GB/Z 41296-2022General technical requirements of information system for production safety, spot monitor and emergency rescue of colliery (English PDF)

Foreword

This document was drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.

This document is under the jurisdiction of the National Technical Committee on Communication of Standardization Administration of China (SAC/TC 485).

The drafting organizations of this document are Datang Telecom Technology and Industry Group, China Academy of Information and Communications Technology, Xi'an University of Posts and Telecommunications and Beijing University of Posts and Telecommunications.

The main drafters of this document are Xu Hui, Du Jiadong, Wang Anyi and Hu Bo.

1 Scope

This document specifies the application architecture, interface definitions and business processes of the information system for production safety, monitoring and emergency rescue of coal mines, the requirements for the sensing extension layer and the network layer, and the requirements for business support and security.

This document applies to information systems of the coal industry.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

YD/T 1806-2008, Technical requirements for IP-based remote video monitoring equipment.

3 Terms and definitions

No terms and definitions are listed in this document.

4 Abbreviations

The following abbreviations apply to this document.

ADSL: Asymmetric Digital Subscriber Line; ERP: Enterprise Resource Planning; FTTx: Fiber To The x; GIS: Geographic Information System; IP: Internet Protocol; MOS: Mean Opinion Score; OMC: Operation and Maintenance Center; SMS: Short Message Service; RFID: Radio Frequency Identification; WEB: World Wide Web; WLAN: Wireless Local Area Network; xDSL: generic term for the various (x) Digital Subscriber Line technologies; 2G: 2nd generation mobile communication system; 3G: 3rd generation mobile communication system; 4G: 4th generation mobile communication system.

5 Application definition

5.1 Overview. Coal mining is an underground operation and production is a complex whole made up of many processes and links: geological exploration, surveying, development, tunnelling, transport and hoisting, drainage, ventilation, power supply, blasting, roof support, coal cutting and coal preparation. Besides the accident factors common to other industrial enterprises, coal mines face their own natural hazards such as water, fire, gas, coal dust and roof; roof falls, gas explosions, coal and gas outbursts, spontaneous combustion, coal dust explosions and flooding, as well as electromechanical and transport accidents, seriously affect safe and efficient underground production. Fundamentally improving coal mine safety is therefore a prerequisite for the sustained, stable and healthy development of the coal industry, and coal industry information systems are an important technical guarantee for strengthening production safety, preventing accidents and modernizing safety management.

The information system for coal mine production safety, monitoring and emergency rescue comprises the safety monitoring and control system, the production dispatching and command system, the mine integrated automation system, the emergency rescue command system and the communication system.

5.2 Safety monitoring and control system. To ensure mine safety, changes in the mine are monitored, displayed and alarmed locally, and transmitted over the network to the surface for storage and analysis; together with expert systems, the system forecasts or helps prevent mine disasters and, when a disaster occurs, provides correct rescue measures to prevent it from spreading. The system collects in real time information such as advance footage, output, micro-seismicity, hydrology, gas, dust, ground pressure, fire areas, video, personnel position and equipment status, and displays information for normal production and disaster periods on computer screens through visual charts and audible and visual alarms, providing a basis for decision makers and decision systems. For example, through the gas monitoring system the gas concentration at any gas sensor of each mine and its variation can be viewed in the surface monitoring room or on any computer connected to the Internet, gas emission trends can be studied from historical data, and in abnormal situations the system raises audible and visual alarms and notifies the persons concerned by mobile phone short message. Informatization of safety monitoring requires networked and intelligent safety sensors and an open network platform that delivers safety information to the relevant management departments.

5.3 Production dispatching and command system. The system networks safety and production dispatching and command, forming an integrated dispatching system combining real-time processing of safety and production information, dispatching decision support, production command and office automation. Dispatchers and mine managers can know at any time the operating status of every production link of the whole mine and handle situations promptly. It requires an integrated information query system providing safety information, multimedia applications such as video conferencing and network video telephony, multi-party voice calls, real-time interaction with industrial surveillance video, and multi-level network security and network management.

