Spectrum resource allocation method and system

Abstract

The invention relates to a spectrum resource allocation method and system, and the method comprises the steps: carrying out the initialization of an elastic optical network; obtaining a current service request and determining parameters of the current service request; placing the current service request in a service request queue, and calculating the priority of the service request in the service request queue according to the parameters; allocating a working path for the service request with the highest priority; judging whether spectrum resources of a working path corresponding to the service request are occupied or not, if not, allocating the spectrum resources to the working path, and executing the next step; if yes, whether a service request queue is returned or not is judged; judging whether the importance of the service request is greater than or equal to an importance threshold, if so, configuring a protection path for the working path, and allocating spectrum resources; if not, whether a service request queue is returned or not is judged; and calculating an optical signal-to-noise ratio value of the service request, and comparing the optical signal-to-noise ratio value with a preset threshold value to judge whether the connection is successful. According to the invention, effective resource allocation can be carried out on the service request.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum resource allocation, and in particular to a spectrum resource allocation method and system. Background Art

[0002] With the rapid development of modern communications technology, especially the rapid adoption and large-scale deployment of fiber-optic networks, spectrum resource allocation has become a crucial issue for improving network performance and reliability. Traditional spectrum resource allocation methods mostly focus on optimizing resource utilization. However, in real-world networks, efficient spectrum utilization is not the sole objective; network reliability and survivability are also crucial. In particular, when network failures occur, effectively managing and allocating resources to ensure stable network operation remains a pressing challenge in current spectrum resource allocation technologies.

[0003] While existing spectrum resource allocation methods have achieved some success in improving resource utilization, they often fail to fully consider the impact of shared risk link groups (SRLGs). SRLGs refer to situations in a communication network where multiple links may fail simultaneously due to common risk factors. Traditional resource allocation methods often fail to fully account for the characteristics of SRLGs. As a result, when a link fails, service requests may be blocked due to occupied or unavailable resources, thereby reducing network survivability and reliability.

[0004] Furthermore, traditional spectrum resource allocation methods often overlook the availability of links and nodes. Link and node availability directly impacts network service quality and stability. In particular, in the event of a link failure, failure to effectively assess link failure risk can lead to misallocation or waste of spectrum resources. While some current allocation methods can consider link availability to a certain extent, they still fall short in comprehensively assessing node availability and link risk.

[0005] Furthermore, existing spectrum resource allocation methods often ignore the importance of different service requests when considering resource occupancy status, resulting in the inability to achieve effective resource scheduling under high load or different service request priorities. It may even lead to excessive resource occupancy, causing resource bottlenecks or delays, and affecting the overall performance and service quality of the system.

[0006] In summary, existing spectrum resource allocation methods fail to comprehensively consider link availability, node availability, spectrum resource occupancy status, and the importance of different service requests in the network. Summary of the Invention

[0007] To this end, the technical problem to be solved by the present invention is to overcome the problem that the spectrum resource allocation method in the prior art fails to comprehensively consider the link availability, node availability, spectrum resource occupancy status, and importance of different service requests in the network.

[0008] To solve the above technical problems, the present invention provides a spectrum resource allocation method, comprising:

[0009] Step S1: Initializing the elastic optical network with C-band and L-band;

[0010] Step S2: Obtain the current service request and determine the parameters of the current service request;

[0011] Step S3: placing the current service request in a service request queue, and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a number of blocked service requests;

[0012] Step S4: Allocate a working path to the service request with the highest priority in the service request queue in order of priority;

[0013] Step S5: Determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, and if available spectrum resources exist in the L-band, prioritize allocating spectrum resources to the working path of the service request in the L-band, and proceed to step S6. If occupied, determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails.

[0014] Step S6: Determine whether the importance of the service request is greater than or equal to the importance threshold. If so, allocate a protection path to the working path, and if available spectrum resources are available in the C-band, prioritize allocating spectrum resources to the protection path of the service request in the C-band. If not, do not allocate a protection path to the working path, and determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails.

[0015] Step S7: Calculate the optical signal-to-noise ratio (OSNR) value of the service request with the protection path and compare it with a preset threshold. If the OSNR value is lower than the preset threshold, the service request connection fails; if the OSNR value is not lower than the preset threshold, the service request connection succeeds.

