A Modeling Method for Tropospheric Scattering Communication Networks Based on OPNET Software

Abstract

This invention relates to the field of communication technology and provides a modeling method for tropospheric scattering communication networks based on OPNET software. The method includes: establishing a tropospheric scattering communication channel model and calculating the signal reception power; establishing a central node model and peripheral node models of the tropospheric scattering communication network for calculating network routing and determining the receiving node for data packets; establishing a transmission protocol model for the tropospheric scattering communication network, including communication link establishment protocols between the central node and peripheral nodes, and between central nodes, for calculating the shortest route for data packets to reach the target subnet; and simulating the tropospheric scattering communication network based on the established model. This invention can construct network models with different topologies, and through simulation, it obtains network performance indicators such as average end-to-end latency and average traffic volume, providing a good experimental platform for research on the networking and application modes of tropospheric scattering communication networks.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a method for modeling tropospheric scattering communication networks based on OPNET software. Background Technology

[0002] Tropospheric scattering communication utilizes the scattering effect of the medium in the atmosphere to propagate signals. It can transmit various signals such as voice, images, and video, and is a method for achieving beyond-line-of-sight communication. Tropospheric scattering communication has advantages such as large transmission capacity, long single-hop transmission distance, and strong transmission channel resilience, and is widely used in emergency communication and other fields. Networking applications of scattering communication represent the main future development direction of tropospheric scattering communication. However, currently, scattering communication is mostly used in point-to-point communication scenarios, making it difficult to configure the appropriate hardware and software environment required for scattering communication network experiments. Furthermore, scattering communication networks are large-scale, making it difficult to analyze and organize their operation solely through experience and mathematical models.

[0003] Network simulation is an objective and reliable network planning and design technique. It can simultaneously verify and compare multiple different design scheme models and obtain quantitative network performance prediction data, providing a reliable basis for scheme verification and comparison. Using OPNET to model and simulate tropospheric scattering communication networks allows for effective and objective analysis and evaluation of the overall performance of network organization and application schemes during the research of tropospheric scattering communication network organization and application modes, verifying the scientific validity, rationality, and feasibility of the schemes.

[0004] Currently, existing technologies only involve studying the fading characteristics and waveform features of scattering channels through simulation tools, but lack network simulation studies of tropospheric scattering communication networks. Summary of the Invention

[0005] This invention provides a channel simulation method for tropospheric scattering communication to overcome the shortcomings of the prior art. It models the channel, packet format, routing protocol, network central node, network peripheral nodes, and network topology to construct a tropospheric scattering communication network model, and performs simulation based on the model to analyze the overall network performance.

[0006] This invention provides a method for modeling tropospheric scattering communication networks based on OPNET software, comprising:

[0007] A tropospheric scattering communication channel model is established, the link propagation loss is calculated based on the input parameters, and the signal reception power is calculated based on the transmit power and the link propagation loss.

[0008] Based on each node of the tropospheric scattering communication network, a central node model and a peripheral node model of the tropospheric scattering communication network are established respectively. The central node model and the peripheral node model calculate the network route and determine the receiving node of the data packet according to the target address of the data packet.

[0009] Establish a transmission protocol model for a tropospheric scattering communication network, including communication link establishment protocols between central nodes and surrounding nodes, as well as communication link establishment protocols between central nodes. Obtain all link information between all central nodes, and calculate the shortest route for data packets to reach the target subnet based on the link information.

[0010] Based on the tropospheric scattering communication channel model, the central node model, the peripheral node model, and the tropospheric scattering communication network transmission protocol model, a tropospheric scattering communication network model is constructed, and the tropospheric scattering communication network is simulated.

[0011] According to the OPNET software-based tropospheric scattering communication network modeling method provided by the present invention, the calculation of the link propagation loss includes:

[0012] The input parameters obtained include climate factors, non-uniformity coefficient, signal frequency, refractive index, antenna angle, great circle distance, and antenna gain;

[0013] The equivalent Earth radius is calculated based on the refractive index; the scattering angle, the lowest point height of the scatterer, and the highest point height of the scatterer are calculated based on the equivalent Earth radius, the antenna angle, and the great circle distance; the antenna dielectric coupling loss is calculated based on the antenna gain.

