CN108134967A - A kind of electric power optical-fiber network routing frequency spectrum distributing method and system - Google Patents

Abstract

The present invention relates to a method and system for allocating routing spectrum of an electric power optical network. When there is a power service connection allocation request in the electric power optical network, the available frequency spectrum index on each link in the electric power optical network is obtained; The available spectrum index, setting different spectrum window positions under different modulation formats to determine the candidate solution set of the service request that meets the corresponding distance requirement; selecting the modulation format and routing spectrum allocation that meet the preset rules from the candidate solution set. The routing modulation format spectrum allocation method can effectively reduce the total number of spectrum usage required in the network and improve the spectrum utilization rate under the premise of indirectly ensuring the transmission quality.

Description

A power optical network routing spectrum allocation method and system

technical field

The invention relates to the field of elastic optical fiber network for electric power communication, in particular to a method and system for allocating routing frequency spectrum of electric power optical network.

Background technique

With the continuous development of the power industry and the introduction of smart grids, the bandwidth requirements of power communication services continue to increase, and the types of services are diversified, which puts forward higher requirements for the optical communication network carried. In the traditional wavelength division multiplexing optical network, the fixed wavelength grid characteristic determines that the minimum switching granularity is the wavelength. Even if the bandwidth requested by the service only occupies part of the capacity of the wavelength channel, a complete wavelength channel must be allocated. Moreover, the power service information transmission granularity of the electric power communication optical transmission network is small and bursty, and the fixed coarse wavelength grid will lead to serious waste of spectrum. The elastic optical network uses optical orthogonal frequency division multiplexing technology to allow partial overlap of the optical channel spectrum and has a smaller spectrum granularity. It converts the wavelength channel of the traditional wavelength division multiplexing optical network into a frequency slot with a smaller granularity. It is one of the main technologies of next-generation optical network with great potential. In the elastic optical network, the required frequency slot can be allocated to each service with different requirements according to the service rate, so as to realize the flexible allocation of differentiated rate services, reduce the total network service blocking rate, and improve the utilization rate of spectrum resources.

In addition, the power backbone network has a large geographical span, and the business distribution is uneven and has different security level requirements, resulting in a wide range of changes in the length of the transmission path and transmission capacity of the bearing business. Existing studies have shown that elastic optical networks can flexibly allocate spectrum according to the data rate and transmission distance of service requests. A single frequency slot 12.5GHz using different modulation formats BPSK, QPSK, 8QAM, 16QAM can support a maximum transmission rate of 12.5Gb/s, 25Gb/s, 37.5Gb/s, 50Gb/s, and each modulation format can support a maximum The transmission distance is 9600km, 4800km, 2400km and 1200km. In order to adapt to a variety of power communication services in the future, the power communication elastic optical network must have a strong ability to optimize resource allocation. How to efficiently optimize resource allocation in the power communication network and solve routing and modulation format and spectrum assignment (Routing and Modulation, Spectrum Assignment, MRSA) problems has become a problem that needs to be solved urgently.

Contents of the invention

In view of the current situation that the geographical span of the power backbone network is relatively large and the business distribution is uneven, the purpose of the present invention is to provide a method and system for routing spectrum allocation in power optical networks. The present invention performs joint allocation of routing spectrum in a distance-adaptive modulation format get the optimal solution. The routing modulation format spectrum allocation method can effectively reduce the total number of spectrum usage required in the network under the premise of indirectly guaranteeing the transmission quality, and improve the spectrum utilization rate.

The object of the present invention is to adopt following technical scheme to realize:

The present invention provides a power optical network routing spectrum allocation method, the improvement of which is:

When there is a power service connection allocation request in the power optical network, obtain the available spectrum index on each link in the power optical network;

According to the available spectrum index on each link, different spectrum window positions are set under different modulation formats to determine the candidate solution sets of service requests that meet the corresponding distance requirements;

From the candidate solution set, the modulation format and routing frequency spectrum allocation conforming to preset rules are selected.

Further: the electric power service connection assignment request includes source node, destination node, service type and request rate information for service connection in the electric power optical network.

Further: before obtaining the available spectrum index on each link in the electric power optical network, it also includes:

Sort business requests based on business priority and request rate.

