Underground coal mine wireless / wired converged communication system, method and equipment

Abstract

The invention provides an underground coal mine wireless / wired converged communication system, method and equipment, and relates to the technical field of mine communication and industrial internet. The method comprises the following steps: uniformly mapping LTE QCI, Wi-Fi and TSN flow through an intrinsic safety type edge fusion gateway IFG, realizing end-to-end deterministic scheduling based on 802.1 Qbv / 802.1 Qci / 802.1 CB, and starting FRER parallel transmission and short-period FEC for a key service to realize lt; and rapid protection switching of 50ms can be realized. A double-layer frequency division-multiplexing leaky coaxial cable and adaptive active equalization are provided, and the same-cable coverage and field intensity uniformity control of 4G and 5GHz Wi-Fi are realized. The system is suitable for coal mine underground voice, video, positioning, monitoring, control and other services, and has the advantages of low jitter, predictable time delay, high reliability, easy operation and maintenance and the like.

Description

Technical Field

[0001] This invention relates to the field of mining communication and industrial internet technology, and in particular to wireless / wired converged communication systems, methods and equipment for underground coal mines. Background Technology

[0002] Underground communication in coal mines generally adopts a hybrid network of "wired bearer + wireless access", but it has the following pain points: 1. Due to the complex electromagnetic and terrain conditions underground, a single wireless system is prone to fading, blind spots, and jitter in long tunnels, sharp bends, and multiple turning points. 2. Insufficient cross-bearer coordination between wired and wireless services makes it difficult to predict service handover / failure delays, affecting safe production functions such as voice, alarms, monitoring, and control. 3. LCX is commonly used in underground distributed antenna feeder systems, but there is insufficient coordination optimization of multiple standards (e.g., 4G@1.8 GHz and Wi-Fi@5 GHz) on the same cable and insufficient control of field strength uniformity along the line; The lack of unified end-to-end scheduling and the difficulty in integrating LTE QCI, Wi-Fi WMM, and wired QoS lead to fragmented operation and maintenance of multiple systems.

[0003] Therefore, a wireless / wired converged communication system, method, and device for underground coal mines are provided to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a wireless / wired converged communication system, method, and equipment for underground coal mines, enabling end-to-end low jitter, predictable latency, and fast protection switching of critical services at the <50 ms level; high consistency coverage and online equalization of 4G and 5 GHz Wi-Fi on the same cable (LCX); unified scheduling and slice isolation of LTE QCI, Wi-Fi WMM, and wired TSN networks; and predictive optimization and parallel traffic splitting based on roadway topology to reduce blind spots and congestion risks.

[0005] To achieve the above objectives, the present invention provides a wireless / wired converged communication system for underground coal mines, including a ground module, an underground bearer module, a wireless access module, an edge bearer module, and a terminal sensing module. The ground module integrates a converged scheduling and gateway platform, a 4G core network, an IMS system, and a clock source. The downhole support module includes a gigabit or 10-gigabit industrial ring network with dual redundancy (A / B), and the switching nodes have TSN functionality; The wireless access module includes 4G or Wi-Fi access methods. 4G access is achieved by distributed base stations and radio frequency units (RRUs) through a new type of double-layer frequency division-multiplexing leaky coaxial cable (DL-LCX) along the tunnel. Wi-Fi access uses Wi-Fi 6 or Wi-Fi 6E access points to cover the working face and chamber area. The edge bearer module deploys several intrinsically safe edge converged gateways, which connect to wired, 4G and Wi-Fi bearer networks respectively, and perform unified orchestration, clock relay, frame duplication and deduplication (FRER), forward error correction (FEC), policy scheduling and local computing (MEC) functions. The terminal sensing module includes an intrinsically safe 4G terminal, a Wi-Fi terminal, a camera, various sensors, PLC equipment, and personnel positioning tags.

[0006] Preferably, the scheduling and gateway platform includes an SDN controller and a TSN controller.

[0007] Preferably, the wireless access module uses a dual-layer frequency division-multiplexed leaky coaxial cable (DL-LCX) and an adaptive active equalizer. The same LCX segment performs layered slotting and coupling optimization for 4G and 5 GHz Wi-Fi, and the online equalization device compensates for frequency response and loss fluctuations along the line in real time.

[0008] Preferably, in the frame copying and deduplication FRER operation in the edge bearer module, FRER and short-cycle FEC are performed on the critical flows of alarm and control, supporting parallel transmission of "wired + 4G" or "wired + Wi-Fi", and automatic switching in less than 50 ms when the link deteriorates or the fiber breaks.

