A method for resource allocation based on energy efficiency and crosstalk-fraction awareness in space division multiplexing elastic optical networks

Abstract

The application relates to a resource allocation method based on energy efficiency and crosstalk-fragmentation perception in a space division multiplexing elastic optical network, and belongs to the optical communication field. The method allocates transmission resources for services by considering the energy consumption, inter-core crosstalk and spectral fragmentation problems existing in the network. In the routing selection stage, a routing weight formula is designed in combination with link load and factors related to energy consumption equipment (link transmission distance, node degree, etc.), and a path with small energy consumption is preferentially selected; in the core selection stage, the cores are first grouped, and then a core selection weight formula is designed according to the accurate idle spectrum blocks and average available spectrum blocks in each core, and a core with a large weight value is preferentially selected; in the spectrum allocation stage, a spectrum block selection formula is designed in combination with the crosstalk degree and fragmentation degree, and the purpose is to balance the influence of crosstalk and fragmentation; finally, for the service request that fails to be successfully allocated, the service request is divided into two sub-services for transmission in a single core according to the proportion of idle spectrum resources in the partition, so that the use of fragmented resources is maximized while the use of guard bandwidth is minimized. The method can reduce energy consumption while guaranteeing the bandwidth blocking rate performance.

Description

Technical Field

[0001] This invention relates to the field of optical communication, and more specifically to a resource allocation method based on energy efficiency and crosstalk-fragment awareness in a spatially divided multiplexed elastic optical network. Background Technology

[0002] With the increasing prevalence of various network services, the overall internet traffic is growing rapidly, leading to an exponential increase in communication bandwidth each year. These massive data flows need to be transmitted through the optical fibers of the backbone network, creating a huge demand for bandwidth capacity. Traditional wavelength division multiplexing (WDM) optical communication systems rely on single-mode optical fibers, where optical signals are transmitted in parallel through non-overlapping, fixed-time-interval channels in the frequency domain. The granularity of bandwidth segmentation and allocation limited by the ITU's fixed-frequency grid limits results in a mismatch between allocated and requested link bandwidth. Furthermore, WDM networks cannot adaptively select modulation formats, making scalability difficult and hindering their ability to adapt to the future development needs of optical networks. Elastic Optical Networks (EONs) based on Orthogonal Frequency Division Multiplexing (OFDM) have become an excellent solution for efficiently allocating spectrum in the face of exponentially growing network traffic. However, due to the nonlinear Shannon limitation of traditional single-mode fibers (SMFs), their transmission capacity is approaching its limit. Therefore, Space Division Multiplexing Elastic Optical Networks (SDM-EONs) based on multi-fiber cores, proposed in recent years, can further solve the transmission capacity problem and are currently the most promising development direction.

[0003] However, introducing spatial dimension into SDM-EONs presents three challenges for service transmission: First, services must meet three constraints during spectrum allocation, leading to discontinuous distribution of available spectrum resources within fiber cores and exacerbating spectrum fragmentation. Second, to increase transmission capacity, SDM-EONs employ multi-core fibers; overlapping frequency slots between adjacent cores can cause inter-core crosstalk, impacting service transmission quality. Third, to ensure normal service transmission, numerous energy-intensive devices operate, especially in SDM-EONs where a large number of services are transmitted simultaneously across multiple fiber cores, exacerbating energy consumption issues. Therefore, in spatially multiplexed elastic optical networks, reducing spectrum fragmentation, inter-core crosstalk, and energy consumption to ensure low bandwidth blocking rates while simultaneously lowering energy consumption is crucial. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a resource allocation method based on energy efficiency and crosstalk-fragmentation awareness in a spatially divided multiplexed elastic optical network, with the aim of reducing energy consumption while ensuring a low bandwidth blocking rate.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A resource allocation method based on energy efficiency and crosstalk-fragment awareness in a spatially multiplexed elastic optical network, the specific steps of which are as follows:

[0007] S1: For incoming services, design a link weight formula based on link load and energy consumption-related factors, calculate the weight value of each link, and select the candidate path set K in ascending order according to the principle of the shortest path algorithm based on the size of the link weight value. Then, sort the candidate paths in K in ascending order according to their transmission distance and select the best transmission path in turn.

