VoIP-based coal mine converged communication method and system

Abstract

The invention relates to a coal mine converged communication method and system based on VoIP, and belongs to the technical field of coal mine communication. In order to solve the problem of information isolated island caused by the fact that protocols of existing coal mine dispatching communication, wireless communication and emergency broadcasting systems are not compatible, services are mutually independent, unified dispatching cannot be achieved and video calls are not supported, an underground 10-gigabit Ethernet looped network and a WIFI wireless network are constructed; based on a FreeSWITCH soft switch server, unified registration management of equipment such as a broadcast terminal, an anti-explosion mobile phone and an SIP voice miner lamp is achieved, a standard SIP protocol, a WebRTC technology and a voice gateway are adopted to achieve wired and wireless terminal multi-protocol audio and video fusion intercommunication and video call functions, and emergency broadcast, timing broadcast and multi-system emergency linkage are provided. Information islands are thoroughly broken through, deep fusion of a coal mine communication system is realized, and the dispatching command efficiency, the call quality and the emergency rescue response capability are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of coal mine communication technology, and relates to a VoIP-based coal mine converged communication method and system. Background Technology

[0002] Coal mine communication systems mainly include dispatch communication systems, wireless communication systems, and emergency broadcasting systems. They are crucial tools for coal mine safety production dispatching, safety avoidance, and emergency rescue. Currently, the communication dispatch system uses the traditional PSTN communication protocol to achieve voice communication between fixed telephones; the wireless communication system is based on the UDP protocol and uses SIP communication technology to achieve point-to-point communication between wireless terminals; the emergency broadcasting system uses CAN bus communication technology to achieve voice intercom and audio data playback functions between broadcasting terminals.

[0003] Currently, the three systems in coal mines—dispatch communication, wireless communication, and emergency broadcasting—use various incompatible communication protocols, operate independently, and are technically incompatible. This results in limited data sharing and interoperability among the three systems, difficulties in unified dispatch and command, insufficient system integration capabilities, and a lack of support for video calls. Furthermore, the coexistence of old and new networks and the parallel management of multiple systems are common, with Ethernet, CAN, SIP, and other protocols mixed together, leading to low equipment integration and the formation of communication "information silos."

[0004] In response to the aforementioned defects and shortcomings of existing communication systems, this invention primarily addresses the following issues: the three major communication systems cannot be integrated in terms of architecture; they cannot interconnect and coordinate unified scheduling and command in terms of services; they cannot achieve unified management of wired and wireless terminals in terms of equipment management; they cannot achieve multi-protocol converged communication in terms of functionality; and they do not support video calls. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a VoIP-based coal mine converged communication method and system. Through the overall architecture of the converged communication system, it integrates the underground ring network and WIFI wireless network in the coal mine. Based on FreeSWITCH softswitch service, it achieves unified registration management and status monitoring of terminal devices such as broadcast terminals, explosion-proof mobile phones, and voice-activated mine lamps. It adopts standard SIP communication technology to achieve interconnection and interoperability between wired terminals and wireless devices; it employs voice gateway technology to achieve converged communication of PSTN and SIP protocols; it uses multi-protocol hybrid communication technology to achieve voice interoperability between SIP and CAN bus; and it uses WebRTC technology to enable video calls between video terminals. This solves the "information silo" problem existing in traditional communication modes in coal mines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A VoIP-based coal mine converged communication method includes the following steps performed sequentially: The underground roadway network is fully covered by a 10 Gigabit Ethernet ring network and a WIFI wireless network, and broadcast terminals, explosion-proof mobile phones, and SIP voice mining lamps are all connected to the converged communication server. All terminal devices complete unified registration and status monitoring on the FreeSWITCH softswitch server via the standard SIP protocol; Based on the FreeSWITCH softswitch server, the SIP protocol, Real-time Transport Protocol (RTP) and WebRTC technologies are used to realize voice and video calls between wired and wireless terminals, wherein the voice and video calls include voice codec and video codec. The SIP protocol and PSTN protocol are converted through a voice gateway, thereby enabling voice communication between the SIP terminal and the underground PSTN fixed telephone. Voice interoperability between SIP protocol and CAN bus protocol is achieved through multi-protocol conversion; The application-layer web front-end provides unified dispatch and command, emergency broadcasting, scheduled broadcasting, device management, call record query, and emergency linkage with external systems.

