A protection path determination method

Abstract

The present disclosure relates to the field of communication technology, and in particular to a method for determining a protection path, comprising: obtaining an initial protection path of a target service from a preset network, the initial protection path comprising at least one protection sub-path, the protection sub-path comprising multiple fiber cores; for each protection sub-path, obtaining the spectrum matching degree between each fiber core of the protection sub-path and the target service, the spectrum matching degree characterizing the matching degree between the frequency gap required by the target service and the frequency gap of the fiber core; determining the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path as the target fiber core of the protection sub-path; verifying the preset spectrum conditions for the target fiber core; if the target fiber core meets the preset spectrum conditions, determining the target protection path of the target service based on the target fiber core. The present disclosure can improve the utilization efficiency of spectrum resources and improve the reliability of the network.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a protection path determination method. Background Art

[0002] At present, the application prospects of multi-core optical fiber are becoming more and more broad. It allows multiple independent optical signals to be transmitted in the same physical transmission medium, thereby effectively increasing the transmission capacity of the network. This means that more data can be transmitted without increasing the number of optical fibers, meeting the growing bandwidth demand.

[0003] With the widespread deployment of flexible grid technology and multi-core optical fiber, network reliability and survivability issues have also emerged. In this type of optical network, there may be coupling effects between channels, and multiple channels share the same optical fiber, which means that once a part of the optical fiber fails, multiple channels may be affected. Therefore, the selection of protection paths and the design of protection schemes are crucial.

[0004] However, the current survivability issues of services running in the network focus more on the selection of working paths. When selecting paths, more consideration is given to inter-core crosstalk, and spectrum utilization is not considered. Therefore, there is currently a lack of effective solutions for determining protection paths to provide stable protection for services and ensure that the resources of the optical network can be effectively utilized. Summary of the invention

[0005] The purpose of the present disclosure is to provide a protection path determination method, which can reduce spectrum fragmentation, improve spectrum utilization, and improve network reliability.

[0006] In order to achieve the above object, the present disclosure provides a protection path determination method, comprising:

[0007] Acquire an initial protection path of a target service from a preset network, wherein the initial protection path includes at least one protection sub-path, and the protection sub-path includes a plurality of fiber cores;

[0008] For each protection sub-path, obtaining a spectrum matching degree between each fiber core of the protection sub-path and the target service, wherein the spectrum matching degree represents a matching degree between a frequency slot required by the target service and a frequency slot of the fiber core;

[0009] Determine the fiber core with the highest frequency spectrum matching degree among the multiple fiber cores of the protection sub-path as the target fiber core of the protection sub-path;

[0010] Verifying a preset spectrum condition on the target fiber core;

[0011] If the target fiber core meets the preset spectrum condition, a target protection path for the target service is determined based on the target fiber core.

[0012] Further, the obtaining of the spectrum matching degree between each fiber core of the protection sub-path and the target service includes:

[0013] For each fiber core of the protection subpath, obtaining a remaining time difference of a frequency slot corresponding to the fiber core, a first number of spectrum blocks in the fiber core that match the target service, a second number of spectrum blocks continuously available on the fiber core, a third number of frequency slots occupied by each idle spectrum block in the fiber core, and a fourth number of frequency slots required by the target service;

[0014] The degree of spectrum matching between the fiber core and the target service is determined based on the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required for the target service.

[0015] Further, the obtaining of the remaining time difference of the frequency slot corresponding to the fiber core includes:

[0016] Acquire the running time of the target service and the remaining running time of each frequency slot service adjacent to the target service in the fiber core;

[0017] The remaining time difference of the frequency slot corresponding to the fiber core is determined according to the running time and the remaining running time.

[0018] Further, determining the remaining time difference of the frequency slot corresponding to the fiber core according to the running time and the remaining running time includes:

[0019] Substitute the running time and the remaining running time into the following formula for calculation to obtain the remaining time difference of the frequency slot corresponding to the fiber core:

[0020]

[0021] Where, ΔT i is the remaining time difference of the frequency slot corresponding to the i-th fiber core, is the running time, is the remaining running time of the nth frequency slot service adjacent to the target service in the fiber core, and N is the number of all frequency slots that can be adjacent to the target service in the fiber core.

