A spectrum allocation method applied to a hybrid fiber network and a readable storage medium

Abstract

The application relates to the technical field of spectrum allocation, and discloses a spectrum allocation method applied to a hybrid fiber network and a readable storage medium, which comprises the following steps: taking the required frequency slot number of a service to be transmitted as the spectrum width, constructing multiple spectrum window planes under a modulation format based on a hybrid fiber network topology, selecting a shortest path from the multiple spectrum window planes to construct a fiber selection scheme, calculating the transmission cost of the fiber selection scheme to select a candidate scheme, obtaining the candidate scheme in the order of the modulation format spectrum efficiency from high to low and the spectrum window plane from front to back, until there is an available route in the obtained candidate scheme, establishing an optical channel, and performing service transmission on the service to be transmitted. The application establishes the optical channel by selecting different fibers, more efficiently performs spectrum allocation, improves the utilization rate and flexibility of spectrum resources, fully considers the influence of the ultra-low-loss fiber, reduces spectrum fragmentation in the context of the hybrid fiber network, effectively reduces the network blocking rate, and improves the network performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spectrum allocation, and particularly relates to a spectrum allocation method applied to a hybrid fiber network and a readable storage medium. BACKGROUND

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

[0003] At present, some researches have involved the optimization of spectrum resources in multi-fiber elastic optical networks in dynamic service scenarios. A team from the University of Washington proposed a routing and spectrum allocation scheme based on the optimization of multi-fiber EON state, and proved its effectiveness through simulation. A team from Osaka University proposed a dynamic RSA algorithm for multi-domain EON that utilizes multi-fiber, which enhances the statistical multiplexing effect of multi-fiber and effectively reduces the blocking probability. A team from the Indian Institute of Technology proposed a fragmentation-aware 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 a threshold range. A team from the University of Post and Telecommunication, Beijing, proposed a routing, core and spectrum allocation scheme that significantly reduces the blocking probability and spectrum fragmentation of multi-core fiber space division multiplexing EON by preferentially positioning the core with higher transmission quality. However, by analyzing the foregoing existing researches, it can be found that the related teams have conducted extensive research on the optimization of spectrum resources in multi-fiber elastic optical networks in dynamic service scenarios, but these mainly target the same type of optical fiber (SSMF) and do not consider the coexistence of different types of optical fibers.

[0004] In summary, the existing elastic optical network spectrum resource optimization method is not applicable to the mixed fiber network based on standard single-mode fiber and ultra-low loss fiber; and to provide an optical path in the mixed fiber network, in addition to the traditional route and spectrum allocation (RSA), a suitable fiber must be selected between the ULL fiber and the SSMF on each link of the route, which increases the complexity of the optical path provisioning process and makes it more challenging to optimize network spectrum efficiency. SUMMARY

[0005] To this end, the technical problem to be solved by the present application is to overcome the problem that the prior art cannot optimize the spectrum resource of the mixed fiber network based on ultra-low loss fiber and standard single-mode fiber, thereby causing high system blocking rate.

[0006] To solve the above technical problems, the present application provides a spectrum allocation method applied to a mixed fiber network, comprising:

[0007] S101: obtaining the source node, destination node, traffic size, traffic start time, traffic end time and modulation format set of the to-be-transmitted service;

[0008] S102: obtaining the modulation format with the highest spectrum efficiency in the modulation format set, taking the number of frequency slots required by the to-be-transmitted service as the spectrum width, generating a plurality of spectrum windows under the modulation format based on the topology of the mixed fiber network, and adding the virtual links corresponding to the standard single-mode fiber and the ultra-low loss fiber with idle spectrum resources to the corresponding spectrum windows, and obtaining a plurality of spectrum window planes under the modulation format;

[0009] S103: according to the front and rear order of the spectrum window plane, using the Dijkstra algorithm, and based on the physical distance of the virtual link, obtaining the shortest path from the source node to the destination node of the to-be-transmitted service under the current spectrum window plane;

[0010] S104: generating a plurality of fiber selection schemes based on the shortest path; the fiber selection scheme includes selecting a standard single-mode fiber or an ultra-low loss fiber for each link on the shortest path to obtain a fiber transmission path from the source node to the destination node of the to-be-transmitted service including the standard single-mode fiber and the ultra-low loss fiber;

