A method and apparatus for minimizing network spectrum fragmentation for routing resource allocation

Abstract

The application discloses a network spectrum fragmentation minimization routing resource allocation method and device, the method comprises two stages of path selection and spectrum allocation, the path selection stage takes maximizing path resource utilization as the target, obtains optical network topology information, filters the optimal path through quantifying spectrum resource availability and concentration degree of the link and the path, and forms a candidate path set; the spectrum allocation stage takes minimizing spectrum fragmentation generation and reducing service blocking rate as the target, converts the IP service into optical layer frequency gap demand, filters the continuous idle spectrum block meeting the spectrum constraint condition in the candidate path set to form a frequency block candidate set, determines the optimal frequency block through quantifying the close degree of the frequency block and the occupied resource and the influence degree of the frequency block deployment on the link resource, completes service allocation, and updates the link frequency gap use state in real time after the allocation. The application effectively reduces spectrum fragmentation, improves spectrum resource utilization and network transmission reliability, and adapts to high dynamic and high burst service demand.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, specifically relating to a method and apparatus for minimizing network spectrum fragmentation in routing resource allocation. Background Technology

[0002] With the rapid development of technologies such as 5G, IoT, and virtual reality, network services are becoming increasingly diversified and dynamic, and IP data traffic is surging continuously. The rigidity of traditional network architectures is becoming more and more prominent, making it difficult to meet the network requirements of high reliability, high efficiency, and high flexibility. Against this backdrop, the "IP+optical" network architecture, with its collaborative control capabilities at the IP and optical layers, has become the core choice for backbone network upgrades, effectively alleviating the problems of resource waste and complex operation and maintenance in traditional networks.

[0003] To further improve spectrum resource utilization, Elastic Optical Networks (EON) are gradually replacing traditional Wavelength Division Multiplexing (WDM) optical networks. Based on Orthogonal Frequency Division Multiplexing (OFDM) technology, EON subdivides spectrum resources into flexibly combinable slot units, dynamically adapting to the bandwidth requirements of different services and significantly improving resource adaptability. However, in practical applications, EON spectrum allocation must adhere to constraints of spectrum continuity, consistency, and non-overlap. In dynamic scenarios with frequent service establishment and disconnection, spectrum fragmentation is easily generated. These fragments are scattered and difficult to align, resulting in a large number of idle slots being unused, leading to network congestion and severely impacting network performance.

[0004] Existing routing and spectrum allocation (RSA) technologies have significant limitations. Some solutions focus solely on path selection optimization, neglecting the impact of spectrum allocation on fragmentation. Traditional first-match (FF) and random-match (RF) spectrum allocation strategies lack a comprehensive consideration of frequency block distribution characteristics and network resource status, making it difficult to suppress spectrum fragmentation at its source. Therefore, how to reduce spectrum fragmentation and lower network congestion rates through coordinated optimization of routing and spectrum allocation has become a key technical challenge in the field of IP+optical network resource management. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a routing resource allocation method and apparatus for minimizing network spectrum fragmentation, so as to solve or partially solve the problems mentioned in the background art.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a routing resource allocation method for minimizing network spectrum fragmentation, comprising a path selection phase and a spectrum allocation phase: The path selection phase aims to maximize path resource utilization by acquiring optical network topology information and screening the optimal path by quantifying the spectral resource availability and concentration of links and paths, thus forming a candidate path set. The spectrum allocation phase aims to minimize spectrum fragmentation and reduce service congestion. It converts IP services into optical layer slot requirements, selects consecutive idle spectrum blocks that meet the spectrum constraints from the candidate path set to form a frequency block candidate set, and determines the optimal frequency block and completes service allocation by quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources. After allocation, the link slot usage status is updated in real time.

[0007] As a preferred method for routing resource allocation that minimizes network spectrum fragmentation, the path selection phase involves filtering for optimal paths by quantifying the availability and concentration of spectrum resources across links and paths, forming a candidate path set. Specifically, this includes: S11: Calculate the weighted spectrum resource reachability (SRA) of each link in all candidate paths. The weighted spectrum resource reachability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows:

[0008] In the formula, For link Spectrum resource availability FS For link The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive free spectrum blocks; S12: Calculate the path SRA of the candidate path based on the weighted spectrum resource reachability (SRA) of each link. The calculation method is as follows:

[0009] In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on; S13: According to the K-MSRA algorithm, sort the candidate paths in descending order of their SRA values, and select the first K non-intersecting paths to form a candidate path set. .

[0010] As a preferred method for routing resource allocation that minimizes network spectrum fragmentation, during the spectrum allocation phase, when converting IP services into optical layer bandwidth requirements, the number of bandwidths required for the service is calculated. The calculation method is as follows:

[0011] In the formula, For business Data transmission rate, For the first n The unit capacity of the frequency slot under each modulation type For the protection interval of service transmission, Indicates to Round down.

[0012] As a preferred method for routing resource allocation to minimize network spectrum fragmentation, the spectrum constraints include constraints on spectrum continuity, spectrum consistency, and spectrum non-overlapping. The spectrum continuity constraint requires that the spectrum blocks allocated to services consist of continuous frequency slots; The spectrum consistency constraint requires that the spectrum resources allocated on all optical fiber links through which the service passes be the same. The spectrum non-overlap constraint stipulates that a frequency slot on the same link cannot be occupied by multiple services simultaneously.

[0013] As a preferred method for routing resource allocation that minimizes network spectrum fragmentation, the spectrum allocation phase quantifies the closeness between frequency blocks and already occupied resources through frequency block aggregation. The calculation method is as follows:

[0014]

[0015] In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration.

[0016] As a preferred method for routing resource allocation that minimizes network spectrum fragmentation, the spectrum allocation phase quantifies the impact of frequency block deployment on link resources through frequency block weight values. The calculation process includes: S211: Calculate the initial weight of the link, using the following formula:

[0017] In the formula, For link Upper m A free spectrum block For link Upper m The number of frequency slots contained in a spectrum block For link The number of free spectrum blocks. For link The weight value; S212: Perform difference normalization on the initial link weights to obtain the frequency block weight values, using the following formula:

[0018]

[0019] In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle j After one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block.

