Spectrum allocation method applied to hybrid optical fiber network and readable storage medium

Abstract

The invention relates to the technical field of spectrum allocation, and discloses a spectrum allocation method applied to a hybrid optical fiber network and a readable storage medium, and the method comprises the steps: building a plurality of spectrum window planes in a modulation format based on the hybrid optical fiber network topology by taking the number of frequency slots required by a to-be-transmitted service as the spectrum width, selecting the shortest path to construct an optical fiber selection scheme, and calculating the transmission cost to select a candidate scheme; and obtaining candidate schemes according to a sequence of modulation format spectrum efficiency from high to low and spectrum window planes from front to back until available routes exist in the obtained candidate schemes, establishing an optical channel, and performing service transmission on the to-be-transmitted service. According to the method, different optical fibers are selected to establish the optical channels, spectrum allocation is more efficiently carried out, the utilization rate and flexibility of spectrum resources are improved, the influence caused by ultra-low loss optical fibers is fully considered, and under the situation of a hybrid optical fiber network, spectrum fragments are reduced, the network blocking rate is effectively reduced, and the network performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum allocation, and in particular to a spectrum allocation method and a readable storage medium applied to a hybrid optical fiber network. Background Art

[0002] In recent years, with the rapid development of new Internet services such as cloud computing / edge computing, the Internet of Things, and augmented reality / virtual reality, the demand for communication network bandwidth has exploded. These have brought severe challenges to the optical network that provides Internet bandwidth, and operators need to consider how to further improve the transmission bandwidth and efficiency of the backbone optical network. At present, the backbone optical network has transitioned from the traditional 100G and 200G standards to 400G, and has the potential to be further upgraded to 800G; however, with the increase in network transmission speed, the transmission performance and transmission distance have significantly decreased. To solve this problem, ultra-low loss (ULL) and large effective area optical fibers have been widely studied; this ULL optical fiber can significantly reduce signal attenuation and nonlinear effects, so it is expected to become the main optical fiber supporting 400G / 800G high-speed optical transmission systems. At present, China's three major domestic operators have begun to deploy this ULL optical fiber; however, considering cost factors, operators may continue to use existing standard single-mode optical fibers (SSMF) that have not exceeded their service life and "dark fibers" that have been installed but not yet used in the backbone network; therefore, the newly added ULL optical fiber into the existing SSMF network will form a hybrid optical fiber network.

[0003] At present, some studies have involved the optimization of spectrum resources in multi-fiber elastic optical networks under dynamic business scenarios. The team from the University of Washington proposed a routing and spectrum allocation scheme based on optimizing the state of multi-fiber EONs, and proved its effectiveness through simulation. The team from Osaka University proposed a dynamic RSA algorithm using multiple fibers for multi-domain EONs, which enhanced the statistical multiplexing effect of multiple fibers and effectively reduced the blocking probability. The team from the Indian Institute of Technology proposed a fragmentation sensing technology suitable for multi-core fiber space division multiplexing networks, which can effectively reduce the impact of fragmentation while keeping the damage caused by crosstalk within the threshold range. The team from Beijing University of Posts and Telecommunications and others proposed a routing, fiber core and spectrum allocation scheme, which significantly reduced the blocking probability and spectrum fragmentation of multi-core fiber space division multiplexing EONs by preferentially locating the core with higher transmission quality. However, the analysis of the above existing studies shows that the relevant teams have conducted extensive research on the optimization of spectrum resources in multi-fiber elastic optical networks under dynamic business scenarios, but these are mainly for the same type of fiber (SSMF) and do not consider the coexistence of different types of fibers.

[0004] In summary, the existing spectrum resource optimization methods for elastic optical networks are not applicable to hybrid fiber networks based on standard single-mode fiber and ultra-low loss fiber. In order to provide optical paths in hybrid fiber networks, in addition to traditional routing and spectrum allocation (RSA), it is also necessary to select suitable optical fibers between ULL fibers and SSMF on each link of the route, which increases the complexity of the optical path provisioning process and makes optimizing the network spectrum efficiency more challenging. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that spectrum resources cannot be optimized for a hybrid optical fiber network based on ultra-low loss optical fiber and standard single-mode optical fiber, which leads to a high system blocking rate.