Further: the sorting of service requests according to service priority and request rate includes:

Real-time sensitive services have high priority, and non-real-time delay-sensitive services have low priority;

Among the services in the same priority, the higher the request rate, the higher the ranking.

Further: according to the available spectrum index on each link, setting different spectrum window positions under different modulation formats to determine the candidate solution set of the service request that meets the corresponding distance requirement includes:

According to the rate of the service request, different modulation formats are sequentially selected from high order to low order, and the number of transmission frequency slots required by the service under the different modulation formats is calculated;

Calculate the spectrum window set S according to the available spectrum index of the spectrum on each link and the number of service transmission frequency slots;

Sequentially select the spectral window s in the spectral window set S, s∈S;

Establish a virtual network topology, and use the k-shortest path algorithm in the virtual network topology to calculate the first k shortest paths between the source node and the destination node in the service request, and make the path length less than the transmission distance limit of the current order modulation format The path, its modulation format, and the spectral window s are stored in the candidate solution set of the service request until all the spectral windows in the spectral window set S are processed.

Further: the construction method of the spectral window set S includes:

For the service request that the number of required transmission frequency slots is n, S={[1,n],[2,n+1],...,[B-n+1,B]}; where, B is the fiber link The total number of spectrum resources on the road;

Further: the candidate solution set includes: a modulation distance-limited path, a modulation format corresponding to the modulation distance-limited path, and a set composed of a spectral window s.

Further: the formula for calculating the number of transmission frequency slots is: number of transmission frequency slots n=transmission rate/transmission rate of a single frequency slot in modulation format m.

Further: selecting a modulation format conforming to preset rules from the candidate solution set, including:

When the candidate solution set of the service is empty, set the next low-order modulation format, recalculate the number of transmission frequency slots required by the service under the set modulation format, and turn to the candidate solution of the service if the low-order modulation format is empty Set is not empty step.

Further: selecting a routing spectrum allocation conforming to preset rules from the candidate solution set, including:

If the candidate solution set of the service is not empty, calculate the total number of link spectrums used by each path in the candidate solution set, select a path with the least number, and return the corresponding spectrum window of the path, and end the search for the best route for the service request ; Reserve communication spectrum resources for the spectrum window position on each fiber optic link of the path.

Further: the total number of link spectrums=the number of optical fiber links*the number of required transmission frequency slots.

The present invention provides a power optical network routing spectrum distribution system, the improvement of which is:

The obtaining module is used to obtain the available spectrum index on each link in the electric power optical network when there is a power service connection allocation request in the electric power optical network;

A determining module, configured to set different spectral window positions under different modulation formats according to available spectrum indexes on each link to determine candidate solution sets of service requests that meet corresponding distance requirements;

An allocation module, configured to select a modulation format conforming to preset rules and route spectrum allocation from the candidate solution set.

Further: the electric power service connection assignment request includes source node, destination node, service type and request rate information for service connection in the electric power optical network.

Further: a sorting module is also included, which is used to sort the service requests according to the service priority and the request rate before the acquisition of the available frequency spectrum index on each link in the electric power optical network.

Further: the sorting module includes:

The prioritization unit is used for high priority for real-time sensitive services, and low priority for non-real-time delay-sensitive services;

The request rate sorting unit is used for services in the same priority, the higher the request rate, the higher the sorting.

Further: the determination module includes:

The first calculation unit is used to sequentially select different modulation formats from high order to low order according to the rate of the service request, and calculate the number of transmission frequency slots required by the service under the different modulation formats;

The second calculation unit is used to calculate the spectrum window set S according to the available spectrum index of each link spectrum and the number of service transmission frequency slots;

The selection unit is used to sequentially select the spectral window s in the spectral window set S, s∈S;

The establishment unit is used to establish a virtual network topology, and uses the k-shortest path algorithm to calculate the first k shortest paths between the source node and the destination node in the virtual network topology, and the path length is less than the transmission distance limit of the current order modulation format The path, its modulation format, and the spectral window s are stored in the candidate solution set of the service request until all the spectral windows in the spectral window set S are processed.

Further: the number of transmission frequency slots is expressed as: number of transmission frequency slots n=transmission rate/transmission rate of a single frequency slot in modulation format m.

