Large-scale OTN (Optical Transport Network) routing calculation method and device

Abstract

The invention provides a large-scale OTN network routing calculation method and device, and the method comprises the steps: generating an optical channel label according to each first potential optical channel, and putting the optical channel labels into a first queue; one optical channel label with the minimum total cost is taken out from the first queue to serve as a first label; if the destination node and other optical channel labels which are consistent with the first label in wavelength and are taken out do not exist, constructing a target path; if the destination node of the first label is not the destination node of the service and the target path is successfully constructed, generating an optical channel label according to each second potential optical channel, and putting the optical channel label into a first queue; if the destination node of the first label is not the destination node of the service and the first queue is not empty, taking out a new first label again; and if the destination node of the first label is the destination node of the service and the target path is successfully constructed, connecting the first label with the target paths corresponding to all the forward labels to obtain an optimal path of the service. According to the method and the device, the large-scale OTN network routing calculation efficiency is remarkably improved.

Description

Technical Field

[0001] The present application relates to the technical field of OTN routing calculation, and in particular to a large-scale OTN network routing calculation method and device. Background Art

[0002] In the field of optical transmission networks, with the rapid development of communications technology, network scale continues to expand, and service demands are becoming increasingly complex and diverse. In the initial stages of network construction, operator customers provide the network's node and link layout, along with a service planning matrix. Design institutes and other organizations then use this information to allocate path resources across the entire network. The service planning matrix only specifies the source and destination nodes and optical channel types, such as 100G, 200G, or 400G. Planning requires determining end-to-end paths, wavelengths, trunks, line ports, and other resources. For ultra-large-scale networks (over 1,000 nodes and 3,000 links), rapid service planning has become a key trend in optical network planning. Furthermore, as OTN networks continue to expand in size, efficient algorithms are urgently needed to support fault recovery and capacity expansion in existing networks.

[0003] In existing technologies, integer linear programming modeling can solve the multi-objective optimization problem of optical transmission network service planning for small-scale or small-batch service networks, but its efficiency is extremely low in large-scale network scenarios. Currently, the best approach for handling large-scale networks is to split the problem into three sub-problems: using the K-Shortest Path Algorithm to calculate K paths, sequentially assigning relays to these K paths, and then allocating channels to the paths with assigned relays. However, due to the limitations of the Dijkstra algorithm, its search space is shaped like a gradually expanding circle. A path can only be found when the radius of the circle is expanded to include the source and destination nodes. Consequently, in large-scale networks, K must be set to a maximum value to calculate all services, severely impacting computational efficiency and the timeliness of resource allocation. Therefore, a new, fast algorithm is urgently needed to meet the needs of large-scale optical transmission network service planning. Summary of the Invention

[0004] The present application provides a large-scale OTN network routing calculation method and device, which can solve the technical problem of low efficiency of large-scale OTN network routing calculation in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a large-scale OTN network routing calculation method, the large-scale OTN network routing calculation method comprising: Generate an optical channel label for each first potential optical channel and place it in the first queue, where the source node of the first potential optical channel is the source node of the service, and the fields of the optical channel label include the previous label, source node, sink node, wavelength, total cost, and OSNR threshold, where the total cost is the sum of the actual cost of the established path and the estimated cost of the unestablished path; Taking an optical channel label with the smallest total cost from the first queue as the first label; If there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, construct a target path, where the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label; If the sink node of the first label is not the sink node of the service and the target path is successfully established, the first label is used as the previous label, and an optical channel label is generated according to each second potential optical channel, and the optical channel label is placed in the first queue, wherein the source node of the second potential optical channel is the sink node of the first label, and the sink node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels; If the sink node of the first label is not the sink node of the service and the first queue is not empty, a new first label is retrieved; If the destination node of the first label is the destination node of the service and the target path is successfully constructed, the target paths corresponding to the first label and all its forward labels are connected to obtain the optimal path for the service.

