A resource allocation method for an all-optical space division multiplexing elastic optical network

Abstract

The application relates to a resource allocation method of a full-optical space division multiplexing elastic optical network, and belongs to the technical field of optical network communication. The method comprises the steps of fiber core grouping and spectrum partitioning, fiber core selection and L-shaped frequency block allocation. The fiber core grouping and spectrum partitioning step divides a seven-core optical fiber into three groups, divides an in-group priority area, and sets a grouping partition weight coefficient. The fiber core selection step arranges the fiber cores in descending order according to the fiber core weight values according to the frequency slot usage, the link length and the number of overlapping frequency slots between the fiber cores on a path, selects the fiber core with the maximum weight value as a transmission fiber core, the L-shaped frequency block allocation step obtains an L-shaped frequency block set satisfying the connection type limitation and the crosstalk threshold limitation according to the remaining unallocated frequency blocks and the frequency block allocation limitation condition, and selects the L-shaped frequency block with the maximum weight value as a transmission frequency block by using an L-shaped frequency block weight calculation formula. The application can balance the number of idle slice machines at each node on the network and guarantee efficient transmission of service requests.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical network communication, and relates to a resource allocation method of a full-optical space division multiplexing elastic optical network. BACKGROUND

[0002] In recent years, with the rapid development of new generation information technologies represented by big data, edge computing and video on demand, the data traffic in the current network is growing exponentially. In order to meet the transmission demand of network traffic, an elastic optical network (EON) based on orthogonal frequency division multiplexing technology is developed, which dynamically allocates bandwidth according to the capacity of each incoming request, and then realizes efficient utilization of spectrum resources.

[0003] In the EON, there are three constraint conditions for spectrum resource allocation: spectrum contiguity, spectrum consistency and spectrum non-overlapping. The spectrum contiguity requires that the relative position of the frequency slot occupied by the optical signal from the source node to the destination node in the spectrum must be continuous; the spectrum consistency requires that all continuous frequency slots allocated to the service request must remain the same in each link in the entire optical path of the request; and the spectrum non-overlapping restriction requires that each service bandwidth request cannot have spectrum overlapping. With the exponential growth of network data traffic, the EON using single core / single mode has been unable to meet the increasing bandwidth demand. The space division multiplexing (SDM) technology using multi-core fiber (MCF) expands the capacity of the fiber from the physical structure, which makes the transmission capacity of the fiber increase exponentially.

[0004] Therefore, the space division multiplexing elastic optical network (SDM-EONs) combining the SDM technology with the EON has the advantages of flexible spectrum allocation mode, large transmission capacity and high resource utilization rate, and can alleviate the problem of insufficient bandwidth for large bandwidth data transmission, but it also has the problem of inter-core crosstalk (ICXT). With the establishment and release of services, many small and discontinuous idle frequency slot blocks will be generated on the spectrum of the network link. The above restrictions make the routing, spectrum and core assignment (RSCA) problem in the SDM-EONs very challenging, and if any of the above constraint conditions is not met, it will lead to service request blocking.

[0005] The allocation of fragmented bandwidth is essential to ensure efficient use of valuable spectrum resources in SDM-EONs, and the slicing-stitching technology can allocate requests to discontinuous frequency slots, making full use of spectrum fragmentation in the network. However, due to the physical nature of the slicing process, head connection type (Head Connect Type) and tail connection (Tail Connect Type) type restrictions will be introduced at intermediate nodes, where the service is sliced once, and regardless of whether the slicing results in a head connection type or a tail connection type, the occupied frequency slots appear as an L-shaped frequency block and an offset rectangular frequency block on the link frequency slot map. In SDM-EONs, due to the irregularity of the L-shaped frequency block, and the scattered distribution of frequency slots occupied by different service requests in the fiber core, the inter-core crosstalk suffered by each frequency slot is different. Therefore, during the slicing process, the distribution state of the available frequency slots on the link needs to be considered, and the head connection and tail connection problems caused by the physical limitations of the slicing machine, as well as the inter-core crosstalk problem.

[0006] In summary, it is of great significance to propose a new and practical resource allocation method for the current problems of SDM-EONs. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a resource allocation method for an all-optical space division multiplexing elastic optical network, which takes reducing the request blocking rate as the primary optimization goal, while trying to avoid the overuse of slicing machines as much as possible, and taking into account network performance and cost.