Further: the allocation module includes:

The modulation format setting unit is used to set the next low-order modulation format when the candidate solution set of the service is empty, and recalculate the number of transmission frequency slots required by the service under the set modulation format. If the low-order modulation format has If it is empty, the candidate solution set for turning to the business is not an empty step;

The routing allocation unit is used to calculate the total number of link spectrums used by each path in the candidate solution set when the service candidate solution set is not empty, select and return a path with the least number, and its corresponding modulation format and spectrum window, End the search for the best route for service requests.

Compared with the closest prior art, the beneficial effects achieved by the technical solution provided by the present invention are:

1. The present invention includes obtaining the available spectrum index on each link in the power optical network when there is a power service connection allocation request in the power optical network; according to the available spectrum index on each link, under different modulation formats Set different spectral window positions to determine the candidate solution set of the service request that meets the corresponding distance requirements; select the modulation format and route spectrum allocation that meet the preset rules from the candidate solution set, which can effectively guarantee the transmission quality indirectly. Reduce the total number of spectrum usage required in the network and improve spectrum utilization.

2. Based on the multi-modulation format spectrum window routing spectrum allocation method for power optical networks, the power services of different levels are sorted first, and then the distance adaptive modulation format and routing spectrum are jointly allocated to obtain the optimal solution. The invention has the following advantages: the invention sorts the services of different priorities and different speeds first, and can avoid the rejection of high-priority services. The invention adopts a distance self-adaptive modulation format, fully considers the influence of geographical location on the power service, and indirectly ensures the transmission quality of the service. The present invention uses the size and position of the spectrum window to search for effective link resources in the current network, calculates the spectrum resource and uses the smallest path set and corresponding spectrum window as a candidate solution set.

Description of drawings

Fig. 1 is the flow chart of the power optical network routing spectrum allocation method provided by the present invention;

Fig. 2 is a schematic diagram of a six-node network of a specific embodiment provided by the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The following description and drawings illustrate specific embodiments of the invention sufficiently to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. The examples merely represent possible variations. Individual components and functions are optional unless explicitly required, and the order of operations may vary. Portions and features of some embodiments may be included in or substituted for those of other embodiments. The scope of embodiments of the present invention includes the full scope of the claims, and all available equivalents of the claims. These embodiments of the present invention may be referred to herein, individually or collectively, by the term "invention", which is for convenience only and is not intended to automatically limit the application if in fact more than one invention is disclosed The scope is any individual invention or inventive concept.

Embodiment one,

The present invention adopts the following technical solutions: a power optical network routing spectrum allocation method based on multi-modulation format spectrum windows, and the steps of the method are as follows:

1) Power service connection allocation request. The power service connection allocation request includes information on the source node, destination node, service type and request rate for service connection in the electric power communication elastic optical network;

2) Sorting and processing all business requests according to business priority and request rate;

3) Obtain the spectrum usage status of each link according to the network topology. Obtain the use of all spectrums on all links in the network topology and the total number of available spectrums;

4) According to the adjacency matrix of the network topology and the spectrum usage status on each link, set different spectrum window positions under different modulation formats to search for a service request candidate solution set that meets the corresponding distance requirement;

5) From all the candidate solutions obtained, select the one with the least total spectrum used to allocate the modulation format and routing spectrum for the power service;

6) According to the result, carry out the modulation format and routing spectrum allocation for the power service, and update the spectrum usage of all links in the network, return to step 3), and perform routing modulation format and spectrum allocation for the next business until all business requests All processed.

Based on the foregoing embodiments, in the step 2), the method for sorting and processing the business requests is as follows:

Sort according to the priority of service requests, the higher the priority is in the front of the queue; the services in the same priority are sorted according to the request rate, the higher the request rate is in the front of the queue. Update the queue of business requests.

Based on the above-mentioned embodiment, in the step 4) and step 5), the methods for calculating and selecting routing and modulation format and spectrum allocation are as follows:

(1) Process the business requests in the business queue sequentially;

(2) According to the rate of the service request, select modulation formats such as 16QAM, 8QAM, QPSK, and BPSK from high order to low order, and calculate the number of frequency slots required for the transmission service under this modulation format;

(3) Calculate the spectrum window set S according to the frequency spectrum usage status of each link obtained in the step 3) and the number of service transmission frequency slots;

(4) sequentially select the spectral window s∈S in the spectral window set S;

(5) Establishing a virtual network topology, copying the network structure in the network topology and the current frequency spectrum usage of each link to the virtual network topology. If the spectrum where the spectrum window s is located in the virtual network topology is unavailable, delete the link and update the virtual network topology.

