FSDM network limited uplink and downlink port dynamic survival optical path configuration method and system

Abstract

The invention relates to the field of network resource allocation, in particular to an FSDM network limited uplink and downlink port dynamic survival optical path configuration method and system, and the method comprises the steps: constructing an FSDM optical network employing a shared laser source and a local oscillator, building an analytical model, and predicting the network blocking performance under the condition of different numbers of uplink and downlink ports of optical cross connection nodes, determining a port threshold; and on the basis of a port threshold value, whether an idle uplink and downlink port exists in a source node and a destination node or not is firstly judged through a constructed adaptive routing algorithm, and then working and protection path search is started, so that FSDM optical network dynamic survival optical path configuration based on shared backup path protection is realized. According to the FSDM optical network protection strategy, the blank of the FSDM optical network protection strategy is filled, the analytical model can reduce redundant configuration and optimize the network cost, the adaptive routing algorithm can improve the spectrum utilization efficiency, and the medium Spa SCh granularity configuration is adopted, so that the FSDM network has high cost benefit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of network resource allocation, in particular to a FSDM network limited add-drop port dynamic survivable optical path configuration method and system. BACKGROUND

[0002] In recent years, space division multiplexing (SDM) combined with super channel (SCh) technology has gradually become a research and development potential scheme to enhance the capacity of optical networks. Among them, the super channel technology, as a new technology emerging in recent years, can construct optical channels in the same spectrum of different optical fibers, thereby efficiently carrying data transmission; and the SDM technology is mainly realized through two ways, namely, MCF-SDM based on multi-core fiber and fiber space division multiplexing (FSDM).

[0003] Specifically, MCF-SDM uses multi-core fiber as the transmission medium, but its application range is not extensive at present, and the key problem of crosstalk between cores needs to be solved at the technical level, otherwise it will seriously affect the transmission quality. Compared with MCF-SDM, FSDM technology has obvious practical advantages: on the one hand, relying on a large number of SSMF optical cable resources already buried underground, FSDM can create super channels by combining the same spectrum on multiple optical fibers, without the need for large-scale new infrastructure; on the other hand, FSDM can share common laser sources (LS) and local oscillators (LO), so that signals on different optical fibers can run on the same spectrum, which not only greatly reduces the system design complexity, construction cost and energy consumption, but also fundamentally avoids the crosstalk problem between cores in MCF-SDM, so it has higher feasibility in practical application.

[0004] At present, the research on MCF-SDM in the field of optical networks is relatively extensive, covering efficient resource allocation strategies, switching technologies and other directions, and the core focus is on establishing variable bandwidth optical channels within a single optical fiber, and the influence of crosstalk between adjacent cores and non-adjacent cores needs to be considered in the design process. But as a new SDM technology, FSDM-related research is still relatively scarce, especially in network survivability and resource configuration optimization.

[0005] The existing public technology has not carried out targeted research on the characteristics of FSDM network, resulting in two key problems: The first is the lack of research on the survivability of FSDM network. Since a single link failure will affect all optical fibers in an optical cable, it is easy to cause serious communication interruption, but there is no research on this survivability challenge of FSDM network, and no protection technology (such as shared backup path protection) is introduced into FSDM optical network to avoid failure risk, and there is also a lack of supporting resource optimization allocation scheme. Secondly, most existing researches assume that the optical cross-connect (OXC) node has a complete set of add / drop ports, ignoring the scenario that a large number of light paths in the actual optical transmission network only need to be forwarded through the node without the need for adding / dropping, and not considering the constraint of limited add / drop ports, resulting in that the related technical solutions have extremely low cost-effectiveness in actual application and are difficult to promote. SUMMARY

[0006] Therefore, the technical problem to be solved by the present application is how to realize dynamic survivable light path configuration based on the shared backup path protection (SBPP) technology in the fiber space division multiplexing (FSDM) based optical network, in view of the actual constraint of limited add / drop ports of the optical cross-connect (OXC) node, while solving the add / drop port, routing, fiber and spectrum allocation (A / DPRFSA) problem and accurately predicting the network blocking performance, so as to balance the network survivability, resource utilization and cost-effectiveness.

[0007] To solve the above technical problems, the present application provides a method and system for dynamic survivable light path configuration with limited add / drop ports in FSDM network. S1: constructing an FSDM optical network using a shared laser source and a local oscillator, wherein each link in the FSDM optical network comprises a link fiber bundle composed of multiple optical fibers, the link fiber bundle shares the laser source and the local oscillator, and the optical cross-connect node is configured with a limited number of add / drop ports; S2: establishing a spectral slot block based analytical model to predict the network blocking performance under different numbers of add / drop ports of the optical cross-connect node, and determining the add / drop port threshold of the optical cross-connect node; S3: constructing an adaptive routing algorithm based on a spectral slot block bundle plane, based on the add / drop port threshold, determining whether there are idle add / drop ports between the source node and the destination node through the adaptive routing algorithm, to start the search of the working path and the protection path, and realizing the dynamic survivable light path configuration of the FSDM optical network based on the shared backup path protection.

[0008] In one embodiment of the present application, in S1, the number of link fiber bundles in the FSDM optical network is satisfies: wherein F is the total number of optical fibers contained in each link in the FSDM optical network, g is the spatial superchannel granularity of the FSDM optical network, i.e. the total number of optical fibers contained in each link fiber bundle; and each optical fiber constituting the link fiber bundle contains o spectral slots, and the spectral slot block formed by the link fiber bundle has a size of g x o spectral slots.

[0009] In one embodiment of the present application, in S2, the method for determining the add / drop port threshold of the optical cross-connect node is as follows: For the target optical cross-connect node, the number of add / drop ports is gradually increased from the minimum port number, and the total network blocking probability is recalculated through the analysis model each time the port number is increased; When the following two conditions are met, the current number of add / drop ports is the add / drop port threshold: Condition one: the total network blocking probability reaches a saturation point, that is, when the number of add / drop ports is increased, the total network blocking probability no longer changes; Condition two: the total network blocking probability caused by insufficient number of add / drop ports is less than or equal to a preset threshold, at which time the blocking caused by insufficient number of add / drop ports accounts for a negligible proportion in the total network blocking probability, and the total network blocking probability is mainly caused by insufficient spectrum slot capacity.