[0011] S105: deleting the fiber selection scheme in which the optical signal-to-noise ratio cannot meet the modulation format optical signal-to-noise ratio threshold in the fiber selection scheme, to obtain a plurality of available fiber selection schemes;

[0012] S106: based on the available spectrum blocks, the number of adjacent spectrum changes and the total frequency slot number of the optical fiber when transmitting the to-be-transmitted service according to each available optical fiber selection scheme, the transmission cost corresponding to each available optical fiber selection scheme is calculated, and the available optical fiber selection scheme with the maximum transmission cost is selected as the candidate scheme; it is judged whether the route of the candidate scheme is available:

[0013] If available, an optical channel is established based on the candidate scheme, and the to-be-transmitted service is transmitted;

[0014] If not available, return to step S103 to detect the next spectrum window plane in the modulation format until a candidate scheme with an available route under the modulation format is obtained, and the to-be-transmitted service is transmitted;

[0015] If all the spectrum window planes under the modulation format do not have available routes, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and step S102 is returned to detect the next modulation format in the updated modulation format set until a candidate scheme with an available route is obtained, an optical channel is established, and the to-be-transmitted service is transmitted;

[0016] If all the modulation formats in the modulation format set do not have available routes, it is determined that the to-be-transmitted service is blocked.

[0017] Preferably, the modulation formats in the modulation format set include, in order from high to low based on spectral efficiency: BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM.

[0018] Preferably, when the modulation format with the highest spectral efficiency in the modulation format set is obtained, it further includes:

[0019] The modulation formats in the modulation format set are sorted in order from high to low based on spectral efficiency;

[0020] It is compared whether the required frequency slot number of the service of the modulation format with the highest spectral efficiency and the next modulation format is the same:

[0021] If not the same, step S102 is entered based on the modulation format with the highest spectral efficiency;

[0022] If the same, the modulation format with the highest spectral efficiency is deleted from the modulation format set, and step S102 is entered based on the next modulation format.

[0023] Preferably, based on the service traffic size of the to-be-transmitted service and the channel capacity of the modulation format, the required frequency slot number of the service corresponding to the modulation format is calculated and represented as:

[0024] ;

[0025] wherein, represents the number of frequency slots required by the service corresponding to the modulation format, represents the traffic size of the service to be transmitted, represents the channel capacity of the modulation format.

[0026] Preferably, the hybrid fiber network topology comprises standard single-mode fiber and ultra-low-loss fiber.

[0027] Preferably, based on the shortest path, the number of generated fiber selection schemes is the product of the number of links in the shortest path and the number of fiber categories in the hybrid fiber network.

[0028] Preferably, the construction of the spectrum window plane comprises:

[0029] Divide each link in the hybrid fiber network into spectrum windows with the number of frequency slots required by the service to be transmitted as the spectrum width, and identify the available spectrum windows;

[0030] Based on the availability of each spectrum window on each physical link, construct a spectrum window plane corresponding to each spectrum window, comprising:

[0031] If the availability of the spectrum window on the physical link is available, add the corresponding virtual link of the physical link to the spectrum window plane; If the availability of the spectrum window on the physical link is not available, the corresponding virtual link of the physical link does not exist in the spectrum window plane;

[0032] If the availability of the spectrum window on the physical link is not available, the corresponding virtual link of the physical link does not exist in the spectrum window plane;

[0033] Based on the virtual nodes corresponding to the physical nodes in the hybrid fiber network and the virtual links corresponding to the physical links, construct the spectrum window plane.

[0034] Preferably, based on the available spectrum blocks, the number of adjacent spectrum changes and the total number of frequency slots of the fiber when transmitting the service to be transmitted based on each available fiber selection scheme, the transmission cost corresponding to each available fiber selection scheme is calculated, represented as:

[0035] ;

[0036] wherein, represents the transmission cost of the available fiber selection scheme , , represents the set of available fiber selection schemes; represents the traffic size of the service to be transmitted,​​​​​ available fiber selection scheme total number of available spectrum blocks, available fiber selection scheme total number of adjacent spectrum state changes; maximum number of adjacent spectrum state changes, taking a value of , total number of frequency slots in the fiber; preset weight factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service.

[0037] Preferably, the value of the preset weight factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service includes:

[0038] If the fiber selection scheme only includes standard single-mode fiber, the preset weight factor is set to ;

[0039] If the fiber selection scheme includes standard single-mode fiber and ultra-low-loss fiber, it is determined whether the number of frequency slots required by the service to be transmitted is reduced:

[0040] If yes, the preset weight factor is set to ;

[0041] If no, the preset weight factor is set to .