[0022] Further, determining the degree of spectrum matching between the fiber core and the target service according to the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service includes:

[0023] Substitute the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service into the following formula to calculate the spectrum matching degree between the fiber core and the target service:

[0024]

[0025] Among them, BSM i is the spectrum matching degree between the i-th fiber core and the target service, G m is the first quantity, G f For the second quantity, B j is the third number, j represents the jth spectrum block, B s is the fourth quantity.

[0026] Furthermore, the method further comprises:

[0027] If the target fiber core does not meet the preset spectrum condition, the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path except the target fiber core is determined as a new target fiber core;

[0028] The step of verifying the preset spectrum condition of the target core is returned based on the new target core until the new target core meets the preset spectrum condition.

[0029] Further, the preset network includes a plurality of network nodes, and the obtaining an initial protection path of the target service from the preset network includes:

[0030] Acquire a source node and a sink node corresponding to the target service from among the multiple network nodes;

[0031] Determine a plurality of candidate paths from the plurality of network nodes based on the source node and the sink node;

[0032] Acquire a path length of each of the candidate paths, and determine a working path for the target service from the multiple candidate paths according to the path length;

[0033] Filtering network nodes covered by the working path of the target service from the multiple network nodes to obtain multiple candidate network nodes;

[0034] The initial protection path is determined from the plurality of candidate network nodes based on the source node and the sink node.

[0035] Further, the determining the initial protection path from the multiple candidate network nodes based on the source node and the sink node includes:

[0036] Determine at least one candidate protection path among the multiple candidate network nodes according to the source node and the sink node;

[0037] The candidate protection path with the shortest path among the at least one candidate protection path is used as the initial protection path.

[0038] Further, determining the working path of the target service from the multiple candidate paths according to the path length includes:

[0039] Determine the candidate path with the shortest path length among the multiple candidate paths as the initial working path;

[0040] Verifying a preset spectrum condition on the initial working path;

[0041] If the initial working path meets the preset spectrum condition, using the initial working path as the working path;

[0042] If the initial working path does not meet the preset spectrum condition, the candidate path with the shortest path length among the multiple candidate paths except the initial working path is determined as a new initial working path, and based on the new initial working path, the step of verifying the preset spectrum condition of the initial working path is returned to be executed until the new initial working path meets the preset spectrum condition.

[0043] Further, the verifying of the preset spectrum condition of the target core includes:

[0044] Performing spectrum consistency verification and spectrum continuity verification on the target fiber core;

[0045] If the target fiber core satisfies the spectrum consistency and the spectrum continuity, it is determined that the target fiber core satisfies the preset spectrum condition.

[0046] In this embodiment, the initial protection path of the target service is obtained from the preset network, the initial protection path includes at least one protection sub-path, and the protection sub-path includes multiple fiber cores; and for each protection sub-path, the spectrum matching degree between each fiber core of the protection sub-path and the target service is obtained, and the spectrum matching degree represents the matching degree between the frequency gap required by the target service and the frequency gap of the fiber core; then the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path is determined as the target fiber core of the protection sub-path; then, the preset spectrum condition is verified for the target fiber core; if the target fiber core meets the preset spectrum condition, the target protection path of the target service is determined based on the target fiber core. Thus, the resource utilization of the protection path is emphasized, the spectrum matching degree measurement index is proposed, the spectrum resources with high matching degree are intelligently selected, the spectrum fragmentation is minimized, a better core selection scheme is provided for the multi-core optical fiber in the protection path, the utilization efficiency of the spectrum resources is improved, and the reliability of the network is improved.

[0047] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0049] Figure 1 is a flow chart of a method for determining a protection path according to an exemplary embodiment of the present disclosure;

[0050] Figure 2 is a schematic diagram showing the distribution of the fiber cores when the working path is a seven-core optical fiber according to an exemplary embodiment of the present disclosure;

[0051] Figure 3 is a specific flow chart of a method for selecting a service-aware protection path based on spectrum matching according to an exemplary embodiment of the present disclosure;

[0052] Figure 4 is a network topology diagram of a preset network according to an exemplary embodiment of the present disclosure;

[0053] Figure 5 is a schematic diagram showing a working path selected in a network topology diagram according to an exemplary embodiment of the present disclosure;

[0054] Figure 6 is a schematic diagram showing an initial protection path selected in a network topology diagram according to an exemplary embodiment of the present disclosure;

