CN-115767665-B - Message transmission method integrating prior routing and DTN and storage medium

CN115767665BCN 115767665 BCN115767665 BCN 115767665BCN-115767665-B

Abstract

The invention particularly relates to a message transmission method and a storage medium integrating prior routing and DTN. The method comprises the steps of establishing and maintaining a routing table in each node of a network based on a priori MANET routing protocol mechanism, firstly adopting the priori MANET routing mechanism to transmit messages when message source nodes transmit messages to message destination nodes, otherwise using a message copy distribution algorithm based on position information to distribute message copies to relay nodes at topological boundaries of the message source nodes by using a DTN mechanism to enable the message copies to become virtual source nodes, enabling the message copies to be stored in the relay nodes at interruption positions to become virtual source nodes when the message transmission is unsuccessful, broadcasting routing query information to neighbor nodes by the virtual source nodes, inquiring the routing tables of the neighbor nodes, and repeating the steps when finding opportunities for establishing connection with the message destination nodes. The invention can improve the reliability of message transmission through a DTN routing mechanism and fully explore the connectable sub-topology in the MANET network.

Inventors

MA DAWEI
TIAN CHUNYUAN
HU YANZHI
CHEN QIHANG
HUANG WEI
WANG SHIJIE
Hong Liteng
YIN CAIHUA
HUANG HAO
ZHANG SHIWEI

Assignees

中国人民解放军陆军工程大学

Dates

Publication Date: 20260508
Application Date: 20220928

Claims (6)

