A system and method for deploying a communication repeater within a tunnel

Abstract

The application provides a tunnel communication repeater arrangement system and method, and relates to the technical field of repeater arrangement.The tunnel communication repeater arrangement system comprises a vehicle, a vehicle-mounted communication terminal, a repeater and a repeater deployment device, the repeater is internally integrated with a control unit, and the vehicle-mounted communication terminal is in communication connection with the control unit and the deployment device.The method comprises the following steps: the vehicle-mounted communication terminal monitors the communication signal strength and rate in real time, and sends a working instruction to the control unit and the deployment device when the signal is lower than a threshold value; the control unit controls the repeater to start and acquire a signal of a previous device, analyzes and obtains a specified deployment position; the deployment device carries the repeater to the position for deployment; the deployed repeater automatically establishes a backhaul link and opens network coverage; and the vehicle-mounted communication terminal is automatically switched to the repeater with the strongest signal.The application can automatically and accurately arrange the repeater, avoids too many or too few repeaters, ensures smooth communication and saves costs.

Description

Technical Field

[0001] This invention relates to the field of repeater deployment technology, and more specifically, to a system and method for deploying communication repeaters in tunnels. Background Technology

[0002] In various tunnel scenarios (such as traffic tunnels, municipal utility tunnels, and coal mine roadways), tunnel structures are typically long, winding, and have numerous branches, and are shielded by surrounding rock or lining, preventing direct coverage of the interior by external wireless signals. Especially in high-dust environments, manually deploying communication equipment on-site poses significant safety risks and operational difficulties; therefore, equipment deployment must rely on non-manual methods. With the advancement of intelligent tunnel operation and maintenance, the need for real-time communication between vehicles operating inside (such as transport vehicles, inspection robots, and tunneling / operation machinery) and the ground dispatch center, as well as between vehicles themselves, is becoming increasingly urgent. This is particularly true in remote-controlled dust removal operations and dust monitoring data transmission, where the continuity and reliability of communication directly impact operational safety and efficiency.

[0003] Existing tunnel communication technologies have the following main shortcomings: 1. The current deployment location of repeaters cannot be precisely set according to the signal coverage range of the repeaters. If the distance between the repeater and the previous repeater or base station is too far, the signal transmission between the repeaters will be affected, and the communication between the repeater and the previous repeater or base station will be affected. If the distance between the repeater and the previous repeater or base station is too close, although the communication needs can be met, too many repeaters will be deployed, resulting in increased costs.

[0004] 2. Manual Repeater Deployment: Repeaters are manually deployed by personnel carrying them into the tunnel. In various high-dust environments within tunnels, manual deployment of communication equipment presents safety risks and operational difficulties. Furthermore, manual deployment is slow, has a delayed response time, and cannot dynamically adjust the repeater's position while the vehicle is moving, making it difficult to meet the continuous communication needs of moving vehicles as the tunnel is being developed. Especially with the increasing intelligence of tunnels, the need for real-time communication between vehicles operating inside (such as transport vehicles, inspection robots, tunneling / operation machinery, etc.) and the ground dispatch center, as well as between vehicles themselves, is becoming increasingly urgent. Particularly in situations such as remote-controlled dust removal operations and dust monitoring data transmission, the continuity and reliability of communication directly affect operational safety and efficiency.

[0005] 3. Some existing systems allow vehicles to carry and deploy a repeater, which is then deployed to extend communication distance when the vehicle enters a signal dead zone. However, as the vehicle continues to move deeper into the tunnel, it gradually moves away from the deployed repeater, causing the signal to weaken again, making long-distance continuous communication impossible. Long-distance tunnel scenarios often extend for several kilometers or even tens of kilometers, and a single repeater cannot meet the communication needs throughout the entire journey.

[0006] Therefore, there is an urgent need in the field for a system and method specifically designed for high-dust tunnel environments, capable of automatically and continuously deploying multiple repeaters as vehicles move, and ensuring uninterrupted communication signals between each repeater. Summary of the Invention

[0007] The purpose of this invention is to provide a system and method for deploying communication repeaters in tunnels, which can automatically and continuously deploy multiple repeaters and ensure that each repeater is accurately deployed. This avoids deploying too many or too few repeaters, ensures smooth communication between repeaters, and saves deployment costs.