[0020] As a preferred method for routing resource allocation that minimizes network spectrum fragmentation, the spectrum allocation phase, specifically the process of determining the optimal frequency block and completing service allocation, includes: S221: Calculate the link spectrum configuration deviation SAD for each frequency block, wherein the spectrum configuration deviation SAD is the product of the frequency block concentration CD and the frequency block weight value W of the corresponding frequency block; S222: Calculate the path SAD for each frequency block using the following method:

[0021] In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middle j Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on; S223: Select the frequency block with the smallest path SAD value for service allocation; if there are multiple frequency blocks with the same path SAD value, use the first matching FF algorithm to select the frequency block according to the frequency slot index value from smallest to largest.

[0022] In a second aspect, the present invention provides a routing resource allocation apparatus for minimizing network spectrum fragmentation, comprising: The path selection module is used to obtain optical network topology information with the goal of maximizing path resource utilization, and to filter the optimal path by quantifying the spectral resource availability and concentration of links and paths to form a candidate path set; The spectrum allocation module is used to convert IP services into optical layer frequency slot requirements with the goal of minimizing spectrum fragmentation and reducing service congestion rate. It selects continuous idle spectrum blocks that meet the spectrum constraints in the candidate path set to form a frequency block candidate set. By quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources, it determines the optimal frequency block and completes the service allocation. After allocation, it updates the link frequency slot usage status in real time.

[0023] As a preferred solution for a routing resource allocation device that minimizes network spectrum fragmentation, the path selection module includes: The Link SRA Calculation Submodule is used to calculate the Weighted Spectrum Resource Availability (SRA) of each link in all candidate paths. The Weighted Spectrum Resource Availability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows:

[0024] In the formula, For link Spectrum resource availability FS For link The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive free spectrum blocks; The path SRA calculation submodule calculates the path SRA of candidate paths based on the weighted spectrum resource reachability SRA of each link. The calculation method is as follows:

[0025] In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on; The K-MSRA path selection submodule is used to sort the candidate paths in descending order of their SRA values ​​according to the K-MSRA algorithm, and select the first K non-intersecting paths to form a candidate path set. .

[0026] As a preferred solution for a routing resource allocation device that minimizes network spectrum fragmentation, the spectrum allocation module calculates the number of frequency slots required for the service when converting IP services into optical layer frequency slot requirements. The calculation method is as follows:

[0027] In the formula, For business Data transmission rate, For the first n The unit capacity of the frequency slot under each modulation type For the protection interval of service transmission, Indicates to Round down.

[0028] As a preferred solution for a routing resource allocation device that minimizes network spectrum fragmentation, the spectrum allocation module includes spectrum constraints such as spectrum continuity, spectrum consistency, and spectrum non-overlapping constraints. The spectrum continuity constraint requires that the spectrum blocks allocated to services consist of continuous frequency slots; The spectrum consistency constraint requires that the spectrum resources allocated on all optical fiber links through which the service passes be the same. The spectrum non-overlap constraint stipulates that a frequency slot on the same link cannot be occupied by multiple services simultaneously.

[0029] As a preferred solution for a routing resource allocation device that minimizes network spectrum fragmentation, the spectrum allocation module quantifies the closeness between frequency blocks and already occupied resources through frequency block centralization. The calculation method is as follows:

[0030]

[0031] In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration.

[0032] As a preferred embodiment of a routing resource allocation device for minimizing network spectrum fragmentation, the spectrum allocation module further includes: The initial link weight calculation submodule is used to calculate the initial link weight, using the following formula:

[0033] In the formula, For link Upper m A free spectrum block For link Upper m The number of frequency slots contained in a spectrum block For link The number of free spectrum blocks. For link The weight value; The normalization processing submodule is used to perform difference normalization on the initial link weights to obtain the frequency block weight values, using the following formula:

[0034]

[0035] In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle j After one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block; The link SAD calculation submodule is used to calculate the link spectrum configuration deviation SAD of each frequency block. The spectrum configuration deviation SAD is the product of the frequency block concentration CD and the frequency block weight value W of the corresponding frequency block. The path SAD calculation submodule is used to calculate the path SAD of each frequency block in the following way:

[0036] In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middlej Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on; The service allocation submodule is used to select the frequency block with the smallest path SAD value for service allocation; if there are multiple frequency blocks with the same path SAD value, the first matching FF algorithm is used to select the frequency block according to the frequency slot index value from smallest to largest.

[0037] Thirdly, the present invention provides an electronic device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the processor, when executing the program or instructions, implements a routing resource allocation method for minimizing network spectrum fragmentation as described in the first aspect or any possible implementation thereof.

[0038] Fourthly, the present invention provides a computer-readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the routing resource allocation method for minimizing network spectrum fragmentation in the first aspect or any possible implementation thereof.

[0039] From the above description, the beneficial effects of the present invention can be summarized as follows: First, in the path selection stage, this invention uses Spectrum Resource Availability (SRA) to screen paths with abundant and concentrated idle resources, thus avoiding the fragmentation risks caused by resource dispersion from the source. In the spectrum allocation stage, it uses Spectrum Configuration Deviation (SAD) to comprehensively consider the closeness between frequency blocks and occupied resources and the impact of frequency block deployment on links, prioritizing frequency blocks with strong resource integration capabilities, minimizing spectrum fragmentation after service allocation, and solving the core problems of fragmentation difficulty in alignment and ineffective utilization of idle resources in elastic optical networks.

[0040] Second, this invention uses the K-MSRA algorithm to filter the optimal candidate path set of K non-intersecting links, improving the success rate of establishing working paths and providing sufficient selection space for subsequent spectrum allocation. At the same time, in spectrum allocation, the frequency block with the smallest SAD value is selected first. Especially when the frequency block weight value is negative, perfect service adaptation can be achieved, avoiding resource waste caused by spectrum fragmentation, significantly reducing the probability of service being blocked due to unmet bandwidth requirements, and ensuring smooth network service carrying.

[0041] Third, in the path selection stage, this invention focuses on maximizing resource utilization. It uses the SRA index to accurately quantify the availability and concentration of path resources, ensuring that the selected path can efficiently adapt to business needs. In the spectrum allocation stage, the frequency block concentration (CD) guides frequency blocks to move closer to occupied resources, reducing resource gap waste. At the same time, the frequency block weight value (W) quantifies the carrying capacity of frequency blocks, achieving optimal resource matching, significantly improving the overall spectrum resource utilization, and alleviating the resource pressure caused by the surge in IP traffic.