[0010] In one embodiment of the present application, in S2, the method for calculating the total network blocking probability is as follows: Calculate the utilization rate of a single add / drop port of any optical cross-connect node : , wherein is the link fiber bundle utilization rate, is the service add / drop ratio, is the system add / drop ratio; Based on the utilization rate , the probability that ports in the source node are all occupied is , and the probability that ports in the destination node are all occupied is ; According to the and the , the total network blocking probability, that is, the blocking probability caused by limited spectrum slot capacity is obtained: , wherein is the spectrum slot blocking probability on the link fiber bundle.

[0011] In one embodiment of the present application, the calculation method of the spectrum slot blocking probability on the link fiber bundle is as follows: A backup capacity sharing coefficient is introduced to describe the sharing efficiency of the link fiber bundle, and the spectrum slot blocking probability on the link fiber bundle is calculated: ; and wherein, the utilization of link fiber bundles, the number of link fiber bundles, the average number of spectral slot bundles on each link, H is the average hop number of working or protection light paths.

[0012] In an embodiment of the present application, the method for calculating the system up-down ratio is as follows: the actual number of system up-down ports deployed on the node, denotes the average node degree of the network, the average number of spectral slot bundles on each link, denotes the total number of spectral slots incident on the node.

[0013] In an embodiment of the present application, the method for calculating the traffic up-down ratio is as follows: the actual total number of up-down light paths on the node, denotes the average node degree of the network, the average number of spectral slot bundles on each link, denotes the total number of spectral slots of effective light paths carried on all incident links of the node.

[0014] In an embodiment of the present application, in S3, based on the up-down port threshold, the idle up-down ports of the source node and the destination node are first judged by the adaptive routing algorithm to start the search of the subsequent working path and protection path, and the method for realizing the dynamic survival light path configuration of the FSDM optical network based on the shared backup path protection is as follows: S31: the up-down ports of the source node and the destination node are respectively detected for the idle state: if any node has no idle port, the current service request is terminated and marked as blocked; if both nodes have idle ports, the search counter k = 1 is initialized; S32: according to the number of spectral slot blocks required by the current service request and the network configuration parameters, a candidate spectral slot block bundle plane set is generated, the network physical topology link is copied, all spectral slot block bundle links marked as busy are removed, and if all spectral slots of any link are in the busy state, the link is removed from the current spectral slot block bundle plane; S33: based on the candidate spectral slot block bundle plane set, the working path from the source node to the destination node is searched in the Kth spectral slot block bundle plane: if the working path is searched, step S34 is entered to perform the protection path search step; ​​​​If not, the value of the search counter k is incremented by one, and step S35 is entered; S34: In the Kth spectrum slot bundle plane, remove the spectrum slot bundle links that do not meet the shared backup path protection capacity sharing rule, and search for a protection path from the source node to the destination node among the remaining spectrum slot bundle links: If the protection path is found, select an idle spectrum slot bundle on the spectrum slot bundle link corresponding to the working path and the protection path, and update the state of the selected spectrum slot bundle to busy, and then enter step S36; If not, the value of the search counter k is incremented by one, and step S33 is executed again; S35: Determine whether k is less than or equal to the average number of spectrum slot bundles per link: If yes, return to step S33; If no, determine that the current service request is blocked, and then enter step S36; S36: Check whether all service requests have completed routing and resource allocation: If yes, calculate and compute the network blocking probability; If not, switch to the next unprocessed service request, and return to step S31.

[0015] In an embodiment of the present application, in S32, the method for generating the candidate spectrum slot bundle plane set is as follows: S321: Based on the physical link of the FSDM optical network, copy the connection relationship of all nodes and links to obtain a spectrum slot bundle composed of all spectrum slot sets on a group of virtual links, and group all virtual links in sequence to form an initial spectrum slot bundle plane; S322: According to the number of spectrum slots required by the current service request, perform state detection on all spectrum slot bundles in the initial spectrum slot bundle plane: In the initial spectrum slot bundle plane, retain all spectrum slot bundles containing at least the number of idle spectrum slots required by the current service request, remove all spectrum slot bundles whose all spectrum slots are occupied, and if all spectrum slot bundles on any virtual link are removed, remove the link from the corresponding spectrum slot bundle plane, to obtain a candidate spectrum slot bundle plane set.

[0016] Based on the same inventive concept, the present application also provides a FSDM network limited add / drop port dynamic survival optical path configuration system, which comprises a network construction module, an analysis calculation module and a resource configuration module. The network construction module is configured to construct a FSDM optical network using a shared laser source and a local oscillator, wherein each link of the FSDM optical network comprises a link fiber bundle composed of a plurality of optical fibers, the link fiber bundle shares the laser source and the local oscillator, and an optical cross-connect node is configured with a limited number of add / drop ports. The analysis calculation module is configured to establish a spectrum slot block-based analysis model, and predict the network blocking performance of different optical cross-connect nodes under the number of add / drop ports of the optical cross-connect nodes through the analysis model, and determine the add / drop port threshold of the optical cross-connect nodes. The resource configuration module is configured to construct an adaptive routing algorithm based on a spectrum slot block bundle plane, and based on the add / drop port threshold, determine whether there are idle add / drop ports between a source node and a destination node through the adaptive routing algorithm, so as to start the search of subsequent working paths and protection paths, and realize the dynamic survivable optical path configuration of the FSDM optical network based on shared backup path protection.

[0017] The above technical solutions of the present application have the following beneficial effects compared with the prior art: First, by constructing a FSDM optical network architecture using a shared laser source and a local oscillator, the existing large number of buried standard single-mode optical fibers are fully utilized, and the inter-core crosstalk problem of multi-core optical fibers is avoided, and the shared laser source and the local oscillator greatly reduce the system design cost and energy consumption. Second, the proposed spectrum slot block-based analysis model can accurately predict the network blocking performance under different numbers of add / drop ports of optical cross-connect (OXC) nodes, and further determine the add / drop port threshold of the OXC nodes, effectively reducing the redundant add / drop port configuration, optimizing the network design cost, and the model is verified to be effective by comparison with simulation results. Third, the constructed adaptive routing algorithm based on a spectrum slot block bundle plane, under the premise of shared backup path protection (SBPP), first determines the idle add / drop port state between a source node and a destination node to start the subsequent path search, which significantly reduces the network blocking probability compared with the fixed routing scheme, and provides an efficient survivability solution for the add / drop port, routing, optical fiber and spectrum allocation (A / DPRFSA) problem under different spatial super channel (Spa SCh) granularity, and guarantees the service continuity of the FSDM network in the case of single-link failure. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the accompanying drawings.

