CN111953444A

CN111953444A - Optical network system, scheduling method thereof and data center interconnection network

Info

Publication number: CN111953444A
Application number: CN201910399475.5A
Authority: CN
Inventors: 谢崇进; 窦亮; 张欢; 陈赛
Original assignee: Alibaba Group Holding Ltd
Current assignee: Alibaba Group Holding Ltd
Priority date: 2019-05-14
Filing date: 2019-05-14
Publication date: 2020-11-17
Also published as: WO2020228674A1

Abstract

The embodiment of the application provides an optical network system, a scheduling method thereof and a data center interconnection system. In the embodiment of the application, the optical network system comprises a plurality of sub-networks, wherein at least one of the sub-networks comprises a ROADM, at least one of the sub-networks except the sub-network comprising the ROADM comprises a light path selector, and the sub-networks are optically interconnected with the light path selector through the ROADM. Therefore, between the sub-networks which realize optical connection through the ROADM, the optical connection between the sub-networks can be realized without adopting a straight-through optical link connection, the number of the optical links can be reduced, the interconnection structure of an optical network system can be simplified, and the network cost can be reduced.

Description

Optical network system, scheduling method thereof and data center interconnection network

Technical Field

The present application relates to the field of optical communications technologies, and in particular, to an optical network system, a scheduling method thereof, and a data center interconnection network.

Background

Optical interconnections between data centers, in particular between data centers in a metropolitan area network, mostly use point-to-point direct connections, i.e. there is a direct optical fiber line connection between every two data centers. With the expansion of the cloud computing scale, the number of data centers is more and more, in this case, an optical network with N data centers needs N (N-1)/2 optical links, the number of optical links and the number of data centers are in a square relationship, the number of required optical links is larger, and the cost of the whole network is higher.

Disclosure of Invention

Aspects of the present disclosure provide an optical network system, a scheduling method thereof, and a data center interconnection network, so as to reduce the number of optical links in the optical network system, thereby reducing the cost of the entire network.

An embodiment of the present application provides an optical network system, including: a plurality of sub-networks; wherein, at least one sub-network in the plurality of sub-networks comprises a reconfigurable optical add-drop multiplexer ROADM, and at least one sub-network in other sub-networks except the ROADM sub-network comprises an optical path selector; and the plurality of sub-networks are optically connected with the optical path selector through the ROADM.

An embodiment of the present application further provides a data center interconnection network, including: comprises a plurality of data centers DC; at least two DCs in the plurality of DCs comprise reconfigurable optical add-drop multiplexers (ROADMs), and other DCs except the at least two DCs comprise optical path selectors; and each two ROADMs and each optical path selector and each ROADM are connected through optical links.

The embodiment of the present application further provides a scheduling method of an optical network system, including:

monitoring the link state of an optical link comprising a ROADM and/or comprising an optical path selector in an optical network system;

when a link failure is detected, controlling a target optical path selector or a target ROADM on a failed original link to switch from the original link to a non-failed link, and controlling the ROADM on the non-failed link to forward an optical signal from the target optical path selector or the target ROADM.

In the embodiment of the application, the optical network system comprises a plurality of sub-networks, wherein at least one of the sub-networks comprises a ROADM, at least one of the sub-networks except the sub-network comprising the ROADM comprises a light path selector, and the sub-networks are optically interconnected with the light path selector through the ROADM in the optical network system. Therefore, between the sub-networks which realize optical connection through the ROADM, direct optical link connection is not needed, the optical connection between the sub-networks can be realized, the number of the optical links can be reduced, the interconnection structure of an optical network system is simplified, and the network cost is reduced.

On the other hand, because the ROADM and the optical path selector have the optical path switching function, when an optical link between sub-networks interconnected through the ROADM and the optical path selector fails, the communication link can be switched to other normal optical links through the ROADM or the optical path selector corresponding to the failed link, which is beneficial to ensuring the normal operation of the optical network system, improving the scheduling capability and the network recovery capability of the optical network, and further improving the communication performance of the optical network system. In addition, the optical path selector has lower cost compared with the ROADM, and the optical path selector is adopted by a part of sub-network, so that the network cost can be further reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1a is a schematic structural diagram of an optical network system according to an embodiment of the present application;

fig. 1b is a schematic structural diagram of another optical network system according to an embodiment of the present application;

fig. 1c is a schematic structural diagram of another optical network system according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a ROADM according to an embodiment of the present disclosure;

fig. 3a is a schematic structural diagram of an optical path selector according to an embodiment of the present disclosure;

fig. 3b is a schematic structural diagram of another optical path selector according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a data center interconnection network according to an embodiment of the present application;

fig. 5 is a flowchart illustrating a method for scheduling an optical network system according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to solve the technical problems of a large number of optical links and high cost of an existing optical network system, some embodiments of the present application provide an optical network system, where the optical network system includes a plurality of sub-networks, at least one of the sub-networks includes a ROADM, at least one of the other sub-networks except the sub-network including the ROADM includes an optical path selector, and the sub-networks are optically connected to the optical path selector through the ROADM in the optical network system. Thus, between the sub-networks which realize optical connection through the ROADM, the optical connection between the sub-networks can be realized without adopting a straight-through optical link connection, the number of the optical links can be reduced, the interconnection structure of the optical network system can be simplified, and the network cost can be reduced.

On the other hand, because the ROADM and the optical path selector have the optical path switching function, when an optical link between sub-networks interconnected through the ROADM and the optical path selector fails, the communication link can be switched to other normal optical links through the ROADM or the optical path selector corresponding to the failed link, which is beneficial to ensuring the normal operation of the optical network system and improving the communication performance of the optical network system.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Fig. 1a is a schematic structural diagram of an optical network system according to an embodiment of the present application. As shown in fig. 1a, the optical network system includes: a plurality of sub-networks. In the embodiments of the present application, a plurality means 3 or more than 3, for example, 4, 5, 10, and the like. Fig. 1a illustrates the number of subnetworks as 6, but the number is not limited thereto. For multiple sub-networks, at least one of the sub-networks includes a Reconfigurable Optical Add-Drop Multiplexer (ROADM), such as sub-network 100c in fig. 1 a. Further, in the optical network system, at least one of the sub-networks other than the sub-network including the ROADM includes a light path selector, such as sub-networks 100a, 100b, 100e, and 100f in fig. 1 a. In fig. 1a, only 1 sub-network including ROADMs and 4 sub-networks including optical path selectors are illustrated, but the number is not limited thereto.