[0008] To achieve the above purpose, the present application provides the following technical solutions:

[0009] A resource allocation method for an all-optical space division multiplexing elastic optical network, comprising the following steps:

[0010] S1, numbering and grouping the fiber cores in the optical fiber, specifically: grouping the cores numbered 1, 3 and 5 into a group, denoted as group 1; grouping the cores numbered 2, 4 and 6 into a group, denoted as group 2; the core numbered 7 is a separate group, denoted as group 3;

[0011] Divide all the frequency slot resources of each group of cores into regions S1 and S2, and set the S1 region of group 1 as the highest priority partition of group 1, and set the S2 region of group 2 as the highest priority partition of group 2; the priority of S1 region and S2 region in group 3 is the same;

[0012] S2, calculate the number of frequency slots FS required by the service request under BPSK modulation format r ;

[0013] S3. Search for the K shortest paths between the source node and the destination node, and add them to the candidate path set; sort the paths in ascending order of length, and denote the k-th path as P. k and initialize k = 1;

[0014] S4. Calculate the weight value of each fiber core in group 1 and group 2 and add it to the candidate fiber core set. Sort the fiber cores in the candidate path in ascending order according to the weight value of the fiber core and select the fiber core with the largest weight value as the transmission fiber core.

[0015] S5. Determine the remaining unallocated frequency blocks UR S,D,R Initialization allocation constraints Add it to the frequency block allocation constraint set ARL S,D,R ;

[0016] S6. Select the remaining unallocated frequency blocks UR S,D,R The rectangular frequency block with the smallest starting node and the smallest unassigned sequence number. and allocate constraints from the frequency block set ARL S,D,R From Corresponding allocation restrictions Search for available L-shaped frequency blocks within the available frequency slot range and save them to the L-shaped frequency block set. middle;

[0017] Where u represents the sequence number of the unallocated frequency block, x represents the source node or intermediate node on the k-th path, d represents the destination node of the service request, and r represents the rectangular frequency block. The number of consecutive frequency slots at the bottom;

[0018] S7, Retained Set After L-shaped frequency blocks that meet the crosstalk threshold limit or the connection type are included, if the set If not empty, then the set is selected using the L-type frequency block determination formula. The i-th L-type frequency block As a transmission frequency block, proceed to step S8; if the set If empty, the current transmission fiber core is removed from the candidate fiber core set, and the process proceeds to step S9;

[0019] S8, L-shaped frequency block Add to the alternative L-shaped frequency block set AL S,D,R Update the remaining unallocated frequency blocks and their allocation restrictions. If the remaining unallocated frequency blocks are 0, the service transmission is successful. Output the optical path selected by the service, the fiber core number, the set of alternative L-shaped frequency blocks, and the number of slicers used at each node. If the remaining unallocated frequency blocks are not 0, return to step S6.

[0020] S9, if there is a usable core in the alternative core set, select the core with the largest weight value in the usable core as the transmission core, and return to step S5; if there is no usable core in the alternative core set, the transmission path k=k+1, if k≤K, return to step S4, if k>K, the current service transmission fails, and the service request is blocked.

[0021] Further, in step S4, the core weight value calculation method is:

[0022]

[0023]

[0024]

[0025] In the formula, indicates the weight value of the candidate path P k upper core c j , l i indicates the i-th link on the candidate path P k , γ(c j ) indicates the serial number of the group to which the current core c j belongs, s k indicates the frequency spectrum partition number, indicates the frequency spectrum partition s k contains, indicates the group partition coefficient of the spectrum partition s in the core group k AD(c j ) indicates the adjacent core set of the core c j , |AD(c j )| indicates the number of adjacent cores of the core c j , indicates the state of the y-th frequency slot of the core c i on the link l j , indicates the state of the y-th frequency slot of the adjacent core c', indicates the interference degree of the frequency slot to the adjacent core frequency slot .

