Message transmission method fusing priori routing and dtn and storage medium

Abstract

The application particularly relates to a message transmission method combining a priori routing and a DTN and a storage medium. The method comprises the following steps: establishing and maintaining a routing table in each node of the network based on a priori MANET routing protocol mechanism; when a message source node transmits a message to a message destination node: firstly, the message is transmitted by using the priori MANET routing mechanism; otherwise, a message copy distribution algorithm based on location information is used, and a DTN mechanism is used to distribute the message copy to a relay node at the topological boundary of the message source node end, so that the relay node becomes a virtual source node; if the message transmission is unsuccessful, the message copy is stored in the relay node at the interruption, so that the relay node becomes a virtual source node; the virtual source node broadcasts routing query information to its neighbor nodes, and the routing table of the neighbor nodes is inquired; when an opportunity to establish a connection with the message destination node is found, the above steps are repeated. The application can improve the reliability of message transmission by using the DTN routing mechanism, and can fully explore the connectable sub-topology in the MANET network.

Description

Technical Field

[0001] This invention relates to the field of wireless network protocol technology, specifically to a message transmission method and storage medium that integrates prior routing and DTN. Background Technology

[0002] Proactive routing, also known as active routing or table-driven routing, is specifically designed for MANET (Mobile Ad Hoc Network) environments. The main characteristic of proactive routing is that each node in the network maintains a stable routing table showing routes to other nodes. When the network topology changes, nodes can promptly obtain the change information and update their own routing tables. Each node knows the routes to all other nodes, so when a source node needs to send a message, it can immediately obtain the route to the message's destination node.

[0003] In existing technologies, message transmission methods based on priori MANET routing protocols are prone to network connectivity issues. This means that the corresponding routing information may become invalid, and the subsequent link may be broken when the message arrives at the routing relay node, preventing the message or message copy from being effectively transmitted to the destination node. To address this problem, existing technologies typically employ a fusion of multiple routing protocols. Specifically, when the priori MANET routing connection is lost, a serial switching mechanism is used to switch to another routing strategy to complete message transmission. However, while existing multi-routing protocol fusion schemes ensure message transmission reliability to some extent, their method of directly switching routing strategies at the message source node does not adequately explore the sub-topologies within the MANET, resulting in low utilization of connectable sub-topologies. Therefore, designing a method that efficiently utilizes connectable sub-topologies to improve message transmission reliability is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a message transmission method that integrates prior routing and DTN, so as to improve the reliability of message transmission through the DTN routing mechanism, fully explore the connectable sub-topologies in the MANET network, and thus improve the utilization rate of the connectable network topologies in the MANET, thereby ensuring the stability and practicality of message transmission.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] It integrates prior routing and DTN message transmission methods, and establishes and maintains routing tables in each node of the network based on the prior MANET routing protocol mechanism;

[0007] When the message source node transmits a message to the message destination node:

[0008] S1: Determine whether the prior MANET routing mechanism can be used to transmit messages: if yes, then the prior MANET routing mechanism is used for message transmission; otherwise, use the location-based message copy allocation algorithm and use the DTN mechanism to allocate message copies to relay nodes at the topology boundary of the message source node to make them virtual source nodes.

[0009] S2: Determine whether the message in transmission has been successfully delivered to the message destination node: if yes, the message transmission is successful; otherwise, store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node.

[0010] S3: The virtual source node queries the routing tables of its neighboring nodes to find the routing information of the message destination node by broadcasting routing query information to its neighboring nodes. When an opportunity to establish a connection with the message destination node is found, it jumps to step S1 until the message transmission is completed.

[0011] Preferably, determining whether the a priori MANET routing mechanism can be used to transmit a message means determining whether the routing table of the message source node contains routing information for the message destination node;

[0012] If the routing table of the message source node contains routing information for the message destination node, then the following message sending strategy one will be used:

[0013] S01: Send a message to the destination node based on the priori MANET routing protocol and determine whether the message was sent successfully: if yes, proceed to step S06; otherwise, proceed to step S02.