Optionally, the optical network system may further include: a sub-network that contains neither ROADMs nor optical path selectors, such as sub-network 100d in fig. 1 a. A sub-network that contains neither ROADMs nor optical path selectors refers to a sub-network that does not have optical path selection capability, and that includes conventional connectors and is optically connected to other sub-networks through the conventional connectors. The traditional connector has no optical path selection capability and has a fixed channel connection relationship. For example, a conventional connector may include: MUX/DEMUX and optical amplifier, wherein, optical amplifier is optional device.

In this embodiment, optical connections between subnetworks in the optical network system may be made through the ROADM and the optical path selector. Wherein, each sub-network containing the optical path selector can be optically connected with the ROADM in the sub-network containing the ROADM through the optical path selector contained in the sub-network. Alternatively, if there is a sub-network containing legacy connectors in the optical network system, the sub-network containing legacy connectors may make optical connections with ROADMs in the sub-network containing ROADMs through the legacy connectors it contains. Of course, the sub-network including the conventional connector may also perform optical connection with the sub-network including the optical path selector through the conventional connector included in the sub-network, and the optical connection condition between the sub-networks may be determined according to the interconnection requirement of the optical network system, which is not limited in this embodiment. For example, in FIG. 1a, sub-networks 100b, 100e, and 100f are optically connected to sub-network 100d in addition to sub-network 100 c. Therefore, the sub-networks which realize optical connection through the ROADM do not need to adopt direct optical link connection, the optical connection between the sub-networks can be realized, the number of optical links can be reduced, the connection structure of an optical network system is simplified, and the network cost is reduced.

It should be noted that in the embodiments of the present application, the "optical connection" may be a connection through any optical link, for example, a connection through an optical fiber, a connection through an optical waveguide, or a connection through spatial optical coupling, but is not limited thereto.

Further, in this embodiment, the sub-network including ROADM can implement Hub function, and has cross-scheduling capability for optical channels. Furthermore, the optical path selector has an optical link switching function, and is matched with the Hub function of the ROADM, so that when an optical link between sub-networks optically connected through the ROADM and the optical path selector fails, the communication link can be switched to other normal optical links through the ROADM or the optical path selector corresponding to the failed link, the normal operation of an optical network system is favorably ensured, the scheduling capability and the network recovery capability of the optical network are improved, and the communication performance of the optical network system is further improved. For example, as shown in fig. 1a, if the optical link between the sub-network 100c and the sub-network 100b fails, the communication between the sub-network 100c and the sub-network 100b can be switched to the optical link via the sub-network 100c, the sub-network 100d, and the sub-network 100b, and so on. The following embodiments will be described in detail with respect to the specific implementation of performing optical link switching when an optical link between subnetworks fails, and will not be described in detail here.

In order to further reduce the number of optical links of the optical network system and improve the scheduling capability and the network recovery capability of the optical network system. The number of sub-networks including ROADMs in the optical network system provided by the embodiment of the present application may be at least 2; and the sub-networks other than the ROADM include optical path selectors. Such an optical network system is exemplified below.

Fig. 1b is a schematic structural diagram of another optical network system according to an embodiment of the present application. As shown in fig. 1b, the system comprises: a plurality of sub-networks. Wherein, a plurality means 3 or more. Fig. 1b illustrates only 8 subnetworks, but is not limited thereto. For multiple sub-networks, at least two of which contain ROADMs, such as sub-networks 10a, 10e, and 10f in fig. 1 b; the sub-networks other than the at least two sub-networks comprising the ROADM each comprise a light path selector, e.g. sub-networks 10b, 10c, 10d and sub-networks 10g and 10h in fig. 1 b. In fig. 1b, only 3 sub-networks including ROADMs and 5 sub-networks including optical path selectors are illustrated, but the number is not limited thereto.

In this embodiment, optical connections are made between a plurality of sub-networks in the optical network system through ROADMs in at least two sub-networks and optical path selectors in other sub-networks. For example, in FIG. 1b, sub-networks 10a-10g are optically interconnected with the optical path selectors in sub-networks 10b, 10c, 10d and sub-networks 10g and 10h by ROADMs in sub-networks 10a, 10e and 10 f.

In the optical network system provided in this embodiment, at least two sub-networks include ROADMs, other sub-networks include optical path selectors, and optical connections are made between the sub-networks of the optical network system through the ROADMs in the at least two sub-networks and the optical path selectors in the other sub-networks. Therefore, each sub-network including the optical path selector can be optically connected through the ROADM, optical connection between the sub-networks can be realized without adopting a straight-through optical link for optical connection, the number of the optical links can be reduced, a network system is simplified, and network cost is reduced.

Further, in this embodiment, the sub-network including ROADM can implement Hub function, and has cross-scheduling capability for optical channels. Furthermore, the optical path selector has an optical link switching function and is matched with the Hub function of the ROADM, so that when an optical link between some sub-networks fails, the communication link can be switched to other normal optical links connected with the ROADM or the optical path selector corresponding to the failed link, the normal operation of an optical network system is favorably ensured, the scheduling capability and the network recovery capability of the optical network are improved, and the communication performance of the optical network system is further improved. For example, as shown in FIG. 1b, if an optical link between sub-networks 10a and 10b fails, communications between sub-networks 10a and 10b may be switched to an optical link that is relayed via sub-network 10f to enable communications between sub-networks 10a and 10b, and so on. The following embodiments will be described in detail with respect to the specific implementation of performing optical link switching when an optical link between subnetworks fails, and will not be described in detail here.

Further, in this embodiment, the sub-networks of the optical network system are not all constructed by ROADM, but part of the sub-networks are constructed by ROADM, and part of the sub-networks are constructed by using relatively low-priced optical path selectors, so that the network cost can be further reduced.

It should be noted that the connection manner between the sub-networks 10a-10g shown in fig. 1b is only an exemplary illustration, and any connection manner that realizes connection between a plurality of sub-networks in the optical network system by optically connecting with optical path selectors in other sub-networks except at least two sub-networks through ROADMs in at least two sub-networks is included in the optical network system provided in the embodiments of the present application, for example, Mesh network connection. In the following, a Mesh network is taken as an example to illustrate a connection manner between sub-networks in an optical network system.