[0006] Furthermore, in one embodiment, the step of constructing the target path includes: Constructing an optical link label according to the first available link and placing the label into the second queue, wherein requirements for the available link include: the sink node does not appear in the target paths corresponding to all forward labels of the first label, the wavelength of the first label is not occupied, the source node of the first available link is the source node of the first label, and the fields of the optical link label include the previous label, the sink node, and the total cost; Taking an optical link label with the minimum total cost from the second queue as the second label; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label with the same destination node as the second label that has been extracted, then use the second label as the previous label, construct an optical link label according to each second available link, and put it into the second queue, wherein the source node of the second available link is the destination node of the second label; If the destination node of the second label is not the destination node of the first label, and the second queue is not empty, a new second label is retrieved; If the sink node of the second label is the sink node of the first label, then the links corresponding to the second label and all its forward labels are connected to obtain the optimal optical channel path; If the equivalent OSNR value of the optimal optical channel path is less than the OSNR threshold of the first label, the optimal optical channel path is determined as the target path.

[0007] Furthermore, in one embodiment, the requirement for an available link also includes: there is no optical link label that has the same sink node and has been removed.

[0008] Furthermore, in one embodiment, the field of the optical link label also includes an equivalent OSNR value of the constructed path; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the equivalent OSNR value of the constructed path of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0009] Furthermore, in one embodiment, the field of the optical link label further includes a total OSNR value, where the total OSNR value is the sum of the equivalent OSNR value of the constructed path and the estimated OSNR value of the unconstructed path; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the total OSNR value of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0010] Furthermore, in one embodiment, there is no optical channel label whose sink node and wavelength are consistent with the second potential optical channel and has been removed.

[0011] Furthermore, in one embodiment, the cost types involved in the optical channel label include wavelength cost, local group cost, relay cost, and link length cost.

[0012] Furthermore, in one embodiment, before the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, and actual relay cost of the label and all its forward labels, the actual link length cost of all forward labels, the estimated link length cost of the label, and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the sink node of the label to the sink node of the service; After the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, actual relay cost, and actual link length cost of the label and all its forward labels, as well as the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the label's sink node to the service's sink node.

[0013] Furthermore, in one embodiment, before the step of generating an optical channel label according to each first potential optical channel and placing the optical channel label into the first queue, the step further includes: Calculate the minimum link length between every two nodes using Dijkstra algorithm; If the minimum link length between any two nodes is less than a preset length threshold, it is determined that there is a potential optical channel between the two nodes, where the wavelength of the potential optical channel is a wavelength that can be emitted by the source node and received by the sink node.

[0014] In a second aspect, an embodiment of the present application further provides a large-scale OTN network routing calculation device, the large-scale OTN network routing calculation device comprising: an initialization module, configured to generate an optical channel label according to each first potential optical channel and place the label into a first queue, wherein the source node of the first potential optical channel is the source node of the service, and the fields of the optical channel label include a previous label, a source node, a sink node, a wavelength, a total cost, and an OSNR threshold, where the total cost is the sum of an actual cost of a constructed path and an estimated cost of an unconstructed path; a label extraction module, configured to extract an optical channel label with the minimum total cost from the first queue as a first label; a path construction module, configured to construct a target path if there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, wherein the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label; a label extension module configured to, if the sink node of the first label is not the sink node of the service and the target path is successfully established, use the first label as the previous label, generate an optical channel label according to each second potential optical channel, and place the optical channel label in the first queue, wherein the source node of the second potential optical channel is the sink node of the first label, and the sink node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels; A callback module, configured to retrieve a new first label if the destination node of the first label is not the destination node of the service and the first queue is not empty; The result output module is configured to connect the target paths corresponding to the first label and all its forward labels to obtain the optimal path for the service if the destination node of the first label is the destination node of the service and the target path is successfully constructed.

[0015] In this application, the path search algorithm is executed in two layers. The first-layer search algorithm uses the potential optical channel as a whole to expand the path. Through the management mechanism of the optical channel label and the first queue, the optical channel is extended from the source node of the service to the destination node of the service. In the extended path, different optical channels of the same wavelength will not intersect, and a single path will not form a loop. Only the optimal label taken from the first queue will trigger the second-layer search algorithm. The second layer will concretize the node link through which the potential optical channel passes and determine whether the OSNR threshold requirement is met. Through this application, the disadvantage of the Dijkstra algorithm of blindly expanding the search space is avoided, the time cost of searching the path is greatly reduced, and the efficiency of the algorithm is significantly improved. It is particularly suitable for ultra-large-scale network service planning. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is a flow chart of a large-scale OTN network routing calculation method according to an embodiment of the present application; Figure 2 A schematic diagram of the physical topology in one embodiment of the present application; Figure 3 for Figure 2 Schematic diagram of potential optical channels corresponding to the physical topology in the illustrated embodiment; Figure 4 Schematic diagram of the functional modules of a large-scale OTN network routing calculation device in one embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] First, some technical terms in this application are explained to facilitate those skilled in the art to understand this application.