[0006] In order to solve the above technical problems, the present invention provides a spectrum allocation method applied to a hybrid optical fiber network, comprising: S101: Obtain a source node, a destination node, a service flow rate, a service start time, a service end time, and a modulation format set of a service to be transmitted; S102: Obtain the modulation format with the highest spectrum efficiency in the modulation format set, take the number of frequency slots required by the service to be transmitted as the spectrum width, generate multiple spectrum windows under the modulation format based on the hybrid optical fiber network topology, and add the virtual links corresponding to the standard single-mode optical fiber with idle spectrum resources and the ultra-low loss optical fiber to the corresponding spectrum windows, and obtain multiple spectrum window planes under the modulation format; S103: according to the order of the spectrum window plane, using the Dijkstra algorithm, based on the physical distance of the virtual link, obtain the shortest path from the source node to the destination node of the service to be transmitted under the current spectrum window plane; S104: Based on the shortest path, generate multiple fiber selection schemes; the fiber selection schemes include selecting a standard single-mode fiber or an ultra-low-loss fiber for each link on the shortest path, and obtaining a fiber transmission path from a source node to a destination node of the service to be transmitted including the standard single-mode fiber and the ultra-low-loss fiber; S105: Deleting the optical fiber selection scheme whose optical signal-to-noise ratio cannot meet the optical signal-to-noise ratio threshold of the modulation format from the optical fiber selection scheme, to obtain multiple available optical fiber selection schemes; S106: Calculate the transmission cost corresponding to each available optical fiber selection scheme based on the available spectrum blocks, the number of adjacent spectrum changes, and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, and select the available optical fiber selection scheme with the largest transmission cost as the candidate scheme; determine whether the route of the candidate scheme is available: If available, an optical channel is established based on the candidate solution to transmit the service to be transmitted; If it is not available, return to step S103 to detect the next spectrum window plane in the modulation format until a candidate solution with available routing under the modulation format is obtained, and the service to be transmitted is transmitted; If there are no available routes for all spectrum window planes under the modulation format, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and the process returns to step S102 to detect the next modulation format in the updated modulation format set until a candidate solution with an available route is obtained, an optical channel is established, and the service to be transmitted is transmitted; If there are no available routes for all the modulation formats in the modulation format set, it is determined that service congestion occurs for the service to be transmitted.

[0007] Preferably, the modulation format set includes, in descending order based on spectrum efficiency, BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM.

[0008] Preferably, when acquiring the modulation format with the highest spectrum efficiency in the modulation format set, the method further includes: Sorting the modulation formats in the modulation format set in descending order of spectrum efficiency; Compare the modulation format with the highest spectrum efficiency with the number of frequency slots required for the service of the latter modulation format to see if they are the same: If they are not the same, proceed to step S102 based on the modulation format with the highest spectral efficiency; If they are the same, the modulation format with the highest spectrum efficiency is deleted from the modulation format set, and the process proceeds to step S102 based on the next modulation format.

[0009] Preferably, based on the service flow size of the service to be transmitted and the channel capacity of the modulation format, the number of frequency slots required for the service corresponding to the modulation format is calculated, which is expressed as: ; in, Indicates the number of frequency slots required for the service corresponding to the modulation format, Indicates the traffic size of the service to be transmitted. Indicates the channel capacity of the modulation format.

[0010] Preferably, the hybrid optical fiber network topology includes standard single mode optical fiber and ultra low loss optical fiber.

[0011] Preferably, based on the shortest path, the number of fiber selection solutions generated is the product of the number of links in the shortest path and the number of fiber categories in the hybrid fiber network.

[0012] Preferably, the construction of the spectrum window plane includes: Taking the number of frequency slots required by the services to be transmitted as the spectrum width, dividing the spectrum window for each link in the hybrid optical fiber network, and identifying the available spectrum window; Based on the available status of each spectrum window on each physical link, a spectrum window plane corresponding to each spectrum window is constructed, including: If in The first physical link If the available status of a spectrum window is available, add the first A physical link corresponds to a virtual link; If in The first physical link If the available status of a spectrum window is unavailable, the corresponding spectrum window plane does not exist. A physical link corresponds to a virtual link; A spectrum window plane is constructed based on virtual nodes corresponding to physical nodes in a hybrid optical fiber network, and virtual links corresponding to physical links.