[0014] S02: Store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node; then update the routing table of each node according to the priori MANET routing protocol mechanism;

[0015] S03: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes;

[0016] S04: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S06; otherwise, jump to step S05.

[0017] S05: Determine if there is routing information for the destination node of the message in the routing table of the neighboring node: if yes, the virtual source node sends a copy of the message to the neighboring node and jumps to step S01; otherwise, jumps to step S02.

[0018] S06: Message sent successfully.

[0019] Preferably, if the source node's own routing table does not contain routing information for the destination node, then the following message sending strategy two is used:

[0020] S11: Let the number of message replicas be n. The message source node queries its own routing table for the number of connectable nodes N, and determines whether there exists N>n-1. If yes, it selects the corresponding source node selection strategy according to the location information generation strategy to generate a virtual source node to store the message replicas, and jumps to step S13; otherwise, it stores the message replicas in each connectable node, making it a virtual source node, and jumps to step S13.

[0021] S12: Send a message to the destination node based on the priori MANET routing protocol, and determine whether the message was sent successfully: if yes, proceed to step S17; otherwise, proceed to step S13.

[0022] S13: Store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node; then update the routing table of each node according to the priori MANET routing protocol mechanism;

[0023] S14: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes;

[0024] S15: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S17; otherwise, jump to step S16.

[0025] S16: Determine whether the routing table of the neighboring node contains the routing information of the destination node of the message: if yes, the virtual source node sends a copy of the message to the neighboring node and jumps to step S12; otherwise, jump to step S13.

[0026] S17: Message sent successfully.

[0027] Preferably, in step S12, the location information is generated using the following two location strategies;

[0028] Location Strategy 1: Gridded location information obtained with the assistance of satellite positioning systems;

[0029] Location strategy 2: Logical location information based on routing tables.

[0030] Preferably, location strategy one generates location information through the following steps:

[0031] 1) A planar map of the network architecture region is pre-embedded, and the side length of the grid within the network architecture region is r;

[0032] 2) Nodes map their geographical location onto a planar map using the satellite positioning system, obtaining their location coordinates (x, y).i ,y i );

[0033] 3) Number the grids within the network architecture region, determine the reference node's position coordinates as (x0, y0) and the grid position number as (1, 1), where x0 ≤ x i y0≤y i ;

[0034] 4) Calculate the node (x) using the following formula. i ,y i The grid position (p) i ,q i ) as its location information;

[0035]

[0036]

[0037] In the formula: [] is the integer symbol, indicating that the smallest integer is selected.

[0038] Preferably, location strategy two refers to the virtual location information established by logical deduction based on the routing table, the node hop count in the neighbor table, and the number of neighbor nodes maintained in the ad hoc network routing protocol when the node cannot obtain its own geographical location information through the satellite positioning system.

[0039] Preferably, in step S12, if the location information is generated through location strategy one, then source node selection strategy one is used: select the outermost n nodes that are evenly distributed in all directions from the connectable nodes as virtual source nodes and store message copies.

[0040] Source node selection strategy one includes the following steps:

[0041] S1201: Calculate the grid position (p0, q0) of the centroid of the internal grid using the following formula;

[0042]

[0043]

[0044] In the formula: (p i ,q i () indicates the grid position of a node within the topology;

[0045] S1202: Calculate the vector X between each node in the topology and the centroid using the following formula. i ,(i=1,2…N);

[0046] X i =(p i -p0,qi -q0), (i = 1, 2…N);

[0047] S1203: Let the number of message replicas be n. Then, the message source node retains one message replica and becomes a virtual source node. Then, with vector X1 as the axis, calculate the angle between the vector of each node in the network architecture region and vector X1.

[0048]

[0049] S1204: Establish a set of reference angles Then the included angle The nodes in the (n-1) grid positions that are closest to the elements in the reference angle set are used as virtual source nodes.

[0050] Preferably, in step S1204, if there are multiple nodes in the same grid location, the functions of each node are considered to be equivalent, and any node is selected as the virtual source node.

