Low-frequency special data link communication system integrating central networking and ad hoc network

Abstract

The invention relates to the technical field of wireless communication, in particular to a low-frequency special data link communication system fusing a central networking and an ad hoc network. According to the technical scheme, the system comprises a central networking communication module, an ad hoc network communication module, a special data link module, a low-frequency communication optimization module, a clock synchronization module and a fault self-healing module. Through dynamic cooperation of the central networking and the ad hoc network, low-frequency signal special optimization, industry customization of a special data link and multi-module cooperation of precise clock synchronization and efficient fault self-healing, the problems of incomplete communication coverage, easy transmission interruption, poor industry adaptability and high information security risk in a complex environment are solved; the system is large in communication coverage range, stable in operation and accurately adaptive to different industry scenes, meanwhile, the real-time performance and safety of data transmission are guaranteed, the scene requirements of emergency rescue, industrial control monitoring, remote area communication guarantee and the like are met, and the stability and reliability of communication are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a low-frequency dedicated data link communication system that integrates central networking and self-organizing networking. Background Technology

[0002] The low-frequency data link communication system that integrates centralized networking and self-organizing networking is a wireless communication solution for complex scenarios such as emergency rescue and industrial control monitoring. Its core is to combine the centralized management and control of "central networking" (to achieve large-scale node access, bandwidth allocation and data aggregation) with the distributed resilience of "self-organizing networking" (to maintain local communication when the center fails). It also relies on the strong penetration and long propagation characteristics of low-frequency signals to build a dedicated data transmission link to meet the needs of communication coverage, stability and security in complex environments.

[0003] The existing technology has the following shortcomings: low integration of central networking and self-organizing network, mostly simple superposition, lack of collaborative units, slow triggering of self-organizing network and inefficient routing when the central network fails; insufficient low-frequency optimization, no compensation for terrain loss and distance error, resulting in many coverage blind spots; poor specialization, no industry-customized frame structure and encryption optimization, resulting in insufficient real-time performance and security; poor clock synchronization and fault self-healing adaptation, large clock deviation, and slow fault recovery.

[0004] In view of the above shortcomings, this invention proposes a low-frequency dedicated data link communication system that integrates centralized networking and self-organizing networking. This system achieves architecture adaptation through the collaboration of centralized networking and self-organizing network modules, improves coverage with the help of low-frequency communication optimization modules, enhances industry adaptability and security through dedicated data link modules, ensures clock accuracy with clock synchronization modules, and quickly handles faults with fault self-healing modules. It overcomes the shortcomings of existing technologies, and the comprehensive collaboration of each module effectively improves communication performance. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the background technology by proposing a low-frequency dedicated data link communication system that integrates centralized networking and self-organizing networking.

[0006] This application provides a low-frequency dedicated data link communication system that integrates centralized networking and self-organizing networking, including:

[0007] The central network communication module, as the main communication architecture, uses a centralized management and control mechanism to centrally manage multiple nodes, summarize node data according to priority, and monitor the coverage of communication signals.

[0008] The self-organizing network communication module, as a backup communication architecture, maintains local communication connectivity when the central network fails through distributed networking and dynamic routing mechanisms.

[0009] A dedicated data link module, through customized transmission protocols and encryption mechanisms, securely transmits critical information and optimizes the time delay generated during data interaction.

[0010] The low-frequency communication optimization module optimizes communication coverage and transmission by means of signal adaptation, loss compensation and distance calibration, combined with the characteristics of the low-frequency band.

[0011] The clock synchronization module adapts to different networking modes and controls the clock deviation range between nodes by providing a reference clock and performing deviation correction processing.

[0012] The fault self-healing module quickly handles node and link faults through real-time monitoring and fault determination logic.

[0013] Optionally, the central networking communication module includes a central control unit, a data aggregation unit, and a coverage monitoring unit:

[0014] The central control unit is responsible for node access control and bandwidth allocation. Node access must meet preset access conditions in terms of signal strength and bit error rate. The bandwidth allocation formula is as follows:

[0015]

[0016] in, For nodes The allocated bandwidth, The total system bandwidth, For nodes Bandwidth priority, The total number of connected nodes, not exceeding a preset upper limit;

[0017] The formula for calculating bandwidth priority is:

[0018]

[0019] in, , , The weighting coefficients are satisfied. + + =1, Prioritize business operations and assign corresponding preset values ​​based on industry business types. For nodes The current remaining energy, The maximum rated energy of the node. For nodes The link signal-to-noise ratio, This is the preset maximum signal-to-noise ratio reference value;

[0020] The data aggregation unit uses a priority scheduling mechanism to transmit data.

[0021] Coverage monitoring units monitor communication coverage blind spots over a large area.

[0022] Optionally, the data aggregation unit of the central networking communication module is specifically configured as follows: high-priority data is directly transmitted by the priority transmission queue within the unit; low-priority data is cached in a buffer of preset capacity within the unit, and is forcibly transferred to the transmission queue when the cache timeout reaches the preset duration.

[0023] The data aggregation period is the unit's preset period. The aggregated data is uploaded through a preset transmission protocol, and the upload packet loss rate does not exceed the unit's preset threshold.