[0055] Figure 7It is a spectrum resource occupancy situation of path AE under the requirement of dedicated protection according to an exemplary embodiment of the present disclosure;

[0056] Figure 8 It is a spectrum resource occupancy situation of path DE under the requirement of dedicated protection according to an exemplary embodiment of the present disclosure;

[0057] Fig. 9 It is a condition of occupancy of spectrum resources of path EC under the requirement of dedicated protection according to an exemplary embodiment of the present disclosure;

[0058] Fig.10 It is a spectrum resource occupancy situation of path AE under the requirement of shared protection according to an exemplary embodiment of the present disclosure;

[0059] Fig.11 It is a spectrum resource occupancy situation of path DE under the requirement of shared protection according to an exemplary embodiment of the present disclosure;

[0060] Fig.12 The figure shows the occupation of spectrum resources of path EC under the requirement of shared protection according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0061] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0062] In the description of the present disclosure, it should be noted that the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present disclosure, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0064] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0065] The power communication network will face profound changes in response to the major technical requirements for the construction of new power systems. With the widespread application of digital technologies represented by "cloud, big data, Internet of Things, mobile, intelligence and chain" in power systems, power grid services will show a trend of "broadband, networking, IP and diversification", which puts forward higher requirements on the carrying capacity, access flexibility and multi-service adaptability of the power communication backbone transmission network. At the same time, as the demand for power services becomes increasingly rich and diverse, the requirements for capacity and latency are becoming more stringent. The development of power optical transmission networks has limitations, and it is necessary to find new network architectures and implementation methods to improve the resource adaptability and flexibility of the network. After years of research, the elastic optical network has broken through this bottleneck with its flexible grid technology. It uses the spectrum with finer spectrum granularity and in a more flexible way, and can adjust the spectrum allocated to the channel according to channel requirements. Unlike the previous "one-size-fits-all model", the flexible grid technology effectively improves the utilization of the spectrum by allocating spectrum resources on demand, significantly expanding the overall network capacity.

[0066] On the other hand, the application prospects of multi-core optical fiber are becoming more and more broad. It allows multiple independent optical signals to be transmitted in the same physical transmission medium, which effectively increases the transmission capacity of the network. This means that more data can be transmitted without increasing the number of optical fibers to meet the growing bandwidth demand. However, with the widespread deployment of flexible grid technology and multi-core optical fiber, network reliability and survivability issues have also emerged. In this type of optical network, there may be coupling effects between channels, and multiple channels share the same optical fiber, which means that once a part of the optical fiber fails, multiple channels may be affected. Therefore, the selection of protection paths and the design of protection schemes are crucial.

[0067] The inventors have found that currently in the space-division multiplexing elastic optical network, more attention is paid to the core selection scheme of the working path for survivability issues, and more consideration is given to inter-core crosstalk without designing the scheme from the perspective of spectrum utilization and protection path redundant resource utilization. Therefore, it is currently impossible to effectively determine a better protection path to reduce spectrum fragmentation and improve spectrum utilization while protecting the stable operation of the service.

[0068] In view of this, the present disclosure provides a protection path determination method that can reduce spectrum fragmentation and improve spectrum utilization.

[0069] Figure 1 is a flowchart of a method for determining a protection path according to an exemplary embodiment of the present disclosure, see Figure 1 , the protection path determination method may include the following steps:

[0070] S110: Acquire an initial protection path of a target service from a preset network, where the initial protection path includes at least one protection sub-path, and the protection sub-path includes multiple fiber cores.

[0071] The preset network may be a space division multiplexing elastic optical network (SDM-EONs). The preset network may be composed of multiple network nodes. It is understood that each network node may represent a network device with communication functions, such as a router, a mobile terminal, etc., which is not limited here.

[0072] The target service may refer to a service that needs to use a preset network to achieve data transmission. Before running the target service, a communication link corresponding to the target service needs to be established in the preset network. It can be understood that the communication link may be composed of at least two network nodes in the preset network. The communication link may also be called a communication path. The communication path may include a working path and a protection path. The working path may be a path used when running the target service. The protection path may refer to a backup path used to ensure that the target service can continue to run when a working path fails.

[0073] It is understandable that, for an initial protection path, the network nodes covered by the initial protection path may be divided into at least one protection sub-path. To ensure communication stability, each protection sub-path may not exceed a specified length, wherein the specified length corresponds to a distance in reality.