[0009] The communication method of a wireless / wired converged communication system in underground coal mines shall be implemented by following these steps: S1: The terminal accesses the intrinsically safe edge convergence gateway (IFG) via wired, 4G, or Wi-Fi. The IFG identifies and classifies packets based on the service 5-tuple or application identifier and establishes a flow table. S2: Service mapping and unified orchestration. The SDN / TSN controller maps various service flows to TSN flows, corresponding to the QCI category of LTE and the WMM priority of Wi-Fi, respectively, to achieve consistent scheduling and time slot allocation across bearers. S3: Clock distribution and synchronization. The PTP master clock of the ground module is sequentially distributed to the downhole switch and IFG through the wired ring network. The IFG then forwards the synchronization signal to the wireless access module to ensure that the end-to-end time error is within the sub-microsecond range. S4: Reliable transmission and error correction protection. FRER and short block long FEC mechanisms are enabled for critical service flows to achieve parallel transmission and error correction of wired and wireless services. Ordinary service flows are selected for single-bearer transmission based on the health score H(t) result. S5: Real-time monitoring and policy scheduling calculates the link health score H(t) every 100ms. The policy-aware scheduling PAS performs priority pre-allocation, bandwidth reallocation, and path optimization or parallel traffic splitting based on the status of the health score H(t) to ensure low jitter and stable latency for critical services. S6: Disaster recovery and rapid protection. When link degradation, fiber breakage or wireless coverage fading is detected, FRER parallel or primary / backup switching is triggered within a time window of T_pre=0.5s to achieve rapid switching in less than 50ms.

[0010] Preferably, the policy-aware scheduling (PAS) and health score H(t) specifically include the following steps: S51: Index normalization. Set the sampling period Δ=100ms and the sliding window W=3s. Normalize the observations (0=best, 1=worst) and calculate the health score H(t). In the formula, Indicates the packet error rate / packet loss rate. =min(PER / 0.05,1), the upper limit of the threshold is 5%, 0 = best, 1 = worst; Indicates shaking, =min( / 0.005,1), with a threshold of 5ms; Indicates PTP deviation. = my (| | / 0.0002,1), with a threshold of 200µs; This represents the excess loss relative to the link budget. = clip(( -Budget) / 6dB,0,1); 6dB range normalization. clip (x,0,1) indicates that the clipping is performed to the interval [0,1]. This indicates that the output queue is occupied. =Q len / Q max Q len ≤Q max Time naturally falls within [0,1]; This indicates the penalty for an SNR below a threshold. =max(0, - SNR ( / 10dB), =18dB, when SNR < Time > 0; This indicates the penalty for RSSI falling below a threshold. =max(0, - RSSI ( / 10dB), =-65dBm, when RSSI< Time > 0; Indicates a deterioration trend. = clip (-(dSNR / dt)·τ / 10dB,0,1), where dSNR / dt is the time derivative of SNR, and τ=3s; ; ; The update frequency is 10Hz, and median filtering and 3σ limiting are used to smooth out single outliers; S52: Based on the change in health score H(t), the network status is divided into four levels: robust, degraded, pre-switching, and failover, and a hysteresis threshold is set to prevent frequent switching. S53: In path selection and bandwidth allocation, a dynamic scoring model is established for each bearer path k∈Wired, 4G, and Wi-Fi: ; In the formula, B k Indicates the overall score of the path; Indicates the path health level (0~100); Indicates the current utilization rate (0~1); Indicates available bandwidth; This represents the cost or energy consumption; γ1~γ4 represent weighting coefficients, with values ​​of 0.5, 0.2, 0.2, and 0.1 respectively. The controller calculates the score of each load in real time. B k The path with the highest score is selected as the primary path. When FRER or dual-bearer protection is enabled for the service level, the path with the second highest score is selected as the backup path. S54: When the link health status changes, protection and recovery are performed according to the following timing sequence: When entering pre-switching A2, a backup bearer tunnel is pre-established and the encryption key and time slot table are synchronized. At the same time, bandwidth reallocation and priority pre-allocation are performed to prepare for the handover. When entering the A3 switchover phase, the FRER parallel or primary / backup link switchover is completed within the predetermined time window T_pre=0.5s to ensure that the service protection convergence time is less than 50ms. When a switchback is initiated, if the main link health score H > 85 and the continuous stable time is not less than T_probe = 2s, a switchback to the main link is triggered.