[0042] Fourth, this invention addresses the high burstiness and high dynamism of services in "IP+optical" networks by dynamically calculating the number of frequency slots required for services and flexibly adjusting modulation formats and frequency slot allocation schemes to achieve precise adaptation between IP services and optical layer frequency slots. The dual screening mechanism of candidate path sets and frequency block candidate sets gives the network stronger flexible adjustment capabilities, enabling it to quickly respond to service establishment and disconnection requests, and perfectly adapt to the diverse service needs brought about by emerging technologies such as virtual reality and the Internet of Things.

[0043] Fifth, the present invention strictly adheres to the constraints of spectrum continuity, spectrum consistency, and spectrum non-overlap during spectrum allocation, effectively avoiding mutual interference between signals and ensuring service transmission quality. At the same time, the design of K non-intersecting candidate paths not only improves the fault tolerance rate of path selection but also enhances the network's fault resistance capability, providing a stable and reliable network environment for service transmission. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A flowchart illustrating the overall process of a routing resource allocation method for minimizing network spectrum fragmentation provided in this embodiment of the invention. Figure 2 A network topology diagram provided for embodiments of the present invention; Figure 3 This is a schematic diagram of the spectrum state provided in an embodiment of the present invention; Figure 4 This is an architecture diagram of a routing resource allocation device for minimizing network spectrum fragmentation provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0047] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this invention should have the ordinary meaning understood by those skilled in the art to which this invention pertains. The terms "comprising" or "including," or similar words used in the embodiments of this invention, mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0048] With the deployment of 5G networks, the surge in IP traffic, and the rise of cloud computing and video-on-demand, optical networks face continuous growth pressure. However, the dynamic and uncertain nature of IP services themselves increases the difficulty of resource orchestration; services aggregated at the edge exhibit high burstiness and high transientity. Furthermore, in traditional network architectures, the IP layer and optical layer are independent, leading to significant waste of bandwidth resources and a sharp increase in operational complexity. Against this backdrop, the "IP + Optical" network architecture has emerged. With its superior network topology adjustment and end-to-end coordination capabilities, it has become the ideal choice for upgrading traditional networks to advanced network architectures capable of adapting to complex service needs. IP and optical synergy is a product of the continuous integration of IP and optical technologies. IP and optical synergy control enables intelligent management, rational resource utilization, and adaptation to highly dynamic service demands, representing a significant trend in future network architectures.

[0049] Traditional Wavelength Division Multiplexing (WDM) optical networks allocate spectrum resources using a fixed grid, resulting in waste in low-bandwidth services and further exacerbating this waste by requiring multiple wavelength channels and reserved guard bandwidth for high-bandwidth services. More importantly, this fixed-grid allocation strategy is ill-suited to the dynamic demands of new data services. Given these limitations of traditional WDM optical networks, Electronic Optical Networking (EON) was developed. Based on Orthogonal Frequency Division Multiplexing (OFDM) technology, EON subdivides the spectrum resources in the optical network into smaller frequency slot units. These slot units can be flexibly combined to achieve efficient spectrum resource allocation. Compared to the fixed-grid spectrum allocation strategy of WDM optical networks, EON's flexible allocation method better handles dynamic data service requests and significantly improves spectrum resource utilization.

[0050] When executing spectrum allocation algorithms for each service, the network must pre-consider certain constraints, including spectrum continuity, spectrum consistency, and spectrum non-overlap. Spectrum continuity requires that the spectrum blocks allocated to services consist of continuous frequency slots, thus fully utilizing spectrum resources while avoiding spectrum fragmentation. Spectrum consistency requires that the spectrum resources on the fiber optic links traversed by the service be identical, avoiding both redundant spectrum bandwidth allocation and mutual interference between signals. Spectrum non-overlap requires that frequency slots on the link cannot be shared by multiple services to prevent mutual interference between different services. If the spectrum bandwidth used by different services overlaps, it will cause spectral superposition interference, severely affecting the reliability of signal transmission.

[0051] The First Fit (FF) strategy first assigns index values ​​to the spectrum resources in the link sequentially. When selecting spectrum blocks that meet the service transmission requirements, it searches by index value from smallest to largest. If a spectrum block that meets the service bandwidth requirements is found, it is used to transmit the service; otherwise, it is determined that there are no suitable spectrum resources on the path. The Random Fit (RF) strategy, compared to the FF strategy, does not search by index value from smallest to largest. Instead, it traverses all consecutive idle spectrum blocks in the path link that can meet the number of frequency slots required by the service, puts these spectrum blocks into a set, and finally randomly selects one from the set to allocate to the service for transmission.

[0052] In EON, although its flexible spectrum allocation mechanism offers significant advantages in responding to dynamic changes in services, it is still constrained by the continuity of spectrum allocation during the actual dynamic establishment and disconnection of service links. This inevitably leads to spectrum fragmentation during frequent service adjustments. These fragments are difficult to align along the optical path, resulting in the network being unable to effectively utilize these resources even when there are a large number of idle frequency slots. When link spectrum resources cannot meet service bandwidth requirements, network congestion occurs, which not only reduces spectrum utilization efficiency but also seriously affects network performance. Therefore, how to rationally allocate spectrum resources to effectively reduce spectrum fragmentation has become a key issue in network resource management.

[0053] In related research, most studies focus solely on path selection considerations, with relatively little attention paid to spectrum allocation. For example, some researchers have proposed a joint evaluation method based on failure probability and fiber link load balancing. This method selects the path with the minimum combined weight by comparing the failure probability and fiber link load balancing values ​​of candidate paths. Others have proposed an RSA algorithm based on failure rate and spectrum occupancy rate, which selects the path with the minimum combined weight by comparing the failure rate and spectrum occupancy rate of candidate paths. However, even after reasonable path deployment, the spectrum allocation phase still requires adherence to resource allocation constraints to ensure signal transmission quality and avoid resource conflicts. This inevitably generates a series of spectrum fragments of varying sizes. These fragments not only reduce the utilization rate of network spectrum resources but also affect subsequent services, ultimately leading to network congestion.