[0007] Furthermore, after the voice or video call is initiated, it also includes: The call center sends an INVITE request to the called terminal through the FreeSWITCH softswitch server and automatically selects SIP, H.323 or WebRTC protocol to establish a session based on the type of the called terminal. After the called terminal returns 200 OK, the call center and the called terminal negotiate the selection of audio and video codecs and network connection parameters through the Session Description Protocol (SDP). The audio and video media streams are transmitted via UDP using the real-time transmission protocol, and the session signaling is transmitted using TCP or WebSocket.

[0008] Furthermore, in the low-bandwidth scenario underground, the voice encoding and decoding adopts G.711a / u encoding; In high-definition voice or video call scenarios, the voice codec uses OPUS encoding, and the video codec uses H.264 encoding or VP9 encoding. The audio and video media streams are transmitted in encrypted form using the Secure Real-time Transport Protocol (SRTP).

[0009] Furthermore, the communication method also includes an emergency broadcast step: The dispatch console selects unicast mode, multicast mode, or mine-wide broadcast mode, and sends broadcast instructions to the selected broadcast terminals; After receiving the broadcast instruction, the broadcast terminal interrupts the current task to broadcast with the highest priority, and the converged communication server records the broadcast content and stores the broadcast record.

[0010] Furthermore, the communication method also includes a timed broadcasting step: Pre-set broadcast plans, including start time, end time, track list, and target broadcast terminal list; The converged communication server automatically performs timed broadcasts at the start time and performs volume enhancement processing after converting PDF or Word documents into standardized mp3 audio files.

[0011] Furthermore, the communication method also includes an emergency response step: The converged communication server receives alarm commands from security monitoring systems, personnel positioning systems, or AI video recognition systems via a standard WebAPI interface. The converged communication server automatically triggers the broadcast terminal in the corresponding area to execute the highest priority alarm broadcast based on the alarm command.

[0012] Furthermore, during the transmission of the audio and video media stream, when the packet loss rate reported by the Real-time Transport Control Protocol (RTCP) is greater than 5%, the FreeSWITCH softswitch server triggers a forward error correction mechanism or reduces the video bitrate. When the latency reported by the RTCP is greater than 300ms, the FreeSWITCH softswitch server enables jitter buffering or switches to a TURN (Traversal Using Relays around NAT) relay.

[0013] A VoIP-based coal mine converged communication system includes a system infrastructure module and a converged communication software module; The system infrastructure modules include an underground 10 Gigabit Ethernet ring network, a WIFI6 wireless network, a ground core switch, an underground core switch, a wireless base station, a broadcast terminal, explosion-proof mobile phones, SIP voice mining lamps, a voice gateway, PSTN fixed phones, and a converged communication server. The broadcast terminal is connected to the underground core switch via optical fiber. The explosion-proof mobile phones and SIP voice mining lamps are connected to the underground core switch via the wireless base station. The underground core switch is connected to the ground core switch via an optical fiber ring network. The voice gateway performs the conversion between SIP and PSTN protocols. The converged communication software module is deployed on the converged communication server and includes a hardware access layer, a data transmission layer, a core service support layer, and an application function layer. All terminal devices achieve unified registration management and status monitoring on the FreeSWITCH softswitch server through the standard SIP protocol. The core service support layer realizes audio and video converged communication between terminals with different protocols through the FreeSWITCH softswitch server, WebRTC technology, and the voice gateway.

[0014] 9. Furthermore, the core service support layer includes the FreeSWITCH softswitch server, the voice gateway, a multi-protocol conversion module, a status monitoring module, and an audio / video encoding / decoding module. The multi-protocol conversion module realizes real-time voice data conversion between SIP protocol and CAN bus protocol.

