Fire-fighting outdoor rescue assistance method and system based on multiple communication modes

Abstract

The application provides a fire-fighting outdoor rescue auxiliary method and system based on multiple communication modes, and relates to the technical field of fire-fighting rescue and emergency communication. The method obtains the position of personnel by fusing Beidou, UWB, LoRa and mobile terminal positioning, and constructs an electronic fence for safety monitoring accordingly. Once it is found that the personnel crosses the border or drops the line, the system automatically triggers an alarm, and intelligently switches the available links such as LoRa ad hoc network, Beidou short message or public network to transmit the alarm information and position data, so as to ensure the communication reliability under the condition of no public network signal. At the same time, the system links the trajectory library to provide historical trajectory reference for the command personnel and rescue personnel to assist rescue decision. The application effectively improves the positioning stability, risk identification accuracy and communication continuity in complex environment, and significantly enhances the efficiency and safety of outdoor rescue.

Description

Technical Field

[0001] This invention relates to the field of fire rescue and emergency communication technology, specifically to a fire outdoor rescue auxiliary method and system based on multiple communication methods. Background Technology

[0002] With the increasing popularity of outdoor sports and the rise of emergencies in complex environments, fire rescue missions are becoming more frequent and diverse. Existing rescue equipment and auxiliary tools are mostly single-function; for example, ordinary map navigation applications can provide basic route guidance, but they struggle to meet the requirements for high-precision positioning and real-time route planning in complex environments such as mountains and forests. Some systems rely on mobile communication networks, which often experience communication interruptions in remote areas or disaster environments, leading to a lack of continuity and reliability in rescue missions. To compensate for network deficiencies, some applications offer offline map or trajectory recording functions, but these functions are relatively fragmented and cannot provide systematic support during rescue operations.

[0003] Therefore, while existing technologies have improved rescue efficiency to some extent, they still have significant limitations in complex real-world environments. First, communication in extreme environments relies heavily on public networks. If base stations are damaged or network coverage is lost, information transmission between rescue personnel and between rescuers and the command center can easily be interrupted, severely impacting rescue progress and safety. Second, path acquisition and personnel status monitoring in complex terrain are not precise enough. Conventional positioning methods are prone to errors in complex areas, making it difficult for rescue teams to accurately determine the precise location and movement trajectory of personnel, resulting in positioning distortion and unreasonable path planning, increasing rescue risks and time costs. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a fire-fighting outdoor rescue assistance method and system based on multiple communication methods to solve the aforementioned technical problems.

[0005] In a first aspect, the present invention provides a fire-fighting outdoor rescue assistance method based on multiple communication methods, comprising: The location information of rescue team members is obtained by combining BeiDou satellite positioning and UWB relative positioning, and then fused with mobile terminal positioning data. Among them, LoRa self-organizing network is used as one of the communication links to transmit the location information and alarm events. Based on the location information, an electronic fence safety boundary is constructed to monitor the activity range of rescue personnel. When it is detected that a team member has exceeded the safety boundary or has lost connection due to communication interruption, an alarm event is generated and an emergency call process is initiated. In the emergency call process, the communication link detection module is invoked to detect the BeiDou short message link and the LoRa self-organizing network link to ensure that the alarm event is transmitted through one of the BeiDou short message link and the LoRa self-organizing network link when there is no public network signal. When the LoRa self-organizing network link is detected to be available, the alarm event is forwarded using the LoRa self-organizing network. When the LoRa self-organizing network link is detected to be unavailable, the system switches to the BeiDou short message link, compresses and encodes the alarm event and location information, and then transmits it to the rescue command terminal. During the transmission of alarm events, the communication link detection module simultaneously monitors the availability of 4G / 5G links. When the 4G / 5G links are restored, while maintaining the monitoring of BeiDou and LoRa self-organizing network links, the link with the best current transmission latency is selected to complete the subsequent information transmission. While transmitting alarm events, the trajectory library is invoked to retrieve historical trajectory data related to the trigger location, and the trajectory data and alarm information are pushed to the rescue command terminal together to assist in generating rescue dispatch routes.