[0008] The link weight formula is as follows:

[0009]

[0010] In the link weight formula, LBE (u,v) The link weight is represented by |O|, |F|, and |V|, which represent the number of fiber cores, the number of frequency slots on each link, and the total number of nodes, respectively. It is a binary variable; its value is 0 when the fiber core slot 0 is not occupied, and 1 otherwise. u d represents the degree of node u in the link (u,v). (u,v) This represents the transmission distance of the link (u,v).

[0011] S2: Based on the candidate path length, determine the service modulation level and the number of frequency slots required for the service. Then, according to the predefined fiber core grouping, group the non-adjacent fiber cores into a group, and the group set is G. Taking a seven-core fiber as an example, group the non-adjacent fiber cores 1, 2, and 3 into a group, which is represented as G1. Group the fiber cores 4, 5, and 6 into a group, which is represented as G2. The remaining fiber core 7 does not participate in the grouping and is set as a common fiber core.

[0012] S3: Based on the number of precisely available free spectrum blocks (spectrum blocks with the number of frequency slots equal to the number of frequency slots required by the service) and the average size of available free spectrum blocks on each fiber core in the group, design the fiber core weight formula, calculate the weight value of each fiber core in the group, and sort the fiber cores of the group in descending order according to the weight value of the fiber core in set O.

[0013] The formula for core weighting is as follows:

[0014]

[0015] In the fiber core weight formula, W oIndicates the weight of the fiber core o; EG o Represents the precise set of free spectrum blocks in fiber core o; |EG o | Indicates the precise number of free spectrum blocks in fiber core o; VG o Represents the set of available free spectrum blocks in fiber core o; |VG o | Indicates the number of available free spectrum blocks in fiber core o; gap i VG o The size of the i-th available free spectrum block.

[0016] S4: Based on the crosstalk calculation formula, count the available idle spectrum blocks in the current fiber core o;

[0017] The formula for calculating inter-core crosstalk is as follows:

[0018]

[0019]

[0020] In the formula for calculating inter-core crosstalk, XT oo′ This represents the crosstalk value between fiber cores o and o′ due to occupying the same frequency slot; o represents the working fiber core; o′ represents the adjacent fiber core of o; n represents the number of adjacent fiber cores; L represents the transmission distance; h represents the crosstalk increment per unit length. Where k, r, β, and ω represent the coupling coefficient, bending radius, propagation coefficient, and fiber core spacing, respectively; XT o N represents the total crosstalk value generated by fiber core o and all its adjacent fiber cores; o This represents the set of adjacent fiber cores of fiber core o.

[0021] S5: Enumerate all allocation methods with a fixed frequency slot interval, and count the selected spectrum blocks under each service allocation method. Add them to set A. Then, consider the crosstalk and fragmentation levels under different allocation methods to select the best allocation method. Calculate the crosstalk-fragmentation level metric for each spectrum block in set A in turn. Sort the available idle spectrum blocks in set A in descending order according to the weight of each spectrum block.

[0022] S6: For services that fail to be allocated in all candidate paths, divide them into two sub-services according to the proportion of idle spectrum resources in the partition.

[0023] Furthermore, S5 is specifically implemented in the following ways:

[0024] S501: Enumerate all allocation methods using a fixed frequency slot interval, where the fixed frequency slot interval is set to the number of frequency slots required by the service. If the current available free spectrum block size is a multiple of the number of frequency slots required by the service, then traverse in ascending order starting from the starting frequency slot of the available free spectrum block using the fixed frequency slot interval. If the current available spectrum block size is not a multiple of the number of frequency slots required by the service, then traverse in ascending order once starting from the starting frequency slot of the available spectrum block using the fixed frequency slot interval, and traverse in reverse order once starting from the ending frequency slot of the available spectrum block. Count the spectrum blocks selected under each service allocation method and add them to set A.

[0025] S502: After determining all allocation methods, the crosstalk level measurement value of each spectrum block in set A will be calculated according to the crosstalk level measurement formula.

[0026] The formula for measuring crosstalk level is as follows:

[0027]

[0028]

[0029] In the crosstalk measurement formula, DCT o The value represents the crosstalk of fiber core o, which is the accumulated empty frequency slots on adjacent fiber cores of fiber core o in link l within the frequency slot index range; begin and end represent the start and end index values ​​of the frequency slot index range, respectively; l represents the link in the selected path; PL represents the set of links in the selected path; AO represents the set of adjacent fiber cores of fiber core o in link l. It is a binary variable; its value is 1 when slot f in fiber core ao is not occupied, and 0 otherwise; XT so SAO represents the cumulative crosstalk value of adjacent cores of core so; SAO represents the set of adjacent cores of core so; o represents the adjacent cores of so.