[0014] The link propagation loss is calculated using climate factors, non-uniformity coefficient, signal frequency, lowest point height of the scatterer, highest point height of the scatterer, and antenna medium coupling loss.

[0015] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided. The central node model of the tropospheric scattering communication network includes an antenna module, a wireless receiver module, a wireless transmitter module, a physical access module, an intermediate module, a network management module, a routing management module, a service source data module, and a reception statistics module.

[0016] The service source data module is used to generate data packets, and the routing management module is used to calculate network routes based on the destination address of the data packets and record the network routes in the packets. If the destination address of the data packets is the current node, the packets are received and sent to the receiving statistics module for data statistics. If the destination address of the data packets is another node, the packets are sent to the network management module.

[0017] After receiving the data packet sent by the routing management module, the network management module confirms the transmitter port based on the routing information, records it in the data packet, inserts it into the buffer queue, and sends it to the intermediate module when the channel is idle.

[0018] The intermediate module is used to send and receive data packets between the network management module and the physical access module; the physical access module is connected to the wireless receiver module and the wireless transmitter module respectively, receives data packets received by the antenna module through the wireless receiver module, and sends the data packets through the antenna module through the wireless transmitter module.

[0019] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided, wherein the physical access module is used to determine whether the current channel is idle, and to transmit data packets when the channel is idle;

[0020] After receiving the data packet sent by the physical access module, if the destination address of the data packet is the current node or the data packet does not contain routing information, the network management module sends the data packet to the routing management module.

[0021] If the destination address of the data packet is not that of this node and the data packet contains routing information, then the transmitter port for forwarding is determined according to the existing routing information, and recorded in the data packet, inserted into the buffer queue, and sent when the channel is idle.

[0022] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided. The peripheral node model of the tropospheric scattering communication network includes an antenna module, a wireless receiver module, a wireless transmitter module, a physical access module, an intermediate module, a network management module, a routing management module, a service source data module, and a reception statistics module.

[0023] The network management module is used to receive data packets sent by the service source data module, calculate the receiver port and transmitter port of the central node corresponding to the current surrounding nodes, insert the data packets into the buffer sequence, and send them when the channel is idle.

[0024] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided, wherein the communication link establishment protocol between the central node and surrounding nodes includes:

[0025] Each central node sends probe frames to the surrounding nodes of the protocol network to be accessed;

[0026] After receiving the detection frame, the surrounding nodes send a response frame back to the central node;

[0027] After receiving the response frame, the central node establishes a full-duplex link with the corresponding surrounding nodes.

[0028] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided, wherein the communication link establishment protocol between the central nodes includes:

[0029] Each of the central nodes sends probe frames to the other central nodes;

[0030] After receiving the probe frame from the current central node, other central nodes complete the establishment of a unidirectional link; after receiving the probe frame from other central nodes, the current central node completes the establishment of a unidirectional link; thus establishing a full-duplex link between the current central node and other central nodes.

[0031] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided, which calculates the shortest route for data packets to reach the target subnet based on the link information, including:

[0032] Read the sending subnet information and receiving subnet information from the data packet, and initialize the shortest route information table;

[0033] The sending subnet node is added to the shortest route information table, other nodes that the subnet node can reach are calculated, and the link weight of each other node is calculated by weighting according to the link bandwidth, latency and bit error rate, and the total shortest path weight of the subnet node is updated.

[0034] Select the node with the smallest total weight of the shortest path from the other reachable nodes and add it to the shortest route information table;

[0035] The shortest route to the target subnet is calculated based on the latest shortest route information table, and the shortest route is written into the data packet;

[0036] Starting from the target subnet, query the previous node of the target subnet until the sending subnet node is found. After the query is completed, write the static routing information into the data packet and send the data packet; if the sending subnet cannot be found, destroy the data packet.