[0006] As a further technical solution, the positioning fusion adopts continuous periodic trend comparison when comparing BeiDou positioning, UWB relative positioning, and mobile terminal positioning. When the calculation result of a certain positioning source gradually deviates from the overall trend over several consecutive periods, its weight is not immediately reduced to the minimum, but is reduced in stages in a progressive manner. The reduction range of each stage is determined by the deviation range of the previous period. For example, when BeiDou positioning deviates from the overall trend by more than five meters in three consecutive samplings, the system will gradually reduce its weight from the normal value to half, and then continue to observe in subsequent periods. If the positioning source gradually recovers to be consistent with the overall trend in subsequent periods, its weight is also restored in stages in a progressive manner, rather than instantly increasing. This allows the fusion result to sensitively reflect long-term anomalies while avoiding frequent jumps in positioning source weights caused by short-term fluctuations, thereby ensuring the stability of the position output.

[0007] As a further technical solution, the electronic fence, when performing boundary crossing determination, not only makes a single distance judgment but also conducts continuous monitoring. When a person's location approaches the boundary and is in a high-risk condition, the system records the abnormal situation detected each time in multiple subsequent monitoring cycles. If the detected abnormality remains consistent and gradually increases in multiple cycles, it is given higher weight in the cumulative abnormality count. For example, if a rescuer is detected gradually approaching the boundary for four consecutive cycles, and the offset is larger each time than the previous one, the system will double the abnormality count. If the abnormal situation recurs between cycles, such as approaching the boundary and then briefly returning to the safe area, its effect in the abnormality count is weakened. Only when the cumulative abnormality reaches a specified threshold is an alarm event finally triggered. The multi-cycle trend determination and weighted accumulation method enable the electronic fence to reflect boundary crossing risks more reliably while reducing false alarms.

[0008] As a further technical solution, when transmitting alarm events, the forwarding priority of each node in the LoRa self-organizing network is dynamically generated through phased logic. First, nodes are initially sorted according to their remaining battery power, link status, and relative position to the egress node within the current contention cycle. For example, if a node has only 20% battery power remaining, it will be ranked lower in the initial sorting even if its link status is good. Subsequently, during the forwarding process, the historical forwarding success data provided by the main control unit is referenced. If a node has a recent record of continuous packet loss, its priority will be shifted to the next lower order within the current cycle, even if the current signal quality is high. The existing sorting remains unchanged until the end of the contention cycle to avoid frequent adjustments due to short-term fluctuations. The next cycle will then re-evaluate the prioritization. Through this phased evaluation and the combination of historical and current status logic, a stable forwarding sequence is formed, thereby improving the overall reliability of transmission.

[0009] As a further technical solution, when performing differential and segmented coding, the BeiDou short message determines the segment content through a logical priority order. Specifically, when the compressed and encoded data exceeds the allowed transmission length, the first transmission segment must include an alarm identifier, personnel identification information, and core displacement differential data to ensure support for emergency response even under minimum transmission conditions. For example, if the command end can only receive the first segment, the rescue commander can still immediately know which person triggered the alarm at which location. Subsequent segments are sent sequentially according to the order of additional displacement accuracy information and auxiliary parameters. If the receiving end does not receive all subsequent segments within the specified waiting time, it can make a basic response based solely on the first segment information and request retransmission if possible, ensuring that necessary key data can still be obtained under extreme transmission conditions.

[0010] As a further technical solution, the link selection process does not compare latency, coverage, and power consumption metrics simultaneously and with equal weight, but rather uses task-related hierarchical logic. When the rescue team moves at a high speed, the latency metric is temporarily placed with the highest priority for multiple cycles. For example, when a vehicle is traveling at a speed of over 60 kilometers per hour, the system automatically uses latency as the primary judgment condition. When the terminal battery level is below a threshold, the power consumption metric maintains a dominant role in several update cycles. For example, when the battery level is less than 15%, the system will prioritize selecting the link with lower power consumption. When the task is urgent, the coverage metric is immediately elevated to the primary criterion. For example, when the command center issues an immediate evacuation order, the system will prioritize selecting the link with the widest coverage. If multiple switches have occurred recently, the system enters a switch cooling state, and a switch is only executed during the cooling period if an extreme anomaly occurs.