[0011] The underground wireless / wired converged communication equipment for coal mines includes an intrinsically safe edge converged gateway (IFG), an outer conductor geometry, radio frequency (RF) supporting equipment, an active equalization unit, and an independent power supply unit. The outer conductor geometry has two sets of slotted units with different periods and slot types arranged longitudinally. The RF supporting equipment includes segmented couplers, power dividers, and adjustable attenuators. The independent power supply unit supplies power to the active equalization unit. Intrinsically safe active equalization units are arranged along the line. The active equalization unit detects the VSWR and coupling loss in real time and automatically adjusts the gain to compensate for transmission attenuation, thus realizing the steps of the underground wireless / wired converged communication method for coal mines.

[0012] Preferably, the intrinsically safe edge convergence gateway (IFG) incorporates TSN acceleration, PTP boundary clock, FRER engine, and security slicing.

[0013] Preferably, the downhole carrier module supports at least IEEE 802.1Qbv, 802.1Qci, 802.1CB or IEEE 1588v2 hardware timestamps.

[0014] Therefore, the present invention employs the above-mentioned wireless / wired converged communication system, method, and equipment for underground coal mines, and the technical effects are as follows: (1) This invention reduces the end-to-end latency jitter of critical services by more than 60% compared with traditional 4G private networks through TSN scheduling, PTP synchronization and FRER parallel mechanism, and the protection switching time is less than 50 ms in the case of link degradation or fiber breakage, thus ensuring the continuity and predictability of real-time control services.

[0015] (2) The present invention provides single-cable multi-mode coverage, adopts double-layer frequency division-multiplexing LCX (DL-LCX) and adaptive active equalization to achieve high consistency coverage of 4G and 5 GHz Wi-Fi on the same cable, and controls the field strength difference along the line within ±3 dB. Compared with the traditional independent antenna feeder scheme, it saves about 40% of the wiring and is easier to maintain.

[0016] (3) The present invention unifies scheduling and slicing, realizes unified orchestration of LTE QCI, Wi-Fi WMM and wired TSN networks through IFG gateway, and forms an end-to-end deterministic converged network; different service slices are isolated from each other, independently limited in speed and guaranteed, solving the problems of multi-network fragmentation and uncontrollable latency.

[0017] (4) The edge fusion gateway of the present invention uses an independent power supply unit for power supply, explosion-proof structure and security slicing mechanism, taking into account both physical safety and logical protection, meeting coal mine safety standards and improving overall anti-interference and anti-attack capabilities.

[0018] (5) Based on the health score H(t) and the visualized topology, this invention realizes link status prediction and adaptive scheduling, supports remote calibration, abnormal alarm and automatic optimization, and significantly reduces manual maintenance and downtime risk. Detailed Implementation

[0019] The method of the present invention will be further described below through examples.

[0020] Unless otherwise defined, the methodological or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] The terms "comprising" or "including" as used in this invention mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements as well. The terms "inner," "outer," "upper," and "lower," indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this invention, unless otherwise explicitly specified and limited, the term "attached," etc., should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Example This invention provides a wireless / wired converged communication system for underground coal mines, including a ground module, an underground bearer module, a wireless access module, an edge bearer module, and a terminal sensing module. The ground module integrates a converged scheduling and gateway platform, a 4G core network, an IMS system, and a clock source. The underground bearer module includes a gigabit or 10-gigabit industrial ring network with A / B dual redundancy, and the switching nodes have TSN functionality; the underground bearer module supports at least IEEE 802.1Qbv, 802.1Qci, 802.1CB or IEEE 1588v2 hardware timestamps. The cross-bearer deterministic fusion mechanism (DMF) unifies the mapping and orchestration of LTE QCI, Wi-Fi and TSN streams (802.1Qbv / Qci / CB) to form end-to-end deterministic scheduling; The wireless access module includes 4G or Wi-Fi access methods. 4G access is achieved by distributed base stations and radio frequency units (RRUs) through a new type of double-layer frequency division-multiplexing leaky coaxial cable (DL-LCX) along the tunnel. Wi-Fi access uses Wi-Fi 6 or Wi-Fi 6E access points to cover the working face and chamber area. The edge bearer module deploys several intrinsically safe edge converged gateways, which connect to wired, 4G and Wi-Fi bearer networks respectively, and perform unified orchestration, clock relay, frame duplication and deduplication (FRER), forward error correction (FEC), policy scheduling and local computing (MEC) functions. The terminal sensing module includes an intrinsically safe 4G terminal, a Wi-Fi terminal, a camera, various sensors, PLC equipment, and personnel positioning tags.