[0074] S120: For each protection sub-path, obtain a spectrum matching degree between each fiber core of the protection sub-path and a target service, where the spectrum matching degree represents a matching degree between a frequency slot required by the target service and a frequency slot of the fiber core.

[0075] S130: Determine the fiber core with the highest frequency spectrum matching degree among the multiple fiber cores of the protection sub-path as the target fiber core of the protection sub-path.

[0076] S140: Verify preset spectrum conditions on the target fiber core.

[0077] The preset spectrum condition may be a condition for verifying the spectrum consistency and / or spectrum continuity of the target fiber core.

[0078] S150: If the target fiber core meets the preset spectrum condition, determine a target protection path for the target service based on the target fiber core.

[0079] It can be seen that in this embodiment, by obtaining the initial protection path of the target service from the preset network, the initial protection path includes at least one protection sub-path, and the protection sub-path includes multiple fiber cores; and for each protection sub-path, the spectrum matching degree between each fiber core of the protection sub-path and the target service is obtained, and the spectrum matching degree represents the matching degree between the frequency gap required by the target service and the frequency gap of the fiber core; then, the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path is determined as the target fiber core of the protection sub-path; then, the preset spectrum condition is verified for the target fiber core; if the target fiber core meets the preset spectrum condition, the target protection path of the target service is determined based on the target fiber core. Thus, the resource utilization of the protection path is focused on, and a spectrum matching degree measurement index is proposed, and the spectrum resource (i.e., fiber core) with the highest matching degree is intelligently selected, which minimizes spectrum fragmentation, provides a better core selection scheme for multi-core optical fibers in the protection path, improves the utilization efficiency of spectrum resources, and improves the reliability of the network.

[0080] In some implementations, in step S110, a specific implementation of obtaining an initial protection path of a target service from a preset network may include:

[0081] S111, obtaining a source node and a sink node corresponding to a target service from a plurality of network nodes;

[0082] S112, determining multiple candidate paths from multiple network nodes based on the source node and the sink node;

[0083] S113, obtaining the path length of each candidate path, and determining a working path for the target service from the multiple candidate paths according to the path length;

[0084] In step S113, a specific implementation of determining a working path of a target service from a plurality of candidate paths according to the path length may include:

[0085] S1131: Determine a candidate path with the shortest path length among multiple candidate paths as an initial working path.

[0086] S1132: Verify the preset spectrum condition of the initial working path.

[0087] S1133: If the initial working path meets the preset spectrum condition, use the initial working path as the working path.

[0088] S1134: If the initial working path does not meet the preset spectrum condition, a candidate path with the shortest path length among multiple candidate paths except the initial working path is determined as a new initial working path, and based on the new initial working path, the step of verifying the preset spectrum condition of the initial working path is returned until the new initial working path meets the preset spectrum condition.

[0089] Exemplarily, the space-division multiplexing elastic optical network can be initialized to generate a service connection request. Then, in response to the service connection request, a working path for the target service is established. In the process of establishing the working path for the target service, a KSP algorithm is used in the selection of routes to calculate the kth shortest path, and the k shortest paths are judged from shortest to longest in order whether the path can carry the working frequency slot of the service.

[0090] In terms of selecting the fiber cores of the working path, this embodiment may prioritize the fiber cores. The non-central fiber cores are set as the first priority, the central fiber cores are set as the second priority, and the fiber cores of the first priority are preferentially used. For example, Figure 2 As shown, Figure 2 A seven-core optical fiber is shown, each non-central core (such as Figure 2 There will be crosstalk effects of three fiber cores around the cores (Core1, Core2, Core3, Core4, Core5, Core6), while there are six fiber cores around the center core (such as Figure 2 After the core selection is completed, the spectrum continuity and spectrum consistency requirements need to be met, that is, the above-mentioned preset spectrum conditions are met. The first hit algorithm is used for spectrum allocation. When allocating spectrum resources, service requests try to avoid allocating the same frequency slot resources on adjacent cores of the same link.

[0091] It can be seen that in this embodiment, a fiber core with a shorter path and stronger anti-interference ability can be preferentially selected as a working path.

[0092] S114, filtering network nodes covered by the working path of the target service from the multiple network nodes to obtain multiple candidate network nodes.

[0093] S115 , determining an initial protection path from a plurality of candidate network nodes based on the source node and the sink node.