[0018] Node: The node in this application is an optical add / drop multiplexing node, including a local group and a relay.

[0019] Local group: an optical add / drop multiplexing device used to combine and split optical signals.

[0020] Relay: The starting point of the optical channel. Generally speaking, the relay is more expensive and is the device that needs to control costs the most.

[0021] Link: The link in this application is an optical fiber link, which is a physical path connecting two nodes. Its model, length, and equivalent OSNR (Optical Signal-to-Noise Ratio) value are known.

[0022] Optical channel: A logical path used to transmit optical signals in an optical network, passing through a series of optical fiber links. Each optical channel has a consistent wavelength and the equivalent OSNR value of the optical fiber links is less than the equivalent OSNR threshold for light to pass through.

[0023] Service: A connection request from a source node to a destination node.

[0024] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0025] In a first aspect, an embodiment of the present application provides a large-scale OTN network routing calculation method.

[0026] Figure 1 A schematic diagram of a process for calculating large-scale OTN network routing in an embodiment of the present application is shown.

[0027] Reference Figure 1 In one embodiment, a large-scale OTN network routing calculation method includes the following steps: S1. Generate an optical channel label for each first potential optical channel and place it in a first queue. The source node of the first potential optical channel is the source node of the service. The fields of the optical channel label include the previous label, source node, sink node, wavelength, total cost, and OSNR threshold. The total cost is the sum of the actual cost of the constructed path and the estimated cost of the unconstructed path.

[0028] Specifically, the definition of a potential optical channel is as follows: if it is estimated that the optical signal of a preset wavelength emitted by the first node can be received by the second node without using a relay, then it is considered that a potential optical channel exists, and its source node, destination node and wavelength are the first node, the second node and the preset wavelength respectively.

[0029] It should be noted that in actual situations, whether a relay is needed is determined by whether the equivalent OSNR value is less than the corresponding OSNR threshold. When determining the potential optical channel, a simpler method can be used to estimate the optical propagation between two nodes to reduce the amount of calculation.

[0030] The total cost of an optical channel label is the sum of the actual cost of the established path between the source and sink nodes for that label and all its forward labels (previous label, previous label, and so on), and the estimated cost of the unestablished path. For the same path, the estimated cost is less than the actual cost and as close as possible to the actual cost, ensuring the accuracy and speed of the algorithm.

[0031] Optionally, the cost calculation method and the cost types considered can be set as needed. For example, wavelength cost, local group cost, relay cost, and link length cost are usually considered in OTN network routing calculation.

[0032] Figure 2 A schematic diagram showing a physical topology in an embodiment of the present application is shown. Figure 3 Shown Figure 2 Schematic diagram of potential optical channels corresponding to the physical topology in the illustrated embodiment.

[0033] Reference Figure 2 and Figure 3 Example A1: Node 1 is the source node of the service. Only one wavelength is considered. The potential optical channels and optical channel labels are simplified as source node number-destination node number. The first potential optical channels are 1-2, 1-3, and 1-6, generating three optical channel labels.

[0034] S2. Take an optical channel label with the smallest total cost from the first queue as the first label.

[0035] Optionally, the first queue and the second queue described later may adopt one of a Fibonacci heap, a max-max heap, a min-max heap or a binomial heap.

[0036] Optionally, when there is more than one smallest optical channel label in the first queue, the optical channel label with the smallest wavelength sequence number is selected as the first label.

[0037] S3. If there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, construct a target path, where the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label.

[0038] Specifically, the premise for constructing the target path is that there is no other optical channel label whose sink node and wavelength are consistent with the first label and have been removed, thereby ensuring that different optical channels with the same wavelength will not cross in the extended path.

[0039] When constructing the target path, the system first constructs an optimal path that meets the source node, destination node, and wavelength requirements of the first label. It then determines whether this path meets the OSNR threshold required by the first label. Only optical channel labels removed from the first queue are used to construct the actual node link, significantly reducing the computational effort required to build the node link. The OSNR threshold ensures that the potential optical channel estimates are correct, and thus the total cost of the optical channel label is accurate and reliable.

