge connected to a second node of the network and a second edge connected to a third node of the network, wherein the first edge has a first spectral efficiency and the second edge has a second spectral efficiency, and the first spectral efficiency is higher than the second spectral efficiency.

[0019] The first node may be configured to transmit an optical signal through the first edge at the second spectral efficiency.

[0020] The network may further include an intermediate regeneration node. The intermediate regeneration node may be configured to convert an optical signal from the first node into an electrical signal; regenerate a new optical signal based on the electrical signal; and route the new optical signal to the third node; the intermediate regeneration node may be positioned along the second edge between the first node and the third node such that the difference between the first spectral efficiency and the second spectral efficiency is reduced.

[0021] The first node may further be configured to convert a received optical signal of a first capacity into a first electrical signal; split the first electrical signal into a plurality of electrical signals, each of the plurality of electrical signals having a capacity less than the first capacity; and regenerate the optical signal by converting each of the plurality of electrical signals into a new optical signal to be transmitted through the second edge.

[0022] The second node and the third node may be configured to communicate with each other through an optical signal of a first wavelength along the first edge and an optical signal of a second wavelength along the second edge, wherein the optical signal is converted from the first wavelength to the second wavelength at the first node.

[0023] The present disclosure further provides for receiving an optical signal having a first set of wavelengths in a first dimension of a plurality of dimensions in a node of a network; converting the received optical signal into an electrical signal; and regenerating the optical signal by generating an optical signal having a second set of wavelengths based on the electrical signal; and routing the regenerated optical signal to one or more of the plurality of dimensions of the node.

[0024] The method may further include routing the received optical signal to a plurality of ports, each of the plurality of ports being configured to receive one or more wavelengths of the first set of wavelengths.

[0025] The method may further include routing a first portion of the received optical signal to a local terminal; and routing a second portion of the received optical signal to a fast transfer.

[0026] The method may further include converting a first portion of the received optical signal in the local terminal into an electrical signal; and routing the electrical signal in the local terminal through a router.

[0027] The second portion of the received optical signal may be used in the fast transfer to regenerate an optical signal having a second set of wavelengths. Description of the Drawings

[0028] Figure 1 Shows an example traditional CDC network according to the prior art.

[0029] Figure 2 Shows an example node in a traditional CDC network according to the prior art.

[0030] Figure 3 Shows an example node in a traditional CDC network according to the prior art.

[0031] Figure 4 Shows an example regenerative optical network according to various aspects of the present disclosure.

[0032] Figure 5 Shows an example node in a regenerative optical network according to various aspects of the present disclosure.

[0033] Figure 6 Shows another example node in a regenerative optical network according to various aspects of the present disclosure.

[0034] Figure 7A Shows another example node in a regenerative optical network according to various aspects of the present disclosure.

[0035] Figure 7B Shows another example node in a regenerative optical network according to various aspects of the present disclosure.

[0036] Figure 8 Shows an example asymmetric edge connecting nodes along a fast path in a regenerative optical network according to various aspects of the present disclosure.

[0037] Figure 9A Shows a symmetric edge with an intermediate regeneration node according to various aspects of the present disclosure.

[0038] Figure 9B Shows an example intermediate regeneration node according to various aspects of the present disclosure.

[0039] Figure 10A Shows an example asymmetric edge with a reshaped signal according to various aspects of the present disclosure.

[0040] Figure 10B Shows an example node with reshaped features according to various aspects of the present disclosure.

[0041] Figure 11 Shows an example block diagram of a node in a regenerative optical network according to various aspects of the present disclosure.

[0042] Figure 12 Is a flowchart according to various aspects of the present disclosure. Detailed Description

[0043] Overview

[0044] The technology generally relates to a regenerative optical network. As described above and using Figure 1 as shown, contention can occur along the edges of a traditional CDC network. As the number of nodes in the network increases and as the number of required edges with continuously available spectrum between two nodes increases, some nodes can be completely blocked from reaching each other or at least temporarily blocked from reaching each other until the optical signals traversing those nodes are reconfigured to different wavelengths. Additionally, routing design for optical channels in the network without considering future channel increases can lead to a fragmented network, but it may be difficult or even impossible to predict future channel increases. A fragmented network can result in more blocking edges, which reduces the maximum utilization of the network. For example, the upper limit of a traditional CDC network can be 80% or lower, which is at least partially due to blocking edges. Additionally, since noise accumulates as the optical signal propagates along each edge, the amount of noise in the optical signal also increases as the number of required edges increases. Additionally, Figure 2 the high-performance components (such as DCI transponders and complex add / drop architectures) shown in can be expensive and consume a large amount of energy. Furthermore, in a traditional CDC network, the overall achievable spectral efficiency is reduced because the optical signal traverses all edges along the fast path without optical-to-electrical conversion, so the noise along all edges accumulates in the routed optical signal.

[0045] To address these issues, a regenerative optical network is provided that terminates and regenerates optical signals at nodes of the regenerative optical network. For example, an optical signal having a first wavelength can be received at a node, and once the optical signal is received, it can first be converted into an electrical signal and then converted back into an optical signal having a second wavelength (“regenerated”). The regenerated optical signal having the second wavelength can then be routed along a fast route to another node. Thus, by regenerating the optical signal at the node and even performing fast switching, the optical signal can be converted to a different wavelength to avoid contention along the edges of the regenerative optical network. Thus, in a regenerative optical network, there is no need for a continuous spectrum along multiple edges to transmit an optical signal of a particular channel along the fast path.