[0054] In view of this, this invention proposes a routing and resource allocation method for minimizing spectrum fragmentation in "IP+optical" networks. In the path selection phase, K paths are carefully selected from the candidate paths to form a candidate path set for service allocation. During this process, the optimal path set is selected using the key indicator of spectrum resource reachability, thereby significantly increasing the probability of successful establishment of the working path. Successful establishment of the working path is the foundation for subsequent resource allocation operations. In the spectrum allocation phase, firstly, idle contiguous spectrum blocks that meet service requirements are selected from the candidate path set determined in the path selection phase for allocation of service requests. Subsequently, the frequency block concentration is calculated, which reflects the tightness between a frequency block and an already occupied frequency block. The closer a frequency block is to the used spectrum resource, the more effectively the gap between them after spectrum allocation, i.e., spectrum fragmentation, is reduced. Next, the weight value of the frequency block is calculated, which reflects the degree of impact of spectrum allocation on network resources before and after linking, i.e., the capacity of the frequency block to carry services. Finally, by calculating the spectrum placement deviation between different frequency blocks, the frequency block with the smallest value is selected for service allocation. This solution not only effectively integrates network resources but also reduces the generation of spectrum fragmentation, thereby significantly reducing network congestion rate. The following are the specific details of an embodiment of this invention.

[0055] like Figure 1 As shown, this embodiment of the invention provides a routing resource allocation method for minimizing network spectrum fragmentation, including a path selection phase and a spectrum allocation phase: The path selection phase aims to maximize path resource utilization by acquiring optical network topology information and screening the optimal path by quantifying the spectral resource availability and concentration of links and paths, thus forming a candidate path set. The spectrum allocation phase aims to minimize spectrum fragmentation and reduce service congestion. It converts IP services into optical layer slot requirements, selects consecutive idle spectrum blocks that meet the spectrum constraints from the candidate path set to form a frequency block candidate set, and determines the optimal frequency block and completes service allocation by quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources. After allocation, the link slot usage status is updated in real time.

[0056] In this embodiment, during the path selection phase, the optimal path is screened by quantifying the availability and concentration of spectrum resources of links and paths to form a candidate path set, specifically including: S11: Calculate the weighted spectrum resource reachability (SRA) of each link in all candidate paths. The weighted spectrum resource reachability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows:

[0057] In the formula, For link Spectrum resource reachability on the link, FS is the link. The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive idle spectrum blocks. The SRA needs to reflect both availability and concentration; the formula uses the structure of consecutive idle slot correlation statistics / total number of slots. (Idle is 1, occupied is 0) and The product of these terms is 1 only when both adjacent slots are idle, otherwise it is 0. Summing these terms allows us to count the number of associations among consecutive idle slots in the link, indirectly reflecting the concentration of idle slots. The longer the consecutive idle periods, the more associations occur, and the larger the numerator becomes; the denominator... Used for normalization to ensure that SRA values ​​of links of different lengths can be compared horizontally.

[0058] S12: Calculate the path SRA of the candidate path based on the weighted spectrum resource reachability (SRA) of each link. The calculation method is as follows:

[0059] In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on the path. The path consists of multiple links connected in series. Spectrum allocation must satisfy the requirement that all links have consecutive idle frequency blocks (spectrum consistency constraint). Therefore, the resource adaptability of the path depends on the SRA value of the weakest link. However, simply taking the minimum value will ignore the contribution of other links. Using the arithmetic mean of the sum of link SRAs / number of links can comprehensively reflect the resource status of all links on the path. This avoids the excessive impact of a single weak link and reflects the overall resource level, ensuring the comprehensiveness of path selection.

[0060] S13: According to the K-MSRA algorithm, sort the candidate paths in descending order of their SRA values, and select the first K non-intersecting paths to form a candidate path set. .

[0061] Specifically, in the K-MSRA algorithm, K represents the number of candidate paths. Setting the K value avoids the low fault tolerance problem of a single optimal path in traditional technologies. If only one path is selected, the service will be directly blocked if the spectrum resources of that path are occupied or fail. Selecting K paths provides redundancy and improves the reliability of service carrying. Paths are sorted in descending order of SRA value, prioritizing paths with strong resource adaptability to ensure that all paths in the candidate path set are high-quality paths, avoiding the inclusion of paths with scattered resources and low allocation success rates, thus guaranteeing the "quality" of the candidate set.

[0062] Link non-intersection refers to the absence of shared links between multiple paths. Its design aims to avoid path resource contention. If two candidate paths share a link, both paths become unusable when that link's spectrum is occupied, reducing the actual utility of the candidate set. Link non-intersection ensures the resource independence of each candidate path, maximizing the selection value of the candidate set and improving the flexibility of subsequent spectrum allocation. Candidate path set Its function is to provide sufficient high-quality path selection for the spectrum allocation stage, so that spectrum allocation is not limited to a single path, but can select the optimal frequency block from multiple high-quality paths, thereby further reducing the blocking rate.

[0063] In this embodiment, during the spectrum allocation phase, when converting IP services into optical layer bandwidth requirements, the number of bandwidths required for the service is calculated. The calculation method is as follows:

[0064] In the formula, For business The data transmission rate reflects the core bandwidth requirements of the business and is the basic input for computation; For the first nThe unit capacity of a frequency slot under a certain modulation type. The frequency slot capacity varies for different modulation formats (such as QPSK and 16QAM). Introducing this parameter enables dynamic adaptation, allowing the network to select the modulation format based on the real-time link status, making frequency slot utilization more flexible. The protection interval for service transmission is used to isolate the spectrum of adjacent services, avoid crosstalk between signals, and ensure transmission reliability. It is an indispensable fault-tolerant design in spectrum allocation. Indicates to Rounding. Because a frequency slot is the smallest indivisible allocation unit, if the calculation result is a decimal, it needs to be rounded up to 3 frequency slots to meet the service bandwidth requirements.

[0065] In this embodiment, the spectrum constraints include spectrum continuity, spectrum consistency, and spectrum non-overlap constraints: the spectrum continuity constraint limits the spectrum blocks allocated to services to consist of continuous frequency slots; the spectrum consistency constraint limits the spectrum resources allocated on all optical fiber links traversed by the service to be the same; and the spectrum non-overlap constraint limits the frequency slots on the same link to not be occupied by multiple services simultaneously.