[0011] As a further technical solution, the trajectory database generates a comprehensive judgment through layer-by-layer comparison when retrieving candidate trajectories. First, it compares the differences between the candidate trajectory and the alarm event in the time dimension. If the time difference significantly exceeds a threshold, the trajectory is directly eliminated. For example, if the alarm occurs at night while the candidate trajectory records are mainly from the daytime, the trajectory will be excluded. If the times are similar, the second layer compares the altitude change trend. If the trend difference is significant, the trajectory score is reduced. For example, if the alarm location is on a continuous uphill section while the candidate trajectory records are mainly from flat ground, the trajectory will be downgraded. If the first two layers fail to form a significant difference, the third layer compares the consistency of trajectory types. For example, if one trajectory type is walking while another path is vehicular, the system will make a distinction during the comparison. Only when the three layers of comparison cannot create a significant difference will the system output an uncertainty indicator and feed it back to the main control unit. The main control unit then coordinates the positioning fusion, electronic fence, and link selection modules for joint correction. This layer-by-layer comparison and feedback can provide clear uncertainty prompts in ambiguous situations, thereby improving the reliability of decision-making.

[0012] On the other hand, the present invention provides a fire-fighting outdoor rescue auxiliary system based on multiple communication methods, including: The multi-source positioning module is used to obtain the real-time location information of rescue personnel by combining BeiDou satellite positioning, UWB relative positioning and mobile terminal positioning. The electronic fence module is used to construct a safety boundary based on the location information and monitor whether team members cross the boundary or disconnect. When a cross-boundary or disconnection is detected, an alarm event signal is generated. The communication link detection and switching module is used to receive the alarm event signal, perform real-time detection of the Beidou short message link and the LoRa self-organizing network link, and use the LoRa self-organizing network to complete the alarm event transmission when the LoRa link is detected to be available. When the LoRa link is detected to be unavailable, it switches to the Beidou short message link to transmit the alarm event. During the communication process, it monitors the 4G / 5G link. When the 4G / 5G link is detected to be available, it selects the current optimal link for subsequent alarm event and location information transmission based on the link transmission delay and coverage. The trajectory database management module is used to store historical trajectory data and, upon receiving an alarm event, retrieve relevant trajectory data based on the alarm location and provide the trajectory data and alarm event together to the rescue command terminal. The main control unit coordinates the operation of the multi-source positioning module, the electronic fence module, the communication link detection and switching module, and the trajectory database management module. It enables the coordinated operation of electronic fence triggering, adaptive switching of communication links, and trajectory reference data push, so as to ensure reliable transmission of rescue information and provide path decision support in complex communication environments.

[0013] This invention provides a fire-fighting outdoor rescue assistance method and system based on multiple communication methods, which has the following beneficial effects: 1. This invention solves the problem of frequent changes in the weight of the positioning source under local occlusion or short-term signal fluctuations by using a continuous trend comparison and weight progressive adjustment mechanism in positioning fusion. This improves the stability of the location output in dynamic environments such as valleys and forests, thereby avoiding repeated false alarms triggered by electronic fences and trajectory determination due to instantaneous deviations.

[0014] 2. This invention addresses the inability to distinguish between ordinary and high-risk boundary crossings by overlaying terrain risk indicators and multi-cycle weighted cumulative logic into the electronic fence determination process. This improves the risk identification capability when rescue personnel approach special terrains such as cliffs and steep slopes, thereby significantly enhancing the precision of team safety management without increasing the burden on additional equipment.