[0019] Figure 1 is a flowchart of a FSDM network limited add / drop port dynamic survivable optical path configuration method provided in an embodiment of the present application. Figure 2 FSDM optical network system under different fiber and spectrum combinations, wherein (a) represents that one pair of transceiver systems is used for each fiber, (b) represents that two fibers share one pair of transceiver systems, and (c) represents that four fibers share one pair of transceiver systems; Figure 3 Waste of frequency slots caused by different spectrum slot blocks accommodating one super channel; Figure 4 Traffic demand supply of the FSDM-based optical network, wherein (a) represents a network topology structure, and (b) represents an LFB; Figure 5 Different LFB utilization rates Relationship curve between the two types of add / drop ratios, wherein (a) represents a spatial super channel granularity Different LFB utilization rates Relationship curve between the two types of add / drop ratios; (b) represents a spatial super channel granularity Different LFB utilization rates Relationship curve between the two types of add / drop ratios; (c) represents a spatial super channel granularity Different LFB utilization rates Relationship curve between the two types of add / drop ratios; (d) represents a spatial super channel granularity Different LFB utilization rates Relationship curve between the two types of add / drop ratios; Figure 6 With the increase of the utilization rate of the link fiber bundle , under different Spa SCh granularities, the relationship between the curve slope and the utilization rate of the link fiber bundle is shown in the schematic diagram; Figure 7 Network schematic diagram based on a port add / drop sharing mechanism between working light paths and protection light paths; Figure 8 Test network for performance verification, wherein (a) is a COST239 network, and (b) is an NSFNET network; Figure 9 Under different node pair traffic loads and different Spa SCh granularities, the optical path blocking probability variation trends of the COST239 network and the NSFNET network are shown in (a) and (b), respectively; Figure 10 The structural schematic diagram of a FSDM network limited add / drop port dynamic survival light path configuration system provided in the embodiment of the present application.

[0020] The description reference signs are as follows: 100, network building module; 200, analysis calculation module; 300, resource configuration module. DETAILED DESCRIPTION

[0021] The application will be further described below with reference to the drawings and specific embodiments, so that those skilled in the art can better understand the application and implement it. The embodiments are not intended to limit the application.

[0022] Reference Figure 1 As shown in the drawings, the application provides a FSDM network limited add-drop port dynamic survival optical path configuration method, which aims to solve the dynamic survival optical path configuration problem of the FSDM network under the constraint of limited add-drop ports, and specifically includes the following steps: S1: A FSDM optical network using a shared laser source (LS) and a local oscillator (LO) is built, each link in the FSDM optical network contains a link fiber bundle composed of multiple optical fibers, the link fiber bundle shares the laser source and the local oscillator, and an optical cross-connect node is configured with a limited number of add-drop ports; S2: An analysis model based on a spectrum slot block is established, the network blocking performance under different add-drop port numbers of the optical cross-connect node is predicted through the analysis model, and the add-drop port threshold of the optical cross-connect node is determined; S3: An adaptive routing algorithm based on a spectrum slot block bundle plane is built, based on the add-drop port threshold, whether there is an idle add-drop port between the source node and the destination node is judged through the adaptive routing algorithm, to start the search of the subsequent working path and protection path, and realize the dynamic survival optical path configuration of the FSDM optical network based on shared backup path protection.

[0023] Further, in the FSDM optical network building of step S1, through the shared laser source (LS) and the local oscillator (LO), the same spectrum spatial super channel (Spa SCh) is built on multiple standard single-mode optical fibers (SSMF). Compared with the multi-core fiber (MCF) technology, this architecture can avoid the inter-core crosstalk problem from the root, and significantly reduce the system design complexity, construction cost and energy consumption through hardware resource sharing, which is a key scheme for capacity expansion based on existing buried SSMF cable resources.

[0024] Taking the scenario of a link containing 4 optical fibers as an example, combined with the attached Figure 2 There are three typical LS / LO sharing configuration schemes for the FSDM optical network, and the specific parameters and characteristics are as follows: The first configuration scheme is Figure 2The first configuration scheme is shown in (a) of the accompanying drawings: one set of LS and LO is allocated to each optical fiber, and four sets of transceiver systems are configured. This scheme is essentially consistent with the traditional multi-fiber network architecture, does not take advantage of the hardware sharing of the FSDM, and is only suitable for scenarios with extremely high requirements for transmission independence but not sensitive to cost.

[0025] The second configuration scheme is a double-fiber sharing configuration shown in (b) of the accompanying drawings: one set of LS and LO is shared by two optical fibers, and only two sets of transceiver systems are configured. Under the premise of ensuring the total transmission capacity comparable to that of the independent configuration, the hardware investment is reduced by 50%, achieving a preliminary balance between cost and performance, and being the preferred scheme for small and medium capacity demand scenarios. Figure 2 The third configuration scheme is a full sharing configuration shown in (c) of the accompanying drawings: one set of LS and LO is shared by four optical fibers, and only one set of transceiver systems is configured, with the hardware cost being reduced to the minimum. However, this scheme has higher requirements for spectrum resource planning, and needs to avoid frequency slot waste through fine resource allocation, and is suitable for large-scale centralized business transmission scenarios.

[0026] Figure 2 Based on the above configuration schemes of the FSDM optical network system, several key concepts are defined to clarify the resource allocation logic: A link fiber bundle (LFB) refers to a set of optical fibers sharing one laser source and local oscillator, and is the basic unit of hardware resource sharing in the FSDM network. The number of LFBs is equal to the number of optical fibers in each link.

[0027] Satisfies: wherein F is the total number of optical fibers contained in each link, and g is the spatial superchannel granularity, i.e. the total number of optical fibers contained in each LFB. For example, in the first configuration scheme, when F=4 and g=1, the number of LFBs is i.e. 4 LFBs each containing 1 optical fiber; in the second configuration scheme, when g=2, the number of LFBs is

[0028] 2, i.e. 2 LFBs each containing 2 optical fibers; and in the third configuration scheme, when g=4, the number of LFBs is 1, i.e. 1 LFB each containing 4 optical fibers. A spectrum slot block (FSB) refers to a set of all frequency slots (FS) constituting a spatial superchannel (Spa SCh), and is the basic unit of spectrum resource allocation in the FSDM network. If a single LFB contains g optical fibers, and each optical fiber contains o continuous spectrum slots (FS), then the size (total number of frequency slots) of one FSB is g x o spectrum slots. The core role of the FSB is to integrate the frequency slot resources of multiple optical fibers to meet the bandwidth demand of the Spa SCh, and the size of the FSB needs to match the business bandwidth demand.