[0016] In one embodiment of the present invention, the method for initializing the elastic optical network having the C-band and the L-band in step S1 includes:

[0017] The elastic optical network with C-band and L-band is represented by G(V,E,T,F), where V represents the set of nodes in the network, E represents a set of optical fiber links in the network, and F = {f1,f2,...,f i ,....,f |F|} represents the number of spectrum slots available in each fiber link, f i represents the ith spectrum slot, |F| represents the total number of spectrum slots; T={t1,t2,…,t i ,…,t |T|} represents the set of foreseeable time slots in the network, t i represents the i-th time slot, and |T| represents the total number of time slots.

[0018] In one embodiment of the present invention, the link distance of the SRLG group in the elastic optical network is set to infinity to eliminate the link corresponding to the SRLG group, so as to reduce the link risk.

[0019] In one embodiment of the present invention, the method of obtaining the current service request and determining the parameters of the current service request in step S2 includes:

[0020] Generate a set of business requests, R represents the set of business requests, and the business request is represented by r(s,d,t a ,td max ,H t ,f,r)∈R(s,d,t a ,td max ,H t ,f,r) represents, where r is the importance of the business request, s represents the source node of the business request, d represents the destination node of the business request, t a is the arrival time of the service request, td max is the maximum tolerable delay time of the service request, H t is the duration of the service request, and f is the number of frequency slots required for the service request.

[0021] In one embodiment of the present invention, the method of calculating the priority of each service request in the service request queue according to the parameters of each service request in step S3 includes:

[0022] Construct the priority evaluation function SP(C r ,t a ,H t ,td max ), through the priority evaluation function SP(C r ,t a ,H t ,td max ) is used to express the priority of service requests for resource allocation. The formula is:

[0023]

[0024] Among them, C r represents the service request capacity, m represents the modulation format, Δ represents the basic bandwidth of each spectrum slot, and GB represents the protection bandwidth.

[0025] In one embodiment of the present invention, the method of allocating a working path to the service request with the highest priority in the service request queue in order of priority in step S4 includes:

[0026] The K shortest paths algorithm is used to calculate the working path of the service request with the highest priority. Specifically, the failure risk T of the service request based on the combination of link availability and node availability on the K candidate working paths is calculated, the link spectrum resource occupancy state continuity S is obtained, and the link weights W of the K candidate working paths are calculated based on the failure risk T of the service request and the link spectrum resource occupancy state continuity S. The paths are then arranged from small to large, and the optical fiber link with the smallest link weight W is selected as the preferred working path.

[0027] In one embodiment of the present invention, the method for calculating the failure risk T of a service request based on a combination of link availability and node availability on K candidate working paths includes:

[0028] Let the two endpoints of a fiber link of length D(x,y) be x and y, and the link availability A E (x,y) is defined as:

[0029] A E (x,y)=A D(x,y)

[0030] Availability A of node x in a fiber link of length D(x,y) N (x) is expressed as:

[0031] A N (x) = A

[0032] Where A is the availability of the optical fiber link per unit time length and satisfies:

[0033]

[0034] t MTBF =t MTTF -t MTTR

[0035] Among them, t MTTF It indicates the average time from when a system or equipment is operating normally without any fault until a fault occurs; t MTBFIndicates the time during which a system or device can continue to operate normally; t MTTR Indicates the recovery time of the system or equipment after a failure occurs;

[0036] Assume that the transmission path of a service request with importance r is P(s,d), where s is the source node and d is the destination node, then the link risk R E By link availability A E (x, y) and the importance r of the business request are calculated using the formula:

[0037] R E =r·(1-Π (x,y)∈(s,d) A E (x,y))

[0038] Node risk R of business request N By node availability A N (x) and the importance r of the business request are calculated using the formula:

[0039]

[0040] The failure risk T of a service request from source node s to sink node d is expressed as the link risk R E and node risk R N sum:

[0041] T=R E +R N .