5.4 Mine integrated automation system. The system builds the surface and underground parts of the mine into one unified automation network platform, used for automation and unmanned operation of coal cutting and tunnelling, transport and hoisting, ventilation and dust control, compressed air and grouting, power distribution, drainage and gas drainage; automation reduces labour intensity, raises efficiency and, through unmanned operation, achieves intrinsic safety. For example, a transport and hoisting automation system coordinates all links, avoids mismatch and blockage at transfer points and bunkers, and takes disaster control measures automatically, such as braking when a belt tears or starting fire extinguishing devices when a belt catches fire. Centralized control of surface and underground electromechanical equipment and real-time personnel monitoring are performed from the surface control and command centre.

The surface monitoring subsystems include fans, air compressors, main and auxiliary shaft hoists, plant substations, water treatment and boiler heating networks, surface combined pump houses and water treatment, domestic sewage and rainwater treatment, tube bundle systems, coal preparation plants and 35 kV or 110 kV substations; the underground subsystems mainly include belt conveyor monitoring, central substation, central pump house, district substation and pump house monitoring, coal face and heading face monitoring, underground safety monitoring, personnel positioning and underground cooling systems. All of them transmit information over the network to the surface production dispatching and command centre.

5.5 Emergency rescue command system. Because of the complexity of coal mining, accidents such as gas explosions, roof falls and water inrushes can occur; the emergency rescue command system provides important help for timely and effective rescue. It generally consists of an on-site environment monitoring system for the disaster area, a rescue decision expert system and a video surveillance system. The video surveillance system dynamically monitors the disaster site and displays and stores images in real time; the environment monitoring system samples automatically and continuously and analyses toxic and harmful gases at the monitoring points, providing a scientific basis for rescue commanders; the expert system analyses the mine situation, defines hazard ranges and makes a preliminary forecast of disaster development. The emergency rescue command system should provide two-way voice communication, image transmission, and collection and recording of underground environmental parameters.

5.6 Communication system. It consists of the surface communication system of the mining area and the underground communication system of the coal mine. The surface system consists of the telephone network, transmission network, access network, dispatching communication network and support systems, and is the means by which mine management collects information on production and business activities and exercises command. The underground system carries communication between the links of coal mine production and the transfer of dispatching, monitoring and control information from the dispatching room to each production link, ensuring safe production; it consists of the mine dispatching communication system, mine wired communication system, mine wireless mobile communication system and underground disaster relief communication system.

5.7 Needs of the information system for coal mine production safety, monitoring and emergency rescue. 5.7.1 Multi-service, remote integrated monitoring. The coal industry needs multiple services, including data, video, voice and dispatching, meeting production safety and management function requirements throughout production and operation management. Remote integrated monitoring should support cross-regional management by coal mining groups, with data integration and wide-area transmission for each mine.

5.7.2 Three-layer, four-level networked management. Existing coal industry networks are not sufficient for multi-service remote integrated monitoring; public and private networks need to be combined to build a four-level (national - provincial - enterprise group - mining area) network safety application system providing remote hierarchical monitoring, management and expert diagnosis, with three business management layers: network data layer, expert support layer and decision layer. Each mining area centre sends all data from its surface and underground application systems over the network to the enterprise-group safety centre; the group centre incorporates the statistical data of each mining area through a data synchronization mechanism, uses the data of the group's application systems as auxiliary information, summarizes and analyses system operation and data anomalies, and serves experts and the provincial centre; the provincial safety centre calls the data of each enterprise group, summarizes and analyses system operation and data anomalies monthly, conducts year-end assessment of group management and forms a provincial data centre for expert systems and decision making; the national safety centre sees the data chain of every coal mine in every province, summarizes and analyses anomalies, and concentrates all expert support data as the basis for decisions.

The three layers run through the whole four-level network and form three systems that coordinate and reinforce each other: the network data layer is the data source of the monitoring and diagnosis centres and serves experts and engineers at enterprise and provincial level; the expert support layer analyses existing alarms and provides solutions, enabling remote support; the decision layer shares and uses this information on the common data platform.