[0026] Further, in step S5, the remaining unallocated frequency block UR S,D,R is represented as:

[0027]

[0028] In the formula, s indicates the source node of the service request;

[0029] The allocation restriction condition is represented as:

[0030]

[0031] Furthermore, if the frequency block selected in step S6 satisfy:

[0032] x=s, and u=1

[0033] In the formula, s represents the source node of the service request; then the L-shaped frequency block and the L-shaped frequency block set... It is expressed as follows:

[0034]

[0035]

[0036] In the formula, The number of L-type frequency blocks in the L-type frequency block set is represented by l. x Indicates L-shaped frequency block The first node number, l b Indicates L-shaped frequency block The smallest occupied frequency slot number, l m Indicates L-shaped frequency block The largest occupied frequency slot number, l p Indicates L-shaped frequency block The convex node number, l t Indicates L-shaped frequency block The convex frequency slot number, l s Indicates L-shaped frequency block direction, l d Indicates the sequence number of the destination node d;

[0037] Meanwhile, in step S7, the set is retained. The L-shaped frequency blocks that satisfy the crosstalk threshold limit. The crosstalk threshold limit is expressed as follows:

[0038]

[0039] In the formula, [l b ,l m ] indicates an L-shaped frequency block The frequency slot number range it occupies Indicates L-shaped frequency block Crosstalk threshold, XT th Indicates the maximum crosstalk threshold;

[0040] The formula for determining the L-type frequency block is as follows:

[0041]

[0042] In the formula, s represents a partition group weight coefficient, s h(f) t(f) represents a partition to which a frequency slot f belongs, and t(f) represents a number of links occupied by the frequency slot f;

[0043] After the transmission frequency block is determined, the crosstalk suffered by the frequency slot interval [l b ,l m ] is recorded, and all the frequency slots in the interval [l b ,l m ] are reserved to the original frequency slot set OF S,D,R ;

[0044] And, for updating the remaining unallocated frequency block in step S8, the following formula is used:

[0045]

[0046] In the formula, s represents the source node of the service request; r represents the number of bottom frequency slots of the L-shaped frequency block , and r' represents the number of convex frequency slots of the L-shaped frequency block ;

[0047] The updating of the allocation limit condition of the remaining unallocated frequency block uses the following formula:

[0048]

[0049]

[0050] Further, in step S6, if the selected frequency block does not satisfy:

[0051] x = s, and u = 1

[0052] In the formula, s represents the source node of the service request;

[0053] then the available frequency slot interval FAR is obtained according to RL, l v and l s , and the idle L-shaped frequency block is searched in the interval FAR and saved in the L-shaped frequency block set ; wherein, RL represents the reference frequency block, l v represents the node sequence number of the reference frequency block RL; l s represents a Boolean variable, which is used to represent that the selected transmission frequency block should be on the left side or the right side of the frequency block RL, corresponding to the value of 0 or 1 respectively;

[0054] The available frequency slot interval FAR is specifically:

[0055]

[0056] In the formula, RL(l b) represents the lowest frequency slot number of the reference frequency block RL, RL(l x ) represents the start node number of the reference frequency block RL, RL(l m ) represents the maximum frequency slot number of the reference frequency block RL, RL(l p ) represents the convex node number of the reference frequency block RL, RL(l t ) represents the convex frequency slot number of the reference frequency block RL, fs end represents the maximum available frequency slot number of the maximum fiber link;

[0057] Meanwhile, the L-type frequency block satisfying the connection type is reserved in step S7. The connection type includes a head connection type and a tail connection type, and the L-type frequency block is determined by the relative position of the frequency slot number interval [l b , l m ] occupied by the L-type frequency block and the original frequency slot interval of the L-type frequency block; the L-type frequency block satisfying the head connection type or the tail connection type in the L-type frequency block set is reserved, and the connection type satisfied by the L-type frequency block is recorded;

[0058] The crosstalk threshold limit required by the head connection type is:

[0059]

[0060] In the formula, XT represents the crosstalk threshold of the L-type frequency block th XT represents the maximum crosstalk threshold;

[0061] The crosstalk threshold limit required by the tail connection type is:

[0062]

[0063] Meanwhile, for the update of the allocation limit condition of the unallocated frequency block in step S8, when the L-type frequency block satisfies the head connection type, the update mode of the allocation limit condition of the unallocated frequency block is as follows:

[0064]

[0065]

[0066] In the formula, r' represents the convex frequency slot number of the L-type frequency block l x represents the first node number of the L-type frequency block l p represents the convex node number of the L-type frequency block l t represents the convex node number of the L-type frequency block The convexity frequency gap sequence number, l b The L-shaped frequency block is represented The minimum frequency gap sequence number, l m The L-shaped frequency block is represented The maximum frequency gap sequence number occupied

[0067] When the L-shaped frequency block satisfies the tail connection type, the updating mode of the allocation limit condition of the unallocated frequency block is as follows:

[0068]

[0069]

[0070] In the formula, The L-shaped frequency block is represented The bottom frequency gap number of the L-shaped frequency block.