[0015] 3. By introducing a switching cooling mechanism and a historical robustness factor during the link switching process, this invention solves the problem of transmission delay fluctuations and instability caused by frequent link switching in rescue communications. It improves the continuity of alarm event and trajectory data transmission under extreme conditions, thereby ensuring that the command end can continuously receive key situation information in uncertain environments and reduce rescue delays caused by unstable communication. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a diagram of the supporting terminal equipment for the present invention; Figure 2 This is a diagram illustrating the trajectory library management of the present invention. Figure 3 This is an offline map layer selection diagram of the present invention; Figure 4 This is a diagram of the electronic fence of the present invention; Figure 5 This invention provides a user-defined route map. Figure 6 This is a user trajectory recording diagram of the present invention; Figure 7 This is the optimal rescue route diagram of the present invention. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, this system uses a dedicated terminal as the hardware platform carried by rescue personnel; the terminal integrates a Beidou positioning chip, a Beidou-3 short message two-way communication unit, a LoRa self-organizing network communication unit, a UWB relative positioning unit, and a mobile terminal positioning interface; the terminal ensures endurance during long-term rescue missions; the satellite signals or relative positioning signals collected by the terminal will be input into the main control unit in a unified format.

[0020] Backend trajectory library management: As attached Figure 2As shown, this system establishes a trajectory library management module on the server side. When a trajectory is added to the library, the system generates a tag for each trajectory. The tag content includes the recording time window, trajectory type identifier, total altitude change, and terrain parameters. The trajectory library supports trajectory review and public access functions. Data that passes review is uploaded to the cloud trajectory database for subsequent retrieval and comparison. When an alarm event is triggered, the system retrieves relevant trajectories from the trajectory library based on the alarm location and time information, and calculates the matching score for time, altitude, and trajectory type. When the score difference is insufficient to determine the optimal trajectory, the system marks it as high uncertainty and feeds this identifier back to the main control unit, which coordinates the positioning fusion module, electronic fence module, and link selection module for joint correction. The system also supports selecting any trajectory from the trajectory library for navigation, including forward and reverse navigation modes. Rescuers can download the trajectory to their local machine when there is a network connection, and combine it with offline map data to achieve smooth path guidance in environments without a public network. During navigation, the system displays real-time location offset reminders, estimated arrival time, and voice prompts for key inflection points to ensure that rescuers can travel along the trajectory efficiently and safely.

[0021] Offline map download management: As attached Figure 3 As shown, this system has an offline map download function; when there is a network connection, rescuers can select the required area and layer type, including ordinary map, satellite map and contour map, and cache the data locally; the map data ensures that smooth zooming and panning can still be achieved in offline mode; after the offline map is combined with real-time positioning data, it can be used for route planning and terrain determination, ensuring that rescuers can still navigate accurately in environments without public network signal.

[0022] Team electronic fence: As attached Figure 4 As shown, this system monitors the activity range of the rescue team through an electronic fence module. The system first constructs a virtual safety boundary based on the multi-source positioning fusion results. When a team member's location approaches the boundary and is in a high-risk area, the electronic fence module doubles the sampling frequency and accumulates anomaly counts over five consecutive monitoring cycles. If the member gradually approaches the boundary in each cycle and the terrain risk level of the area is greater than three, an alarm event is triggered and an emergency call process is initiated. Risk level three indicates a slope exceeding twenty-five degrees or a relative elevation difference greater than fifty meters. If the location briefly returns to a safe area during the monitoring process, the system automatically reduces the anomaly count to avoid false alarms caused by short-term fluctuations.