[0023] The scheduling and gateway platform includes an SDN controller and a TSN controller.

[0024] The wireless access module uses a dual-layer frequency division-multiplexing leaky coaxial cable (DL-LCX) and an adaptive active equalizer. The same LCX segment performs layered slotting and coupling optimization for 4G and 5 GHz Wi-Fi, and the online equalization device compensates for frequency response and loss fluctuations along the line in real time.

[0025] In the frame duplication and deduplication FRER operation in the edge bearer module, FRER and short-cycle FEC are performed on the critical flows of alarm and control, supporting parallel transmission of "wired + 4G" or "wired + Wi-Fi", and automatic switching in less than 50 ms when the link deteriorates or the fiber breaks.

[0026] The communication method of a wireless / wired converged communication system in underground coal mines shall be implemented by following these steps: S1: The terminal accesses the intrinsically safe edge convergence gateway (IFG) via wired, 4G, or Wi-Fi. The IFG identifies and classifies packets based on the service 5-tuple or application identifier and establishes a flow table. S2: Service mapping and unified orchestration: The SDN / TSN controller maps various service flows to TSN flows, corresponding to the QCI category of LTE and the WMM priority of Wi-Fi, respectively, to achieve consistent scheduling and time slot allocation across bearers; Unified orchestration: The SDN / TSN controller issues time slot tables and policies according to service categories; IFG adds TSN Flow ID and sequence number to terminal packets to achieve consistent scheduling across domains.

[0027] S3: Clock distribution and synchronization. The PTP master clock of the ground module is sequentially distributed to the downhole switch and IFG through the wired ring network. The IFG then forwards the synchronization signal to the wireless access module to ensure that the end-to-end time error is within the sub-microsecond range. Clock synchronization: Surface PTP GM → Downhole switch (boundary / transparent clock) → IFG → wireless side timestamp; supports end-to-end sub-microsecond time synchronization accuracy (based on the line segment). S4: Reliable transmission and error correction protection. FRER and short block long FEC mechanisms are enabled for critical service flows to achieve parallel transmission and error correction of wired and wireless services. Ordinary service flows are selected for single-bearer transmission based on the health score H(t) result. S5: Real-time monitoring and policy scheduling calculates the link health score H(t) every 100ms. The policy-aware scheduling PAS performs priority pre-allocation, bandwidth reallocation, and path optimization or parallel traffic splitting based on the status of the health score H(t) to ensure low jitter and stable latency for critical services. The Policy-Aware Scheduling (PAS) and Health Score H(t) specifically include the following steps: S51: Index normalization. Set the sampling period Δ=100ms and the sliding window W=3s. Normalize the observations (0=best, 1=worst) and calculate the health score H(t). In the formula, Indicates the packet error rate / packet loss rate. =min(PER / 0.05,1), the upper limit of the threshold is 5%, 0 = best, 1 = worst; Indicates shaking, =min( / 0.005,1), with a threshold of 5ms; Indicates PTP deviation. = my (| | / 0.0002,1), with a threshold of 200µs; This represents the excess loss relative to the link budget. = clip(( -Budget) / 6dB,0,1); 6dB range normalization. clip (x,0,1) indicates that the clipping is performed to the interval [0,1]. This indicates that the output queue is occupied. =Q len / Q max Q len ≤Q max Time naturally falls within [0,1]; This indicates the penalty for an SNR below a threshold. =max(0, - SNR ( / 10dB), =18dB, when SNR < Time > 0; This indicates the penalty for RSSI falling below a threshold. =max(0, - RSSI ( / 10dB), =-65dBm, when RSSI < Time > 0; Indicates a deterioration trend. = clip (-(dSNR / dt)·τ / 10dB,0,1), where dSNR / dt is the time derivative of SNR, and τ=3s; ; ; The update frequency is 10Hz, and median filtering and 3σ limiting are used to smooth out single outliers; S52: Based on the change in health score H(t), the network status is divided into four levels: robust, degraded, pre-handover, and failover, as shown in Table 1, and a hysteresis threshold is set to prevent frequent handovers. Table 1

[0028] Corresponding action windows: T_pre=0.5s (pre-switching preparation), T_hold=5s (switching hold), T_probe=2s (probe-back). Business mapping strategy Level A alarm and control services are the highest priority services, requiring extremely high real-time performance and reliability. The system's strategy for each state is as follows: A0 / A1: Enable FRER dual-path parallel transmission (wired + 4G) to ensure zero packet loss of critical messages; A2: Enables three-way replication (wired + 4G + Wi-Fi) to achieve multi-bearer redundancy; A3: Maintain dual-bearer parallel links to prevent failover interruptions; always enable PTP reserved time slots and priority pre-emption mechanisms to ensure end-to-end deterministic latency.