[0008] The embodiments of the present invention are implemented as follows: In a first aspect, embodiments of this application provide a system for deploying communication repeaters in tunnels, comprising: vehicle; Vehicle-mounted communication terminal, installed on a vehicle, is used for wireless communication between the vehicle and a base station or repeater; At least one repeater, each of which integrates a control unit for controlling the establishment of communication links and network coverage; A repeater deployment device, which is used to load repeaters and carry repeaters for automatic movement and deployment; The vehicle-mounted communication terminal is connected to both the control unit and the repeater deployment device.

[0009] In some embodiments of the present invention, the repeater includes: Battery module, used for power supply; The wireless backhaul module is used to establish a backhaul link with the upstream base station or upstream repeater. Wireless coverage module, used to provide network coverage; The control module integrates the control unit and is used to control the working status of the wireless backhaul module and the wireless coverage module.

[0010] In some embodiments of the present invention, the repeater deployment device is at least one of a drone, a mechanical dog, or a robot.

[0011] In some embodiments of the present invention, the above-mentioned vehicle-mounted communication terminal includes: The signal strength detection module is used to monitor the signal strength of the current communication connection in real time. The rate detection module is used to monitor the communication rate of the current communication connection in real time. The threshold comparison module is used to compare the detected signal strength with the first set threshold S1 and the third set threshold S2, and to compare the detected communication rate with the second set threshold B1. The instruction sending module is used to send a working instruction to the repeater deployment device when the signal strength is lower than S1 or the communication rate is lower than B1. The switching decision module is used to select the repeater with the strongest signal and switch communication when the signal strength of the detected repeater is higher than the third set threshold S2.

[0012] Secondly, embodiments of this application provide a method for deploying a communication repeater in a tunnel, comprising the following steps: Step A: The vehicle-mounted communication terminal establishes communication with the base station or repeater of the current communication connection, and monitors the signal strength and communication connection speed of the communication connection in real time while the vehicle is moving in the tunnel; Step B: When the signal strength is lower than the first set threshold S1, or the communication connection rate is lower than the second set threshold B1, the vehicle communication terminal sends a working instruction to the repeater deployment device and the control unit; Step C: After receiving the working instruction, the control unit controls the repeater to start. The repeater acquires the signal from the deployed repeater or base station and monitors the strength and communication connection rate of the acquired signal in real time. The control unit analyzes and processes the signal strength and communication connection rate to obtain the designated deployment location of the repeater. After receiving the work instruction, the repeater deployment device carries the repeater and moves to the designated deployment location, where it deploys the repeater. Step D: The deployed repeater enters the working state, automatically scans and selects the upstream base station or upstream repeater whose signal quality meets the preset standard to establish a backhaul link, and ensures that the communication rate and communication delay of the backhaul link meet the communication requirements of the vehicle communication terminal. Step E: After the repeater successfully establishes the backhaul link, the repeater activates its own network coverage function. Step F: After the repeater activates its own network coverage function, when the vehicle communication terminal detects that there is a signal with a signal strength higher than the third set threshold S2 among the repeaters that can be associated, it automatically selects the repeater with the strongest signal to associate with and switches to communicate with that repeater. Step G: As the vehicle continues to move forward, when the signal strength is lower than S1 again or the communication connection rate is lower than B1 again, repeat steps B to F above, thereby continuously and automatically deploying multiple repeaters during the vehicle's movement to form a dynamically extended communication link.

[0013] In some embodiments of the present invention, in step C above, the repeater deployment device returns to the vehicle by automatically returning along the original path, or by returning to the vehicle's current position according to a preset path plan.

[0014] In some embodiments of the present invention, in step D above, the repeater enters the working state in the following manner: the repeater is already in the start-up state before being deployed to the designated location, and automatically starts scanning and matching the upstream device with the strongest signal after deployment is completed.

[0015] In some embodiments of the present invention, in step E above, the wireless frequency band used by the network coverage function activated by the repeater is different from the wireless coverage frequency band of the upstream base station or the upstream repeater.

[0016] In some embodiments of the present invention, the aforementioned upstream base station or upstream repeater uses a first frequency band N1 for coverage, and the repeater uses a second frequency band N2 that does not interfere with the first frequency band N1 for coverage.

[0017] In some embodiments of the present invention, the designated deployment location in step C above is determined based on the current vehicle location, the location of the previous level base station or the previous level repeater, and the signal attenuation model, so as to ensure that the backhaul link communication quality between the repeater and the previous level base station or the previous level repeater meets the preset requirements.

