A proactive route maintenance method based on three-dimensional spatial local link failure estimation

Abstract

This invention discloses a proactive route maintenance method based on three-dimensional spatial local link failure estimation. This method utilizes a defined Minimum Keep-Connect Time (LHT) to filter out the segments of a multipath that most require link maintenance. Then, it comprehensively considers link similarity and path prediction validity to select the optimal backup route, reducing the granularity of backup paths to the link level. This minimizes the frequency of route discovery without reserving excessive link and bandwidth resources for backup paths, reducing the control information overhead and energy consumption caused by route re-establishment, and improving the lifespan of network nodes. Ultimately, it better meets the route maintenance requirements of integrated space-ground networks in military networks, featuring low additional energy and time consumption and long network node lifespan.

Description

Technical Field

[0001] This invention relates to the field of computer network technology, and more specifically to a proactive routing maintenance method based on three-dimensional spatial local link failure estimation. Background Technology

[0002] Mobile ad hoc networks are multi-hop, temporary, self-organizing network systems. Due to their flexibility and convenience in network deployment, they stand out among many network types and are widely used in the military field. Since tactical military networks mostly use wireless transmission mechanisms, their bandwidth limit is generally much lower than that of traditional wired networks. In order to improve network transmission efficiency, reduce latency, balance network load, and avoid congestion, multiple non-overlapping paths can be selected for load balancing, thereby meeting the throughput requirements of the service flow as much as possible.

[0003] However, due to the characteristics of military networks, network nodes can move freely and randomly. This may cause two nodes that originally had a direct wireless link to go beyond each other's signal coverage, leading to the disconnection of the wireless link and ultimately the interruption of the transmission path. If transmission is to continue in this situation, a new route can only be re-established through network-wide topology discovery and route calculation, which will inevitably cause additional energy consumption and time overhead. Therefore, minimizing the frequency of route discovery and improving the lifespan of network nodes through reasonable route maintenance algorithms has always been a very important part of the design of routing schemes for mobile ad hoc networks.

[0004] Traditional mobile ad hoc network models are almost planar, and link expiration time is often used to predict how long a directly connected wireless link can still provide service in a mobile ad hoc network; however, the topology of military networks may exhibit a certain three-dimensional spatiality due to the participation of aerial combat units such as drones in the network.

[0005] Therefore, it is urgent to research and design a new multi-path routing maintenance method that supports three-dimensional space to meet the routing maintenance requirements of integrated space-ground networks in military networks, and thereby reduce the additional energy consumption and time overhead of nodes recalculating routes. This has become an urgent problem to be solved in this field. Summary of the Invention

[0006] To address the aforementioned problems, this invention aims to provide a proactive route maintenance method based on three-dimensional spatial local link failure estimation. This method sets up backup paths for links in military service flow paths that are prone to disconnection due to node movement. It uses a defined minimum keep-alive time (LHT) to filter out the segments of the multi-path that most require link maintenance. Then, it comprehensively considers link similarity and path prediction validity to select the optimal backup route, reducing the granularity of backup paths to the link level. Thus, it minimizes the frequency of route discovery without reserving too many links and bandwidth resources for backup paths, reduces the control information overhead and energy consumption caused by route re-establishment, and improves the lifespan of network nodes. It features low additional energy consumption and time overhead, and long network node lifespan.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A proactive route maintenance method based on three-dimensional spatial local link failure estimation, including

[0009] Step 1: Update the bandwidth usage on the network topology graph G based on the multi-path transmission path set, remove links on graph G whose remaining bandwidth does not meet the conditions, and initialize the set of backup paths used to store each transmission path in the transmission path.

[0010] Step 2: In one path of multipath transmission, find the two nodes with the minimum keep-alive time (LHT);

[0011] Step 3: Using the two nodes from Step 2 as the source node and the destination node respectively, calculate the set of candidate backup links, and determine and select backup paths;

[0012] Step 4: Based on the path found in Step 3, determine whether the number of hops in the backup path set will be less than that of the original path after this path is stored in the backup path set.

[0013] Step 5: Update the network diagram G based on the bandwidth resource reservation for this path, and remove links in diagram G whose remaining bandwidth does not meet the conditions.