[0042] In one embodiment of the present invention, the method of obtaining the link spectrum resource occupancy state continuity S and calculating the link weights W of K candidate working paths based on the failure risk T of the service request and the link spectrum resource occupancy state continuity S includes:

[0043] Combined with the initialized elastic optical network, the link spectrum resource occupancy state continuity S is calculated using the formula:

[0044]

[0045] in, represents the occupancy of the r-th service on the P-th link at the f-th spectrum slot in the t-th time slot, where occupied is 0 and idle is 1; OC represents the number of idle time-frequency spaces in the entire two-bit time-frequency domain, T represents the set of foreseeable time slots in the network, and F represents the set of available spectrum slots in each fiber link;

[0046] The link weight W is calculated based on the failure risk T of the service request and the continuity S of the link spectrum resource occupancy state. The formula is:

[0047]

[0048] Here, α represents the equalization factor.

[0049] In one embodiment of the present invention, configuring a protection path for the working path in step S6 further includes:

[0050] Configure links that do not intersect with the working path as protection paths.

[0051] To solve the above technical problems, the present invention provides a spectrum resource allocation system, comprising:

[0052] Initialization module: used to initialize the elastic optical network with C band and L band;

[0053] Acquisition module: used to obtain the current business request and determine the parameters of the current business request;

[0054] Calculation module: used for placing the current service request in the service request queue and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a plurality of blocked service requests;

[0055] Allocation module: used to allocate a work path to the highest priority service request in the service request queue according to the priority order;

[0056] The first judgment module is used to determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, if available spectrum resources are available in the L-band, spectrum resources are preferentially allocated to the working path of the service request in the L-band, and step S6 is executed. If occupied, it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails.

[0057] The first judgment module is used to determine whether the importance of the service request is greater than or equal to the importance threshold. If so, a protection path is allocated to the working path, and when available spectrum resources are available in the C-band, spectrum resources are preferentially allocated to the protection path of the service request in the C-band. If not, the protection path is not allocated to the working path, and it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails.

[0058] The first judgment module is used to calculate the optical signal-to-noise ratio value of the service request with the protection path and compare it with the preset threshold. If the optical signal-to-noise ratio value is lower than the preset threshold, the service request connection fails; if the optical signal-to-noise ratio value is not lower than the preset threshold, the service request connection succeeds.

[0059] The above technical solution of the present invention has the following advantages over the prior art:

[0060] The present invention can simultaneously consider the link failure risk T and the spectrum resource occupancy state continuity S, providing a more comprehensive and accurate basis for link selection. This can avoid selecting links with frequent failures or unstable resource occupancy, ensuring efficient network operation and stable and balanced resource allocation.

[0061] When allocating resources to service requests, the present invention determines whether to configure dedicated protection paths based on the importance of different service requests. Specifically, service requests with lower importance may not be allocated dedicated protection paths, while service requests with higher importance must be allocated dedicated protection paths. This allocation method ensures the rational use of network resources, avoids resource waste caused by over-protection, and improves the reliability of important service requests.

[0062] The spectrum resource allocation method of the present invention strives to improve resource utilization while enhancing network reliability, stability and survivability by comprehensively considering the availability of links and nodes, sharing risks and service request priorities. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0064] Figure 1 is a flow chart of the method of the present invention;

[0065] Figure 2 is a network topology diagram including a shared risk link group in an embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of possible operational problems and time analysis that may occur during the operation of a device or system according to an embodiment of the present invention;

[0067] Figure 4 Schematic diagram of optical fiber link weight calculation according to an embodiment of the present invention;

[0068] Figure 5 This is an example diagram of a path with and without protection in an embodiment of the present invention. DETAILED DESCRIPTION

[0069] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0070] Example 1

[0071] Reference Figure 1 As shown, the present invention relates to a spectrum resource allocation method, comprising:

[0072] Step S1: Initializing the elastic optical network with C-band and L-band;

[0073] Step S2: Obtain the current service request and determine the parameters of the current service request;

[0074] Step S3: placing the current service request in a service request queue, and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a number of service requests blocked within the maximum tolerable delay time;

[0075] It should be noted that this embodiment assumes that the service request queue includes several blocked service requests. In actual use, the speed of generating service requests may be faster than the speed of processing service requests. The service request queue includes not only several blocked service requests, but also several newly generated service requests to be processed. These newly generated service requests will be prioritized together with the blocked service requests.