[0066] Specifically, if the allocated frequency slots are discontinuous, it will directly generate idle fragments in the middle, and subsequent services will find it difficult to utilize these scattered fragments. Furthermore, optical layer transmission equipment only supports modulation and demodulation of continuous frequency slots; discontinuous frequency slots cannot achieve signal transmission. Therefore, spectrum continuity constraints are fundamental to avoiding fragmentation and ensuring transmission. Service transmission requires passing through multiple serial links. If the spectrum resources allocated to each link are different (e.g., link 1 uses frequency slots 1-3, link 2 uses frequency slots 4-6), the signal needs to be remodulated during link switching, which not only increases latency and energy consumption but also easily leads to signal distortion. Unifying the spectrum resources of each link enables seamless end-to-end signal transmission, improving transmission efficiency and reliability. If the same frequency slot is occupied by multiple services on the same link, it will generate severe spectrum superposition interference, causing the signal to be unable to be demodulated correctly. Spectrum non-overlap constraints are essentially "exclusive allocation of spectrum resources," ensuring that the spectrum resources for each service are independent and avoiding conflicts.

[0067] In this embodiment, during the spectrum allocation phase, the closeness between frequency blocks and already occupied resources is quantified through frequency block aggregation. The calculation method is as follows:

[0068]

[0069] In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration.

[0070] Specifically, spectrum fragments are idle frequency slots scattered among occupied frequency blocks. Therefore, if the newly allocated frequency blocks can be made as close as possible to the occupied resources, the size of the newly added gaps can be minimized. For example, if the occupied frequency blocks are in frequency slots 5-7, frequency slots 3-5 are closer than frequency slots 1-3, resulting in only one fragment in frequency slot 4. CD The value is a quantification of this "proximity". CD The larger the value, the closer the frequency block is to the occupied resources, and the fewer fragments are generated.

[0071] In this embodiment, during the spectrum allocation phase, the impact of frequency block deployment on link resources is quantified by frequency block weight values. The calculation process includes: S211: Calculate the initial weight of the link, using the following formula:

[0072] In the formula, For link The m-th free spectrum block, For link The number of frequency slots contained in the m-th spectral block. For link The number of free spectrum blocks. For link The weight value is calculated as follows: The more idle spectrum blocks a link has, and the smaller each individual idle spectrum block is, the higher the degree of link fragmentation. This method quantifies this fragmentation level; the smaller the individual idle spectrum block, the larger this value. The sum of these values ​​results in the link weight. The larger the value, the more severe the current fragmentation of the link.

[0073] S212: Perform difference normalization on the initial link weights to obtain the frequency block weight values, using the following formula:

[0074]

[0075] In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle jAfter one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block. Only the weight difference before and after deployment is calculated. It is impossible to compare the frequency block impact of different links horizontally (because the initial weights of different links may differ significantly), so dividing by... Normalize (the maximum possible weight value) to make Within a uniform magnitude (-1 to 1), the impact of different links and frequency blocks can be compared.

[0076] In this embodiment, the process of determining the optimal frequency block and completing service allocation in the spectrum allocation phase specifically includes: S221: Calculate the link spectrum configuration deviation (SAD) for each frequency block. The SAD is the product of the frequency block concentration (CD) and the frequency block weight (W) of the corresponding frequency block. The CD value only reflects the closeness between the frequency block and the occupied resources (the potential risk of fragmentation), and the W value only reflects the degree of impact of frequency block allocation on the link. Using either indicator alone has limitations. For example, a frequency block with a high CD value but a positive W value may be close to occupied resources but will exacerbate fragmentation. Multiplying the two together can achieve a "comprehensive evaluation in two dimensions". Only when the CD value is high (few fragments) and the W value is small (small impact on the link) will the SAD value be small, and the frequency block will be the optimal choice.

[0077] S222: Calculate the path SAD for each frequency block using the following method:

[0078] In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middle j Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on the path. Service transmission needs to pass through all links on the path. A small SAD value on only one link is not enough to guarantee the overall allocation effect. The SAD values ​​of all links need to be combined to reflect the overall performance of the frequency block on the entire path. An arithmetic average method is used to balance the influence of each link and avoid the extreme value of a single link dominating the evaluation result.

[0079] S223: Select the frequency block with the smallest path SAD value for service allocation; if multiple frequency blocks have the same path SAD value, use the first-match FF algorithm to select the frequency block according to the frequency slot index value from smallest to largest. The SAD value is a comprehensive quantitative result of the risk of frequency block fragmentation and the degree of link impact. Selecting the frequency block with the smallest SAD value can fundamentally achieve the goal of minimizing fragmentation and reducing the blocking rate, which is the optimal decision in the spectrum allocation stage.

[0080] When multiple frequency blocks have the same SAD value, it indicates that these frequency blocks have consistent overall adaptability. In this case, no complex calculations are needed. A simple and efficient first-matching algorithm (selecting from the smallest to the largest slot index) can be used to improve allocation efficiency while ensuring allocation effectiveness, avoiding increased service latency due to complex decision-making. This approach ensures both optimal allocation effectiveness and efficiency, achieving a balance between performance and efficiency, and meeting the requirements of highly dynamic services for low latency and high reliability in the network.

[0081] The method of the present invention will be described in detail below through an example. Consider a five-node network topology from A to E, and given a service request R(A, C, 75), as follows... Figure 2 As shown, the letters between two nodes represent links on that node, such as af; Figure 3 This describes the usage of frequency slots in the link AF, with the color-coded sections indicating that the frequency slots are occupied.

[0082] The path selection phase is as follows: Step 1: Calculate the reachability of the link spectrum resources on the alternative paths. Based on the Weighted Spectrum Resource Reachability (SRA) calculation formula, obtain... SRA l In this embodiment, there are three alternative paths from A to D, consisting of ABC, AEC, and ADC respectively. The values ​​of the two links on path ABC are (a) 1 / 3 and (b) 4 / 15; the values ​​of the two links on path AEC are (c) 4 / 15 and (d) 1 / 3; and the values ​​of the two links on path ADC are (e) 4 / 15 and (f) 1 / 3. Taking link (a) 1 / 3 as an example:

[0083] Step 2: Calculate the path spectrum resource reachability (SRA) on the candidate paths. Based on the path SRA calculation formula for the candidate paths, obtain... Since path selection is not a primary concern in this embodiment, the link frequency slot settings are identical across all three paths. The value is 0.3 for path ABC, 0.3 for path AEC, and 0.3 for path ADC. The three candidate paths are distinguished by their intermediate nodes, namely paths with intermediate nodes B, E, and D. For example, the value of 0.3 for path ABC is shown below:

[0084] Step 3: Since the candidate path values ​​calculated in Step 2 are the same, the K-MSRA algorithm selects three non-intersecting paths, ABC, AEC, and ADC, and puts them into the candidate path set PK as the working path candidate set for service allocation.