[0046] Each node of the regenerative optical network can include one or more transponders configured to perform optical-to-electrical conversion and electrical-to-optical conversion. For example, the transponders can be low-cost and low-energy transponders, such as 400ZR or ZR+ type transponders. An optical signal received at the node can be transmitted to one or more transponders, such as two transponders coupled to each other. The first transponder can convert the received optical signal into an electrical signal, and then the second transponder can convert the electrical signal back into an optical signal.

[0047] The regenerative optical network may further include one or more switches. For example, a switching array (such as a wavelength selective switch (“WSS”) array or an arrayed waveguide grating (“AWG”)) may be configured to route optical signals received from different channels through line ports to different fast paths. The switching may be frequency or wavelength selective, where different wavelengths in the received optical signals may be routed from the line ports to multiple local ports. As another example, one or more switches may be configured to route the received optical signals to local add / drop or fast bypass. The optical signals in the local add / drop may then be converted into electrical signals and transmitted, for example, via a router to servers and / or client devices. In contrast, the optical signals in the fast bypass may be further routed, such as routed to another node of the regenerative optical network. The regenerative optical network may further include other switches configured to direct the regenerated optical signals between various dimensions within the node.

[0048] In a regenerative optical network, each node may have a similar or different configuration. For example, one node in the regenerative optical network may not include any DCI or similar transponders, while another node may include DCI or similar transponders in one or more dimensions of the node. The DCI transponders may be configured to convert optical signals into electrical signals for local add / drop.

[0049] The nodes in the regenerative optical network may further include any one of a number of additional components. For example, a node may additionally include one or more amplifiers. As another example, the local add / drop section in a node may include multiple ports such that electrical signals may be received first at a common port and then split into multiple ports that may have different speeds before being connected to a router.

[0050] In another aspect, the regenerative optical network may further include features that mitigate the impact of noise asymmetry on transmission efficiency and capacity. In one example, a node in the regenerative optical network may be configured to transmit optical signals at a capacity that is the lowest among the achievable capacities along different edges of the fast path. In another example, an edge with a higher achievable capacity in the fast path may be split into multiple edges by one or more additional regenerative nodes. Alternatively, optical signals along an edge carrying a higher data volume may be reshaped into multiple optical signals each carrying a lower data volume, such that the remaining capacity along that edge may be used to transmit other optical signals.

[0051] This technology is advantageous because it provides an energy- and cost-efficient mesh optical network. As described above, the regenerative optical network prevents network fragmentation and blocking to increase edge utilization, which can reach up to 100% in some cases. Since the optical signal is regenerated at each node along the fast path, noise does not accumulate along multiple edges of the fast path. The regenerative optical network also provides features that increase the transmission efficiency and capacity along fast paths with edges that are asymmetric with respect to noise. In addition, compared to traditional CDC networks that use high-performance transponders, the regenerative optical network can use low-energy and low-cost transponders to reduce overall power usage and infrastructure costs. For example, even when low-cost and low-power transponders may have lower performance, the lower performance can be more than compensated for by reducing / eliminating edge-to-edge noise accumulation.

[0052] Example system

[0053] Figure 4 An example regenerative optical network 400 is shown. The regenerative optical network 400 includes multiple nodes, such as nodes 410, 420, 430, 440, 450. The nodes of the regenerative optical network 400 are connected to each other by edges. For example, node 410 is connected to node 420 by edge 462, to node 440 by edge 464, and to node 450 by edge 466. The nodes of the regenerative optical network 400 can transmit optical signals to each other via fast paths that include one or more edges. For example, node 410 can transmit an optical signal to node 420 via fast path 470 that includes only edge 462, while node 410 can transmit an optical signal to node 430 via fast path 480 that includes edge 462 and edge 468. Thus, fast path 470 and fast path 480 share edge 462.

[0054] The regenerative optical network 400 can be configured to terminate and regenerate the optical signal at each node or at least some nodes. For example, an optical signal can be received at node 410, the received optical signal can be converted into an electrical signal, and then converted back into an optical signal before being transmitted to node 420 of the regenerative optical network 400. Thus, instead of directly routing the optical signal in fast switching from one node to another, the optical signal is terminated at each node by being converted into an electrical signal and then "regenerated" into an optical signal at that node for further routing.

[0055] In such a regenerative optical network, contention along an edge can be reduced or eliminated. For example, a first optical signal can be inserted at node 410 (e.g., via local add / drop 412) for transmission along a fast path 470 that includes edge 462 and terminated at node 420. A first wavelength α can be assigned to the first optical signal along edge 462 between nodes 410 and 420, e.g., by configuring a first transponder A at node 410. Later, a second optical signal can be inserted at node 410 via local add / drop 412 for transmission along a fast path 480 that includes edges 462 and 468 and terminated at node 430. A second wavelength β can be assigned to the second optical signal along edge 462, e.g., by configuring a second transponder B at node 410, since wavelength α is already occupied by the first optical signal along edge 462. In this way, potential contention along the shared edge 462 is eliminated.

[0056] In addition, as shown, once node 420 receives the second optical signal having the second wavelength β, node 420 will need to transmit the second optical signal to node 430. However, edge 468 may already be configured to transmit another optical signal having the second wavelength β (e.g., the other optical signal may have been inserted at another node not shown). Thus, the second optical signal needs to be reconfigured for another wavelength. In this regard, the second node 420 can terminate the second optical signal having the second wavelength β and regenerate the optical signal at a third available wavelength via a transponder C. For example, the optical signal regenerated at node 420 can have a third available wavelength γ as shown, or be returned to the first wavelength α (if it is available along edge 468).