[0042] The embodiment also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the spectrum allocation method applied to the hybrid fiber network as described above.

[0043] The above technical solution of the present application has the following beneficial effects compared with the prior art:

[0044] The spectrum allocation method applied to the mixed optical fiber network provided by the application can clearly obtain the available spectrum resources on each link in the mixed optical fiber network when facing the mixed optical fiber network containing standard single-mode optical fiber and ultra-low-loss optical fiber, different optical fibers are selected to establish optical channels according to the spectrum usage of the link, spectrum allocation is more efficient, and the utilization rate and flexibility of spectrum resources are improved; for each available optical fiber selection scheme, the application calculates the corresponding transmission cost based on the available spectrum block when transmitting the to-be-transmitted service, the number of adjacent spectrum changes and the total frequency gap number of the optical fiber; in the ultra-low-loss optical fiber, the continuity and stability of the spectrum resources are higher due to the lower attenuation, and therefore the number of adjacent spectrum changes is less, the application fully considers the influence of the ultra-low-loss optical fiber to select the candidate scheme for service transmission, reduces the spectrum fragmentation in the context of the mixed optical fiber network, effectively reduces the network blocking rate, and improves the network performance.

[0045] When the modulation formats in the modulation format set are traversed in the order of spectrum efficiency from high to low, if the number of frequency gaps required by the services of the 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 the change of transmission conditions, improve the robustness of the network, and can reserve more spectrum resources for future services, which is helpful to cope with the uncertainty of future service growth, ensures the sustainable development of the network, and improves the network performance. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to make the content of the application more easily understood, the application will be further described in detail below according to the specific embodiments of the application and in combination with the drawings, in which:

[0047] Figure 1 is a step flow chart of the spectrum allocation method applied to the mixed optical fiber network provided by the application;

[0048] Figure 2 is a spectrum window division schematic diagram;

[0049] Figure 3 is a spectrum window plane schematic diagram;

[0050] Figure 4 is a frequency gap occupation state schematic diagram;

[0051] Figure 5 is a specific step schematic diagram of dynamic routing spectrum allocation. DETAILED DESCRIPTION

[0052] The application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the application and implement it, but the embodiments are not as limitations of the application.

[0053] Referring to Figure 1 The step flow chart of the spectrum allocation method applied to the hybrid fiber network provided by the application is shown in the figure, and the specific steps include:

[0054] S101: Obtain the source node, destination node, traffic size, service start time, service end time and modulation format set of the to-be-transmitted service;

[0055] S102: Obtain the modulation format with the highest spectrum efficiency in the modulation format set, take the number of frequency slots required by the to-be-transmitted service as the spectrum width, generate a plurality of spectrum windows under the modulation format based on the topology of the hybrid fiber network, and add the virtual links corresponding to the standard single-mode fiber and the ultra-low-loss fiber with idle spectrum resources to the corresponding spectrum window, and obtain a plurality of spectrum window planes under the modulation format;

[0056] S103: According to the front and rear order of the spectrum window plane, use the Dijkstra algorithm to obtain the shortest path from the source node to the destination node of the to-be-transmitted service under the current spectrum window plane based on the physical distance of the virtual link;

[0057] S104: Based on the shortest path, generate a plurality of fiber selection schemes; the fiber selection scheme includes selecting a standard single-mode fiber or an ultra-low-loss fiber for each link on the shortest path to obtain a fiber transmission path from the source node to the destination node of the to-be-transmitted service including the standard single-mode fiber and the ultra-low-loss fiber;

[0058] S105: Delete the fiber selection scheme in which the optical signal-to-noise ratio cannot meet the modulation format optical signal-to-noise ratio threshold in the fiber selection scheme, and obtain a plurality of available fiber selection schemes;

[0059] S106: Based on the available spectrum block, the number of adjacent spectrum changes and the total number of frequency slots of the fiber when transmitting the to-be-transmitted service under each available fiber selection scheme, calculate the transmission cost corresponding to each available fiber selection scheme, and select the available fiber selection scheme with the largest transmission cost as the candidate scheme; judge whether the route of the candidate scheme is available:

[0060] If available, establish an optical channel based on the candidate scheme to transmit the to-be-transmitted service;

[0061] If not available, return to step S103 to detect the next spectrum window plane in the modulation format until a candidate scheme with an available route under the modulation format is obtained to transmit the to-be-transmitted service;

[0062] If all the spectrum window planes under the modulation format do not have available routes, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and step S102 is returned to detect the next modulation format in the updated modulation format set until a candidate scheme with an available route is obtained, an optical channel is established, and the to-be-transmitted service is transmitted.