As shown in fig. 1c, when the optical network system is a Mesh network, each two ROADMs in the optical network system are connected by an optical link, and each optical path selector and each ROADM in the optical network system are connected by an optical link. Because each optical path selector is connected with all the ROADMs through the optical links, the fault recovery capability of the optical network system can be further improved, wherein the more the number of the ROADMs is, the stronger the fault recovery capability of the optical network system is. For example, in fig. 1c, 4 sub-networks containing optical path selectors (sub-networks 11a, 11b and sub-networks 11e, 11f) are optically connected to each sub-network containing ROADM. Fig. 1c is only illustrated with 2 sub-networks comprising ROADMs and 4 sub-networks comprising optical path selectors, without limiting the number thereof.

It is worth noting that in the embodiment of the present application, various types of ROADMs can be adopted as the ROADMs. For example, wavelength-dependent and direction-dependent (chromatic and direction) ROADMs, wavelength-independent and direction-dependent (chromatic and direction) ROADMs, wavelength-dependent and direction-independent (chromatic and direction) ROADMs, wavelength-independent and direction-independent (chromatic and direction) ROADMs, or wavelength-independent, direction-independent and competition-independent (chromatic and direction) ROADMs (CD-ROADMs), may be used. Preferably, a CD-ROADM or a CDC-ROADM may be used, which may improve the flexibility of optical channel scheduling in the optical network system.

Further, as shown in fig. 2, the CD-ROADM includes: a local optical Wavelength selector (WSS) module 20a and at least one external WSS module 20 b. Wherein the local WSS module 20a is optically connected to each of the external WSS modules 20b and to each of the two external WSS modules. Further, when a sub-network including ROADM in the optical network system adopts CD-ROADM, each external WSS module 20b is also optically connected to an optical path selector or an external WSS module in another RAODM through an optical link.

Further, as shown in fig. 2, the local WSS module 20a includes: a drop WSS20 a1 and an add WSS20a 4. Each of the external WSS modules 20b also includes: a drop WSS20 b1 and an add WSS20b 2. The uplink refers to wavelength signal transmission, that is, a path for loading a digital signal onto an optical signal and transmitting the optical signal from an optical link; the downlink refers to wavelength signal reception, that is, receiving an optical signal from an optical link, and demodulating or forwarding the optical signal to another external optical link. Further, the upper WSS20a4 and the lower WSS20 a1 in the local WSS module 20a are respectively optically connected with the upper WSS20b2 and the lower WSS20 b1 of each external WSS module 20b, i.e., the upper WSS20a4 in the local WSS module 20a is respectively optically connected with the upper WSS20b2 in each external WSS module 20 b; the drop WSS20 a1 in the local WSS module 20a is optically connected to the drop WSS20 b1 in each of the outbound WSS modules 20b, respectively.

Further, between every two external WSS modules, an upper WSS in each external WSS module is optically connected with a lower WSS in the other external WSS module; the downstream WSS in each external WSS module is optically connected with the upstream WSS in another external WSS module. As shown in fig. 2, the upper WSS20b2 in the north external WSS module is optically connected with the lower WSS20 b1 in the west external WSS module and is optically connected with the lower WSS in the east external WSS module (not labeled in fig. 2); the down WSS20 b1 in the north external WSS module is optically connected to the up WSS20b2 in the west external WSS module and to the up WSS in the east external WSS module (not labeled in fig. 2). Further, the add WSS20b2 and the drop WSS20 b1 in each external WSS module are optically connected to an optical path selector in another sub-network or an external WSS module in a ROADM via optical links.

Further, for wavelength add (wavelength signal transmission) of the local WSS module 20a, the input end of the upper WSS20a4 is connected to the optical combiner 20a6, which is used to combine the optical signals received from the optical termination array and send them to the upper WSS20a4, and then the optical signals are forwarded to other sub-networks by the upper WSS20a4 via optical links, so as to implement wavelength division multiplexing of the optical links. Further, an optical amplifier 20a5 is connected between the input end of the add WSS20a4 and the optical combiner, and is configured to perform power amplification on the combined optical signal, so as to compensate for losses caused by the add WSS20a4, the optical combiner 20a6, and an optical link therebetween.

For wavelength drop (wavelength signal reception) of the local WSS module 20a, the output end of the drop WSS20 a1 is connected to the optical splitter 20a3, which is used to perform power average distribution on the optical signal output by the drop WSS20 a1, and then output the optical signal to each optical terminal in the optical terminal array, so that the optical terminals independent of each wavelength receive the drop wavelength signal. The optical splitter 20a3 may be a1 × N optical coupler, where N represents the number of output ends of the optical coupler, and the specific value thereof can be flexibly set according to the number of optical terminals in the optical terminal array. Further, an optical amplifier 20a2 is connected between the output end of the downstream WSS20 a1 and the optical splitter 20a3, and is configured to perform power amplification on the optical signal output by the downstream WSS20 a1, so as to compensate for loss caused by the downstream WSS20 a1, the optical splitter 20a3 and optical connection therebetween, and output the optical signal after power amplification to the optical splitter 20a 3. For example, the drop WSS20 a1 and the splitter 20a3 are connected by optical fibers, which compensates for losses caused by the drop WSS20 a1 and the splitter 20a3 and the fiber connection therebetween.

Further, as shown in fig. 2, for each external WSS module 20b, the input end of the down WSS20 b1 and the output end of the up WSS20b2 are connected with optical amplifiers (shown as triangles in fig. 2). The optical amplifier connected to the drop WSS20 b1 in the external WSS module 20b is configured to perform power amplification on an optical signal received from the optical link, compensate for line loss caused by the optical link, and transmit the optical signal after power amplification to the drop WSS20b 1; the optical amplifier connected to the add WSS20b2 in the external WSS module 20b is configured to perform power amplification on the optical signal output by the add WSS20b2, compensate for loss caused by optical connection inside the add WSS and the ROADM, amplify the optical signal to a required power level, and transmit the power-amplified optical signal to the optical path selector of another sub-network connected to the add WSS20b2 or the external WSS module in the ROADM via the optical link.

In the embodiment of the present application, each Optical Amplifier may use an Erbium-doped Fiber Amplifier (EDFA) or a Semiconductor Optical Amplifier (SOA), but is not limited thereto.

In the embodiment of the application, each WSS can forward the specified wavelength from the specified input port to the specified output port according to actual needs, so as to realize a wavelength forwarding function, and each WSS also has a function of power balance among wavelengths. The complexity of a WSS is determined by the number of wavelengths that can be reconfigured and the number of input and output ports.