[0057] Thus, Figure 4 the shared edge 468 (different from Figure 1 the shared edge) is not blocked for transmission of optical signals from two transponders configured for the same wavelength. Therefore, higher edge utilization is possible in the regenerative optical network 400 compared to Figure 1 conventional CDC networks, up to 100% in some cases (all edges are available for transmission between any pair of transponders). Additionally, the transmission of a single channel along fast path 480 can include the transmission of optical signals having different wavelengths (the second wavelength β along edge 462 and the third wavelength γ along edge 468). Thus, another result is that the transmission of a single channel along a fast path in the regenerative optical network 400 does not require a continuous spectrum along multiple edges.

[0058] In addition, as mentioned above, by terminating the optical signal at each node, the regenerative optical network 400 prevents noise from accumulating along multiple edges along the fast path. For example, an optical signal across the fast path 480 may accumulate a certain amount of noise along the edge 462, but when the optical signal and noise are received at the node, the received optical signal is terminated and regenerated from scratch (from the electrical signal), which does not include the optical noise from the edge 462. Therefore, the regenerated optical signal does not carry the noise from the edge 462 when crossing the edge 468. Therefore, noise accumulation from edge to edge can be completely prevented by regeneration.

[0059] Although only a few nodes are depicted in Figure 4 , it should be understood that a typical regenerative optical network may include a large number of connected nodes. Similarly, although the nodes in Figure 4 are described as having several connections, it should be understood that typical nodes in a regenerative optical network may include a large number of connections. In addition, Figure 4 the relative geographical positioning of the nodes is not depicted.

[0060] To terminate and regenerate the optical signal, the nodes in the regenerative optical network 400 may include several components. Figure 5 An example node 500 in the regenerative optical network is shown, such as the node 420 in the regenerative optical network 400. As shown, the node 500 has three dimensions, ROADM West 510, ROADM North 580, and ROADM East 590, each of which can receive incoming signals from other nodes in the regenerative optical network 400 and / or transmit outgoing optical signals to other nodes in the regenerative optical network 400. For example, ROADM West 510 may be receiving an optical signal from the node 410 and / or transmitting an optical signal to the node 410, ROADM North 580 may be receiving an optical signal from the node 430 and / or transmitting an optical signal to the node 430, and ROADM East 590 may be receiving an optical signal from the node 450 and / or transmitting an optical signal to the node 450.

[0061] Although only a few nodes are depicted in Figure 5 , it should be understood that typical nodes in a regenerative optical network may include a large number of dimensions, such as 16 dimensions. In addition, although the dimensions of the node 500 are labeled "West", "East", and "North", the dimensions do not necessarily correspond to the compass directions. The dimensions may not even correspond to their relative positioning. Instead, these labels only correspond to the way the components are depicted in Figure 5 .

[0062] Referring to Figure 5, an incoming optical signal 512 can be received from node 410 at one or more incoming ports at ROADM West 510. The incoming optical signal 512 can be received from a line port or a common port (not shown) at ROADM West 510, and the incoming optical signal 512 can be dispersed in wavelengths. For example, the incoming optical signal 512 can come from multiple channels of node 410, such as, as Figure 4 shown, a first channel from the first transponder A of node 410 and a second channel from the second transponder B of node 410. Thus, the incoming optical signal 512 can include an optical signal with wavelength α from the first channel and an optical signal with wavelength β from the second channel.

[0063] Accordingly, one or more switches or switching arrays (such as a wavelength selective switch (“WSS”) array 520) can be configured to route optical signals from different channels in the incoming optical signal 512 to their respective fast paths. In this regard, the switching can be frequency or wavelength selective, where the received incoming optical signal 512 can be routed from a common port to multiple local ports or channels (not shown) based on which wavelength(s) each local port is configured to receive. For example, the WSS 520 can be configured to select two optical signals in the received incoming optical signal 512 based on wavelength and route the two selected optical signals to two local ports (two lines out of the WSS 520), where each of the two local ports can be configured to receive one wavelength. In fact, the WSS 520 can select optical signals and route the selected optical signals to many ports (e.g., 32) within node 500, each of which can be configured to receive one or more wavelengths. This wavelength switching (routing) process can be dynamically changed through an electronic communication control interface on the WSS 520.

[0064] Once the incoming optical signal 512 is routed to different ports of different channels, one or more switches can be configured to route the optical signal to local add / drop or express switching. For example, one or more 1×2 switches 530 can be configured to route the optical signal to local add / drop (dashed line) or express switching (solid line). For example, based on the traffic distribution across different geographical locations and / or data centers, some portions of the incoming optical signal 512 can be routed to local add / drop for local traffic, while other portions of the incoming optical signal 512 can be routed to express switching. Then, the optical signal routed to local add / drop can be directly routed to servers and / or client machines. For example, the optical signal can be converted into an electrical signal by a transponder (not shown) (such as a ZR transponder) and then routed by a router 540. In contrast, the optical signal routed to express switching can be further routed, such as to another dimension of the node 500 to be transmitted to another node. In some cases, such as when the traffic in a regenerative optical network is highly asymmetric in terms of volume, 1×N or M×N switches and optical transponders capable of multicasting and / or broadcasting can be used to implement broadcasting and / or multicasting.