[0015] Furthermore, the application function layer includes a communication scheduling module, an emergency broadcasting module, a timed broadcasting module, an equipment management module, a report query module, and a GIS single-map module. The GIS single-map module displays the location of underground terminal equipment and personnel on a geographic information system graphic and supports initiating audio and video calls directly from the geographic information system graphic to the terminal equipment.

[0016] Furthermore, the hardware access layer supports TCP, UDP and CAN bus protocols to establish long-term connections with downhole hardware devices, and the data transmission layer uploads data to the converged communication server in real time through the downhole 10 Gigabit Ethernet ring network and the WIFI6 wireless network.

[0017] Furthermore, the converged communication software module is developed based on the .NET 8.0 framework using the MVC pattern. The system software architecture of the converged communication software module is divided into the application function layer, service layer, data transmission layer, and hardware access layer from top to bottom.

[0018] The beneficial effects of this invention are as follows: This invention, by constructing a unified converged communication architecture, completely breaks down the information silos between the original dispatch communication system, wireless communication system, and emergency broadcasting system, and achieves deep integration of the three systems in terms of architecture, business, and equipment management, significantly improving the uniformity of overall communication and dispatching efficiency in coal mines.

[0019] This invention registers all wired and wireless terminals to the FreeSWITCH softswitch server for management and status monitoring, achieving seamless interconnection and interoperability between wired and wireless devices, and solving the prominent problems of incompatibility and inability to manage in a unified manner in traditional systems.

[0020] This invention introduces WebRTC technology to enable video calls between devices such as broadcast terminals, explosion-proof mobile phones, and SIP voice mining lamps, making up for the lack of video communication capabilities in existing coal mine communication systems and providing important support for visual scheduling and emergency command in complex underground environments.

[0021] This invention achieves real-time integration and interoperability of SIP protocol with PSTN protocol and CAN bus protocol through voice gateway and multi-protocol conversion module, ensuring smooth transition and compatible coexistence of new and old systems and equipment.

[0022] This invention features targeted designs in audio and video encoding and decoding, media transmission, routing and forwarding, and network quality optimization. It effectively overcomes the problems of large jitter, high packet loss rate, severe latency, and large noise echo in underground networks, significantly improving call clarity, image quality, and communication stability, and achieving low-latency, high-quality audio and video fusion communication.

[0023] This invention provides a standard WebAPI interface, enabling deep emergency linkage with safety monitoring systems, personnel positioning systems, AI video recognition systems, geographic information systems, etc. When a dangerous situation occurs, it can automatically trigger the highest priority alarm broadcast and dispatch instructions, which greatly improves the response speed and handling efficiency of coal mine emergency rescue.

[0024] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is the overall system design diagram; Figure 2 For software architecture design diagrams; Figure 3 For software business process diagrams; Figure 4 This is a flowchart of the VoIP communication process. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0028] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0029] Figure 1 This is the overall system design diagram of the present invention. (See diagram below.) Figure 1As shown, the overall system architecture is divided into a surface section and an underground section. The surface section mainly includes a converged communication server, a surface core switch, a dispatch console, multi-function telephones, a voice gateway, and microphone speakers. The underground section is connected to the surface via a 10 Gigabit fiber optic ring network, and its main equipment includes an underground core switch, wireless base stations, broadcast terminals, explosion-proof mobile phones, SIP voice mining lamps, broadcast speakers, and LED displays. The converged communication server is located at the surface center and is used to centrally process all communication services; the surface core switch and the underground core switch are connected via a fiber optic ring network to achieve high-speed data transmission; the broadcast terminals are connected to the underground core switch via fiber optics; the explosion-proof mobile phones and SIP voice mining lamps are connected to the network via wireless base stations; the voice gateway connects to the existing PSTN fixed telephones; all data ultimately converges to the converged communication server.

[0030] Figure 2 This is a software architecture design diagram for the present invention. (See diagram below.) Figure 2 As shown, the converged communication software module adopts a layered design, consisting of an application layer, a service layer, a transport layer, and a hardware layer from top to bottom. The application layer implements user interface interaction and business function presentation, including a scheduling interface, a broadcast management interface, and a report query interface. The service layer contains a FreeSWITCH softswitch server, a multi-protocol conversion module, and a status monitoring module, responsible for core communication processing. The transport layer is responsible for real-time data upload to the underground ring network and the WIFI6 network. The hardware layer supports multiple protocols such as TCP, UDP, and CAN bus access. Layers interact with each other loosely through standard interfaces, ensuring high system cohesion and high scalability.