Figure 1 shows the three-layer four-level management flow as a sequence diagram between the mining area, enterprise group, provincial and national safety centres: (1) each mining area centre sends all data over the network to the group safety centre; (2) the group centre incorporates mining area statistics through data synchronization and uploads summaries and statistics of system operation and data anomalies to the provincial centre; (3) the provincial centre calls group data and uploads monthly summaries and statistics to the national centre; (4) the group centre analyses the data and sends solutions to the mining area centre; (5) the provincial centre sends solutions to the group and mining area centres; (6) the national centre sends solutions to the provincial, group and mining area centres; (7) the mining area centre forwards all collected analyses and solutions level by level; (8) the group centre returns the final solution to the mining area centre; (9) the provincial centre returns the final solution to the group and mining area centres; (10) the national centre returns the final solution to the provincial, group and mining area centres.

5.7.3 Localized production dispatching of coal mines and wide-area early-warning dispatching. 5.7.3.1 Localized production dispatching: the system issues production orders from higher levels, assigns and implements production tasks and passes production information between levels; dispatching orders must reach grassroots production units quickly, which work according to plan, and task progress, production situations and emergencies are fed back rapidly so that managers can decide and act in time. 5.7.3.2 Wide-area early-warning dispatching: when an accident or disaster occurs in a mine, wide-area dispatching can mobilize not only the mine's own resources but also remote dispatching and expert management through the government and the coal mine safety administration.

5.8 Service definitions. 5.8.1 Voice services. 5.8.1.1 Overview. By application environment, voice services in coal enterprises are divided into surface and underground voice services. Surface voice services include fixed telephone voice, mobile network voice, Internet-based voice services, calling-card voice, short messages and walkie-talkie communication, carried over surface networks and mainly required to be real-time, intelligible and clear. Underground voice is an important service for production safety: through underground voice terminals, surface dispatching and monitoring staff communicate promptly with underground workers, and underground workers report site conditions to the surface by voice. It is mainly implemented by the dispatching telephone communication system. Chinese coal mining is mainly underground, with roadways up to tens of kilometres long, many processes, dispersed working places and highly mobile personnel, which places high demands on dispatching communication; the centre of the dispatching system is the surface dispatching room, while the focus of work is underground.

The authority of the dispatcher shall be ensured, with non-blocking calls between the dispatcher and dispatched stations and guaranteed call priority and reliability. Mine production requires: a local underground dispatching subsystem allowing non-blocking calls between internal units and inter-system call paths through the dispatching console; call paths between internal users and external parties (via trunk lines); call priorities so that emergency calls are handled first; broadcast calls to all underground users or multi-party conferences; the highest call priority for the dispatching console; and call management rights for the console, including forced break-in and forced release of trunk or user calls when necessary. 5.8.1.2 Traditional voice services mainly include non-dispatching voice calls on fixed or mobile telephones, dispatching calls initiated by the dispatching switchboard or console, and multi-party voice calls.

5.8.1.3 Voice dispatching services. 5.8.1.3.1 Non-blocking call: when the dispatcher calls a dispatching terminal, the call is connected whether the terminal is busy or idle; a terminal calling the dispatcher is given priority and shown on the console. 5.8.1.3.2 Forced break-in: the dispatcher can break into any call of a dispatched user at any time, hold a three-party call or mask one party for a two-party call, the masked party being held and reconnected when the dispatcher leaves. 5.8.1.3.3 Forced release: the dispatcher can force termination of any call involving a dispatched user; parties may be kept or released, released resources are freed and kept parties continue a two-party call with the dispatcher. 5.8.1.3.4 Dispatching group call: frequently used users are pre-arranged in groups and all users of a group are called simultaneously with a group key. 5.8.1.3.5 Multi-state user status display: indicator lights of different colours show whether a user is unregistered, idle, ringing or in a call. 5.8.1.3.6 Dispatch recording: all calls through the dispatching host can be recorded, manually or automatically. 5.8.1.3.7 Multiple consoles: the dispatching centre supports several consoles, with calls distributed among them on a random allocation principle.