Alternatively, in the embodiment of the present application, the optical path selector may be any structure that can implement optical channel scheduling. The following is an exemplary description of an embodiment of the optical path selector.

In one embodiment, as shown in fig. 3a, the optical path selector may include: and a WSS module. The WSS module is optically connected to each ROADM in its optical network system via an optical link. For the optical network system provided in the embodiment of the present application, since there are at least two sub-networks including ROADMs, the WSS module may be optically connected to the ROADMs in the at least two sub-networks through optical links. For example, for the optical network system shown in FIG. 1b, the WSS modules in sub-network 10c are optically connected to ROADMs in sub-networks 10a, 10e, and 10f via optical links; the WSS modules in sub-network 10b are optically connected to ROADMs in sub-networks 10a and 10f via optical links.

Further, as shown in fig. 3a, the WSS module includes: a drop WSS 30a1 and an add WSS 30a 4. Wherein each output port of the add WSS 30a4 is optically connected to one ROADM via an optical link, and each input port of the drop WSS 30a1 is optically connected to one ROADM via an optical link. In fig. 3a, it is only shown that the WSS modules are in optical connection with 2 ROADMs, i.e. 2 output ports of the add WSS 30a4 and 2 input ports of the drop WSS 30a1 are in optical connection with 2 ROADMs, respectively.

Further, for the wavelength add path of the WSS module, the input end of the upper WSS 30a4 is connected to the optical combiner 30a6, which is used to combine the optical signals received from the optical termination array and send them to the upper WSS 30a4 for wavelength selection and forwarding, and send the designated signals to the subnetwork of the opposite end through the optical link, thereby implementing wavelength division multiplexing of the optical link. Further, an optical amplifier 30a5 is connected between the input end of the add WSS 30a4 and the optical combiner 30a6 for power amplifying the combined optical signal and compensating for the loss caused by the add WSS 30a4, the optical combiner 30a6 and the optical connection therebetween.

For the wavelength drop of the local WSS module 30a, the output end of the drop WSS 30a1 is connected to an optical splitter 30a3, which is used to distribute the power of the optical signal output by the drop WSS 30a1 evenly and then send the optical signal to each optical terminal in the optical terminal array, and the optical terminals independent of each wavelength receive the drop wavelength signal. The optical splitter 30a3 may be a1 × N optical coupler, where N represents the number of output ends of the optical coupler, and the specific value thereof can be flexibly set according to the number of optical terminals in the optical terminal array. Further, an optical amplifier 30a2 is connected between the output end of the downstream WSS 30a1 and the optical splitter 30a3, and is configured to perform power amplification on the optical signal output by the downstream WSS 30a1, so as to compensate for loss caused by the downstream WSS 30a1, the optical splitter 30a3 and optical connection therebetween, and output the optical signal after power amplification to the optical splitter 30a 3.

Further, as shown in fig. 3a, for the WSS module, the input end of the down WSS 30a1 and the output end of the up WSS 30a4 are connected with optical amplifiers (as shown by the black triangles in fig. 3 a). The optical amplifier connected to the drop WSS 30a1 is configured to perform power amplification on an optical signal received from the optical link, compensate for a line loss caused by the optical link, and transmit the power-amplified optical signal to the drop WSS 30a 1; the optical amplifier connected to the add WSS 30a4 is configured to perform power amplification on the optical signal output by the add WSS 30a4, compensate for the loss caused by the add WSS 30a4 and the optical connection inside the optical path selector, and transmit the power-amplified optical signal to an external WSS module in the ROADM connected to the add WSS 30a 4.

In another alternative embodiment, as shown in fig. 3b, the optical path selector comprises: an optical switch 31 and at least two sets of MUX/DEMUXs 32 connected to the optical switch 31, and each set of MUX/DEMUX is optically connected to one ROADM via an optical link. For wavelength add, the optical switch 31 converts each optical signal received from the optical termination array to a set output port, and combines each optical signal through the MUX connected to the output port, thereby implementing wavelength division multiplexing, and outputs the combined optical signal to the ROADM connected to the optical link. For wavelength drop, first, the DEMUX demultiplexes the group optical signal received from the ROADM connected thereto into a single wavelet, enters the optical switch 31, and the optical switch 31 inputs any wavelet to the output port of the selected optical switch 31 according to the setting and outputs the wavelet to the optical terminal array.

Further, as shown in fig. 3b, for each set of MUX/DEMUXs, an optical amplifier (shown as a triangle in fig. 3 b) is connected to the input of the DEMUX and the output of the MUX. The optical amplifier connected to the DEMUX is configured to perform power amplification on an optical signal received from an optical link, compensate for a line loss caused by the optical link, transmit the optical signal after the power amplification to the DEMUX, and then transmit the optical signal to the optical switch 31; an optical amplifier connected to the MUX is used to power amplify the optical signal output by the MUX, to compensate for other losses in the MUX and the optical path selector, to amplify the optical signal to a desired power level, and then to transmit the amplified signal to the optical link.

Based on the optical network system provided by the embodiment of the application, the sub-network comprising the ROADM can realize Hub function and has cross scheduling capability on optical channels. Furthermore, the optical path selector also has a cross scheduling function for optical channels, and can realize switching of optical links, so that when an optical link between some sub-networks fails, a communication link can be switched to other normal optical links connected with the communication link through the ROADM or the optical path selector in the sub-network corresponding to the failed link, which is beneficial to ensuring normal operation of an optical network system, improving the scheduling capability and the network recovery capability of the optical network, and further improving the performance of the optical network system.

In order to ensure the network restoration capability and the scheduling capability of the optical network system, the optical network provided in the embodiment of the present application further includes: a central control device (not shown in the figures of the above embodiments). The central control device is connected to ROADMs and optical path selectors in sub-networks in the optical network system. Preferably, the central control device is connected to all ROADMs and all optical path selectors in the optical network system. Since the optical network system provided by the embodiment of the application comprises at least one sub-network containing ROADMs, the central control device is connected with at least one ROADM. The central control equipment can be connected with each sub-network through a management network; the management network may be connected by electrical, optical or hybrid optical/electrical connections.

In this embodiment, the central control device is configured to monitor the link status of the link including the optical path selector and the ROADM; and when detecting that a link fails, controlling a target optical path selector or a target ROADM on the original link with the failure to switch from the original link to a non-failure link, and controlling the ROADM on the non-failure link to forward an optical signal from the target optical path selector or the target ROADM. The target optical path selector or target ROADM refers to an optical path selector or ROADM that sends an optical signal on an original link. Wherein an optical link comprising a ROADM and/or comprising an optical path selector comprises the following: an optical link that contains two ROADMs, or refers to an optical link that contains both a ROADM and an optical path selector.