[0040] Since the optical channel label is established based on the potential optical channel, the span between the two nodes will not be too large, which is equivalent to a small-scale business request. The path construction method can refer to the solutions in related technologies. Optional implementation methods will also be provided later, so I will not go into details here.

[0041] Reference Figure 2 and Figure 3 Example A2: Continuing the settings of Example A1, the optical channel label taken out for the first time is 1-6, and the target path constructed is "node 1-3-6".

[0042] S4. If the destination node of the first label is not the destination node of the service and the target path is successfully established, the first label is used as the previous label, and an optical channel label is generated according to each second potential optical channel, and is placed in the first queue, wherein the source node of the second potential optical channel is the destination node of the first label, and the destination node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels.

[0043] Specifically, if the destination node of the first label is not the destination node of the service, it means that the service path has not yet been established. If the target path is successfully established, it means that the path is worth further expansion. The path is expanded by adding an optical channel label generated based on the second potential optical channel to the first queue. The newly added label is removed and the target path is successfully established, completing the path expansion.

[0044] Specifically, the sink node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels, thereby ensuring that the single path does not form a loop.

[0045] Reference Figure 2 and Figure 3 Example A3: Continuing the settings of Example A2, the potential optical channels with node 6 as the source node are 6-1, 6-2, 6-3, 6-4, and 6-7. Nodes 1 and 3 appear in the target path "node 1-3-6" corresponding to the optical channel label 1-6. Therefore, the second potential optical channels corresponding to the optical channel label 1-6 are 6-2, 6-4, and 6-7, generating three optical channel labels.

[0046] S5. If the destination node of the first label is not the destination node of the service and the first queue is not empty, a new first label is retrieved.

[0047] Correspondingly, if the sink node of the first label is not the sink node of the service and the first queue is empty, it is determined that the construction of the optimal path for the service has failed.

[0048] S6. If the destination node of the first label is the destination node of the service and the target path is successfully constructed, connect the target paths corresponding to the first label and all its forward labels to obtain an optimal path for the service.

[0049] Optionally, after calculating the optimal service path, the total cost of the optimal service path may be further verified to determine whether to use the path in the end.

[0050] Therefore, in this embodiment, the path search algorithm is executed in two layers. The first layer performs path expansion based on potential optical channels as a whole. Through the management mechanism of optical channel labels and the first queue, the optical channel is extended from the service source node to the service destination node. In the extended path, different optical channels with the same wavelength do not intersect, and a single path does not form a loop. Only the optimal label extracted from the first queue triggers the second layer of the search algorithm. The second layer specifies the node links through which the potential optical channel passes and determines whether they meet the OSNR threshold requirements. This embodiment avoids the drawback of the Dijkstra algorithm of blindly expanding the search space, significantly reduces the time cost of path search, and significantly improves the algorithm efficiency. It is particularly suitable for ultra-large-scale network service planning.

[0051] Furthermore, in one embodiment, there is no optical channel label whose sink node and wavelength are consistent with the second potential optical channel and has been removed.

[0052] In this embodiment, if there is an optical channel label whose sink node and wavelength match those of a potential optical channel and has already been extracted, then the optical channel label generated based on the potential optical channel cannot be used for path construction and path extension even after it is placed in the first queue and then removed, resulting in unnecessary computation and time consumption. Therefore, a restriction condition for the second potential optical channel is added to further reduce the computation and improve routing calculation efficiency.

[0053] Figure 4 Shown Figure 3 Schematic diagram of optical channel label generation in the illustrated embodiment.

[0054] Reference Figure 3 and Figure 4 Example A4: Continuing with the settings of Example A3, the second optical channel label extracted is 1-2, and the target path constructed is node 1-2. The potential optical channels with node 2 as the source node are 2-1, 2-4, 2-5, and 2-6. Node 1 appears in the target path "node 1-2" corresponding to optical channel label 1-2. Node 6 is the sink node of the extracted optical channel label 1-6. Therefore, the second potential optical channels corresponding to optical channel label 1-2 are 2-4 and 2-5, generating two optical channel labels.