5.8.1.3.8 Queuing: automatic call distribution (ACD) balancing traffic among positions; queuing in order of arrival; allocation to the position idle longest; different priorities by calling user or called service code, with higher priority calls placed at the front; voice and music prompts while queuing; automatic answer; and overflow transfer. 5.8.1.3.9 Emergency call: between the console and dispatched users; a user's emergency call gives a visible and audible signal distinct from normal calls and recording starts automatically or manually; a console emergency call rings the user's phone distinctly and ringing stops automatically when the user answers, or, if the user does not answer, the handset loudspeaker is opened within a set time so that the dispatcher can speak; wireless terminals have an emergency button that calls the dispatching centre without dialling. 5.8.1.3.10 Any-call pickup: the dispatcher can pick up any extension calling the console and, after a call, answer or call other users without hanging up. 5.8.1.3.11 Call transfer between users. 5.8.1.3.12 Caller display of number and name in Chinese on the console. 5.8.1.3.13 Call hold switching: while in a call, the dispatcher can take a new incoming call while the first party hears a waiting message, then switch back.

5.8.1.3.14 Multi-party call: the console can group-call two or more groups simultaneously, each group calling 20 users at the same time, and can connect external lines into the call. 5.8.1.3.15 Dispatch monitoring: during a call between dispatched users, the dispatcher can listen in by pressing the monitoring key and the key of either user, and exits by hanging up. 5.8.1.3.16 Remote dispatching: authorized persons can initiate dispatching of a specific group of terminals from anywhere through an intelligent dispatching terminal, either via a console or by a terminal command executed automatically by the dispatching centre, in which case dispatch recording is switched on automatically.

5.8.2 Message services. 5.8.2.1 SMS: point-to-point and point-to-multipoint short messages. 5.8.2.2 Point-to-point and point-to-multipoint instant messaging shall provide: immediate delivery; retry later or discard, according to filtering criteria, when the recipient temporarily cannot receive; delivery result (success or failure) to the sender; showing or hiding the sender's identity; multiple media types such as text, images, audio and video; message filtering rules by sender address, size, content type and format; and group sending. 5.8.2.3 Session-based messaging: sender and receivers join the same message group and the sender reaches all members without their individual addresses, as in a chat room.

5.8.3 Data services. 5.8.3.1 Overview. Data services carry monitoring, control and command data of the safety monitoring and control system, the production dispatching and command system, the mine integrated automation system and the emergency rescue command system. They provide query, display, retrieval, statistics and multi-service linkage for analogue parameters such as underground gas, air velocity, carbon monoxide, temperature and negative pressure, and for switching parameters such as start and stop of electromechanical equipment, opening and closing of air doors and power supply status. Data from underground safety monitoring and automation systems are normalized through a unified data interface standard and integrated into a multi-level networked coal mine production safety information platform for remote hierarchical monitoring, management and expert diagnosis; integration with GIS associates production information with geographic location for personnel positioning, attendance and service queries.

5.8.3.2 Coal mine safety monitoring services. 5.8.3.2.1 Terminals monitor the analogue and switching parameters listed above. 5.8.3.2.2 Real-time data display: according to assigned permissions, safety management users view monitoring data on terminals in real time. 5.8.3.2.3 Data query by combinations of mine number, sensor number, sensor type, substation number, status and query start and end time. 5.8.3.2.4 Real-time statistics of abnormal sensor data: automatic display and refresh of mine name, sensor faults, number of suspended sensors, sensors not inspected, substation faults, over-range values, calibrations, power cuts, alarms and update time. 5.8.3.2.5 Multi-service linkage: when a major hazard source reaches its pre-critical value and this is transmitted to the remote monitoring system, a series of linked data, voice, video, positioning and SMS actions is triggered automatically. 5.8.3.2.6 Association of monitoring data with dispatching: production data are classified in the dispatching centre's data management system and each class is associated with one or more groups of dispatched persons; when the console enters a data type the related persons are listed automatically; these associations are stored in the dispatching data centre.

5.8.3.2.7 Download of associated data: when an intelligent terminal retrieves production data, the list of related persons is downloaded with their names and main information. 5.8.3.2.8 Nested dispatching within retrieval: while retrieving data, an intelligent terminal can dispatch related persons by remote dispatching; recording is switched on automatically and the dispatcher may join selectively.