[0065] Referring to the optical signals routed for express switching (solid lines from the 1×2 switch 530), one or more transponders can be configured to terminate and regenerate these optical signals. For example, as shown, transponders 550, 552, 554, 556 can be configured to perform optoelectronic conversion on the incoming optical signal 512 received at the ROADM West 510. Additionally, as shown, the transponders can be coupled in pairs. For example, the first transponder 550 can convert the optical signal from the first channel into one or more electrical signals (thick lines). Then, the second transponder 552 coupled to the first transponder 550 can convert the one or more electrical signals back into or regenerate them as an optical signal (solid line). Similarly, the pair of transponders 554 and 556 can perform optoelectronic conversion and electro - optical conversion on the optical signal from the second channel.

[0066] In this regard, the transponder can be any one of a number of transponders. The transponder can be a low-cost and low-energy transponder. For example, as shown, the transponder can conform to standards such as 400ZR or ZR+ type transponders. ZR or ZR+ type transponders are transponders specifically designed to have a much smaller footprint in terms of power consumption and physical size than DCI transponders. For example, in a ZR transponder, the digital signal processing logic can be simplified to a minimum compared to a DCI transponder. In this regard, if a traditional CDC network requires N DCI transponders to achieve the same efficiency or capacity, then the regenerative optical network 400 described herein may require N × (number of edges per node) × (capacity_ZR / capacity_DCI) ZR transponders. Thus, although in some cases more ZR transponders may be required in the regenerative optical network 400 to operate at a performance level comparable to a CDC network with DCI transponders, the low energy and low cost of ZR transponders can still reduce the overall power usage and infrastructure cost.

[0067] Once the electrical signal is regenerated into an optical signal in the rapid transfer, one or more switches 560 can be configured to direct the regenerated optical signal to one or more outgoing ports at one or more dimensions of the node. For example, as Figure 5 shown, a 1×D switch (where D is the number of dimensions of the node, which is 3 in this case) can be configured to direct the regenerated optical signal from the first channel to dimension ROADM North 580, ROADM East 590, or back to ROADM West 510. As another example, a 1×D-1 switch can be configured to direct the regenerated optical signal from the second channel to dimension ROADM North 580 or ROADM East 590.

[0068] Since the outgoing optical signal can also come from more than one channel, one or more switches (such as WSS 522) can be provided on the outgoing side of a certain dimension to combine the optical signals to be sent through the outgoing line ports or common ports. Subsequently, the regenerated optical signal can be transmitted to another node via one or more edges in the fast path described above. For example, the edge can be made up of one or more fiber spans, where each fiber span is an optical fiber followed by an optical amplifier.

[0069] Each dimension in the node can be configured in a similar or different manner. For example, Figure 5ROADM North 580 in is shown to be similar to ROADM West 510 in that the incoming optical signals received at ROADM North 580 are routed through the WSS to multiple ports and then the optical signals are directed to local add / drop (dashed lines) or express transfer (solid lines), where the optical signals in the express transfer are converted into electrical signals by a ZR transponder and regenerated into optical signals. Note that for ease of illustration, various components and lines are omitted from ROADM North 580. For example, the transponder for express transfer for one of the optical signals (for one of the lines from the incoming WSS) is omitted. As another example, the lines representing the regenerated optical signals that would otherwise emerge from switch 1×D-1 to achieve various dimensions in node 500 are omitted.

[0070] ROADM North 580 is shown to be configured in a different manner than ROADM West 510 with respect to the local add / drop section. As shown, a DCI transponder 582 for connecting to a router is provided. The DCI transponder 582 can terminate the optical signal and convert the optical signal into one or more electrical signals for transmission through the router. The connection (not shown) between the DCI transponder 582 and the router in ROADM North 580 can be achieved through one or more copper connections or low-cost short-distance optical modules different from those in ROADM West 510. For example, as mentioned above, the router 540 in ROADM West 510 can be provided with a ZR-based transponder (not shown) for local add / drop for optoelectronic conversion, and the ZR-based transponder is coherent and thus can be directly connected to the router 540.

[0071] Since the number of DCI transponders is reduced compared to the Figure 2 conventional CDC network shown in Figure 5 , the cost and power consumption of the node can be reduced, and thus the regenerated optical network can be reduced. On the other hand, since the DCI transponder can potentially provide higher spectral efficiency, a hybrid network having both ZR and DCI transponders (such as, as shown in Figure 5 ) can further improve the spectral efficiency of the regenerated optical network. In addition, as shown, the Figure 2 switches (such as 1×2 switch 530 and 1×D and 1×D-1 switches 560) replace the

[0072] ROADM East 590 can also be configured in a manner similar to ROADM West 510. Note that, for ease of illustration, most components are omitted from ROADM East 590, including transponders, local add / drop, routers, switches, etc. ROADM East 590 is intended to illustrate that instead of a WSS, one or more switching arrays can be other types of switching arrays, such as arrayed waveguide gratings (“AWGs”). Since the AWG 592 is a passive component that does not allow reconfigurable selection of wavelengths as a WSS does, cost can be saved by using an AWG instead of a WSS in node 500. Node 500 can further include any one of several additional components. For example, as shown, node 500 can additionally include one or more amplifiers, such as amplifier 594.

[0073] Figure 6 , Figure 7A and Figure 7B Alternative configurations of an example node in a regenerative optical network, such as regenerative optical network 400, are shown. Example nodes 600, 700A, and 700B respectively include most of the features of example node 500, but have differences as further discussed below.