Further, if the optical signal on the original link is sent from the sub-network including the optical path selector, and the optical path selector in the sub-network is the target optical path selector, the central control device may control the target optical path selector on the original link to switch from the original link to the non-faulty link, and in this case, the non-faulty link includes a ROADM, the central control device may further control the ROADM on the non-faulty link to forward the optical signal from the target optical path selector. If the optical signal on the original link is sent out from the sub-network containing the ROADMs, and the ROADMs in the sub-network are the target ROADMs, the central control device may control the target ROADMs to switch from the original link to the non-failed link, in this case, the non-failed link may also include another ROADMs, and the central control device further controls the other ROADMs on the non-failed link to forward the optical signal from the target ROADMs.

The original link with the fault is an original link from the optical signal transmitting end to the optical signal receiving end, the link includes all optical links passing from the optical signal transmitting end to the optical signal receiving end, and at least one of the optical links has the fault. For example, as shown in fig. 1c, assuming that optical signals are transmitted between the sub-network 11a and the sub-network 11c, the original link includes an optical link between the sub-network 11a and the sub-network 11 c. For convenience of description, in the embodiment of the present application, the optical link between two adjacent sub-networks is represented by symbols in combination with the transmission direction of the optical signal, for example, if the optical signal is transmitted from the sub-network 11a to the sub-network 11c, the optical link between the sub-network 11a and the sub-network 11c is simply referred to as a link 11a-11 c; when an optical signal is transmitted from the sub-network 11c to the sub-network 11a, the link therebetween is simply referred to as a link 11c-11 a. For another example, when the optical signal is relayed from the sub-network 11a through the sub-network 11c and transmitted to the sub-network 11e, the link between the three is abbreviated as 11a-11c-11 e; when the optical signal is relayed from the sub-network 11e through the sub-network 11c and transmitted to the sub-network 11a, the link between the three is simply referred to as 11e-11c-11 a.

Correspondingly, a non-failed link refers to another link from the optical signal transmitting end to the optical signal receiving end, where the link includes all optical links passing from the optical signal transmitting end to the optical signal receiving end, and all the optical links are not failed. It is worth noting that non-failed links may overlap with the original link that failed, e.g., may include portions of the optical link that did not fail on the original link. It is worth noting that if an optical signal is emitted by a target ROADM (which also belongs to a non-failed link), the ROADMs on the non-failed link mainly refer to ROADMs other than the ROADM emitting the optical signal. For example, for the original links 11a-11c-11e, where the optical links 11a-11c fail, the optical signals from the sub-network 11a to the sub-network 11e can be transmitted to the sub-network 11e via the non-failed links 11a-11d-11c-11e, where the ROADMs in the sub-network 11d and the sub-network 11c are responsible for forwarding the optical signals from the optical path selectors in the sub-network 11a, and the ROADMs in the sub-network 11c are both on the non-failed links and on the original links.

Optionally, the central control device may further select at least one target link for the target optical path selector or the target ROADM from the plurality of non-failed links when there are a plurality of non-failed links.

Further, the central control device may select at least one target link for the target optical path selector or the target ROADM from the plurality of non-failed links in a variety of ways. For example, the central control device may randomly select one of the plurality of non-failed links as a target link for a target optical path selector or a target ROADM. For another example, the central control device may select, from the plurality of non-failed links, one with the smallest number of link hops for the target optical path selector or the target ROADM as the target link. For another example, the central control device may select, from the plurality of non-failed links, one closest to the target optical path selector or the target ROADM as the target link, or select, from the plurality of non-failed links, one with the largest margin for the target optical path selector or the target ROADM as the target link.

Further, when controlling the target optical path selector or the target ROADM to switch from the original link to the non-failed link, the central control device may send a switching control instruction to the target optical path selector or the target ROADM, where the switching control instruction includes an identifier of the original link and an identifier of the target link, so that the target optical path selector or the target ROADM can switch from the original link to the target link.

Correspondingly, the target optical path selector or the target ROADM receives the switching control instruction, and sends the optical signal carrying the digital signal to the ROADM on the target link according to the identifier of the original link and the identifier of the target link included in the switching control instruction, so as to forward the optical signal through the ROADM on the target link.

Further, when controlling the ROADM on the non-faulty link to forward the optical signal from the target optical path selector or the target ROADM, the central control device also sends a forwarding control instruction to the ROADM on the target link, where the forwarding control instruction includes an identifier of the original link, so that the ROADM on the target link forwards the optical signal from the target optical path selector or the target ROADM on the original link.

Correspondingly, the ROADM on the non-faulty link receives the forwarding control command, and receives and forwards the optical signal from the target optical path selector or the target ROADM on the original link according to the original link in the forwarding control command.

An example is described below in connection with the optical network system shown in fig. 1 c. For the optical network system shown in fig. 1c, assuming that the optical link between the sub-network 11a and the sub-network 11c is failed, and the original link is 11a-11c, the target optical path selector is the optical path selector in the sub-network 11 a. Further, if there are multiple non-failed links, such as links 11a-11d-11c, 11a-11d-11f-11c, 11a-11d-11b-11c, etc., between sub-network 11a and sub-network 11c, the central control device selects link 11a-11d-11c as the target link, so that sub-network 11a can communicate with sub-network 11c via sub-network 11 d. For convenience of description, the original link between the sub-network 11a and the sub-network 11c is denoted as link 1, which is identified as L1; the target link of sub-network 11a to sub-network 11c via sub-network 11d (links 11a-11d-11c) is denoted as link 2, which is identified as L2. The central control device may carry the identifier L1 of the original link and the identifier L2 of the target link in the control switching instruction, and send the control switching instruction to the optical path selector in the sub-network 11 a. The optical path selector in the sub-network 11a receives the control switching instruction, and sends the optical signal carrying the digital signal to the ROADM in the sub-network 11d according to the identifier L1 of the original link (link 1) and the identifier L2 of the target link (link 2), and then the optical signal is forwarded to the sub-network 11c by the ROADM in the sub-network 11 d.