[0030] S503: Calculate the fragmentation degree measure value of each spectrum block in set A based on the fragmentation degree measure formula;

[0031] The formula for measuring the degree of fragmentation is as follows:

[0032]

[0033] In the fragmentation degree measurement formula, MUG represents the cumulative value of the frequency slots occupied in all links within the index range; L represents the total set of links; This indicates the slot occupancy status in link l. The value is 0 when slot f is not occupied, and 1 otherwise.

[0034] S504: Calculate the crosstalk-fragmentation metric value for each spectral block in set A based on the crosstalk-fragmentation metric formula;

[0035] The formula for measuring crosstalk-fragmentation is as follows:

[0036] CFB=XT so +MUG

[0037] In the crosstalk-fragmentation metric formula, CFB represents the sum of crosstalk and fragmentation within the index range, and the spectrum block with the smallest CFB value in set A will be selected for transmission.

[0038] Furthermore, S6 is specifically implemented in the following ways:

[0039] S601: The service segmentation strategy divides the spectrum resources in the fiber core into two partitions, namely partition I and partition II. Initially, each of the two partitions occupies half of the spectrum resources in the fiber core.

[0040] S602: By considering the proportion of idle spectrum resources in the partition, design a service segmentation formula, calculate the required number of frequency slots for sub-service 1 and sub-service 2 according to the service segmentation formula. If partition I (partition II) does not have enough spectrum resources for sub-service 1 (2) to allocate, then consider shifting the range of partition I (partition II) to the right (left) by the number of frequency slots required by the sub-service.

[0041] The business segmentation formula is as follows:

[0042]

[0043] FS2 = FS - FS1

[0044] In the service segmentation formula, FS1 and FS2 represent the required number of frequency slots for sub-service 1 and sub-service 2, respectively; begin p1 and end p1 These represent the start and end frequency slot index values ​​for partition I, respectively; begin p2 and end p2 These represent the start and end frequency slot index values ​​for partition II, respectively. and 0 represents the occupancy status of the i-th frequency slot in partition I and the occupancy status of the i-th frequency slot in partition II, respectively. If the frequency slot is occupied, it is 0; otherwise, it is 1. FS represents the number of frequency slots required by the service.

[0045] S603: If there are available spectrum blocks in partition I and partition II, sub-service 1 and sub-service 2 will be allocated in partition I and partition II respectively in the manner of first matching. Otherwise, if no matter how the partition range is moved, only one sub-service can be allocated, or if there are not enough spectrum resources in the two partitions for the sub-service to be allocated, then the service segmentation will fail.

[0046] The beneficial effects of this invention are as follows: This invention provides a resource allocation method based on energy efficiency and crosstalk-fragmentation awareness in a spatially divided multiplexing elastic optical network. When allocating spectrum resources for services, it considers spectrum fragmentation, inter-core crosstalk, and energy consumption. In the routing phase, the algorithm designs a routing weight formula based on factors related to link load and energy-consuming devices, selecting candidate paths in ascending order of path weights, prioritizing paths with low energy consumption. In the fiber core selection phase, it designs a fiber core selection weight formula mainly based on the precise idle spectrum blocks and average available spectrum blocks in each fiber core, prioritizing fiber cores with larger weights in the group. In the spectrum allocation phase, to balance crosstalk and fragmentation issues, it selects the optimal idle spectrum block by measuring the degree of crosstalk and fragmentation. Finally, for service requests that fail to transmit successfully, they are divided into two sub-services according to the proportion of idle spectrum resources in the partition. By limiting the number of divisions, the success rate of service transmission is improved while reducing the use of protection bandwidth.