[0029] Level B Voice and Dispatch Communication: A0: Single-bearer (optimal path) is adopted; A1: When the health score H(t) < 65, dual bearer (wired + 4G) will be automatically enabled. A2 / A3: Maintain dual-bearer parallel operation to ensure call continuity.

[0030] Level C video surveillance and image transmission, with adaptive bitrate to balance bandwidth and quality: A0: Single-bearer transmission, automatic bitrate adjustment; A1: Bitrate reduced by approximately 30%; A2: Reduce the bitrate by about 50% and establish a backup path; A3: Switch to the backup bearer to continue transmission.

[0031] Level D detection and telemetry data: A0: Normal transmission; A1: Merge and upload in batches to reduce frequency; A2: Delay transmission to an idle period or switch to a low-speed narrowband channel; A3: Suspend transmission (except for whitelisted critical nodes).

[0032] S53: In path selection and bandwidth allocation, a dynamic scoring model is established for each bearer path k∈Wired, 4G, and Wi-Fi: ; In the formula, B k Indicates the overall score of the path; Indicates the path health level (0~100); Indicates the current utilization rate (0~1); Indicates available bandwidth; This represents the cost or energy consumption; γ1~γ4 represent weighting coefficients, with values ​​of 0.5, 0.2, 0.2, and 0.1 respectively. The controller calculates the score of each load in real time. B k The highest-scoring path is selected as the primary path, and when FRER or dual-bearer protection is enabled for the service level, the second-highest-scoring path is selected as the backup path. This scoring model takes into account both link health and real-time load, and can achieve multi-bearer optimal scheduling with "stability priority, bandwidth consideration, and controllable energy consumption".

[0033] S54: When the link health status changes, protection and recovery are performed according to the following timing sequence: When entering pre-switching A2, a backup bearer tunnel is pre-established and the encryption key and time slot table are synchronized. At the same time, bandwidth reallocation and priority pre-allocation are performed to prepare for the handover. When entering the A3 switchover phase, the FRER parallel or primary / backup link switchover is completed within the predetermined time window T_pre=0.5s to ensure that the service protection convergence time is less than 50ms. When a switchback is initiated, if the main link health score H > 85 and the continuous stable time is not less than T_probe = 2s, a switchback to the main link is triggered.

[0034] S6: Disaster recovery and rapid protection. When link degradation, fiber breakage, or wireless coverage fading is detected, FRER parallel or primary / backup switching is triggered within a time window of T_pre=0.5s, achieving rapid failover in less than 50ms to ensure service continuity and system determinism. The bearer link, IFG, power supply, and controller all adopt 1+1 redundancy; critical nodes support A / B dual rings and link self-healing.

[0035] The underground wireless / wired converged communication equipment for coal mines includes an intrinsically safe edge converged gateway (IFG), an outer conductor geometry, RF supporting equipment, an active equalization unit, and an independent power supply unit. The intrinsically safe edge converged gateway (IFG) incorporates TSN acceleration, PTP boundary clock, FRER engine, and security slicing. The outer conductor geometry features two sets of slotted units with different periods and slot shapes along the longitudinal direction, optimizing coupling performance for cellular frequency bands (e.g., 1.8 GHz / 2.1 GHz) and the 5 GHz Wi-Fi band, respectively. The RF supporting equipment includes segmented couplers, power dividers, and adjustable attenuators to achieve fine-grained signal power distribution. The independent power supply unit powers the active equalization unit and features bypass switching and remote upgrade capabilities, facilitating fault isolation and maintenance. Intrinsically safe active equalization units are deployed along the line. These units monitor VSWR and coupling loss in real time and automatically adjust gain to compensate for transmission attenuation, thus implementing the steps of the underground wireless / wired converged communication method for coal mines.