[0014] Step 6: Replace the part of the original path with the one containing the minimum LHT with this path to obtain a new transmission path, and then repeat steps 2 to 5.

[0015] Step 7: Repeat steps 3 through 6 until all primary paths have completed the maintenance of backup paths.

[0016] Preferably, the specific process of updating the bandwidth occupancy on the network topology graph G based on the multi-path transmission path set in step 1, removing links on graph G whose remaining bandwidth does not meet the conditions, and simultaneously initializing the set used to store the backup path set for each transmission path includes:

[0017] Step 1.1: In multipath routing of mobile ad hoc networks, let the throughput requirement be T. need The set of transmission paths for a service flow with source node S and destination node D is:

[0018] path M = [path1, ..., path k ];

[0019] Where k is the transmission path, 1≤k≤3;

[0020] Step 1.2: Based on the transmission path set path M The bandwidth occupancy of the undirected connected graph G(V,E) of the military network topology is updated, and graphs with remaining bandwidth less than a certain value are removed. The link;

[0021] Step 1.3: Initialize a path storage space M The set of backup paths for each transmission path. path This set is:

[0022] Backup path = [B_path1, ..., B_path k ].

[0023] Preferably, the specific process of finding the two nodes with the minimum hold-for-time (LHT) in one path of multipath transmission as described in step 2 includes:

[0024] Step 2.1: Let any path in the multipath transmission be path1 = [S, ..., node i The two nodes with the minimum keep-alive time (LHT) are (node ​​..., D] i node i+1 The information for each node i is: latitude, longitude, and altitude (x). i y i h i ), speed of motion, magnitude v i Direction of motion (θ) i1 θ i2 Assuming nodes i and j maintain their current speeds, their latitude, longitude, and altitude will change after LHT time as follows:

[0025]

[0026] The situation when nodes i and j move to the maximum communication distance r is as follows:

[0027]

[0028]

[0029]

[0030] A+B+C=r 2 ;

[0031] In the above formula, x is latitude, y is longitude, h is altitude, and θ is... i1 θ is the pitch angle, with a value range of [-π / 2, π / 2]; i2 The azimuth angle has a range of [0, 2π].

[0032] Step 2.2: Simplify the above expression by combining like terms, and we get:

[0033]

[0034] Let a = v i cosθ i1 cosθ i2 -v j cosθ j1 cosθ j2 c = v i cosθ i1 sinθ i2 -v j cosθ j1 sinθ j2 b = x i -x j d = y i -y j e = v i sinθ i1 -v j sinθ j1 f = h i -h j ,have to:

[0035]

[0036] The final LHT is:

[0037]

[0038] Preferably, step 3, which involves calculating the set of candidate backup links and determining the backup path, includes...

[0039] Step 3.1: Using node i For the source node, node i+1 For the destination node, calculate the candidate backup link set alt_backup_paths = [path′1, path′2, ...];

[0040] Step 3.2: If alt_backup_paths can be calculated, then select the highest priority path from the candidate path set. i , where: path′ i =[node i ,node′1,node′2,...,node i+1 ];

[0041] Otherwise, the destination node needs to be extended along path1 towards D until path′ can be found. i =[node i ,node′1,node′2,...,node j ]until.

[0042] Preferably, in the alternative path selection process described in step 3.2, the priority P of the alternative path is...

[0043]

[0044] Where L is the link similarity of the path pair, T is the estimated validity period of the path, and H is the number of hops of the path.

[0045] Preferably, step 4, which involves determining whether the hop count of the links in the backup path set is less than that of the original path, includes...

[0046] Determine if path' i After storing the alternative path set B_path1, will the link hop count in B_path1 be less than that in path1?

[0047] (1) If it is less than or equal to, then path′ i Store it in B_path1 as a backup path for path1, and continue to execute "Step 5";

[0048] (2) If it is greater than, it is necessary to continue to check whether B-path1 is empty. If it is empty, then path′ i Store the data in B_path1 before executing "Step 7"; otherwise, execute "Step 7" directly.

[0049] Preferably, the process of eliminating links whose remaining bandwidth does not meet the conditions in step 5 includes:

[0050] According to path′ i Regarding bandwidth resource reservation, the military network map G is updated, and maps with remaining bandwidth less than a certain value are removed from map G. The link.