[0074] For example, referring to Figure 6 example node 600, for ROADM West 610, the local add / drop section has a different configuration from that of Figure 5 ROADM West 510. As shown, transponders 620, 622, 624, 626 configured for only fast switching for optoelectronic conversion can also be used for local switching. For example, transponder 620 can convert an incoming optical signal into one or more electrical signals and direct the electrical signals to a common port 630. The common port 630 can in turn be connected to a plurality of ports 640 that potentially have different speeds. For example, router 650 can have a port with a speed matching one of the plurality of ports 640. Alternatively, if router 650 does not have a port with a speed matching any of the plurality of ports 640, then the ports with higher speeds may be restricted. Additionally, an AWG is shown in Figure 6 ROADM North 680 (instead of Figure 5 ROADM North 590 in

[0075] Referring to Figure 7A example node 700A, ROADM West 710A is shown as being configured in the same manner as ROADM West 510, but ROADM North 780A is shown as having a configuration different from that of Figure 5Different configurations of ROADM North 580. For example, DCI transponders are not used in ROADM North 780A. Instead, ROADM North 780A uses ZR transponders and is shown to have the same configuration as ROADM West 710A (and ROADM West 510). By not using any DCI transponders, node 700A can further reduce power consumption.

[0076] Referring to Figure 7B , node 700B is shown as a hybrid node including both a regenerating CDC network component and a traditional CDC network component. For example, ROADM West 710B and ROADM North 780B are respectively shown as connected to traditional CDC add / drop structures similar to those shown in Figure 2 . In contrast, ROADM East 790B is shown to have components similar to those of Figure 6 ROADM West 610, including a ZR transponder for regenerating optical signals for fast switching. Note that the signals for local add / drop for ROADM East 790B can also be connected to a traditional CDC add / drop structure. By combining traditional CDC dimensions and add / drop structures with dimensions similar to those described in Figures 5 to 7A , Figure 7B hybrid node 700B can simplify the transition from one system to another. In addition, such a hybrid node can have the ability to be optimized for different routes / paths in a regenerating optical network.

[0077] Although Figure 5 , Figure 6 , Figure 7A , Figure 7B illustrate some example configurations of nodes in regenerating optical network 400, other configurations are possible. Nodes in regenerating optical network 400 can be configured in ways that are similar or different from each other. For example, some nodes in the regenerating optical network can be configured in a similar manner as shown in Figure 2 , while other nodes in the regenerating optical network can be configured in a similar manner as shown in Figures 5 to 7B , such that the entire network becomes a mixture of different types of nodes (including traditional CDC nodes, regenerating nodes, and / or hybrid nodes). As other examples, some nodes of regenerating optical network 400 can include one or more dimensions that only include local termination or fast switching, but not both. Similarly, some nodes of regenerating optical network 400 are configured for only local termination or fast switching rather than for both.

[0078] In another aspect, the regenerating optical network can be configured with features that mitigate the impact of noise asymmetry on transmission efficiency and capacity. As described above with respect to Figure 3As mentioned, in a traditional CDC network, the overall capacity bottleneck can be introduced by the total cumulative noise of all the edges along the fast path. Although such noise accumulation does not occur along the fast path (such as fast path 480) in a regenerative optical network, inefficiencies may be caused by the noise asymmetry along different edges in the fast path.

[0079] For example, Figure 8 An example configuration 800 for mitigating the effects of asymmetric edges is shown. As shown, the fast path (such as fast path 480) connecting nodes 410, 420, and 430 of the regenerative optical network 400 may include edges 462 and 468. As further shown, edges 462 and 468 may be asymmetric, for example, due to practical limitations such as the available locations where the infrastructure can be built. Thus, the relatively long edge 468 may require more amplifiers (which are shown as having amplifiers 812, 813, 814, and 815) than the relatively short edge 462 which is shown as having amplifiers 810 and 811. Since each amplifier adds noise to the optical signal, edges 462 and 468 can be asymmetric in terms of the accumulated optical noise. Thus, data transmission along edge 468 of the fast path 480 may occur at a lower spectral efficiency (bits / second / hertz) than data transmission along edge 462. For example, the achievable capacity (bits / second) of the optical signal in wavelength β can be higher along edge 462 (shown as 400G / s) than along edge 468 (shown as 200G / s).

[0080] Therefore, in Figure 8 the example shown, the nodes connected by the asymmetric edges can be configured to transmit optical signals along the fast path at a capacity that is the lowest standard of the achievable capacity. For example, as shown, nodes 410, 420, and 430 connected by the asymmetric edges 462 and 468 can be configured to transmit optical signals along the fast path 480 at a capacity of 200G / s which is the lowest standard of the achievable capacity. This can be achieved by changing the settings at nodes 410, 420, and / or 430. In this way, rather than the overall capacity utilization being less than the full capacity utilization of 200G / s to 300G / s (for example, less than 80% or less) due to wavelength competition along the edges, the overall capacity of 200G / s can achieve a full utilization of 100%.

[0081] Figure 9AShows another example configuration 900 for using an intermediate regeneration node to mitigate the effects of an asymmetric edge. Example configuration 900 includes most of the features of example configuration 800, but has differences as discussed further below. For example, an intermediate regeneration node (such as intermediate regeneration node 910) can divide a relatively long edge 468 into two edges 920 and 930. Intermediate regeneration node 910 can be configured to terminate and regenerate optical signals in a manner similar to the nodes shown in Figure 5 Figures 7. Intermediate regeneration node 910 can be located between nodes 420 and 430, for example, midway between nodes 420 and 430 or some other available location. As shown, the two newly created edges 920 and 930 each have fewer amplifiers than the original longer edge 468, and thus contribute less noise than the original longer edge 468. Since terminating and regenerating optical nodes prevent optical noise from accumulating through multiple edges, the overall noise along edges 920 and 930 is lower than the noise that would accumulate through the original longer edge 468.