[0029] A spectrum slot block (FSB) refers to a set of all frequency slots (FS) constituting a spatial superchannel (Spa SCh), and is the basic unit of spectrum resource allocation in the FSDM network. If a single LFB contains g optical fibers, and each optical fiber contains o continuous spectrum slots (FS), then the size (total number of frequency slots) of one FSB is g x o spectrum slots. The core role of the FSB is to integrate the frequency slot resources of multiple optical fibers to meet the bandwidth demand of the Spa SCh, and the size of the FSB needs to match the business bandwidth demand.

[0030] ​For example, in the three configuration schemes, if you need to build an FSB with a size of 4 FS: In the first configuration scheme, when g=1, a single optical fiber needs to contain 4 FS, which is the number of FSBs. for In the second configuration scheme, when g=2, each fiber needs to contain 2 FS, which is the number of FSBs. for In the third configuration scheme, when g=4, each fiber needs to contain 1 FS, which is the number of FSBs. for .

[0031] The FSDM network adopts a resource allocation principle of 1 Spatial Scholastic Structure (SPA) corresponding to 1 Free Server Branch (FSB), therefore, g×o≥ , The number of frequency slots required for Spatial Scheduling (FSB). When the number of FSBs exceeds service requirements. At times, bandwidth mismatch can lead to wasted frequency slots.

[0032] If the FSB size is 4 FS and the Spa SCh requires 3 FS, then in both the dual-fiber shared (g=2, o=2) and fully shared (g=4, o=1) schemes, 1 FS is wasted; the independent configuration (g=1, o=4) also wastes 1 FS, only when When the value is an integer multiple of g×o, waste-free allocation can be achieved.

[0033] For example Figure 4 Taking the FSDM optical network topology shown as an example, the adaptation process between service requirements and LFB and FSB is explained. The specific parameters and operation logic are as follows: Figure 4 The network topology shown in Figure (a) consists of 6 nodes and 9 links. Each link has a total of 4 optical fibers (F=4), using a dual-fiber shared configuration (g=2). Therefore, the number of LFBs per link is... 2. The two LFBs correspond to fiber pairs (1,2) and (3,4) respectively.

[0034] Suppose a business request r1 requires 3 file systems (FS), and the default route is "node 0 → node 1 → node 2". Figure 4 As shown in (b), for the routing of service request r1, it is necessary to filter for LFBs containing idle frequency slots and satisfying g=2 on both link (node ​​0→node 1) and link (node ​​1→node 2): For the link (node ​​0 → node 1), check the frequency slot occupancy status of the two LFBs. If it is determined that LFB1 (fiber pair 1,2) has an available frequency slot that can accommodate the bandwidth requirement of r1, it is judged as a qualified LFB. For the link (node 1→node 2), LFB2 (fiber pair 3, 4) has free frequency slots, and is determined as a qualified LFB.

[0035] In the qualified LFB, free FSBs satisfying FSB size greater than or equal to 3 FSs are screened: For the qualified LFB1 of the link (node 0→node 1), each fiber contains o FSs, and the FSB size = 2×o, which needs to satisfy 2×o≥3; in combination with the frequency slot occupation, the FSB containing FS6, FS7 (total size = 2×2 = 4 FSs) is screened, which can cover the 3 FS requirement of r1, and is determined as a qualified FSB; For the qualified LFB1 of the link (node 1→node 2), similarly, the FSB containing FS6, FS7 (total size = 4 FSs) is screened, and is determined as a qualified FSB.

[0036] In order to guarantee the transmission stability of the optical path, the FSB spectrum continuity needs to be satisfied, that is, the frequency slot range of the qualified FSB of all links on the route needs to be consistent (such as FS6~FS9). It needs to be noted that the qualified LFB index of different links can be different (such as LFB1 for link 0-1 and LFB2 for link 1-2), and only the frequency slot range of the FSB needs to be unified.

[0037] The set of all qualified LFBs on the route of service r1 is called a route fiber bundle (RFB). In this embodiment, the RFB is composed of LFB1 of link 0-1 and LFB2 of link 1-2, and is the physical carrying carrier of the service optical path, which directly determines the transmission link and resource occupation range of the service.

[0038] The frequency spectrum bin bundle (FSBT) refers to the set of all FSBs on a single link, and if at least one FSB in the FSBT is in a free state, it is marked as “free”; otherwise, it is “busy”.

[0039] Further, in step S2, a spectrum bin-based analysis model (FSB-AM) is established, which mainly considers two types of blocking situations: (1) spectrum bin (FSB) blocking occurs on the link fiber bundle (LFB); (2) the optical cross-connect (OXC) node of the source node or the destination node has no free add / drop port available.

[0040] The method for determining the add / drop port threshold of the optical cross-connect node through the analysis model to predict the network blocking performance under different numbers of add / drop ports of the optical cross-connect node is as follows: For the target optical cross-connect node, start from the minimum number of ports and gradually increase the number of add / drop ports. Each time the port is increased, the total blocking probability of the network is recalculated through the analysis model. The current add-drop port quantity is an add-drop port threshold value when the following two conditions are met: Condition one: the network total blocking probability reaches a saturation point, i.e., the network total blocking probability no longer changes when the add-drop port quantity increases; Condition two: the network total blocking probability caused by insufficient add-drop port quantity is less than or equal to a preset threshold value, at which time the blocking caused by insufficient add-drop port quantity accounts for a negligible proportion in the network total blocking probability, and the network total blocking probability is mainly caused by insufficient spectrum slot capacity.