[0023] Track network management: As attached Figure 5-7As shown, the system's trajectory network function visualizes historical trajectories and forms a network of footprints on the map for reference. Rescuers can refer to previous trajectories to choose routes when carrying out missions. When an alarm event occurs, the trajectory library management module will call the trajectory data related to the alarm location and push it to the rescue command terminal along with the alarm information. The trajectory recording supports four annotation modes: text, audio, photo, and video. Each marker point automatically saves information such as distance from the starting point, altitude, and time. The system supports automatic trajectory recording. After rescuers open the software, the system uses mobile terminal sensors, such as accelerometers and gyroscopes, to assist in positioning. Combined with BeiDou, UWB, and mobile terminal positioning data, the system collects trajectory points in real time and forms trajectory lines, which are automatically saved to local storage. Rescuers can manually publish the trajectory to the cloud trajectory library for subsequent retrieval and sharing. At the same time, the system provides a hand-drawn route planning function, allowing users to simply outline the route by drawing straight lines from point to point. This function is suitable for rescuers familiar with the environment to quickly plan unique routes or design routes for new missions. The planned route can be manually published to the trajectory library, enhancing the flexibility of route planning.

[0024] The communication link detection and switching module plays a crucial role in the entire system. This module includes a link monitoring unit and a switching control unit. The link monitoring unit periodically sends probe messages to the LoRa node group and the BeiDou short message link, and records information such as round-trip delay and received signal strength. The results are stored in the link status table. The switching control unit updates the data based on the results of the last ten samplings. When the link stability is detected to be continuously lower than the threshold, a switching operation is performed. The system only allows a new switching operation when the link is completely interrupted within a one-minute cooling-off period.

[0025] When the LoRa self-organizing network link is available, the system prioritizes forwarding alarm events through the self-organizing network. The forwarding priority of each node is determined by its remaining power, link status, and relative position to the egress node. When a node's power is low, its priority will be reduced even if the link status is good. In addition, the system refers to the recent forwarding success rate and prioritizes historically stable paths. The priority ranking remains unchanged throughout the entire contention cycle until the next cycle when it is updated. When the LoRa link is unavailable, the system automatically switches to the BeiDou short message link. When transmitting data on the BeiDou link, the system uses the anchor point coordinates confirmed by the command end as a reference to calculate the relative displacement of the current position and performs differential and variable-length encoding. When the encoded data exceeds the allowed length, the system divides the data into multiple transmission segments, of which the first transmission segment must contain the alarm identifier and core location information. Even if the receiving end only receives the first segment, it can immediately carry out emergency response. After completing the communication link switch, this system also needs to combine trajectory data and navigation functions to achieve real-time guidance during the rescue process. When rescuers trigger an alarm event, the main control unit will immediately call the trajectory library management module to retrieve relevant trajectories and display them on the offline map. The system calculates similarity based on trajectory type, time window, and terrain parameters, selects the trajectory that best matches the current environment from the candidate set, and overlays it on the offline map to generate a navigation path. During navigation, the system displays the estimated arrival time and remaining distance in real time, and prompts rescuers to approach the bend, intersection, or marker point through voice broadcast. When rescuers deviate from the route, the system will immediately issue a prompt and automatically record new trajectory points to supplement the existing data. The close integration of the navigation function and the trajectory recording module allows rescuers to not only rely on existing trajectories during operations, but also accumulate new path references for subsequent tasks, thereby achieving dynamic data updates and sharing.

[0026] When rescuers face sudden danger, they can trigger the distress call function with a single button on the terminal. After triggering, the system will automatically obtain the current location information and prioritize the available communication method to send information based on the link status. If 4G or 5G network is available, the distress message will be sent immediately through the public network. If the public network is unavailable but the LoRa link is available, the self-organizing network will be used to complete the multi-hop forwarding of the alarm event. If the LoRa link is also unavailable, the system will switch to the Beidou short message link and send the compressed location information and alarm identifier to the command end in segments. The system ensures that at least one link can complete the transmission of critical information in any environment to avoid the loss of distress signals. In mountainous areas without a public network, the average transmission delay of alarm data sent by the system through Beidou short message is 12 seconds, while the average forwarding delay of the LoRa self-organizing network is 6 seconds. Both can meet the timeliness requirements of emergency rescue.