[0076] Step S4: Allocate a working path to the service request with the highest priority in the service request queue in order of priority;

[0077] Step S5: Determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, and if available spectrum resources exist in the L-band, prioritize allocating spectrum resources to the working path of the service request in the L-band, and proceed to step S6. If occupied, determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails.

[0078] Step S6: Determine whether the importance of the service request is greater than or equal to the importance threshold. If so, allocate a protection path to the working path, and if available spectrum resources are available in the C-band, prioritize allocating spectrum resources to the protection path of the service request in the C-band. If not, do not allocate a protection path to the working path, and determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails.

[0079] Step S7: Calculate the optical signal-to-noise ratio (OSNR) value of the service request with the protection path and compare it with a preset threshold. If the OSNR value is lower than the preset threshold, the service request connection fails; if the OSNR value is not lower than the preset threshold, the service request connection succeeds.

[0080] The following is a detailed introduction to this embodiment:

[0081] The spectrum resource allocation method of this embodiment is essentially a dedicated path protection resource optimization method based on a shared risk link group (SRLG), and mainly includes the following steps:

[0082] Step 1: Initialize the elastic optical network with C-band and L-band. The elastic optical network is represented by G(V,E,T,F), where V represents the set of nodes in the network, E represents the set of fiber links in the network, and F = {f1,f2,...,f i ,....,f |F|} represents the number of spectrum slots available in each fiber link, f i represents the ith spectrum slot, |F| represents the total number of spectrum slots; T={t1,t2,…,t i ,…,t |T|} represents the set of foreseeable time slots in the network, t i represents the i-th time slot, and |T| represents the total number of time slots.

[0083] It is worth mentioning that this embodiment sets the link distance of the SRLG group in the elastic optical network to infinity to eliminate the links corresponding to the SRLG group, which is equivalent to the fact that there is no link corresponding to the SRLG group in actual use, so as to reduce the link risk. The SRLG group can be defined in advance, for example Figure 2 Taking node 5 as an example, node 5 to node 4 and node 5 to node 10 are both pre-defined SRLG groups. If node 5 needs to connect to node 6, then nodes 5, 4, and 6 are not accessible, and nodes 5, 2, 0, 3, 4, and 6 need to be connected.

[0084] Step 2: Generate a set of service requests (service connection requests), R represents the set of service requests, and the service request is represented by r(s, d, t a ,td max ,H t ,f,r)∈R(s,d,t a ,td max ,H t ,f,r) represents, where r is the importance of the business request, s represents the source node of the business request, d represents the destination node of the business request, t a is the arrival time of the service request, td max is the maximum tolerable delay time of the service request, H t is the duration of the service request, and f is the number of frequency slots required for the service request.

[0085] Step 3: Set the priority of the service request, determine the urgency of the service request, and prioritize resource allocation for the service request with high urgency. In order to more accurately reflect the priority of service requests for resource allocation in the C-band and L-band elastic optical networks and optimize resource allocation, this embodiment constructs a priority evaluation function SP(C r ,t a ,H t ,td max ), through the priority evaluation function SP(C r ,t a ,H t ,td max ) is used to express the priority of service requests for resource allocation. The formula is:

[0086]

[0087] Among them, C r represents the service request capacity size, m represents the modulation format (BPSK: m=1; QPSK: m=2; 4-QAM: m=3; 8-QAM: m=4); Δ represents the basic bandwidth of each spectrum slot (fixed at 12.5 GHz), and GB represents the guard bandwidth.

[0088] Step 4: Use the K shortest paths algorithm (KSP algorithm) to calculate K candidate working paths for the service request with the highest priority, including: calculating the failure risk T of the service request based on the combination of link availability and node availability on the K candidate working paths, obtaining the link spectrum resource occupancy state continuity S, calculating the link weights W of the K candidate working paths based on the failure risk T of the service request and the link spectrum resource occupancy state continuity S, arranging the link weights W from small to large, and preferentially selecting the optical fiber link with the smallest link weight W as the preferred working path.

[0089] Link availability refers to the probability that a fiber link in an elastic optical network can maintain normal operation within a given time. When a link fails, it may directly affect the performance of the entire network.

