A protection resource allocation method for space-division multiplexing optical network based on preset circle

Abstract

The present invention discloses a method for allocating protection resources for a space-division multiplexing optical network based on preset circles. Based on the total service bandwidth of links in the space-division multiplexing optical network, available idle protection resources, and optical network topology, the present invention generates a candidate preset circle set and determines the protection resources provided by the candidate preset circles. The candidate preset circles generated by this selection method are relatively small in number, high in quality, and low in algorithm complexity. Furthermore, all target preset circles are selected from the candidate preset circle set in combination with the total service bandwidth of each selected link, ultimately obtaining a target preset circle set. The target preset circle set can not only protect links on the circle, but also protect cross-links, and can also provide protection for other links with smaller total service bandwidths. In other words, the target preset circle set can efficiently allocate protection resources for the space-division multiplexing optical network, with high protection resource utilization, meeting the protection requirements of all service requests, and achieving high protection efficiency.

Description

Technical Field

[0001] The present invention specifically relates to a method for allocating protection resources in a space-division multiplexing optical network based on a preset circle. Background Art

[0002] Space-division multiplexing (SDM) technology refers to a method of achieving multiplexing by dividing space. Specifically, it combines multiple optical fibers into bundles to achieve SDM, or achieves SDM within the same optical fiber, so that the same frequency band can be reused in different spaces, thereby increasing the capacity of optical fiber transmission systems by an order of magnitude. Multi-core fiber technology, as one of the channel processing methods to achieve SDM, enables multiple signals to be transmitted independently along different fiber cores. However, network failures can sometimes lead to large amounts of data loss, causing significant losses to network operators. Therefore, it is necessary to protect the network's transmission paths.

[0003] However, traditional protection solutions cannot meet the protection requirements of all service requests, use a large number of idle protection resources, and cannot efficiently allocate protection resources for space-division multiplexing optical networks.

[0004] Therefore, it is necessary to invent a method for allocating protection resources in a space-division multiplexing optical network based on a preset circle to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for allocating protection resources in a space-division multiplexing optical network based on preset circles. The target preset circle set Z obtained by the present invention is * It can not only protect the link on the circle, but also protect the cross-link, and at the same time provide protection for other links with smaller total bandwidth, that is, the target preset circle set Z * The invention can efficiently allocate protection resources to the space-division multiplexing optical network, with high utilization rate of protection resources, can meet the protection requirements of all business requests, and has high protection efficiency, so as to solve the above-mentioned deficiencies in the technology.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a method for allocating protection resources in a space-division multiplexing optical network based on a preset circle, comprising the following steps:

[0007] Step 1: Obtain the total service bandwidth of service requests in all fiber cores on each link in the space-division multiplexing optical network;

[0008] Step 2: Set y e It is the idle protection resource available on each link in the space-division multiplexing optical network;

[0009] Step 3: Based on the total service bandwidth of the link, available idle protection resources, and the optical network topology, a candidate preset circle set is generated and the protection resources provided by the candidate preset circle set are determined;

[0010] Step 4: Determine the target preset circle based on the total service bandwidth according to the protection resources provided by the candidate preset circle set.

[0011] In the aforementioned method for allocating protection resources in a space-division multiplexing optical network based on a preset circle, in step 1, the total service bandwidth of service requests in all fiber cores on each link in the space-division multiplexing optical network is obtained. The specific steps are as follows:

[0012] 1.1. Let G(V,E,C) be a space-division multiplexing optical network, and R be the set of all service requests in G;

[0013] Where V is the set of nodes in the network topology;

[0014] E is a set of directed links;

[0015] C is the core collection;

[0016] 1.2, set is the bandwidth of r in the cth fiber core on link e;

[0017] Among them, e∈E, is the e-th link in G,

[0018] c∈C, is the c-th fiber core in G;

[0019] 1.3. The formula for calculating the total service bandwidth of service requests in all fiber cores on each link is as follows:

[0020]

[0021] Among them, r∈R is the rth service request in G.

[0022] In the aforementioned method for allocating protection resources in a space-division multiplexing optical network based on a preset circle, in step 2,

[0023] Among them, the idle protection resource set of each link in the space-division multiplexing optical network is F,

[0024] And f∈F, is the fth spectrum resource on each link,

[0025] |F| is the maximum idle protection resource on each link;

[0026] Among them, the available idle protection resources y on each link e Less than the maximum space on each link

[0027] Idle protection resource |F|, that is:

[0028] y e ≤|F|.