(6) In the virtual network topology, use the k shortest path algorithm to calculate the first k shortest paths between the source node and the destination node, and store the path that meets the modulation distance limit and its corresponding modulation format and spectral window s into the A set of candidate solutions for business requests.

(7) If the spectrum window has not been processed yet, return to step (4) to process the next spectrum window. Otherwise, go to (8).

(8) If the candidate solution set of the service is empty, set the next low-order modulation format, and return to (2); if the low-order modulation format at this time is empty, proceed to (9).

(9) If the candidate solution set of the service is not empty, then from the candidate solution set of modulation format, routing path and spectrum window, calculate the total number of spectrums used by each path in the candidate solution set, select and return a path with the least number, And return the corresponding spectrum window of the path, and end the search for the best route of the request. If the candidate solution set of the service is empty, an invalid value is returned, and the best route search for the request ends. The communication spectrum resource is reserved for the spectrum window position on each fiber link of the path.

Based on the foregoing embodiment, in the step (2), the method for calculating the required number of frequency slots according to the service rate and the modulation format is as follows: for a certain request rs, d, n, L, wherein, s, d, n and L In turn, it indicates the source node, destination node, request rate and priority level. For 16QAM, 8QAM, QPSK, BPSK, the number of required frequency slots n=transmission rate/transmission rate of a single frequency slot under modulation format m.

Based on the above embodiment, in the step (3), the calculation method of the spectrum window set S is as follows: the spectrum window (Spectrum Window, SW) represents a continuous spectrum. For a service request with a required number of frequency slots of m, there are at most B-m+1 spectrum windows of length m that meet the requirements in the fiber resources, where B is the total number of spectrum resources on the fiber link.

Embodiment two,

The present invention provides a specific embodiment. The six-point network structure diagram is shown in FIG. 2. The present invention provides a power optical network routing spectrum allocation method based on multi-modulation format spectrum windows. The specific implementation steps are as follows:

(1) The incoming power service requests are R1 (1, 2, 100, L1), R2 (1, 4, 100, L2) and R3 (1, 6, 50, L2);

(2) Sorting and processing the power service requests. According to the main order of L1, L2, L3 business and the order of rate, the order from beginning to end in the three power service request queues is: R1 (1, 2, 100, L1), R2 (1, 4, 100, L2), R3 (1, 6, 50, L2);

(3) Obtain the spectrum usage status of each link according to the network topology structure. The total number of frequency slots in the current network G is 10, and each fiber has not been occupied when it is initialized, and the range of available frequency slot indices is [1, 10];

(4) According to the adjacency matrix of the network topology and the spectrum usage status on each link, search for the K shortest paths between the source node and the destination node that satisfy the service request by setting the spectrum window, and obtain the routing spectrum allocation solution set .

Handle the connection requesting R1. The highest-order modulation format 16QAM is selected, and the number of frequency slots required for transmission at this time is n=100/50=2. The spectrum window set S is {[1, 2], [2, 3], [3, 4], ..., [9, 10]}.

For the spectrum window sw=[1, 2], a virtual network topology G'=G is established, and edges in the network G' that cannot tolerate sw are deleted. After the update, the topological connection state of G' remains unchanged. The first three shortest paths in G' are calculated as 1-3-2 (600km), 1-2 (800km), and 1-3-5-4-2 (4300km). Remove the 1-3-5-4-2 (4300km) which does not conform to the longest transmission distance of the 16QAM modulation format, and store the other two paths in the candidate path set.

Similarly, the first three shortest paths whose spectral windows are [1, 2], [2, 3], [3, 4], ... [9, 10] are calculated and stored in the candidate path set.

Similarly, when the modulation formats are 8QAM, QPSK and BPSK respectively, the frequency spectrum window is traversed.