[0055] Furthermore, in one embodiment, the cost types involved in the optical channel label include wavelength cost, local group cost, relay cost, and link length cost.

[0056] In this embodiment, wavelength cost, local group cost, relay cost and link length cost are comprehensively considered, and the optimal solution to the multi-objective optimization problem can be obtained by adjusting the weights of various types of costs when superimposed.

[0057] For example, the cost of adding relays to each node is set to 1e8, the cost of the local group on the node is set to 1e8, the coefficient of the link wavelength is 1000, the first wave is 0, and each subsequent wave is the cube of the wavelength number. For example, the cost of using the channel numbered 10 is 1000*10*10*10=1e6.

[0058] Specifically, before the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, and actual relay cost of the label and all its forward labels, the actual link length cost of all forward labels, the estimated link length cost of the label, and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the sink node of the label to the sink node of the service; After the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, actual relay cost, and actual link length cost of the label and all its forward labels, as well as the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the label's sink node to the service's sink node.

[0059] Furthermore, in one embodiment, the field of the optical channel label also includes an actual forward cost. Before the target path corresponding to an optical channel label is constructed, the actual forward cost of the label is the sum of the actual forward cost of the previous label and the actual wavelength cost, actual local group cost, and actual relay cost of the label. The total cost of the label is the sum of the actual forward cost of the label, the estimated link length cost of the label, and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the sink node of the label to the sink node of the service. After the target path corresponding to an optical channel label is constructed, the actual forward cost of the label is the sum of the actual forward cost of the previous label and the actual wavelength cost, actual local group cost, actual relay cost, and actual link length cost of the label. The total cost of the label is the sum of the actual forward cost of the label and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the destination node of the label to the destination node of the service.

[0060] In this embodiment, by adding a field for the actual forward cost in the optical channel label, the actual forward cost of each optical channel label can be calculated by the actual forward cost of the previous label and the actual cost newly added to the label. There is no need to find all forward labels for calculation, which facilitates the rapid calculation of the actual forward cost, and then the total cost is quickly calculated by superimposing the estimated cost on the basis of the actual forward cost.

[0061] Furthermore, in one embodiment, before the step of generating an optical channel label according to each first potential optical channel and placing the optical channel label into the first queue, the step further includes: Calculate the minimum link length between every two nodes using Dijkstra algorithm; If the minimum link length between any two nodes is less than a preset length threshold, it is determined that there is a potential optical channel between the two nodes, where the wavelength of the potential optical channel is a wavelength that can be emitted by the source node and received by the sink node.

[0062] In this embodiment, when determining potential optical channels, a threshold is determined based on the link length. The link length is positively correlated with the equivalent OSNR value, which facilitates rapid identification of potential optical channels while ensuring a certain degree of accuracy.

[0063] For example, the minimum link length between node A and node B is less than a preset length threshold, and both node A and node B can emit and receive wavelengths 1, 2, and 3. Then there are three potential optical channels with node A as the source node, node B as the sink node, and wavelengths 1, 2, and 3, respectively, and three potential optical channels with node B as the source node, node A as the sink node, and wavelengths 1, 2, and 3, respectively, for a total of six potential optical channels.

[0064] Furthermore, in one embodiment, the step of constructing the target path includes: Constructing an optical link label according to the first available link and placing the label into the second queue, wherein requirements for the available link include: the sink node does not appear in the target paths corresponding to all forward labels of the first label, the wavelength of the first label is not occupied, the source node of the first available link is the source node of the first label, and the fields of the optical link label include the previous label, the sink node, and the total cost; Taking an optical link label with the minimum total cost from the second queue as the second label; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label with the same destination node as the second label that has been extracted, then use the second label as the previous label, construct an optical link label according to each second available link, and put it into the second queue, wherein the source node of the second available link is the destination node of the second label; If the destination node of the second label is not the destination node of the first label, and the second queue is not empty, a new second label is retrieved; If the sink node of the second label is the sink node of the first label, then the links corresponding to the second label and all its forward labels are connected to obtain the optimal optical channel path; If the equivalent OSNR value of the optimal optical channel path is less than the OSNR threshold of the first label, the optimal optical channel path is determined as the target path.