[0051] Preferably, between steps 6 and 7, path1 in "step 2" needs to be replaced with path. M For other primary paths that have not completed backup path maintenance, repeat steps 3 through 6.

[0052] The beneficial effects of this invention are: This invention discloses a proactive route maintenance method based on three-dimensional spatial local link failure estimation. Compared with the prior art, the improvement of this invention lies in:

[0053] This invention proposes a proactive route maintenance method based on three-dimensional spatial local link failure estimation. This method is applicable to multi-path route maintenance in mobile ad hoc networks. In practice, it sets up backup paths for links in military service flow paths that are prone to disconnection due to node movement. It uses the defined minimum keep-alive time (LHT) to filter out the segments of the multi-path that most require link maintenance. Then, it comprehensively considers link similarity and path prediction validity period to select the optimal backup route, which can reduce the granularity of backup paths to the link level. Thus, it minimizes the frequency of route discovery as much as possible without reserving too many links and bandwidth resources for backup paths, reduces the control information overhead and energy consumption caused by route re-establishment, and improves the lifespan of network nodes. Ultimately, it can better meet the route maintenance needs of integrated space-ground networks in military networks, with the advantages of low additional energy consumption and time overhead and long network node lifespan. Attached Figure Description

[0054] Figure 1 This is a schematic diagram illustrating the working principle of the proactive route maintenance method based on three-dimensional spatial local link failure estimation of the present invention.

[0055] Figure 2 This is a flowchart of the algorithm for the proactive route maintenance method based on three-dimensional spatial local link failure estimation of the present invention.

[0056] Figure 3 This is a schematic diagram illustrating the path selection principle of the present invention.

[0057] Figure 4 This is a pseudocode diagram of the multi-path routing maintenance method of the present invention. Detailed Implementation

[0058] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0059] Example 1: Refer to Appendix Figure 1-4 The proposed route maintenance method based on three-dimensional spatial local link failure estimation is shown. Assume that the routing algorithm has already been used to determine the throughput requirement as T. need A military service flow with source node S and destination node D selects a multi-path transmission path, and its transmission path set is path. M = [path1, ..., path k According to the conclusion drawn by Peter P. Pham and Sylvie Perreau et al. through problem modeling and mathematical derivation on the number of paths, the overhead will increase significantly when there are more than 3 transmission paths in a mobile ad hoc network. Therefore, 1≤k≤3.

[0060] according to Figure 2 As shown, the core steps of the multi-path routing maintenance algorithm mainly include:

[0061] Step 1: In multipath routing for mobile ad hoc networks, let the throughput requirement be T. need The set of transmission paths for a service flow with source node S and destination node D is called path. M = [path1, ..., path k ], where k is the transmission path, 1≤k≤3; based on the transmission path set path M For the undirected connected graph G(V,E) of the military network topology.

[0062] Update the bandwidth usage status and remove graphs with less than [a certain amount of bandwidth remaining] in graph G. The link; at the same time

[0063] Initialize a path storage M The set of backup paths for each transmission path. path This set can be represented as:

[0064] Backup path = [B_path1, ..., B_path k ];

[0065] Step 2: In path1 = [S, ..., node i Find the two nodes in [D] that have the minimum LinkHolding Time (LHT). i node i+1 );

[0066] The link consists of nodes arranged in sequence. The LHT of adjacent nodes is calculated from beginning to end, and the two nodes with the smallest LHT are finally found.

[0067] Step 3: Using node i For the source node, node i+1 For the destination node, calculate the candidate backup link set alt_backup_paths = [path′1, path′2, ...];

[0068] If alt_backup_paths can be calculated, then select the highest priority path from the candidate path set. i , where: path′ i =[node i ,node′1,node′2,...,node i+1 ];

[0069] Otherwise, the destination node needs to be extended along path1 towards D until path′ can be found. i =[node i ,node′1,node′2,….,node j ]until;

[0070] Step 4: Determine if path' will be... i After storing the backup path set B_path1, check whether the number of hops in B_path1 is less than that in path1 (the criterion is the number of hops in the link; if the backup path is "shorter" than the original path (smaller number of hops), then accept this path as the backup path). The main purpose is to check whether the resources reserved by the maintained backup link are greater than those of the original transmission path after adding this backup link.