Further, when controlling the ROADM in the sub-network 11d to forward the optical signal from the optical path selector in the sub-network 11a, the central control device also sends a forwarding control instruction to the ROADM in the sub-network 11d, where the forwarding control instruction includes the identifier L1 of the original link (link 1). Accordingly, the ROADM in the sub-network 11d receives the forwarding control command, and receives and forwards the optical signal from the optical path selector in the sub-network 11a according to the identification L1 of the original link (link 1) in the forwarding control command.

For another example, if an optical link between the sub-network 11a and the sub-network 11c is failed and an optical signal is relayed from the sub-network 11e via the sub-network 11c and transmitted to the sub-network 11a, the original link is 11e-11c-11a and the target optical path selector is the optical path selector in the sub-network 11 e. Further, assume that the central control device determines the non-failed link 11e-11c-11d-11a as the target link so that sub-network 11e can communicate with sub-network 11a via sub-networks 11c and 11 d. For convenience of description, the original link 11e-11c-11a is identified as F1; the identification of the target link 11e-11c-11d-11a is denoted as F2. The central control device may carry the identification F1 of the original link and the identification F2 of the target link in the control handover command and send the control handover command to the ROADM in the sub-network 11 c. The ROADM in the sub-network 11c receives the control switching instruction, and sends the optical signal carrying the digital signal to the ROADM in the sub-network 11d according to the identifier F1 of the original link and the identifier F2 of the target link, and then the ROADM in the sub-network 11d forwards the optical signal to the sub-network 11 a.

Further, when controlling the ROADMs in the sub-network 11c and the sub-network 11d to forward the optical signal from the optical path selector in the sub-network 11e, the central control device also sends a forwarding control instruction to the ROADM in the sub-network 11d, where the forwarding control instruction includes the identifier F1 of the original link. Accordingly, the ROADM in the sub-network 11d receives the above-mentioned forwarding control command, and receives and forwards the optical signal transmitted from the ROADM in the sub-network 11c, based on the identification F1 of the original link in the forwarding control command. The optical signals of ROADMs in the sub-network 11c are sent from the optical path selector in the sub-network 11 e.

It should be noted that the optical network system provided by the above embodiments is applicable to various network application scenarios, for example, may be applied to a local area network, a metropolitan area network, or even a larger-scale network scenario. Also, for example, it is applicable to an interconnection network between Data Centers (DC), and particularly to an optical interconnection network between Data centers of a metropolitan area network. The following takes a data center interconnection network as an example for illustrative explanation.

The data center interconnection network includes a plurality of DCs; at least one of the plurality of DCs includes a ROADM, and at least one of the DCs other than the DC including the ROADM includes an optical path selector. Optionally, other DCs that do not include either a ROADM or an optical path selector, i.e., a DC that includes a conventional connector without optical path selection capability, may also be included in the data center interconnection network.

In this embodiment, multiple DCs may be optically connected through ROADMs and optical path selectors. Each DC containing the optical path selector can be optically connected with the ROADM in the DC containing the ROADM through the optical path selector contained in the DC. Alternatively, if there is also a DC containing a legacy connector in the data center interconnection network, the DC containing the legacy connector may be optically connected to a ROADM in the DC containing the ROADM through the legacy connector it contains. Of course, the DC including the conventional connector may also be optically connected to the DC including the optical path selector through the conventional connector included in the DC, and the optical connection between the DCs may be determined according to the interconnection requirement of the data center, which is not limited in this embodiment. Therefore, the optical connection between the DCs can be realized through the ROADM without adopting a straight-through optical link for optical connection, the number of the optical links can be reduced, the interconnection structure between data centers can be simplified, and the interconnection cost between the data centers can be reduced.

When an optical link between DCs interconnected through a ROADM and an optical path selector fails, a communication link can be switched to other normal optical links through the ROADM or the optical path selector corresponding to the failed link, so that the normal operation of the data center interconnection network is guaranteed, the scheduling capability and the network recovery capability of the data center interconnection network are improved, and the communication performance of the data center interconnection network is further improved.

The number of optical links of the data center interconnection network is further reduced, and the scheduling capability and the network recovery capability of the data center interconnection network are improved. The number of DCs comprising a ROADM in the data center interconnection network may be at least 2; and other DCs besides ROADMs include optical path selectors. Such an optical network system is exemplified below.

Fig. 4 is a schematic structural diagram of a data center interconnection network according to an embodiment of the present application. As shown in fig. 4, the interconnection network includes a plurality of DCs. Of the plurality of DCs, at least 2 DCs include ROADMs, and DCs other than the ROADMs include optical path selectors. In fig. 4, the number of DC is merely 6, but the number is not limited thereto. Further, in fig. 4, DC3 and DC4 are DC including ROADM, and DC1, DC2, DC5, and DC6 are DC including optical path selectors. In fig. 4, only 2 DCs including ROADMs and 4 DCs including optical path selectors are illustrated, but not limited thereto.

In this embodiment, connection is made between every two ROADMs and between each optical path selector and each ROADM through an optical link. For example, in the network shown in fig. 4, the optical path selectors in DC1, DC2, DC5, and DC6 are all connected to ROADMs in DC3 and DC4 via optical links.

In this embodiment, the data center interconnection network includes a plurality of DCs, wherein at least two DCs include ROADMs, the other DCs include optical path selectors, and optical connections are made between the DCs through the ROADMs of the at least two DCs and the optical path selectors of the other DCs. Therefore, the DCs including the optical path selector can be connected through the ROADM, and the connection among the DCs in the data center interconnection network can be realized without adopting a direct optical link connection, so that the number of optical links is reduced, the connection structure of an optical network system is simplified, and the network cost is reduced.

Further, in this embodiment, the DC including the ROADM can implement the Hub function, and has the cross-scheduling capability for the optical channels. Furthermore, the optical path selector has the switching function of the optical link, and is matched with the Hub function of the ROADM, when the optical link between some DCs fails, the communication link can be switched to other normal optical links through the ROADM or the optical path selector corresponding to the failed link, so that the normal operation of the data center interconnection network is favorably ensured, the scheduling capability and the network recovery capability of the data center interconnection network are improved, and the communication performance of the data center interconnection network is further improved. For example, as shown in fig. 4, if the optical link between DC1 and DC3 fails, communication between DC1 and DC3 may be switched to communication between DC1 and DC3 via DC4 relay, and so on. For a specific implementation of performing optical link switching when an optical link between the DCs fails, reference will be made to relevant contents in the foregoing embodiments, and details will not be described here.