[0085] Spectrum allocation phase: Step 4: Calculate the number of frequency slots required for the service and determine whether there are frequency blocks in the candidate path set PK that can meet the service requirements based on the service requirements. The required number of frequency slots is calculated using the formula. as well as B cnt In this embodiment, no guard bandwidth is set. When the service request R(A, C, 75) arrives, a bandwidth of 25GHz under the QPSK modulation format is selected. Therefore, it can be concluded that this business requirement occupies 3 frequency slots.

[0086] It is not difficult to see that there are frequency blocks in the candidate path set PK that can meet the service requirements. However, since the spectrum allocation stage also needs to meet the constraints of spectrum consistency, spectrum continuity, and spectrum non-overlap, therefore... B cnt The frequency blocks in the middle are composed of { , , , , , The six frequency blocks are composed of frequency blocks 1-6 in sequence.

[0087] Step 5: Calculate the candidate set of frequency blocks B cnt The frequency block concentration on the link. Based on the formula for the density of frequency blocks and occupied resources, the following is calculated: The value of frequency block (a, 1) on link a is 1 / 7; the value of frequency block (a, 2) on link a is 1 / 14; the value of frequency block (b, 1) on link b is 1 / 7; the value of frequency block (b, 2) on link b is 1 / 14; the value of frequency block (c, 3) on link c is 1 / 14; the value of frequency block (c, 4) on link c is 1 / 14; the value of frequency block (d, 3) on link d is 1 / 14; the value of frequency block (d, 4) on link d is 1 / 14; the value of frequency block (e, 5) on link e is 1 / 14; the value of frequency block (e, 6) on link e is 1 / 7; the value of frequency block (f, 5) on link f is 1 / 14; the value of frequency block (f, 6) on link f is 1 / 7. For example, the value of frequency block (a, 1) on link a is 1 / 7.

[0088] Step 6: Calculate the candidate set of frequency blocks B cnt The frequency block weight value on the link is calculated using the formula. The value of frequency block (a, 1) on link a is 3 / 40; the value of frequency block (a, 2) on link a is 3 / 40; the value of frequency block (b, 1) on link b is 3 / 40; the value of frequency block (b, 2) on link b is 3 / 40; the value of frequency block (c, 3) on link c is -1 / 16; the value of frequency block (c, 4) on link c is -1 / 16; the value of frequency block (d, 3) on link d is -1 / 16; the value of frequency block (d, 4) on link d is 3 / 40; the value of frequency block (e, 5) on link e is 3 / 40; the value of frequency block (e, 6) on link e is 3 / 40; the value of frequency block (f, 5) on link f is 1 / 24; the value of frequency block (f, 6) on link f is 5 / 24. Taking frequency block (a, 1) on link a as an example with a value of 3 / 40:

[0089] The smaller the frequency block weight value obtained here, the better. A negative weight means that the current frequency block can perfectly adapt to the service requirements after carrying the service, without generating additional spectrum fragments or wasting spectrum resources on the link. This effectively reduces service blocking caused by spectrum resource waste and greatly reduces the service blocking rate.

[0090] Step 7: Calculate the candidate set of frequency blocks B cnt The spectral configuration deviation of the frequency block on the path. Based on the path SAD calculation formula for the frequency block, the following is obtained: The value of frequency block (B, 1) on path ABC is 0.01071; the value of frequency block (B, 2) on path ABC is 0.00536; the value of frequency block (E, 3) on path AEC is -0.00446; the value of frequency block (E, 4) on path AEC is 0.00045; the value of frequency block (D, 5) on path ADC is 0.00417; and the value of frequency block (D, 6) on path ADC is 0.02024. The three candidate paths are distinguished by their intermediate nodes, namely paths with B, E, and D as intermediate nodes. For example, frequency block (B, 1) on path ABC has a value of 0.01071:

[0091] Step 8: Calculate the SAD values ​​of all frequency blocks in Bcnt using the values ​​from Step 7. Therefore, when a service request R(A,C, 75) arrives, the frequency block on path AEC will be used preferentially. Used for service allocation. When this frequency block is used for service allocation, it first makes the spectrum resources in the current network more concentrated and closer to larger occupied frequency blocks, while avoiding the generation of additional spectrum fragmentation. This will facilitate the network's establishment of subsequent service connections. The value is higher than The advantage of this method lies in its prioritization of frequency blocks closer to already occupied spectrum resources. This minimizes spectrum fragmentation and considers proximity to existing resources. When there are many slots in a link, choosing blocks closer to already occupied resources ensures smooth service establishment even with some fragmentation. Conversely, establishing service on blocks further away from already occupied resources, while seemingly avoiding large spectrum fragmentation, actually creates many smaller slots between larger occupied blocks. These smaller slots are often unusable due to insufficient size to meet most service demands, resulting in significant resource waste. Therefore, prioritizing blocks closer to already occupied resources not only reduces spectrum fragmentation but also improves overall spectrum resource utilization, ensuring efficient resource use. Specifically, when multiple frequency blocks have the same SAD value, the network uses the FF algorithm for resource allocation to ensure orderly service delivery.

[0092] It should be noted that the method of this embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this embodiment, and these multiple devices will interact with each other to complete the method for limiting the storage space of mobile micro-applications.

[0093] It should be noted that the above description describes some embodiments of the present invention. In some cases, the described actions or steps can be performed in a different order than that shown in the above embodiments and the desired result can still be achieved. Furthermore, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] See Figure 4 Based on the same inventive concept, embodiments of the present invention also provide a routing resource allocation device for minimizing network spectrum fragmentation, comprising: The path selection module 100 is used to obtain optical network topology information with the goal of maximizing path resource utilization, and to filter the optimal path by quantifying the spectrum resource availability and concentration of links and paths to form a candidate path set. The spectrum allocation module 200 is used to convert IP services into optical layer frequency slot requirements with the goal of minimizing spectrum fragmentation and reducing service congestion rate. It selects continuous idle spectrum blocks that meet the spectrum constraints in the candidate path set to form a frequency block candidate set. By quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources, it determines the optimal frequency block and completes the service allocation. After allocation, it updates the link frequency slot usage status in real time.