[0063] If all the modulation formats in the modulation format set do not have available routes, it is determined that the to-be-transmitted service is blocked.

[0064] Specifically, the modulation formats in the modulation format set include, in order from high to low based on spectral efficiency, BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM.

[0065] In the embodiment, when the modulation format with the highest spectral efficiency in the modulation format set is obtained, the following steps are further included:

[0066] The modulation formats in the modulation format set are sorted in order from high to low based on spectral efficiency;

[0067] It is compared whether the number of required frequency slots of the service of the modulation format with the highest spectral efficiency is the same as that of the next modulation format:

[0068] If not, step S102 is entered based on the modulation format with the highest spectral efficiency;

[0069] If yes, the modulation format with the highest spectral efficiency is deleted from the modulation format set, and step S102 is entered based on the next modulation format.

[0070] In the embodiment, when the modulation formats in the modulation format set are traversed in order from high to low based on spectral efficiency, if the number of required frequency slots of the services of two adjacent modulation formats is the same, the modulation format with lower spectral efficiency is selected for subsequent judgment; the modulation format with lower spectral efficiency is preferentially selected, which can better adapt to changes in transmission conditions, improve the robustness of the network, and can reserve more spectral resources for future services, which helps to cope with the uncertainty of future service growth, ensures the sustainable development of the network, and improves the network performance.

[0071] In the embodiment, the number of required frequency slots of the service corresponding to the modulation format is calculated based on the service traffic size of the to-be-transmitted service and the channel capacity of the modulation format, and is represented as: ; wherein, represents the number of required frequency slots of the service corresponding to the modulation format, represents the service traffic size of the to-be-transmitted service, represents the channel capacity of the modulation format.

[0072] In this embodiment of the invention, the hybrid optical fiber network topology includes standard single-mode optical fiber and ultra-low-loss optical 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 types in the hybrid optical fiber network. That is, when there are 2 links in the shortest path, each path has two types of optical fibers to choose from, so there are 4 fiber selection schemes for this shortest path.

[0073] Specifically, the construction of the spectral window plane in this embodiment of the invention includes:

[0074] Using the number of frequency slots required by the service to be transmitted as the spectrum width, the spectrum window is divided for each link in the hybrid fiber network, and the available spectrum window is identified.

[0075] Based on the availability status of each spectrum window on each physical link, construct the spectrum window plane corresponding to each spectrum window, including:

[0076] If in the 1st The first physical link If the availability status of the first spectral window is available, then add the first spectral window to the corresponding spectral window plane. Each physical link corresponds to a virtual link;

[0077] If in the 1st The first physical link If the available state of the first spectral window is unavailable, then the corresponding spectral window plane does not exist. Each physical link corresponds to a virtual link;

[0078] A spectrum window plane is constructed based on the virtual nodes corresponding to physical nodes and the virtual links corresponding to physical links in the hybrid fiber optic network.

[0079] Reference Figure 2 The diagram shown is a schematic of the spectrum window division; refer to... Figure 3 The diagram shows a schematic of the spectrum window plane. At this point, the spectrum width is 3, so 12 frequency slots can be used to construct 10 spectrum windows, namely SW1 to SW10. Based on the physical structure of the hybrid fiber network, virtual nodes are added to the spectrum windows. 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.

[0080] Specifically, based on the available spectrum blocks, the number of adjacent spectrum changes, and the total number of fiber slots for each available fiber selection scheme when transmitting the service to be transmitted, the transmission cost corresponding to each available fiber selection scheme is calculated and expressed as follows: ;in, Indicates available fiber optic selection schemes Transmission costs, , denotes a set of available fiber selection schemes; denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service , denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service Figure 4 denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service Figure 4 denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service denotes the total number of available fiber selection schemes satisfying the traffic size of the to-be-transmitted service

[0081] wherein the preset weight factor has a value including: if the fiber selection scheme only includes standard single-mode fiber, the preset weight factor is set as ; if the fiber selection scheme includes standard single-mode fiber and ultra-low-loss fiber, it is judged whether the traffic size of the to-be-transmitted service is reduced: if yes, the preset weight factor is set as ; if no, the preset weight factor is set as .