[0041] Further, in S2, it is assumed that one add / drop port is deployed at each source node and destination node. Considering the availability of the add / drop port, the method for calculating the network total blocking probability is as follows: The utilization rate of a single add / drop port of any optical cross-connect node is calculated as follows: is the link fiber bundle utilization rate, is the service up-down ratio, is the system up-down ratio; Based on the utilization rate , the probability that the ports in the source node are all occupied is calculated as , and the probability that the ports in the destination node are all occupied is calculated as ; According to the and the , the network total blocking probability, i.e., the blocking probability caused by limited spectrum slot capacity, is obtained as follows: is the spectrum slot blocking probability on the link fiber bundle, and the calculation method is as follows: In a shared backup path protection (SBPP) scenario, a backup capacity sharing coefficient is introduced to describe the backup capacity sharing efficiency of the link fiber bundle. In the optical path establishment process of the SBPP mechanism, the working optical path needs to exclusively occupy one complete spectrum slot unit, and the capacity resource of the unit is only for the corresponding working optical path service and does not have the characteristic of sharing with other optical paths. However, the protection optical path has the characteristic of sharing the FSB unit occupied by other protection optical paths under the constraint of the SBPP mechanism, i.e., the same FSB unit can carry the capacity demand of multiple protection optical paths, so the protection optical path actually only consumes part of the capacity resource of the FSB unit. ​​​​​​

[0042] To further clarify the quantitative characterization logic of a, the following is illustrated: if 1 protection capacity unit (corresponding to the part of the FSB unit occupied by the protection optical path for carrying standby capacity) is shared by L protection optical paths, the value of the standby capacity sharing coefficient a is a = 1 / L. The core role of this coefficient is to introduce the fractional utilization characteristics of standby capacity under the SBPP mechanism into the model, realizing quantitative description of standby capacity sharing efficiency.

[0043] In the SBPP scenario, the value range of the standby capacity sharing coefficient a is , and the value of a is negatively related to the sharing efficiency of the SBPP scheme. The smaller a is, the more protection optical paths a single protection capacity unit can share, and the higher the standby capacity sharing efficiency of the SBPP scheme is; the larger a is, the fewer protection optical paths a single protection capacity unit can share, and the lower the standby capacity sharing efficiency of the SBPP scheme is.

[0044] The value of a for special scenarios is defined as follows: a = 0 corresponds to a non-protection scenario; a = 1 corresponds to a 1:1 survivability service configuration, at this time 1 protection capacity unit only serves 1 protection optical path, there is no standby capacity sharing, that is, the standby capacity is in an exclusive state.

[0045] Based on the standby capacity sharing coefficient a , the spectrum slot block probability of the link fiber bundle is calculated : ; Wherein, is the link fiber bundle utilization rate, is the number of link fiber bundles, is the average number of spectrum slot bundles on each link, H is the average number of hops of the working optical path or the protection optical path, is the average number of hops of the working optical path, is the average number of hops of the protection optical path. represents the utilization rate of the first link spectrum block (LFB) in the first link of the service configuration path; similarly, represents the standby capacity sharing coefficient of the first LFB in the first link of the service configuration path. In the formula, the term represents the probability of successfully establishing a pair of working optical path and protection optical path on one common FSBT. Therefore, represents the probability of failing to establish a pair of working optical path and protection optical path on any w FSBTs.

[0046] In the above formula, since the bandwidth of each optical path is a variable size spectral slot block (FSB), not a fixed size wavelength, the number of basic spectral slots (FS) required to define the optical path is η. Based on this, the actual required FS number of any optical path can be expressed as , where τ is a positive integer.

[0047] The FS requirements of all optical path services form a service requirement set δ. Specifically, if the to-be-transmitted optical path service contains n different types, the spectral slot requirements and the proportion of each type of service in set δ satisfy: The proportion is The service needs FS, the proportion is The service needs FS, …, the proportion is The service needs FS; while satisfying two constraint conditions: first, the sum of the proportions of each type of service is 1, that is ; second, the maximum multiplication coefficient satisfies , W represents the number of spectral slots (FS) that a single optical fiber can provide, and g is a spatial spectral channel granularity parameter.

[0048] Based on the above service requirement distribution and constraint conditions, the average required FS number of a single service on a single optical fiber in the LFB can be calculated by weighted summation, and the specific expression is: Further, in combination with the total FS number W of a single optical fiber, the average FSBT number w on each link can be derived, and the expression is: This parameter directly reflects the FSB transmission capacity that can be carried at the link level, and is the core basis for subsequent resource scheduling and blocking probability calculation.

[0049] Further, in this embodiment, for the matching relationship between the add / drop port resources and the spectrum resources of the optical cross-connect (OXC) node, the system up / down ratio and the service up / down ratio are defined. The system up / down ratio is used to represent the matching degree between the number of add / drop port deployments on the OXC node and the total amount of incident spectrum resources of the node, and is defined as the ratio of the actual number of add / drop ports deployed on the node to the average total number of FSBs used by the node, and is expressed as: , is the actual number of system add / drop ports deployed on the node, represents the average node degree of the network, representing the number of incident (or outgoing) links of the OXC node; is the average number of spectral slot beams on each link, corresponding to the total number of FSB transmission units that can be carried by a single link; represents the total number of average spectrum slots incident on the optical cross-connect node; the traffic up / down ratio The traffic up / down ratio is defined as the ratio of the actual number of up / down paths on the node to the total number of paths carried by the node, denoted as: , is the total number of actual up / down paths on the node, represents the total number of spectrum slots carried by all incident links on the node.

[0050] The system up / down ratio and the traffic up / down ratio need to satisfy the Erlang-B formula constraint to ensure that the probability of traffic congestion caused by insufficient up / down port numbers does not exceed the preset upper limit . The constraint relationship is: where B(⋅,⋅) is the Erlang-B formula used to calculate the blocking probability of a multi-server loss system, and its complete expression is: The numerator corresponds to the probability contribution item when all up / down ports are occupied, and the denominator corresponds to the probability sum of port occupation numbers from 0 to the total number of ports.