[0029] In the aforementioned method for allocating protection resources in a spatial division multiplexing optical network based on pre-configured circles, in step 3, a candidate pre-configured circle set is generated based on the total service bandwidth of the link, the available idle protection resources, and the optical network topology, and the protection resources provided by the candidate pre-configured circles are determined. The specific steps are as follows:

[0030] 3.1. Arrange all links in the space-division multiplexing optical network in descending order according to their total service bandwidth;

[0031] 3.2. Within a link, select any node v at both ends of the link in descending order and perform a depth-first search to obtain all possible set circles Q with both starting and ending points v and a path length greater than 3. Then sort the set circles Q in ascending order according to their path lengths.

[0032] Among them, v∈V is a node in the network topology;

[0033] 3.3. Select the single circle q in ascending order. If the idle protection resources of the single circle q can provide protection for the link, select it as the candidate pre-set circle;

[0034] Among them, q∈Q is a circle in the set circle Q;

[0035] 3.4. Repeat steps 3.2-3.3 for the remaining links, and organize the selected candidate preset circles to generate a candidate preset circle set Z;

[0036] 3.5. Based on the candidate preset circle set Z, determine the protection resources provided by it.

[0037] In the aforementioned method for allocating protection resources in a spatial division multiplexing optical network based on preset circles, in step 3.5, the protection resources provided by the candidate preset circle set Z are determined, specifically:

[0038] When the candidate preset circle set Z is determined, the protection resources it provides are all circle links and all cross links;

[0039] The services that can be protected by the candidate preset circle set Z include: all circle uplinks constituting the candidate preset circle set Z and cross-links formed by all nodes of the candidate preset circle set Z.

[0040] In the aforementioned method for allocating protection resources in a spatial division multiplexing optical network based on preset circles, in step 4, the target preset circle is determined based on the total service bandwidth according to the protection resources provided by the candidate preset circle set. The specific steps are as follows:

[0041] 4.1. Total bandwidth of services on all links x e Sort in descending order and select each link in turn according to the sorting;

[0042] 4.2. Let the target preset circle set be Z*. If Z* is not empty, then select the service total bandwidth x of the selected link in Z*. e Provide protection for the target preset circle z and update the total service bandwidth of link e to be protected to x e ;

[0043] 4.3. If the total service bandwidth of the selected link is x e > 0, the candidate preset circle set Z is selected in descending order of the number of links on its own circle, and the total service bandwidth x of the selected link is selected. e Provides a target preset circle z for protecting resources;

[0044] 4.4. All selected target preset circles z are organized into a set to obtain the target preset circle set Z. * .

[0045] In the above-mentioned method for allocating protection resources in a space-division multiplexing optical network based on preset circles, in step 4.2, the target preset circle set is set to Z*. If Z* is not empty, then the total service bandwidth x of the selected link is selected from Z*. e Provide protection for the target preset circle z and update the total service bandwidth of link e to be protected to x e , specifically:

[0046] Assume that the target preset circle z is the total service bandwidth x of the selected link e The protection resources provided are at this time:

[0047] like This means that the target preset circle z can be x e Provide sufficient protection resources, update x e =0;

[0048] like This means that the target preset circle z cannot be x e Provide adequate protection resources, update

[0049] Wherein, Z*∈Z indicates that the target preset circle set Z* is selected from the candidate preset circle set Z, and z∈Z* is an element of Z*.

[0050] In the above-mentioned method for allocating protection resources in a space-division multiplexing optical network based on a preset circle, in step 4.3, if the total service bandwidth of the selected link is x e > 0, the candidate preset circle set Z is selected in descending order of the number of links on its own circle, and the total service bandwidth x of the selected link is selected. e Provide a target preset circle z for protecting resources. The specific steps are:

[0051] 4.3.1. The candidate preset circle set Z is sorted in descending order by the number of links on its own circle. Let each target preset circle z be the total service bandwidth x of the selected links. e The protection resources provided are Idle protection resources are

[0052] 4.3.2. Obtain the total service bandwidth x of the selected link e , confirm that the selected link is the link on the target preset circle z, or a cross link;

[0053] 4.3.3、If it is a circle link, set x e with y e Compare the sizes and select the target preset circle z;

[0054] 4.3.4、If it is a cross link, with y e Compare the sizes and select the target preset circle z.

