Two-stage depth-first search routing calculation method for narrowband communication network

Abstract

The invention discloses a two-stage depth-first search routing calculation method for a narrowband communication network, and belongs to the technical field of computer communication. When a traditional narrowband routing method is used for processing a narrowband communication network topology of heterogeneous communication means hybrid networking, the problems that hello mechanism routing protocols are difficult to interact and a single communication means is difficult to decouple from a parallel link exist. By combining parallel links, constructing an adjacent matrix between nodes, equivalently mapping a communication link to a virtual node, and executing two-stage depth-first search, the method and the device provided by the invention can be used for realizing high-speed protocol information interaction under the condition of periodic protocol information interaction independent of a hello mechanism. And the routing calculation requirement of decoupling a single communication means from a composite means in a multi-graph topology scene is effectively met.

Description

Technical Field

[0001] The invention relates to the field of computer communications, and in particular to a two-stage depth-first search routing calculation method for a narrowband communication network. Background Art

[0002] In modern communication networks, routing algorithms are key technologies to ensure that data packets are transmitted smoothly from source nodes to destination nodes. However, in narrowband communication networks with limited bandwidth, traditional routing algorithms face many challenges.

[0003] First, in order to improve the adaptability and reliability of communication networks in different environments, heterogeneous communication means such as shortwave, low-speed satellites and meteor trails are usually used in narrowband communication networks to allow multiple different types of communication links to exist in parallel between neighboring communication nodes, that is, the network topology is a multi-graph structure. However, it is difficult for existing routing algorithms to decouple a single communication means from parallel links, resulting in routing calculation results that only support the use of composite communication means, which not only reduces the flexibility of routing selection, but also makes it difficult to meet the needs of specific communication tasks.

[0004] Secondly, routing algorithms in narrowband communication networks need to adapt to changes in network structure, but due to bandwidth limitations, traditional routing algorithms based on the hello mechanism are particularly difficult to implement in narrowband communication networks. The hello mechanism relies on periodic link state broadcasts to discover and maintain network topology information, but in narrowband networks, on the one hand, the high latency of the network makes it difficult for routing protocols to converge, and on the other hand, frequent protocol information exchanges occupy precious bandwidth resources, affecting user service communications in the network.

[0005] In the prior art CN117955891A, a time-deterministic multi-path routing selection method based on a random time-varying graph is disclosed. This method simulates the uncertainty and variability of the network state by constructing a random time-varying graph for the structural changes of the network topology, and calculates the shortest path using a load-balancing breadth-first search algorithm. However, this method only supports end-to-end multi-path routing calculations, and cannot meet the routing calculation requirements of decoupling a single communication means from a composite means in a multi-graph topology scenario.

[0006] In the prior art CN102118299A, an adaptive dynamic routing method is disclosed, which aims to solve the problems of limited bandwidth, complex channel conditions and uneven data flow in dedicated networks. In this method, a distance vector routing selection algorithm is used for narrowband routing and a link state routing selection algorithm is used for broadband routing. The routing information table is integrated and diffused in an iterative manner to converge and calculate the routing table of the entire network. However, the convergence process of this routing algorithm is highly dependent on information diffusion, which will cause a significant communication burden in a narrowband communication network networked by shortwave, low-speed satellites and meteor trails.

[0007] Therefore, it is necessary to provide a new technical solution to improve one or more problems existing in the above solutions. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a two-stage depth-first search routing calculation method for a narrowband communication network, aiming to help solve the problems existing in static routing calculation before the opening of a narrowband communication network.

[0009] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0010] A two-stage depth-first search routing calculation method for a narrowband communication network comprises the following steps:

[0011] Step (1), encoding the narrowband communication network topology into a structured data format, respectively describing the nodes and links in the narrowband communication network; using nodes to represent network communication controllers in the narrowband communication network topology, and using links to represent narrowband communication means, wherein the narrowband communication means include shortwave, low-speed satellites, and meteor trails;

[0012] Step (2), in the narrowband communication network, traverse all nodes and links in the network, and when there are multiple parallel communication links between each pair of neighboring nodes, merge the multiple parallel communication links between the nodes and regard them as one equivalent link;

[0013] Step (3), generating an inter-node adjacency matrix Π according to the topological connection relationship of the narrowband communication network;

[0014] Step (4), perform a first-stage depth-first search based on the node adjacency matrix Π to calculate all reachable paths between each pair of nodes;

[0015] Step (5), for all reachable paths between each pair of nodes, the actual communication link between neighboring nodes is equivalent to a virtual relay node, and the node adjacency matrix Ω of the virtual topology is generated;

[0016] Step (6), according to the node adjacency matrix Ω of the virtual topology, for the routing between each pair of nodes, a second-stage depth-first search is performed to calculate all reachable paths between each pair of nodes of the virtual topology;

[0017] Step (7), for all reachable paths of the virtual topology, the virtual nodes are mapped back to the actual communication links to form a narrowband static routing table.