[0024] Optionally, the self-organizing network communication module includes a distributed networking triggering unit, a dynamic routing unit, and a local connectivity maintenance unit:

[0025] The distributed networking triggering unit sets trigger conditions: when the signal strength of the central networking is detected to be lower than the unit's preset signal threshold, or when the interruption duration of the central networking reaches the unit's preset interruption duration, the self-organizing network is triggered to start; after triggering, the unit control node broadcasts a network request frame of a preset format within a preset time, and completes neighbor discovery by receiving network response frames from neighboring nodes; the dynamic routing unit calculates the optimal route and updates it periodically;

[0026] The local connectivity maintenance unit maintains the connectivity of the ad hoc network through the neighbor heartbeat mechanism.

[0027] Optionally, the dynamic routing unit of the ad hoc network communication module uses a weighted algorithm to calculate the routing weight, as shown in the formula:

[0028]

[0029] in, For nodes To the node Routing weights , , The weighting coefficients are satisfied. + + =1, For nodes With nodes The signal-to-noise ratio of the link between them For nodes With nodes physical distance, The maximum single jump distance is preset for each unit. For nodes The current load, Set a maximum load threshold for the unit.

[0030] Optionally, the dedicated data link module includes a protocol customization unit, an encrypted transmission unit, and an interaction optimization unit:

[0031] The protocol customization unit customizes dedicated data frame structures for different industry scenarios. The frame structure includes a frame header, a business type field, a data length field, a payload field, a checksum field, and a frame trailer.

[0032] The encrypted transmission unit employs a two-layer encryption mechanism to ensure the security of critical information.

[0033] The interaction optimization unit optimizes data interaction latency through a preset protocol.

[0034] Optionally, the encrypted transmission unit of the dedicated data link module is specifically configured as follows: key information is encrypted using a symmetric encryption algorithm, and the encrypted information is encapsulated into the Payload field.

[0035] The symmetric encryption key is distributed using an asymmetric encryption algorithm, and the key distribution period is a preset period for the unit.

[0036] After the information is decrypted, the unit verifies the data integrity through a preset verification algorithm to ensure that the information leakage rate does not exceed the unit's preset security threshold.

[0037] Optionally, the low-frequency communication optimization module includes a low-frequency signal adaptation unit, a penetration loss compensation unit, and a propagation distance calibration unit:

[0038] The low-frequency signal adaptation unit enables modulation and coding adaptation of low-frequency signals.

[0039] The penetration loss compensation unit calculates the penetration loss and the compensated transmit power using the following formula:

[0040]

[0041] in, For penetration loss, For the system operating frequency, For communication distance, This is the terrain attenuation coefficient;

[0042]

[0043] in, To compensate for the subsequent transmission power, The reference transmit power set for the unit, The loss compensation coefficient set for the unit. The maximum transmit power threshold set for the unit;

[0044] The propagation distance calibration unit calibrates the communication distance error.

[0045] Optionally, the clock synchronization module includes a reference clock unit, a deviation calculation unit, and a synchronization adjustment unit:

[0046] The reference clock unit provides a central node clock reference in the centralized networking mode and a cluster head clock reference in the self-organizing networking mode.

[0047] The deviation calculation unit uses a deviation correction algorithm to calculate the clock deviation between nodes. The formula is as follows:

[0048]

[0049] in, For nodes With nodes Clock deviation, For synchronization weighting coefficients, For the center reference deviation, For distributed deviation, The preset value for the delay error variance set for the unit. The speed of light is constant;

[0050] The synchronization adjustment unit dynamically adjusts the synchronization period based on the deviation calculation results to ensure that the clock deviation does not exceed the unit's preset deviation threshold.

[0051] Optionally, the fault self-healing module includes a fault detection unit and a self-healing execution unit:

[0052] The fault detection unit sets fault judgment logic: when the node bit error rate exceeds the unit's preset bit error rate threshold, it is judged as a node fault; when the link signal-to-noise ratio is lower than the unit's preset signal-to-noise ratio threshold and the duration reaches the unit's preset judgment duration, it is judged as a link fault.

[0053] The self-healing execution unit controls the switching of backup nodes for node failures, with the switching time not exceeding the unit's preset switching time; for link failures, it reconstructs the link based on the algorithm of the dynamic routing unit, with the reconstruction time not exceeding the unit's preset reconstruction time; the total recovery time for both types of failures does not exceed the unit's preset recovery time.

[0054] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0055] 1. By constructing a collaborative mechanism between the central network and the self-organizing network, the central network is relied upon to achieve large-scale node management and data aggregation on a daily basis. When the central architecture fails, the self-organizing network can be quickly started to maintain local communication. Combined with clock synchronization calibration and efficient fault self-healing function, communication interruption can be avoided, ensuring the continuous and reliable operation of the system in complex environments and meeting the long-term stable communication requirements.

[0056] 2. By specifically optimizing the characteristics of low-frequency signals, the signal transmission mode is adapted to complex terrains such as mountainous areas and underground areas, and the signal loss caused by the terrain is compensated for. This reduces attenuation and interference during signal transmission, narrows communication coverage blind spots, improves the stability of data transmission, and avoids signal interruption problems caused by terrain limitations.