[0036] Intrinsically safe edge convergence gateway IFG Interfaces: ≥2×SFP (1 / 10GbE), 1×cellular 4G RF / USIM, ≥2×Wi-Fi RF (can be 2×2 / 4×4MIMO); Time and Determinism: IEEE 1588v2 hardware timestamp, PTP boundary clock; TSN acceleration unit (Qbv / Qci / CB); FRER engine and short block length FEC; Processing and storage: ARM SoC + FPGA / ASIC; On-chip security unit, TCAM flow table; Intrinsic safety and power supply: Redundant intrinsically safe power supply; supports intrinsically safe PoE-bt downstream power supply; Environment: Dustproof, moisture-proof and impact-resistant design to meet downhole temperature / humidity / vibration requirements.

[0037] Therefore, this invention employs the aforementioned wireless / wired converged communication system, method, and equipment for underground coal mines. By establishing a state-space prediction model for the system and combining multi-step prediction, rolling optimization, and feedback correction mechanisms, the optimal control command is solved online, thereby effectively suppressing frequency deviations caused by photovoltaic fluctuations and load disturbances, and improving system stability and power quality.

[0038] Example 1 The preferred distance between a single ring of the ring network is no more than 20km, and the distance between nodes is 300–1000m; The preferred deployment spacing for edge convergence gateways (IFG) is 600–800m, which can be adjusted appropriately depending on the lane attenuation and service density. The segment length of the double-layer frequency division-multiplexed LCX (DL-LCX) is 1–2km, and the field strength uniformity along the line is controlled within ±3dB (5–95 percentile). The performance targets for different business categories are as follows: Alarm and control services: end-to-end latency P95 ≤ 30ms, switching / protection convergence time < 50ms; Voice services: Packet loss rate <1%, Subjective speech quality (MOS) ≥3.5; Video services: Supports 1080p@30fps, adaptive bitrate 2–6Mbps; The system's end-to-end time synchronization accuracy is: time synchronization error on the line segment ≤ 1µs, and timestamp deviation P95 on the wireless side ≤ 200µs; The operating ambient temperature range is -20℃ to +45℃, the relative humidity is ≤95%, and the power supply is a 24VDC intrinsically safe power supply.

[0039] The above parameters are non-limiting and can be adaptively adjusted according to the mine size and communication requirements.

[0040] Specifically deployed in the vertical shaft—transport main roadway—coal mining face. Ground module: Dual data center architecture, deploying PTP master clock (Grandmaster) and SDN / TSN controller to achieve unified clock and policy distribution; Downhole support module: adopts A / B dual-ring industrial Ethernet, with a node spacing of 300-800m, and intrinsically safe edge convergence gateway (IFG) and LCX equalization unit are configured in key roadway sections; Wireless access module: 4G signal is leaked along the alleyway via BBU→RRU→DL-LCX, and the field strength is enhanced by a encrypted coupling structure in the bend and intersection areas; Wi-Fi 6 / 6E access points (APs) are deployed at intervals of 80–120m, and compensation is provided in blind spots using directional antennas or LCX couplers; Business diversion strategy: The alarm and control services adopt a parallel redundant bearer of "wired + 4G"; Voice services will primarily utilize 4G, with wired connections as a backup. Video services are primarily wired, with Wi-Fi as a backup.

[0041] IFG adopts a "hardware deterministic + software policy control" architecture: Hardware layer (FPGA / ASIC): Implements TSN gated scheduling (802.1Qbv) and frame duplication / deletion mechanism (802.1CBFRER), and provides hardware-level timestamps to support PTP synchronization; Software layer: Implements flow table distribution, PTP boundary clock management, FEC encoding / decoding, and policy-aware scheduling (PAS) algorithm execution; Security features: Supports whitelist / blacklist filtering, slice isolation, and multicast suppression; Intrinsically safe design: power limiting, signal isolation and explosion-proof enclosure, in compliance with coal mine intrinsic safety standards.

[0042] Implementation of Dual-Layer Frequency Division-Multiplexing LCX (DL-LCX) and Online Equalization The outer conductor of the DL-LCX has two sets of slotted structures with different periods along the longitudinal direction, which are respectively matched with the coupling characteristics of the cellular (1.8–2.1GHz) and Wi-Fi (5GHz) frequency bands to realize multi-system transmission on the same cable.

[0043] The equalization unit collects VSWR and coupling loss data in real time, and dynamically compensates for frequency response and insertion loss along the line based on PID / model prediction algorithm to ensure that field strength uniformity is controlled within ±3dB.

[0044] The maintenance unit supports remote upgrades and bypass switching, facilitating downhole maintenance. The PAS module collects link metrics (RSSI, SNR, PER, ΔPTP, queue occupancy, LCX loss, etc.) every 100ms period and calculates the health score H(t).