[0051] Under the given parameters F=6, g={1,2,3,6}, , W=50, and the required FS number of the optical path is randomly generated in the interval [1,7], Figure 5 the different LFB utilization rates The relationship curves between the system up / down ratio and the traffic up / down ratio are shown below. It can be seen that although both satisfy the Erlang-B formula constraint, their relationship is approximately linear. As the LFB utilization rate increases, the curve slope shows a monotonic increasing trend, indicating that the higher the , the greater the change amplitude corresponding to the same

[0052] Figure 6 Further quantifies the relationship between the curve slope in Figure 5 and the LFB utilization rate . It is worth noting that the curve slope and the LFB utilization rate The relationship is also approximately linear; when the spatial superchannel granularity g is coarser, the curve slope is larger, specifically, when g takes values of 1, 2, 3, and 6, the slope values are approximately 1.102, 1.108, 1.117, and 1.140, respectively. The reason for the increasing slope is that the traffic aggregation effect in the multi-fiber bundle scenario makes the LFB utilization higher, so that the traffic add / drop ratio is smaller, resulting in an increasing slope. Based on this trend, when a type of add / drop ratio is known, the other type of ratio can be quickly derived. For example, in the case of g = 1, the slope between the two types of add / drop ratios is approximately 0.393, which can be obtained from . Figure 6

[0053] For irregular network topologies, the traffic add / drop ratio can be generally expressed as: wherein and represent the total number of occupied working capacity units and protection capacity units, respectively, represents the total number of configured survivable services in the FSDM network. Therefore, characterizes the average number of capacity units occupied by each survivable service.

[0054] In the FSDM network, it is crucial to ensure the survivability of the network in the event of a failure, because a single link failure can simultaneously interrupt all the fibers in the same cable, thereby causing a serious impact on network traffic. However, research on service configuration based on shared backup path protection (SBPP) in multi-fiber optical networks with different spatial superchannel (Spa SCh) granularities is still relatively limited.

[0055] The core idea of the SBPP technology is that as long as the corresponding working paths do not share any links, their protection paths can share common protection capacity. In order to better understand the configuration of optical path services based on SBPP in FSDM networks containing OXCs with limited add / drop ports, a key concept of a spectrum slot bundle plane (FSBTP) is defined, which is a set of virtual links generated by replicating the network physical links, and each virtual link corresponds to one FSBT. If all the FSBTs of a link are busy, the link is removed from the FSBTP.

[0056] It is assumed that each link has w FSBTs, and each FSBT is composed of , ,..., ​F = g * (F - FSBTP) + FSBTP, where F is the number of fiber pairs, g is the granularity of Spa SCh. Then, for each FSBTP, it copies the links from the physical links of the network topology. Here, if all the FSBs in a FSBTP are in the "busy" state, a link is removed from the FSBTP. Figure 7 An example of setting up a pair of working and protection optical paths sharing a pair of transceivers or adding / deleting ports is provided. In order to achieve fast recovery, it is assumed that the two optical paths use the same center wavelength, so that wavelength adjustment is not required. The two optical paths are configured within a shared FSBTP (e.g., FSBTP1).

[0057] To solve the A / DPRFSA problem in the FSDM network based on the SBPP optical path, an adaptive routing algorithm based on the FSBTP is proposed to optimize the network blocking performance.

[0058] Further, based on the add / drop port threshold, the adaptive routing algorithm first determines whether there are idle add / drop ports at the source node and the destination node to start the search for the subsequent working path and protection path, thereby realizing the dynamic survival optical path configuration of the FSDM optical network based on shared backup path protection. The implementation steps are as follows: S31: Idle state detection is performed on the add / drop ports of the source node and the destination node respectively: if any node has no idle port, the current service request is terminated and marked as blocked; if there are idle ports at both nodes, a search counter k = 1 is initialized; S32: A candidate spectrum slot bundle plane set is generated according to the number of spectrum slot blocks required by the current service request and the network configuration parameters, the network physical topology links are copied, all spectrum slot bundle links marked as busy are removed, and if all spectrum slots of any link are in the busy state, the link is removed from the current spectrum slot bundle plane; S33: Based on the candidate spectrum slot bundle plane set, a working path from the source node to the destination node is searched in the Kth spectrum slot bundle plane using the Dijkstra algorithm: If the working path is found, step S34 is entered to perform the protection path search step; If not, the value of the search counter k is incremented by one, and step S35 is entered; S34: In the Kth spectrum slot bundle plane, spectrum slot bundle links that do not meet the capacity sharing rule of shared backup path protection are removed, and a protection path from the source node to the destination node is searched among the remaining spectrum slot bundle links using the Dijkstra algorithm: If the protection path is found, an idle spectrum slot block is selected on the spectrum slot block link corresponding to the working path and the protection path by using a plurality of selection strategies, and the state of the selected spectrum slot block is updated to busy, and then step S36 is entered; The plurality of selection strategies include, but are not limited to, a first-fit strategy, a least-load strategy and a random strategy; preferably, the random strategy is used in the embodiment to meet the assumption in the analytical model (FSB-AM model), that is, a candidate idle FSB is randomly selected for allocation; If not, the value of the search counter k is increased by one, and step S33 is returned to be executed; S35: whether k is less than or equal to the average number of spectrum slot block bundles of each link is judged: If yes, step S33 is returned; If no, it is determined that the current service request is blocked, and then step S36 is entered; S36: whether all service requests are completed for routing and resource allocation is checked: If yes, the network blocking probability is calculated ; If not, the next unprocessed service request is switched to, and step S31 is returned to be executed.

[0059] Further, in the embodiment, in S32, the method for generating the candidate spectrum slot block bundle plane set is as follows: S321: based on the physical link of the FSDM optical network, the connection relationship of all nodes and links is copied to obtain a spectrum slot block composed of all spectrum slot blocks on a group of virtual links, and all virtual links are grouped in sequence to form an initial spectrum slot block bundle plane; S322: according to the number of spectrum slot blocks required by the current service request, the state of all spectrum slot block bundles in the initial spectrum slot block bundle plane is detected: In the initial spectrum slot block bundle plane, all spectrum slot block bundles containing at least the number of idle spectrum slot blocks satisfying the current service request are retained, and all spectrum slot block bundles in which all spectrum slot blocks are occupied are removed, if all spectrum slot block bundles on any virtual link are removed, the link is removed from the corresponding spectrum slot block bundle plane, and a candidate spectrum slot block bundle plane set is obtained.