[0094] In some implementations, in step S115, a specific implementation of determining an initial protection path from a plurality of candidate network nodes based on a source node and a sink node may include:

[0095] S1151 : Determine at least one candidate protection path among multiple candidate network nodes according to a source node and a sink node.

[0096] S1152: Use the shortest candidate protection path among at least one candidate protection path as an initial protection path.

[0097] Exemplarily, for the currently established working path, the link corresponding to the working path can be deleted in the network topology of the preset network, and the KSP algorithm is used to re-establish the kth shortest path based on the source and destination nodes of the service request of the target service, and then the shortest path is determined as the initial protection path, that is, k initial protection paths are obtained.

[0098] In some implementations, in step S120, a specific implementation of obtaining the spectrum matching degree between each fiber core of the protection sub-path and the target service may include:

[0099] S121, for each fiber core of the protection subpath, obtain the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of continuously available spectrum blocks on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required for the target service.

[0100] Among them, it can be understood that the remaining time difference of the frequency slot corresponding to the above-mentioned fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of continuously available spectrum blocks on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required for the target service can be obtained by detecting the fiber core in real time.

[0101] In order to better improve the utilization efficiency of protection resources and minimize the degree of fragmentation in the network, this embodiment can measure the spectrum matching degree from two perspectives: the time domain and the frequency domain.

[0102] First, from the perspective of the time domain, a measurement index of the remaining time difference of the frequency slot is proposed to describe the time difference between the service running time and the remaining running time of all possible adjacent frequency slots in the service matching process. Under normal circumstances, it is the best situation for consecutive adjacent services to leave at the same time. In this case, there will be no small and independently unavailable frequency slots. Therefore, when a service arrives, the smaller the difference between the remaining running time of the service of the adjacent frequency slot and the running time of the currently arriving service, the better. Therefore, the fiber core can be measured from the perspective of the time domain by the remaining time difference of the frequency slot corresponding to the fiber core. It can be understood that in this embodiment, the currently arriving service can be the above-mentioned target service.

[0103] In some implementations, in step S121, a specific implementation of obtaining the remaining time difference of the frequency slot corresponding to the fiber core may include:

[0104] S1211, obtaining the running time of the target service and the remaining running time of each frequency slot service adjacent to the target service in the fiber core.

[0105] The running time of the target service also indicates the running time of the arrival service.

[0106] S1212, determining a remaining time difference of a frequency slot corresponding to the fiber core according to the running time and the remaining running time.

[0107] In step S1212, the specific implementation of determining the remaining time difference of the frequency slot corresponding to the fiber core according to the running time and the remaining running time may include:

[0108] Substitute the running time and the remaining running time into the following formula to calculate the remaining time difference of the frequency slot corresponding to the fiber core:

[0109]

[0110] Where, ΔT i is the remaining time difference of the frequency slot corresponding to the i-th fiber core, is the running time, is the remaining running time of the nth frequency slot service adjacent to the target service in the fiber core, and N is the number of all frequency slots that can be adjacent to the target service in the fiber core.

[0111] S122, determine the spectrum matching degree between the fiber core and the target service according to the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required for the target service.

[0112] Secondly, from the perspective of frequency domain, an indicator is proposed to calculate the spectrum matching degree according to the frequency slots required by the service. This indicator takes into account the possibility of complete matching and incomplete matching of spectrum fragmentation between the frequency slots required by the service and the idle frequency slots of the fiber core. Complete matching refers to idle spectrum blocks that are exactly equal to the number of frequency slots required by the service, and incomplete matching refers to the measurement of spectrum fragmentation generated when the number of frequency slots in the idle spectrum block is greater than the number of frequency slots required by the service. By combining the time domain and the frequency domain, the core resources in the spatial dimension are selected.

[0113] In some implementations, in step S122, according to the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service, a specific implementation method of determining the spectrum matching degree between the fiber core and the target service may include:

[0114] Substitute the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service into the following formula to calculate the spectrum matching degree between the fiber core and the target service:

[0115]

[0116] Among them, BSM i is the spectrum matching degree between the i-th fiber core and the target service, G m is the first quantity (i.e. G m represents the number of spectrum blocks that fully match the service size), G f is the second quantity (i.e. G f represents the number of continuously available spectrum blocks on the fiber core), j represents the jth spectrum block, B j is the third quantity (i.e. B j represents the number of frequency slots occupied by the jth idle spectrum block), B s The fourth quantity (i.e. B s represents the number of frequency slots required by the service request of the target service). In the above formula, i The reason for adding 1 is to avoid the situation where the denominator is 0.