[0037] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0038] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0039] This invention provides a tropospheric scattering communication network modeling method based on OPNET software. By modeling the channel, packet format, routing protocol, network central node, network peripheral nodes, and network topology, a tropospheric scattering communication network model is constructed. Simulation based on this model can efficiently analyze the overall network performance. By using the tropospheric scattering communication network process model and node model, network models with different topologies can be formed. Through simulation, indicators such as average end-to-end latency and average traffic volume are obtained, providing a good experimental platform for the research of tropospheric scattering communication network networking and application modes. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating the tropospheric scattering communication network modeling method provided by the present invention;

[0042] Figure 2 This is a schematic diagram of the received power algorithm flow of the tropospheric scattering communication network modeling method provided by the present invention;

[0043] Figure 3 This is a schematic diagram of the central node model of the tropospheric scattering communication network provided by the present invention;

[0044] Figure 4 This is a schematic diagram of the data packet format of the tropospheric scattering communication network modeling method provided by the present invention;

[0045] Figure 5 This is a flowchart of the routing protocol between central nodes in the tropospheric scattering communication network modeling method provided by the present invention;

[0046] Figure 6 This is a schematic diagram of a scattering communication network based on the tropospheric scattering communication network modeling method provided by the present invention;

[0047] Figure 7 This is one of the simulation effect diagrams of the tropospheric scattering communication network modeling method provided by the present invention;

[0048] Figure 8 This is the second simulation effect diagram of the tropospheric scattering communication network modeling method provided by the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or apparatus.

[0051] It should be noted that the terms "first" and "second" used in this invention merely distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" can be interchanged in a specific order or sequence where permissible. It should be understood that the objects distinguished by "first" and "second" can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those described or illustrated herein.

[0052] In one embodiment, such as Figure 1 As shown, the present invention provides a method for modeling tropospheric scattering communication networks based on OPNET software, comprising:

[0053] A tropospheric scattering communication channel model is established, the link propagation loss is calculated based on the input parameters, and the signal reception power is calculated based on the transmit power and the link propagation loss.

[0054] Based on each node of the tropospheric scattering communication network, a central node model and a peripheral node model of the tropospheric scattering communication network are established respectively. The central node model and the peripheral node model calculate the network route and determine the receiving node of the data packet according to the target address of the data packet.

[0055] Establish a transmission protocol model for a tropospheric scattering communication network, including communication link establishment protocols between central nodes and surrounding nodes, as well as communication link establishment protocols between central nodes. Obtain all link information between all central nodes, and calculate the shortest route for data packets to reach the target subnet based on the link information.

[0056] Based on the tropospheric scattering communication channel model, the central node model, the peripheral node model, and the tropospheric scattering communication network transmission protocol model, a tropospheric scattering communication network model is constructed, and the tropospheric scattering communication network is simulated.

[0057] Specifically, in the OPNET simulation software, the channel model is constructed using 14 interconnected pipes to simulate the transmission of data packets within the pipes. Simulation is performed by setting the attributes of the wireless transceiver / transmitter. Pipe stage 7 is used to calculate the received power, based on propagation loss, antenna gain, superimposed bandwidth, and transmit power. The tropospheric scattering communication channel model modifies the received power calculation model, employing the CCIR method to calculate the received power. The specific calculation process is as follows: Figure 2 As shown:

[0058] Calculating the link propagation loss includes:

[0059] The input parameters obtained include climate factors, non-uniformity coefficient, signal frequency, refractive index, antenna angle, great circle distance, and antenna gain;

[0060] The equivalent Earth radius is calculated based on the refractive index; the scattering angle, the lowest point height of the scatterer, and the highest point height of the scatterer are calculated based on the equivalent Earth radius, the antenna angle, and the great circle distance; the antenna dielectric coupling loss is calculated based on the antenna gain.

[0061] The link propagation loss is calculated using climate factors, non-uniformity coefficient, signal frequency, lowest point height of the scatterer, highest point height of the scatterer, and antenna medium coupling loss.

[0062] Specifically, such as Figure 3 As shown, the central node model of the tropospheric scattering communication network includes an antenna module a, a wireless receiver module rr, a wireless transmitter module rt, a physical access module MAC, an intermediate module interface, a network management module NetManager, a routing management module RouteManager, a service source data module src, and a reception statistics module sink.