[0090] The availability A of the optical fiber link per unit time length is defined as:

[0091]

[0092] t MTBF =t MTTF -t MTTR

[0093] Among them, t MTTFMean Time to Failure (MTTF) refers to the average time it takes for a system or device to operate normally without any faults until a fault occurs. MTTF The larger the value, the stronger the system's ability to continue operating under normal working conditions and the lower the probability of failure. MTBF Mean Time Between Failures (MTBF) refers to the time during which a system or device can operate normally continuously. MTBF The larger the value, the higher the reliability of the system and the lower the frequency of failure. MTTR Mean Time to Repair (MTTR) refers to the time it takes for a system or device to recover after a failure occurs. MTTR A smaller value means that the system recovers faster. Figure 3 shown.

[0094] Therefore, on the one hand, by a larger t MTTF Value and t MTBF The value can ensure that the equipment or system has the least possible failures during operation and improve the overall reliability and availability of the system; on the other hand, by reducing the t MTTR value, which can improve availability and recovery capabilities.

[0095] Let the two endpoints of a fiber link of length D(x,y) be x and y, and the link availability A E (x,y) can be defined as:

[0096] A E (x,y)=A D(x,y)

[0097] Availability A of node x in a fiber link of length D(x,y) N (x) represents the following:

[0098] A N (x) = A

[0099] Assume that the transmission path of a service request with importance r is P(s,d), where s is the source node and d is the destination node, then the link risk R E By link availability A E (x, y) and the importance r of the business request are calculated using the formula:

[0100] R E =r·(1-∏ (x,y)∈(s,d) A E (x,y))

[0101] Node risk R of business request N By node availability A N (x) and the importance r of the business request are calculated using the formula:

[0102]

[0103] The failure risk T of a service request from source node s to sink node d is expressed as the link risk R E and node risk R N sum:

[0104] T=R E +R N

[0105] Combined with the initialized elastic optical network, the link spectrum resource occupancy state continuity S is calculated using the following formula:

[0106]

[0107] in, represents the occupancy of the r-th service on the P-th link at the f-th spectrum slot in the t-th time slot, where occupied is 0 and idle is 1; OC represents the number of idle time-frequency spaces in the entire two-bit time-frequency domain, T represents the set of foreseeable time slots in the network, and F represents the set of available spectrum slots in each fiber link;

[0108] The link weight W is calculated by combining the service request failure risk T and the link spectrum resource occupancy state continuity S. When the service request failure risk T is small and the link spectrum resource occupancy state continuity S is continuous, the link state selects a better link resource regularity and path state. The formula is as follows:

[0109]

[0110] Here, α represents the equalization factor.

[0111] Step 5: Determine whether the spectrum resources of the working path corresponding to the service request with the highest priority are occupied. If not, when there are available spectrum resources in the L-band, the spectrum resources for the service request are first selected in the L-band (if there are no spectrum resources in the L-band, the C-band can be considered). The spectrum resources are traversed from the front of the L-band. For example, in the following case, the spectrum resources are selected from f 71 to f 100 Forward traversal of spectrum resources) allocates spectrum resources with maximum optical signal-to-noise ratio and executes step 6; if occupied, determine whether the service request is within the maximum tolerable delay time. If so, return the service request (at this time, the service request becomes a blocked service request) to the service request queue; if not, the service request connection fails.

[0112] Preferably, since this embodiment uses the KSP algorithm to select K paths, when it is determined in step 5 that the spectrum resources of the working path corresponding to the service request with the highest priority are occupied, the path with the smallest link weight W can be found again from the remaining K-1 paths as the working path, and then it is determined whether the spectrum resources are occupied. If the spectrum resources are always occupied, this step can be looped until all K paths are traversed. After the traversal, it is determined whether the service request is within the maximum tolerable delay time to decide whether the service request should be returned to the service request queue.

[0113] Step 6: Determine whether the importance r of the service request is greater than or equal to the importance threshold r0. If so (r is greater than r0), configure a protection path for the working path, and if there is available spectrum resource in the C band, prioritize the C band (if there is no spectrum resource in the C band, consider the L band) as the protection path for the service request through the last hit method (traverse the spectrum resource from the end of the C band, for example, in the following case, from f 70 to f1 to traverse the spectrum resources in reverse) allocate the maximum optical signal-to-noise ratio spectrum resources (if there are no available spectrum resources in both the C-band and the L-band, determine whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue; if not, the service request connection fails); if not (r is less than r0), do not configure a protection path for the working path to reduce network operation time and simplify operation complexity, and determine whether the service request is within the maximum tolerable delay time. If so, return the service request (the service request becomes a blocked service request at this time) to the service request queue; if not, the service request connection fails.