[0117] In some implementations, after step S140, the method further includes:

[0118] If the target fiber core does not meet the preset spectrum condition, the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path except the target fiber core is determined as the new target fiber core;

[0119] The step of verifying the preset spectrum condition of the target core is returned based on the new target core until the new target core meets the preset spectrum condition.

[0120] In step S140, a specific implementation of verifying the preset spectrum condition of the target core may include:

[0121] Perform spectrum consistency verification and spectrum continuity verification on the target fiber core.

[0122] If the target fiber core satisfies the spectrum consistency and the spectrum continuity, it is determined that the target fiber core satisfies the preset spectrum condition.

[0123] Exemplarily, after k initial protection paths are obtained through step S110, k shortest paths can be traversed, and the spectrum matching degree BSM of each fiber core on each link of the current path can be calculated according to the frequency gap size required by the service. Due to different protection requirement levels of the services, the corresponding spectrum matching degree calculation methods are also different. According to the size of the BSM value of each fiber core (i.e., the above-mentioned spectrum matching degree), each link is arranged in descending order in set C.

[0124] Then, according to the calculation results of the previous step, each link on the current path traverses the fiber core resources from its own set C. If the core selection result meets the requirements of spectrum continuity and spectrum consistency, the path successfully carries the protection resources of the service. If there is no satisfactory fiber core, the next path is traversed until a path is found to allocate the protection frequency slot. If not found, the service is blocked.

[0125] In some implementations, unlike the working path, the establishment of the service protection path can also be determined in combination with the service protection requirement level. For example, in this embodiment, the service protection requirement level can be divided into three categories: allowing dedicated protection, allowing shared protection, and not requiring protection. Different protection path determination strategies are adopted for different protection requirement levels.

[0126] As a more specific example, Figure 3 As shown, Figure 3 The specific flow chart of the service-aware protection path selection method based on spectrum matching is as follows: Figure 3 It can be known that the protection path selection method can be determined by a service generation module, a working path establishment module, and a protection path establishment module.

[0127] For example, in the service generation stage by the service generation module, Figure 4 In the topology shown, the source node of service S is set to A, the sink node is set to C, and the working frequency slot and protection frequency slot of the target service are determined to be 2, and the service duration is 2s. Then, routing and core selection spectrum allocation are performed.

[0128] During the work path establishment phase through the work path establishment module, when the target service arrives, the KSP algorithm is first used to calculate the kth shortest path. According to the selection method of first traversing the non-central core, the First-Fit algorithm is used to allocate spectrum resources. If the conditions of spectrum resource allocation continuity and consistency are met, the path can carry the service. If the path cannot meet the conditions of spectrum resource allocation, the next path will be judged in sequence. Figure 5 As shown: The final selected working path is ABC, that is, Figure 5 The dotted line corresponds to the path.

[0129] In the protection path establishment phase through the protection path establishment module, after the working path is established, the links occupied by the working path in the topology are deleted to form a new topology, and k shortest paths are generated by the KSP algorithm and traversed in sequence. Figure 6 As shown in Figure 1, we first select the shortest path ADEC as the initial protection path, that is, Figure 6 The path corresponding to the medium thick line. Calculate the spectrum matching degree of each fiber core according to different service protection requirement levels.

[0130] Then, the protection requirement level of the target service (such as the service S mentioned above) is obtained.

[0131] When the service protection requirement level of service S is: dedicated protection. Figures 7 to 9 As shown, the spectrum resource occupancy of each fiber core of links AD, DE, and EC for services with high protection requirements and the remaining operating time of each frequency slot are respectively shown.