[0071] If it is less than or equal to, then path' i Store it in B_path1 as a backup path for path1, and continue to execute "Step 5";

[0072] If it is greater than, it is necessary to further check whether B_path1 is empty. If it is empty, then path' i Store the data in B_path1 before proceeding to "Step 7"; otherwise, proceed directly to "Step 7".

[0073] Step 5: Based on path′ i Regarding bandwidth resource reservation, the military network map G is updated, and maps with remaining bandwidth less than a certain value are removed from map G. The link;

[0074] Among them, "update" refers to subtracting the reserved and allocated bandwidth from the original bandwidth to give the final remaining bandwidth;

[0075] Step 6: Use path' iReplace node in path1 i To node j In this part, we get the new path1, and then repeat "step 2" to "step 5";

[0076] Step 7: Replace path1 in "Step 2" with path M For other primary paths that have not completed backup path maintenance, repeat steps 3 through 6 until all primary paths have completed backup path maintenance.

[0077] Preferably, the calculation process for the connection duration (LHT) in step 2 includes, among other things, the following:

[0078] Step 2.1: The signal coverage strength of the terminal device will gradually weaken as the transmission interval distance increases, until the connection is disconnected after reaching the maximum transmission interval distance r; that is, as long as the transmission distance between any two network nodes is not greater than r, a wireless connection can be maintained and normal communication can be carried out; treating the Earth as a uniform sphere with a radius R = 6371.0088 km, each node can obtain its position and motion information through a positioning system combined with inertial navigation devices and barometric altimeters; the information that each node i can obtain includes: latitude and longitude and altitude information (x i y i h i (x is latitude, y is longitude, h is altitude), magnitude of the speed of motion v i Direction of motion (θ) i1 θ i2 )(θ i1 θ is the pitch angle, with a value range of [-π / 2, π / 2]; i2 (The azimuth angle ranges from [0, 2π]); for example, if two nodes i and j maintain their current speed, their latitude, longitude, and altitude will change after LHT time as follows:

[0079]

[0080] R is the Earth's radius, and r is the maximum transmission interval between the two nodes;

[0081] The situation when nodes i and j move to the maximum communication distance r can be expressed by the following formula:

[0082]

[0083]

[0084]

[0085] A+B+C=r 2

[0086] Step 2.2: By simplifying the above expression by combining like terms, we can obtain:

[0087]

[0088] Let a = v i cosθ i1 cosθ i2 -v j cosθ j1 cosθ j2 c = v i cosθ i1 sinθ i2 -v j cosθ j1 sinθ j2 b = x i -x j d = y i -y j e = v i sinθ i1 -v j sin0 j1 f = h i -h j We can obtain:

[0089]

[0090] The final LHT formula is:

[0091]

[0092] Preferably, the process of calculating the candidate backup link set in step 3 includes:

[0093] Step 3.1: Calculate the set of candidate backup links

[0094] The smaller the LHT between two nodes on the transmission path, the shorter the time the link remains connected, and the more necessary it is to maintain a backup path. It should be noted that the backup path here is not a backup from the source node to the destination node, but a backup between the nodes at both ends of the link with the smaller LHT. It only takes effect when the wireless link between these two nodes is lost due to relative movement between the two nodes. Of course, in some situations where link resources are scarce or in systems with a sparse number of nodes, such a backup path may not be found. In this case, it is only necessary to extend the node towards the destination. See the example section in the next section for a detailed explanation.

[0095] (2) How to select the best alternative path

[0096] Alternate path selection is used to choose the optimal alternative path when multiple alternative paths are available; specific operations are explained in the examples section below; before performing alternative path selection evaluation, the relevant concepts need to be defined:

[0097] Definition 1: Primary and backup path pair (path) M ,path′ i ), where path M =(V M E M V represents the set of transmission paths from source node S to destination node D planned by the routing algorithm for military traffic flows. M and E M These represent the nodes and links contained in the path set, respectively, path′. i =(V i E i ) represents a backup path, V i and E i These are the nodes and links included in the alternative path, respectively.