[0051] Preferably, if the location information is generated through location strategy two, then source node selection strategy two is used: based on the routing table and neighbor table information maintained by the link state routing strategy, the hop count information from the node to other nodes in the topology and the number of links connected to each node are obtained, and a weighted calculation is performed based on the hop count information and the number of links of each node in the topology, and the n nodes with the larger weights are selected as virtual source nodes.

[0052] Source node selection strategy two includes the following steps:

[0053] S1211: Assume there are N nodes in the network, and then establish a set of hop counts {h1, h2…h...} from the routing table of the message source node to each node in the network. n} and the set of the number of neighboring nodes of each node {l1, l2, ... l n};

[0054] S1212: Normalize the hop count set and the neighbor node count set using the following formula to obtain the hop count parameter h for each node. i The parameter l for the number of neighboring nodes. i ′, (i = 1, 2…N);

[0055]

[0056]

[0057] Where: h max and h min Let {h1, h2, ..., h} represent sets respectively. n The maximum and minimum values ​​in}; l max and lmin Let {l1, l2, ... l} represent the sets respectively. n The maximum and minimum values ​​in}; δ is a correction parameter to prevent the denominator from being 0;

[0058] S1213: Set the weight parameter ω h and ω l Then, the weight of the i-th node is calculated using the following formula;

[0059] ω i =ω h ×h′ i +ω l ×l′ i ;

[0060] S1214: If the message source node generates n message replicas, then the message source node retains 1 replica, and sends the remaining n-1 message replicas to the n-1 nodes with larger weights, making them virtual source nodes.

[0061] The present invention also discloses a readable storage medium storing a computer management program thereon, which, when executed by a processor, implements the steps of the message transmission method for integrating prior routing and DTN as described in the present invention.

[0062] The present invention integrates prior routing and DTN message transmission methods, which has the following advantages:

[0063] This invention receives and forwards message copies through the DTN routing mechanism when a priori MANET route is disconnected, thereby improving the reliability of message transmission. Furthermore, unlike existing priori MANET routes that directly switch routing strategies upon disconnection, this invention designs a virtual source node to broadcast route solicitation messages to neighboring nodes. This allows the virtual source node to continuously seek connectable sub-topologies, maximizing the utilization of connectable sub-topologies. In other words, it fully explores connectable sub-topologies within the MANET network, thereby improving the utilization rate of connectable topologies in the MANET and ultimately enhancing the practicality of message transmission.

[0064] This invention incorporates node location information obtained through a satellite positioning system into the topology convergence and maintenance information received by the source node of the prior routing message. This location information is further processed to form a gridded location information, creating a location-based DTN message replica allocation mode. Based on different location strategies, this invention designs a gridded virtual source node allocation algorithm. This algorithm selects the outermost nodes, evenly distributed in all directions, from the connectable nodes as virtual source nodes, enabling more accurate and effective determination of virtual source nodes and reducing network load caused by redundant information. By using virtual source nodes, this invention better seeks connectable sub-topologies, thereby maximizing the utilization of connectable sub-topologies. It can fully explore connectable sub-topologies in MANET networks, thus improving the utilization rate of connectable topologies in MANETs.

[0065] When satellite system geographic location information cannot be obtained, this invention uses routing tables and neighbor tables maintained by link-state routing policies to obtain hop count information from a node to other nodes in the topology and the number of links connected to each node. Based on the hop count information and link count of each node in the topology, a weighted calculation is performed, and the node with the highest weight is selected as the virtual source node. This allows for more accurate and effective determination of the virtual source node. By using the virtual source node, more connectable sub-topologies can be sought, thus maximizing the utilization of connectable sub-topologies. In other words, it can fully explore connectable sub-topologies in the MANET network, thereby further improving the utilization rate of connectable topologies in the MANET.

[0066] This invention provides two location strategies based on whether satellite system geographic location information can be obtained, making it more suitable for message transmission needs in different scenarios, thereby improving the stability and practicality of message transmission. Attached Figure Description

[0067] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0068] Figure 1 A flowchart for message sending strategy one;

[0069] Figure 2 A flowchart for message sending strategy two;

[0070] Figure 3 A flowchart for generating location information for location strategy one;

[0071] Figure 4 A flowchart for generating location information for location strategy two;

[0072] Figure 5 Flowchart for selecting Strategy 1 for the source node;

[0073] Figure 6 The flowchart for selecting strategy two for the source node. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but only to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0075] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0076] The following detailed explanation illustrates the specific implementation methods:

[0077] Example 1:

[0078] This embodiment discloses a message transmission method that integrates prior routing and DTN.