[0063] The business source data module is used to generate data packets; optionally, the model adopts an on / off business mode, and relevant parameters for generating data packets can be set.

[0064] The routing management module is used to calculate the network route based on the destination address of the data packet and record the network route in the packet. If the destination address of the data packet is the current node, it is received and sent to the receiving statistics module for data statistics; if the destination address of the data packet is another node, the data packet is sent to the network management module.

[0065] The receiving statistics module collects information such as latency, data size, and power of data packets arriving at the node, and is used to destroy data packets that do not meet the requirements.

[0066] The network management module is used to send probe data packets to other nodes, and after receiving a reply confirmation data packet, establish node connection relationships and routing tables. When it receives a data packet sent by the routing management module, it confirms the transmitting port of the sending machine according to the routing information, records it in the packet, inserts it into the buffer queue, and sends it when the channel is idle. When it receives a data packet sent by the physical access module, if it is a data packet sent to this node or the data packet does not contain routing information, it sends it to the routing management module. If it is a data packet not sent to this node but contains routing information, it confirms the transmitting port of the forwarding machine according to the routing information, records it in the packet, inserts it into the buffer queue, and sends it when the channel is idle.

[0067] The intermediate module is used to send and receive data packets between the network management module and the physical access module; the physical access module is connected to the wireless receiver module and the wireless transmitter module respectively, receives data packets received by the antenna module through the wireless receiver module, and sends the data packets through the antenna module through the wireless transmitter module;

[0068] Optional, such as Figure 3 As shown, each central node includes four physical access modules. Each physical access module is connected to an antenna module along with a wireless receiver module and a wireless transmitter module. The antenna module, wireless receiver module, and wireless transmitter module are used to jointly simulate the wireless communication process, as shown below. Figure 2 The four antenna modules a_0~a_3, the physical access modules MAC_0~MAC_3, the wireless receiver modules rr_0~rr_3, and the wireless transmitter modules rt_0~rt_3 are shown in the figure.

[0069] According to the present invention, a tropospheric scattering communication network modeling method based on OPNET software is provided. The peripheral node model of the tropospheric scattering communication network includes an antenna module, a wireless receiver module, a wireless transmitter module, a physical access module, an intermediate module, a network management module, a routing management module, a service source data module, and a reception statistics module.

[0070] The network management module is used to receive data packets sent by the service source data module, calculate the receiver port and transmitter port of the central node corresponding to the current surrounding nodes, insert the data packets into the buffer sequence, and send them when the channel is idle.

[0071] The functions of the remaining modules are the same as those of the corresponding modules in the central node.

[0072] It should be noted that the data packet format settings in the scattering communication model are as follows: Figure 4 As shown:

[0073] Among them, FrameType is the protocol frame type. When the value is 1, it means that the data packet type is a probe data packet sent by the central node to the surrounding nodes; when the value is 2, it means that the data packet type is a reply acknowledgment data packet sent by the surrounding nodes to the central node; when the value is 3, it means that the data packet type is a data packet forwarded by the central node from another network, which requires the routing management module to calculate the route; when the value is 3, it means that the data packet type is a data packet carrying a data payload.

[0074] SrcNet is the subnet ID of the sending node, and Ta is the ID of the sending node, indicating the sender of the data packet;

[0075] DestNet is the subnet ID of the sending node, and Ra is the ID of the receiving node, indicating the recipient of the data packet;

[0076] SrcPort indicates the port number of the node that sent the data packet. During the forwarding process, the port number sent by the current forwarding center node will also be written. DestPort indicates the port number received by the next hop node.

[0077] rcvd power refers to the communication power of the scattering link;

[0078] Sequence is the sequence number of the data packet;

[0079] LifeTime is the valid lifespan of this data packet;

[0080] The Data field is used to store data content, and its actual length is variable.

[0081] The remaining part of the data packet format is a static routing table used to record packet forwarding;

[0082] SumHop is the total number of hops forwarded, and CurrentHop is the current hop count; T1-T16 represent the destination addresses of hops 1 to 16. If the destination node cannot be reached after more than 16 hops, the data packet is considered unreachable.