[0082] The present application is directed to the spectrum resource optimization problem of a hybrid fiber network in a dynamic service scenario, and is based on reducing spectrum fragmentation, optimizing network performance, and reducing network blocking rate. A formula suitable for evaluating the spectrum fragmentation rate in a hybrid fiber network is proposed, that is, a transmission cost calculation formula. According to the formula, a suitable fiber is dynamically selected to establish an optical channel, the influence of ULL fiber is fully considered, and the demand of a hybrid fiber network scenario can be met, so as to reduce spectrum fragmentation and reduce blocking rate in the network.

[0083] Based on the above embodiment, the embodiment of the present application takes the elastic optical network EON as the background, considers the coexistence of standard single-mode fiber SSMF and ultra-low-loss ULL fiber, and studies the optimization and distribution of spectrum resources in a dynamic service scenario. Referring to FIG. 6, it is a specific step diagram of dynamic routing spectrum allocation. The specific optimization steps include: Figure 5

[0084] ​S201: generating dynamic diverse traffic sequence;

[0085] Traffic attributes are characterized by (s, d, r, t, e), where s, d, r, t, e represent the source node, destination node, traffic size, traffic start time, and traffic end time of the traffic, respectively, and all data are randomly generated.

[0086] S202: generating a list of spectrum window planes (SWPs);

[0087] According to the spectrum efficiency, traverse all modulation formats from high to low: {BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM};

[0088] Referring to Table 1, the channel FS capacity and optical signal-to-noise ratio OSNR threshold under different modulation formats are shown.

[0089] Table 1 Channel FS capacity and optical signal-to-noise ratio OSNR threshold under different modulation formats

[0090] For each modulation format, first calculate the number of frequency slots (FSs) required, and then compare it with the number of frequency slots of the next modulation format; if they are the same, directly enter the next modulation format.

[0091] According to the network topology, modulation format, and the number of frequency slots required by the traffic, generate a spectrum window plane SWP.

[0092] In each SWP, add the virtual link corresponding to the standard single-mode fiber and the ultra-low-loss fiber with idle spectrum resources in the link to the plane.

[0093] S203: fiber selection strategy based on spectrum usage;

[0094] Using Dijkstra algorithm, find the shortest path R according to the physical distance of each virtual link in the SWP.

[0095] According to R, generate a set of fiber selection schemes , and delete the fiber selection schemes whose optical signal-to-noise ratio (OSNR) cannot meet the threshold of the modulation format.

[0096] According to the cost calculation formula, calculate the cost of each available fiber selection scheme, and select the scheme with the largest cost as the solution.

[0097] The cost calculation formula is represented as: , ;

[0098] wherein, is defined as the fiber selection scheme The higher the value of the fiber selection scheme, the more available spectrum capacity it has to meet traffic demand. Indicates the use of fiber optic selection scheme At that time, in order to meet business traffic The total number of consecutive free spectrum blocks required along the route, i.e., the total number of available spectrum blocks. Defined as when using fiber selection scheme The total number of adjacent spectrum state changes along the route, and This represents the maximum number of adjacent spectral state changes, and its value is fixed. , This represents the total number of frequency slots in each optical fiber. It is a weighting factor; if the fiber selection scheme If SSMF is used throughout the route, then... Set to 1; otherwise, if fiber selection scheme If using ULL fiber and it helps reduce the number of FSs required for the business, set it to 1.2; otherwise, set it to 0.8.

[0099] Finally, the cost of algorithm selection. The highest-level route carries the service. If the route exists, an optical channel is established; otherwise, the next SWP is traversed until all SWPs have been traversed. If the route still does not exist, the next-level modulation format is considered until all modulation formats have been traversed. If the route still does not exist, the service is blocked.