[0055] In the above-mentioned method for allocating protection resources of space-division multiplexing optical network based on preset circles, in step 4.3.3, if it is a circle uplink, x e with y e Compare the sizes and select the target preset circle z, specifically:

[0056] If x e <y e , indicating that the protection resources provided by the current target preset circle z can fully protect x e , that is, the target preset circle z is successfully selected;

[0057] And the target preset circle z is x e Protection resources provided

[0058] The target preset circle z is x e Idle protection resources provided

[0059] Update the available idle protection resources on the currently selected link

[0060] Among them, if x e >y e , indicating that the protection resources provided by the current target preset circle z cannot fully protect x e , can only provide y e conservation resources;

[0061] Then the target preset circle z is x e The protection resources provided are

[0062] The target preset circle z is xe The idle protection resources provided are

[0063] Update the available idle protection resources on the currently selected link to

[0064] Reselect other target preset circles z in the candidate preset circle set Z to provide (x e -y e ) until x is met e <y e , successfully selected the target preset circle z.

[0065] In the above-mentioned method for allocating protection resources of space-division multiplexing optical network based on preset circles, in step 4.3.4, if it is a cross link, with y e Compare the sizes and select the target preset circle z, specifically:

[0066] Among them, if Indicates that the current target preset circle z protection resources can fully protect x e , that is, the target preset circle z is successfully selected;

[0067] And the target preset circle z is x e Protection resources provided

[0068] And the target preset circle z is x′ e The idle protection resources provided are

[0069] Updates the total protection resources available on the currently selected link

[0070] Among them, if Indicates that the current target preset circle z protection resources cannot fully protect x e , can only provide 2y e conservation resources;

[0071] Then the target preset circle z is x e The protection resources provided are

[0072] The target preset circle z is x e The idle protection resources provided are

[0073] Update the total protection resources available on the currently selected link to

[0074] Reselect other target preset circles z in the candidate preset circle set Z to provide (xe -2y e ) of the protection resources until the Successfully selected the target preset circle z.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] The present invention generates a set of candidate preset circles based on the total service bandwidth of links in a space-division multiplexing optical network, available idle protection resources, and optical network topology, and determines the protection resources provided by the set. The candidate preset circles generated by this selection method are relatively small in number, high in quality, and have a low algorithm complexity. Then, all target preset circles are selected from the candidate preset circle set in combination with the total service bandwidth of each selected link, ultimately obtaining a target preset circle set. The target preset circle set can protect not only links on the circle but also cross-links, and can also provide protection for other links with smaller total service bandwidths. In other words, the target preset circle set can efficiently allocate protection resources for the space-division multiplexing optical network, achieve high protection resource utilization, meet the protection requirements of all service requests, and achieve high protection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0078] Figure 1 A network topology diagram with six nodes and eight edges according to the present invention;

[0079] Figure 2 Schematic diagram of the structure of three fiber cores in the present invention;

[0080] Figure 3 The present invention is based on Figure 1 Demonstration diagram of the three preset circles generated;

[0081] Figure 4 is a flow chart of the present invention;

[0082] Figure 5 This is a schematic diagram of idle protection resource allocation according to the present invention. DETAILED DESCRIPTION

[0083] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0084] The present invention provides Figure 1-5 The method for allocating protection resources in a space-division multiplexing optical network based on a preset circle includes the following steps:

[0085] Step 1: Obtain the total service bandwidth of service requests in all fiber cores on each link in the space-division multiplexing optical network. The specific steps are as follows:

[0086] 1.1. Let G(V,E,C) be a space-division multiplexing optical network, and R be the set of all service requests in G;

[0087] Where V is the set of nodes in the network topology;

[0088] E is a set of directed links;

[0089] C is the core collection;

[0090] 1.2, set is the bandwidth of r in the cth fiber core on link e;

[0091] Among them, e∈E, is the e-th link in G,

[0092] c∈C, is the c-th fiber core in G,

[0093] r∈R, is the rth service request in G;

[0094] 1.3. The formula for calculating the total service bandwidth of service requests in all fiber cores on each link is as follows:

[0095]

[0096] For example: when the set of all business requests R contains 3 business requests;

[0097] The request r1 is sent from v1 to v3, and the requested bandwidth is 10 units of spectrum resources.