[0132] Among them, the residual time difference of the frequency slot corresponding to each fiber core in path AD is:

[0133] Among them, the spectrum matching degree corresponding to each fiber core in path AD is:

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] Among them, the residual time difference of the frequency slot corresponding to each fiber core in path DE is:

[0142]

[0143] Among them, the spectrum matching degree corresponding to each fiber core in path DE is:

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151] Among them, the remaining time difference of the frequency slot corresponding to each fiber core in the path EC is:

[0152]

[0153] Among them, the spectrum matching degree corresponding to each fiber core in path EC is:

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161] By calculating the BSM value of the spectrum matching degree of each fiber core and arranging them in descending order and listing them in set C, it can be known from the calculation that C AD ={2,7,3,5,4,1,6}, C DE ={4,7,2,5,6,3,1}, C EC ={2,3,4,6,1,5,7}, under the condition of meeting the spectrum consistency and spectrum continuity requirements, select the cores from the largest to the smallest in the set C to carry the service. The final selection result is that AD and EC select the 7th-8th frequency slot of the No. 2 core, and DE selects the 7th-8th frequency slot of the No. 4 core.

[0162] When the service protection requirement level of service S is: shared protection. Figures 10 to 12 As shown, the spectrum resource occupancy of each fiber core of links AD, DE, and EC for services with medium protection requirements is shown.

[0163] Among them, the residual time difference of the frequency slot corresponding to each fiber core in path AD is:

[0164] Among them, the spectrum matching degree corresponding to each fiber core in path AD is:

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172] Among them, the residual time difference of the frequency slot corresponding to each fiber core in path DE is:

[0173]

[0174] Among them, the spectrum matching degree corresponding to each fiber core in path DE is:

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182] Among them, the remaining time difference of the frequency slot corresponding to each fiber core in the path EC is:

[0183]

[0184] Among them, the spectrum matching degree corresponding to each fiber core in path EC is:

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192] It can be seen that for services that allow shared protection, the shared protection resources in the spectrum are available resources. By calculating the BSM value of the spectrum matching degree of each core and arranging them in descending order and listing them in set C, it can be known from the calculation that C AD ={3,1,6,2,4,7,5}, C DE ={3,4,5,6,7,2,1}, C EC ={3,2,6,5,7,1,4}, under the condition of meeting the spectrum consistency and spectrum continuity requirements, the fiber cores are selected from the largest to the smallest in the set C to carry the service. Finally, the three links are selected from the 1st to 2nd frequency slots of the 3rd fiber core.

[0193] For services that do not require protection, the protection path determination operation may not be performed.

[0194] It can be seen that this embodiment specifically proposes a service-aware protection path selection method based on spectrum matching. In the core selection process of the space-division multiplexing elastic optical network, the spectrum matching degree is designed. This indicator first reduces the spectrum fragmentation generated during the service operation process by comparing the time difference between the service operation time and the remaining operation time of all possible adjacent frequency slots in the matching process in the time domain. Secondly, it measures the complete match and incomplete match of the service protection frequency slot and the idle frequency slot on the fiber core in the frequency domain, and intelligently selects spectrum resources with high matching degree, thereby minimizing the spectrum fragmentation on the optical fiber. In addition, for services with different protection level requirements, the calculation of spectrum matching degree can also be dynamically adjusted. The uncertainty of occupied frequency slots on the fiber core makes the allocation of frequency slots more possible, and the core selection of the protection path is more flexible, which is conducive to improving network reliability. In general, the method implemented in this paper allows the spectrum matching degree of the service to be flexibly calculated according to the protection level requirements of the service, which can better meet the specific needs of different services; secondly, by utilizing the spectrum matching degree of the service, it can more efficiently utilize network resources, reduce spectrum fragmentation and improve the spectrum utilization rate of the network from the two perspectives of time difference and frequency slot matching; finally, it can reduce the switching cost when a network failure occurs, improve the survivability and reliability of the network, and provide more stable transmission services for the power business.

[0195] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0196] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0197] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for determining a protection path, characterized in that: include: Acquire an initial protection path of a target service from a preset network, wherein the initial protection path includes at least one protection sub-path, and the protection sub-path includes a plurality of fiber cores; For each protection sub-path, obtaining a spectrum matching degree between each fiber core of the protection sub-path and the target service, wherein the spectrum matching degree represents a matching degree between a frequency slot required by the target service and a frequency slot of the fiber core; Determine the fiber core with the highest frequency spectrum matching degree among the multiple fiber cores of the protection sub-path as the target fiber core of the protection sub-path; Verifying a preset spectrum condition on the target fiber core; If the target fiber core meets the preset spectrum condition, a target protection path of the target service is determined based on the target fiber core, and the obtaining of the spectrum matching degree between each fiber core of the protection sub-path and the target service includes: For each fiber core of the protection subpath, obtaining a remaining time difference of a frequency slot corresponding to the fiber core, a first number of spectrum blocks in the fiber core that match the target service, a second number of spectrum blocks continuously available on the fiber core, a third number of frequency slots occupied by each idle spectrum block in the fiber core, and a fourth number of frequency slots required by the target service; The degree of spectrum matching between the fiber core and the target service is determined based on the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required for the target service.