[0018] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: This invention provides a deployment system for communication repeaters in tunnels. Each repeater integrates a control unit. When the signal strength falls below a threshold, an onboard communication terminal sends a working command to the control unit and the repeater deployment equipment. The control unit analyzes and calculates the designated deployment location of the repeater based on the monitored signal strength and rate. The repeater deployment equipment loads the repeater and moves it to the designated deployment location for deployment. Compared to existing deployment methods that rely on manual experience or fixed spacing, this system ensures that the distance between newly deployed repeaters and upstream equipment remains at an optimal balance point within the effective signal coverage range. This avoids signal attenuation, rate reduction, and increased latency in the backhaul link due to excessive distance, while also preventing overly dense repeater deployment, increased quantity, and higher costs due to excessively close distance. Thus, it achieves precise deployment location and dual optimization of communication quality and deployment cost.

[0019] In addition, the repeater deployment equipment automatically completes the loading, movement and release of the repeater. The entire process does not require manual entry into the high-risk environment of the tunnel, eliminating the threat to personnel from dust, high temperature and humidity, etc., while greatly improving deployment speed and real-time response.

[0020] This invention also provides a method for deploying communication repeaters in tunnels. In step B, the vehicle-mounted communication terminal monitors signal strength and communication rate in real time. When the signal strength is lower than a first preset threshold S1 or the communication rate is lower than a second preset threshold B1, it sends a working instruction to the control unit and the repeater deployment equipment. The repeater monitors the signals of deployed repeaters or base stations through the control unit and analyzes and processes the data to obtain a precise designated deployment location. Determining the deployment location based on the signal quality monitored in real time by the repeater ensures that the deployment decision is always based on the actual communication quality. This achieves quantitative calculation and precise control of the deployment location, avoiding both a decrease in backhaul link rate and an increase in latency due to excessive distance, and an overly dense deployment of repeaters due to excessive proximity, resulting in wasted costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 This is a flowchart of Embodiment 2 of the present invention.

[0023] Icons: 1-Vehicle; 2-Vehicle communication terminal; 3-Repeater; 4-Repeater deployment equipment. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] Example 1 Please refer to Figure 1This embodiment provides a tunnel-based communication repeater deployment system, including a vehicle, a vehicle-mounted communication terminal, at least one repeater, and a repeater deployment device. The vehicle-mounted communication terminal is installed on the vehicle and is used for wireless communication with a base station or repeater. Each repeater integrates a control unit for controlling the establishment of the repeater's communication link and network coverage. The repeater deployment device carries the repeaters and performs automatic movement and deployment. The vehicle-mounted communication terminal is communicatively connected to both the control unit and the repeater deployment device.

[0027] In this embodiment, the vehicle carries a repeater and repeater deployment equipment, and is also equipped with an on-board communication terminal. When the vehicle moves into the tunnel, the on-board communication terminal first establishes communication with the base station outside the tunnel or the upstream repeater, and monitors the signal strength and communication connection speed of the communication connection in real time during the vehicle's movement inside the tunnel.

[0028] As the vehicle moves deeper into the terrain, the onboard communication terminal determines whether the signal strength is below a first preset threshold S1 or whether the communication connection rate is below a second preset threshold B1. If one or more of these conditions are met, the onboard communication terminal sends a working command to the repeater deployment device and the control unit. Upon receiving the working command, the control unit activates the repeater. The repeater acquires signals from deployed repeaters or base stations and monitors the signal strength and communication connection rate in real time. Based on this information, the control unit analyzes and processes the data to determine the designated deployment location of the repeater.

[0029] After receiving the work instruction, the repeater deployment equipment carries the repeater to the designated deployment location and deploys it there. Subsequently, the deployed repeater automatically scans and selects a previous-level base station or repeater whose signal quality meets preset standards to establish a backhaul link, ensuring that the communication rate and latency of this backhaul link meet the communication requirements of the vehicle-mounted communication terminal. After successfully establishing the backhaul link, the repeater activates its own network coverage function. Once this function is activated, if the vehicle-mounted communication terminal detects a repeater with a signal strength higher than the third preset threshold S2 among the available repeaters, it automatically selects the repeater with the strongest signal for association and switches to communicating with that repeater.