[0098] Request r2, whose source node is v1 and destination node is v4, requests a bandwidth of 5 units of spectrum resources;

[0099] Request r1, whose source node is v2 and destination node is v4, requests a bandwidth of 25 units of spectrum resources;

[0100] At this time, for the set of all business requests R, its business path is as follows Figure 3 As shown, it can be seen that: request r1 passes through the core c3 of link e1 and the core c3 of e2;

[0101] Request r2 passes through the core c3 of link e1, the core c3 of e2, and the core c3 of e3;

[0102] Request r3 passes through the core c1 of the core of link e4;

[0103] Therefore, the service bandwidth contained in the third fiber core on link e1, that is, the bandwidth of service request r1, can be expressed as The service bandwidth that needs to be protected is 10 units of spectrum resources;

[0104] The bandwidth of service request r2 can be expressed as The service bandwidth that needs to be protected is 5 units of spectrum resources;

[0105] The service bandwidth contained in the third fiber core on link e2, that is, the bandwidth of service request r1, can be expressed as The service bandwidth that needs to be protected is 10 units of spectrum resources;

[0106] The bandwidth of service request r2 can be expressed as The service bandwidth that needs to be protected is 5 units of spectrum resources;

[0107] The service bandwidth contained in the third fiber core on link e3, that is, the bandwidth of service request r2, can be expressed as The service bandwidth that needs to be protected is 5 units of spectrum resources;

[0108] The service bandwidth contained in the first fiber core on link e4, that is, the bandwidth of service request r3, can be expressed as The service bandwidth that needs to be protected is 25 units of spectrum resources;

[0109] The service bandwidth contained in the third fiber core on link e1 is:

[0110] The service bandwidth contained in the third fiber core on link e2 is:

[0111] The service bandwidth contained in the third fiber core on link e3 is:

[0112] Then the service bandwidth contained in the third fiber core on link e4 is:

[0113] That is, link e1: x1 = 15; link e2: x2 = 15; link e3: x3 = 5; link e4: x4 = 25;

[0114] From the above, we can derive the above calculation formula for the total service bandwidth of service requests in all fiber cores on each link.

[0115] In this step, by calculating the service bandwidth of all service requests in the links and fiber cores passed through their service paths, the total service bandwidth of the service requests in all fiber cores on each link in the spatial division multiplexing optical network is obtained, and the total service bandwidth on the link is protected as a whole in the preset circle, and the total service bandwidth in the link that needs to be protected by the preset circle is clarified.

[0116] Step 2: Set y e It is the idle protection resource available on each link in the space-division multiplexing optical network;

[0117] Among them, the idle protection resource set of each link in the space-division multiplexing optical network is F,

[0118] And f∈F, is the fth spectrum resource on each link,

[0119] |F| is the maximum idle protection resource on each link;

[0120] Among them, the idle protection resource y on each link e Less than the maximum idle protection resource |F| on each link, that is:

[0121] y e ≤|F|;

[0122] In this step, available idle protection resources on each link of the spatial division multiplexing optical network, ie, the number of available spectrum resources on each link, are obtained, thereby providing available idle protection resources for protection resource allocation of the preset circle in subsequent steps.

[0123] Step 3: Based on the total service bandwidth of the link, available idle protection resources, and the optical network topology, a candidate preset circle set is generated and the protection resources provided by it are determined. The specific steps are as follows:

[0124] The network topology includes a set of nodes and a set of directed links in the optical network topology;

[0125] 3.1. Arrange all links in the space-division multiplexing optical network in descending order according to their total service bandwidth;

[0126] 3.2. Within a link, select any node v at both ends of the link in descending order and perform a depth-first search to obtain all possible set circles Q with both starting and ending points v and a path length greater than 3. Then sort the set circles Q in ascending order according to their path lengths.

[0127] Among them, v∈V is a node in the network topology;

[0128] 3.3. Select the single circle q in ascending order. If the available idle protection resources of the single circle q can provide protection for the link, select it as the candidate preset circle;

[0129] Among them, q∈Q is a circle in the set circle Q;

[0130] The available idle protection resources of a single circle q are the minimum available idle protection resources of all links constituting the single circle q.