[0045] When H(t) is below the set threshold or the prediction model determines that it will drop to the risk range within T=1–5s, the system triggers priority pre-occupancy and bandwidth reallocation, and automatically decides based on the service level: whether to enable FRER parallel transmission; whether to adjust the bearer selection (wired, 4G, Wi-Fi); whether to reduce the bit rate or suspend low-priority services.

[0046] Therefore, this invention employs the aforementioned wireless / wired converged communication system, method, and equipment for underground coal mines. It achieves end-to-end deterministic scheduling based on 802.1Qbv / 802.1Qci / 802.1CB, and enables FRER parallel transmission and short-cycle FEC for critical services to achieve rapid protection switching of <50 ms. A dual-layer frequency division-multiplexed leaky coaxial cable and adaptive active equalization are proposed to achieve co-cable coverage and field strength uniformity control for 4G and 5 GHz Wi-Fi. It is suitable for voice, video, positioning, monitoring, and control services in underground coal mines, and possesses advantages such as low jitter, predictable latency, high reliability, and easy maintenance.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A coal mine wireless / wired fusion communication system, characterized in that, The system comprises a ground module, a downhole bearing module, a wireless access module, an edge bearing module and a terminal sensing module, the ground module integrates a fusion scheduling and gateway platform, a 4G core network, an IMS system and a clock source; The downhole bearing module comprises a gigabit or megabit industrial ring network with A / B dual redundancy, and the switching node has TSN function; The wireless access module comprises 4G or Wi-Fi access mode, the 4G access is realized by a distributed base station and a radio frequency unit RRU along the roadway through a new type of double-layer frequency division-multiplexing leaky coaxial cable DL-LCX to achieve coverage; the Wi-Fi access adopts a Wi-Fi 6 or Wi-Fi 6E access point to cover the working face and chamber area; The edge bearing module is provided with a plurality of intrinsic safety edge fusion gateways, which are respectively connected with three types of bearing networks including wired, 4G and Wi-Fi, and perform unified arrangement, clock relay, frame replication and deduplication FRER, forward error correction FEC, policy scheduling and local computing MEC functions; In the terminal sensing module, there are intrinsic safety 4G terminals, Wi-Fi terminals, cameras, various sensors, PLC equipment and personnel positioning tags.

2. The coal mine underground wireless / wired converged communication system of claim 1, wherein, The scheduling and gateway platform comprises an SDN controller and a TSN controller.

3. The coal mine underground wireless / wired converged communication system according to claim 2, characterized in that, In the wireless access module, the double-layer frequency division-multiplexing leaky coaxial cable DL-LCX and adaptive active equalization are used, the same LCX segment is layered and slotted and coupled to optimize 4G and 5 GHz Wi-Fi, and an online equalization device compensates for frequency response and loss fluctuation along the line in real time.

4. The coal mine underground wireless / wired converged communication system of claim 3, wherein, In the frame replication and deduplication FRER operation in the edge bearing module, FRER and short cycle FEC are performed on key flows of alarm and control, parallel transmission of "wired + 4G" or "wired + Wi-Fi" is supported, and link degradation and fiber breakage are automatically switched within <50 ms.

5. The communication method of the coal mine underground wireless / wired fusion communication system according to any one of claims 1-4, characterized in that, The following steps are performed: S1: The terminal accesses an intrinsic safety edge fusion gateway IFG through wired, 4G or Wi-Fi, the IFG identifies and classifies messages according to service five-tuple or application identifier, and establishes a flow table; S2: Service mapping and unified arrangement, the SDN / TSN controller maps various service flows into TSN flows, which correspond to LTE QCI categories and Wi-Fi WMM priorities respectively, to realize consistent scheduling and time slot allocation across bearers; S3: Clock distribution and synchronization, the PTP master clock of the ground module is sequentially distributed to downhole switches and IFGs through a wired ring network, and the IFG forwards the synchronization signal to the wireless access module, to ensure that the end-to-end time error is within the sub-microsecond range; S4: Reliable transmission and error correction protection, FRER and short block FEC mechanisms are enabled for key service flows to realize "wired + wireless" parallel transmission and error correction; ordinary service flows are transmitted by single bearing transmission according to the health score H(t) result; S5: Real-time monitoring and policy scheduling, the link health score H(t) is calculated at a period of 100 ms, and the priority preemption, bandwidth reallocation, path optimization or parallel shunting are performed according to the state of the health score H(t) by the policy-aware scheduling PAS, to ensure low jitter and stable time delay of key services. S6: Disaster recovery and fast protection, when link degradation, fiber break or wireless coverage fading is detected, trigger FRER parallel or active-standby switching within a time window of T_pre=0.5s, realize less than 50ms fast switching.