[0030] In this embodiment, the repeater deployment device loads and carries the repeaters for automatic movement and deployment. Combined with real-time signal monitoring and command triggering by the control unit, the deployment location of the repeaters can be accurately determined based on the current vehicle location, the location of the upstream base station or repeater, and the signal attenuation model. Compared to existing technologies that rely on manual experience or fixed spacing, this system ensures that the distance between newly deployed repeaters and upstream equipment is always at the optimal balance point within the effective signal coverage range. This avoids both excessive distance leading to signal attenuation, reduced speed, and increased latency in the backhaul link, and excessively close distance resulting in overly dense repeater deployment, increased quantity, and higher costs. Thus, it achieves precise deployment location and dual optimization of communication quality and deployment cost.

[0031] In addition, the repeater deployment equipment automatically completes the loading, movement and release of the repeater. The entire process does not require human personnel to enter the high-dust and high-risk environment of the tunnel, eliminating the threat to personnel from dust, high temperature and high humidity, while greatly improving deployment speed and real-time response.

[0032] Preferably, in this embodiment, the repeater includes a battery module, a wireless backhaul module, a wireless coverage module, a control module, and a positioning module. The battery module provides power, offering an independent power source for the entire repeater. Specifically, in this embodiment, an explosion-proof lithium battery with a capacity sufficient for continuous operation of the repeater for over 48 hours is used. The battery module allows the repeater to operate without an external power source, enabling its deployment on side walls, tops, or the ground, unrestricted by underground power lines. Compared to wired repeaters, this significantly reduces deployment difficulty and cost.

[0033] The aforementioned wireless backhaul module is used to establish a backhaul link with the upstream base station or upstream repeater. This module operates in a dedicated backhaul frequency band (e.g., 1.8GHz LTE, 5.8GHz, etc.), offering long transmission distances and strong penetration capabilities. After the repeater is deployed, the control module drives the wireless backhaul module to scan surrounding signals, select the parent node with the best signal quality, initiate a connection request, complete authentication, and maintain the link. Furthermore, this wireless backhaul module is also responsible for forwarding uplink data received from the coverage module to the upstream device and forwarding downlink data received from the upstream device to the coverage module.

[0034] The aforementioned wireless coverage module provides network coverage. This module operates in a coverage frequency band (such as 2.4GHz WiFi), different from the backhaul band, to avoid co-channel interference. Once activated, it periodically broadcasts beacon frames for vehicle-mounted communication terminals to scan and associate with. The vehicle-mounted communication terminals connect to the repeater through this module to achieve data communication.

[0035] The aforementioned control module integrates the control unit, which is responsible for coordinating the working status of each module and controlling the working status of the wireless backhaul module and the wireless coverage module. After the repeater receives the working command and starts, the control module controls the repeater to acquire the signal of the deployed repeater or base station according to the preset logic and monitors it in real time, analyzes and processes it to obtain the specified deployment location; after deployment is completed, the backhaul link establishment process is started; after successful establishment, the coverage module is then activated; during operation, the link quality is continuously monitored, and reconnection or switching of parent nodes is triggered when necessary.

[0036] The aforementioned positioning module is used to acquire the location information of the repeaters. Specifically, in this embodiment, the positioning module employs UWB ultra-wideband positioning, inertial navigation, or interaction with pre-installed positioning tags within the tunnel. During repeater deployment, the positioning module reports its own coordinates to the system via a backhaul link, facilitating the network management platform's understanding of the distribution topology of each repeater. When the system triggers a new deployment, the location information of the previous-level repeater provided by the positioning module is used to calculate the target deployment location of the new repeater.

[0037] Preferably, in this embodiment, the repeater deployment device is at least one of a drone, a robotic dog, or a robot. Specifically, the user can select one or more of a drone, a robotic dog, or a robot as the repeater deployment device according to the specific conditions of the tunnel.

[0038] Among them, drones are suitable for scenarios with large tunnel cross-sections, no severe airflow disturbances, and high deployment positions. Drones fly at high speeds and can quickly cross ground obstacles, making them particularly suitable for situations requiring long-distance, rapid deployment. Robotic dogs are suitable for scenarios with uneven ground but where flight is not required. Robotic dogs are quadrupedal, have strong traversal capabilities, and can move stably on tunnel surfaces with tracks, cable trenches, and slight water accumulation. They have a large load capacity and long endurance. Robots generally refer to tracked or wheeled mobile platforms, suitable for scenarios with good ground conditions, short deployment distances, and precise parking requirements. Robots are lower in cost, easier to maintain, and can be equipped with more complex robotic arms for delicate operations.