[0131] 3.4. Repeat steps 3.2-3.3 for the remaining links, and organize the selected candidate preset circles to generate a candidate preset circle set Z;

[0132] 3.5. Based on the candidate preset circle set Z, determine the protection resources it provides, specifically:

[0133] When the candidate preset circle set Z is determined, the protection resources it provides are all circle links and all cross links;

[0134] The services that can be protected by the candidate preset circle set Z include: all circle uplinks constituting the candidate preset circle set Z and the cross-links formed by all nodes of the candidate preset circle set Z;

[0135] For example: Figure 3 As shown, there are three candidate preset circles z, namely z1, z2, and z3. Figure 3 It can be concluded that the links on the preset circle z1 include e1, e2, e3, e5, e7, and e8;

[0136] The links on the preset circle z2 include e1, e4, e5, and e6;

[0137] The links on the preset circle z3 include e2, e3, and e4;

[0138] The preset circle z1 can protect the cross-links e4, e6, and the links on the circle e1, e2, e3, e5, e7, and e8;

[0139] The preset circle z2 can only protect the links e1, e4, e5, and e6 on the circle;

[0140] The preset circle z3 can only protect the links e2, e3, and e4 on the circle;

[0141] The protection resources provided by the preset circle z1 for the cross-links e4 and e6 are twice as much as those provided by the links e1, e2, e3, e5, e7, and e8 on the circle;

[0142] In this step, links with large total service bandwidth are first considered. Based on the optical network topology, all single circles q that can provide protection for these links are generated to obtain a set circle Q. Then, all single circles q are screened based on the length of the set circle Q and the available idle protection resources to obtain candidate preset circles. This method not only considers the optical network topology, but also the total service bandwidth and available idle protection resources on the link, avoiding the generation of a large number of candidate preset circles. This effectively reduces the complexity of the algorithm while ensuring the quality of the candidate preset circles.

[0143] At the same time, the protection resources provided by the candidate preset circle set Z for the cross-link are twice the protection resources provided by the set circle Q on the link, which can better provide protection resources for the cross-link.

[0144] Step 4: Determine the target preset circle based on the total service bandwidth and the protection resources provided by the candidate preset circle set. The specific steps are as follows:

[0145] 4.1. Total bandwidth of services on all links x e Sort in descending order and select each link in turn according to the sorting;

[0146] Example: When the links are sorted in descending order according to their total service bandwidth, we can get:

[0147] Link e4: x4 = 25. This means that when link e4 is selected, the total service bandwidth to be protected is 25.

[0148] Link e1: x1 = 15. This means that when link e1 is selected, the total service bandwidth to be protected is 15.

[0149] Link e2: x2 = 15. This means that when link e2 is selected, the total service bandwidth to be protected is 15.

[0150] Link e3: x3 = 5. This means that when link e3 is selected, the total service bandwidth to be protected is 5.

[0151] 4.2. Let the target preset circle set be Z*. If Z* is not empty, then select the service total bandwidth x of the selected link in Z*. e Provide protection for the target preset circle z and update the total service bandwidth of link e to be protected to x e , specifically:

[0152] Assume that the target preset circle z is the total service bandwidth x of the selected link e The protection resources provided are At this time, if This means that the target preset circle z can be x e Provide sufficient protection resources, update x e =0;

[0153] like This means that the target preset circle z cannot be x e Provide adequate protection resources, update

[0154] Where Z*∈Z indicates that the target preset circle set Z* is selected from the candidate preset circle set Z, and z∈Z* is an element of Z*;

[0155] 4.3. If the total service bandwidth of the selected link is x e > 0, the candidate preset circle set Z is selected in descending order of the number of links on its own circle, and the total service bandwidth x of the selected link is selected. e Provide a target preset circle z for protecting resources. The specific steps are:

[0156] 4.3.1. The candidate preset circle set Z is sorted in descending order by the number of links on its own circle. Let each target preset circle z be the total service bandwidth x of the selected links. e The protection resources provided are Idle protection resources are

[0157] 4.3.2. Obtain the total service bandwidth x of the selected link e , confirm that the selected link is the link on the target preset circle z, or a cross link;

[0158] 4.3.3、If it is a circle link, set x e with y e Compare the sizes and select the target preset circle z, specifically:

[0159] If x e <y e , indicating that the protection resources provided by the current target preset circle z can fully protect x e , that is, the target preset circle z is successfully selected;

[0160] And the target preset circle z is x e Protection resources provided

[0161] The target preset circle z is x e Idle protection resources provided

[0162] Update the available idle protection resources on the currently selected link