(5) From the candidate solution sets of all modulation formats and spectrum windows, select the one with the least total spectrum used to allocate the modulation format and routing spectrum for the power service. As shown in Table 1:

Table 1 Request some elements in the candidate path set of R1

In the set of candidate paths, select the path 1-2 (800km, sw=[1,2], m=4) that occupies the least number of frequency slots, and end the route selection.

(6) Allocation of modulation format and routing spectrum for power services based on the result, and update spectrum usage of all links in the network. Assign the routing spectrum path 1-2 (sw=[1, 2]) to the current network G, and the frequency slot resource of the link after assignment is shown in Table 2:

Table 2 Link resource status after request R1 is allocated

The next service request R2 (1, 4, 100, L2) is processed.

Return to step (4), select the modulation format 16QAM (m=4), and occupy the frequency slot as The spectrum window sw is [1, 2]. Among them, the three paths 1-3-2-4 (2300km), 1-3-5-4 (2600km), 1-3-5-6-4 (2900km) of the shortest path set do not meet the condition of transmission distance <1200km , the set of candidate routing paths has no elements. Continue to select the modulation format 16QAM (m=4), and when calculating the k shortest paths under the spectrum window sw=[2,3], [3,4],...[9,10], the element sets are all empty.

Return to step (4), select the modulation format 8QAM (m=3), and occupy the frequency slot as When the spectral window sw=[1,3], the elements of the newly added candidate path set are 1-3-2-4 (2300km), not 1-3-5-4 (2600km) and 1-3-5- 6-4 (2900km). When the spectrum window is sw=[2, 4], the elements in the newly added candidate path set are 1-3-2-4 (2300km), not 1-3-5-4 (2600km) and 1-3- 5-6-4 (2900km). When the spectrum window is sw=[3,5], the elements in the newly added candidate path set are 1-3-2-4 (2300km), not 1-2-4 (2500km), 1-3-5-4 (2600km). Finally, the path added to the candidate path set under 8QAM is 1-3-2-4 (2300km, sw=[1, 3]).

After continuing to select the modulation format QPSK and BPSK, the elements in the request (2) candidate path set are as shown in Table 3:

Table 3 Request some elements in the candidate path set of R2

Select the path with the least number of occupied frequency slots, 1-2-4 (2500km, sw=[3,6], m=2). After the routing spectrum allocation is completed, the link resources in the network are shown in Table 4 below:

Table 4 Link resource status after request R2 is allocated

When processing the (3)th service request R3 (1, 6, 50, L2), the occupied frequency slots are 1, 2, 2, 4 respectively. The spectrum set of candidate routes is shown in Table 5 below:

Table 5 Request some elements in the candidate path set of R3

Select the path with the least number of occupied frequency slots, 1-3-5-6 (2500km, sw=[1, 2], m=2). After the routing spectrum allocation is completed, the link resources in the network are shown in Table 6 below:

Table 6 Link resource status after allocating request R3

In each step of the implementation project, the idea of heuristic algorithm is adopted. After traversing and selecting modulation formats of different orders, the path that meets the transmission restrictions and occupies the least number of frequency slot resources is selected, and the heuristic algorithm is fast and approximate. optimal advantage.

Embodiment three,

Based on the same inventive concept, the present invention also provides a power optical network routing spectrum distribution system, including:

The obtaining module is used to obtain the available spectrum index on each link in the electric power optical network when there is a power service connection allocation request in the electric power optical network;

A determining module, configured to set different spectral window positions under different modulation formats according to available spectrum indexes on each link to determine candidate solution sets of service requests that meet corresponding distance requirements;

An allocation module, configured to select a modulation format conforming to preset rules and route spectrum allocation from the candidate solution set.

Further: the electric power service connection assignment request includes source node, destination node, service type and request rate information for service connection in the electric power optical network.

Further: a sorting module is also included, which is used to sort the service requests according to the service priority and the request rate before the acquisition of the available frequency spectrum index on each link in the electric power optical network.

Further: the sorting module includes:

The prioritization unit is used for real-time sensitive services with high priority, and for non-real-time time-delay-sensitive services with low priority;

The request rate sorting unit is used for services in the same priority, the higher the request rate, the higher the sorting.