[0018] Furthermore, in step (1), the narrowband communication network topology is encoded into a structured data format to describe the nodes and links in the narrowband communication network respectively, which specifically includes the following processes:

[0019] For the narrowband communication network topology, the node information is encoded into a structured data format, and each data includes a node ID, a node name, and a node type; the link information is encoded into a structured data format, and each data includes a link ID, a link name, a link type, a link head node ID, a link end node ID, and a link rate.

[0020] Furthermore, step (3) specifically includes the following steps:

[0021] Step (3.1), according to the topological connection relationship of the narrowband communication network, traverse all nodes and links in the network, record the connection status between each pair of nodes, and determine the connection relationship between each node;

[0022] Step (3.2) saves the connection relationship between nodes into a two-dimensional array of node adjacency matrix Π, where each element represents the connection relationship between the corresponding nodes, that is, if there is a link connection between any node i and node j, then Π [i][j] =1, otherwise Π [i][j] =0.

[0023] Furthermore, step (4) specifically includes the following steps:

[0024] Step (4.1), according to the node adjacency matrix Π constructed in step (3), initialize the relevant parameters of the depth-first search algorithm, including the starting node, the target node and the access mark;

[0025] Step (4.2), starting from the starting node, uses the depth-first search algorithm to traverse the narrowband communication network topology structure and calculates all reachable paths from each node to other nodes in the topology.

[0026] Furthermore, step (5) specifically includes the following steps:

[0027] Step (5.1), according to all reachable paths calculated in step (4), the actual communication link between neighbor communication nodes in the path is equivalent to a virtual relay node, and the mapping relationship between the actual communication link and the virtual relay node is saved in the mapping table M;

[0028] In step (5.2), the virtual relay nodes in the reachable path are combined with the actual communication nodes to form a virtual topology, and then the node adjacency matrix Ω of the virtual topology is constructed.

[0029] Furthermore, step (6) specifically includes the following steps:

[0030] Step (6.1) initializes the relevant parameters of the depth-first search algorithm, including the start node, the target node and the access mark, according to the node adjacency matrix Ω of the virtual topology constructed in step (5);

[0031] Step (6.2) starts from the starting node and uses a depth-first search algorithm to traverse the network structure of the virtual topology and calculate all reachable routes from the starting node to the target node in the virtual topology.

[0032] Furthermore, step (7) specifically includes the following steps:

[0033] Step (7.1) According to all reachable routes of the virtual topology obtained in step (6), the mapping table M is consulted, and the virtual relay node is mapped back to the actual communication link to obtain a routing information table containing nodes and links;

[0034] Step (7.2) encodes the routing information table into a structured data format and saves it to a file. Each piece of data includes the routing head node ID, routing end node ID, total hop count, each hop and link information of the routing.

[0035] The advantages of the present invention compared to the background technology are:

[0036] 1. Improvement of link bandwidth utilization: Compared with traditional routing algorithms, the narrowband communication network routing calculation method based on the two-stage depth-first search algorithm provided by the present invention does not rely on periodic messages similar to the hello mechanism in its calculation process, thereby reducing the communication burden and improving the actual utilization efficiency of the bandwidth.

[0037] 2. Accurate routing for networking with heterogeneous communication means: The narrowband communication network routing calculation method based on a two-stage depth-first search algorithm provided by the present invention is specially designed for communication networks that use a variety of heterogeneous communication means. By clearly distinguishing these communication means in the routing calculation, it is ensured that the routing selection can accurately reflect the communication means actually used.

[0038] 3. Efficiency of routing algorithm: The present invention provides a narrowband communication network routing calculation method based on a two-stage depth-first search algorithm. The core algorithm is a depth-first search algorithm. Compared with the breadth-first search algorithm or the shortest path search algorithm in the background technology, this algorithm is particularly suitable for narrowband communication network topology structures with multi-level hierarchical relationships. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a flow chart of a two-stage depth-first search routing calculation method for a narrowband communication network of the present invention.

[0040] Figure 2 It is a schematic diagram of network topology connection according to an embodiment of the present invention.

[0041] Figure 3 It is a schematic diagram of a network topology node adjacency matrix according to an embodiment of the present invention.