[0047] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0048] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0049] Figure 1 The overall flowchart of the resource allocation method based on energy efficiency and crosstalk-fragmentation awareness in the space-division multiplexing elastic optical network proposed in this invention;

[0050] Figure 2 Example diagram of spectrum block selection used in this invention;

[0051] Figure 3 Example diagram of crosstalk-fragmentation metric used in this invention;

[0052] Figure 4 The business segmentation example diagram used in this invention. Detailed Implementation Plan

[0053] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0054] Appendix Figure 1 The following is a flowchart of the resource allocation method based on energy efficiency and crosstalk-fragment awareness in a spatially divided multiplexing elastic optical network, which will be explained in detail below:

[0055] Input: Optical network topology G(V,E,O,F), service request r i =(s i ,d i B r )

[0056] Output: Service transmission results

[0057] Step 1: Initialize the network topology, candidate path set K=Φ, group set G=Φ, fiber core set O=Φ, intra-group fiber core set GO=Φ, spectrum block set A=Φ, and predefine the groups;

[0058] Step 2: When the service arrives, select the candidate path set K in ascending order according to the value calculated by formula (1), and sort the candidate path set K in ascending order according to its transmission distance. Traverse all candidate paths, and set the initial path number as k = 1 and the number of candidate paths as |K|.

[0059]

[0060] In formula (1), LBE (u,v) The link weight is represented by |O|, |F|, and |V|, which represent the number of fiber cores, the number of frequency slots on each link, and the total number of nodes, respectively. It is a binary variable; its value is 0 when the fiber core slot 0 is not occupied, and 1 otherwise. u d represents the degree of node u in the link (u,v). (u,v) This represents the transmission distance of the link (u,v).

[0061] Step 3: Based on the candidate path length, determine the modulation level of the service and the required number of frequency slots FS, update the packet set G, traverse all packets, and set the initial packet number as g = 1, and the total number of packets as |G|.

[0062] Step 4: Update the set of fiber cores GO in the group. Calculate the weight value of the fiber cores in the group according to formula (2), and sort the fiber cores in the group in descending order according to the weight value. Traverse all fiber cores in the group. Let the initial fiber core number be c=1 and the number of fiber cores in the group be |GO|.

[0063]

[0064] In formula (2), W o Indicates the weight of the fiber core o; EG o Represents the precise set of free spectrum blocks in fiber core o; |EG o | Indicates the precise number of free spectrum blocks in fiber core o; VG o Represents the set of available free spectrum blocks in fiber core o; |VG o | Indicates the number of available free spectrum blocks in fiber core o; gapi VG o The size of the i-th available free spectrum block.

[0065] Step 5: Calculate the crosstalk value of each frequency slot according to formula (3) and formula (4), and determine whether there is an available idle spectrum block that meets the crosstalk threshold. The crosstalk threshold is -16dB. If it does not exist, go to step 7; otherwise, go to step 6.

[0066] The formula for calculating inter-core crosstalk is as follows:

[0067]

[0068]

[0069] In formulas (3)-(4), XToo′ represents the crosstalk value between fiber cores o and o′ due to occupying the same frequency slot; o represents the working fiber core; o′ represents the adjacent fiber core of o; n represents the number of adjacent fiber cores; L represents the length of the transmission distance; h represents the crosstalk increment per unit length. Where k, r, β, and ω represent the coupling coefficient, bending radius, propagation coefficient, and fiber core spacing, respectively; XTo represents the total crosstalk value generated by fiber core o and all its adjacent fiber cores; and No represents the set of adjacent fiber cores of fiber core o.

[0070] Step 6: Count the spectrum blocks selected under each service allocation method in fiber core o and add them to the spectrum block set A. Then sort the spectrum block set A in descending order according to formula (5), select the idle spectrum block with the largest value to transmit the service, and the service transmission is successful.

[0071]

[0072]

[0073]

[0074] CFB=XT s o+MUG(8)

[0075] In formulas (5)-(8), DCTo represents the crosstalk of fiber core o, and its value is the accumulated empty frequency slot on the adjacent fiber cores of fiber core o in link l within the frequency slot index value range; begin and end represent the start index value and end index value of the frequency slot index value range, respectively; l represents the link in the selected path; PL represents the set of links in the selected path; AO represents the set of adjacent fiber cores of fiber core o in link l; It is a binary variable; its value is 1 when slot f in fiber core ao is not occupied, and 0 otherwise; XT so represents the cumulative crosstalk value of adjacent fiber cores of fiber core so; SAO represents the set of adjacent fiber cores of fiber core so; o represents the adjacent fiber cores of so; MUG represents the cumulative value of occupied frequency slots in all links within the index range; L represents the total set of links; The value indicates the frequency slot occupancy status in link l. When slot f is not occupied, the value is 0, otherwise it is 1. CFB represents the sum of crosstalk and fragmentation within the index range. The spectrum block with the smallest CFB value in set A will be selected to transmit the service.