[0071] The present application has the beneficial effects that the present application can reduce the use of slicers as much as possible, balance the number of idle slicers at each node on the network, and ensure efficient transmission of service requests, thereby effectively reducing the blocking rate of service requests.

[0072] Other advantages, objects, and features of the present application will be apparent to those skilled in the art from the following specification, and will be learned from practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the following specification. BRIEF DESCRIPTION OF DRAWINGS

[0073] In order to make the purposes, technical solutions and advantages of the present application clearer, the preferred detailed description of the present application will be combined with the drawings as follows, wherein:

[0074] Figure 1 The resource allocation method flowchart of the present application;

[0075] Figure 2 The core distribution diagram of a seven-core optical fiber;

[0076] Figure 3 The description diagram of two slice types generated by the L-shaped slice and the L-shaped frequency block. DETAILED DESCRIPTION

[0077] The present application is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar, but not necessarily identical, elements. The embodiments shown are clearly exemplary and the features shown in the various consistently can be combined with each other, where possible, without departing from the scope of the present application.

[0078] The accompanying drawings, which are included to provide a further understanding only, illustrate embodiments of the application and together with the description serve to explain the principle of the application. In the drawings:

[0079] Corresponding identical or similar components in the drawings of the embodiments of the present application have the same or similar reference numerals; in the description of the present application, it should be understood that the orientation or position relationship indicated by terms such as "upper", "lower", "left", "right", "front", "back" and the like are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the position relationship in the drawings are only for illustrative purposes, and cannot be understood as a limitation of the present application, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0080] As shown in Figure 1 , a resource allocation method for an all-optical space division multiplexing elastic optical network, the steps are as follows:

[0081] S1, according to the principle of vertex coloring in graph theory, the non-adjacent cores are divided into a group, according to the core grouping strategy, the cores of seven-core fiber can be divided into three groups, and at the same time, combining the pre-defined spectrum block, all the frequency slot resources in the core on the link are divided to form a priority spectrum area. The specific operation is as follows:

[0082] The cores in the optical fiber are numbered and grouped, the cores numbered 1, 3 and 5 are divided into a group, marked as group 1; the cores numbered 2, 4 and 6 are divided into a group, marked as group 2; the core numbered 7 is separately as a group, marked as group 3, as shown in Figure 2 ;

[0083] All frequency slot resources of each group of cores are divided into regions S1 and S2, and the S1 region of group 1 is set as the highest priority partition of group 1, and the S2 region of group 2 is set as the highest priority partition of group 2; the S1 region and the S2 region in group 3 have the same priority;

[0084] Different group partitions are given weight coefficients In order to improve the use rate of high-priority region fragmented frequency slots.

[0085] S2, service request R N After (s, d, B) arrives, the number of frequency slots required under the BPSK modulation format is calculated Recorded as FS r ; Wherein N is the service request serial number, s and d are the source node and destination node of the service request respectively, B is the service request rate, each optical fiber link has |F| unit frequency slots (FS), FS = 12.5GHz.

[0086] S3, search K shortest paths between the source node and the destination node, and add the candidate path set; sort the paths in ascending order of length, and record the kth path as P k , and initialize k = 1.

[0087] S4, calculate the weight value of each core in group 1 and group 2 and add it to the candidate core set, sort the cores in the candidate path in ascending order according to the core weight value, and preferentially select the core with the largest weight value as the transmission core.

[0088] If there is no frequency block that meets the service transmission in all cores of group 1 and group 2, select core 7 in group 3 as the service transmission core, search for available frequency block resources, and transmit the service request.