[0114] Step 7: If there are sufficient available spectrum resource segments, calculate the optical signal-to-noise ratio (OSNR) value of the service request with the protection path and compare it with the preset threshold. If the OSNR value is lower than the preset threshold, the service request connection fails; if the OSNR value is not lower than the preset threshold, the service request connection succeeds.

[0115] The present invention is described in detail below through a specific case:

[0116] Figure 2 The network topology shown, including SRLGs, has 14 nodes and 21 bidirectional links. This embodiment pre-sets links (5,4), (5,10) and (8,3), (8,11) as two SRLG groups in the network. The initial balancing factor α of the link weight W is set to 0.5. In this case, the failure risk T of the service request and the continuity of the link spectrum resource occupancy state S have the same weight influence. The value on the fiber link represents the physical distance of the link in kilometers. The basic bandwidth of each spectrum slot is set to 12.5 GHz, and the capacity of the fiber link is 100 spectrum slots (i.e., f1 to f2).100 ), where the C band occupies 30 spectrum slots (i.e. f1 to f 70 ), L band occupies 70 spectrum slots (i.e. f 71 to f 100 The maximum foreseeable number of time slots in the elastic optical network is 20. The capacity of generated requests is uniformly distributed in the range of [50,100] Gbps, and the duration of service requests is uniformly distributed in the range of [1,3] time units, using different modulation format levels.

[0117] t of the optical fiber link MTBF and t MTTR are 7600h / km and 12h / km respectively, and the node t MTBF and t MTTR They are 4950h / km and 2h / km respectively, and the fiber availability per unit length is 0.9984 and the node availability is 0.9996.

[0118] The specific embodiment can be divided into two parts:

[0119] on the one hand, Figure 4 This example shows the link weight calculation for selecting a working path for a service request with an importance r of 0.6. According to the link weight W formula, the link weight value W of path 1 can be obtained. p1 =1.1431; link weight value W of path 2 p2 =0.4722; link weight value W of path 3 p3 =0.7153. The smaller the W value, the better the regularity of the selected link resources and the better the path status.

[0120] The present invention can simultaneously comprehensively consider the link failure risk T and the spectrum resource occupancy state continuity S, providing a more comprehensive and accurate basis for link selection. This can avoid selecting links with frequent failures or unstable resource occupancy, ensure the efficient operation of the network, and ensure the stability and balance of resource allocation.

[0121] On the other hand, when allocating resources for service requests, the system will decide whether to configure a dedicated protection path for each service request based on its importance. Specifically, service requests with lower importance may not be configured with a dedicated protection path, while service requests with higher importance must be configured with a dedicated protection path. This allocation method ensures the rational use of network resources, avoids resource waste due to over-protection, and improves the reliability of important service requests. Figure 5 shown.

[0122] For low-importance service requests: Since no backup path is configured for these service requests, if the working path fails, the service requests will be immediately interrupted. The recovery process may require policies such as fast reroute, but there are no safeguards.

[0123] For high-priority service requests, dedicated protection paths must be allocated. The signal for the service request is lost only if both the working and protection paths fail. This safeguard effectively prevents service interruptions for high-priority services caused by single points of failure.

[0124] To optimize spectrum resource allocation, this invention proposes a path-independent strategy, which means that resource allocation for the working and protection paths within the network is relatively independent. Specifically, the working path prioritizes the L-band to ensure efficient spectrum utilization and signal quality; the protection path prioritizes the C-band, using a last-hit method for resource allocation. This allocation strategy helps improve overall network survivability and transmission quality, and effectively avoids resource conflicts between different service requests.