[0079] It integrates prior routing and DTN message transmission methods, and establishes and maintains routing tables in each node of the network based on the prior MANET routing protocol mechanism;

[0080] When the message source node transmits a message to the message destination node:

[0081] S1: Determine whether the prior MANET routing mechanism can be used to transmit messages: if yes, then the prior MANET routing mechanism is used for message transmission; otherwise, use the location-based message copy allocation algorithm and use the DTN mechanism to allocate message copies to relay nodes at the topology boundary of the message source node to make them virtual source nodes.

[0082] S2: Determine whether the message in transmission has been successfully delivered to the message destination node: if yes, the message transmission is successful; otherwise, store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node.

[0083] S3: The virtual source node queries the routing tables of its neighboring nodes to find the routing information of the message destination node by broadcasting routing query information to its neighboring nodes. When an opportunity to establish a connection with the message destination node is found, it jumps to step S1 until the message transmission is completed.

[0084] In this embodiment, the node will discard the message after its lifespan has expired.

[0085] In a priori MANET routing, each communication node in the network needs to broadcast its own location information and link state information (collectively referred to as control messages) to the network, and establish a routing table for the entire network topology within the node based on the control messages received from other nodes in the network. This process is called topology convergence.

[0086] Due to factors such as changes in node location and communication link status, nodes in the network need to broadcast control messages periodically and receive control messages from other nodes in the network to update their own routing tables. This process is called periodic topology maintenance. When the network topology changes or a new node joins the topology, each node in the network needs to broadcast control information again to update its internal routing table. This process is called event-driven topology maintenance.

[0087] It should be noted that DTN routing mechanism refers to delay-tolerant network routing mechanism. Delay-Tolerant Network (DTN) is a self-organizing network that utilizes node movement to create contact opportunities to transmit information even when there is no source-end connectivity. DTN adds a "carry-carry" element to the traditional "store-and-forward" message exchange mechanism of ad hoc networks, forming a "store-carry-forward" mechanism. That is, after a node receives a message, if it determines that there is no suitable next-hop forwarding node, it stores the message in its local buffer and then "carries" the message until a suitable forwarding opportunity is found to send the message.

[0088] For details, please refer to the jet waiting scheme in the DTN routing mechanism.

[0089] The Spray-and-Wait scheme is a routing protocol strategy based on controlling the number of flooded replicas. This strategy consists of two phases: Spray and Wait.

[0090] In the Spray phase: the message source node will generate L copies of the message and propagate the message copies to other relay nodes it comes into contact with until the number of message copies is 1, after which it will enter the Wait phase;

[0091] During the Wait phase: If the relay node carrying a copy of the message is unable to transmit the message to the message destination node during the Spray phase, the relay node will carry the message copy until it comes into contact with the message destination node to transmit the message.

[0092] This invention can transmit messages through a priori MANET routing protocol, which enables full utilization of the connectable sub-topologies in the network, thereby improving network performance and message transmission efficiency.

[0093] Secondly, this invention receives and forwards message copies through the DTN routing mechanism when a priori MANE route is disconnected, thus improving the reliability of message transmission. Furthermore, unlike existing priori MANE routes that directly switch routing strategies upon disconnection, this invention designs a virtual source node to broadcast route solicitation messages to neighboring nodes. This allows the virtual source node to continuously seek connectable sub-topologies, maximizing the utilization of connectable sub-topologies. In other words, it fully explores connectable sub-topologies within the MANET network, thereby improving the utilization rate of connectable topologies in the MANET and ultimately enhancing the practicality of message transmission.

[0094] Determining whether a priori MANET routing mechanism can be used to transmit a message means checking whether the routing table of the message source node contains routing information for the message destination node.