[0057] 3. By customizing and adapting transmission protocols for industries such as emergency rescue and industrial control monitoring for dedicated data chain modules, and encrypting key information, we can meet the differentiated needs of different industries for real-time data transmission, while preventing the risk of information leakage. This not only achieves precise matching between the system and industry scenarios, but also balances practicality and security. Attached Figure Description

[0058] Figure 1 This is a block diagram illustrating the principle of a low-frequency dedicated data link communication system that integrates centralized networking and self-organizing networking. Detailed Implementation

[0059] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0060] Example

[0061] like Figure 1 As shown, the present invention proposes a low-frequency dedicated data link communication system that integrates centralized networking and self-organizing networking, comprising:

[0062] The central network communication module, as the main communication architecture of the system, undertakes three core functions: centralized management and control of multiple nodes, aggregation of node data according to priority, and monitoring of the coverage of communication signals.

[0063] Centralized management of multiple nodes: After powering on, the terminal node sends an access request containing its own ID, location, and remaining energy to the central node; the central node filters legitimate nodes based on the received signal strength and bit error rate, and allocates a unique communication identifier and resources such as bandwidth and transmission power to the legitimate nodes; at the same time, the central node periodically sends heartbeat frames and monitors the online status of the nodes. If a node fails to respond to the heartbeat for a continuous period of time, it is marked as offline and its resources are released.

[0064] Node data is aggregated according to priority: The central node prioritizes maintaining high-priority queues, such as vital signs data of trapped persons in emergency rescue, and then maintains ordinary queues, such as equipment status data. Terminal data frames carry service priority identifiers, and the central node distributes data to the corresponding queues accordingly. High-priority queues occupy transmission resources first, while ordinary queues transmit resources according to the first-in-first-out rule to avoid data backlog.

[0065] Monitoring the coverage of communication signals: The central node sends coverage detection frames to the entire frequency band every 10 seconds. The terminal nodes report their own location and received signal strength. The central node maps the data to an electronic map and draws a signal coverage heat map through interpolation algorithms. If the signal strength of a certain area is consistently below -85dBm, it is determined to be a coverage blind spot, triggering the loss compensation strategy of the low-frequency communication optimization module, such as increasing the transmission power or scheduling mobile nodes to enhance coverage.

[0066] The self-organizing network communication module, as a backup communication architecture, maintains local communication connectivity when the central network fails through distributed networking and dynamic routing mechanisms.

[0067] Failure detection and network triggering: The terminal node continuously monitors the signal quality and heartbeat frame frequency of the central node. If the signal strength of the central node is below -90dBm for 2 consecutive seconds and there is no heartbeat frame, the central network is determined to be in failure, and a self-organizing network invitation frame is immediately broadcast.

[0068] Distributed networking and cluster head election: Terminal nodes that receive the self-organizing network invitation frame exchange their own ID, location, and remaining energy through the neighbor discovery protocol. They then elect a cluster head node using a dual criterion of maximum remaining energy and optimal link quality. The cluster head node is responsible for local resource allocation and data forwarding.

[0069] Local connectivity maintenance: The self-organizing network adopts a mechanism of dynamic routing combined with neighbor heartbeat. Nodes build local routing tables through routing requests and responses. At the same time, nodes send heartbeat packets to their neighbors every 500 milliseconds. If a neighbor does not respond twice in a row, route rediscovery is triggered to find a reachable path again.

[0070] Dedicated data link modules, tailored to industry needs such as emergency rescue and industrial control monitoring, utilize customized transmission protocols and encryption mechanisms to securely transmit critical information and optimize time delays during data interaction.

[0071] Customized data transmission mechanism: Design a dedicated frame structure based on industry data characteristics. For example, the frame structure for emergency rescue scenarios combines a 16-bit node ID, an 8-bit priority identifier, 32-bit core data, and a 16-bit checksum to adapt to low frequency and narrow bandwidth. At the same time, define data priority and transmission time slot mapping rules, allocating more transmission time slots to high-priority data.

[0072] Encryption of critical information: A two-layer mechanism combining symmetric and asymmetric encryption is adopted. The central node generates a symmetric encryption key to encrypt business data, and then encrypts the symmetric key with the terminal public key used for asymmetric encryption to ensure secure key distribution. In self-organizing network mode, the cluster head node generates and distributes the symmetric key.

[0073] Interaction latency optimization: A sliding window combined with a priority pre-scheduling mechanism is introduced. The sending end uses a dynamic sliding window to send multiple frames continuously without waiting for acknowledgment. The receiving end sets up a fast acknowledgment channel for high-priority data and replies with acknowledgment frames first, thereby reducing interaction latency.

[0074] The low-frequency communication optimization module, based on the characteristics of strong diffraction and good penetration but narrow bandwidth in the 100kHz-500kHz low-frequency band, improves communication coverage and transmission stability in complex terrain:

[0075] Modulation and coding adaptation: A combination of binary frequency shift keying and convolutional codes is selected. Binary frequency shift keying has good noise immunity and is suitable for narrow bandwidth, while convolutional codes reduce bit errors through forward error correction.

[0076] Penetration loss compensation: Establish terrain, distance and loss models, calculate signal penetration loss in real time, and dynamically adjust the transmission power to compensate for attenuation based on the loss value;

[0077] Propagation distance calibration: Combining the BeiDou positioning and signal attenuation model, a calibration model for positioning distance and actual effective communication distance is trained. When making node routing decisions, a more reliable link is selected based on the calibrated distance to optimize transmission stability.

[0078] The clock synchronization module is compatible with both centralized and self-organizing network modes. By providing a reference clock and performing deviation correction, it controls the clock deviation range between nodes, ensuring data timing consistency.