5.8.3.3 Production control services. Data of underground safety monitoring and automation systems (main and auxiliary hoisting, centralized belt control, power supply, ventilation, underground drainage, coal flow metering, etc.) are normalized through a unified data interface standard and integrated into the multi-level networked production safety information platform of the national safety administration - provincial safety administration - enterprise group safety bureau - mining area safety department, with GIS integration for positioning, attendance and queries. Main functional requirements: unified data format integrating data of all automation control systems; a multi-level networked information sharing platform supporting intelligent analysis such as expert online diagnosis and gas prediction; rich software interfaces seamlessly integrating subsystems for integrated control of the whole mine; data query and statistics, historical curves, report printing, level-by-level alarms, hierarchical data management, alarm and fault logging and complete event logging; powerful graphic configuration with split-screen display of real-time dynamic graphics of each subsystem; industrial Ethernet ring at the control layer and fieldbus at the device layer to ensure real-time performance. 5.8.3.4 Business management services: office automation, enterprise ERP and expert online support systems.

5.8.4 Video services. 5.8.4.1 Overview. Surface staff monitor by video the equipment and places relevant to safety, such as winch rooms, fan rooms, warehouses, shaft mouths and roadways, where temperature and humidity, gas concentration, current and voltage need continuous dynamic monitoring; this allows real-time underground monitoring and dispatching, recording of site safety, early detection of accident precursors and first-hand images for accident analysis. The enterprise-group safety centre can view each subordinate mine command centre and shaft, switch pictures, remotely control camera pan-tilt units and combine multiple video pictures; each mine command centre does the same within its area. The group safety centre can hold video conferences (shift handover, production and summary meetings) with multi-point two-way audio and video interaction; the chairman can set regular meetings with fixed members, members can join and leave at any time, and the chairman controls the right to speak and can broadcast any venue.

5.8.4.2 Video monitoring functions. Through video acquisition equipment the surface dispatching and command centre monitors underground areas in real time, such as main haulage roadways, travelling roadways and main working faces, with manual, scheduled, motion-triggered and alarm-linked recording, automatic deletion when storage is full, lens and pan-tilt control, and video compression, network transmission and sharing. Requirements: video browsing and multi-picture display; pan-tilt (lens) control through the business support platform, such as focus, pan-tilt, image parameters and display adjustment, zooming and moving remote images; instant recording stored locally or on the business support platform; scheduled recording with search and playback; monitoring on various display terminals such as industrial television, computers and mobile phones; image compression chosen according to the access network of the monitoring equipment; monitoring software in WEB and client/server modes. 5.8.4.3 Video dispatching: the dispatcher monitors site images through visual terminals, and video terminals can be linked with voice equipment for synchronized voice and video calls.

5.9 Service performance requirements. 5.9.1 IP voice services shall meet: voice quality MOS >= 3.5 when network packet loss is < 5 %, and MOS >= 3 when packet loss is between 5 % and 10 %; call setup time < 5 s; call loss < 0.1 %; block error rate <= 1 %. 5.9.2 Data services shall support standard network transmission protocols with a transmission bit error rate below 10^-8. 5.9.3 Video services shall comply with the performance requirements of YD/T 1806-2008.

6 Application framework

6.1 Architecture. The application architecture of the coal information system is shown in Figure 2 and consists of four parts: the sensing extension system, the network transmission system (private network), the coal industry information application management system and the coal industry supervision and management system. The application management system and the supervision and management system can be connected through the public network transmission system, and independent terminals of the sensing extension system can also access the public network. Figure 2 shows the application management system (authentication and key servers, business application system with communication dispatching, personnel management, automation control, video monitoring, safety monitoring and other applications, operation and maintenance system and business support system), the private network (WLAN, Ethernet, ADSL, 2G/3G/4G), the public network (Internet, 2G/3G/4G), the supervision system (monitoring and other supervision applications) and the sensing extension system (gateway equipment with sensing, video monitoring and RFID devices, and independent wireless, fixed, control, broadcast and execution terminals and sensors).

The sensing extension system consists of independent terminals, sensing extension layer devices (such as sensing devices) and device gateways, and performs data acquisition, dispatching and control execution. The private network provides cellular wireless access (2G, 3G, 4G), wired access (Ethernet, ADSL) and short-range wireless access (WLAN) for long-distance transmission of coal industry data. The application management system consists of the business application system (communication dispatching, personnel management, automation control, etc.), the business support system (unified data processing) and the operation and maintenance system (operation and maintenance of the other two), and reports production and business data to the supervision system over the public network. The supervision and management system is used by government departments for remote supervision of production and operation of coal enterprises and obtains data through the public network, which uses wired (Ethernet, ADSL) or wireless (WLAN, 2G, 3G, 4G) access for long-distance transmission of public information.