[0163] Among them, if x e >y e , indicating that the protection resources provided by the current target preset circle z cannot fully protect x e, can only provide y e conservation resources;

[0164] Then the target preset circle z is x e The protection resources provided are

[0165] The target preset circle z is x e The idle protection resources provided are

[0166] Update the available idle protection resources on the currently selected link to

[0167] At this time, reselect other target preset circles z in the candidate preset circle set Z to provide (x e -y e ) until x is met e <y e , successfully selected the target preset circle z;

[0168] 4.3.4、If it is a cross link, with y e Compare the sizes and select the target preset circle z, specifically:

[0169] like Indicates that the current target preset circle z protection resources can fully protect x e , that is, the target preset circle z is successfully selected;

[0170] And the target preset circle z is x e Protection resources provided

[0171] The target preset circle z is x′ e The idle protection resources provided are

[0172] Updates the total protection resources available on the currently selected link

[0173] Among them, if Indicates that the current target preset circle z protection resources cannot fully protect x e , can only provide 2y e conservation resources;

[0174] Then the target preset circle z is x e The protection resources provided are

[0175] The target preset circle z is x e The idle protection resources provided are

[0176] Update the total available protection resources on the currently selected link to

[0177] At this time, reselect another target preset loop z in the candidate preset loop set Z to provide protection resources of (x e - 2y e ) for this selected link until it meets Successfully select the target preset loop z;

[0178] For example: in Figure 3 , assume y e ≤ |F| = 50;

[0179] Select link e4, the total service bandwidth it needs to protect is x4 = 25 > 0. The target preset loops that can provide protection for e4 are z1, z2, z3. Then compare the number of links on the preset loops z1, z2, z3;

[0180] Among them, the links on the preset loop z1 include e1, e2, e3, e5, e7, e8, with a total of 6;

[0181] The links on the preset loop z2 include e1, e4, e5, e6, with a total of 4;

[0182] The links on the preset loop z3 include e2, e3, e4, with a total of 3;

[0183] Obtain the minimum available protection resource among all the links on the current preset loop z3 as y = min{y2, y3, y4} = 50; <0000​​​​​​​​​​​​​​

[0186] Among them, the on-loop links of the preset loop z1 include e1, e2, e3, e5, e7, e8, with a total of 6;

[0187] The on-loop links of the preset loop z2 include e1, e4, e5, e6, with a total of 4;

[0188] At this time, in descending order according to the number of on-loop links of the preset loop, the descending order result is the preset loops z2 and z1,

[0189] Calculate that the smallest available idle protection resource among all the on-loop links of the preset loop z2 is y = min{y1, y4, y5, y6} = 25, and the link e1 is an on-loop link of the preset loop z2;

[0190] Furthermore, compare the magnitudes of x1 = 15 and y = 25. It is found that x1 < y, indicating that the current protection resource can fully protect x1. Then the protection resource provided by the preset loop z2 for e1 And the idle protection resource provided by the preset loop z2 for x1 Update the available idle protection resources of the on-loop links e1, e4, e5, e6 of the preset loop z2 At this time, the preset loop z2 can be selected as the target preset loop;

[0191] Subsequently, select the link e2 in sequence. The total bandwidth of the service it needs to protect is x2 = 15. Since the preset loop set Z * is a non-empty set, which includes the preset loops z3 and z2, and the preset loop z3 can provide protection resources for the link e2;

[0192] At this time, compare the magnitudes of x2 and the protection resources that the preset loop z3 can provide The idle protection resource already allocated for the preset loop z3 is 25, and the link e2 is an on-loop link of the preset loop z3:

[0193] Then It means that the preset loop z3 can provide sufficient protection resources for x2, and update x2 = x2 - x2 = 0;

[0194] Then, select the link e3 in sequence. The total bandwidth of the service it needs to protect is x3 = 5. Since the preset loop set Z * is a non-empty set, including the preset loops z3 and z2, and the preset loop z3 can provide protection resources for the link e3:

[0195] At this time, compare the magnitudes of x3 and the protection resources that the preset loop z3 can provide The idle protection resource already allocated for the preset loop z3 is 25, and the link e3 is an on-loop link of the preset loop z3:

[0196] Then Indicates that the preset circle z3 can provide sufficient protection resources for x3, and updates x3 = x3 - x3 = 0;