[0039] Furthermore, the aforementioned mechanical interface enables the automatic grabbing, carrying, and release of the repeater, all without human intervention, eliminating the safety risks of personnel entering dangerous roadways. After completing one deployment and returning to the vehicle, the mechanical interface can be used to load new repeaters, allowing the repeater deployment equipment to be reused multiple times.

[0040] Preferably, in this embodiment, the vehicle-mounted communication terminal includes a signal strength detection module, a rate detection module, a threshold comparison module, a command sending module, and a handover decision module.

[0041] The signal strength detection module is used to monitor the signal strength of the current communication connection in real time. This module periodically (e.g., every 200ms) reads the Reference Received Power (RSRP) reported by the physical layer. To suppress fast fading and noise interference, the module internally employs a sliding window averaging filter algorithm (window length N=5) to output a smoothed signal strength value. .

[0042] The aforementioned rate detection module is used to monitor the communication rate of the current communication connection in real time; it calculates the real-time throughput by counting the number of data packets successfully transmitted per unit time. It also uses a sliding window averaging method (window length N=5) to output a smoothed rate value. .

[0043] The threshold comparison module described above compares the monitored signal strength with a first preset threshold S1 and the monitored communication rate with a second preset threshold B1. The preset thresholds S1 and B1 can be dynamically adjusted according to communication service requirements (voice, video, data, etc.). The comparison is performed in each measurement cycle: if… or If the condition is met, a "trigger condition satisfied" signal is output. To prevent false triggering due to momentary fluctuations, the threshold comparison module also includes continuous counting logic: the trigger flag is only output after the condition is met M times consecutively. The trigger flag of the threshold comparison module is a Boolean value, which can be used by the instruction sending module described below. The sliding window filtering and the M-times consecutive counting logic effectively suppress false triggering caused by momentary fading (such as brief signal fluctuations caused by a vehicle passing through a vent). Experimental data shows that the false triggering rate is reduced by more than 90% after adopting this mechanism, avoiding unnecessary parking and repeater waste.

[0044] The aforementioned command sending module is used to send working commands to the repeater deployment device and control unit when the signal strength is lower than S1 or the communication rate is lower than B1. The command sending module sends working commands to the repeater deployment device via wireless communication, and the command data packet includes at least the specified deployment location and repeater number. Furthermore, the command sending module also has a timeout retransmission mechanism: if the deployment device does not reply with confirmation within a specified time, the command is retransmitted, up to a maximum of three times.

[0045] The aforementioned switching decision module is used to select the repeater with the strongest signal for association and to switch communication when the signal strength of the detected repeater is higher than S2. The aforementioned scanning period is... Actively detect the beacon frames broadcast by each repeater and measure their... Constructing a candidate set If C is empty, maintain the current link. (The above...) Select the optimal repeater by assigning it an index number (e.g., the first repeater, the second repeater, etc.). .like Unlike current service repeaters, The signal strength value of the selected optimal repeater. For switching hysteresis, and (Hysteresis 3dB), then perform a switch: to (The index of the selected optimal repeater) sends an association request to establish a new link. Data forwarding is maintained on both the old and new links for 3 seconds. Once the new link stabilizes, the old link is disconnected, and the current serving repeater is updated. Thus, the handover decision module achieves optimal relay selection based on signal strength and supports soft handover. Communication is not interrupted when the vehicle moves from the coverage area of ​​the old repeater to the coverage area of ​​the new repeater.

[0046] Example 2 Please refer to Figure 2 This embodiment provides a method for automatically deploying repeaters in a tunnel, including the following steps: Step A: The vehicle-mounted communication terminal establishes communication with the currently connected base station or repeater, and monitors the signal strength and communication speed of this connection in real time as the vehicle moves within the tunnel. Specifically, the vehicle-mounted communication terminal interacts with the currently connected base station or repeater at fixed intervals to extract the received signal strength (SMS). ) and communication rate To suppress downhole multipath fading and transient interference, a sliding window averaging filter is used to output a smoothed result. and Simultaneously, a continuous counter is started to record the number of times the value is continuously below the threshold. This step A provides accurate and stable communication quality metrics, laying the data foundation for trigger judgment and avoiding false triggers caused by instantaneous fluctuations.