[0125] Example 2

[0126] This embodiment provides a spectrum resource allocation system, including:

[0127] Initialization module: used to initialize the elastic optical network with C band and L band;

[0128] Acquisition module: used to obtain the current business request and determine the parameters of the current business request;

[0129] Calculation module: used for placing the current service request in the service request queue and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a plurality of blocked service requests;

[0130] Allocation module: used to allocate a work path to the highest priority service request in the service request queue according to the priority order;

[0131] The first judgment module is used to determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, if available spectrum resources are available in the L-band, spectrum resources are preferentially allocated to the working path of the service request in the L-band, and step S6 is executed. If occupied, it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails.

[0132] The first judgment module is used to determine whether the importance of the service request is greater than or equal to the importance threshold. If so, a protection path is allocated to the working path, and when available spectrum resources are available in the C-band, spectrum resources are preferentially allocated to the protection path of the service request in the C-band. If not, the protection path is not allocated to the working path, and it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails.

[0133] The first judgment module is used to calculate the optical signal-to-noise ratio value of the service request with the protection path and compare it with the preset threshold. If the optical signal-to-noise ratio value is lower than the preset threshold, the service request connection fails; if the optical signal-to-noise ratio value is not lower than the preset threshold, the service request connection succeeds.

[0134] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0135] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A spectrum resource allocation method, characterized by: include: Step S1: Initializing the elastic optical network with C-band and L-band; Step S2: Obtain the current service request and determine the parameters of the current service request; Step S3: placing the current service request in a service request queue, and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a number of blocked service requests; Step S4: Allocate a working path to the service request with the highest priority in the service request queue in order of priority; Step S5: Determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, and if available spectrum resources exist in the L-band, prioritize allocating spectrum resources to the working path of the service request in the L-band, and proceed to step S6. If occupied, determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails. Step S6: Determine whether the importance of the service request is greater than or equal to the importance threshold. If so, allocate a protection path to the working path, and if available spectrum resources are available in the C-band, prioritize allocating spectrum resources to the protection path of the service request in the C-band. If not, do not allocate a protection path to the working path, and determine whether the service request is within the maximum tolerable delay time. If so, return the service request to the service request queue. If not, the service request connection fails. Step S7: Calculate the optical signal-to-noise ratio (OSNR) value of the service request with the protection path and compare it with a preset threshold. If the OSNR value is lower than the preset threshold, the service request connection fails; if the OSNR value is not lower than the preset threshold, the service request connection succeeds.

2. The spectrum resource allocation method according to claim 1, wherein: The method for initializing the elastic optical network having the C-band and the L-band in step S1 includes: The elastic optical network with C-band and L-band is represented by G(V,E,T,F), where V represents the set of nodes in the network, E represents a set of optical fiber links in the network, and F = {f1,f2,...,f i ,....,f |F| } represents the number of spectrum slots available in each fiber link, f i represents the ith spectrum slot, |F| represents the total number of spectrum slots; T={t1,t2,…,t i ,…,t |T| } represents the set of foreseeable time slots in the network, t i represents the i-th time slot, and |T| represents the total number of time slots.

3. The spectrum resource allocation method according to claim 1, wherein: The link distance of the SRLG group in the elastic optical network is set to infinity to eliminate the links corresponding to the SRLG group to reduce link risks.

4. The spectrum resource allocation method according to claim 1, wherein: The method of obtaining the current service request and determining the parameters of the current service request in step S2 includes: Generate a set of business requests, R represents the set of business requests, and the business request is represented by r(s,d,t a ,td max ,H t ,f,r)∈R(s,d,t a ,td max ,H t ,f,r) represents, where r is the importance of the business request, s represents the source node of the business request, d represents the destination node of the business request, t a is the arrival time of the service request, td max is the maximum tolerable delay time of the service request, H t is the duration of the service request, and f is the number of frequency slots required for the service request.

5. The spectrum resource allocation method according to claim 3, wherein: The method of calculating the priority of each service request in the service request queue according to the parameters of each service request in step S3 includes: Construct the priority evaluation function SP(C r ,t a ,H t ,td max ), through the priority evaluation function SP(C r ,t a ,H t ,td max ) is used to express the priority of service requests for resource allocation. The formula is: Among them, C r represents the service request capacity, m represents the modulation format, Δ represents the basic bandwidth of each spectrum slot, and GB represents the protection bandwidth.