[0065] In this embodiment, the management mechanism of the optical link label and the second queue is similar to the management mechanism of the optical channel label and the first queue. The optical link is extended from the source node of the first label to the sink node of the first label. In the extended path, different paths do not intersect, and a single path does not form a loop.

[0066] Furthermore, in one embodiment, the requirement for an available link also includes: there is no optical link label that has the same sink node and has been removed.

[0067] In this embodiment, if there is an optical link label whose sink node is consistent with a link and has been removed, the path extension operation cannot be performed even after the optical link label generated based on the link is placed in the second queue and removed, resulting in unnecessary calculation and time consumption. Therefore, a new restriction condition on available links is added to further reduce the calculation amount and improve routing calculation efficiency.

[0068] Furthermore, in one embodiment, the field of the optical link label also includes an equivalent OSNR value of the constructed path; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the equivalent OSNR value of the constructed path of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0069] In this embodiment, the equivalent OSNR value of the constructed path is additionally considered when determining whether to expand the second label. If the equivalent OSNR value of the constructed path is greater than or equal to the OSNR threshold of the first label, the path is not worth further expansion, and the resulting constructed path will inevitably fail to meet the threshold requirement. This embodiment allows for premature termination of partial path expansion, reducing unnecessary computation and improving algorithm accuracy.

[0070] Furthermore, in one embodiment, the field of the optical link label further includes a total OSNR value, where the total OSNR value is the sum of the equivalent OSNR value of the constructed path and the estimated OSNR value of the unconstructed path; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the total OSNR value of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0071] In this embodiment, when determining whether to expand the second label, the total OSNR value is additionally considered. The total OSNR value is the sum of the equivalent OSNR value of the constructed path and the estimated OSNR value of the unconstructed path. If the total OSNR value is greater than or equal to the OSNR threshold of the first label, the value of further expanding this path is low, and the resulting constructed path is likely to fail to meet the threshold requirement. This embodiment allows for premature termination of partial path expansion, reducing unnecessary computation and improving algorithm accuracy.

[0072] Optionally, the calculation of the equivalent OSNR value of the constructed path may refer to the calculation of the actual forward cost in the optical channel label, and improve the calculation efficiency by iteratively calculating the previous label.

[0073] For example, the cost type involved in the optical channel label includes a link length cost.

[0074] Optionally, the field of the optical link label may also include the actual forward cost, which is quickly calculated by iteratively calculating the previous label, and then the total cost is quickly calculated by adding the estimated cost on the basis of the actual forward cost.

[0075] In a second aspect, an embodiment of the present application also provides a large-scale OTN network routing calculation device.

[0076] Figure 4 A schematic diagram of the functional modules of a large-scale OTN network routing calculation device in one embodiment of the present application is shown.

[0077] Reference Figure 4 In one embodiment, a large-scale OTN network routing calculation device includes: An initialization module 10 is configured to generate an optical channel label according to each first potential optical channel and place the label into a first queue, wherein the source node of the first potential optical channel is the source node of the service, and the fields of the optical channel label include a previous label, a source node, a sink node, a wavelength, a total cost, and an OSNR threshold, where the total cost is the sum of the actual cost of the constructed path and the estimated cost of the unconstructed path; The label extraction module 20 is configured to extract an optical channel label with the minimum total cost from the first queue as a first label; A path construction module 30 is configured to construct a target path if there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, wherein the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label; The label extension module 40 is configured to, if the destination node of the first label is not the destination node of the service and the target path is successfully established, use the first label as the previous label, generate an optical channel label according to each second potential optical channel, and place the optical channel label in the first queue, wherein the source node of the second potential optical channel is the destination node of the first label, and the destination node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels; The callback module 50 is configured to retrieve a new first label if the destination node of the first label is not the destination node of the service and the first queue is not empty; The result output module 60 is configured to connect the target paths corresponding to the first label and all its forward labels to obtain an optimal path for the service if the destination node of the first label is the destination node of the service and the target path is successfully constructed.