2. The method for determining a protection path according to claim 1, characterized in that: The obtaining the remaining time difference of the frequency slot corresponding to the fiber core includes: Acquire the running time of the target service and the remaining running time of each frequency slot service adjacent to the target service in the fiber core; The remaining time difference of the frequency slot corresponding to the fiber core is determined according to the running time and the remaining running time.

3. The method for determining a protection path according to claim 2, characterized in that: The determining, according to the running time and the remaining running time, the remaining time difference of the frequency slot corresponding to the fiber core comprises: Substitute the running time and the remaining running time into the following formula for calculation to obtain the remaining time difference of the frequency slot corresponding to the fiber core: Where, ΔT i is the remaining time difference of the frequency slot corresponding to the i-th fiber core, is the running time, is the remaining running time of the nth frequency slot service adjacent to the target service in the fiber core, and N is the number of all frequency slots that can be adjacent to the target service in the fiber core.

4. The method for determining a protection path according to claim 1, characterized in that: The determining, according to the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service, the spectrum matching degree between the fiber core and the target service comprises: Substitute the remaining time difference of the frequency slot corresponding to the fiber core, the first number of spectrum blocks in the fiber core that match the target service, the second number of spectrum blocks continuously available on the fiber core, the third number of frequency slots occupied by each idle spectrum block in the fiber core, and the fourth number of frequency slots required by the target service into the following formula to calculate the spectrum matching degree between the fiber core and the target service: Among them, BSM i is the spectrum matching degree between the i-th fiber core and the target service, G m is the first quantity, G f For the second quantity, B j is the third number, j represents the jth spectrum block, B s is the fourth quantity.

5. The method for determining a protection path according to claim 1, characterized in that: The method further comprises: If the target fiber core does not meet the preset spectrum condition, the fiber core with the highest spectrum matching degree among the multiple fiber cores of the protection sub-path except the target fiber core is determined as a new target fiber core; The step of verifying the preset spectrum condition of the target core is returned based on the new target core until the new target core meets the preset spectrum condition.

6. The method for determining a protection path according to any one of claims 1 to 5, characterized in that: The preset network includes a plurality of network nodes, and the obtaining of an initial protection path of a target service from the preset network includes: Acquire a source node and a sink node corresponding to the target service from among the multiple network nodes; Determine a plurality of candidate paths from the plurality of network nodes based on the source node and the sink node; Acquire a path length of each of the candidate paths, and determine a working path for the target service from the multiple candidate paths according to the path length; Filtering network nodes covered by the working path of the target service from the multiple network nodes to obtain multiple candidate network nodes; The initial protection path is determined from the plurality of candidate network nodes based on the source node and the sink node.

7. The method for determining a protection path according to claim 6, characterized in that: The determining the initial protection path from the plurality of candidate network nodes based on the source node and the sink node includes: Determine at least one candidate protection path among the multiple candidate network nodes according to the source node and the sink node; The candidate protection path with the shortest path among the at least one candidate protection path is used as the initial protection path.

8. The method for determining a protection path according to claim 6, characterized in that: The determining the working path of the target service from the multiple candidate paths according to the path length includes: Determine the candidate path with the shortest path length among the multiple candidate paths as the initial working path; Verifying a preset spectrum condition on the initial working path; If the initial working path meets the preset spectrum condition, using the initial working path as the working path; If the initial working path does not meet the preset spectrum condition, the candidate path with the shortest path length among the multiple candidate paths except the initial working path is determined as a new initial working path, and based on the new initial working path, the step of verifying the preset spectrum condition of the initial working path is returned to be executed until the new initial working path meets the preset spectrum condition.

9. The method for determining a protection path according to any one of claims 1 to 5, characterized in that: The verifying of the preset spectrum condition of the target fiber core includes: Performing spectrum consistency verification and spectrum continuity verification on the target fiber core; If the target fiber core satisfies the spectrum consistency and the spectrum continuity, it is determined that the target fiber core satisfies the preset spectrum condition.

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