[0100] Specifically, based on the above-mentioned embodiments, the spectrum allocation method provided by the present embodiment is evaluated based on a hybrid fiber network structure; each link in the hybrid fiber network structure network is composed of SSMF and ULL fiber; the network topology is USNET, and the ULL fiber is selected as Corning TXF fiber, which is an ITU-T G.654.E fiber with ultra-low loss and large effective area, and the typical attenuation coefficient is 0.166 dB / km, while the attenuation coefficient of SSMF is 0.20 dB / km. Each fiber link has 320 FSs, the bandwidth granularity of each FS is 12.5 GHz, the placement distance of the optical amplifier (i.e. EDFA) is equal, and does not exceed 80 kilometers. A dynamic service sequence is generated, the total number of service requests in the network is fixed at 1380000, and the traffic of the service is randomly generated in [10, 800] Gb / s. At the same time, it is assumed that the arrival of the service in the optical network follows the Poisson distribution, the Erlang value is the service load, and the larger the value, the higher the service arrival rate, which varies from 2.4 to 3.6 with an interval of 0.2. The spectrum resource is allocated according to the spectrum allocation method applied to the hybrid fiber network provided by the present embodiment, and the service is transmitted; after the service is completely processed, the blocking rate of the network can be obtained, and the blocking rate is used as the performance indicator of the algorithm.

[0101] The present embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the spectrum allocation method applied to the hybrid fiber network.

[0102] The spectrum allocation method applied to the mixed optical fiber network can clearly obtain the available spectrum resources on each link in the mixed optical fiber network, select different optical fibers to establish optical channels according to the spectrum usage of the link, more efficiently perform spectrum allocation, and improve the utilization rate and flexibility of the spectrum resources; for each available optical fiber selection scheme, the application calculates the corresponding transmission cost based on the available spectrum block when transmitting the to-be-transmitted service, the number of adjacent spectrum changes, and the total frequency slot number of the optical fiber; in the ultra-low loss optical fiber, the continuity and stability of the spectrum resources are higher due to the lower attenuation, and therefore the number of adjacent spectrum changes is smaller; the application fully considers the influence of the ultra-low loss optical fiber to select a candidate scheme for service transmission, reduces the spectrum fragmentation in the context of the mixed optical fiber network, effectively reduces the network blocking rate, and improves the network performance. Meanwhile, when the modulation formats in the modulation format set are traversed in the order from high to low spectrum efficiency, if the required frequency slot numbers of the services of two adjacent modulation formats are the same, the modulation format with lower spectrum efficiency is selected for subsequent judgment; preferentially selecting the modulation format with lower spectrum efficiency can better adapt to the change of the transmission condition, improve the robustness of the network, and can reserve more spectrum resources for future services, which helps to cope with the uncertainty of future service growth, ensures the sustainable development of the network, and improves the network performance.

[0103] Those skilled in the art will understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0104] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems), and computer program products of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks.

[0105] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0107] Obviously, the above-described embodiments are only examples and are not intended to limit the present application. Based on the above description, one of ordinary skill in the art can make other variations and changes without departing from the present application. It is not necessary or possible to enumerate all the embodiments. The obvious variations and changes derived therefrom are still within the scope of the present application.

Claims

1. A method for spectrum allocation applied to a hybrid fiber network, characterized in that, The method comprises the following steps: S101: obtaining the source node, destination node, traffic size, traffic start time, traffic end time and modulation format set of the to-be-transmitted service; S102: obtaining the modulation format with the highest spectral efficiency in the modulation format set, taking the number of frequency slots required by the to-be-transmitted service as the spectral width, generating a plurality of spectral windows under the modulation format based on the topology of the hybrid fiber network, and adding the virtual links corresponding to the standard single-mode fiber and the ultra-low-loss fiber with idle spectrum resources to the corresponding spectral window to obtain a plurality of spectral window planes under the modulation format; S103: using the Dijkstra algorithm to obtain the shortest path from the source node to the destination node of the to-be-transmitted service under the current spectral window plane based on the physical distance of the virtual link in the order of the front and back of the spectral window plane; S104: generating a plurality of fiber selection schemes based on the shortest path, wherein the fiber selection scheme comprises selecting a standard single-mode fiber or an ultra-low-loss fiber for each link on the shortest path to obtain a fiber transmission path from the source node to the destination node of the to-be-transmitted service comprising a standard single-mode fiber and an ultra-low-loss fiber; S105: deleting the fiber selection scheme in which the optical signal-to-noise ratio cannot meet the modulation format optical signal-to-noise ratio threshold to obtain a plurality of available fiber selection schemes; S106: calculating the transmission cost corresponding to each available fiber selection scheme based on the available spectrum block, the number of adjacent spectrum changes and the total number of frequency slots of the fiber when transmitting the to-be-transmitted service under each available fiber selection scheme, and selecting the available fiber selection scheme with the largest transmission cost as the candidate scheme; judging whether the route of the candidate scheme is available: If available, an optical channel is established based on the candidate scheme to transmit the to-be-transmitted service; If not available, return to step S103 to detect the next spectral window plane in the modulation format until a candidate scheme with an available route under the modulation format is obtained to transmit the to-be-transmitted service; If there is no available route under all spectral window planes in the modulation format, the modulation format is deleted from the modulation format set, an updated modulation format set is obtained, and the next modulation format in the updated modulation format set is detected in step S102 until a candidate scheme with an available route is obtained to establish an optical channel and transmit the to-be-transmitted service; If there is no available route in all modulation formats in the modulation format set, it is determined that the to-be-transmitted service is blocked; The transmission cost corresponding to each available fiber selection scheme is represented as: ； wherein, denotes the transmission cost of the available fiber selection scheme , , denotes the set of available fiber selection schemes; denotes the available fiber selection scheme satisfying the service traffic size of the service to be transmitted , denotes the total number of available frequency spectrum blocks of the available fiber selection scheme , denotes the total number of adjacent frequency spectrum state changes of the available fiber selection scheme denotes the maximum number of adjacent frequency spectrum state changes, taking values from the set , denotes the total number of frequency slots in the fiber; is a preset weight factor based on the type of fiber used in the available fiber selection scheme and the number of frequency slots required by the service.