6.2 Functional description of each part. 6.2.1 Sensing extension system. 6.2.1.1 Overview: sensing extension devices collect environment, equipment and personnel information and execute alarm and control information; the device gateway converts signalling and data formats and sends the information over the network to the application management system; independent terminals perform voice communication, production dispatching and control execution.

6.2.1.2 Sensing devices collect data at monitoring points and may display locally, alarm on limit exceedance and execute commands from the gateway or application management system; they correspond to sensors such as smoke, temperature, methane and equipment status sensors, connect to the gateway by wire or wirelessly, and network in star, tree or self-organizing topologies, some having strong networking and data forwarding capability. 6.2.1.3 Video monitoring devices monitor important production links on the surface and underground and send information via the gateway or directly over the network. 6.2.1.4 RFID devices collect attribute information of personnel and equipment and send it via the gateway or directly. 6.2.1.5 Independent terminals connect to the network without a gateway: wireless and fixed communication terminals, control terminals, broadcast terminals and execution terminals. 6.2.1.6 Gateway equipment connects sensing extension layer devices and the network, providing configuration and networking, protocol conversion, address mapping, data forwarding and security control; whether it is installed depends on application needs.

6.2.2 Network transmission system (private network) and public network transmission system. They carry data between sensing extension devices and the application management and supervision systems. The private network carries data between sensing devices (sensing, video monitoring, RFID), gateways and independent terminals and the application management system; the public network carries data between independent terminals and terminals outside the coal information system, and allows the supervision system to access the application management system. Access may be wired or wireless, such as WLAN, 2G, 3G, 4G, Ethernet and ADSL.

6.2.3 Coal industry information application management system. 6.2.3.1 It consists of the business application system, the business support system and the operation and maintenance system, and controls and manages all coal information applications. 6.2.3.2 The business application system provides production, management and decision staff with services such as personnel management and automation control, managing and controlling specific services. 6.2.3.3 The business support system provides a unified data access interface to business applications, stores and distributes data from all transmission modes, and provides the interface through which the supervision system accesses the coal information system. 6.2.3.4 The operation and maintenance system manages and configures the business support and business application systems. 6.2.4 The coal industry supervision and management system supervises the conduct and operation of coal enterprises, for example tax supervision and emergency event handling supervision.

6.3 Interface definitions. 6.3.1 Sensor device to device gateway: several formats are supported, such as Ethernet IEEE 802.3i, ZigBee, RFID, CAN and RS485, but application layer data shall use a unified communication protocol. 6.3.2 Video monitoring device to device gateway: shall meet YD/T 1806-2008. 6.3.3 RFID to device gateway: several physical interface formats, such as Ethernet IEEE 802.3i, but application layer data transmission shall use a unified communication protocol.

6.4 Business processes. 6.4.1 Data services (Figure 3, sequence between safety and production monitoring subsystems, business support system and terminal): 1) the intelligent or local terminal registers with the remote monitoring centre; 2) the mine monitoring subsystems (development, tunnelling, coal cutting, transport, drainage, hoisting, coal preparation, outbound transport, power supply, ventilation, personnel positioning, etc.) send real-time monitoring data to the business support system; 3) the terminal sends service requests such as production data or monitoring data calls; 4) the business support system authenticates the identity and permissions of the terminal to prevent information theft by illegal users and assigns permissions for production information; 5) if authentication succeeds, service information is returned; 6) if it fails, service is refused.

6.4.2 Production command and dispatching voice services (Figure 4, sequence between terminal, application management system and dispatching console): 1) the console provides normal or emergency production dispatching and voice services to terminal users and area managers; 2) the intelligent or local terminal registers with the application management system; 3) the application management system and the console synchronize user identity and call information; 4) the terminal sends a service request; 5) the application management system performs identity and permission authentication, for requests such as forced release in multimedia dispatching; 6) if authentication succeeds, the console issues the service request message and the voice service proceeds. 6.4.3 Video services (Figure 5, sequence between video monitoring system, business support system and terminal): 1) the terminal registers with the business support system; 2) the business support system and video monitoring system synchronize terminal identity and service information; 3) the terminal requests a video service; 4) the business support system authenticates and authorizes the terminal; 5) after successful authentication and authorization, video service starts between the terminal and the video server.