Further: the determination module includes:

The first calculation unit is used to sequentially select different modulation formats from high order to low order according to the rate of the service request, and calculate the number of transmission frequency slots required by the service under the different modulation formats;

The second calculation unit is used to calculate the spectrum window set S according to the available spectrum index of each link spectrum and the number of service transmission frequency slots;

The selection unit is used to sequentially select the spectral window s in the spectral window set S, s∈S;

The establishment unit is used to establish a virtual network topology, and uses the k-shortest path algorithm to calculate the first k shortest paths between the source node and the destination node in the virtual network topology, and the path length is less than the transmission distance limit of the current order modulation format The path, its modulation format, and the spectrum window s are stored in the candidate solution set of the service request until all the spectrum windows in the spectrum window set S are processed.

Further: the number of transmission frequency slots is expressed as: number of transmission frequency slots n=transmission rate/transmission rate of a single frequency slot in modulation format m.

Further: the allocation module includes:

The modulation format setting unit is used to set the next low-order modulation format when the candidate solution set of the service is empty, and recalculate the number of transmission frequency slots required by the service under the set modulation format. If the low-order modulation format has If it is empty, the candidate solution set for turning to the business is not an empty step;

The routing allocation unit is used to calculate the total number of link spectrums used by each path of the candidate solution set when the service candidate solution set is not empty, select and return a path with the least number, and its corresponding modulation format and spectrum window, End the search for the best route for service requests.

The present invention aims at the current situation that the geographical span of the power backbone network is relatively large and the service distribution is uneven. The present invention first sorts the power services of different levels, and then performs joint allocation of routing spectrum in the distance-adaptive modulation format to obtain the optimal solution. . The routing modulation format spectrum allocation method can effectively reduce the total number of spectrum usage required in the network and improve the spectrum utilization rate under the premise of indirectly ensuring the transmission quality.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify or equivalently replace the specific embodiments of the present invention. , any modifications or equivalent replacements that do not deviate from the spirit and scope of the present invention are within the protection scope of the claims of the present invention pending application.

Claims (18)