[0079] Reference clock selection: The central network uses the GPS disciplined clock of the central node as the reference, while the self-organizing network uses the Beidou time synchronization module of the cluster head node as the local reference;

[0080] Clock skew calculation: A two-way timestamp exchange algorithm is used. Node A sends a synchronization request frame with a timestamp to Node B. Node B replies with a synchronization response frame with its own timestamp. Node A calculates the clock skew based on the sending and receiving timestamps and after eliminating the propagation delay.

[0081] Deviation Feedback and Correction: Nodes adjust their local clocks based on deviations and provide feedback, dynamically adjusting the synchronization period to accelerate synchronization convergence;

[0082] The fault self-healing module quickly handles node and link failures through real-time monitoring and fault determination logic.

[0083] Fault detection phase:

[0084] Node failure: determined by receiving bit error rate and heartbeat detection;

[0085] Link failure: determined by signal strength and route reachability;

[0086] Self-healing execution phase:

[0087] Node failure: Triggers standby node switchover. The neighbors of the failed node automatically forward data to the pre-configured standby node, and the standby node quickly connects to the network to take over communication.

[0088] Link failure: Triggers route reconstruction, the node initiates local route discovery, searches for new paths and updates the routing table.

[0089] Furthermore, the specific operation steps for each unit in the central network communication module are as follows:

[0090] The central control unit is responsible for node access control and bandwidth allocation.

[0091] Node access control includes:

[0092] Terminal initiates request: Terminal node After power-on initialization, an access request frame is sent to the central node. The frame contains basic information such as the node's unique ID, current location, and service type.

[0093] Central detection conditions: After receiving a request, the central node detects the nodes in real time. Signal strength and bit error rate;

[0094] Access Decision: If the signal strength is greater than or equal to the preset access signal strength threshold, and the bit error rate is less than or equal to the preset access bit error rate threshold, then the node is allowed to access the network. If the connection is denied, the node will be notified of the reason for the denial, which may include weak signal and high bit error rate.

[0095] The specific steps for bandwidth allocation are as follows:

[0096] The first step is to calculate the nodes. Bandwidth priority ;

[0097] The second step is to calculate the nodes. allocated bandwidth ;

[0098] Furthermore, for the data aggregation unit, in order to satisfy the priority scheduling mechanism for data transmission, the following operations are performed:

[0099] The first step is data classification and caching. After receiving data from each node, the central node, based on the service priority identifier of the data frame, compares it with the data in the central control unit. Correspondingly, the data is divided into two categories:

[0100] The first category is high-priority data, such as emergency rescue vital signs data, which is stored in a high-priority cache queue and has preemptive scheduling authority.

[0101] The second category is: ordinary priority data, such as device status data, which is stored in an ordinary cache queue and cached using a first-in-first-out rule;

[0102] The second step is priority-based transmission scheduling. The central node scheduler forwards data according to the rule of higher priority first, and for data of the same priority, it is first-in, first-out. The specific details are as follows:

[0103] If there is data in the high-priority queue, prioritize the transmission of high-priority data and pause the scheduling of ordinary queues until the high-priority queue has no data or a scheduling gap occurs.

[0104] If the high-priority queue is empty, schedule the data from the ordinary queue and forward the data in the first-in-first-out order.

[0105] Secondly, regarding the coverage monitoring unit, its purpose is to monitor communication coverage blind spots over a large area. The specific steps are as follows:

[0106] The first step is to send coverage detection signals. The central node broadcasts coverage detection frames to the entire frequency band every 10 seconds. The frames contain information such as the location of the central node and the transmission power.

[0107] The second step is terminal node feedback. After receiving the coverage detection frame, the terminal node connected to the central network measures its own received signal strength and location information, and returns a coverage feedback frame to the central node. This feedback frame contains the node ID, location and received signal strength.

[0108] The third step, blind spot analysis and marking, involves performing the following operations after all coverage feedback frames are collected at the central node:

[0109] Regional gridding: Dividing a large area into several small squares according to latitude and longitude;

[0110] Blind zone determination: If there is no terminal node feedback in a certain grid, or the strength of the received signal feedback is consistently lower than the blind zone determination threshold, which is set to -90dBm, then the grid is determined to be a communication coverage blind zone.

[0111] Visualization and optimization triggering: The central node marks blind spots on the electronic map and links with the low-frequency communication optimization module to increase the transmission power of the area and schedule mobile nodes to enhance coverage.

[0112] This invention provides a detailed description of the ad hoc network communication module, and the specific operation steps of each unit of the ad hoc network communication module are as follows:

[0113] Firstly, the distributed networking triggering unit is involved, as detailed below:

[0114] The first step is trigger condition monitoring: the terminal node continuously monitors the communication status of the central network, focusing on two key indicators:

[0115] The first indicator is: the signal strength of the central network. The signal strength of the central node is detected in real time and compared with the preset signal threshold of the unit, which is set to −85 dBm.

[0116] The second metric is: Central network interruption duration. This involves calculating the duration of signal interruption at the central node and comparing it to the preset interruption duration for each unit. When the signal strength is less than the preset threshold or the interruption duration is greater than or equal to the preset interruption duration, the self-organizing network is triggered.

[0117] The second step involves broadcasting a network formation request frame: After the self-network formation is triggered, the uncontrolled node broadcasts a network formation request frame of a preset format to the surrounding area at a preset time. The frame contains key information such as the unique ID of the sending node, location information, and remaining energy.