[0095] Combination Figure 1 As shown, if the routing table of the message source node contains routing information for the message destination node, then the following message sending strategy one will be used:

[0096] S01: Message source node N s Based on the priori MANET routing protocol, the message is directed to the destination node N. d Send the message and determine if it was sent successfully: if yes, proceed to step S06; otherwise, proceed to step S02; (The reason for message failure is: the routing information is invalid, and the message arrives at the routing relay node N). v (The subsequent link has been disconnected)

[0097] S02: Store a copy of the message at the relay node N where the interruption occurred. v This makes it a virtual source node; then the routing tables of each node are updated according to the priori MANET routing protocol mechanism.

[0098] S03: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes (or new neighboring nodes); (if a new neighboring node is found, similar processing is performed) the neighboring node replies with a detection message (in the reply detection message, the original a priori MANET protocol can learn about the routing table of the neighboring node).

[0099] S04: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S06; otherwise, jump to step S05.

[0100] S05: Determine if the neighboring node's routing table contains routing information for the message's destination node. If so, the virtual source node sends a copy of the message to the neighboring node and proceeds to step S01. (The reason for message transmission failure is: the neighboring node's routing table to the message's destination node is invalid, and the message arrives at the routing relay node N.) v (If the subsequent link has been disconnected at this time); otherwise, proceed to step S02.

[0101] S06: Message sent successfully.

[0102] Combination Figure 2 As shown, if the source node's own routing table does not contain routing information for the destination node, then the following message sending strategy two will be used:

[0103] S11: Let the number of message replicas be n (n=4 is recommended). The message source node queries its own routing table for connectable nodes and their location information (mesh IP information). The number of connectable nodes is N. Determine if there exists N>n-1. If yes, select the corresponding source node selection strategy according to the location information generation strategy to generate a virtual source node to store the message replica, and jump to step S13. Otherwise, store the message replica in each connectable node, making it a virtual source node, and jump to step S13.

[0104] S12: Send a message to the destination node based on the priori MANET routing protocol, and determine whether the message was sent successfully: if yes, proceed to step S17; otherwise, proceed to step S13.

[0105] S13: Store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node; then update the routing table of each node according to the priori MANET routing protocol mechanism;

[0106] S14: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes;

[0107] S15: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S17; otherwise, jump to step S16.

[0108] S16: Determine whether the routing table of the neighboring node contains the routing information of the destination node of the message: if yes, the virtual source node sends a copy of the message to the neighboring node and jumps to step S12; otherwise, jump to step S13.

[0109] S17: Message sent successfully.

[0110] In practice, location information is generated using the following two location strategies;

[0111] Location Strategy 1: Gridded location information obtained with the assistance of satellite positioning systems;

[0112] Location strategy 2: Logical location information based on routing tables.

[0113] Combination Figure 3 As shown, location strategy one generates location information through the following steps:

[0114] 1) A planar map of the network architecture region is pre-embedded, and the side length of the grid within the network architecture region is r;

[0115] 2) Nodes map their geographical location onto a planar map using the satellite positioning system, obtaining their location coordinates (x, y). i ,y i );

[0116] 3) Number the grids within the network architecture region, determine the reference node's position coordinates as (x0, y0) and the grid position number as (1, 1), where x0 ≤ x i y0≤y i ;

[0117] 4) Calculate the node (x) using the following formula. i ,y i The grid position (p) i ,q i ) as its location information;

[0118]

[0119]

[0120] In the formula: [] is the integer symbol, indicating that the smallest integer is selected.

[0121] Combination Figure 4 As shown, location strategy two refers to the virtual location information established by logical deduction based on the routing table, the node hop count in the neighbor table, and the number of neighbor nodes maintained in the ad hoc network routing protocol when the node cannot obtain its own geographical location information through the satellite positioning system.

[0122] In the specific implementation process, if the location information is generated through location strategy one, then source node selection strategy one is used: select the outermost n nodes that are evenly distributed in all directions from the connectable nodes as virtual source nodes and store message copies.