[0089] Wherein, the core weight value calculation method is:

[0090]

[0091]

[0092]

[0093] In the formula, Indicates the weight value of the candidate path P k on the core c j , l i Indicates the i-th link on the candidate path P k , γ(c j ) indicates the serial number of the group to which the current core c j belongs, s k Indicates the frequency spectrum partition number, Indicates the frequency spectrum partition sk a set of included frequency slots, denotes a fiber core group a spectrum partition s of the middle frequency k a group partition coefficient of the middle frequency, AD(c j ) denotes a set of adjacent fiber cores of fiber core c j |AD(c j )| denotes the number of adjacent fiber cores of fiber core c j denotes a link l i fiber core c j a state of the yth frequency slot (if 0, it indicates that the frequency slot y has been occupied; if 1, it indicates that the frequency slot y is idle), denotes a state of the yth frequency slot of the adjacent fiber core c', denotes a frequency slot an interference degree of the frequency slot of the adjacent fiber core .

[0094] S5, determining a remaining unallocated frequency block UR S,D,R ; initializing an allocation restriction condition and adding it to a set of frequency block allocation restriction conditions ARL S,D,R .

[0095] The remaining unallocated frequency block UR S,D,R is represented as:

[0096]

[0097] In the formula, s represents a source node of a service request;

[0098] The allocation restriction condition is represented as:

[0099]

[0100] S6, selecting a rectangular frequency block with the smallest starting node and the smallest unallocated serial number in the remaining unallocated frequency block UR S,D,R and obtaining a corresponding allocation restriction condition from the set of frequency block allocation restriction conditions ARL S,D,R . searching for an idle L-shaped frequency block in the available frequency slot interval and saving it to a set of L-shaped frequency blocks . The L-shaped frequency block is shown in Figure 3 . In the formula, u represents the serial number of the unallocated frequency block, x represents a source node or an intermediate node on the kth path, d represents a destination node of the service request, and r represents the number of consecutive frequency slots at the bottom of the rectangular frequency block .

[0101] According to the conditions satisfied by the selected frequency block, the following cases are divided:​​

[0102] 1) If the selected frequency block satisfies x = s and u = 1, then the L-shaped frequency block and the L-shaped frequency block set are represented as follows:

[0103]

[0104]

[0105] wherein, denotes the number of L-shaped frequency blocks in the L-shaped frequency block set, l x denotes the first node number of the L-shaped frequency block , l b denotes the minimum frequency slot number occupied by the L-shaped frequency block , l m denotes the maximum frequency slot number occupied by the L-shaped frequency block , l p denotes the convex node number of the L-shaped frequency block , l t denotes the convex frequency slot number of the L-shaped frequency block , l s denotes the direction of the L-shaped frequency block , l d denotes the number of the destination node d. The L-shaped frequency block representation method is also used for rectangular frequency blocks, and the default settings are: l p = l d , l t = l m + 1, l s = 0.

[0106] The corresponding available frequency slot interval FAR is [0, fs end ], and the idle L-shaped frequency block is searched in the interval and saved in the L-shaped frequency block set .

[0107] 2) If the selected frequency block does not satisfy x = s and u = 1, then the available frequency slot interval FAR is obtained according to RL, l v and l s , and the idle L-shaped frequency block is searched in the interval and saved in the L-shaped frequency block set ; wherein, RL denotes the reference frequency block, l v denotes the node number of the reference frequency block RL; l s denotes a Boolean variable, which is used to indicate whether the selected transmission frequency block should be on the left or right side of the frequency block RL, corresponding to the values of 0 or 1, respectively;

[0108] According to l v And l s The search of the frequency slot interval FAR of the available L-shaped frequency block is divided into the following four cases according to the different values:

[0109]

[0110] In the formula, RL (l b ) represents the lowest frequency slot sequence number of the reference frequency block RL, RL (l x ) represents the starting node sequence number of the reference frequency block RL, RL (l m ) represents the maximum frequency slot sequence number of the reference frequency block RL, RL (l p ) represents the convex node sequence number of the reference frequency block RL, RL (l t ) represents the convex frequency slot sequence number of the reference frequency block RL, fs end represents the maximum available frequency slot sequence number of the maximum optical fiber link.