[0042] Figure 4 It is a result schematic diagram of a partial routing table obtained by the routing algorithm of an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0044] Refer to the instruction manual Figure 1 , Figure 1 The present invention is a flowchart of a two-stage depth-first search routing calculation method for a narrowband communication network; the method comprises the following steps:

[0045] Step 1: Encode the narrowband communication network topology into a structured data format, describing the nodes and links in the communication network respectively; use nodes to represent the network communication controller in the narrowband communication network, and use links to represent narrowband communication means such as shortwave, low-speed satellites and meteor trails. The typical network topology structure used in this embodiment refers to the attached manual. Figure 2 .

[0046] Step 1 specifically includes:

[0047] For the narrowband communication network topology, the node information is encoded into a structured data format, and each piece of data must include basic information such as node ID, node name, and node type; the link information is encoded into a structured data format, and each piece of data must include basic information such as link ID, node name, link type, link head node ID, link end node ID, link rate, etc.

[0048] Step 2: In a narrowband communication network, multiple parallel links are allowed to exist between neighboring nodes at the same time. Multiple communication links between nodes are merged and regarded as one equivalent link.

[0049] Step 2 specifically includes:

[0050] Step 2.1, for the narrowband communication network topology, supports reading the topology in which multiple parallel links exist between neighboring nodes at the same time, that is, the network topology is a multigraph;

[0051] In step 2.2, multiple communication links that exist simultaneously between each pair of neighbor nodes are merged into one equivalent link. At this time, the network topology is transformed into a simple graph.

[0052] Step 3: Generate the node adjacency matrix Π according to the topological connection relationship of the narrowband communication network.

[0053] Step 3 includes the following sub-steps:

[0054] Step 3.1, according to the topological connection relationship of the narrowband communication network, traverse all nodes and links in the network, record the connection status between each pair of nodes, and determine the connection relationship between each node;

[0055] Step 3.2: Based on the result of step 3.1, the connection relationship between each node is saved into the adjacency matrix Π in the form of a two-dimensional array, where each element represents the connection relationship between the corresponding nodes, that is, if there is a link connection between node i and node j, then Π [i][j] =1, otherwise Π [i][j] = 0. For the typical network topology structure adopted in this embodiment, the node adjacency matrix Π generated can refer to the attached specification. Figure 3 .

[0056] Step 4: According to the node adjacency matrix Π, perform the first stage depth-first search to calculate all reachable paths between each pair of nodes.

[0057] Step 4 specifically includes the following steps:

[0058] Step 4.1, according to the node adjacency matrix Π constructed in step 3, initialize the relevant parameters of the depth-first search algorithm, including the starting node, the target node and the access mark;

[0059] Step 4.2, starting from the starting node, use the depth-first search algorithm to traverse the narrowband communication network topology structure and calculate all reachable paths from each node to other nodes in the topology.

[0060] Step 5: For all reachable paths between each pair of nodes, the actual communication link between neighboring nodes is equivalent to a virtual relay node to generate the node adjacency matrix Ω of the virtual topology.

[0061] Step 5 specifically includes the following steps:

[0062] Step 5.1, according to all reachable paths calculated in step 4, the actual communication link between neighbor communication nodes in the path is equivalent to a virtual relay node, and the mapping relationship between the actual communication link and the virtual relay node is saved in the mapping table M;

[0063] In step 5.2, the virtual relay nodes in the reachable path are combined with the actual communication nodes to form a virtual topology, and then the node adjacency matrix Ω of the virtual topology is constructed.

[0064] Step 6: According to the node adjacency matrix Ω of the virtual topology, perform the second-stage depth-first search for the routing between each pair of nodes to calculate all reachable paths between each pair of nodes in the virtual topology.

[0065] Step 6 specifically includes the following steps:

[0066] Step 6.1, according to the node adjacency matrix Ω of the virtual topology constructed in step 5, initialize the relevant parameters of the depth-first search algorithm, including the starting node, the target node and the access mark;

[0067] Step 6.2, starting from the starting node, use the depth-first search algorithm to traverse the network structure of the virtual topology and calculate all reachable routes from the starting node to the target node in the virtual topology.

[0068] Step 7: For all reachable paths in the virtual topology, map the virtual nodes back to the actual communication links to form a narrowband static routing table.

[0069] Step 7 includes the following sub-steps:

[0070] Step 7.1, according to all reachable routes of the virtual topology obtained in step 6, refer to the mapping table M, map the virtual relay node back to the actual communication link, and obtain a routing information table containing nodes and links;

[0071] Step 7.2, encode the routing information table into a structured data format and save it to a file, where each piece of data includes information such as the routing head node ID, routing end node ID, total hop count, each hop and link passed by the route, etc.