[0123] Combination Figure 5 As shown, source node selection strategy one includes the following steps:

[0124] S1201: Calculate the grid position (p0, q0) of the centroid of the internal grid using the following formula;

[0125]

[0126]

[0127] In the formula: (p i ,q i () indicates the grid position of a node within the topology;

[0128] S1202: Calculate the vector X between each node in the topology and the centroid using the following formula. i ,(i=1,2…N);

[0129] X i =(p i -p0,qi -q0), (i = 1, 2…N);

[0130] S1203: Let the number of message replicas be n. Then, the message source node retains one message replica and becomes a virtual source node. Then, with vector X1 as the axis, calculate the angle between the vector of each node in the network architecture region and vector X1.

[0131]

[0132] S1204: Establish a set of reference angles Then the included angle The nodes within the (n-1) grid positions closest to an element in the reference angle set are designated as virtual source nodes. If multiple nodes exist within the same grid position, they are considered functionally equivalent, and any one of them is selected as the virtual source node.

[0133] In the specific implementation process, if the location information is generated through location strategy two, then source node selection strategy two is used: based on the routing table and neighbor table information maintained by the link state routing strategy, the hop count information from the node to other nodes in the topology and the number of links connected to each node are obtained. The hop count information and the number of links of each node in the topology are weighted and calculated, and the n nodes with the larger weights are selected as virtual source nodes.

[0134] In this embodiment, the link-state routing strategy is a routing algorithm that selects routes based on link-state information using a greedy algorithm. Each node needs to monitor its neighbors by broadcasting Hello packets to them and flooding its own link-state packets across the entire network.

[0135] Combination Figure 6 As shown, source node selection strategy two includes the following steps:

[0136] S1211: Assume there are N nodes in the network, and then establish a set of hop counts {h1, h2…h...} from the routing table of the message source node to each node in the network. n} and the set of the number of neighboring nodes of each node {l1, l2, ... l n};

[0137] S1212: Normalize the hop count set and the neighbor node count set using the following formula to obtain the hop count parameter h for each node. i The parameter l for the number of neighboring nodes. i ′, (i = 1, 2…N);

[0138]

[0139]

[0140] Where: h max and h min Let {h1, h2, ..., h} represent sets respectively. n The maximum and minimum values ​​in}; l max and l min Let {l1, l2, ... l} represent the sets respectively. n The maximum and minimum values ​​in}; δ is a correction parameter to prevent the denominator from being 0, theoretically infinitesimal, but temporarily taken as 10 in this formula. -6 ;

[0141] S1213: Set the weight parameter ω h and ω l (assuming ω) h =ω l =0.5), and then calculate the weight of the i-th node using the following formula;

[0142] ω i =ω h ×h′ i +ω l ×l′ i ;

[0143] S1214: If the message source node generates n message replicas, then the message source node retains 1 replica, and sends the remaining n-1 message replicas to the n-1 nodes with larger weights, making them virtual source nodes.

[0144] This invention receives and forwards message copies through the DTN routing mechanism when a priori MANET route is disconnected, thereby improving the reliability of message transmission. Furthermore, unlike existing priori MANET routes that directly switch routing strategies upon disconnection, this invention designs a virtual source node to broadcast route solicitation messages to neighboring nodes. This allows the virtual source node to continuously seek connectable sub-topologies, maximizing the utilization of connectable sub-topologies. In other words, it fully explores connectable sub-topologies within the MANET network, thereby improving the utilization rate of connectable topologies in the MANET and ultimately enhancing the practicality of message transmission.

[0145] Secondly, this invention incorporates node location information obtained through a satellite positioning system into the topology convergence and maintenance information received by the source node of the priori routing message. This location information is further processed to form a gridded location information, creating a location-based DTN message replica allocation mode. Based on different location strategies, this invention designs a gridded virtual source node allocation algorithm, selecting the outermost nodes that are evenly distributed in all directions from the connectable nodes as virtual source nodes. This allows for more accurate and effective determination of virtual source nodes, reducing network load caused by redundant information. This invention, through virtual source nodes, better seeks connectable sub-topologies, thereby maximizing the utilization of connectable sub-topologies. It can fully explore connectable sub-topologies in MANET networks, thus improving the utilization rate of connectable topologies in MANETs.