[0013] Preferably, based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, the transmission cost corresponding to each available optical fiber selection scheme is calculated and expressed as: ; in, Indicates available fiber options The transmission cost, , represents a set of available fiber selection schemes; Indicates that the business traffic size that satisfies the business to be transmitted is Available fiber options The total number of available spectrum blocks, Indicates available fiber options The total number of adjacent spectrum state changes; Indicates the maximum number of adjacent spectrum state changes, the value is , Indicates the total number of frequency slots in the optical fiber; It is a preset weighting factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service.

[0014] Preferably, the value of the preset weight factor based on the type of optical fiber used in the available optical fiber selection scheme and the number of frequency slots required by the service includes: If the fiber selection solution only includes standard single-mode fiber, then the preset weight factor ; If the fiber selection options include standard single-mode fiber and ultra-low loss fiber, determine whether the number of frequency slots required for the services to be transmitted is reduced: If it decreases, then the preset weight factor ; If there is no reduction, then the preset weight factor .

[0015] This embodiment further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the spectrum allocation method applied to a hybrid optical fiber network as described above are implemented.

[0016] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The spectrum allocation method applied to a hybrid optical fiber network described in the present invention, when facing a hybrid optical fiber network including standard single-mode optical fiber and ultra-low loss optical fiber, constructs a spectrum window plane to select an available optical fiber selection scheme, can clearly obtain the available spectrum resources on each link in the hybrid optical fiber network, select different optical fibers to establish optical channels according to the spectrum usage of the link, and more efficiently perform spectrum allocation, thereby improving the utilization rate and flexibility of spectrum resources; for each available optical fiber selection scheme, the present invention calculates the corresponding transmission cost based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the optical fiber when transmitting the service to be transmitted; in ultra-low loss optical fiber, due to lower attenuation, the continuity and stability of spectrum resources are higher, and therefore the number of adjacent spectrum changes is less. The present invention fully considers the impact of ultra-low loss optical fiber to select candidate schemes for service transmission, and in the context of a hybrid optical fiber network, reduces spectrum fragmentation, effectively reduces the network blocking rate, and improves network performance.

[0017] When the present invention traverses the modulation formats in the modulation format set in order from high to low based on spectrum efficiency, if the number of frequency slots required for services of two adjacent modulation formats is the same, the modulation format with lower spectrum efficiency is selected for subsequent judgment; the modulation format with lower spectrum efficiency is preferentially selected, which can better adapt to changes in transmission conditions, improve the robustness of the network, and reserve more spectrum resources for future services, which helps to cope with the uncertainty of future business growth, ensure the sustainable development of the network, and improve network performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 It is a flowchart of the steps of the spectrum allocation method applied to the hybrid optical fiber network provided by the present invention; Figure 2It is a schematic diagram of spectrum window division; Figure 3 is a schematic diagram of the spectrum window plane; Figure 4 It is a schematic diagram of the frequency slot occupation status; Figure 5 It is a schematic diagram of the specific steps of dynamic routing spectrum allocation. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0020] Reference Figure 1 As shown, the flowchart of the spectrum allocation method applied to the hybrid optical fiber network provided by the present invention includes the following specific steps: S101: Obtain a source node, a destination node, a service flow rate, a service start time, a service end time, and a modulation format set of a service to be transmitted; S102: Obtain the modulation format with the highest spectrum efficiency in the modulation format set, take the number of frequency slots required by the service to be transmitted as the spectrum width, generate multiple spectrum windows under the modulation format based on the hybrid optical fiber network topology, and add the virtual links corresponding to the standard single-mode optical fiber with idle spectrum resources and the ultra-low loss optical fiber to the corresponding spectrum windows, and obtain multiple spectrum window planes under the modulation format; S103: according to the order of the spectrum window plane, using the Dijkstra algorithm, based on the physical distance of the virtual link, obtain the shortest path from the source node to the destination node of the service to be transmitted under the current spectrum window plane; S104: Based on the shortest path, generate multiple fiber selection schemes; the fiber selection schemes include selecting a standard single-mode fiber or an ultra-low-loss fiber for each link on the shortest path, and obtaining a fiber transmission path from a source node to a destination node of the service to be transmitted including the standard single-mode fiber and the ultra-low-loss fiber; S105: Deleting the optical fiber selection scheme whose optical signal-to-noise ratio cannot meet the optical signal-to-noise ratio threshold of the modulation format from the optical fiber selection scheme, to obtain multiple available optical fiber selection schemes; S106: Calculate the transmission cost corresponding to each available optical fiber selection scheme based on the available spectrum blocks, the number of adjacent spectrum changes, and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, and select the available optical fiber selection scheme with the largest transmission cost as the candidate scheme; determine whether the route of the candidate scheme is available: If available, an optical channel is established based on the candidate solution to transmit the service to be transmitted; If it is not available, return to step S103 to detect the next spectrum window plane in the modulation format until a candidate solution with available routing under the modulation format is obtained, and the service to be transmitted is transmitted; If there are no available routes for all spectrum window planes under the modulation format, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and the process returns to step S102 to detect the next modulation format in the updated modulation format set until a candidate solution with an available route is obtained, an optical channel is established, and the service to be transmitted is transmitted; If there are no available routes for all the modulation formats in the modulation format set, it is determined that service congestion occurs for the service to be transmitted.