Further, in this embodiment, the DC of the data center interconnection network is not constructed by using ROADMs, but is partially constructed by using ROADMs, and partially constructed by using relatively low-priced optical path selectors, so that the network cost can be further reduced.

It is worth noting that in the present embodiment, the ROADM may adopt various types of ROADMs. For example, wavelength-dependent and direction-dependent ROADMs, wavelength-independent and direction-dependent ROADMs, wavelength-dependent and direction-independent ROADMs, CD-ROADMs, CDC-ROADMs, or the like may be employed. Preferably, a CD-ROADM or a CDC-ROADM may be used, which may improve the flexibility of optical channel scheduling in the optical network system. For the implementation form of the CD-ROADM, reference may be made to the description of relevant contents in fig. 2 in the above embodiment, and details are not described here again.

Further, the optical path selector may be implemented by a WSS module or an optical switch. For two implementation manners of the optical path selector using the WSS module or the optical switch, reference may be made to relevant contents in fig. 3a and fig. 3b in the foregoing embodiment, and details are not repeated here.

Based on the optical network system provided in the above embodiment, the embodiment of the present application further provides a scheduling method of the optical network system. This is exemplified below from the perspective of a central control device.

Fig. 5 is a flowchart illustrating a scheduling method of an optical network system according to an embodiment of the present application. The method is suitable for the central control equipment. As shown in fig. 5, the method includes:

501. link states of optical links including ROADMs and/or including optical path selectors in the optical network system are monitored.

502. When a link failure is detected, controlling a target optical path selector or a target ROADM on a failed original link to switch from the original link to a non-failed link, and controlling the ROADM on the non-failed link to forward an optical signal from the target optical path selector or the target ROADM.

In this embodiment, an optical link comprising a ROADM and/or comprising an optical path selector comprises the following cases: an optical link that contains two ROADMs, or refers to an optical link that contains both a ROADM and an optical path selector.

In this embodiment, the target optical path selector or target ROADM refers to an optical path selector or ROADM that sends out optical signals on the original link. Further, if the optical signal on the original link is sent from the sub-network including the optical path selector, and the optical path selector in the sub-network is the target optical path selector, the central control device may control the target optical path selector on the original link to switch from the original link to the non-faulty link, and in this case, the non-faulty link includes a ROADM, the central control device may further control the ROADM on the non-faulty link to forward the optical signal from the target optical path selector on the original link. If the optical signal on the original link is sent out from the sub-network containing the ROADMs, and the ROADMs in the sub-network are the target ROADMs, the central control device may control the target ROADMs to switch from the original link to the non-failed link, in this case, the non-failed link may also include another ROADMs, and the central control device further controls the other ROADMs on the non-failed link to forward the optical signal from the target ROADMs. For the descriptions of the failed link, the non-failed link, and the ROADM on the non-failed link, reference may be made to the relevant contents of the above embodiments, which are not described herein again.

In addition, for the implementation form of the optical network system, reference may be made to relevant contents in the embodiment shown in fig. 1b, and details are not described herein again.

In this embodiment, the sub-network including ROADM can implement Hub function, and has cross-scheduling capability for optical channels. Furthermore, the optical path selector has a switching function of an optical link, and is matched with a Hub function of a ROADM (reconfigurable optical Add drop multiplexer), when the optical link between some sub-networks fails, the communication link can be switched to other normal optical links through the optical path selector corresponding to the failed link, so that the normal operation of an optical network system is guaranteed, the scheduling capability and the network recovery capability of the optical network are improved, and the communication performance of the optical network system is further improved.

Optionally, when there are multiple non-failed links, at least one target link may also be selected for the target optical path selector or the target ROADM from the multiple non-failed links before step 502.

Further, the at least one target link may be selected for the target optical path selector or the target ROADM from the plurality of non-failed links in a variety of ways. For example, one of the multiple non-failed links may be randomly selected as a target link for a target optical path selector or a target ROADM. For another example, one of the plurality of non-failed links with the smallest number of link hops may be selected as the target link for the target optical path selector or the target ROADM. For another example, a closest link to the target optical path selector or the target ROADM may be selected as the target link from the plurality of non-failed links, or a maximum margin link may be selected as the target link for the target optical path selector or the target ROADM from the plurality of non-failed links.

Further, in step 502, when controlling the target optical path selector or the target ROADM on the original link to switch from the original link to at least one target link, a switching control instruction may be sent to the target optical path selector or the target ROADM, where the switching control instruction includes an identifier of the original link and an identifier of the target link, so that the target optical path selector or the target ROADM can switch from the original link to the target link.

Optionally, when controlling the ROADM on the non-failed link to forward the optical signal from the target optical path selector or the target ROADM, a forwarding control instruction may be sent to the ROADM on the target link, where the forwarding control instruction includes an identifier of the original link, so that the ROADM on the target link forwards the optical signal from the target optical path selector or the target ROADM on the original link.

Correspondingly, the ROADM on the non-faulty link receives the forwarding control command, and receives and forwards the optical signal from the target optical path selector or the target ROADM on the original link according to the identifier of the original link in the forwarding control command.

It should be noted that the execution subjects of the steps of the methods provided in the above embodiments may be the same device, or different devices may be used as the execution subjects of the methods. For example, the execution subjects of step 501 and step 502 may be device a; for another example, the execution subject of step 501 may be device a, and the execution subject of step 502 may be device B; and so on.

In addition, in some of the flows described in the above embodiments and the drawings, a plurality of operations are included in a specific order, but it should be clearly understood that the operations may be executed out of the order presented herein or in parallel, and the sequence numbers of the operations, such as 501, 502, etc., are merely used for distinguishing different operations, and the sequence numbers themselves do not represent any execution order. Additionally, the flows may include more or fewer operations, and the operations may be performed sequentially or in parallel. It should be noted that, the descriptions of "first", "second", etc. in this document are used for distinguishing different messages, devices, modules, etc., and do not represent a sequential order, nor limit the types of "first" and "second" to be different.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An optical network system, comprising: a plurality of sub-networks; wherein, at least one sub-network in the plurality of sub-networks comprises a reconfigurable optical add-drop multiplexer ROADM, and at least one sub-network in other sub-networks except the ROADM sub-network comprises an optical path selector; and the plurality of sub-networks are optically connected with the optical path selector through the ROADM.

2. The method of claim 1, wherein the plurality of subnetworks include at least two ROADMs, and the subnetworks other than the ROADM-containing subnetwork include optical path selectors.

3. The optical network system of claim 2, wherein each two ROADMs and each optical path selector and each ROADM are connected by an optical link.