[0027] When the electronic fence module detects that rescuers are approaching the boundary and in a high-risk area, the system not only generates an alarm event but also automatically initiates an emergency distress call process. If necessary, it transmits information to the command center via BeiDou or LoRa links. The trajectory recording and trajectory network functions further provide data support for rescue decision-making. The system records the movement trajectory of rescuers in real time during each rescue mission and allows the addition of markers to the trajectory. Markers can be created using four modes: text, audio recording, photograph, or video recording. The system simultaneously records the distance from the starting point, altitude, and time information of each marker. After the mission is completed, the trajectory data is automatically uploaded to the background trajectory database and publicly displayed in the trajectory network after approval. This allows subsequent rescuers to refer to the trajectory information of predecessors to quickly avoid dangerous areas or find feasible routes. Therefore, the system forms a continuously accumulating and dynamically updated trajectory network, providing long-term assurance for rescue efficiency and success rate.

[0028] Combined with offline map functionality, this system can still provide detailed terrain and road information even in environments without public network signals. Users can download map data for the required area before setting off; the map includes contour lines, satellite imagery, and road information. During rescue operations, the offline map is overlaid with real-time positioning results, enabling rescuers to clearly understand terrain features and formulate reasonable routes. In forest and valley environments, the contour lines displayed on the offline map can reach an accuracy of five meters, clearly reflecting terrain undulations and providing a reliable basis for route planning.

[0029] The entire system's operational logic is uniformly coordinated by the main control unit. The main control unit is responsible for scheduling the operational sequence and data interaction of the multi-source positioning module, electronic fence module, communication link detection and switching module, trajectory database management module, and offline map management module. When a rescue mission is initiated, the main control unit first receives positioning information based on the sampling frequency and performs fusion calculations. Subsequently, the system continuously monitors the team's location and the status of the electronic fence. Once a boundary crossing, disconnection, or abnormal trajectory event occurs, the main control unit immediately triggers communication link detection and selects the optimal link to complete the alarm event transmission. During this process, the trajectory database is synchronously invoked, pushing trajectories related to the alarm location to the command terminal. After receiving the alarm event and trajectory data, the command terminal can view the team's location, trajectory distribution, and map overlay information on the background interface, and quickly formulate a rescue plan.

[0030] The system's effectiveness was verified through multiple field tests. In the multi-source positioning fusion test, the average deviation of BeiDou positioning alone was 8.6 meters, while the average deviation in the fusion mode was reduced to 2.3 meters. In the electronic fence false alarm detection, the false alarm rate of single distance detection was 12%, while the false alarm rate was reduced to 3.5% after introducing terrain risk indicators and multi-cycle weighted logic. In the communication link switching test, without the cooling mechanism, the system switched an average of seven times every ten minutes, with a communication interruption rate of 18%. With the cooling mechanism, the system switched an average of twice every ten minutes, and the communication interruption rate was reduced to 5%. These data objectively reflect the significant improvement of the system in positioning stability, boundary determination accuracy, and communication reliability.