[0083] Furthermore, the chain-building protocol is divided into the chain-building protocol for communication between the central node and surrounding nodes, and the chain-building protocol for communication between the central nodes.

[0084] The connection establishment between the central node and surrounding nodes adopts a probe-response mechanism. The central node sends probe frames to the surrounding nodes of the network to be connected to. The surrounding nodes receive response frames and then register with the network management system to establish the connection.

[0085] Peripheral nodes are selected to connect to the central node of this subnet;

[0086] The central node sends probe packets to surrounding nodes and waits for responses from them.

[0087] After receiving the probe packet, the surrounding nodes respond to the central node;

[0088] Once the central node receives a response, it establishes a full-duplex link with the surrounding nodes, and the current round of probing ends.

[0089] Based on the established link information, the central node and surrounding nodes begin communication and data transmission, and wait for the next cycle of detection and response;

[0090] Furthermore, the establishment of links between central nodes adopts a probing mechanism. The central node sends probing frames to all other central nodes, and upon receiving them, the other central nodes register with the network to establish a one-way link.

[0091] Each of the central nodes sends probe frames to the other central nodes;

[0092] After receiving the probe frame from the current central node, other central nodes complete the establishment of a unidirectional link; after receiving the probe frame from other central nodes, the current central node completes the establishment of a unidirectional link; thus establishing a full-duplex link between the current central node and other central nodes.

[0093] Based on the established link information, the central nodes calculate routes, begin communication and data transmission, and wait for the next cycle of probes and responses.

[0094] Furthermore, after completing the network link establishment process, the network management system possesses all link information between the central nodes of the entire network. Based on this information, it calculates the shortest route to the target subnet using the shortest path algorithm, establishes a static routing table, and writes the route into the data packets; based on the link information, it calculates the shortest route for the data packets to reach the target subnet, such as... Figure 5 As shown, it includes:

[0095] Read the sending subnet information and receiving subnet information from the data packet, and initialize the shortest route information table; specifically, the shortest route information table is calculated starting from the sending subnet, and the table contains other subnets that the sending subnet can reach, as well as the shortest path to other subnets;

[0096] The sending subnet node is added to the shortest route information table. Then, based on the network management link information, other new nodes that the sending subnet node can reach are found, and the shortest path is updated. From these new nodes, the one with the smallest weight is selected and added to the shortest route information table. This process is repeated until no new nodes are added. Specifically, the link weight of each other node is calculated based on the link bandwidth, latency, and bit error rate, and the total weight of the shortest path to the subnet node is updated.

[0097] The shortest route to the target subnet is calculated based on the latest shortest route information table, and the shortest route is written into the data packet. Starting from the target subnet, the previous node of the target subnet is queried until the sending subnet node is found. After the query is completed, the static route information is written into the data packet and the data packet is sent. If the sending subnet cannot be found, the data packet is destroyed through the receiving statistics module.

[0098] In one embodiment, such as Figure 6 The diagram shows a network model of a tropospheric scattering communication network. In this network, there are a total of 6 tropospheric scattering trunk nodes, numbered node_0 to node_5. Tropospheric scattering communication links are established between these nodes, and the trunk nodes provide tropospheric scattering network access functionality to other users. Nodes 1 to 10 are the users accessing the network. Among them, nodes 8 and 4 are service center nodes. Node 8 forms a communication group with nodes 1, 2, 3, and 9, and node 4 forms a communication group with nodes 5, 6, 7, and 10.

[0099] In one embodiment, three different service intensities, namely, service intensity one, intensity two, and intensity three, are set. The specific settings depend on the voice, data, and video communication needs between user nodes, and the present invention does not limit them.

[0100] The voice service data interval follows a negative exponential distribution with a mean of 1 second, and the data size follows a negative exponential distribution with a mean of 1024 bits. Specifically, the working time and silence time of intensity 1 follow a negative exponential distribution with a mean of 120 seconds; the working time and silence time of intensity 2 follow a negative exponential distribution with a mean of 120 seconds; and the working time and silence time of intensity 3 follow a negative exponential distribution with a mean of 360 seconds and a negative exponential distribution with a mean of 840 seconds.