[0076] Step 7: o = o + 1, is o greater than |GO|? If it is, go to step 8; otherwise, go to step 6.

[0077] Step 8: g = g + 1, is g greater than |G|? If it is, go to step 9; otherwise, go to step 4.

[0078] Step 9: Determine whether there are available free spectrum blocks in the common fiber core that meet the crosstalk threshold. If they exist, allocate spectrum in the fiber core according to the FF method, and the service transmission will be successful. Otherwise, proceed to step 10.

[0079] Step 10: k = k + 1, is k greater than |K|? If it is, go to step 11; otherwise, go to step 3.

[0080] Step 11: Let k = 1, traverse all fiber cores, initialize the fiber core number o = 1, and the total number of fiber cores is |O|;

[0081] Step 12: Divide the spectrum resources in fiber core o into partition I and partition II on an average basis;

[0082] Step 13: Calculate the number of frequency slots required for the sub-service according to formula (9) and formula (10). The number of frequency slots required for sub-service 1 is represented as FS1, and the number of frequency slots required for sub-service 2 is represented as FS2. Then determine whether there are no available idle spectrum blocks that meet the crosstalk threshold in partition I and partition II. If there are none, proceed to step 16; otherwise, proceed to step 14.

[0083]

[0084] FS2 = FS - FS1 (10)

[0085] In formulas (9)-(10), FS1 and FS2 represent the required number of frequency slots for sub-service 1 and sub-service 2, respectively; begin p1 and end p1 These represent the start and end frequency slot index values ​​for partition I, respectively; begin p2 and end p2 These represent the start and end frequency slot index values ​​for partition II, respectively. and 0 represents the occupancy status of the i-th frequency slot in partition I and the occupancy status of the i-th frequency slot in partition II, respectively. If the frequency slot is occupied, it is 0; otherwise, it is 1. FS represents the number of frequency slots required by the service.

[0086] Step 14: Determine whether there are any available free spectrum blocks in partition I that meet the crosstalk threshold. If not, shift the range of partition I to the right by FS1 slot units and go to step 13; otherwise, go to step 15.

[0087] Step 15: Determine if there are any available free spectrum blocks in partition II that meet the crosstalk threshold. If not, shift the range of partition II to the left by FS2 slot units and proceed to step 13. Otherwise, the service transmission is successful.

[0088] Step 16: o = o + 1, is o greater than |O|? If it is, the service is blocked; otherwise, go to step 12.

[0089] Appendix Figure 2 Example diagram for spectrum block selection: For a service request requiring 4 slots, there are two available spectrum blocks in the path for the current service to allocate. The size of the first available spectrum block is 8, the fixed slot interval is 4, and the size of the available spectrum block is a multiple of the number of slots required by the service. The possible allocation methods and the corresponding slot index value ranges are as follows: forward sequence 1: [1, 4]; forward sequence 2: [5, 8]. The size of the second available spectrum block is 11, which is not a multiple of the number of slots required by the service. The possible allocation methods and the corresponding slot index value ranges are as follows: forward sequence 1: [15, 18]; forward sequence 2: [19, 22]; reverse sequence 3: [22, 25]; reverse sequence 4: [18, 21].

[0090] Appendix Figure 3For example, consider the crosstalk-fragmentation metric diagram. Assume a service R(1,2,4) arrives, where 1, 2, and 4 represent the source node, destination node, and required number of frequency slots, respectively. The transmission path is selected as 1→2, and the spectrum resources in fiber core 4 are selected for service allocation. As can be seen from the diagram, the size of the spectrum block in fiber core 4 is 6, which is not a multiple of the number of frequency slots required by the service. Therefore, a fixed frequency slot interval of 4 is used, and an ascending and descending traversal method is adopted to select an idle spectrum block. There are a total of 2 spectrum blocks available for service allocation, namely ascending order 1: [2,5] and descending order 2: [4,7]. If the service is allocated to the first idle spectrum block, firstly, according to formula (5), the crosstalk levels of the adjacent fiber cores of fiber core 4 are 9, 12, and 6 respectively. According to formula (6), the crosstalk level value is 27. Secondly, within the frequency slot index range of the idle spectrum block, according to formula (7), the occupied frequency slots in all links are accumulated, and the fragmentation level value is 15. Finally, according to formula (8), the crosstalk-fragmentation level value is 42. Similarly, if the service is allocated to the second idle spectrum block, the crosstalk level value is 28, the fragmentation level value is 12, and the crosstalk-fragmentation level value is 40. By comparing the crosstalk-fragmentation level values ​​of the two idle spectrum blocks, the idle spectrum block with a frequency slot index range of [2, 5] will be selected for service allocation.