[0078] Furthermore, in one embodiment, the path construction module 30 is configured to: Constructing an optical link label according to the first available link and placing the label into the second queue, wherein requirements for the available link include: the sink node does not appear in the target paths corresponding to all forward labels of the first label, the wavelength of the first label is not occupied, the source node of the first available link is the source node of the first label, and the fields of the optical link label include the previous label, the sink node, and the total cost; Taking an optical link label with the minimum total cost from the second queue as the second label; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label with the same destination node as the second label that has been extracted, then use the second label as the previous label, construct an optical link label according to each second available link, and put it into the second queue, wherein the source node of the second available link is the destination node of the second label; If the destination node of the second label is not the destination node of the first label, and the second queue is not empty, a new second label is retrieved; If the sink node of the second label is the sink node of the first label, then the links corresponding to the second label and all its forward labels are connected to obtain the optimal optical channel path; If the equivalent OSNR value of the optimal optical channel path is less than the OSNR threshold of the first label, the optimal optical channel path is determined as the target path.

[0079] Furthermore, in one embodiment, the requirement for an available link also includes: there is no optical link label that has the same sink node and has been removed.

[0080] Furthermore, in one embodiment, the field of the optical link label also includes an equivalent OSNR value of the constructed path; The path construction module 30 is used to: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the equivalent OSNR value of the constructed path of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0081] Furthermore, in one embodiment, the field of the optical link label further includes a total OSNR value, where the total OSNR value is the sum of the equivalent OSNR value of the constructed path and the estimated OSNR value of the unconstructed path; The path construction module 30 is used to: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the total OSNR value of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

[0082] Furthermore, in one embodiment, there is no optical channel label whose sink node and wavelength are consistent with the second potential optical channel and has been removed.

[0083] Furthermore, in one embodiment, the cost types involved in the optical channel label include wavelength cost, local group cost, relay cost, and link length cost.

[0084] Furthermore, in one embodiment, before the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, and actual relay cost of the label and all its forward labels, the actual link length cost of all forward labels, the estimated link length cost of the label, and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the sink node of the label to the sink node of the service; After the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, actual relay cost, and actual link length cost of the label and all its forward labels, as well as the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the label's sink node to the service's sink node.

[0085] Furthermore, in one embodiment, the large-scale OTN network routing calculation device further includes a channel identification module, which is configured to: Calculate the minimum link length between every two nodes using Dijkstra algorithm; If the minimum link length between any two nodes is less than a preset length threshold, it is determined that there is a potential optical channel between the two nodes, where the wavelength of the potential optical channel is a wavelength that can be emitted by the source node and received by the sink node.

[0086] The functional implementation of each module in the large-scale OTN network route calculation device corresponds to each step in the large-scale OTN network route calculation method embodiment, and their functions and implementation processes are not repeated here.

[0087] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0088] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0089] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0090] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0091] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0092] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of this application.

[0093] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A large-scale OTN network routing calculation method, characterized in that: The large-scale OTN network routing calculation method includes: Generate an optical channel label for each first potential optical channel and place it in the first queue, where the source node of the first potential optical channel is the source node of the service, and the fields of the optical channel label include the previous label, source node, sink node, wavelength, total cost, and OSNR threshold, where the total cost is the sum of the actual cost of the established path and the estimated cost of the unestablished path; Taking an optical channel label with the smallest total cost from the first queue as the first label; If there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, construct a target path, where the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label; If the sink node of the first label is not the sink node of the service and the target path is successfully established, the first label is used as the previous label, and an optical channel label is generated according to each second potential optical channel, and the optical channel label is placed in the first queue, wherein the source node of the second potential optical channel is the sink node of the first label, and the sink node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels; If the sink node of the first label is not the sink node of the service and the first queue is not empty, a new first label is retrieved; If the destination node of the first label is the destination node of the service and the target path is successfully constructed, the target paths corresponding to the first label and all its forward labels are connected to obtain the optimal path for the service.

2. The large-scale OTN network routing calculation method according to claim 1, characterized in that: The steps of constructing the target path include: Constructing an optical link label according to the first available link and placing the label into the second queue, wherein requirements for the available link include: the sink node does not appear in the target paths corresponding to all forward labels of the first label, the wavelength of the first label is not occupied, the source node of the first available link is the source node of the first label, and the fields of the optical link label include the previous label, the sink node, and the total cost; Taking an optical link label with the minimum total cost from the second queue as the second label; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label with the same destination node as the second label that has been extracted, then use the second label as the previous label, construct an optical link label according to each second available link, and put it into the second queue, wherein the source node of the second available link is the destination node of the second label; If the destination node of the second label is not the destination node of the first label, and the second queue is not empty, a new second label is retrieved; If the sink node of the second label is the sink node of the first label, then the links corresponding to the second label and all its forward labels are connected to obtain the optimal optical channel path; If the equivalent OSNR value of the optimal optical channel path is less than the OSNR threshold of the first label, the optimal optical channel path is determined as the target path.