1. A message transmission method integrating prior routing and DTN is characterized in that a routing table is built and maintained in each node of a network based on a prior MANET routing protocol mechanism; When a message source node transmits a message to a message destination node: S1, judging whether a priori MANET routing mechanism can be adopted to transmit the message, if so, adopting the priori MANET routing mechanism to transmit the message, otherwise, using a message copy allocation algorithm based on the position information, and using a DTN mechanism to allocate the message copy to a relay node at a topological boundary of a message source node so as to change the message copy into a virtual source node; Judging whether the prior MANET routing mechanism can be adopted to transmit the message refers to judging whether the routing table of the message source node has the routing information of the message destination node or not; if the routing table of the message source node has the routing information of the message destination node, the following message sending strategy I is used: s01, sending a message to a message destination node based on a priori MANET routing protocol, and judging whether the message is sent successfully, if so, jumping to the step S06, otherwise, jumping to the step S02; S02, storing the message copy in a relay node at the position of communication link interruption to enable the message copy to be a virtual source node; s03, periodically or event-wise checking a routing table of a neighbor node by the virtual source node; S04, judging whether the corresponding neighbor node is a message destination node, if so, sending the message to the message destination node, and jumping to the step S06, otherwise, jumping to the step S05; S05, judging whether the routing table of the neighbor node has the routing information of the message destination node or not, if so, transmitting the message copy to the neighbor node by the virtual source node, and jumping to the step S01, otherwise jumping to the step S02; s06, successful message sending; if the routing table of the message source node does not have the routing information of the message destination node, the following message sending strategy II is used: S11, setting the number of message copies as N, inquiring the number N of communicable nodes in a self routing table by a message source node, and judging whether N > N-1 exists or not, if so, selecting a corresponding source node selection strategy according to the generation position strategy of the position information to generate a virtual source node storage message copy, and jumping to the step S13; S12, sending a message to a message destination node based on a priori MANET routing protocol, and judging whether the message is sent successfully, if so, jumping to a step S17, otherwise, jumping to a step S13; S13, storing the message copy in a relay node at the position of communication link interruption to enable the message copy to be a virtual source node; s14, the virtual source node periodically or event-wise checks the routing table of the neighbor node; S15, judging whether the corresponding neighbor node is a message destination node, if so, sending the message to the message destination node, and jumping to the step S17, otherwise, jumping to the step S16; s16, judging whether the routing table of the neighbor node contains the routing information of the message destination node or not, if yes, the virtual source node sends the message copy to the neighbor node and jumps to the step S12, otherwise, jumps to the step S13; s17, successful message sending; the position information is generated by the following two position strategies; the first position strategy is grid position information which is assisted by a satellite positioning system; The second position strategy is logic position information formed based on the routing table; If the position information is generated through the first position strategy, a first source node selection strategy is used, wherein n nodes which are uniformly distributed along each direction are selected from the communicable nodes as virtual source nodes and message copies are stored; the source node selection policy one comprises the following steps: s1201, calculating a grid position (p 0 ,q 0 ) where a grid gravity center point in the topology is located through the following formula; Wherein (p i ,q i ) represents the grid position of the node in the topology; S1202, calculating a vector X i of each node and a gravity center point in the topology by the following formula, (i=1, 2..n); X i ＝(p i -p 0 ,q i -q 0 ),(i=1,2...N); S1203, setting the number of message copies as n, then reserving one message copy by the message source node to be changed into a virtual source node, and calculating the included angle between each node vector and the vector X 1 in the network architecture area by taking the vector X 1 as an axis (i=1,2...N); S1204 establishing a reference angle set Then the included angle is formed The nodes in the (n-1) grid positions closest to the elements in the reference angle set are used as virtual source nodes; s2, judging whether the message in transmission is successfully sent to a message destination node, if so, the message is successfully transmitted, otherwise, storing a message copy in a relay node at the position where a communication link is interrupted, and enabling the message copy to be a virtual source node; And S3, the virtual source node queries a routing table of the neighbor node to find the routing information of the message destination node in a mode of broadcasting routing solicitation information to the neighbor node, and when finding the opportunity of establishing connection with the message destination node, the virtual source node jumps to the step S1 until the message transmission is completed.
2. The method for message transmission merging a priori routing and DTN of claim 1, wherein the location policy one generates location information by: 1) A planar map of a network architecture area is implanted in advance, and the side length of a grid in the network architecture area is r; 2) The node maps the geographic position of the node to a plane map according to a satellite positioning system to obtain a position coordinate (x i ,y i ); 3) Numbering grids in the network architecture area, and determining the position coordinates of the reference nodes as (x 0 ,y 0 ) and the grid position numbers as (1, 1), wherein x 0 ≤x i ,y 0 ≤y i ; 4) Calculating a grid position (p i ,q i ) where the node (x i ,y i ) is located as its position information by the following formula; Wherein [ (] is a whole-number symbol) and represents that the minimum integer is selected.
3. The method of claim 1, wherein the second location policy means virtual location information established by logic deduction according to a routing table maintained in an ad hoc network routing protocol, node hops in a neighbor table and neighbor node number information when the node cannot acquire its own geographic location information through a satellite positioning system.
4. The message transmission method combining a priori routing and DTN according to claim 1, wherein in step S1204, if there are multiple nodes in the same grid location, each node is considered to be functionally equivalent, and one node is selected as a virtual source node.
5. The message transmission method integrating prior routing and DTN according to claim 1, wherein if the position information is generated by a second position strategy, a second source node selection strategy is used, hop count information from the node to other nodes in the topology and the number of links connected with the nodes are obtained based on a routing table and neighbor table information maintained by a link state routing strategy, weighting calculation is performed according to the hop count information and the number of links of the nodes in the topology, and n nodes with large weights are selected as virtual source nodes; the second source node selection strategy comprises the following steps: S1211, setting the number of nodes in the network as N, and then establishing a hop count set { h 1 ,h 2 …h n } reaching each node in the network and a neighbor node number set { l 1 ,l 2 …l n } of each node in a message source node routing table; S1212, normalizing the hop count set and the neighbor node number set through the following formula to obtain a hop count parameter h i 'and a neighbor node number parameter l i ' of each node (i=1, 2..N); wherein h max and h min respectively represent the maximum and minimum values in the set { h 1 ,h 2 …h n }, l max and l min respectively represent the maximum and minimum values in the set { l 1 ,l 2 …l n }, and δ is a correction parameter for preventing the denominator from being 0; S1213, setting weight parameters omega h and omega l , and then calculating the weight of the ith node through the following formula; ω i ＝ω h ×h i ′ +ω l ×l i ′ ; S1214, if the message source node generates n message copies, the message source node keeps 1 copy, and the rest n-1 message copies are sent to n-1 nodes with larger weight, so that the message source node becomes a virtual source node.
6. A readable storage medium, having stored thereon a computer management class program which, when executed by a processor, implements the steps of the message transmission method of merging a priori routing and DTN as claimed in any one of claims 1-5.