[0072] For the typical network topology structure adopted in this embodiment, the generated partial routing table between node A and node E can refer to the attached manual. Figure 4 ,It can be verified from the figure that the algorithm proposed in the present invention can effectively meet the routing calculation requirements of decoupling a single communication means from a composite means in a multi-graph topology scenario without relying on the periodic protocol information interaction of the hello mechanism.

[0073] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A two-stage depth-first search routing calculation method for a narrowband communication network, characterized in that: The following steps are involved: Step 1, encoding the narrowband communication network topology into a structured data format, describing the nodes and links in the narrowband communication network respectively; using nodes to represent network communication controllers in the narrowband communication network topology, and using links to represent narrowband communication means, and the narrowband communication means include shortwave, low-speed satellites, and meteor trails; Step 2: In a narrowband communication network, traverse all nodes and links in the network, and when there are multiple parallel communication links between each pair of neighboring nodes, merge the multiple parallel communication links between the nodes and regard them as one equivalent link; Step 3, generating an inter-node adjacency matrix Π according to the topological connection relationship of the narrowband communication network; Step 4: Perform a first-stage depth-first search based on the node adjacency matrix Π to calculate all reachable paths between each pair of nodes. Step 5: For all reachable paths between each pair of nodes, the actual communication link between neighboring nodes is equivalent to a virtual relay node, and the node adjacency matrix Ω of the virtual topology is generated; Step 6: According to the node adjacency matrix Ω of the virtual topology, a second-stage depth-first search is performed for the routing between each pair of nodes to calculate all reachable paths between each pair of nodes of the virtual topology; Step 7: For all reachable paths of the virtual topology, the virtual nodes are mapped back to the actual communication links to form a narrowband static routing table.

2. A two-stage depth-first search routing calculation method for a narrowband communication network according to claim 1, characterized in that: In step 1, the narrowband communication network topology is encoded into a structured data format, which describes the nodes and links in the narrowband communication network respectively. The process includes: For the narrowband communication network topology, the node information is encoded into a structured data format, and each data includes a node ID, a node name, and a node type; the link information is encoded into a structured data format, and each data includes a link ID, a link name, a link type, a link head node ID, a link end node ID, and a link rate.

3. A two-stage depth-first search routing calculation method for a narrowband communication network according to claim 1, characterized in that: Step 3 specifically includes the following steps: Step 3.1, according to the topological connection relationship of the narrowband communication network, traverse all nodes and links in the network, record the connection status between each pair of nodes, and determine the connection relationship between each node; Step 3.2: Save the connection relationship between each node into the node adjacency matrix Π in the form of a two-dimensional array, where each element represents the connection relationship between the corresponding nodes, that is, if there is a link connection between any node i and node j, then Π [i][j] =1, otherwise Π [i][j] =0.

4. The two-stage depth-first search routing calculation method for a narrowband communication network according to claim 1, characterized in that: Step 4 specifically includes the following steps: Step 4.1, according to the node adjacency matrix Π constructed in step 3, initialize the relevant parameters of the depth-first search algorithm, including the starting node, the target node and the access mark; Step 4.2, starting from the starting node, use the depth-first search algorithm to traverse the narrowband communication network topology structure and calculate all reachable paths from each node to other nodes in the topology.

5. The two-stage depth-first search routing calculation method for a narrowband communication network according to claim 1, characterized in that: Step 5 specifically includes the following steps: Step 5.1, according to all reachable paths calculated in step 4, the actual communication link between neighbor communication nodes in the path is equivalent to a virtual relay node, and the mapping relationship between the actual communication link and the virtual relay node is saved in the mapping table M; In step 5.2, the virtual relay nodes in the reachable path are combined with the actual communication nodes to form a virtual topology, and then the node adjacency matrix Ω of the virtual topology is constructed.

6. A two-stage depth-first search routing calculation method for a narrowband communication network according to claim 1, characterized in that: Step 6 specifically includes the following steps: Step 6.1, according to the node adjacency matrix Ω of the virtual topology constructed in step 5, initialize the relevant parameters of the depth-first search algorithm, including the starting node, the target node and the access mark; Step 6.2, starting from the starting node, use the depth-first search algorithm to traverse the network structure of the virtual topology and calculate all reachable routes from the starting node to the target node in the virtual topology.

7. A two-stage depth-first search routing calculation method for a narrowband communication network according to claim 5, characterized in that: Step 7 specifically includes the following steps: Step 7.1, according to all reachable routes of the virtual topology obtained in step 6, refer to the mapping table M, map the virtual relay node back to the actual communication link, and obtain a routing information table containing nodes and links; Step 7.2, encode the routing information table into a structured data format and save it to a file, where each piece of data includes the routing head node ID, routing end node ID, total hop count, each hop and link information of the routing.

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