1. A power optical network routing spectrum allocation method, characterized in that: When there is a power service connection allocation request in the power optical network, obtain the available spectrum index on each link in the power optical network; According to the available spectrum index on each link, different spectrum window positions are set under different modulation formats to determine the candidate solution sets of service requests that meet the corresponding distance requirements; From the candidate solution set, the modulation format and routing frequency spectrum allocation conforming to preset rules are selected. 2. The electric power optical network routing spectrum allocation method according to claim 1, characterized in that: the power service connection allocation request includes source nodes, destination nodes, service types and request for service connections in the electric power optical network rate information. 3. The electric power optical network routing spectrum allocation method as claimed in claim 1, characterized in that: before the available spectrum index on each link in the electric power optical network, it also includes: Sort business requests based on business priority and request rate. 4. The electric power optical network routing spectrum allocation method as claimed in claim 3, characterized in that: said service requests are sorted according to service priority and request rate, comprising: Real-time sensitive services have high priority, and non-real-time delay-sensitive services have low priority; Among the services in the same priority, the higher the request rate, the higher the ranking. 5. The electric power optical network routing spectrum allocation method as claimed in claim 1, characterized in that: according to the available spectrum index on each link, different spectrum window positions are set under different modulation formats to determine that the corresponding distance requirements are met Candidate solution sets for business requests, including: According to the rate of the service request, different modulation formats are sequentially selected from high order to low order, and the number of transmission frequency slots required by the service under the different modulation formats is calculated; Calculate the spectrum window set S according to the available spectrum index of the spectrum on each link and the number of service transmission frequency slots; Sequentially select the spectral window s in the spectral window set S, s∈S; Establish a virtual network topology, and use the k-shortest path algorithm in the virtual network topology to calculate the first k shortest paths between the source node and the destination node in the service request, and make the path length less than the transmission distance limit of the current order modulation format The path, its modulation format, and the spectral window s are stored in the candidate solution set of the service request until all the spectral windows in the spectral window set S are processed. 6. The electric power optical network routing spectrum allocation method as claimed in claim 5, wherein: the construction method of the spectral window set S comprises: For the service request that the number of required transmission frequency slots is n, S={[1,n],[2,n+1],...,[B-n+1,B]}; where, B is the fiber link The total number of spectrum resources on the road. 7. The electric power optical network routing spectrum allocation method according to claim 5, wherein: the candidate solution set includes: a modulation distance-limited path, a modulation format corresponding to the modulation distance-limited path, and a spectral window s gather. 8. The electric power optical network routing spectrum allocation method as claimed in claim 6, characterized in that: the calculation formula of the number of transmission frequency slots is: the transmission rate of a single frequency slot under the number of transmission frequency slots n=transmission rate/modulation format m . 9. The electric power optical network routing spectrum allocation method as claimed in claim 8, characterized in that: selecting a modulation format that meets preset rules from the candidate solution set includes: When the candidate solution set of the service is empty, set the next low-order modulation format, recalculate the number of transmission frequency slots required by the service under the set modulation format, and turn to the candidate solution of the service if the low-order modulation format is empty Set is not empty step. 10. The power optical network routing spectrum allocation method as claimed in claim 8, characterized in that: selecting the routing spectrum allocation that meets the preset rules from the candidate solution set includes: If the candidate solution set of the service is not empty, calculate the total number of link spectrums used by each path in the candidate solution set, select a path with the least number, and return the corresponding spectrum window of the path, and end the search for the best route for the service request ; Reserve communication spectrum resources for the spectrum window position on each fiber optic link of the path. 11. The power optical network routing spectrum allocation method according to claim 10, characterized in that: the total number of link spectrums=the number of optical fiber links*the number of required transmission frequency slots. 12. A power optical network routing spectrum distribution system, characterized in that: The obtaining module is used to obtain the available spectrum index on each link in the electric power optical network when there is a power service connection allocation request in the electric power optical network; A determining module, configured to set different spectral window positions under different modulation formats according to available spectrum indexes on each link to determine candidate solution sets of service requests that meet corresponding distance requirements; An allocation module, configured to select a modulation format conforming to preset rules and route spectrum allocation from the candidate solution set. 13. The electric power optical network routing spectrum allocation system according to claim 12, characterized in that: the power service connection allocation request includes source nodes, destination nodes, service types and request for service connections in the electric power optical network rate information. 14. The electric power optical network routing spectrum allocation system according to claim 12, characterized in that: it also includes a sorting module for prior Sort business requests by level and request rate. 15. The electric power optical network routing spectrum distribution system as claimed in claim 14, characterized in that: the sorting module includes: The prioritization unit is used for high priority for real-time sensitive services, and low priority for non-real-time delay-sensitive services; The request rate sorting unit is used for services in the same priority, the higher the request rate, the higher the sorting. 16. The electric power optical network routing spectrum distribution system as claimed in claim 12, characterized in that: the determination module includes: The first calculation unit is used to sequentially select different modulation formats from high order to low order according to the rate of the service request, and calculate the number of transmission frequency slots required by the service under the different modulation formats; The second calculation unit is used to calculate the spectrum window set S according to the available spectrum index of each link spectrum and the number of service transmission frequency slots; The selection unit is used to sequentially select the spectral window s in the spectral window set S, s∈S; The establishment unit is used to establish a virtual network topology, and uses the k-shortest path algorithm to calculate the first k shortest paths between the source node and the destination node in the virtual network topology, and the path length is less than the transmission distance limit of the current order modulation format The path, its modulation format, and the spectral window s are stored in the candidate solution set of the service request until all the spectral windows in the spectral window set S are processed. 17. The power optical network routing spectrum allocation system according to claim 16, characterized in that: the number of transmission frequency slots is expressed as: number of transmission frequency slots n=transmission rate/transmission rate of a single frequency slot under modulation format m. 18. The electric power optical network routing spectrum distribution system according to claim 12, characterized in that: the distribution module includes: The modulation format setting unit is used to set the next low-order modulation format when the candidate solution set of the service is empty, and recalculate the number of transmission frequency slots required by the service under the set modulation format. If the low-order modulation format has If it is empty, the candidate solution set for turning to the business is not an empty step; The routing allocation unit is used to calculate the total number of link spectrums used by each path in the candidate solution set when the service candidate solution set is not empty, select and return a path with the least number, and its corresponding modulation format and spectrum window, End the search for the best route for service requests.