[0118] The third step is neighbor discovery and response: After receiving the network request frame, the surrounding terminal nodes reply with a network response frame within a preset time. The node that initiated the request collects the response frames of all neighbors, generates a neighbor list, and completes the initial neighbor discovery.

[0119] Secondly, the dynamic routing unit is involved, as detailed below:

[0120] The first step is real-time parameter collection: for calculating route weights. The following parameters need to be collected:

[0121] Parameter 1: Link signal-to-noise ratio (SNR), obtained in real time through the node's link quality detection module. With nodes The signal-to-noise ratio of the link between them;

[0122] Parameter 2: Physical distance, obtained through the BeiDou positioning module. With nodes Calculate the physical distance between the two using their latitude and longitude.

[0123] Parameter 3: Node load, statistics of nodes The current amount of data processed or the communication bandwidth used reflects the node load.

[0124] Parameter 4: Preset reference values. The system pre-configures the maximum signal-to-noise ratio reference value, maximum single-hop distance, maximum load threshold, and weighting coefficients. , , It should meet + + =1, can be adjusted according to the scenario, such as in an emergency scenario. Higher weight is given to prioritize ensuring link quality;

[0125] The second step is to calculate the route weight by substituting the collected parameters into the weighted algorithm formula:

[0126]

[0127] compute nodes To the node Routing weight The value range is controlled between 0 and 1, and the larger the value, the better the routing;

[0128] The third step is optimal route selection. Within the unit's preset route update cycle, the nodes are... Calculate the routing weight for each of the neighboring nodes. The link with the highest weight is selected as the optimal route;

[0129] The fourth step is periodic route updates. Following the preset route update cycle, the process of parameter collection, weight calculation, and optimal route selection is repeated to achieve dynamic route adjustment and adapt to changes in network topology.

[0130] Finally, regarding the locally connected maintenance unit, the specific steps are as follows:

[0131] Step 1: Establishing the heartbeat mechanism. Nodes within the ad hoc network send heartbeat frames to each other according to a preset heartbeat cycle. These frames contain the operating status of the sending node, such as its working status and remaining energy level.

[0132] Step 2: Real-time connectivity monitoring. Nodes determine whether neighboring nodes are online and whether the link is connected by receiving heartbeat frames from their neighbors. If a node does not receive a neighbor's heartbeat frame for three consecutive times, it is determined that the neighbor is disconnected or the link is interrupted.

[0133] Step 3: Connectivity restoration is triggered. When a neighbor is detected to be disconnected or the link is interrupted, the routing update process of the dynamic routing unit is immediately triggered to recalculate and select the optimal route to maintain the communication connectivity of the ad hoc network.

[0134] This invention provides a detailed description of a dedicated data link module, and the specific operation steps of each unit of the dedicated data link module are as follows:

[0135] Firstly, the protocol customization unit is involved: This unit, targeting specific industry scenarios such as emergency rescue and industrial control monitoring, identifies core transmission requirements such as data types, transmission frequencies, and priorities, and customizes dedicated data frame structures. The specific operation is as follows:

[0136] Frame header: Sets the synchronization word so that the receiving end can quickly identify the start position of the frame and achieve frame synchronization;

[0137] Business type field: Defines a business identifier using 1 byte, used to distinguish data types and priorities;

[0138] Data length field: Use 2 bytes to indicate the number of bytes in the Payload field, so that the receiving end knows the range of data to be read;

[0139] Payload field: As a carrier of key information, its length can be customized as needed, for example, to include latitude and longitude, timestamp-related data in emergency scenarios;

[0140] Checksum field: A checksum is generated using a preset CRC16 checksum algorithm to initially verify the integrity of data transmission;

[0141] Frame end: Sets an end marker to help the receiver determine whether the frame has been received completely;

[0142] Once the dedicated data frame structure is customized, it enters the encrypted transmission unit. The main function of this unit is to ensure the security of critical information through double-layer encryption. The specific steps are as follows:

[0143] First, symmetric encryption is used to encrypt key information. Symmetric encryption algorithms such as AES-256 are selected to encrypt core key information in the payload, such as the location of trapped people in emergency rescue and control commands of industrial control systems. The encrypted key information is then encapsulated into the payload field of the data frame and prepared for transmission.

[0144] Secondly, the asymmetric encryption distribution of the symmetric key generates a key for symmetric encryption. Using asymmetric encryption algorithms such as RSA, the symmetric key is encrypted using the public key of the receiving node. According to the preset cycle of the unit, the encrypted symmetric key is distributed to the corresponding receiving node to ensure the secure transmission and regular updating of the key.

[0145] Finally, for data decryption and integrity verification, the receiving node uses its own private key to decrypt the received encryption symmetric key, obtains the symmetric key used to decrypt the payload, and uses the decrypted symmetric key to decrypt the encrypted information in the payload field of the data frame, restores the key information, and verifies the decrypted data through a preset verification algorithm consistent with that of the sending end to ensure that the data transmission has not been tampered with and that the information leakage rate does not exceed the preset security threshold of the unit.

[0146] Once the encrypted transmission is complete, the system enters the preset protocol optimization stage to reduce data interaction latency. This stage is handled by the interaction optimization unit, and the specific steps are as follows:

[0147] First, based on the industry's low-latency requirements, configure the preset protocol parameters as follows:

[0148] The first step is to adjust the transmission timing: shorten the data sending interval, optimize the ACK response timing, and use delayed acknowledgment to reduce the number of interactions;

[0149] The second step is to optimize the transmission window: adopt a dynamic sliding window mechanism to adjust the window size according to the real-time network status, for example, to increase the throughput when the network is good.