2. The spectrum allocation method for a hybrid fiber network according to claim 1, wherein, The modulation formats in the modulation format set include BPSK, QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM in the order from high to low based on spectral efficiency.

3. The spectrum allocation method for a hybrid fiber network of claim 1, wherein, When obtaining the modulation format with the highest spectral efficiency in the modulation format set, the following steps are further included: The modulation formats in the modulation format set are sorted in the order from high to low based on spectral efficiency; Comparing whether the number of frequency slots required by the service of the modulation format with the highest spectral efficiency and the next modulation format is the same: If not the same, enter step S102 based on the modulation format with the highest spectral efficiency; If the same, the highest spectral efficiency modulation format is removed from the modulation format set, and the latter modulation format is entered into step S102.

4. The spectrum allocation method for a hybrid fiber network according to claim 3, wherein, Based on the traffic size of the to-be-transmitted service and the channel capacity of the modulation format, the number of frequency slots required by the service corresponding to the modulation format is calculated, denoted as: ； wherein, represents the number of frequency slots required for a service corresponding to a modulation format, represents the traffic size of a service to be transmitted, represents the channel capacity of a modulation format.

5. The spectrum allocation method for a hybrid fiber network of claim 1, wherein, The hybrid fiber network topology includes standard single-mode fiber and ultra-low-loss fiber.

6. The method for spectrum allocation applied to a hybrid fiber network according to claim 1, wherein, Based on the shortest path, the number of generated fiber selection schemes 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 a hybrid fiber network of claim 1, wherein, The construction of the spectrum window plane includes: Divide each link in the hybrid fiber network into spectrum windows with the number of frequency slots required by the to-be-transmitted service as the spectrum width, and identify the available spectrum windows; Based on the available state of each spectrum window on each physical link, construct the spectrum window plane corresponding to each spectrum window, including: If the available state of the first frequency spectrum window on the first physical link is available, a virtual link corresponding to the first physical link is added to the corresponding frequency spectrum window plane. If in the 1st The first physical link If the available state of the first spectral window is unavailable, then the corresponding spectral window plane does not exist. Each physical link corresponds to a virtual link; Based on the virtual nodes corresponding to the physical nodes in the hybrid fiber network and the virtual links corresponding to the physical links, construct the spectrum window plane.

8. The method for spectrum allocation applied to a hybrid fiber network according to claim 1, wherein, Based on the preset weight factor values of the types of fibers used in the available fiber selection schemes and the number of frequency slots required by the service, including: If the fiber selection scheme only includes standard single-mode optical fiber, the preset weight factor ; If the fiber selection scheme includes standard single-mode fiber and ultra-low-loss fiber, determine whether the number of frequency slots required by the to-be-transmitted service is reduced: if the number of the selected images is reduced, the preset weight factor is set to be ; if not reduced, let the preset weight factor .

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the spectrum allocation method applied to the hybrid fiber network according to any one of claims 1 to 8. The computer program is executed by the processor to implement the steps of the spectrum allocation method applied to the hybrid fiber network according to any one of claims 1 to 8.

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