[0101] The data service data interval follows a negative exponential distribution with a mean of 1 second, and the working time is continuous. Among them, the data size of intensity 1 follows a negative exponential distribution with a mean of 34052 bits, the data size of intensity 2 follows a negative exponential distribution with a mean of 69904 bits, and the data size of intensity 3 follows a negative exponential distribution with a mean of 104856 bits.

[0102] The video service data interval follows a negative exponential distribution with a mean of 0.067s. The working time is continuous. The data size of intensity 1 follows a negative exponential distribution with a mean of 139 bits, the data size of intensity 2 follows a negative exponential distribution with a mean of 278 bits, and the data size of intensity 3 follows a negative exponential distribution with a mean of 417 bits.

[0103] The simulation results of network performance under different service intensities are analyzed.

[0104] Average end-to-end network latency under three different communication service intensities is as follows Figure 7 As shown in the simulation results, the average network latency for intensity 1 and intensity 2 fluctuates between 0.018s and 0.029s, with the average latency of each link around 0.02s. This indicates that the link timeliness is good, meeting the latency requirements of voice, video, and other services, and satisfying the communication task requirements. However, for service intensity 3, the end-to-end latency increases significantly and fluctuates considerably, ranging between 0.34s and 0.48s. Moreover, the end-to-end latency fluctuates over time, with an average latency of around 0.38s. At this intensity, the network can still support communication services, but the quality of voice and video communication is significantly affected.

[0105] Average network received traffic under three different communication service intensities, such as Figure 8 As shown in the figure. According to the simulation results, the average traffic volume of intensity 1 and intensity 2 is 10 million bits, and the average traffic volume of intensity 3 is 54 million bits; indicating that the scattering communication network can carry voice, data and video communication services.

[0106] Based on the above embodiments, the present invention realizes the establishment of a simulation model of tropospheric scattering communication network, providing an effective model for analyzing the performance of scattering communication network. By using the process model and node model of tropospheric scattering communication network, network models with different topologies can be formed, and through simulation, the average end-to-end latency, average traffic volume and other indicators of the network are obtained, providing a good experimental platform for the research on the networking and application modes of tropospheric scattering communication network.

[0107] The present invention also provides an electronic device, which may include a processor, a communications interface, a memory, and a communication bus, wherein the processor, the communications interface, and the memory communicate with each other through the communication bus. The processor can call logical instructions in the memory to execute the steps of the tropospheric scattering communication network modeling method provided by the above methods.

[0108] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0109] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, and when the program instructions are executed by a computer, the computer is able to perform the steps of the tropospheric scattering communication network modeling method provided by the above methods.

[0110] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the tropospheric scattering communication network modeling method provided by the above methods.

[0111] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0112] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0113] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for modeling tropospheric scattering communication networks based on OPNET software, characterized in that, include: A tropospheric scattering communication channel model is established, the link propagation loss is calculated based on the input parameters, and the signal reception power is calculated based on the transmit power and the link propagation loss. Based on each node of the tropospheric scattering communication network, a central node model and a peripheral node model of the tropospheric scattering communication network are established respectively. The central node model and the peripheral node model calculate the network route and determine the receiving node of the data packet according to the target address of the data packet. Establish a transmission protocol model for a tropospheric scattering communication network, including communication link establishment protocols between central nodes and surrounding nodes, as well as communication link establishment protocols between central nodes. Obtain all link information between all central nodes, and calculate the shortest route for data packets to reach the target subnet based on the link information. Based on the tropospheric scattering communication channel model, the central node model, the peripheral node model, and the tropospheric scattering communication network transmission protocol model, a tropospheric scattering communication network model is constructed, and the tropospheric scattering communication network is simulated. The communication and link establishment protocol between the central node and surrounding nodes includes: Each central node sends probe frames to the surrounding nodes of the protocol network to be accessed; After receiving the detection frame, the surrounding nodes send a response frame back to the central node; After receiving the response frame, the central node establishes a full-duplex link with the corresponding surrounding nodes. The central node-to-central node communication and connection establishment protocol includes: Each of the central nodes sends probe frames to the other central nodes; After receiving the probe frame from the current central node, other central nodes complete the establishment of a unidirectional link; after receiving the probe frame from other central nodes, the current central node completes the establishment of a unidirectional link; thus establishing a full-duplex link between the current central node and other central nodes.