[0146] Furthermore, when satellite system geographic location information cannot be obtained, this invention obtains the hop count information from a node to other nodes in the topology and the number of links connected to each node based on the routing table and neighbor table information maintained by the link-state routing policy. A weighted calculation is performed based on the hop count information and link count of each node in the topology, and the node with the largest weight is selected as the virtual source node. This allows for more accurate and effective determination of the virtual source node. By using the virtual source node, more connectable sub-topologies can be sought, thereby maximizing the utilization of connectable sub-topologies. In other words, it can fully explore the connectable sub-topologies in the MANET network, thereby further improving the utilization rate of connectable topologies in the MANET.

[0147] Finally, this invention provides two location strategies based on whether satellite system geographic location information can be obtained, which can better adapt to message transmission needs in different scenarios, thereby improving the stability and practicality of message transmission.

[0148] Example 2:

[0149] This embodiment discloses a readable storage medium.

[0150] A readable storage medium stores a computer management program thereon, which, when executed by a processor, implements the steps of the fusion of priori routing and DTN message transmission method of the present invention. The readable storage medium may be a device with readable storage capabilities, such as a USB flash drive or a computer.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A message transmission method integrating priori routing and DTN, characterized in that: The routing table is established and maintained in each node of the network based on the prior MANET routing protocol mechanism; When the message source node transmits a message to the message destination node: S1: Determine whether the prior MANET routing mechanism can be used to transmit messages: if yes, then the prior MANET routing mechanism is used for message transmission; otherwise, use the location-based message copy allocation algorithm and use the DTN mechanism to allocate message copies to relay nodes at the topology boundary of the message source node to make them virtual source nodes. Determining whether a priori MANET routing mechanism can be used to transmit a message means checking whether the routing table of the message source node contains routing information for the message destination node. If the routing table of the message source node contains routing information for the message destination node, then the following message sending strategy one will be used: S01: Send a message to the destination node based on the priori MANET routing protocol and determine whether the message was sent successfully: if yes, proceed to step S06; otherwise, proceed to step S02. S02: Store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node; then update the routing table of each node according to the priori MANET routing protocol mechanism; S03: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes; S04: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S06; otherwise, jump to step S05. S05: Determine if there is routing information for the destination node of the message in the routing table of the neighboring node: if yes, the virtual source node sends a copy of the message to the neighboring node and jumps to step S01; otherwise, jumps to step S02. S06: Message sent successfully; If the source node does not have routing information for the destination node in its own routing table, then the following message sending strategy two will be used: S11: Let the number of message replicas be n. The message source node queries its own routing table for the number of connectable nodes N, and determines whether there exists N>n-1. If yes, it selects the corresponding source node selection strategy according to the location information generation strategy to generate a virtual source node to store the message replicas, and jumps to step S13; otherwise, it stores the message replicas in each connectable node, making it a virtual source node, and jumps to step S13. S12: Send a message to the destination node based on the priori MANET routing protocol, and determine whether the message was sent successfully: if yes, proceed to step S17; otherwise, proceed to step S13. S13: Store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node; then update the routing table of each node according to the priori MANET routing protocol mechanism; S14: The virtual source node will periodically or eventually check the routing tables of its neighboring nodes; S15: Determine whether the corresponding neighbor node is the message destination node: if yes, send the message to the message destination node and jump to step S17; otherwise, jump to step S16. S16: Determine whether the routing table of the neighboring node contains the routing information of the destination node of the message: if so, the virtual source node sends a copy of the message to the neighboring node and jumps to step S12. Otherwise, proceed to step S13; S17: Message sent successfully; Location information is generated using the following two location strategies; Location Strategy 1: Gridded location information obtained with the assistance of satellite positioning systems; Location Strategy 2: Based on logical location information formed by the routing table; If the location information is generated through location strategy one, then source node selection strategy one is used: select the outermost n nodes that are evenly distributed in all directions from the connectable nodes as virtual source nodes and store message copies. Source node selection strategy one includes the following steps: S1201: Calculate the grid position (p0, q0) of the centroid of the internal grid using the following formula; In the formula: (p i ,q i () indicates the grid position of a node within the topology; S1202: Calculate the vector X between each node in the topology and the centroid using the following formula. i ,(i=1,2…N); X i =(p i -p0,q i -q0),(i=1,2…N); S1203: Let the number of message replicas be n. Then, the message source node retains one message replica and becomes a virtual source node. Then, with vector X1 as the axis, calculate the angle between the vector of each node in the network architecture region and vector X1. (i = 1, 2, ..., N); S1204: Establish a set of reference angles Then the included angle The nodes within the (n-1) grid positions that are closest to the elements in the reference angle set are used as virtual source nodes; S2: Determine whether the message in transmission has been successfully delivered to the message destination node: if yes, the message transmission is successful; otherwise, store a copy of the message at the relay node where the communication link is interrupted, making it a virtual source node. S3: The virtual source node queries the routing tables of its neighboring nodes to find the routing information of the message destination node by broadcasting routing query information to its neighboring nodes. When an opportunity to establish a connection with the message destination node is found, it jumps to step S1 until the message transmission is completed.