[0060] The experiment uses, for example Figure 8Two types of test network topologies are shown to verify the effectiveness of the technical solutions of the application, as follows: (a) a COST239 network, containing 11 nodes and 26 links; (b) a NSFNET network, containing 14 nodes and 21 links; each link in the two types of networks is configured with 6 optical fibers. The service-related parameters are set as follows: the number of spectrum slots required by the service is randomly generated in the range of 1 to 7, and a single optical fiber can provide 50 spectrum slot resources; the arrival process of the optical path service obeys a Poisson distribution with an arrival rate of λ (unit: times / sec), and the service holding time obeys a negative exponential distribution with a mean of 1 / σ, and the mean is normalized to 1.0, based on which, the service load between each pair of nodes is characterized by λ Erlang. The service load of each node in the network is uniformly distributed among the nodes, and the experiment simulation is performed for a total of 10 6 times of optical path arrival events; when the service arrives, if the working optical path or the protection optical path cannot be successfully established, the arrival event is determined to be a blocking event.

[0061] To verify the accuracy of the FSB-AM (frequency spectrum block allocation analysis model) proposed in the application, the calculation results thereof are compared with the simulation results based on the FSDM optical network combined with the uplink and downlink port threshold points. The physical meaning of the threshold points is that when the network blocking is mainly caused by the limited FSB capacity, increasing the additional uplink and downlink ports cannot bring significant blocking performance improvement.

[0062] In the experiment, the node pair service load of the COST239 network is set to 2 Erlang, and the node pair service load of the NSFNET network is set to 1 Erlang; the specific experimental process is as follows: gradually increase the number of uplink and downlink ports of each node until the blocking probability reaches a saturation point, and the saturation point is defined as the uplink and downlink port threshold point; at the saturation point, the blocking caused by the lack of idle uplink and downlink ports accounts for a negligible proportion in the total blocking probability.

[0063] In the case of and , the target parameters and need to be determined; to obtain the data lacking and , simulation data is relied on for verification. To obtain , it is assumed in the simulation experiment that each node has a different number of uplink and downlink ports. When processing the ith service arrival request, the uplink / downlink ratio of the current network is calculated. To obtain the LFB utilization rate , the average value of the FSB utilization rate of each LFB is taken during the entire simulation process.

[0064] Table 1 lists the threshold number of add / drop ports in the SBPP (Shared Backup Path Protection) mode, wherein the "theoretical value" is calculated by the FSB-AM model of the present application; by comparing the theoretical value with the simulation value, it can be seen that the calculation result of the analytic model is highly consistent with the simulation result, and can provide a lower limit reference for the number of add / drop ports of each optical cross-connect (OXC) device in the FSDM network; the threshold number has a key significance for the FSDM network, which represents the minimum number of add / drop ports that each OXC needs to be configured to avoid service blocking due to insufficient idle add / drop ports.

[0065] Table 1 Threshold point of add / drop port number

[0066]

[0067] To verify the efficiency of the adaptive routing algorithm based on FSBTP proposed in the present application, the performance of the A / DPRFSA (Adaptive / Dynamic Priority Routing Frequency Spectrum Allocation) algorithm is compared with that of the algorithm based on fixed routing; in the experiment, the number of add / drop ports of each OXC in the FSDM network is set to be based on the threshold value of each Spa SCh granularity; Figure 9 The variation trend of the optical path blocking probability of the COST239 network and the NSFNET network under different node pairs of service load and different Spa SCh granularity conditions is presented.

[0068] The experimental results show that the adaptive routing algorithm based on FSBTP is significantly superior to the algorithm based on fixed routing in terms of blocking probability performance; the core reason is that the adaptive routing algorithm adopts a joint processing mechanism of routing and frequency spectrum allocation, while the fixed routing algorithm only performs frequency spectrum allocation along the preset route, resulting in a reduced success rate of the protection optical path based on SBPP.

[0069] It can also be obtained from the experimental results that the performance of the adaptive routing algorithm under a smaller Spa SCh granularity is superior to that under a coarser Spa SCh granularity; the essential reason is that a smaller Spa SCh granularity can provide more optional LFBs in the A / DPRFSA process, thereby realizing more flexible network resource allocation.

[0070] In addition, it is worth noting that under the action of the adaptive routing algorithm based on FSBTP, the performance difference between Spa SCh granularity g=3 and g=1, g=2 is smaller than that between g=3 and g=6; therefore, from the perspective of cost-effectiveness, the medium-scale Spa SCh granularity is the optimal scheme for resource configuration in the FSDM network.

[0071] Based on the same inventive concept as the method, the present application also provides a FSDM network limited add / drop port dynamic survival optical path configuration system, like Figure 10As shown, the system comprises a network construction module 100, an analysis calculation module 200, and a resource configuration module 300. The network construction module 100 is configured to construct a FSDM optical network using a shared laser source and a local oscillator, wherein each link of the FSDM optical network comprises a link fiber bundle composed of multiple optical fibers, the link fiber bundle shares the laser source and the local oscillator, and an optical cross-connect node is configured with a limited number of add-drop ports. The analysis calculation module 200 is configured to establish a spectrum slot block-based analysis model, to predict the network blocking performance of different optical cross-connect nodes under the number of add-drop ports of the optical cross-connect nodes by using the analysis model, and to determine the add-drop port threshold of the optical cross-connect nodes. The resource configuration module 300 is configured to construct an adaptive routing algorithm based on a spectrum slot block bundle plane, to determine whether there are idle add-drop ports between a source node and a destination node by using the adaptive routing algorithm based on the add-drop port threshold, to start the search of subsequent working paths and protection paths, and to realize the dynamic survival path configuration of the FSDM optical network based on shared backup path protection.

[0072] Obviously, the above embodiments are only examples for clearly illustrating, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for configuring a survivable optical path of a limited add / drop port in an FSDM network, characterized in that, Comprise: S1: Constructing an FSDM optical network using a shared laser source and a local oscillator, each link in the FSDM optical network containing a link fiber bundle composed of multiple optical fibers, the link fiber bundle sharing the laser source and the local oscillator, and the optical cross-connect node being configured with a limited number of add-drop ports; S2: Establishing a spectral slot block-based analytical model to predict the network blocking performance of different optical cross-connect nodes under different numbers of add-drop ports, and determining the add-drop port threshold of the optical cross-connect node based on the analytical model; S3: Constructing an adaptive routing algorithm based on the spectral slot block bundle plane, and based on the add-drop port threshold, first determining whether there are idle add-drop ports between the source node and the destination node through the adaptive routing algorithm to start the search for the working path and the protection path, and realizing the dynamic survivable light path configuration of the FSDM optical network based on shared backup path protection.