Description

Message transmission method integrating prior routing and DTN and storage medium Technical Field The invention relates to the technical field of wireless network protocols, in particular to a message transmission method and a storage medium integrating prior routing and DTN. Background A priori routing (Proactive Routing Protocol), also known as proactive routing or table-driven routing, is proposed specifically for MANET (mobile ad hoc network) environments. The main characteristic of the prior routing is that each node in the network stably maintains a routing table reaching other nodes in the network. When the network topology changes, the node can acquire the change information in time and update the routing table of the node. Each node knows the routes to all other nodes, so that the route to the message destination node can be obtained immediately as soon as the message source node needs to send a message. In the prior art, the problem of discontinuous network connection easily occurs in the message transmission method based on the prior MANET routing protocol, namely, the corresponding routing information is invalid, and the subsequent links are disconnected when the message arrives at the routing relay node, so that the message or the message copy cannot be effectively transmitted to the message destination node. In order to solve the problem, in the prior art, message transmission is generally completed by integrating multiple routing protocols, namely, when the first-check MANET route is disconnected, the message transmission is completed by switching to other routing strategies through a serial switching mechanism. However, although the reliability of message transmission is guaranteed to a certain extent by the existing multiple routing protocol fusion scheme, the sub-topology in the MANET is not fully explored by directly switching the routing policy through the message source node, so that the utilization rate of the connectable sub-topology in the network is very low. Therefore, how to design a method for improving the reliability of message transmission by efficiently utilizing the connectable sub-topology in the network is a technical problem to be solved. Disclosure of Invention Aiming at the defects of the prior art, the technical problem to be solved by the invention is how to provide a message transmission method integrating prior routing and DTN, so as to improve the reliability of message transmission through a DTN routing mechanism, fully explore the connectable sub-topology in a MANET network, and further improve the utilization rate of the connectable network topology in the MANET, thereby ensuring the stability and the practicability of message transmission. In order to solve the technical problems, the invention adopts the following technical scheme: A message transmission method integrating prior routing and DTN is used for establishing and maintaining a routing table in each node of a network based on a prior MANET routing protocol mechanism; When a message source node transmits a message to a message destination node: S1, judging whether a priori MANET routing mechanism can be adopted to transmit the message, if so, adopting the priori MANET routing mechanism to transmit the message, otherwise, using a message copy allocation algorithm based on the position information, and using a DTN mechanism to allocate the message copy to a relay node at a topological boundary of a message source node so as to change the message copy into a virtual source node; s2, judging whether the message in transmission is successfully sent to a message destination node, if so, the message is successfully transmitted, otherwise, storing a message copy in a relay node at the position where a communication link is interrupted, and enabling the message copy to be a virtual source node; And S3, the virtual source node queries a routing table of the neighbor node to find the routing information of the message destination node in a mode of broadcasting routing solicitation information to the neighbor node, and when finding the opportunity of establishing connection with the message destination node, the virtual source node jumps to the step S1 until the message transmission is completed. Preferably, determining whether the message can be transmitted by adopting the prior MANET routing mechanism refers to determining whether the routing table of the message source node has the routing information of the message destination node; if the routing table of the message source node has the routing information of the message destination node, the following message sending strategy I is used: s01, sending a message to a message destination node based on a priori MANET routing protocol, and judging whether the message is sent successfully, if so, jumping to the step S06, otherwise, jumping to the step S02; S02, storing the message copy in a relay node at the position of communication link interruption to enable the