[0091] Appendix Figure 4 For example, when a service with a required number of frequency slots FS=5 arrives, since there are no sufficiently large free spectrum blocks in the path for the service to allocate, the service needs to be segmented. First, the spectrum resources are divided into partition I and partition II. Then, the service is segmented according to formulas (9) and (10), and FS1=2 and FS2=3 can be calculated. Figure 4 As shown in (a), there are not enough free spectrum blocks in partition I to allocate to sub-service 1. Therefore, the range of partition I is shifted to the right by 2 units. According to the formula, the number of frequency slots required by the sub-service is updated to FS1=3 and FS2=2. At this time, the free spectrum blocks with frequency slot index values ​​of [10, 12] and [17, 18] in the path can be allocated to the two sub-services.

[0092] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A resource allocation method based on energy efficiency and crosstalk-fragmentation awareness in a spatially divided multiplexing elastic optical network, characterized in that, The method specifically includes the following steps: S1: For incoming services, design a link weight formula based on link load and energy consumption-related factors, calculate the weight value of each link, and select the candidate path set K in ascending order according to the principle of the shortest path algorithm based on the size of the link weight value. Then, sort the candidate paths in K in ascending order according to their transmission distance and select the best transmission path in turn. The link weight formula is as follows: In the link weight formula, LBE (u,v) The link weight is represented by |O|, |F|, and |V|, which represent the number of fiber cores, the number of frequency slots on each link, and the total number of nodes, respectively. It is a binary variable; its value is 0 when the fiber core slot 0 is not occupied, and 1 otherwise. u d represents the degree of node u in the link (u,v). (u,v) This represents the transmission distance of the link (u,v); S2: Based on the candidate path length, determine the service modulation level and the number of frequency slots required for the service. Then, according to the predefined fiber core grouping, group the non-adjacent fiber cores into a group, and the group set is G. Taking a seven-core fiber as an example, group the non-adjacent fiber cores 1, 2, and 3 into a group, which is represented as G1. Group the fiber cores 4, 5, and 6 into a group, which is represented as G2. The remaining fiber core 7 does not participate in the grouping and is set as a common fiber core. S3: Based on the number of precisely available free spectrum blocks (spectrum blocks with the number of frequency slots equal to the number of frequency slots required by the service) and the average size of available free spectrum blocks on each fiber core in the group, design the fiber core weight formula, calculate the weight value of each fiber core in the group, and sort the fiber cores of the group in descending order according to the weight value of the fiber core in set O. The formula for core weighting is as follows: In the fiber core weight formula, W o Indicates the weight of the fiber core o; EG o Represents the set of precisely free spectrum blocks in fiber core o; |EG o | Indicates the precise number of free spectrum blocks in fiber core o; VG o Represents the set of available free spectrum blocks in fiber core o; |VG o | Indicates the number of available free spectrum blocks in fiber core o; gap i VG o The size of the i-th available free spectrum block; S4: Based on the crosstalk calculation formula, count the available idle spectrum blocks in the current fiber core o; The formula for calculating inter-core crosstalk is as follows: In the formula for calculating inter-core crosstalk, XT oo′ This represents the crosstalk value between fiber cores o and o′ due to occupying the same frequency slot; o represents the working fiber core; o′ represents the adjacent fiber core of o; n represents the number of adjacent fiber cores; L represents the transmission distance; h represents the crosstalk increment per unit length. Where k, r, β, and ω represent the coupling coefficient, bending radius, propagation coefficient, and fiber core spacing, respectively; XT o N represents the total crosstalk value generated by fiber core o and all its adjacent fiber cores; o This represents the set of adjacent cores of core o; S5: Enumerate all allocation methods with a fixed frequency slot interval, and count the selected spectrum blocks under each service allocation method. Add them to set A. Then, consider the crosstalk and fragmentation levels under different allocation methods to select the best allocation method. Calculate the crosstalk-fragmentation level metric for each spectrum block in set A in turn. Sort the available idle spectrum blocks in set A in descending order according to the weight of each spectrum block. S6: For services that fail to be allocated in all candidate paths, a service segmentation strategy will be further considered to divide the service into two sub-services. To reasonably segment the service, firstly, the service segmentation strategy divides the spectrum resources in the fiber core into two partitions, namely partition I and partition II. Initially, the two partitions occupy half of the spectrum resources in the fiber core. Then, by considering the proportion of idle spectrum resources in the partitions, a service segmentation formula is designed. The required number of frequency slots for sub-service 1 and sub-service 2 is calculated according to the service segmentation formula. If partition I (partition II) does not have enough spectrum resources for sub-service 1 (2) to be allocated, then the range of partition I (partition II) is shifted to the right (left) by the number of frequency slots required by the sub-service. Finally, if there are available spectrum blocks in partition I and partition II, then sub-service 1 and sub-service 2 are allocated in partition I and partition II respectively in the first matching manner. Otherwise, if no matter how the partition range is moved, only one sub-service can be allocated, or if there are not enough spectrum resources in the two partitions for their sub-services to be allocated, then the service segmentation fails. The business segmentation formula is as follows: FS2 = FS - FS1 In the service segmentation formula, FS1 and FS2 represent the required number of frequency slots for sub-service 1 and sub-service 2, respectively; begin p1 and end p1 These represent the start and end frequency slot index values ​​for partition I, respectively; begin p2 and end p2 These represent the start and end frequency slot index values ​​for partition II, respectively. and 0 represents the occupancy status of the i-th frequency slot in partition I and the occupancy status of the i-th frequency slot in partition II, respectively. If the frequency slot is occupied, it is 0; otherwise, it is 1. FS represents the number of frequency slots required by the service.