[0047] Step B: When the signal strength is lower than the first preset threshold S1, or the communication connection rate is lower than the second preset threshold B1, the vehicle-mounted communication terminal sends working instructions to the repeater deployment device and control unit. When this occurs... or If a record is made once, and this occurs M times consecutively, the communication quality is considered to have degraded to a critical value. At this point, the vehicle-mounted communication terminal sends operating instructions to the repeater deployment equipment and control unit.

[0048] Step C: After receiving the work instruction, the control unit activates the repeater. The repeater acquires signals from deployed repeaters or base stations and monitors the signal strength and communication connection rate in real time. The control unit analyzes and processes the signal strength and communication connection rate to determine the designated deployment location for the repeater. After receiving the work instruction, the repeater deployment device carries the repeater and moves to the designated deployment location, where it deploys the repeater.

[0049] Specifically, after receiving the work instruction, the repeater deployment equipment loads a repeater and automatically moves along the roadway to the target deployment location. . The control unit calculates the path loss based on the signal attenuation model, using a logarithmic distance path loss model.

[0050] Ensure the distance between the new repeater and the upstream equipment. ,satisfy Once the repeater deployment equipment reaches the deployment location, the repeater is released. In this way, the repeater can be precisely deployed in a location that can both receive the upstream signal well and provide high-quality coverage for the vehicle, avoiding poor link due to being too far away and waste due to being too close.

[0051] Step D: The deployed repeater enters the working state, automatically scanning and selecting a previous-level base station or repeater whose signal quality meets preset standards to establish a backhaul link, ensuring that the communication rate and latency of this backhaul link meet the communication requirements of the vehicle-mounted communication terminal. Specifically, the repeater enters the working state after deployment (or through pre-startup). Its control unit drives the wireless backhaul module to scan the beacons of surrounding base stations and deployed repeaters, measuring the beacons of each candidate device. , (Refer to signal reception quality (signal-to-interference ratio)) and hop count. Based on the overall score, select the optimal parent node (e.g., prioritize nodes with strong signal and low hop count), initiate a connection request, and complete authentication. After establishment, test round-trip latency and packet loss rate; if these are not met, try the next best node. In this way, repeater self-organized access can be achieved without manual configuration, while also ensuring the quality of the backhaul link.

[0052] Step E: After the repeater successfully establishes the backhaul link, it activates its own network coverage function. This local coverage enables the vehicle-mounted communication terminal to connect to the new repeater. The purpose of this step is to provide local coverage, allowing the vehicle-mounted communication terminal to connect to the new repeater. Frequency band misalignment avoids co-channel interference and ensures the stable operation of the multi-level repeater system.

[0053] Step F: After the repeater activates its network coverage function, when the vehicle communication terminal detects a repeater with a signal strength higher than the third preset threshold S2, it automatically selects the repeater with the strongest signal for association and switches to communicating with that repeater. This ensures that the vehicle is always associated with the optimal repeater, and communication is uninterrupted.

[0054] Step G: As the vehicle continues to move forward, when the signal strength drops below S1 again or the communication connection rate drops below B1 again, steps B to F are repeated. This continuously and automatically deploys multiple repeaters during the vehicle's movement, forming a dynamically extended communication link. Step G achieves the infinite extension of the communication link. As long as the vehicle continues to move and there are enough repeaters, new repeaters can be continuously deployed, thus covering tunnel scenarios of any length. This is a key mechanism for solving long-distance continuous communication.

[0055] In summary, during the above steps, the vehicle-mounted communication terminal monitors signal strength and communication rate in real time. When the signal strength falls below the first preset threshold S1 or the communication rate falls below the second preset threshold B1, it sends a working command to the control unit and the repeater deployment equipment. The repeater monitors the signals of deployed repeaters or base stations through the control unit, analyzes and processes the data to obtain the designated deployment location. Determining the deployment location based on the signal quality monitored in real time by the repeater ensures that deployment decisions are always based on actual communication quality. This achieves quantitative calculation and precise control of the deployment location, avoiding both a decrease in backhaul link speed and an increase in latency due to excessive distance, and an over-density deployment of repeaters due to excessive proximity, resulting in wasted costs.