[0021] Specifically, the modulation format set includes, in descending order based on spectrum efficiency, BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM.

[0022] In this embodiment, when obtaining the modulation format with the highest spectrum efficiency in the modulation format set, the method further includes: Sorting the modulation formats in the modulation format set in descending order of spectrum efficiency; Compare the modulation format with the highest spectrum efficiency with the number of frequency slots required for the service of the latter modulation format to see if they are the same: If they are not the same, proceed to step S102 based on the modulation format with the highest spectral efficiency; If they are the same, the modulation format with the highest spectrum efficiency is deleted from the modulation format set, and the process proceeds to step S102 based on the next modulation format.

[0023] When the present invention traverses the modulation formats in the modulation format set in order from high to low based on spectrum efficiency, if the number of frequency slots required for services of two adjacent modulation formats is the same, the modulation format with lower spectrum efficiency is selected for subsequent judgment; the modulation format with lower spectrum efficiency is preferentially selected, which can better adapt to changes in transmission conditions, improve the robustness of the network, and reserve more spectrum resources for future services, which helps to cope with the uncertainty of future business growth, ensure the sustainable development of the network, and improve network performance.

[0024] The embodiment of the present invention calculates the number of frequency slots required for the service corresponding to the modulation format based on the service flow size of the service to be transmitted and the channel capacity of the modulation format, which is expressed as: ;in, Indicates the number of frequency slots required for the service corresponding to the modulation format, Indicates the traffic size of the service to be transmitted. Indicates the channel capacity of the modulation format.

[0025] In the embodiment of the present invention, the hybrid fiber network topology includes standard single-mode fiber and ultra-low loss fiber; based on the shortest path, the number of fiber selection schemes generated is the product of the number of links in the shortest path and the number of fiber categories in the hybrid fiber network. That is, when there are 2 links in the shortest path, each path has two optical fibers to choose from, so there are 4 fiber selection schemes for the shortest path.

[0026] Specifically, the construction of the spectrum window plane in the embodiment of the present invention includes: Taking the number of frequency slots required by the services to be transmitted as the spectrum width, dividing the spectrum window for each link in the hybrid optical fiber network, and identifying the available spectrum window; Based on the available status of each spectrum window on each physical link, a spectrum window plane corresponding to each spectrum window is constructed, including: If in The first physical link If the available status of a spectrum window is available, add the first A physical link corresponds to a virtual link; If in The first physical link If the available status of a spectrum window is unavailable, the corresponding spectrum window plane does not exist. A physical link corresponds to a virtual link; A spectrum window plane is constructed based on virtual nodes corresponding to physical nodes in a hybrid optical fiber network, and virtual links corresponding to physical links.

[0027] Reference Figure 2 As shown, it is a schematic diagram of spectrum window division; refer to Figure 3 As shown in the figure, it is a schematic diagram of the spectrum window plane; at this time, the spectrum width is 3, so 12 frequency slots can construct 10 spectrum windows, namely SW1 to SW10; based on the physical structure of the hybrid optical fiber network, virtual nodes are added to the spectrum windows, and based on the occupancy of each spectrum window on each link, virtual links are added to the spectrum windows to construct the spectrum window plane corresponding to each spectrum window.