[0031] Figure 3 This is a business process diagram of the system of this invention. For example... Figure 3 As shown, the overall business process starts with device access, proceeds through registration, parsing, session establishment, media transmission, and application function implementation. The process first establishes a device connection via Socket, then transmits data to the server via the underground network to complete registration and parsing. Next, FreeSWITCH handles the audio and video sessions, and finally, the application layer provides broadcast, scheduling, and emergency response functions, and integrates with other systems through external WebAPI interfaces.

[0032] Figure 4 This is a flowchart illustrating the VoIP communication process of this invention. Figure 4 As shown, the entire process from session initiation to call termination is illustrated in detail. The process includes call center session initiation, protocol adaptation and registration verification, SDP capability negotiation, audio and video encoding and decoding processing, RTP / RTCP media transmission, NAT traversal and routing forwarding, as well as call termination and resource release.

[0033] Example 1 This embodiment was deployed and applied in a large-scale modern coal mine with an annual output of 3 million tons. The mine has achieved full coverage of a 10-gigabit ring network and WIFI6 signal without dead zones. It currently has 120 PSTN fixed telephones, 220 broadcast terminals supporting the SIP protocol, 200 explosion-proof mobile phones, 280 SIP voice mining lamps, and 80 LED displays.

[0034] After deployment, all terminal devices complete unified registration and real-time online status monitoring on the FreeSWITCH softswitch server via the standard SIP protocol. The daily scheduling and communication workflow is as follows: The ground dispatch console selects a single call or group call target through the web front end. For example, to call the SIP voice mine lamp in the -350m horizontal transport roadway underground, after the dispatch console clicks the call button, the call center sends an INVITE request to the FreeSWITCH softswitch server.

[0035] FreeSWITCH checks the registration status of the called terminal. After confirming that it is online, it pushes INVITE to the SIP voice mining lamp. The called terminal rings and returns 180 Ringing. After answering, it returns 200 OK.

[0036] Both parties negotiated through SDP to select OPUS encoding (for high-definition scenarios) or G.711 encoding (for low-bandwidth areas), and the media stream was encrypted using SRTP and then transmitted in real time via RTP / UDP.

[0037] During the call, RTCP provides real-time feedback on network quality. When the packet loss rate exceeds 5%, it automatically triggers forward error correction and reduces the bit rate. When the latency exceeds 300ms, it enables jitter buffering or switches to TURN relay to ensure clear and smooth calls in the complex underground network environment.

[0038] When the call ends, one party sends BYE, and the other party replies with 200 OK. FreeSWITCH then releases resources and logs the call.

[0039] This embodiment fully realizes unified registration of wired and wireless terminals and high-quality audio and video communication using multiple protocols.

[0040] Example 2 In this embodiment, the system focuses on verifying emergency broadcasting and multi-system emergency linkage functions. The mine has already been connected to a safety monitoring system, a personnel positioning system, and an AI video recognition system.

[0041] When the underground gas sensor triggers an over-limit alarm, the workflow is as follows: The security monitoring system pushes alarm commands to the converged communications server through the standard WebAPI interface. The commands include the alarm location, type, and level.

[0042] After the converged communication server parses the command, it automatically triggers the highest priority emergency broadcast plan and selects all broadcast terminals in the alarm area and adjacent areas (multicast mode).

[0043] FreeSWITCH pushes a broadcast media stream to the selected broadcast terminal. The broadcast terminal immediately interrupts its current task and forcibly plays the voice message "Gas in a certain area exceeds the limit. Please evacuate to a safe location immediately." At the same time, the LED display shows a scrolling text alarm.

[0044] The system records and stores the entire broadcast, the personnel positioning system displays the evacuation route in real time, and the dispatch console can directly see the distribution of personnel around the alarm point through the GIS map module, and can initiate a video call with one click to confirm the situation on site.