6. The coal mine underground wireless / wired fusion communication method according to claim 5, characterized in that, In step S5, the policy-aware scheduling PAS and the health score H(t) specifically include the following steps: S51: Index normalization, set the sampling period Δ=100ms and the sliding window W=3s, normalize the observation (0=best, 1=worst), and calculate the health score H(t); wherein denotes the data packet error / loss rate, =min(PER / 0.05,1), threshold upper limit 5%, 0=best, 1=worst; denotes the jitter, =min( / 0.005,1), threshold 5ms; denotes the PTP deviation, = min (|dPTP / dt|>0.5) / 0.5,1) | / 0.0002,1), threshold 200µs; denotes the excess loss relative to the link budget, = clip(( -Budget) / 6dB,0,1); 6dB range normalized, clip (x,0,1) denotes clipping to the interval [0,1]; denotes the output queue occupancy, =Q len / Q max , Q len ≤Q max is naturally in [0,1]; denotes the penalty for SNR below threshold, =max(0, - SNR ) / 10dB), =18dB, when SNR < >0; denotes the penalty for RSSI below threshold, =max(0, - RSSI ) / 10dB), =-65dBm, when RSSI < >0; denotes the degradation trend, = clip (-(dSNR / dt)·τ / 10dB,0,1), where dSNR / dt is the time derivative of SNR and τ=3s; ； ； The update frequency is 10Hz, and the single abnormal value is smoothed by median filtering and 3σ limiting method; S52: According to the change of health score H(t), the network state is divided into four levels of robust, degenerative, pre-switching and switching, and a hysteresis threshold is set to prevent frequent switching; S53: In path selection and wideband allocation, a dynamic scoring model is established for each bearing path k∈ wired, 4G, Wi-Fi: ； In the formula, B k represent the comprehensive score of the path; represent the path health degree (0~100); represent the current utilization rate (0~1); represent the available bandwidth; represent the cost or energy consumption cost; γ1~γ4 represent the weight coefficients, and the values are 0.5, 0.2, 0.2, and 0.1 respectively; The controller calculates the score of each bearer in real time B k The path with the highest score is selected as the main path, and the path with the second highest score is selected as the backup path when the service level enables FRER or dual-bearer protection. S54: When the link health state changes, protection and recovery are performed according to the following timing: When entering pre-switching A2, the standby bearing tunnel is established in advance and the encryption key and time slot table synchronization are completed, and the bandwidth reallocation and priority pre-occupation are performed to prepare for switching; When entering switching A3, complete FRER parallel or active-standby link switching within a predetermined time window T_pre=0.5s, ensure that the service protection convergence time is less than 50ms; When entering back switching, the main link health score H>85 and the continuous stable time is not less than T_probe=2s, trigger back switching to the main road.

7. A coal mine underground wireless / wired converged communication device, characterized in that, The intrinsically safe edge fusion gateway IFG, the outer conductor geometry, the radio frequency matching equipment, the active equalization unit and the independent power supply unit are included; the outer conductor geometry is provided with two groups of slotted units with different periods and slot types along the longitudinal direction, the radio frequency matching equipment includes a segmented coupler, a power divider and an adjustable attenuator; the independent power supply unit supplies power to the active equalization unit, the intrinsically safe active equalization unit is arranged along the line, the active equalization unit detects the standing wave ratio and the coupling loss in real time, and automatically adjusts the gain to compensate for transmission attenuation, thereby realizing the steps of the coal mine underground wireless / wired fusion communication method as claimed in any one of claims 5-6.

8. The coal mine underground wireless / wired convergence communication device according to claim 7, characterized in that, The intrinsically safe edge fusion gateway IFG is built-in TSN acceleration, PTP boundary clock, FRER engine and security slice.

9. The coal mine underground wireless / wired converged communication system of claim 1, wherein, The underground bearing module at least supports IEEE 802.1Qbv, 802.1Qci, 802.1CB or IEEE 1588v2 hardware timestamp. The intrinsically safe edge fusion gateway IFG is built-in TSN acceleration, PTP boundary clock, FRER engine and security slice. The underground bearing module at least supports IEEE 802.1Qbv, 802.1Qci, 802.1CB or IEEE 1588v2 hardware timestamp.

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