[0031] In summary, this invention, through supporting terminal equipment, a multi-source positioning fusion mechanism, multi-cycle electronic fence judgment logic, adaptive communication link switching strategy, trajectory database and trajectory network management, and offline map support, forms a complete system capable of accurate positioning, safety monitoring, stable communication, and dynamic navigation in complex environments. The modules and functions shown in the accompanying drawings are interconnected during implementation. For example, the supporting terminal equipment provides raw data, the background trajectory database management and trajectory network management provide historical data support, the offline map download management provides basic terrain data, the team's electronic fence and emergency call functions provide safety assurance, and the communication link detection and switching module ensures the reliability of information transmission. The entire system operates collaboratively, effectively improving the efficiency and safety of fire rescue operations.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fire-fighting outdoor rescue assistance method based on multiple communication methods, characterized in that, Includes the following steps: The location information of rescue team members is obtained by combining BeiDou satellite positioning and UWB relative positioning, and then fused with mobile terminal positioning data. Among them, LoRa self-organizing network is used as one of the communication links to transmit the location information and alarm events. Based on the location information, an electronic fence safety boundary is constructed to monitor the activity range of rescue personnel. When a team member is detected to have exceeded the safety boundary or lost connection due to communication interruption, an alarm event is generated and an emergency call process is initiated. When determining the boundary of the electronic fence, the spatial distance judgment must also be combined with the terrain risk index of the corresponding area: when a person's location is less than the boundary and the terrain risk of the grid is higher than the preset level, the sampling frequency of that person is increased and a continuous abnormal count is recorded for several subsequent monitoring cycles; an alarm is triggered and communication link detection is initiated only when the continuous abnormal count reaches a specified number; when the alarm is triggered or deactivated, the electronic fence module writes the abnormal count and risk tag of that person into the shared state for the main control unit and other modules to read and respond in a coordinated manner. In the emergency call process, the communication link detection and switching module is invoked to detect the BeiDou short message link and the LoRa self-organizing network link to ensure that the alarm event is transmitted through one of the BeiDou short message link and the LoRa self-organizing network link when there is no public network signal. When the LoRa self-organizing network link is detected to be available, the alarm event is forwarded using the LoRa self-organizing network. When the LoRa self-organizing network link is detected to be unavailable, the system switches to the BeiDou short message link, compresses and encodes the alarm event and location information, and then transmits it to the rescue command terminal. During the transmission of alarm events, the communication link detection and switching module simultaneously monitors the availability of 4G / 5G links. When the 4G / 5G link is restored, while maintaining the monitoring of Beidou and LoRa self-organizing network links, it selects the link with the best current transmission latency to complete the subsequent information transmission. Simultaneously with the transmission of alarm events, the trajectory database is invoked to retrieve historical trajectory data related to the trigger location. This trajectory data, along with the alarm information, is then pushed to the rescue command center to assist in generating rescue dispatch routes. During the trajectory database retrieval, time, altitude, and type matching scores are calculated for each candidate trajectory to form a comprehensive similarity score. When the score difference between the first and second candidate trajectories is lower than a preset standard, the alarm event is marked as high uncertainty, and an uncertainty flag is sent to the main control unit. Upon receiving the uncertainty flag, the main control unit instructs the multi-source positioning module to use recent communication link stability information as an additional criterion and recalculate the location during subsequent fusion processes. Simultaneously, it instructs the electronic fence module to appropriately adjust the boundary judgment and sampling frequency based on the recalculated location information and the uncertainty flag, and instructs the communication link detection and switching module to prioritize historically robust links in subsequent decisions. This forms a joint feedback mechanism between trajectory retrieval, positioning fusion, electronic fence, and link selection.

2. The fire-fighting outdoor rescue auxiliary method based on multiple communication methods according to claim 1, characterized in that: When jointly acquiring location information, the outputs of BeiDou positioning, UWB relative positioning, and mobile terminal positioning are compared over the most recent sampling periods. When the calculation result of a certain positioning source continuously deviates from the overall position trend over several consecutive periods, the weight of that positioning source in the fusion calculation is gradually reduced. In the fusion calculation, UWB relative positioning data has a higher weight by default. When the BeiDou positioning source shows continuous deviation in a complex environment, it is corrected based on UWB data. After the calculation result of that positioning source recovers consistency with the overall trend over several periods, its weight is gradually restored. By combining satellite visibility indicators with the stability information of received signals, the fused output position can maintain stability in complex obstruction or terrain-variable environments, providing a reliable position input for electronic fence determination.

3. The fire-fighting outdoor rescue auxiliary method based on multiple communication methods according to claim 2, characterized in that: When an alarm event is transmitted through the LoRa self-organizing network, each node determines its forwarding priority based on its remaining power, link status, and relative position to the egress node; and allocates the forwarding order according to priority within the set contention period. If the priority of a node fluctuates within an adjacent contention period, the existing forwarding order will be retained within the current contention period until the end of the contention period before the allocation is updated. At the same time, when the node performs forwarding, it will incorporate recent historical forwarding success information provided by the master control unit to prioritize forwarding paths that are more stable in the past.