[0045] Once the emergency is over, the dispatch center will manually or automatically issue a command to cancel the broadcast.

[0046] This embodiment achieves the highest priority emergency broadcast and deep linkage of multiple systems.

[0047] Example 3 This embodiment verifies the timed broadcast and video call functions.

[0048] The system automatically broadcasts safety education audio and pre- and post-shift instructions at 7:30 AM and 7:00 PM daily. The specific procedure is as follows: Administrators can set up a scheduled plan in advance on the web front end, upload a secure Word or PDF file, and the system will automatically convert it into a standardized MP3 and perform volume enhancement processing.

[0049] Once the set time is reached, the converged communication server automatically pushes the audio stream to all broadcast terminals in the mine, enabling synchronized playback throughout the mine.

[0050] Meanwhile, when the dispatch console needs to conduct video calls with a broadcast terminal equipped with a camera: The dispatch console can directly click the broadcast terminal icon on a GIS map to initiate a video call.

[0051] The system establishes sessions using WebRTC technology, employs VP9 video encoding and OPUS audio encoding, and transmits media streams encrypted via SRTP.

[0052] Dispatchers can see the real-time footage from the mine and guide rescue or production operations.

[0053] This embodiment realizes intelligent scheduling of timed broadcasts and visual scheduling of video calls.

[0054] Example 4 This embodiment verifies the integration and interoperability with traditional PSTN fixed telephones and CAN bus broadcast terminals.

[0055] The existing PSTN fixed-line telephones within the mine will continue to be used, and the workflow is as follows: When an explosion-proof mobile phone dials a landline number, the call request reaches FreeSWITCH.

[0056] FreeSWITCH uses a voice gateway to convert SIP signaling to PSTN signaling, achieving seamless protocol conversion.

[0057] Traditional CAN bus broadcast terminals connect via a multi-protocol conversion module, where voice data is converted into SIP / RTP format in real time to participate in group calls or intercoms.

[0058] This implementation ensures a smooth transition between the old and new systems.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A VoIP-based coal mine converged communication method, characterized in that: The following steps are performed sequentially: The underground roadway network is fully covered by a 10 Gigabit Ethernet ring network and a WIFI wireless network, and broadcast terminals, explosion-proof mobile phones, and SIP voice mining lamps are all connected to the converged communication server. All terminal devices complete unified registration and status monitoring on the FreeSWITCH softswitch server via the standard SIP protocol; Based on the FreeSWITCH softswitch server, the SIP protocol, Real-time Transport Protocol (RTP), and WebRTC technologies are used to realize voice and video calls between wired and wireless terminals, wherein the voice and video calls include voice encoding and decoding and video encoding and decoding. The SIP protocol and PSTN protocol are converted through a voice gateway, thereby enabling voice communication between the SIP terminal and the underground PSTN fixed telephone. Voice interoperability between SIP protocol and CAN bus protocol is achieved through multi-protocol conversion; The application-layer web front-end provides unified dispatch and command, emergency broadcasting, scheduled broadcasting, device management, call record query, and emergency linkage with external systems.

2. The VoIP-based coal mine converged communication method according to claim 1, characterized in that: The process of initiating a voice or video call also includes: The call center sends an INVITE request to the called terminal through the FreeSWITCH softswitch server and automatically selects SIP, H.323 or WebRTC protocol to establish a session based on the type of the called terminal. After the called terminal returns 200 OK, the call center and the called terminal negotiate the audio and video codec selection and network connection parameters through Session Description Protocol (SDP). The audio and video media streams are transmitted via UDP using the real-time transmission protocol, and the session signaling is transmitted using TCP or WebSocket.

3. The VoIP-based coal mine converged communication method according to claim 1 or 2, characterized in that: In low-bandwidth scenarios underground, the voice encoding and decoding adopts G.711a / u encoding; In high-definition voice or video call scenarios, the voice codec uses OPUS encoding, and the video codec uses H.264 encoding or VP9 encoding. The audio and video media streams are encrypted and transmitted using the Secure Real-Time Transport Protocol (SRTP).