4. The optical network system of claim 2, wherein the ROADMs employ direction-independent wavelength-independent CD-ROADMs or direction-independent, wavelength-independent, and contention-independent CDC-ROADMs.

5. The optical network system of claim 4, wherein the CD-ROADM comprises: the system comprises a local WSS module and at least one external WSS module; the local WSS module is optically connected with each external WSS module and each two external WSS modules, and each external WSS module is also optically connected with an external WSS module in an optical path selector or another ROADM through an optical link.

6. The optical network system of claim 5, wherein the local WSS module or each external WSS module comprises an add WSS and a drop WSS; the upper WSS and the lower WSS of the local WSS module are respectively and correspondingly optically connected with the upper WSS and the lower WSS of each external WSS module; between each two external WSS modules, an upper WSS in one WSS module is optically connected with a lower WSS in the other WSS module; the add WSS and drop WSS in each external WSS module are optically connected to an optical path selector in another subnetwork or an external WSS module in a ROADM via optical links.

7. The optical network system according to claim 5, wherein in the local WSS module, an input end of an add WSS is connected with an optical combiner, and an output end of a drop WSS is connected with an optical splitter.

8. The optical network system of claim 2, wherein the optical path selector comprises a WSS module, and wherein the WSS module is connected to one ROADM via an optical link.

9. The optical network system of claim 8, wherein the WSS module comprises an add WSS and a drop WSS; each output port of the add WSS is connected with one ROADM through an optical link, and each input port of the drop WSS is connected with one ROADM through an optical link.

10. The optical network system according to claim 8, wherein in the WSS module, an input end of the upper WSS is connected to an optical combiner, and an output end of the lower WSS is connected to an optical splitter.

11. The optical network system of claim 1, wherein the optical path selector comprises an optical switch, and at least two sets of multiplexer MUX/demultiplexer DEMUX coupled to the optical switch, each set of MUX/DEMUX coupled to one ROADM via an optical link.

12. The optical network system of claim 1, wherein the other sub-networks comprise: at least one sub-network comprising a light path selector, and at least one sub-network comprising a legacy connector without light path selection capability; the optical path selector and the legacy connector are both optically connected to the ROADM.

13. The optical network system according to any of claims 1-12, further comprising: a central control device; the central control equipment is connected with a ROADM and an optical path selector in the optical network system;

the central control device is used for monitoring the link state of an optical link comprising an optical path selector and/or a ROADM; and when detecting that a link fails, controlling a target optical path selector or a target ROADM on a failed original link to switch from the original link to a non-failed link, and controlling the ROADM on the non-failed link to forward an optical signal from the target optical path selector or the target ROADM.

14. The optical network system of claim 13, wherein the central control apparatus is further configured to: and when a plurality of non-fault links exist, selecting at least one target link from the plurality of non-fault links for the target optical path selector or the target ROADM.

15. The optical network system according to claim 14, wherein the central control device is specifically configured to perform at least one of the following operations:

randomly selecting one of the target optical path selector or the target ROADM as a target link from the plurality of non-fault links;

selecting one link with the least hop number as a target link from the plurality of non-fault links for the target optical path selector or the target ROADM;

selecting one of the plurality of non-failed links that is closest to the target optical path selector or the target ROADM as a target link;

and selecting one of the plurality of non-faulty links with the largest margin as a target link for the target optical path selector or the target ROADM.

16. The optical network system of claim 14,

when the central control device controls the target optical path selector or the target ROADM to switch from the original link to the non-failed link, the central control device is specifically configured to: sending a switching control instruction to the target optical path selector or the target ROADM, wherein the switching control instruction comprises an identifier of an original link and an identifier of a target link, so that the target optical path selector or the target ROADM can be switched from the original link to the target link;

the target optical-path selector or the target ROADM is further configured to: and receiving the switching control instruction, and sending the optical signal carrying the digital signal to the ROADM on the target link according to the identifier of the original link and the identifier of the target link contained in the switching control instruction so as to forward the optical signal through the ROADM on the target link.

17. The optical network system of claim 14,

when the central control device controls the ROADM on the non-faulty link to forward the optical signal from the target optical path selector or the target ROADM, the central control device is specifically configured to: sending a forwarding control instruction to the ROADM on the target link, wherein the forwarding control instruction comprises an identifier of an original link, so that the ROADM on the target link forwards an optical signal from a target optical path selector or the target ROADM on the original link;

the ROADM on the non-failed link is further to: and receiving the forwarding control instruction, receiving an optical signal from a target optical path selector on the original link or the target ROADM according to the identification of the original link in the forwarding control instruction, and forwarding the optical signal.

18. A data center interconnection network, comprising a plurality of data center DCs; at least two DCs in the plurality of DCs comprise reconfigurable optical add-drop multiplexers (ROADMs), and other DCs except the at least two DCs comprise optical path selectors; and each two ROADMs and each optical path selector and each ROADM are connected through optical links.

19. The network of claim 18, wherein the ROADMs employ direction-independent, wavelength-independent CD-ROADMs or direction-independent, wavelength-independent, and contention-independent CDC-ROADMs.

20. A network according to claim 18 or 19, wherein the optical path selector uses WSS or optical switches.

21. A method for scheduling an optical network system, comprising:

22. The method of claim 21, wherein controlling the target optical path selector or the target ROADM on the failed link to switch from the original link to a non-failed link comprises:

when a plurality of non-fault links exist, selecting at least one target link for the target light path selector from the plurality of non-fault links;

and controlling a target optical path selector or the target ROADM on the original link to be switched from the original link to the at least one target link.

23. The method of claim 22, wherein selecting at least one target link for the target optical path selector or the target ROADM from the plurality of non-failed links comprises at least one of:

24. The method of claim 22 or 23, wherein controlling a target optical path selector or a target ROADM on the original link to switch from the original link to the at least one target link comprises:

and sending a switching control instruction to the target optical path selector or the target ROADM, wherein the switching control instruction comprises an original link and a target link, so that the target optical path selector or the target ROADM can be switched to the target link from the original link.

25. The method of claim 22 or 23, wherein controlling the ROADM on the non-failed link to forward the optical signal from the target optical path selector or the target ROADM comprises:

and sending a forwarding control instruction to the ROADM on the target link, wherein the forwarding control instruction comprises an original link, so that the ROADM on the target link forwards an optical signal from a target optical path selector or the target ROADM on the original link.