[0095] In this embodiment, the path selection module 100 includes: The link SRA calculation submodule 101 is used to calculate the weighted spectrum resource reachability (SRA) of each link in all candidate paths. The weighted spectrum resource reachability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows:

[0096] In the formula, For link Spectrum resource availability FS For link The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive free spectrum blocks; The path SRA calculation submodule 102 calculates the path SRA of candidate paths based on the weighted spectrum resource reachability SRA of each link. The calculation method is as follows:

[0097] In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on; K-MSRA path filtering submodule 103 is used to sort the candidate paths in descending order of their SRA values ​​according to the K-MSRA algorithm, and select the first K non-intersecting paths to form a candidate path set. .

[0098] In this embodiment, the spectrum allocation module 200 calculates the number of frequency slots required for the service when converting IP services into optical layer frequency slot requirements. The calculation method is as follows:

[0099] In the formula, For business Data transmission rate, For the first n The unit capacity of the frequency slot under each modulation type For the protection interval of service transmission, Indicates to Round down.

[0100] In this embodiment, the spectrum allocation module 200 includes spectrum continuity, spectrum consistency, and spectrum non-overlapping constraints: The spectrum continuity constraint requires that the spectrum blocks allocated to services consist of continuous frequency slots; The spectrum consistency constraint requires that the spectrum resources allocated on all optical fiber links through which the service passes be the same. The spectrum non-overlap constraint stipulates that a frequency slot on the same link cannot be occupied by multiple services simultaneously.

[0101] In this embodiment, the spectrum allocation module 200 quantifies the closeness between frequency blocks and occupied resources through frequency block centralization. The calculation method is as follows:

[0102]

[0103] In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration.

[0104] In this embodiment, the spectrum allocation module 200 further includes: Link initial weight calculation submodule 201 is used to calculate the link initial weight, and the formula is:

[0105] In the formula, For link Upper m A free spectrum block For link Upper m The number of frequency slots contained in a spectrum block For link The number of free spectrum blocks. For link The weight value; Normalization processing submodule 202 is used to perform difference normalization processing on the initial link weights to obtain the frequency block weight values, using the following formula:

[0106]

[0107] In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle j After one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block; The link SAD calculation submodule 203 is used to calculate the link spectrum configuration deviation SAD of each frequency block. The spectrum configuration deviation SAD is the product of the frequency block concentration CD and the frequency block weight value W of the corresponding frequency block. The path SAD calculation submodule 204 is used to calculate the path SAD of each frequency block in the following way:

[0108] In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middle j Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on; The service allocation submodule 205 is used to select the frequency block with the smallest path SAD value for service allocation; if there are multiple frequency blocks with the same path SAD value, the first matching FF algorithm is used to select the frequency block according to the frequency slot index value from smallest to largest.

[0109] The apparatus described above is used to implement the routing resource allocation method for minimizing network spectrum fragmentation in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0110] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the routing resource allocation method for minimizing network spectrum fragmentation as described in any of the above embodiments.

[0111] Figure 5 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 310, a memory 320, an input / output interface 330, a communication interface 340, and a bus 350. The processor 310, memory 320, input / output interface 330, and communication interface 340 are interconnected internally via the bus 350.

[0112] The processor 310 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0113] The memory 320 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 320 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 320 and is called and executed by the processor 310.

[0114] Input / output interface 330 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touch screens, microphones, various sensors, etc., and output devices may include displays, speakers, vibrators, indicator lights, etc.

[0115] The communication interface 340 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0116] Bus 350 includes a pathway for transmitting information between various components of the device, such as processor 310, memory 320, input / output interface 330, and communication interface 340.

[0117] It should be noted that although the above-described device only shows the processor 310, memory 320, input / output interface 330, communication interface 340, and bus 350, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0118] The electronic devices described above are used to implement the routing resource allocation method for minimizing network spectrum fragmentation in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0119] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, the present invention also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the routing resource allocation method for minimizing network spectrum fragmentation as described in any of the above embodiments.

[0120] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0121] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the routing resource allocation method for minimizing network spectrum fragmentation as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0122] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of the invention as described above, which are not provided in detail for the sake of brevity.

[0123] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of the invention, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of the invention, and this also takes into account the fact that the details of implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of the invention will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of the invention, it will be apparent to those skilled in the art that the embodiments of the invention may be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0124] Although the invention has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., DRAM) may use the embodiments discussed.

[0125] The embodiments of this invention are intended to cover all such substitutions, modifications, and variations falling within the scope of the claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this invention should be included within the scope of protection of this invention.

Claims

1. A routing resource allocation method for minimizing network spectrum fragmentation, characterized in that, Includes the path selection phase and the spectrum allocation phase: The path selection phase aims to maximize path resource utilization by acquiring optical network topology information and screening the optimal path by quantifying the spectral resource availability and concentration of links and paths, thus forming a candidate path set. The spectrum allocation phase aims to minimize spectrum fragmentation and reduce service congestion. It converts IP services into optical layer slot requirements, selects consecutive idle spectrum blocks that meet the spectrum constraints from the candidate path set to form a frequency block candidate set, and determines the optimal frequency block and completes service allocation by quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources. After allocation, the link slot usage status is updated in real time.

2. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 1, characterized in that, In the path selection phase, the optimal path is screened by quantifying the spectrum resource availability and concentration of links and paths, forming a candidate path set, specifically including: S11: Calculate the weighted spectrum resource reachability (SRA) of each link in all candidate paths. The weighted spectrum resource reachability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows: ； In the formula, For link Spectrum resource availability FS For link The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive free spectrum blocks; S12: Calculate the path SRA of the candidate path based on the weighted spectrum resource reachability (SRA) of each link. The calculation method is as follows: ； In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on; S13: According to the K-MSRA algorithm, sort the candidate paths in descending order of their SRA values, and select the first K non-intersecting paths to form a candidate path set. .

3. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 1, characterized in that, During the spectrum allocation phase, when converting IP services into optical layer bandwidth requirements, the number of bandwidths required for the service is calculated. The calculation method is as follows: ； In the formula, For business Data transmission rate, For the first n The unit capacity of the frequency slot under each modulation type For the protection interval of service transmission, Indicates to Round down.

4. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 1, characterized in that, The spectral constraints include constraints on spectral continuity, spectral consistency, and spectral non-overlap. The spectrum continuity constraint requires that the spectrum blocks allocated to services consist of continuous frequency slots; The spectrum consistency constraint requires that the spectrum resources allocated on all optical fiber links through which the service passes be the same. The spectrum non-overlap constraint stipulates that a frequency slot on the same link cannot be occupied by multiple services simultaneously.

5. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 1, characterized in that, During the spectrum allocation phase, the closeness between frequency blocks and already occupied resources is quantified through frequency block aggregation. The calculation method is as follows: ； ； In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration.

6. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 1, characterized in that, In the spectrum allocation phase, the impact of frequency block deployment on link resources is quantified by frequency block weight values. The calculation process includes: S211: Calculate the initial weight of the link, using the following formula: ； In the formula, For link Upper m A free spectrum block For link Upper m The number of frequency slots contained in a spectrum block For link The number of free spectrum blocks. For link The weight value; S212: Perform difference normalization on the initial link weights to obtain the frequency block weight values, using the following formula: ； ； In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle j After one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block.

7. The routing resource allocation method for minimizing network spectrum fragmentation according to claim 5 or 6, characterized in that, In the spectrum allocation phase, the process of determining the optimal frequency block and completing service allocation specifically includes: S221: Calculate the link spectrum configuration deviation SAD for each frequency block, wherein the spectrum configuration deviation SAD is the product of the frequency block concentration CD and the frequency block weight value W of the corresponding frequency block; S222: Calculate the path SAD for each frequency block using the following method: ； In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middle j Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on; S223: Select the frequency block with the smallest path SAD value for service allocation; if there are multiple frequency blocks with the same path SAD value, use the first matching FF algorithm to select the frequency block according to the frequency slot index value from smallest to largest.

8. A routing resource allocation device for minimizing network spectrum fragmentation, characterized in that, include: The path selection module is used to obtain optical network topology information with the goal of maximizing path resource utilization, and to filter the optimal path by quantifying the spectral resource availability and concentration of links and paths to form a candidate path set; The spectrum allocation module is used to convert IP services into optical layer frequency slot requirements with the goal of minimizing spectrum fragmentation and reducing service congestion rate. It selects continuous idle spectrum blocks that meet the spectrum constraints in the candidate path set to form a frequency block candidate set. By quantifying the closeness between the frequency block and the occupied resources and the impact of frequency block deployment on link resources, it determines the optimal frequency block and completes the service allocation. After allocation, it updates the link frequency slot usage status in real time.

9. The routing resource allocation device for minimizing network spectrum fragmentation according to claim 8, characterized in that, The path selection module includes: The Link SRA Calculation Submodule is used to calculate the Weighted Spectrum Resource Availability (SRA) of each link in all candidate paths. The Weighted Spectrum Resource Availability (SRA) reflects the availability and resource concentration of idle frequency slots on the link. The calculation method is as follows: ； In the formula, For link Spectrum resource availability FS For link The set of frequency gaps on, For link The total number of frequency slots on the surface This refers to the link bandwidth occupancy status. This refers to the distribution of idle frequency slots in the link, i.e., the link's idle frequency slot distribution. The relative size of consecutive free spectrum blocks; The path SRA calculation submodule calculates the path SRA of candidate paths based on the weighted spectrum resource reachability SRA of each link. The calculation method is as follows: ； In the formula, For path Spectrum resource availability For path The set of links on, For path The number of links on; The K-MSRA path selection submodule is used to sort the candidate paths in descending order of their SRA values ​​according to the K-MSRA algorithm, and select the first K non-intersecting paths to form a candidate path set. .

10. The routing resource allocation apparatus for minimizing network spectrum fragmentation according to claim 8, characterized in that, In the spectrum allocation module, when converting IP services into optical layer bandwidth requirements, the number of bandwidths required for the service is calculated. The calculation method is as follows: ； In the formula, For business Data transmission rate, For the first n The unit capacity of the frequency slot under each modulation type For the protection interval of service transmission, Indicates to Rounding; In the spectrum allocation module, the spectrum constraints include constraints on spectrum continuity, spectrum consistency, and spectrum non-overlap. The spectrum continuity constraint requires that the spectrum blocks allocated to services consist of continuous frequency slots; The spectrum consistency constraint requires that the spectrum resources allocated on all optical fiber links through which the service passes be the same. The spectrum non-overlap constraint stipulates that a frequency slot on the same link cannot be occupied by multiple services simultaneously. In the spectrum allocation module, the closeness between frequency blocks and occupied resources is quantified through frequency block centralization. The calculation method is as follows: ； ； In the formula, For path The set of all consecutive idle frequency blocks that meet business requirements. for The Middle j The distance between each free spectrum block and the largest occupied spectrum block The maximum frequency gap index number, The smallest frequency gap index number, for The Middle j A free spectrum block in the link Frequency block concentration on; The spectrum allocation module also includes: The initial link weight calculation submodule is used to calculate the initial link weight, using the following formula: ； In the formula, For link Upper m A free spectrum block For link Upper m The number of frequency slots contained in a spectrum block For link The number of free spectrum blocks. For link The weight value; The normalization processing submodule is used to perform difference normalization on the initial link weights to obtain the frequency block weight values, using the following formula: ； ； In the formula, For placement The Middle j Front link of one free spectrum block The weight value on, For placement The Middle j After one free spectrum block, the link The weight value on, This represents the weight value when idle and occupied frequency slots alternate. for The Middle j The weight values ​​of each idle spectrum block; The link SAD calculation submodule is used to calculate the link spectrum configuration deviation SAD of each frequency block. The spectrum configuration deviation SAD is the product of the frequency block concentration CD and the frequency block weight value W of the corresponding frequency block. The path SAD calculation submodule is used to calculate the path SAD of each frequency block in the following way: ； In the formula, for The Middle j Path spectrum configuration deviation of each idle spectrum block for The Middle j Link spectrum configuration deviation of each idle spectrum block for The Middle j A free spectrum block in the path The number of links on; The service allocation submodule is used to select the frequency block with the smallest path SAD value for service allocation; if there are multiple frequency blocks with the same path SAD value, the first matching FF algorithm is used to select the frequency block according to the frequency slot index value from smallest to largest.

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