[0111] S7, the reserved set After the L-shaped frequency block satisfying the crosstalk threshold limit or satisfying the connection type in the set is not empty, the L-shaped frequency block in the set is selected through the L-shaped frequency block determination formula as the transmission frequency block, and step S8 is entered; if the set is empty, the current transmission fiber core is deleted from the candidate fiber core set, and step S9 is entered.

[0112] Specifically:

[0113] 1) According to case 1) in step S6, the L-shaped frequency block satisfying the crosstalk threshold limit in the set is reserved. The L-shaped frequency block determination formula is specifically:

[0114]

[0115] In the formula, s represents the partition grouping weight coefficient, s h ( f ) represents the partition to which the frequency slot f belongs, and t(f) represents the number of links occupied by the frequency slot f.

[0116] The crosstalk threshold limit is represented as:

[0117]

[0118] In the formula, [l b ,l m ] represents the frequency slot sequence number interval occupied by the L-shaped frequency block , XT represents the crosstalk threshold of the L-shaped frequency block .th This represents the maximum crosstalk threshold.

[0119] Furthermore, if set If not empty, after selecting the transmission frequency block, record the frequency slot interval [l]. b ,l m The crosstalk received, and the interval [l] is preserved. b ,l m All frequency slots within ] to the original frequency slot set OF S,D,R .

[0120] 2) Based on situation 2) in step S6, in the set The L-shaped frequency blocks that meet the connection type are reserved. Based on the L-shaped frequency blocks... Occupied frequency slots [l b ,l m [and the original frequency gap range of the L-shaped frequency block] Depending on their relative positions, there are two types: head-connection type and tail-connection type. This yields the original frequency slot range. The cumulative crosstalk value of each frequency slot is calculated, and the L-type frequency block is calculated separately. Does it meet the crosstalk threshold conditions for both head-connection and tail-connection types, and retain the L-shaped frequency block set? The L-shaped frequency blocks that satisfy the head connection or tail connection type are recorded.

[0121] The crosstalk threshold that the header connection type needs to meet is:

[0122]

[0123] In the formula, Indicates L-shaped frequency block Crosstalk threshold, XT th Indicates the maximum crosstalk threshold;

[0124] The crosstalk threshold that tail-connection types need to meet is:

[0125]

[0126] S8, L-shaped frequency block Add to the alternative L-shaped frequency block set AL S,D,R Update the remaining unallocated frequency blocks and their allocation restrictions. If the remaining unallocated frequency blocks are 0, the service transmission is successful. Output the optical path selected by the service, the fiber core number, the set of alternative L-shaped frequency blocks, and the number of slicers used at each node. If the remaining unallocated frequency blocks are not 0, return to step S6.

[0127] Specifically:

[0128] 1) Based on situation 1) in step S7, the L-shaped frequency block... Add to the alternative L-shaped frequency block set AL S,D,R ,like Unallocated frequency blocks Corresponding allocation restrictions Add to the frequency block allocation constraint set ARL S,D,R If l t ≠l d Update u = u + 1, and remove the unallocated frequency blocks. Corresponding allocation restrictions Add to the frequency block allocation constraint set ARL S,D,R .

[0129] Update the allocation constraints for unallocated frequency blocks:

[0130]

[0131]

[0132] Update remaining unallocated frequency blocks:

[0133]

[0134] In the formula, Indicates L-shaped frequency block The number of bottom frequency slots, r′ represents the L-shaped frequency block. The number of raised frequency slots; the calculation rules for the remaining unallocated frequency blocks are as follows:

[0135]

[0136]

[0137] 2) Based on step S7, case 2), select the L-type frequency block using the L-type frequency block determination formula. As a transmission frequency block, and determining its connection type, the L-shaped frequency block... Add to the alternative L-shaped frequency block set AL S,D,R When the L-type frequency block meets the header connection type, if Unallocated frequency blocks Corresponding allocation restrictions Add to the frequency block allocation constraint set ARL S,D,R If l t ≠l d Update u = u + 1, and remove the unallocated frequency blocks. Corresponding allocation restrictions Add to the frequency block allocation constraint set ARL S,D,R When the L-type frequency block meets the tail connection type, the same steps are performed.