[0056] Preferably, in step C above, the repeater deployment device returns to the vehicle either automatically along the original path or according to a preset path plan to return to the vehicle's current location. Automatically returning along the original path utilizes the verified collision-free route from the outward journey, avoiding the uncertainties that might be introduced by replanning. In tunnel scenarios, this means that even without a global map or positioning signal, the device can reliably return, ensuring the reusability of the deployed device.

[0057] Preferably, in this embodiment, in step D above, the repeater enters the working state in the following way: the repeater is already in the activated state before being deployed to the designated location, and automatically begins scanning and matching the upstream device with the strongest signal after deployment is completed. Since the repeater is activated before deployment, there is no need for the deploying device to send an additional activation command after release, which further simplifies the deployment process and reduces deployment time.

[0058] Preferably, in this embodiment, in step E above, the wireless frequency band used by the repeater to activate its network coverage function is different from the wireless coverage frequency band of the upstream base station or the upstream repeater. Each repeater prepares to activate its own network coverage function after completing the backhaul link establishment. Before activation, the repeater's control unit first obtains the wireless coverage frequency band information used by the current parent node (upstream base station or repeater). This information can be obtained through the following methods: the parent node informs the child node of its coverage frequency band parameters through a handshake message during the backhaul link establishment process. The repeater directly obtains its operating frequency band by scanning surrounding wireless signals and parsing the parent node's beacon frames. After obtaining the parent node's frequency band, the repeater selects a frequency band different from the supported frequency band list as its own coverage frequency band. Optional frequency band resources typically include: 2.4GHz, 1.8GHz, 5.8GHz, 700MHz, etc.

[0059] In tunnel scenarios, which are enclosed spaces with severe signal reflection, if multiple relays use the same frequency band for coverage, the vehicle-mounted communication terminal will simultaneously receive multiple strong signals, resulting in co-channel interference (intermodulation distortion, receiver blocking, etc.) and a sharp increase in the bit error rate. This embodiment forces adjacent relays to use different frequency bands, ensuring that the vehicle-mounted communication terminal can only clearly receive the coverage signal of one relay at a time, thus achieving better anti-interference performance.

[0060] Furthermore, by employing the above technical solution, when the vehicle moves between the front and rear repeaters, if the two repeaters operate on different frequencies, the onboard communication terminal can independently measure the signal strength of each frequency band, avoiding measurement errors caused by co-channel interference (when operating on the same frequency, the two signals are superimposed, resulting in incorrect measurements). (It may be artificially inflated). In this way, the handover decision module can accurately judge the signal strength, thereby achieving a smooth, ping-pong-free handover, which can greatly improve the success rate of the above handover in the case of inter-frequency deployment.

[0061] Furthermore, in this embodiment, the aforementioned upstream base station or upstream repeater uses the first frequency band N1 for coverage, and the repeater uses the second frequency band N2, which does not interfere with the first frequency band N1, for coverage. Operators can directly refer to N1 and N2 for frequency planning, for example, specifying that all base stations use N1=1.8GHz, all odd-numbered repeaters use N2=2.4GHz, even-numbered repeaters use N3=5.8GHz, and so on. This explicitness reduces the possibility of configuration errors, ensuring that the wireless frequency band used by the network coverage function enabled by the aforementioned repeater differs from the wireless coverage frequency band of the upstream base station or upstream repeater.

[0062] Preferably, in this embodiment, the specified deployment location in step C is determined based on the current vehicle location, the location of the upstream base station or upstream repeater, and the signal attenuation model, to ensure that the backhaul link communication quality between the repeater and the upstream base station or upstream repeater meets preset requirements. Specifically, the signal attenuation model is described below: This embodiment uses a logarithmic distance path loss model, which has been verified by field tests in a tunnel environment and has high accuracy.

[0063] in: Current vehicle location The relationship between the target deployment location and the distance to the target is determined by the lead distance. After the vehicle stops in step B, Acquired by vehicle positioning system (such as inertial navigation + UWB tag or pre-set reference points in the alley); Location of the upstream device: If the upstream is a fixed base station, its coordinates are pre-stored in the system; if the upstream is a deployed repeater, the coordinates are obtained through the positioning module of that repeater. This refers to the distance (m) between the new repeater and the upstream device. For reference distance (1 meter in this example) This represents the signal strength measured at the reference distance.

[0064] It is the path loss index, which depends on the roadway cross-section, support material, and degree of curvature.