[0197] At this time, the preset circle z3 can be selected as the target preset circle;

[0198] 4.4. All selected target preset circles z are organized into a set to obtain the target preset circle set Z. * ;

[0199] like Figure 5 As shown, the target preset circles z3 and z2 required to protect all services r on all fiber cores c on all links e are obtained, and the idle protection resources of the target preset circle z3 are 25, and the idle protection resources of the target preset circle z2 are 15;

[0200] In this step, a target candidate circle is selected from the candidate preset circle set based on the total service bandwidth of the link. The target candidate circle can initially provide protection for links with larger total service bandwidths. Based on the protection characteristics of the preset circle, the selected target preset circle can also provide protection for other links with smaller total service bandwidths (as long as the link is an on-link or cross-link of the target preset circle), thereby improving the protection efficiency of the target preset circle.

[0201] In the process of selecting the target preset circle, the number of links on the circle is fully considered. The fewer the number of links on the circle, the fewer the idle protection resources allocated to all the links on the target preset circle, and the fewer the total idle protection resources allocated in the spatial division multiplexing optical network. As a result, the protection of the selected target preset circle can protect not only the links on the circle, but also the cross-links, with higher protection efficiency.

[0202] At the same time, when selecting a target preset circle, the idle protection resource utilization rate of the target preset circle is further improved by sorting the total bandwidth of services in all fiber cores of all services on the link.

[0203] In summary, the present invention generates a set of candidate preset circles based on the total service bandwidth of the links in the space-division multiplexing optical network, the available idle protection resources, and the optical network topology, and determines the protection resources provided by them. The candidate preset circles generated by this selection method are small in number, high in quality, and low in algorithm complexity. Then, all target preset circles are selected from the candidate preset circle set in combination with the total service bandwidth of each selected link, and finally a target preset circle set is obtained. This target preset circle set can not only protect the links on the circle, but also protect the cross-links, and can also provide protection for other links with smaller total service bandwidths, that is, the target preset circle set Z. *It can efficiently allocate protection resources to the space-division multiplexing optical network, with high protection resource utilization, which can meet the protection requirements of all business requests and has high protection efficiency. At the same time, because protection resources have been configured for the protected loop links and cross-links, the protection time during fault recovery is relatively short.

[0204] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A method for allocating protection resources in a space-division multiplexing optical network based on a preset circle, characterized by: The following steps are involved: Step 1: Obtain the total service bandwidth of service requests in all fiber cores on each link in the space-division multiplexing optical network. The specific steps are as follows: 1.

1. Let G(V,E,C) be a space-division multiplexing optical network, and R be the set of all service requests in G; 1.2, set is the bandwidth of r in the cth fiber core on link e; 1.

3. The formula for calculating the total service bandwidth of service requests in all fiber cores on each link is as follows: Step 2: Set y e It is the idle protection resource available on each link in the space-division multiplexing optical network; Step 3: Based on the total service bandwidth of the link, available idle protection resources, and the optical network topology, a candidate preset circle set is generated and the protection resources provided by the candidate preset circle set are determined, including the following steps: 3.

1. Arrange all links in the space-division multiplexing optical network in descending order according to their total service bandwidth; 3.

2. Within a link, select any node v at both ends of the link in descending order and perform a depth-first search to obtain all possible set circles Q with both starting and ending points v and a path length greater than 3. Then sort the set circles Q in ascending order according to their path lengths. Among them, v∈V is a node in the network topology; Step 4: Determine the target preset circle based on the total service bandwidth and the protection resources provided by the candidate preset circle set. The specific steps are as follows: 4.

1. Total bandwidth of services on all links x e Sort in descending order and select each link in turn according to the sorting; 4.

2. Let the target preset circle set be Z*. If Z* is not empty, then select the service total bandwidth x of the selected link in Z*. e Provide protection for the target preset circle z and update the total service bandwidth of link e to be protected to x e ; 4.

3. If the total service bandwidth of the selected link is x e > 0, the candidate preset circle set Z is selected in descending order of the number of links on its own circle, and the total service bandwidth x of the selected link is selected. e Provide a target preset circle z for protecting resources. The specific steps are: 4.3.

1. The candidate preset circle set Z is sorted in descending order by the number of links on its own circle. Let each target preset circle z be the total service bandwidth x of the selected links. e The protection resources provided are Idle protection resources are 4.3.