[0138] When an L-type frequency block meets the header connection type, the update method for the allocation constraints of unallocated frequency blocks is as follows:

[0139]

[0140]

[0141] When an L-type frequency block meets the tail-connection type, the update method for the allocation constraints of unallocated frequency blocks is as follows:

[0142]

[0143]

[0144] Simultaneously, based on the connection type of the L-shaped frequency block, the crosstalk received by each frequency slot is updated:

[0145] When the L-shaped frequency block is a header-connected type, update the crosstalk received by each frequency slot:

[0146]

[0147] When the L-shaped frequency block is tail-connected, update the crosstalk received by each frequency slot:

[0148]

[0149] S9. If there is an available fiber core in the candidate fiber core set, select the fiber core with the largest weight value among the available fiber cores as the transmission fiber core and return to step S5; if there is no available fiber core in the candidate fiber core set, then the transmission path k = k + 1. If k ≤ K, then return to step S4. If k > K, then the current service transmission fails and the service request is blocked.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A resource allocation method for an all-optical space-division multiplexing elastic optical network, characterized in that: The method includes the following steps: S1. Number and group the fiber cores in the optical fiber, specifically: group the fiber cores numbered 1, 3 and 5 into one group, called group 1; group the fiber cores numbered 2, 4 and 6 into one group, called group 2; and group the fiber core numbered 7 into a separate group, called group 3. All frequency slot resources of each group of fiber cores are divided into regions S1 and S2. At the same time, region S1 of group 1 is set as the highest priority partition of group 1, and region S2 of group 2 is set as the highest priority partition of group 2; region S1 and region S2 in group 3 have the same priority. S2. Calculate the number of frequency slots required in the BPSK modulation format based on the service request. ; S3, Searching between the source node and the destination node K Find the shortest path and add it to the candidate path set; sort the paths in ascending order of length, and then... k The path is denoted as and initialize ; S4. Calculate the weight value of each fiber core in Group 1 and Group 2 and add it to the candidate fiber core set. Sort the fiber cores in the candidate path in ascending order according to their weight values, and select the fiber core with the largest weight value as the transmission fiber core. The fiber core weight value is calculated as follows: In the formula, Indicate candidate path upper fiber core The weight value, Indicate candidate path Upper Link, Indicates the current fiber core The group number to which it belongs. Indicates the spectrum partition number. Indicates spectrum partition The set of included frequency slots Indicates fiber core grouping Mid-spectrum partitioning Grouping partition coefficient, Indicates fiber core Adjacent fiber core sets, Indicates fiber core The number of adjacent fiber cores. Indicates link fiber core Upper The state of each frequency band, Indicates adjacent fiber cores The The state of each frequency band, Indicates frequency slot For adjacent fiber core frequency gaps The degree of interference; S5. Determine the remaining unallocated frequency blocks. Initialization allocation constraints And add it to the set of frequency block allocation constraints. ; S6. Select the remaining unallocated frequency blocks. The rectangular frequency block with the smallest starting node and the smallest unassigned sequence number. and from the set of frequency block allocation constraints From Corresponding allocation restrictions Search for available L-shaped frequency blocks within the available frequency slot range and save them to the L-shaped frequency block set. In; among them, u Indicates the sequence number of the unallocated frequency block. x Indicates the first k The source node or intermediate node on the path, d Indicates the destination node of the business request. r Represents rectangular frequency blocks The number of consecutive frequency slots at the bottom; S7, Retained Set After L-shaped frequency blocks that meet the crosstalk threshold limit or the connection type are included, if the set If not empty, then the set is selected using the L-type frequency block determination formula. The Middle i L-shaped frequency block As a transmission frequency block, proceed to step S8; if the set If empty, the current transmission fiber core is removed from the candidate fiber core set, and the process proceeds to step S9; S8, L-shaped frequency block Add to the alternative L-shaped frequency block set Update the remaining unallocated frequency blocks and their allocation restrictions. If the remaining unallocated frequency blocks are 0, the service transmission is successful. Output the optical path selected by the service, the fiber core number, the set of alternative L-shaped frequency blocks, and the number of slicers used at each node. If the remaining unallocated frequency blocks are not 0, return to step S6. S9. If there are available fiber cores in the candidate fiber core set, select the fiber core with the largest weight value among the available fiber cores as the transmission fiber core, and return to step S5; if there are no available fiber cores in the candidate fiber core set, then the transmission path... ,like Then return to step S4, if If this fails, the service transmission will fail, and the service request will be blocked.