[0028] Specifically, based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, the transmission cost corresponding to each available optical fiber selection scheme is calculated and expressed as: ;in, Indicates available fiber options The transmission cost, , represents a set of available fiber selection schemes; Indicates that the business traffic size that satisfies the business to be transmitted is Available fiber options The total number of available spectrum blocks, Indicates available fiber options The total number of adjacent spectrum state changes; Indicates the maximum number of adjacent spectrum state changes, the value is , Indicates the total number of frequency slots in an optical fiber; refer to Figure 4 The figure shows the frequency slot occupancy status. The dark color indicates that the frequency slot is occupied. A continuous frequency slot in the spectrum that meets the number of frequency slots required by the service is called an available spectrum block. Based on the frequency slot occupancy status, if the number of frequency slots required by the service is 1, the available spectrum blocks are 3; if the number of frequency slots required by the service is 2, the available spectrum blocks are 2. The adjacent spectrum state change refers to whether the occupancy states of adjacent frequency slots are consistent. If they are consistent, the number of adjacent spectrum state changes is 0, otherwise it is 1. Figure 4 The total number of adjacent spectrum state changes in is 6; It is a preset weighting factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service.

[0029] The value of the preset weight factor includes: if the optical fiber selection scheme only includes standard single-mode optical fiber, then the preset weight factor If the optical fiber selection scheme includes standard single-mode optical fiber and ultra-low loss optical fiber, determine whether the number of frequency slots required for the service to be transmitted is reduced: if it is reduced, set the preset weight factor ; If there is no reduction, set the preset weight factor .

[0030] The present invention aims at the problem of spectrum resource optimization of hybrid optical fiber networks under dynamic business scenarios. It is based on reducing spectrum fragmentation, optimizing network performance, and reducing network blocking rate. A formula suitable for evaluating the spectrum fragmentation rate in hybrid optical fiber networks, namely, a transmission cost calculation formula, is proposed. According to this formula, appropriate optical fibers are dynamically selected to establish optical channels. The impact of ULL optical fibers is fully considered, and it can meet the needs of hybrid optical fiber network scenarios, thereby reducing spectrum fragmentation in the network and reducing blocking rate.

[0031] Based on the above embodiments, the embodiments of the present invention take the elastic optical network EON as the background, consider the coexistence of standard single-mode optical fiber SSMF and ultra-low loss ULL optical fiber, and study the problem of optimal allocation of spectrum resources in dynamic service scenarios. Figure 5 As shown in FIG. 1 , a schematic diagram of specific steps for dynamic routing spectrum allocation is shown. The specific optimization steps include: S201: Generate dynamic diversified business sequences; (s, d, r, t, e) is used to represent the service attributes, where s, d, r, t, and e represent the source node, destination node, traffic size, start time, and end time of the service, respectively. All data are randomly generated.

[0032] S202: Generate a list of spectrum window planes (SWPs); Traverse all modulation formats from high to low in terms of spectral efficiency: {BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM}; Referring to Table 1, the channel FS capacity and optical signal-to-noise ratio OSNR threshold under different modulation formats are shown; Table 1 Channel FS capacity and optical signal-to-noise ratio OSNR threshold under different modulation formats For each modulation format, the number of frequency slots (FSs) required is first calculated, and then compared with the number of frequency slots of the next modulation format; if the two are the same, it directly enters the next modulation format; Generate a spectrum window plane SWP according to the network topology, modulation format, and the number of frequency slots required by the service; In each SWP, virtual links corresponding to standard single-mode optical fibers and ultra-low-loss optical fibers with idle spectrum resources in the link are added into the plane; S203: Optical fiber selection strategy based on spectrum usage; Using Dijkstra algorithm, the shortest path R is found according to the physical distance of each virtual link in SWP; Generate a set of fiber selection schemes based on R , and remove fiber selection schemes where the optical signal-to-noise ratio (OSNR) fails to meet the modulation format threshold; According to the cost calculation formula, calculate the cost of each available optical fiber selection scheme, and select the scheme with the highest cost as the solution; The cost calculation formula is expressed as: , ; in, Defined as Fiber Selection Solution The larger the value of the fiber selection option, the more available spectrum capacity it has to meet the traffic demand. Indicates the use of optical fiber selection solution In order to meet the business flow , the total number of continuous idle spectrum blocks required along the route, that is, the total number of available spectrum blocks. Defined as when the fiber option is adopted The total number of adjacent spectrum state changes along the route, and Indicates the maximum number of adjacent spectrum state changes, and its fixed value is , is the total number of frequency slots in each optical fiber. is a weighting factor; if the fiber selection scheme If SSMF is used throughout the route, Set to 1; otherwise, if the fiber selection scheme If ULL fiber is used and it helps reduce the number of FSs required for the service, it is set to 1.2; otherwise, it is set to 0.8.