3. The large-scale OTN network routing calculation method according to claim 2, characterized in that: The requirement for an available link also includes: there is no optical link label that is consistent with the sink node and has been removed.

4. The large-scale OTN network routing calculation method according to claim 2, wherein: The field of the optical link label also includes the equivalent OSNR value of the constructed path; If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the equivalent OSNR value of the constructed path of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

5. The large-scale OTN network routing calculation method according to claim 2, wherein: The optical link label also includes a total OSNR value, which is the sum of the equivalent OSNR value of the constructed path and the estimated OSNR value of the unconstructed path. If the destination node of the second label is not the destination node of the first label, and there is no other optical link label whose destination node is consistent with the second label and has been taken out, the second label is used as the previous label, an optical link label is constructed according to each second available link, and the step of placing the optical link label in the second queue includes: If the destination node of the second label is not the destination node of the first label, there is no other optical link label with the same destination node as the second label that has been taken out, and the total OSNR value of the second label is less than the OSNR threshold of the first label, then the second label is used as the previous label, and an optical link label is constructed according to each second available link and placed in the second queue.

6. The large-scale OTN network routing calculation method according to any one of claims 1 to 5, characterized in that: There is no optical channel label whose sink node and wavelength are consistent with the second potential optical channel and has been removed.

7. The large-scale OTN network routing calculation method according to any one of claims 1 to 5, characterized in that: The cost types involved in optical channel labels include wavelength cost, local group cost, relay cost, and link length cost.

8. The large-scale OTN network routing calculation method according to claim 7, wherein: Before the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, and actual relay cost of the label and all its forward labels, the actual link length cost of all forward labels, the estimated link length cost of the label, and the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the sink node of the label to the sink node of the service; After the target path corresponding to an optical channel label is constructed, the total cost of the label includes: the actual wavelength cost, actual local group cost, actual relay cost, and actual link length cost of the label and all its forward labels, as well as the estimated wavelength cost, estimated local group cost, estimated relay cost, and estimated link length cost from the label's sink node to the service's sink node.

9. The large-scale OTN network routing calculation method according to any one of claims 1 to 5, characterized in that: Before the step of generating an optical channel label according to each first potential optical channel and placing the optical channel label into the first queue, the method further includes: Calculate the minimum link length between every two nodes using Dijkstra algorithm; If the minimum link length between any two nodes is less than a preset length threshold, it is determined that there is a potential optical channel between the two nodes, where the wavelength of the potential optical channel is a wavelength that can be emitted by the source node and received by the sink node.

10. A large-scale OTN network routing calculation device, characterized in that: The large-scale OTN network routing calculation device includes: an initialization module, configured to generate an optical channel label according to each first potential optical channel and place the label into a first queue, wherein the source node of the first potential optical channel is the source node of the service, and the fields of the optical channel label include a previous label, a source node, a sink node, a wavelength, a total cost, and an OSNR threshold, where the total cost is the sum of an actual cost of a constructed path and an estimated cost of an unconstructed path; a label extraction module, configured to extract an optical channel label with the minimum total cost from the first queue as a first label; a path construction module, configured to construct a target path if there is no other optical channel label whose sink node and wavelength are consistent with the first label and has been removed, wherein the target path meets the source node, sink node, wavelength and OSNR threshold requirements of the first label; a label extension module configured to, if the destination node of the first label is not the destination node of the service and the target path is successfully established, use the first label as the previous label, generate an optical channel label according to each second potential optical channel, and place the optical channel label in the first queue, wherein the source node of the second potential optical channel is the destination node of the first label, and the destination node of the second potential optical channel does not appear in the target path corresponding to the first label and all its forward labels; A callback module, configured to retrieve a new first label if the destination node of the first label is not the destination node of the service and the first queue is not empty; The result output module is configured to connect the target paths corresponding to the first label and all its forward labels to obtain the optimal path for the service if the destination node of the first label is the destination node of the service and the target path is successfully constructed.

Images