7 Requirements for the sensing extension layer

7.1 Overview. The sensing extension layer comprises the sensing extension network and the sensing extension gateway. The network consists of sensing extension devices such as terminals, sensors and controllers, including wireless communication terminals, broadcast terminals, power supply monitoring, ventilation monitoring and environment monitoring devices, networked on protocols such as Zigbee, RFID, CAN and RS485. The gateway supports multiple communication protocols and data types between devices, converts data communication formats, unifies uplink data formats, and maps downlink acquisition and control commands into messages conforming to the specific device protocol.

7.2 Capability requirements. 7.2.1 Device classification. 7.2.1.1 Data devices include: power supply monitoring devices (feed, current, voltage and power sensors); ventilation monitoring devices (air velocity, air pressure, duct switch and air door switch sensors); environment monitoring devices (methane, carbon monoxide, carbon dioxide, oxygen, smoke and temperature sensors); control devices (methane power-off instruments, wind-power-methane interlock devices, power-off controllers, audible and visual alarms, actuators including alarms and circuit breakers, equipment start-stop sensors); coal cutting, tunnelling and development monitoring devices (rock bolt pressure, borehole stress, roof pressure and coal level sensors); transport system monitoring devices (belt deviation, coal pile-up, belt slip and vibration/displacement sensors); drainage monitoring devices (liquid level and flow sensors); personnel position monitoring devices (identification cards and position monitoring substations); weighing devices (truck scales, belt scales and rail scales). 7.2.1.2 Voice devices: voice communication devices (mobile phones, walkie-talkies, fixed telephones) and voice broadcasting devices (loudspeakers, broadcast speakers). 7.2.1.3 Video devices: cameras.

7.2.2 Technical requirements of devices: reference may be made to relevant national standards and coal industry technical specifications; Annex A lists some of them. 7.2.3 Access capability. 7.2.3.1 Network access capability covers access types, access modes, device identification and addressing: device types include those listed in 6.2.1; access to the gateway may differ by device, including RFID, Zigbee, RS485, CAN, RJ45, switching signal lines, analogue signal lines, video lines, audio lines and optical cables; because device types and protocols vary, standardized device coding (gateway type, gateway code, device category, device code) shall be used for addressing and access. 7.2.3.2 Gateway access capability: gateway types are data, voice or video; the gateway shall support data coordination and aggregation within the sensing network; depending on the service, it shall access the network layer via RS485, CAN, Ethernet or wireless communication. 7.3 Networking capability: the sensing network can be built on protocols such as Zigbee, RFID, CAN and RS485, and accesses the network layer through the sensing extension gateway.

8 Requirements for the network layer

8.1 General technical requirements. 8.1.1 Integration: since many data types are transmitted, the network shall support integrated services including voice, video and data of various magnitudes, with corresponding quality of service (QoS) guarantees. 8.1.2 Reliability: of data acquisition, data fusion and data transmission; observed data are the basis for applications and judgement, and reliable acquisition, fusion and transmission are the basis of normal system operation. 8.1.3 Diversity: since data types, acquisition forms and transmission methods may differ, standardized connection definitions between data acquisition, transmission and processing modules shall be considered so that the network can support many types of applications quickly and conveniently. 8.1.4 Controllability: terminal and transmission equipment meeting given standards shall be brought under terminal management with standardized registration, identification and authentication methods, and network management interfaces for access management, service management and device management shall be provided to keep the network controllable.

8.2 Capability requirements of the network layer: star, tree, ring, bus and hybrid networking; network congestion handling; multi-terminal handling; remote device management; signalling congestion handling. 8.3 Access capability requirements: the network layer should reliably transmit sensing data to the communication peer through one or more long-distance access modes such as 2G and 3G mobile communication, xDSL, FTTx, broadband wireless access and satellite/microwave; support multi-service flow connections between network and terminals; support QoS mechanisms for different transmission rates, delay requirements, transmission intervals and packet sizes; and support security mechanisms for user plane and management plane data transmission of gateways and terminals.