4. The fire-fighting outdoor rescue auxiliary method based on multiple communication methods according to claim 3, characterized in that: When an alarm event is sent via the BeiDou short message link, the relative displacement of the current position is calculated based on the anchor point coordinates most recently confirmed by the command terminal, and differential and variable length encoding is performed. When the length of the encoded data exceeds the allowed transmission length, the data is divided into several transmission segments according to priority. The first transmission segment must contain the alarm identifier and key information, and subsequent segments are sent in sequence and reassembled at the receiving end according to the segment order. If the subsequent segment is not received within the specified waiting time, the receiving end will take emergency measures based on the information in the first segment and request retransmission or use a backup link to make up for the missing data.

5. A fire-fighting outdoor rescue auxiliary method based on multiple communication methods according to claim 4, characterized in that: Link selection is based on three metrics: latency, coverage, and power consumption, and the evaluation results are updated regularly. When the rescue team moves at a high speed, the latency metric will be given higher priority within a few update cycles. When the terminal battery is low, the power consumption metric will be given priority within a few update cycles. When the task is urgent, the coverage metric will be given higher priority immediately. In addition, if multiple link switchings have occurred recently, new switching requests will be suspended until the switching frequency falls back to the allowable range to avoid communication instability caused by frequent switching.

6. A fire-fighting outdoor rescue auxiliary system based on multiple communication methods, used to implement the fire-fighting outdoor rescue auxiliary method based on multiple communication methods as described in any one of 1-5, characterized in that, include: The multi-source positioning module is used to obtain the real-time location information of rescue personnel by combining BeiDou satellite positioning, UWB relative positioning and mobile terminal positioning. The electronic fence module is used to construct a safety boundary based on the location information and monitor whether team members cross the boundary or disconnect. When a cross-boundary or disconnection is detected, an alarm event signal is generated. The communication link detection and switching module is used to receive the alarm event signal, perform real-time detection of the Beidou short message link and the LoRa self-organizing network link, and use the LoRa self-organizing network to complete the alarm event transmission when the LoRa link is detected to be available. When the LoRa link is detected to be unavailable, it switches to the Beidou short message link to transmit the alarm event. During the communication process, it monitors the 4G / 5G link. When the 4G / 5G link is detected to be available, it selects the current optimal link for subsequent alarm event and location information transmission based on the link transmission delay and coverage. The trajectory database management module is used to store historical trajectory data and, upon receiving an alarm event, retrieve relevant trajectory data based on the alarm location and provide the trajectory data and alarm event together to the rescue command terminal. The main control unit coordinates the operation of the multi-source positioning module, the electronic fence module, the communication link detection and switching module, and the trajectory database management module. It enables the coordinated operation of electronic fence triggering, adaptive switching of communication links, and trajectory reference data push, so as to ensure reliable transmission of rescue information and provide path decision support in complex communication environments.

7. A fire-fighting outdoor rescue auxiliary system based on multiple communication methods according to claim 6, characterized in that, The communication link detection and switching module includes a link monitoring unit and a switching control unit. The link monitoring unit is used to periodically send probe messages to the LoRa node group and the BeiDou short message link to obtain the round-trip delay and the received signal strength, and store the sampling results in the link status table. The switching control unit updates the link status table based on the historical sampling results and real-time status, and performs a switching operation when the stability index of a certain path is continuously lower than a preset threshold. At the same time, it generates and stores a switching log locally.

8. A fire-fighting outdoor rescue auxiliary system based on multiple communication methods according to claim 7, characterized in that, The trajectory library management module includes a trajectory tag processing unit. When storing a trajectory, the trajectory tag processing unit generates tags for it, including the recording time window, trajectory type identifier, total altitude change and terrain parameters. During the trajectory retrieval process, the time window of the alarm event and the terrain parameters are used as the primary matching conditions to filter the trajectory candidate set. The unit prioritizes outputting trajectory data that is consistent with the current alarm environment tags to improve the adaptability of trajectory reference to rescue scenarios.

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