[0082] In Figure 9A the specific example shown, intermediate regeneration node 910 can be positioned such that 300 G / s can be achieved along both edges 920 and 930 (e.g., 300 G / s along edge 920 and 300 G / s along edge 930). Thus, node 410 and shorter edge 462 can be reconfigured (e.g., by changing the settings at node 410) to transmit optical signals at 300 G / s, which is the lowest standard achievable along fast path 480. As another example, when intermediate regeneration node 910 is located at other positions between nodes 420 and 430, different capacities can be achieved along edge 920 and edge 930 (e.g., 400 G / s at both edges), and based on this different capacity, node 410 and shorter edge 462 can be configured (e.g., 400 G / s).

[0083] Figure 9B Shows an example intermediate regeneration node, such as Figure 9A intermediate regeneration node 910. Intermediate regeneration node 910 includes most of the features of example node 500. For example, intermediate regeneration node 910 can include a wavelength selection array (such as AWG 950), which can be designed in a manner similar to AWG 592. For example, AWG 950 can route optical signals of dispersed wavelengths from multiple channels received at a common port to multiple local ports (shown here as two ports). Intermediate regeneration node 910 can include one or more transponders configured to perform optoelectronic conversion, such as transponders 960, 962, 964, 966. Transponders 960, 962, 964, 966 can be similar to Figure 5The repeaters 550, 552, 554, 556 are configured in a similar manner. For example, the repeaters can be coupled in pairs. The first repeater 960 can convert an optical signal from a channel into one or more electrical signals (thick lines). Then, the second repeater 960 coupled to the first repeater 962 can convert the one or more electrical signals back into or regenerate them into an optical signal (solid line).

[0084] The intermediate regeneration node 910 can be configured in a manner different from other regeneration nodes of the regenerative optical network. For example, the intermediate regeneration node 910 can include only the dimensions leading to the nodes where the connection edges are being split. Thus, in this example, the intermediate regeneration node 910 is shown as having two dimensions (dimension 940 leading to node 420 and dimension 980 leading to node 430). Additionally, since the intermediate regeneration node 910 is configured to split only along one direction, no switches are required. Since the intermediate regeneration node 910 is designed to split the edge between two nodes with a fast handover, the intermediate regeneration node 910 may also not include any features for local insertion / drop. As Figure 5 In FIGS. 5 to 7, for ease of illustration, various components and lines are omitted from dimension 980 (which can be configured in a similar manner to dimension 940).

[0085] Figure 10A Another example configuration 1000 for mitigating the effects of asymmetric edges by reshaping optical signals is shown. Example configuration 1000 includes most of the features of example configuration 800 but has differences as further discussed below. For example, Figure 8 Nodes 410 and / or 420 can be reconfigured with features configured to reshape optical signals: as Figure 10A Nodes 1010 and 1020 shown as reshaping. Thus, as shown, the reshaping node 1010 can reshape an optical signal carrying data at 400 G / s to be transmitted through the shorter edge 462 into two reshaped optical signals 1030 and 1040 each carrying data at 200 G / s. In this way, at a given time or time period, one of the reshaped optical signals 1030 or 1040 can be transmitted through edge 468. Thus, the additional 200 G / s capacity along the shorter edge 462 can be used for the transmission of other optical signals. Although reshaping is shown by splitting into two optical signals of equal capacity, in other examples, the optical signal can be reshaped into more than two signals, and / or with the same or different capacities respectively.

[0086] Figure 10B An example node configured to reshape optical signals is shown, such as Figure 10AThe reconditioned node 1010. As shown, the reconditioned node 1010 may include most of the features of the example node 500, such as a switching array, switches, amplifiers, etc. As Figure 5 To FIGS. 7, for ease of illustration, various components and lines are omitted from the dimensions ROADM North 1060 and ROADM East 1070. In addition, only one port is shown at the incoming WSS of ROADM West 1050. As Figure 10B shown, once the incoming optical signal is converted into an electrical signal by the transponder 1080, the electrical signal can be reconditioned into two electrical signals of a smaller capacity by the gearbox 1090. Then the two electrical signals can be regenerated into optical signals respectively by transponders (such as transponders 1082, 1084) and further routed. The transponders 1080, 1082, and 1084 can be configured in a similar manner to Figure 5 the transponders 550, 552, 554, 556. For example, the transponders 1080, 1082, 1084 can be ZR type transponders respectively. Alternatively, a packet processor (such as a switch or a router) can be used to recondition the electrical signal.

[0087] Figure 11 FIG. illustrates an example block diagram of some components in a node (such as node 500 in the regenerative optical network 400) in a regenerative optical network. It should not be regarded as limiting the scope of the present disclosure or the utility of the features described herein. In this example, the node 500 is shown as having one or more computing devices 1100. The computing device 1110 includes one or more processors 1120, a memory 1130, and other components typically present in a general computing device. The memory 1130 of the computing device 1110 can store information accessible by one or more processors 1120, including instructions 1134 that can be executed by one or more processors 1120. For example, as discussed above with respect to Figures 4 to 10B the example shown in, the configuration and reconfiguration of the regenerative optical network can be performed by one or more processors 1120 according to the instructions 1134 and data 1132 in the memory 1130.