2. The resource allocation method based on energy efficiency and crosstalk-fragmentation awareness in a spatially divided multiplexing elastic optical network according to claim 1, characterized in that: The specific method of S5 is as follows: S501: Enumerate all allocation methods with a fixed frequency slot interval, where the fixed frequency slot interval is set to the number of frequency slots required by the service. If the current available free spectrum block size is a multiple of the number of frequency slots required by the service, then traverse in ascending order starting from the starting frequency slot of the available free spectrum block with a fixed frequency slot interval. If the current available spectrum block is not a multiple of the number of frequency slots required by the service, then traverse in ascending order once starting from the starting frequency slot of the available spectrum block with a fixed frequency slot interval, and traverse in descending order once starting from the ending frequency slot of the available spectrum block. Count the spectrum blocks selected under each service allocation method and add them to set A. S502: After determining all allocation methods, the crosstalk level measurement value of each spectrum block in set A will be calculated according to the crosstalk level measurement formula. The formula for measuring crosstalk is as follows: In the crosstalk measurement formula, DCT o The value represents the crosstalk of fiber core o, which is the accumulated empty frequency slots on adjacent fiber cores of fiber core o in link l within the frequency slot index range; begin and end represent the start and end index values ​​of the frequency slot index range, respectively; l represents the link in the selected path; PL represents the set of links in the selected path; AO represents the set of adjacent fiber cores of fiber core o in link l. It is a binary variable; its value is 1 when slot f in fiber core ao is not occupied, and 0 otherwise; XT so SAO represents the cumulative crosstalk value of adjacent cores of core so; O represents the set of adjacent cores of core so; S503: Calculate the fragmentation degree measure value of each spectrum block in set A based on the fragmentation degree measure formula; The formula for measuring the degree of fragmentation is as follows: In the fragmentation degree measurement formula, MUG represents the cumulative value of the frequency slots occupied in all links within the index range; L represents the total set of links; This indicates the frequency slot occupancy status in link l. The value is 0 when slot f is not occupied, and 1 otherwise. S504: Calculate the crosstalk-fragmentation metric value for each spectral block in set A based on the crosstalk-fragmentation metric formula; The formula for measuring crosstalk-fragmentation is as follows: CFB=XT so +MUG In the crosstalk-fragmentation metric formula, CFB represents the sum of crosstalk and fragmentation within the index range, and the spectrum block with the smallest CFB value in set A will be selected for transmission.

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