2. The method of claim 1, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, In S1, the number of link fiber bundles satisfies: where F is the total number of fibers contained in each link of the FSDM optical network, g is the spatial super-channel granularity of the FSDM optical network, i.e., the total number of fibers contained in each link fiber bundle; and each fiber constituting a link fiber bundle contains o spectral slots, and the size of a spectral slot block formed by the link fiber bundle is g x o spectral slots.

3. The method of claim 1, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, In S2, the method for determining the add-drop port threshold of the optical cross-connect node is as follows: For the target optical cross-connect node, start with the minimum number of ports and gradually increase the number of add-drop ports. Each time the number of ports is increased, the total network blocking probability is recalculated through the analytical model; When the following two conditions are met, the current number of add-drop ports is the add-drop port threshold: Condition one: the total network blocking probability reaches the saturation point, that is, when the number of add-drop ports increases, the total network blocking probability no longer changes; Condition two: the total network blocking probability caused by insufficient add-drop ports is less than or equal to a preset threshold, at which point the blocking caused by insufficient add-drop ports accounts for a negligible proportion in the total network blocking probability, and the total network blocking probability is mainly caused by insufficient spectral slot block capacity.

4. The method of claim 3, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, In S2, the method for calculating the total network blocking probability is as follows: Calculating utilization of individual add / drop ports of any optical cross-connect node : ， wherein, is a link fiber bundle utilization, is a traffic up / down ratio, is a system up / down ratio; based on the utilization , a probability that all of the ports in the source node are occupied is , and a probability that all of the ports in the destination node are occupied is ; According to the described and the described , the probability of the total blocking of the network, i.e. the blocking probability due to the limited spectrum slot block capacity is obtained. wherein, is the spectral slot blocking probability on the link fiber bundle.

5. The method of claim 4, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, Spectrum slot blocking probability on the link fiber bundle The calculation method is as follows: Introducing a spare capacity sharing coefficient , for describing the sharing efficiency of the link fiber bundle, calculating the spectrum slot blocking probability on the link fiber bundle : ； wherein, is the link fiber bundle utilization, is the number of link fiber bundles, is the average number of spectral slot bundles per link, H is the average number of hops for the working or protection lightpath.

6. The method of claim 4, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, The method of calculating the system up / down ratio is as follows: The method of calculating the system up / down ratio is as follows: , is the number of uplink ports on the actual deployed system of the node, denotes the average node degree of the network, is the average number of spectral slot beams on each link, denotes the average total number of spectral slots incident on the node.

7. The method of claim 4, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, calculating the business ratio The method is as follows: , is the actual number of add / drop optical paths on the node, denotes the average node degree of the network, is the average number of spectral slot beams on each link, denotes the total number of spectral slots of the effective optical paths carried on all incident links of the node.

8. The method of claim 1, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, In S3, based on the add-drop port threshold, first determine whether there are idle add-drop ports between the source node and the destination node through the adaptive routing algorithm to start the search for the working path and the protection path, and realize the dynamic survivable light path configuration of the FSDM optical network based on shared backup path protection. The method is as follows: S31: Perform idle state detection on the add-drop ports of the source node and the destination node respectively: if either node has no idle port, terminate the current service request and mark it as blocked; if both nodes have idle ports, initialize the search counter k = 1; S32: Generate a candidate spectral slot block bundle plane set according to the number of spectral slot blocks required by the current service request and the network configuration parameters, copy the network physical topology link, and remove all spectral slot block bundle links marked as busy. If all spectral slot blocks of any link are in a busy state, the link is removed from the current spectral slot block bundle plane; S33: Based on the candidate spectral slot block bundle plane set, search for the working path from the source node to the destination node in the Kth spectral slot block bundle plane: If the working path is found, go to step S34 and perform the protection path search step; if not, increase the value of the search counter k by one and go to step S35; S34: In the Kth spectrum slot bundle plane, remove the spectrum slot bundle links that do not meet the shared backup path protection capacity sharing rule, and search for a protection path from the source node to the destination node among the remaining spectrum slot bundle links: If the protection path is found, select an idle spectrum slot on the spectrum slot bundle link corresponding to the working path and the protection path, update the state of the selected spectrum slot to busy, and then go to step S36; if not, increase the value of the search counter k by one and return to step S33; S35: Determine whether k is less than or equal to the average number of spectrum slot bundles per link: If yes, return to step S33; if no, determine that the current service request is blocked, and then go to step S36; S36: Check whether all service requests are completed for routing and resource allocation: If yes, calculate and calculate the network blocking probability; if not, switch to the next unprocessed service request and return to step S31.

9. The method of claim 8, wherein the FSDM network limited add-drop port dynamic survivable optical path configuration method is characterized by, In S32, the method for generating a candidate spectrum slot bundle plane set is as follows: S321: Based on the physical link of the FSDM optical network, copy the connection relationship of all nodes and links to obtain a spectrum slot bundle composed of all spectrum slot sets on a group of virtual links, and group all virtual links in sequence to form an initial spectrum slot bundle plane; S322: According to the number of spectrum slots required by the current service request, perform state detection on all spectrum slot bundles in the initial spectrum slot bundle plane: In the initial spectrum slot bundle plane, keep all spectrum slot bundles containing at least the number of idle spectrum slots required by the current service request, remove all spectrum slot bundles whose all spectrum slots are occupied, and if all spectrum slot bundles on any virtual link are removed, remove the link from the corresponding spectrum slot bundle plane to obtain a candidate spectrum slot bundle plane set.

10. A system for configuring a limited add / drop port dynamic survivability optical path in an FSDM network, characterized in that, Comprise: A network construction module for constructing an FSDM optical network using a shared laser source and a local oscillator, wherein each link in the FSDM optical network comprises a link fiber bundle composed of multiple optical fibers, the link fiber bundle shares the laser source and the local oscillator, and an optical cross-connect node is configured with a limited number of add-drop ports; An analysis calculation module for establishing a spectrum slot-based analysis model to predict the network blocking performance of different optical cross-connect nodes under different numbers of add-drop ports, and determining an add-drop port threshold of the optical cross-connect node; And a resource configuration module for constructing an adaptive routing algorithm based on a spectrum slot bundle plane, based on the add-drop port threshold, the adaptive routing algorithm is used to determine whether there is an idle add-drop port between the source node and the destination node to start the search of the subsequent working path and protection path, and realize the dynamic survival optical path configuration of the FSDM optical network based on shared backup path protection.

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