[0088] The memory 1130 may also include data 1132 that can be retrieved, manipulated, or stored by the processor. The memory can be of any non-transitory type capable of storing information accessible by the processor, such as a hard disk drive, a memory card, ROM, RAM, DVD, CD-ROM, write-capable and read-only memory.

[0089] One or more processors 1120 may retrieve, store, or modify data 1132 according to instructions 1134. For example, although the subject matter described herein is not limited to any particular data structure, the data may be stored in computer registers, stored in a relational database as a table with many different fields and records, or an XML document. The data may also be formatted in any computer device-readable format, such as but not limited to binary values, ASCII, or Unicode. Additionally, the data may include any information sufficient to identify the relevant information, such as numbers, descriptive text, appropriate codes, pointers, references to data stored in other memories (such as stored at other network locations), or information used by a function for computing the relevant data. As shown, the data 1132 may include data regarding the various components of node 500 and the regenerative optical network 400.

[0090] The instructions 1134 may be any set of instructions to be directly executed by one or more processors, such as machine code; or any set of instructions to be indirectly executed by one or more processors, such as a script. In this regard, the terms "instructions", "application", "step", and "program" may be used interchangeably herein. The instructions may be stored in a target code format for direct processing by the processor or stored in any other computer device language (including interpreted-on-demand or pre-compiled scripts or class sets of independent source code modules). As shown, the instructions 1134 may include functions or methods for controlling the various components of node 500 to perform routing, switching, etc.

[0091] One or more processors 1120 may be any conventional processor, such as a commercially available CPU. Alternatively, the processor may be a specialized component, such as an application specific integrated circuit ("ASIC") or other hardware-based processor. Although not required, one or more of the computing devices 1110 may include specialized hardware components for performing particular computing processes.

[0092] Although Figure 11Functionally, the processor, memory, and other elements of computing device 1110 are illustrated as being within the same block, but the processor, computer, computing device, or memory can actually include multiple processors, computers, computing devices, or memories that may or may not be stored within the same physical housing. For example, the memory can be a hard disk drive or other storage medium located in a housing different from the housing of computing device 1110. Accordingly, references to a processor, computer, computing device, or memory will be understood to include references to a collection of processors, computers, computing devices, or memories that may or may not operate in parallel. For example, computing device 1110 can include server computing devices operating as a load-balanced server farm, a distributed system, and the like. Still further, although some of the functionality described below is indicated as occurring on a single computing device having a single processor, aspects of the subject matter described herein can be implemented by multiple computing devices, such as by transmitting information over a network.

[0093] Computing device 1110 may be capable of communicating directly and indirectly with other nodes of the regenerative optical network 400. Computing devices in the regenerative optical network 400, such as computing device 1100, can be interconnected using a variety of protocols and systems such that the computing devices in the regenerative optical network 400 can be part of the Internet, the World Wide Web, a particular intranet, a wide area network, or a local area network. Computing devices in the network can utilize standard communication protocols such as Ethernet, WiFi, and HTTP, one or more company-proprietary protocols, and various combinations of the foregoing. Although certain advantages are generally obtained when transmitting or receiving information as mentioned above, other aspects of the subject matter described herein are not limited to any particular manner of transmitting information.

[0094] Example methods

[0095] In addition to the example systems described above, example methods are now described. Such methods can be performed using any one of the systems described above, modifications thereof, or various systems having different configurations. It should be understood that the operations involved in the following methods need not be performed in the exact order described. Instead, the various operations can be processed in a different order or simultaneously, and operations can be added or omitted.

[0096] For example, Figure 12 An example flowchart that can be performed by a regenerative optical network, such as regenerative optical network 400, is shown. For example, nodes in the regenerative optical network 400, such as nodes 500, 600, 700A, or 700B, can receive optical signals and route the optical signals to other nodes in the regenerative optical network 400. In some cases, the flowchart can be performed at least in part by a computing device in the regenerative optical network 400, such as Figure 11 the computing device 1100 shown in

[0097] Refer to Figure 12 , in block 1210, a first dimension among multiple dimensions in a node of a network receives an optical signal having a first set of wavelengths. For example, as Figure 5 shown in, an incoming optical signal 512 can be received in dimension ROADM West 510.

[0098] In block 1220, the received optical signal is converted into an electrical signal. In this regard, one or more transponders can convert the received optical signal into an electrical signal. For example, as Figure 5 shown in, transponders 550 and 552 are shown as being coupled, where transponder 550 can be configured to convert incoming optical signal 512 into an electrical signal.

[0099] In block 1230, an optical signal having a second set of wavelengths is generated based on the electrical signal, thereby generating a "regenerated" optical signal. For example, as Figure 5 shown in, transponders 550 and 552 are shown as being coupled, where transponder 552 can be configured to convert the electrical signal from transponder 550 into an optical signal. The regenerated signal can have any wavelength, including having the same wavelength as the incoming optical signal or a different wavelength from the incoming optical signal.

[0100] In block 1240, the regenerated optical signal is routed to one or more of multiple dimensions of the node. In this regard, one or more switches can be configured to route the regenerated optical signal. For example, as Figure 5 shown in, one or more switches 560 can be configured to route the regenerated optical signal to one or more of dimension ROADM North 580, ROADM East 590, and / or ROADM West 510.

[0101] In some cases, the received optical signal can be routed to multiple ports, each of which is configured to receive one or more wavelengths from the first set of wavelengths. One or more switches can be configured to perform the routing. For example, as Figure 5 shown in, a switch array (such as WSS 520 and AWG 592) can route incoming optical signal 512 to different ports within node 500.