4. The VoIP-based coal mine converged communication method according to claim 1, characterized in that: The communication method also includes an emergency broadcast step: The dispatch console selects unicast mode, multicast mode, or mine-wide broadcast mode, and sends broadcast instructions to the selected broadcast terminals; After receiving the broadcast instruction, the broadcast terminal interrupts the current task to broadcast with the highest priority, and the converged communication server records the broadcast content and stores the broadcast record.

5. The VoIP-based coal mine converged communication method according to claim 1, characterized in that: The communication method further includes a timed broadcast step: Pre-set broadcast plans, including start time, end time, track list, and target broadcast terminal list; The converged communication server automatically performs timed broadcasts at the start time and performs volume enhancement processing after converting PDF or Word documents into standardized mp3 audio files.

6. The VoIP-based coal mine converged communication method according to claim 1, characterized in that: The communication method also includes an emergency response step: The converged communication server receives alarm commands from security monitoring systems, personnel positioning systems, or AI video recognition systems via a standard WebAPI interface. The converged communication server automatically triggers the broadcast terminal in the corresponding area to execute the highest priority alarm broadcast based on the alarm command.

7. The VoIP-based coal mine converged communication method according to claim 2, characterized in that: During the transmission of the audio and video media stream, when the packet loss rate reported by the Real-Time Transmission Control Protocol (RTCP) is greater than 5%, the FreeSWITCH softswitch server triggers a forward error correction mechanism or reduces the video bitrate. When the latency reported by the RTCP is greater than 300ms, the FreeSWITCH softswitch server enables jitter buffering or switches to a TURN (Traversal Using Relays around NAT) relay.

8. A VoIP-based coal mine converged communication system, characterized in that: This includes system infrastructure modules and converged communication software modules; The system infrastructure modules include an underground 10 Gigabit Ethernet ring network, a WIFI6 wireless network, a ground core switch, an underground core switch, a wireless base station, a broadcast terminal, explosion-proof mobile phones, SIP voice mining lamps, a voice gateway, PSTN fixed phones, and a converged communication server. The broadcast terminal is connected to the underground core switch via optical fiber. The explosion-proof mobile phones and SIP voice mining lamps are connected to the underground core switch via the wireless base station. The underground core switch is connected to the ground core switch via an optical fiber ring network. The voice gateway performs the conversion between SIP and PSTN protocols. The converged communication software module is deployed on the converged communication server and includes a hardware access layer, a data transmission layer, a core service support layer, and an application function layer. All terminal devices achieve unified registration management and status monitoring on the FreeSWITCH softswitch server through the standard SIP protocol. The core service support layer realizes audio and video converged communication between terminals with different protocols through the FreeSWITCH softswitch server, WebRTC technology, and the voice gateway.

9. The VoIP-based coal mine converged communication system according to claim 8, characterized in that: The core service support layer includes the FreeSWITCH softswitch server, the voice gateway, the multi-protocol conversion module, the status monitoring module, and the audio / video encoding / decoding module. The multi-protocol conversion module realizes real-time voice data conversion between SIP protocol and CAN bus protocol.

10. The VoIP-based coal mine converged communication system according to claim 8 or 9, characterized in that: The application function layer includes a communication scheduling module, an emergency broadcasting module, a timed broadcasting module, an equipment management module, a report query module, and a GIS single map module. The GIS single map module displays the location of underground terminal equipment and personnel on a geographic information system graphic and supports initiating audio and video calls directly from the geographic information system graphic to the terminal equipment.

11. The VoIP-based coal mine converged communication system according to claim 8, characterized in that: The hardware access layer supports TCP, UDP and CAN bus protocols to establish long-term connections with downhole hardware devices, and the data transmission layer uploads data to the converged communication server in real time through the downhole 10 Gigabit Ethernet ring network and the WIFI6 wireless network.

12. The VoIP-based coal mine converged communication system according to claim 8, characterized in that: The converged communication software module is developed based on the .NET 8.0 framework using the MVC pattern. The system software architecture of the converged communication software module is divided into the application function layer, service layer, data transmission layer and hardware access layer from top to bottom.

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