[0150] The third step is to define priority scheduling: configure priority transmission permissions for high-priority services to ensure low-latency transmission of critical data;

[0151] Finally, we enter the protocol-driven data interaction stage. During data transmission, the sending and receiving ends work together to execute data transmission and reception logic according to the pre-configured protocol, reducing redundant waiting and invalid operations, thereby reducing data interaction latency and improving transmission efficiency.

[0152] This invention provides a detailed description of a low-frequency communication optimization module, and the specific operation steps of each unit of the low-frequency communication optimization module are as follows:

[0153] The purpose of the low-frequency signal adaptation unit is to achieve modulation and coding adaptation of low-frequency signals. The specific steps are as follows:

[0154] Determine the operating frequency and scenario: Based on communication requirements, such as mountainous and underground environments, select the system operating frequency from the unit's preset low-frequency range. ;

[0155] Signal modulation adaptation: Select a modulation method that is suitable for low frequency and narrow bandwidth and has strong anti-interference, and modulate the digital signal to be transmitted into an analog carrier signal that is adapted to the low frequency channel;

[0156] Encoding adaptation enhances anti-interference: The error correction coding technology based on convolutional codes is adopted to add redundant coding to the modulated signal, which improves the anti-interference and error correction capabilities of the signal when transmitting in low-frequency channels, making the signal more adaptable to the characteristics of low-frequency channels.

[0157] The penetration loss compensation unit is used to calculate the penetration loss and the compensated transmit power. The specific steps are as follows:

[0158] Step 1: Collect key parameters. This step consists of three parts, as follows:

[0159] System operating frequency : Obtain the current operating frequency from the low-frequency signal adapter unit;

[0160] Communication distance The distance between communication nodes is obtained through BeiDou positioning modules or signal delay measurement.

[0161] Terrain attenuation coefficient Based on the actual terrain type, such as plains, mountains, and underground, the corresponding terrain attenuation coefficient preset by the unit is invoked;

[0162] Step 2: Calculate the penetration loss Substitute the collected parameters into the penetration loss formula to calculate the signal penetration loss in the current scenario;

[0163] Step 3: Calculate the compensated transmit power The details are as follows:

[0164] Determine the preset parameters of the unit: reference transmit power Loss compensation coefficient Maximum transmit power threshold ;

[0165] Substitute into the compensation power formula: first calculate , and then with The smaller value is selected as the final compensated transmit power.

[0166] Step 4: Adjust the transmission power, set the power of the transmission module to [value missing]. Power compensation is used to offset penetration loss and ensure signal transmission quality.

[0167] The purpose of the propagation distance calibration unit is to calibrate the communication distance error. The specific steps are as follows:

[0168] Step 1: Obtain the raw communication distance. The raw communication distance between nodes is obtained through the BeiDou positioning system or signal round-trip time measurement.

[0169] Step 2: Analyze the sources of low-frequency propagation error. Because the speed and attenuation of low-frequency signals differ when they propagate in different media, such as air, soil, and rocks, there is a deviation between the original measured distance and the actual effective communication distance.

[0170] Step 3: Apply the calibration model to correct the distance. Taking into account factors such as terrain and frequency, call the unit's preset calibration model to correct the original distance. Corrections can be made, for example, in mountainous scenes where low-frequency signal diffraction is significant, which can be addressed using formulas. ,in The terrain-related calibration coefficients are used to calculate the calibrated communication distance. ;

[0171] Step 4: Adjust the calibrated communication distance This is passed to modules that rely on distance calculations to improve the accuracy of distance-related functions.

[0172] This invention also relates to a clock synchronization module, which can adapt to different networking modes and control the clock deviation range between nodes. Analysis is then performed on the various units within this module.

[0173] The function of the reference clock unit is to provide a clock reference, and the steps are as follows:

[0174] Step 1: Determine the network topology. The system first determines whether the current working mode is a central network topology or a self-organizing network topology.

[0175] Step 2: Clock reference in central networking mode. In central networking mode, the reference clock unit is provided by the high-precision clock source of the central node, which serves as the core reference for clock synchronization of the entire system.

[0176] Step 3: Clock reference in self-organizing network mode. If in self-organizing network mode, the cluster head node is first determined through cluster head election, and then the local high-precision clock of the cluster head node provides the cluster head clock reference as a local clock reference for the self-organizing network.

[0177] Next, we analyze the deviation calculation unit, whose function is to calculate the clock deviation between nodes. At this point, we need to substitute the parameters into the formula:

[0178]

[0179] The steps are as follows: First, obtain the synchronization weight coefficients. Depending on the network topology (centralized network or self-organizing network), the corresponding weights preset by the unit are invoked, for example, in a centralized network. =0.8, self-organizing network =0.2;

[0180] Recalculate the center reference deviation For centralized networking, compare the clock of the central node with that of the node in the reference clock unit. / The local clock is used to obtain the center reference deviation, which is the difference between the center clock and the local clock; for ad hoc networks, the auxiliary reference deviation is obtained by comparing the cluster head clock with the local clock.