[0033] Finally, the algorithm selection cost The highest route carries the service. If the route exists, an optical channel is established; otherwise, the next SWP is traversed until all SWPs are traversed; if the route still does not exist at this time, the modulation format of the next level is considered until all modulation formats are traversed; if the route still does not exist at this time, the service is blocked.

[0034] Specifically, based on the above embodiment, the spectrum allocation method provided in this embodiment is evaluated based on the hybrid fiber network structure; each link in the hybrid fiber network structure network is composed of SSMF and ULL fiber; the network topology selects USNET, and the ULL fiber uses Corning TXF fiber, which is an ultra-low loss, large effective area ITU-T G.654.E fiber with a typical attenuation coefficient of 0.166dB / km, while the attenuation coefficient of SSMF is 0.20dB / km. Each fiber link has 320 FSs, the bandwidth granularity of each FS is 12.5GHz, and the placement distance of the optical amplifier (ie, EDFA) is equal and does not exceed 80 kilometers. Generate a dynamic service sequence, the total number of service requests in the network is fixed, which is 1380000, and the traffic of the service is randomly generated at [10,800]Gb / s. At the same time, it is assumed that the arrival of services in the optical network follows the Poisson distribution, and the Erlang value is the service load. The larger the value, the higher the service arrival rate, which varies from 2.4 to 3.6, with an interval of 0.2. According to the spectrum allocation method for hybrid optical fiber network provided in this embodiment, spectrum resources are allocated and services are transmitted; after all services are processed, the blocking rate of the network can be obtained and used as the performance indicator of the algorithm.

[0035] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the spectrum allocation method applied to a hybrid optical fiber network as described above are implemented.

[0036] The spectrum allocation method applied to a hybrid optical fiber network described in the present invention, when facing a hybrid optical fiber network including standard single-mode optical fiber and ultra-low loss optical fiber, constructs a spectrum window plane to select an available optical fiber selection scheme, can clearly obtain the available spectrum resources on each link in the hybrid optical fiber network, select different optical fibers to establish optical channels according to the spectrum usage of the link, and more efficiently perform spectrum allocation, thereby improving the utilization rate and flexibility of spectrum resources; for each available optical fiber selection scheme, the present invention calculates the corresponding transmission cost based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the optical fiber when transmitting the service to be transmitted; in ultra-low loss optical fiber, due to lower attenuation, the continuity and stability of spectrum resources are higher, and therefore the number of adjacent spectrum changes is less. The present invention fully considers the impact of ultra-low loss optical fiber to select candidate schemes for service transmission, and in the context of a hybrid optical fiber network, reduces spectrum fragmentation, effectively reduces the network blocking rate, and improves network performance. At the same time, when the present invention traverses the modulation formats in the modulation format set in order from high to low based on spectrum efficiency, if the number of frequency slots required for services of two adjacent modulation formats is the same, the modulation format with lower spectrum efficiency is selected for subsequent judgment; the modulation format with lower spectrum efficiency is preferentially selected, which can better adapt to changes in transmission conditions, improve the robustness of the network, and reserve more spectrum resources for future services, which helps to cope with the uncertainty of future business growth, ensure the sustainable development of the network, and improve network performance.

[0037] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0038] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0039] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0040] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0041] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A spectrum allocation method applied to a hybrid optical fiber network, characterized in that: include: S101: Obtain a source node, a destination node, a service flow rate, a service start time, a service end time, and a modulation format set of a service to be transmitted; S102: Obtain the modulation format with the highest spectrum efficiency in the modulation format set, take the number of frequency slots required by the service to be transmitted as the spectrum width, generate multiple spectrum windows under the modulation format based on the hybrid optical fiber network topology, and add the virtual links corresponding to the standard single-mode optical fiber with idle spectrum resources and the ultra-low loss optical fiber to the corresponding spectrum windows, and obtain multiple spectrum window planes under the modulation format; S103: according to the order of the spectrum window plane, using the Dijkstra algorithm, based on the physical distance of the virtual link, obtain the shortest path from the source node to the destination node of the service to be transmitted under the current spectrum window plane; S104: Based on the shortest path, generate multiple fiber selection schemes; the fiber selection schemes include selecting a standard single-mode fiber or an ultra-low-loss fiber for each link on the shortest path, and obtaining a fiber transmission path from a source node to a destination node of the service to be transmitted including the standard single-mode fiber and the ultra-low-loss fiber; S105: Deleting the optical fiber selection scheme whose optical signal-to-noise ratio cannot meet the optical signal-to-noise ratio threshold of the modulation format from the optical fiber selection scheme, to obtain multiple available optical fiber selection schemes; S106: Calculate the transmission cost corresponding to each available optical fiber selection scheme based on the available spectrum blocks, the number of adjacent spectrum changes, and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, and select the available optical fiber selection scheme with the largest transmission cost as the candidate scheme; determine whether the route of the candidate scheme is available: If available, an optical channel is established based on the candidate solution to transmit the service to be transmitted; If it is not available, return to step S103 to detect the next spectrum window plane in the modulation format until a candidate solution with available routing under the modulation format is obtained, and the service to be transmitted is transmitted; If there are no available routes for all spectrum window planes under the modulation format, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and the process returns to step S102 to detect the next modulation format in the updated modulation format set until a candidate solution with an available route is obtained, an optical channel is established, and the service to be transmitted is transmitted; If there are no available routes for all the modulation formats in the modulation format set, it is determined that service congestion occurs for the service to be transmitted.

2. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: The modulation format set includes BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM based on spectral efficiency from high to low.

3. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: When obtaining the modulation format with the highest spectrum efficiency in the modulation format set, it also includes: Sorting the modulation formats in the modulation format set in descending order of spectrum efficiency; Compare the modulation format with the highest spectrum efficiency with the number of frequency slots required for the service of the latter modulation format to see if they are the same: If they are not the same, proceed to step S102 based on the modulation format with the highest spectral efficiency; If they are the same, the modulation format with the highest spectrum efficiency is deleted from the modulation format set, and the process proceeds to step S102 based on the next modulation format.

4. The spectrum allocation method for hybrid optical fiber network according to claim 3, characterized in that: Based on the traffic volume of the service to be transmitted and the channel capacity of the modulation format, the number of frequency slots required for the service corresponding to the modulation format is calculated, which is expressed as: ； in, Indicates the number of frequency slots required for the service corresponding to the modulation format, Indicates the traffic size of the service to be transmitted. Indicates the channel capacity of the modulation format.

5. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: The hybrid fiber network topology includes standard single mode fiber and ultra low loss fiber.

6. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: Based on the shortest path, the number of fiber selection schemes generated is the product of the number of links in the shortest path and the number of fiber categories in the hybrid fiber network.

7. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: The construction of the spectrum window plane includes: Taking the number of frequency slots required by the services to be transmitted as the spectrum width, dividing the spectrum window for each link in the hybrid optical fiber network, and identifying the available spectrum window; Based on the available status of each spectrum window on each physical link, a spectrum window plane corresponding to each spectrum window is constructed, including: If in The first physical link If the available status of a spectrum window is available, add the first A physical link corresponds to a virtual link; If in The first physical link If the available status of a spectrum window is unavailable, the corresponding spectrum window plane does not exist. A physical link corresponds to a virtual link; A spectrum window plane is constructed based on virtual nodes corresponding to physical nodes in a hybrid optical fiber network, and virtual links corresponding to physical links.

8. The spectrum allocation method for hybrid optical fiber network according to claim 1, characterized in that: Based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the optical fiber when each available optical fiber selection scheme transmits the service to be transmitted, the transmission cost corresponding to each available optical fiber selection scheme is calculated and expressed as: ； in, Indicates available fiber options The transmission cost, , represents a set of available fiber selection schemes; Indicates that the business traffic size that satisfies the business to be transmitted is Available fiber options The total number of available spectrum blocks, Indicates available fiber options The total number of adjacent spectrum state changes; Indicates the maximum number of adjacent spectrum state changes, the value is , Indicates the total number of frequency slots in the optical fiber; It is a preset weighting factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service.

9. The spectrum allocation method for hybrid optical fiber network according to claim 8, characterized in that: The values ​​of the preset weighting factors based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service include: If the fiber selection solution only includes standard single-mode fiber, then the preset weight factor ; If the fiber selection options include standard single-mode fiber and ultra-low loss fiber, determine whether the number of frequency slots required for the services to be transmitted is reduced: If it decreases, then the preset weight factor ; If there is no reduction, then the preset weight factor .

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the spectrum allocation method applied to a hybrid optical fiber network as claimed in any one of claims 1 to 9 are implemented.

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