2. The message transmission method integrating priori routing and DTN as described in claim 1, characterized in that: Location strategy one generates location information through the following steps: 1) A planar map of the network architecture region is pre-embedded, and the side length of the grid within the network architecture region is r; 2) Nodes map their geographical location onto a planar map using the satellite positioning system, obtaining their location coordinates (x, y). i ,y i ); 3) Number the grids within the network architecture region, determine the reference node's position coordinates as (x0, y0) and the grid position number as (1, 1), where x0 ≤ x i y0≤y i ; 4) Calculate the node (x) using the following formula. i ,y i The grid position (p) i ,q i ) as its location information; In the formula: [] is the integer symbol, indicating that the smallest integer is selected.

3. The message transmission method integrating priori routing and DTN as described in claim 1, characterized in that: Location strategy two refers to the virtual location information established by logical deduction based on the routing table, the node hop count in the neighbor table, and the number of neighbor nodes maintained in the ad hoc network routing protocol when a node cannot obtain its own geographical location information through the satellite positioning system.

4. The message transmission method integrating priori routing and DTN as described in claim 1, characterized in that: In step S1204, if there are multiple nodes in the same grid location, the functions of each node are considered to be equivalent, and any node is selected as the virtual source node.

5. The message transmission method integrating priori routing and DTN as described in claim 1, characterized in that: If the location information is generated through location strategy two, then source node selection strategy two is used: based on the routing table and neighbor table information maintained by the link state routing strategy, the hop count information from the node to other nodes in the topology and the number of links connected to each node are obtained. The hop count information and the number of links of each node in the topology are weighted and calculated, and the n nodes with the larger weights are selected as virtual source nodes. Source node selection strategy two includes the following steps: S1211: Assume there are N nodes in the network, and then establish a set of hop counts {h1, h2…h...} from the routing table of the message source node to each node in the network. n } and the set of the number of neighboring nodes of each node {l1, l2, ... l n }; S1212: Normalize the hop count set and the neighbor node count set using the following formula to obtain the hop count parameter h for each node. i The parameter l for the number of neighboring nodes. i ′, (i = 1, 2…N); Where: h max and h min Let {h1, h2, ..., h} represent sets respectively. n The maximum and minimum values ​​in}; l max and l min Let {l1, l2, ... l} represent the sets respectively. n The maximum and minimum values ​​in}; δ is a correction parameter to prevent the denominator from being 0; S1213: Set the weight parameter ω h and ω l Then, the weight of the i-th node is calculated using the following formula; oh i =ω h ×h i ′ +oh l ×l i ′ ; S1214: If the message source node generates n message replicas, then the message source node retains 1 replica, and sends the remaining n-1 message replicas to the n-1 nodes with larger weights, making them virtual source nodes.

6. A readable storage medium, characterized in that, It stores a computer management program, which, when executed by a processor, implements the steps of the method for integrating prior routing and DTN message transmission as described in any one of claims 1-5.

Images