[0181] Calculate distributed deviation by exchanging bidirectional timestamps between nodes. ,node Send a synchronization request frame, node Receive frames, record them, and reply with synchronization response frames; node Frame reception records are used to deduce round-trip delay and clock skew, thus obtaining distributed skew. ;

[0182] In calculation At this time, it is necessary to first obtain the variance of the delay error, the speed of light, and the distance between nodes:

[0183] When obtaining the variance of the delay error and the speed of light The preset delay error variance for the unit, the speed of light Can be set to ;

[0184] When obtaining the distance between nodes, the BeiDou positioning nodes are used. , Location, calculate physical distance ;

[0185] Finally, substitute the parameters into the formula to calculate the deviation. Substitute all parameters into the formula to obtain the node. and Clock deviation;

[0186] The function of the synchronization adjustment unit is to dynamically adjust the synchronization period. The specific steps are as follows:

[0187] Step 1: Put The deviation is compared with the preset deviation threshold of the unit to complete the deviation exceeding the limit judgment;

[0188] Step 2: Adjust the synchronization period. If the deviation is less than or equal to the threshold, maintain the current synchronization period. If the deviation is greater than the threshold, shorten the synchronization period and speed up the calibration until the deviation returns to within the threshold, then restore the original period.

[0189] Step 3: Based on the deviation results, adjust the local clock of the node by fast or slow adjustment, and adjust the crystal oscillator counting frequency to ensure that the clock deviation does not exceed the preset threshold.

[0190] This invention also relates to a fault self-healing module, which includes a fault detection unit and a self-healing execution unit, and the specific steps are as follows:

[0191] First, we analyze how the fault detection unit determines node and link faults, which mainly involves three steps:

[0192] The first step is to preset the fault judgment threshold, the bit error threshold, and the signal-to-noise ratio threshold and judgment time, which are used to judge node faults;

[0193] The second step is to monitor the status of nodes and links in real time. When monitoring the node bit error rate, the number of bit errors in the data transmitted and received by each node is continuously counted / the total number of bits, the real-time bit error rate is calculated, and it is compared with the bit error threshold. When monitoring the link signal-to-noise ratio, the signal-to-noise ratio of each link is continuously collected. If the signal-to-noise ratio is lower than the signal-to-noise ratio threshold, a timer is started to monitor whether the duration reaches the preset time.

[0194] The third step is to determine the type of fault. If the node bit error rate is greater than the bit error threshold, it is determined to be a node fault; if the link signal-to-noise ratio is less than the signal-to-noise ratio threshold and the duration is greater than or equal to the preset judgment duration, it is determined to be a link fault.

[0195] When analyzing how the self-healing execution unit performs fault recovery, it is necessary to conduct a specific analysis in two scenarios, as follows:

[0196] Scenario 1: Backup node switchover in case of node failure. The specific steps are as follows:

[0197] Step 1: During system deployment, pre-configure at least one standby node for each primary node. The standby node should have the same hardware and functions as the primary node and be in a ready state.

[0198] Step 2: After determining that a node is faulty, immediately isolate the faulty node from the central network or self-organizing network, stop forwarding data to it, and complete the isolation of the faulty node.

[0199] Step 3: Send a switchover command to the pre-configured standby node. After receiving the command, the standby node starts the switchover process and triggers the standby switchover.

[0200] Step 4: The backup node quickly completes network access, such as obtaining communication identifiers and bandwidth resources, adding it to the routing table in self-organizing network mode, and completing the switching access with a switching time ≤ the unit's preset switching time.

[0201] Scenario 2: Dynamic route reconstruction in case of link failure. The specific steps are as follows:

[0202] Step 1: Identify the nodes at both ends of the faulty link and locate the faulty link;

[0203] Step 2: Invoke the weighted algorithm of the ad hoc network dynamic routing unit to start the link reconstruction process, which will trigger route reconstruction;

[0204] Step 3: Based on the dynamic routing algorithm, reselect the optimal communication link for nodes A and B, ensuring that the reconstruction time is less than or equal to the preset reconstruction time of the unit, and establish the new link;

[0205] Step 4: After the new link is established, restore data transmission on the original link to ensure communication continuity and complete the data transmission restoration.

[0206] The total recovery time for both of the above fault types does not exceed the unit's preset recovery time. The total recovery time refers to the time from fault detection to complete communication recovery.

[0207] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking, characterized in that, include: The central network communication module, as the main communication architecture, uses a centralized management and control mechanism to centrally manage multiple nodes, summarize node data according to priority, and monitor the coverage of communication signals. The self-organizing network communication module, as a backup communication architecture, maintains local communication connectivity when the central network fails through distributed networking and dynamic routing mechanisms. A dedicated data link module, through customized transmission protocols and encryption mechanisms, securely transmits critical information and optimizes the time delay generated during data interaction. The low-frequency communication optimization module optimizes communication coverage and transmission by means of signal adaptation, loss compensation and distance calibration, combined with the characteristics of the low-frequency band. The clock synchronization module adapts to different networking modes and controls the clock deviation range between nodes by providing a reference clock and performing deviation correction processing. The fault self-healing module quickly handles node and link faults through real-time monitoring and fault determination logic.