[0098] Definition 2: The link similarity L of a path pair is defined as follows: for a given primary / backup path pair (path... M ,path′ i For each link, the link similarity L is the set of links E it contains. M and E i The number of duplicate links in the path set, that is, the number of main paths in the path set. M and a certain alternative path 'path' i For each shared public link, the link similarity L increases by 1; the specific formula for calculating similarity L is as follows:

[0099]

[0100] in, n is the path M Medium path length;

[0101] Definition 3: The estimated validity period T of a path, for an alternative path path′ i In other words, the link set E can be obtained. i The LHT of each link included is calculated, and the smallest LHT value is taken as the estimated lifetime T(path′) of the backup path. i The estimated validity period is calculated using the following formula:

[0102] T(path′ i )=min(LHT(E i ))

[0103] Among them, E ifor path′ i The links included in the path.

[0104] Definition 4: The hop count H of a path, for an alternative path path′ i In terms of hop count H(path′) i This represents the number of links included in the backup path.

[0105] In selecting backup paths, in addition to ensuring good disjointness to increase fault tolerance and reduce channel contention, it is also necessary to maintain normal connectivity for as long as possible, thereby minimizing latency and overhead during route recovery and improving node lifetime. Furthermore, due to bandwidth constraints, a corresponding amount of bandwidth resources will be reserved on backup paths to ensure that the primary path can maintain the expected throughput when switching to backup paths. Therefore, the selection of backup paths also needs to ensure that their hop count is as small as possible, thereby reducing the reservation of bandwidth and link resources.

[0106] In summary, the selection of backup paths should be a value that is inversely proportional to the number of hops and link similarity, and directly proportional to the estimated validity period. Taking all three factors into account, backup paths should ultimately be prioritized.

[0107] Level P is set as In other words, the higher the priority of a candidate backup path, the more likely that path should be maintained as a backup path.

[0108] Example 2: Unlike Example 1, to verify the effectiveness of the proactive multipath routing maintenance method based on three-dimensional spatial local link failure estimation described in Example 1, a specific example is designed in this example to verify the above maintenance method:

[0109] like Figure 3 In the network system shown in (a), node S transmits service traffic to node D through the path [S, 1, 2, 4, D]. It is calculated that the LHT of the link (1, 2) between node 1 and node 2 is the smallest in the entire link. If at this time there is no alternative path from node 1 to node 2 that does not contain any links on the main path, it is only necessary to extend node 2 along the transmission path [S, 1, 2, 4, D] to the destination node D and node 4, and select the path [1, 3, 4] as the alternative path for link (1, 2). In this way, when node 1 detects a wireless link disconnection with node 2, it can start the alternative path by forwarding the data packet to node 3. At this time, the transmission path is switched to [S, 1, 3, 4, D], bypassing the disconnected link.

[0110] like Figure 3In the network shown in (b), node S will transmit service traffic to node D through the path [S, 1, 4, D]. It is calculated that the LHT of the direct link (1, 4) between node 1 and node 4 is the smallest in the entire path. In addition to the path [1, 2, 4], the backup path that can be used as link (1, 4) is [1, 3, 4]. At this time, the priority of the backup path selection needs to be used. The path with the highest priority is selected from the paths [1, 2, 4] and [1, 3, 4] as the backup path for link (1, 4).

[0111] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A proactive route maintenance method based on three-dimensional spatial local link failure estimation, characterized in that: include Step 1: Update the bandwidth usage on the network topology graph G based on the multi-path transmission path set, remove links on graph G whose remaining bandwidth does not meet the conditions, and initialize the set of backup paths used to store each transmission path in the transmission path. Step 2: In one path of multipath transmission, find the two nodes with the minimum keep-alive time (LHT); Step 3: Using the two nodes from Step 2 as the source node and the destination node respectively, calculate the set of candidate backup links, and determine and select backup paths; Step 4: Based on the path found in Step 3, determine whether the number of hops in the backup path set will be less than that of the original path after this path is stored in the backup path set. Step 5: Update the network diagram G based on the bandwidth resource reservation for this path, and remove links in diagram G whose remaining bandwidth does not meet the conditions. Step 6: Replace the part of the original path with the one containing the minimum LHT with this path to obtain a new transmission path, and then repeat steps 2 through 5. Step 7: Repeat steps 3 through 6 until all primary paths have completed the maintenance of backup paths.

2. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Step 1, which involves updating the bandwidth occupancy on the network topology graph G based on the multi-path transmission path set, removing links on graph G whose remaining bandwidth does not meet the conditions, and simultaneously initializing the set used to store the backup path set for each transmission path, includes the following specific processes: Step 1.1: In multipath routing of mobile ad hoc networks, let the throughput requirement be T. need The set of transmission paths for a service flow with source node S and destination node D is: path M =[path1,…,path k ]; Where k is the transmission path, 1≤k≤3; Step 1.2: Based on the transmission path set path M The bandwidth occupancy of the undirected connected graph G(V,E) of the military network topology is updated, and graphs with remaining bandwidth less than a certain value are removed. The link; Step 1.3: Initialize a path storage space M The set of backup paths for each transmission path. path This set is: Backup path =[B_path1,…,B_path k ]。 3. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Step 2 describes the specific process of finding the two nodes with the minimum keep-alive time (LHT) in a path of multipath transmission. Step 2.1: Let any path in the multipath transmission be path1 = [S,…,node] i [,…,D], the two nodes with the minimum keep-alive time LHT are (node i ,node i+1 The information for each node i is: latitude, longitude, and altitude (x). i ,y i ,h i ), speed of motion, magnitude v i Direction of motion (θ) i1 ,θ i2 Assuming nodes i and j maintain their current speeds, their latitude, longitude, and altitude will change after LHT time as follows: The situation when nodes i and j move to the maximum communication distance r is as follows: A+B+C=r 2 ; In the above formula, x is latitude, y is longitude, h is altitude, and θ is... i1 θ is the pitch angle, with a value range of [-π / 2, π / 2]; i2 The azimuth angle has a range of [0, 2π]. Step 2.2: Simplify the above expression by combining like terms, and we get: Let a = v i cosθ i1 cosθ i2 -v j cosθ j1 cosθ j2 、 c = v i cosθ i1 sinθ i2 -v j cosθ j1 sinθ j2 and b = x i -x j and d = y i -y j and e = v i sinθ i1 -v j sinθ j1 and f = h i -h j we get: The final LHT is:

4. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Step 3, which involves calculating the set of candidate backup links and determining the backup path, includes... Step 3.1: Using node i For the source node, node i+1 For the destination node, calculate the candidate backup link set alt_backup_paths = [path'1,path'2,...]; Step 3.2: If alt_backup_paths can be calculated, then select the highest priority path from the candidate path set. i , where: path' i =[node i ,node′1,node′2,…,node′ i+1 ]; Otherwise, the destination node needs to be extended along path1 towards D until path' can be found. i =[node i ,node'1,node'2,…,node j ]until.

5. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 4, characterized in that: In the alternative path selection process described in step 3.2, the priority P of the alternative path is... Where L is the link similarity of the path pair, T is the estimated validity period of the path, and H is the number of hops of the path.

6. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Step 4, which describes the process of determining whether the hop count of the links in the backup path set is less than that of the original path, includes... Determine if path' i After storing the alternative path set B_path1, will the link hop count in B_path1 be less than that in path1? (1) If it is less than or equal to, then path' i Store it in B_path1 as a backup path for path1, and continue to "Step 5"; (2) If it is greater than, it is necessary to continue to check whether B_path1 is empty. If it is empty, then path' i Store the data in B_path1 before executing "Step 7"; otherwise, execute "Step 7" directly.

7. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Step 5 describes the process of eliminating links whose remaining bandwidth does not meet the conditions, including... According to path i Regarding bandwidth resource reservation, the military network map G is updated, and maps with remaining bandwidth less than a certain value are removed from map G. The link.

8. The proactive route maintenance method based on three-dimensional spatial local link failure estimation according to claim 1, characterized in that: Between steps 6 and 7, you need to replace "path1" in "step 2" with "path". M For other primary paths that have not completed backup path maintenance, repeat steps 3 through 6.

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