2. The resource allocation method according to claim 1, characterized in that: In step S5, the remaining unallocated frequency blocks Represented as: In the formula, s Indicates the source node of the business request; The allocation constraints are expressed as follows: 。 3. The resource allocation method according to claim 1, characterized in that: If the frequency block selected in step S6 satisfy: In the formula, s This represents the source node of the service request; then, the L-shaped frequency block and the set of L-shaped frequency blocks... It is expressed as follows: In the formula, This indicates the number of L-type frequency blocks in the L-type frequency block set. Indicates L-shaped frequency block The first node number, Indicates L-shaped frequency block The smallest occupied frequency slot number, Indicates L-shaped frequency block The largest occupied frequency slot number, Indicates L-shaped frequency block The convex node number, Indicates L-shaped frequency block The convex frequency slot number, Indicates L-shaped frequency block direction, Indicates the destination node The serial number; Meanwhile, in step S7, the set is retained. L-shaped frequency blocks that meet the crosstalk threshold limit.

4. The resource allocation method according to claim 3, characterized in that: In step S7, the crosstalk threshold limit is expressed as follows: In the formula, Indicates L-shaped frequency block The frequency slot number range it occupies Indicates L-shaped frequency block The crosstalk threshold, Indicates the maximum crosstalk threshold; The formula for determining the L-type frequency block is as follows: In the formula, Indicates the partition grouping weight coefficient. Indicates frequency slot f The partition to which it belongs Indicates frequency slot f The number of links occupied; After determining the transmission frequency block, record the frequency slot interval. The crosstalk received, and the interval is preserved. All frequency slots within the original frequency slot set ; Furthermore, in step S8, the update of the remaining unallocated frequency blocks is as follows: In the formula, Indicates L-shaped frequency block The number of bottom frequency slots, Indicates L-shaped frequency block The number of convex frequency slots; The allocation constraints for the remaining unallocated frequency blocks are updated as shown in the following equation: 。 5. The resource allocation method according to claim 1, characterized in that: In step S6, if the selected frequency block Not satisfied: In the formula, s Indicates the source node of the business request; then according to RL , and The three items yielded the usable frequency gap range. and in the interval Search for available L-shaped frequency blocks and save them to the L-shaped frequency block set. In; among them, RL Indicates the reference frequency block. Indicates reference frequency block RL The node number, Represents a Boolean variable; The available frequency band Specifically: In the formula, Indicates reference frequency block RL The lowest frequency band number, Indicates reference frequency block RL The starting node number, Indicates reference frequency block RL Maximum frequency band number, Indicates reference frequency block RL The convex node number, Indicates reference frequency block RL The convex frequency slot number, Indicates the maximum available frequency slot number of the largest fiber optic link; Meanwhile, in step S7, L-type frequency blocks that meet the connection type are retained.

6. The resource allocation method according to claim 5, characterized in that: In step S7, the connection type includes head connection type and tail connection type, L-shaped frequency block The connection type is determined by the frequency slot number range it occupies. and its original frequency gap range The relative positions are determined; the L-shaped frequency block set is retained. The L-shaped frequency blocks that satisfy the head connection or tail connection type are recorded; The crosstalk threshold that the header connection type needs to meet is as follows: In the formula, Indicates L-shaped frequency block The crosstalk threshold, Indicates the maximum crosstalk threshold; The crosstalk threshold that tail-connection types need to meet is: 。 7. The resource allocation method according to claim 6, characterized in that: In step S8, when the L-type frequency block meets the header connection type, the update method for the allocation constraints of the unallocated frequency block is as follows: In the formula, Indicates L-shaped frequency block The number of convex frequency slots, Indicates L-shaped frequency block The first node number, Indicates L-shaped frequency block The convex node number, Indicates L-shaped frequency block The convex frequency slot number, Indicates L-shaped frequency block The smallest occupied frequency slot number, Indicates L-shaped frequency block The largest occupied frequency slot number; When an L-type frequency block meets the tail-connection type, the update method for the allocation constraints of unallocated frequency blocks is as follows: In the formula, Indicates L-shaped frequency block The number of bottom frequency slots.

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