2. The method for modeling tropospheric scattering communication networks based on OPNET software according to claim 1, characterized in that, Calculating the link propagation loss includes: The input parameters obtained include climate factors, non-uniformity coefficient, signal frequency, refractive index, antenna angle, great circle distance, and antenna gain; The equivalent Earth radius is calculated based on the refractive index; the scattering angle, the lowest point height of the scatterer, and the highest point height of the scatterer are calculated based on the equivalent Earth radius, the antenna angle, and the great circle distance; the antenna dielectric coupling loss is calculated based on the antenna gain. The link propagation loss is calculated using climate factors, non-uniformity coefficient, signal frequency, lowest point height of the scatterer, highest point height of the scatterer, and antenna medium coupling loss.

3. The method for modeling tropospheric scattering communication networks based on OPNET software according to claim 1, characterized in that, The central node model of the tropospheric scattering communication network includes an antenna module, a wireless receiver module, a wireless transmitter module, a physical access module, an intermediate module, a network management module, a routing management module, a service source data module, and a reception statistics module. The service source data module is used to generate data packets, and the routing management module is used to calculate network routes based on the destination address of the data packets and record the network routes in the packets. If the destination address of the data packets is the current node, the packets are received and sent to the receiving statistics module for data statistics. If the destination address of the data packets is another node, the packets are sent to the network management module. After receiving the data packet sent by the routing management module, the network management module confirms the transmitter port based on the routing information, records it in the data packet, inserts it into the buffer queue, and sends it to the intermediate module when the channel is idle. The intermediate module is used to send and receive data packets between the network management module and the physical access module; the physical access module is connected to the wireless receiver module and the wireless transmitter module respectively, receives data packets received by the antenna module through the wireless receiver module, and sends the data packets through the antenna module through the wireless transmitter module.

4. The method for modeling tropospheric scattering communication networks based on OPNET software according to claim 3, characterized in that, The physical access module is used to determine whether the current channel is idle, and to transmit data packets when the channel is idle; After receiving the data packet sent by the physical access module, if the destination address of the data packet is the current node or the data packet does not contain routing information, the network management module sends the data packet to the routing management module. If the destination address of the data packet is not that of this node and the data packet contains routing information, then the transmitter port for forwarding is determined according to the existing routing information, and recorded in the data packet, inserted into the buffer queue, and sent when the channel is idle.

5. A method for modeling tropospheric scattering communication networks based on OPNET software according to any one of claims 3 or 4, characterized in that, The peripheral node model of the tropospheric scattering communication network includes an antenna module, a wireless receiver module, a wireless transmitter module, a physical access module, an intermediate module, a network management module, a routing management module, a service source data module, and a reception statistics module. The network management module is used to receive data packets sent by the service source data module, calculate the receiver port and transmitter port of the central node corresponding to the current surrounding nodes, insert the data packets into the buffer sequence, and send them when the channel is idle.

6. The method for modeling tropospheric scattering communication networks based on OPNET software according to claim 1, characterized in that, Calculate the shortest route for data packets to reach the target subnet based on the link information, including: Read the sending subnet information and receiving subnet information from the data packet, and initialize the shortest route information table; The sending subnet node is added to the shortest route information table, other nodes that the subnet node can reach are calculated, and the link weight of each other node is calculated by weighting according to the link bandwidth, latency and bit error rate, and the total shortest path weight of the subnet node is updated. Select the node with the smallest total weight of the shortest path from the other reachable nodes and add it to the shortest route information table; The shortest route to the target subnet is calculated based on the latest shortest route information table, and the shortest route is written into the data packet; Starting from the target subnet, query the previous node of the target subnet until the sending subnet node is found. After the query is completed, write the static routing information into the data packet and send the data packet; if the sending subnet cannot be found, destroy the data packet.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method as described in any one of claims 1 to 6.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 6.

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