2. The low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The central networking communication module includes a central control unit, a data aggregation unit, and a coverage monitoring unit: The central control unit is responsible for node access control and bandwidth allocation. Node access must meet preset access conditions in terms of signal strength and bit error rate. The bandwidth allocation formula is as follows: ； in, For nodes The allocated bandwidth, The total system bandwidth, For nodes Bandwidth priority, The total number of connected nodes, not exceeding a preset upper limit; The formula for calculating bandwidth priority is: ； in, , , The weighting coefficients are satisfied. + + =1, Prioritize business operations and assign corresponding preset values ​​based on industry business types. For nodes The current remaining energy, The maximum rated energy of the node. For nodes The link signal-to-noise ratio, This is the preset maximum signal-to-noise ratio reference value; The data aggregation unit uses a priority scheduling mechanism to transmit data. Coverage monitoring units monitor communication coverage blind spots over a large area.

3. The low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 2, characterized in that, The data aggregation unit of the central networking communication module is specifically configured as follows: high-priority data is directly transmitted by the priority sending queue within the unit; low-priority data is cached in a buffer of preset capacity within the unit, and is forcibly transferred to the sending queue when the cache timeout reaches the preset duration. The data aggregation period is the unit's preset period. The aggregated data is uploaded through a preset transmission protocol, and the upload packet loss rate does not exceed the unit's preset threshold.

4. The low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The self-organizing network communication module includes a distributed networking triggering unit, a dynamic routing unit, and a local connectivity maintenance unit. The distributed networking triggering unit sets trigger conditions: when the signal strength of the central networking is detected to be lower than the unit's preset signal threshold, or when the interruption duration of the central networking reaches the unit's preset interruption duration, the self-organizing network is triggered to start; after triggering, the unit control node broadcasts a "network request" frame in a preset format within a preset time, and completes neighbor discovery by receiving "network response" frames from neighboring nodes; the dynamic routing unit calculates the optimal route and updates it periodically; The local connectivity maintenance unit maintains the connectivity of the ad hoc network through the neighbor heartbeat mechanism.

5. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 4, characterized in that, The dynamic routing unit of the self-organizing network communication module uses a weighted algorithm to calculate the routing weight, as shown in the formula: ； in, For nodes To the node Routing weights , , The weighting coefficients are and satisfy the following conditions: + + =1, For nodes With nodes The signal-to-noise ratio of the link between them For nodes With nodes physical distance, The maximum single jump distance is preset for each unit. For nodes The current load, The maximum load threshold is preset for the unit, and the routing update cycle of the unit is set to a preset cycle. Each time an update is performed, the link with the highest weight is selected as the optimal route.

6. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The dedicated data link module includes a protocol customization unit, an encrypted transmission unit, and an interaction optimization unit: The protocol customization unit customizes dedicated data frame structures for different industry scenarios. The frame structure includes a frame header, a business type field, a data length field, a payload field, a checksum field, and a frame trailer. The encrypted transmission unit employs a two-layer encryption mechanism to ensure the security of critical information. The interaction optimization unit optimizes data interaction latency through a preset protocol.

7. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 6, characterized in that, The encrypted transmission unit of the dedicated data chain module is specifically configured as follows: key information is encrypted using a symmetric encryption algorithm, and the encrypted information is encapsulated into the Payload field. The symmetric encryption key is distributed using an asymmetric encryption algorithm, and the key distribution period is a preset period for the unit. After the information is decrypted, the unit verifies the data integrity through a preset verification algorithm to ensure that the information leakage rate does not exceed the unit's preset security threshold.

8. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The low-frequency communication optimization module includes a low-frequency signal adaptation unit, a penetration loss compensation unit, and a propagation distance calibration unit. The low-frequency signal adaptation unit enables modulation and coding adaptation of low-frequency signals. The penetration loss compensation unit calculates the penetration loss and the compensated transmit power using the following formula: ； in, For penetration loss, For the system operating frequency, For communication distance, This is the terrain attenuation coefficient; ； in, To compensate for the subsequent transmission power, The reference transmit power set for the unit, The loss compensation coefficient set for the unit. The maximum transmit power threshold set for the unit; The propagation distance calibration unit calibrates the communication distance error.

9. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The clock synchronization module includes a reference clock unit, a deviation calculation unit, and a synchronization adjustment unit: The reference clock unit provides a central node clock reference in the centralized networking mode and a cluster head clock reference in the self-organizing networking mode. The deviation calculation unit uses a deviation correction algorithm to calculate the clock deviation between nodes. The formula is as follows: ； in, For nodes With nodes Clock deviation, For synchronization weighting coefficients, For the center reference deviation, For distributed deviation, The preset value for the delay error variance set for the unit. The speed of light is constant; The synchronization adjustment unit dynamically adjusts the synchronization period based on the deviation calculation results to ensure that the clock deviation does not exceed the unit's preset deviation threshold.

10. A low-frequency dedicated data link communication system integrating centralized networking and self-organizing networking according to claim 1, characterized in that, The fault self-healing module includes a fault detection unit and a self-healing execution unit: The fault detection unit sets fault judgment logic: when the node bit error rate exceeds the unit's preset bit error rate threshold, it is judged as a node fault; when the link signal-to-noise ratio is lower than the unit's preset signal-to-noise ratio threshold and the duration reaches the unit's preset judgment duration, it is judged as a link fault. The self-healing execution unit controls the switching of backup nodes for node failures, with the switching time not exceeding the unit's preset switching time; for link failures, it reconstructs the link based on the algorithm of the dynamic routing unit, with the reconstruction time not exceeding the unit's preset reconstruction time; the total recovery time for both types of failures does not exceed the unit's preset recovery time.

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