2. Obtain the total service bandwidth x of the selected link e , confirm that the selected link is the link on the target preset circle z, or a cross link; 4.3.3、If it is a circle link, set x e with y e Compare the sizes and select the target preset circle z; 4.3.4、If it is a cross link, with y e Compare the sizes and select the target preset circle z; 4.

4. All selected target preset circles z are organized into a set to obtain the target preset circle set Z. * .

2. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 1.1, V is the set of nodes in the network topology; E is a set of directed links; C is the core collection; In step 1.2, e∈E, is the e-th link in G; c∈C, is the c-th fiber core in G; In step 1.3, r∈R is the rth service request in G.

3. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 2, Among them, the idle protection resource set of each link in the space-division multiplexing optical network is F, And f∈F, is the fth spectrum resource on each link, |F| is the maximum idle protection resource on each link; Among them, the available idle protection resources y on each link e Less than the maximum idle protection resource |F| on each link, that is: y e ≤|F|。 4. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 3, based on the total service bandwidth of the link, available idle protection resources, and the optical network topology, a candidate preset circle set is generated and the protection resources provided by the candidate preset circle set are determined, which also includes the following steps: 3.

3. Select the single circle q in ascending order. If the idle protection resources of the single circle q can provide protection for the link, select it as the candidate pre-set circle; Among them, q∈Q is a circle in the set circle Q; 3.

4. Repeat steps 3.2-3.3 for the remaining links, and organize the selected candidate preset circles to generate a candidate preset circle set Z; 3.

5. Based on the candidate preset circle set Z, determine the protection resources provided by it.

5. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 4, characterized in that: In step 3.5, based on the candidate preset circle set Z, the protection resources provided by it are determined, specifically: When the candidate preset circle set Z is determined, the protection resources it provides are all circle links and all cross links; The services that can be protected by the candidate preset circle set Z include: all circle uplinks constituting the candidate preset circle set Z and cross-links formed by all nodes of the candidate preset circle set Z.

6. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 4.2, let the target preset circle set be Z*. If Z* is not empty, select the service total bandwidth x of the selected link in Z*. e Provide protection for the target preset circle z and update the total service bandwidth of link e to be protected to x e , specifically: Assume that the target preset circle z is the total service bandwidth x of the selected link e The protection resources provided are at this time: like This means that the target preset circle z can be x e Provide sufficient protection resources, update x e =0; like This means that the target preset circle z cannot be x e Provide adequate protection resources, update Wherein, Z*∈Z indicates that the target preset circle set Z* is selected from the candidate preset circle set Z, and z∈Z* is an element of Z*.

7. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 4.3.3, if it is a circle link, set x e with y e Compare the sizes and select the target preset circle z, specifically: If x e <y e , indicating that the protection resources provided by the current target preset circle z can fully protect x e , that is, the target preset circle z is successfully selected; And the target preset circle z is x e Protection resources provided The target preset circle z is x e Idle protection resources provided Update the available idle protection resources on the currently selected link Among them, if x e >y e , indicating that the protection resources provided by the current target preset circle z cannot fully protect x e , can only provide y e conservation resources; Then the target preset circle z is x e The protection resources provided are The target preset circle z is x e The idle protection resources provided are Update the available idle protection resources on the currently selected link to Reselect other target preset circles z in the candidate preset circle set Z to provide (x e -y e ) until x is met e <y e , successfully selected the target preset circle z.

8. The method for allocating protection resources in a spatial division multiplexing optical network based on a preset circle according to claim 1, characterized in that: In step 4.3.4, if it is a cross link, with y e Compare the sizes and select the target preset circle z, specifically: Among them, if Indicates that the current target preset circle z protection resources can fully protect x e , that is, the target preset circle z is successfully selected; And the target preset circle z is x e Protection resources provided And the target preset circle z is x′ e The idle protection resources provided are Updates the total protection resources available on the currently selected link Among them, if Indicates that the current target preset circle z protection resources cannot fully protect x e , can only provide 2y e conservation resources; Then the target preset circle z is x e The protection resources provided are The target preset circle z is x e The idle protection resources provided are Update the total protection resources available on the currently selected link to Reselect other target preset circles z in the candidate preset circle set Z to provide (x e -2y e ) of the protection resources until the Successfully selected the target preset circle z.

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