6. The spectrum resource allocation method according to claim 1, wherein: The method of allocating a working path to the service request with the highest priority in the service request queue in the order of priority in step S4 includes: The K shortest paths algorithm is used to calculate the working path of the service request with the highest priority. Specifically, the failure risk T of the service request based on the combination of link availability and node availability on the K candidate working paths is calculated, the link spectrum resource occupancy state continuity S is obtained, and the link weights W of the K candidate working paths are calculated based on the failure risk T of the service request and the link spectrum resource occupancy state continuity S. The paths are then arranged from small to large, and the optical fiber link with the smallest link weight W is selected as the preferred working path.

7. The spectrum resource allocation method according to claim 5, wherein: The method for calculating the failure risk T of a service request based on a combination of link availability and node availability on K candidate working paths includes: Let the two endpoints of a fiber link of length D(x,y) be x and y, and the link availability A E (x,y) is defined as: TO E (x,y)=A D(x,y) Availability A of node x in a fiber link of length D(x,y) N (x) is expressed as: A N (x)=A Where A is the availability of the optical fiber link per unit time length and satisfies: t MTBF =t MTTF -t MTTR Among them, t MTTF It indicates the average time from when a system or equipment is operating normally without any fault until a fault occurs; t MTBF Indicates the time during which a system or device can continue to operate normally; t MTTR Indicates the recovery time of the system or equipment after a failure occurs; Assume that the transmission path of a service request with importance r is P(s,d), where s is the source node and d is the destination node, then the link risk R E By link availability A E (x, y) and the importance r of the business request are calculated using the formula: R E =r·(1-Π (x,y)∈(s,d) A E (x,y)) Node risk R of business request N By node availability A N (x) and the importance r of the business request are calculated using the formula: The failure risk T of a service request from source node s to sink node d is expressed as the link risk R E and node risk R N sum: T=R E +R N 。 8. The spectrum resource allocation method according to claim 6, wherein: The method of obtaining the link spectrum resource occupancy state continuity S and calculating the link weights W of K candidate working paths according to the failure risk T of the service request and the link spectrum resource occupancy state continuity S includes: Combined with the initialized elastic optical network, the link spectrum resource occupancy state continuity S is calculated using the formula: in, represents the occupancy of the r-th service on the P-th link at the f-th spectrum slot in the t-th time slot, where occupied is 0 and idle is 1; OC represents the number of idle time-frequency spaces in the entire two-bit time-frequency domain, T represents the set of foreseeable time slots in the network, and F represents the set of available spectrum slots in each fiber link; The link weight W is calculated based on the failure risk T of the service request and the continuity S of the link spectrum resource occupancy state. The formula is: Here, α represents the equalization factor.

9. The spectrum resource allocation method according to claim 1, wherein: The step S6 of configuring a protection path for the working path further includes: Configure links that do not intersect with the working path as protection paths.

10. A spectrum resource allocation system, characterized by: include: Initialization module: used to initialize the elastic optical network with C band and L band; Acquisition module: used to obtain the current business request and determine the parameters of the current business request; Calculation module: used for placing the current service request in the service request queue and calculating the priority of each service request in the service request queue according to the parameters of each service request, wherein the service request queue includes a plurality of blocked service requests; Allocation module: used to allocate a work path to the highest priority service request in the service request queue according to the priority order; The first judgment module is used to determine whether the spectrum resources of the working path corresponding to the highest-priority service request are occupied. If not, if available spectrum resources are available in the L-band, spectrum resources are preferentially allocated to the working path of the service request in the L-band, and step S6 is executed. If occupied, it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails. The first judgment module is used to determine whether the importance of the service request is greater than or equal to the importance threshold. If so, a protection path is allocated to the working path, and when available spectrum resources are available in the C-band, spectrum resources are preferentially allocated to the protection path of the service request in the C-band. If not, the protection path is not allocated to the working path, and it is determined whether the service request is within the maximum tolerable delay time. If so, the service request is returned to the service request queue. If not, the service request connection fails. The first judgment module is used to calculate the optical signal-to-noise ratio value of the service request with the protection path and compare it with the preset threshold. If the optical signal-to-noise ratio value is lower than the preset threshold, the service request connection fails; if the optical signal-to-noise ratio value is not lower than the preset threshold, the service request connection succeeds.

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