[0102] Additionally, a first portion of the received optical signal can be routed to a local terminal, while a second portion of the received optical signal is routed to express switching. One or more switches can be configured to perform the routing. For example, as Figure 5 shown in, switch 530 can be configured to route incoming optical signal 512 to a local terminal, for example, convert it into an electrical signal for transmission to router 540. Alternatively or additionally, as Figure 6As shown, once converted into an electrical signal, the electrical signal can be divided into different ports 640, 642 having different speeds before being connected to a router. In addition, as Figure 5 shown, switch 530 can be configured to route incoming optical signal 512 to express grooming, for example, converted and regenerated by transponders 550 to 556, and further routed through switch 560 to ROADM North 580, ROADM East 590, etc.

[0103] In another aspect as described above with respect to Figures 8 to 10B an additional method can be used to mitigate the impact of noise asymmetry on transmission efficiency and capacity. In the Figure 8 example shown, an optical signal can be transmitted at a capacity that is the lowest among the achievable capacities along different edges of the express path. In the Figures 9A to 9B example shown, an edge having a higher achievable capacity in the express path can be split into multiple edges by one or more additional regeneration nodes. Alternatively, in the Figures 10A to 10B example shown, an optical signal along an edge carrying a higher data volume can be reshaped into multiple optical signals each carrying a lower data volume, so that the remaining capacity along that edge can be used to transmit other optical signals.

[0104] This technique is advantageous because it provides an energy - and cost - efficient mesh optical network. As described above, the regenerative optical network prevents network fragmentation and blocking to increase edge utilization, which in some cases can reach up to 100%. Since the optical signal is regenerated at each node along the express path, noise does not accumulate along multiple edges of the express path. The regenerative optical network also provides features that increase the transmission efficiency and capacity along the express path of edges that are asymmetric with respect to noise. In addition, compared to traditional CDC networks using high - performance transponders, the regenerative optical network can use low - energy and low - cost transponders to reduce overall power usage and infrastructure costs.

[0105] Unless otherwise specified, the foregoing alternative examples are not mutually exclusive, but can be implemented in various combinations to achieve unique advantages. Since these and other variations and combinations of the features discussed above can be utilized without departing from the subject matter defined by the claims, the foregoing description of the embodiments should be made by way of illustration of the subject matter defined by the claims rather than by way of limitation. Additionally, the provision of the examples described herein and words such as "such as", "including", etc. should not be construed as limiting the subject matter of the claims to specific examples; rather, the examples are merely intended to illustrate one of many possible embodiments. Furthermore, the same reference numerals in different figures can identify the same or similar elements.

Claims

1. A network, comprising: A first node, the first node having a first edge connected to a second node and a second edge connected to a third node, wherein the first edge has a first spectral efficiency and the second edge has a second spectral efficiency, the first spectral efficiency being higher than the second spectral efficiency, and wherein the first node is further configured to: Convert a received optical signal of a first capacity into a first electrical signal; Split the first electrical signal into a plurality of electrical signals, each of the plurality of electrical signals having a capacity less than the first capacity; Regenerate an optical signal by converting each of the plurality of electrical signals into a new optical signal to be transmitted through the second edge.

2. The network according to claim 1, wherein, The second node and the third node are configured to communicate with each other via an optical signal of a first wavelength along the first edge and an optical signal of a second wavelength along the second edge, wherein the optical signal is converted from the first wavelength to the second wavelength at the first node.

3. The network according to claim 1, wherein, The second node and the third node are configured to communicate with each other via an optical signal of a first wavelength along the first edge and an optical signal of a second wavelength along the second edge, wherein the optical signal is converted from the first wavelength to the second wavelength at the first node.

4. The network according to claim 1, wherein the first node comprises: One or more transponders, the one or more transponders being configured to: Receive an optical signal having a first set of wavelengths in a first dimension among a plurality of dimensions in the first node; Convert the received optical signal into an electrical signal; And Regenerate the optical signal by generating an optical signal having a second set of wavelengths based on the electrical signal; And One or more switches, the one or more switches being configured to route the regenerated optical signal to one or more of the plurality of dimensions of the first node.

5. The network according to claim 4, wherein, The one or more switches include one or more wavelength selective switches (WSS), the one or more wavelength selective switches (WSS) being configured to route the received optical signal to a plurality of ports, each port being configured to receive one or more wavelengths of the first set of wavelengths and route the regenerated optical signal to another node of the network.

6. The network according to claim 4, wherein, The one or more switches include one or more arrayed waveguide gratings (AWG), the one or more arrayed waveguide gratings (AWG) being configured to route the received optical signal to a plurality of ports, each port being configured to receive one or more wavelengths of the first set of wavelengths.

7. The network according to claim 4, wherein, The first node further includes: One or more second switches, the one or more second switches being configured to: Route a first portion of the received optical signal to a local terminal; and Route a second portion of the received optical signal to fast switching.

8. The network according to claim 7, wherein, The first node further includes: One or more data center interconnect (DCI) transponders, the one or more data center interconnect (DCI) transponders being configured to: Convert the first portion of the received optical signal in the local terminal into an electrical signal; and Route the electrical signal in the local terminal to one or more routers.

9. The network according to claim 4, wherein, The first node further includes: A plurality of ports, the plurality of ports being configured to transmit electrical signals in the local terminal at corresponding multiple transmission speeds.

10. The network according to claim 4, wherein, At least one of the one or more transponders is a ZR transponder.

Images