[0065] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A system for deploying communication repeaters in tunnels, characterized in that, include: vehicle; Vehicle-mounted communication terminal, installed on a vehicle, is used for wireless communication between the vehicle and a base station or repeater; At least one repeater, each of which integrates a control unit for controlling the establishment of communication links and network coverage; A repeater deployment device, which is used to load repeaters and carry repeaters for automatic movement and deployment; The vehicle-mounted communication terminal is connected to both the control unit and the repeater deployment device.

2. The system according to claim 1, characterized in that, The repeater includes: Battery module, used for power supply; The wireless backhaul module is used to establish a backhaul link with the upstream base station or upstream repeater. Wireless coverage module, used to provide network coverage; The control module integrates the control unit and is used to control the working status of the wireless backhaul module and the wireless coverage module.

3. The system according to claim 1, characterized in that, The repeater deployment device is at least one of a drone, a robotic dog, or a robot.

4. The system according to claim 1, characterized in that, The vehicle-mounted communication terminal includes: The signal strength detection module is used to monitor the signal strength of the current communication connection in real time. The rate detection module is used to monitor the communication rate of the current communication connection in real time. The threshold comparison module is used to compare the detected signal strength with the first set threshold S1 and the third set threshold S2, and to compare the detected communication rate with the second set threshold B1. The instruction sending module is used to send a working instruction to the repeater deployment device when the signal strength is lower than S1 or the communication rate is lower than B1. The switching decision module is used to select the repeater with the strongest signal and switch communication when the signal strength of the detected repeater is higher than the third set threshold S2.

5. A method for deploying communication repeaters in tunnels, characterized in that, Includes the following steps: Step A: The vehicle-mounted communication terminal establishes communication with the base station or repeater of the current communication connection, and monitors the signal strength and communication connection speed of the communication connection in real time while the vehicle is moving in the tunnel; Step B: When the signal strength is lower than the first set threshold S1, or the communication connection rate is lower than the second set threshold B1, the vehicle communication terminal sends a working instruction to the repeater deployment device and the control unit; Step C: After receiving the working instruction, the control unit controls the repeater to start. The repeater acquires the signal from the deployed repeater or base station and monitors the strength and communication connection rate of the acquired signal in real time. The control unit analyzes and processes the signal strength and communication connection rate to obtain the designated deployment location of the repeater. After receiving the work instruction, the repeater deployment device carries the repeater and moves to the designated deployment location, where it deploys the repeater. Step D: The deployed repeater enters the working state, automatically scans and selects the upstream base station or upstream repeater whose signal quality meets the preset standard to establish a backhaul link, and ensures that the communication rate and communication delay of the backhaul link meet the communication requirements of the vehicle communication terminal. Step E: After the repeater successfully establishes the backhaul link, the repeater activates its own network coverage function. Step F: After the repeater activates its own network coverage function, when the vehicle communication terminal detects that there is a signal with a signal strength higher than the third set threshold S2 among the repeaters that can be associated, it automatically selects the repeater with the strongest signal to associate with and switches to communicate with that repeater. Step G: As the vehicle continues to move forward, when the signal strength is lower than S1 again or the communication connection rate is lower than B1 again, repeat steps B to F above, thereby continuously and automatically deploying multiple repeaters during the vehicle's movement to form a dynamically extended communication link.

6. The method according to claim 5, characterized in that, In step C, the repeater deployment device returns to the vehicle by either automatically returning along the original path or returning to the vehicle's current location according to a preset path plan.

7. The method according to claim 5, characterized in that, In step D, the repeater enters the working state in the following way: the repeater is already in the start-up state before being deployed to the designated location, and automatically starts scanning and matching the upstream device with the strongest signal after deployment is completed.

8. The method according to claim 5, characterized in that, In step E, the wireless frequency band used by the network coverage function activated by the repeater is different from the wireless coverage frequency band of the upstream base station or the upstream repeater.

9. The method according to claim 8, characterized in that, The upstream base station or upstream repeater uses the first frequency band N1 for coverage, and the repeater uses the second frequency band N2, which does not interfere with the first frequency band N1, for coverage.

10. The method according to claim 5, characterized in that, The designated deployment location in step C is determined based on the current vehicle location, the location of the previous level base station or the previous level repeater, and the signal attenuation model, so as to ensure that the backhaul link communication quality between the repeater and the previous level base station or the previous level repeater meets the preset requirements.

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