9 Requirements for business support

9.1 Capability requirements. Business support shall support: voice communication and multimedia dispatching management; coal mine equipment monitoring systems; video monitoring for industrial television systems; coal mine personnel attendance and positioning systems; coal enterprise information management systems; geological survey and ventilation management systems; and rescue or auxiliary rescue capability of emergency rescue systems.

9.2 Interface requirements. Unified interface functions shall be provided between the business application layer and the network transmission layer, mainly unified interface data formats, unified interface function definitions and unified interface technical requirements. 9.3 Network management requirements. Network management shall support configuration management, performance management, alarm management and security management of network layer devices, remote operation and maintenance of network layer devices, and configuration, establishment and maintenance of OMC operation and maintenance channels.

10 Security requirements

10.1 Equipment security requirements: equipment shall meet coal industry equipment safety specifications.

10.2 Data security requirements: the coal industry information system may provide encryption and integrity protection of data.

10.3 Application security requirements: the coal industry information system may provide access control, authorization and authentication for user access.

Annex A (informative) Selected technical specifications to be followed by sensing extension equipment terminals

A.1 Extract of basic standards. Basic standards for sensing extension layer terminals include the explosive atmospheres series: GB/T 3836.1-2021 (Part 1: Equipment - General requirements), GB/T 3836.2-2021 (Part 2: Equipment protection by flameproof enclosures "d"), GB/T 3836.3-2021 (Part 3: Equipment protection by increased safety "e"), GB/T 3836.4-2021 (Part 4: Equipment protection by intrinsic safety "i"), GB/T 3836.5-2021 (Part 5: Equipment protection by pressurized enclosure "p"), GB/T 3836.6-2017 (Part 6: Equipment protection by liquid immersion "o"), GB/T 3836.7-2017 (Part 7: Equipment protection by powder filling "q"), GB/T 3836.8-2021 (Part 8: Equipment protection by type of protection "n"), GB/T 3836.9-2021 (Part 9: Equipment protection by encapsulation "m"), GB/T 3836.12-2021 (Part 12: Material characteristics for combustible dusts - Test methods), GB/T 3836.13-2013 (Part 13: Equipment repair, overhaul, reclamation and modification), GB/T 3836.14-2014 (Part 14: Classification of areas - Explosive gas atmospheres) and GB/T 3836.15-2017 (Part 15: Electrical installations design, selection and erection).

A.2 Extract of technical standards for mine sensors: AQ/T 6203-2006 (low-concentration catalytic methane sensors for coal mines); AQ/T 6205-2006 (electrochemical carbon monoxide sensors for coal mines); GB/T 15478-2015 (performance test methods for pressure transducers); GB/T 7551-2008 (load cells); MT/T 381-2007 (general technical conditions of temperature sensors for coal mines); MT/T 382-2011 (general technical conditions of smoke sensors for mines); MT 393-1995 (differential pressure sensors for mines); MT 443-1995 (sensors for underground environment monitoring in coal mines); MT 445-1995 (high-concentration thermal conductivity methane sensors for coal mines); MT 447-1995 (electrochemical oxygen sensors for coal mines); MT 448-2008 (air velocity sensors for mines); MT/T 530-1995 (underground emergency lockout switches for coal mines); MT/T 531-1995 (speed sensors for coal mines); MT/T 647-1997 (equipment start-stop sensors for coal mines); MT/T 648-1997 (belt deviation sensors for coal mines); MT/T 825-1999 (water level sensors for mines); MT/T 844-1999 (air door open-closed state sensors for mines).

A.3 Extract of technical standards for controllers: MT 631-1996 (wind-power-methane interlock devices for coal mines); AQ 6208-2007 (fixed methane power-off instruments for coal mines); MT 282-1994 (portable methane power-off instruments for coal mines).

A.4 Extract of technical standards for communication equipment: GB/T 15279-2002 (technical conditions of automatic telephone sets); GB/T 15844-2017 (general specification for professional mobile FM transceivers); GB/T 18220-2012 (information technology - general specification for handheld information processing devices); GB/T 18287-2013 (general specification of lithium-ion cells and batteries for mobile phones); MT 287-1992 (signalling equipment for coal mines); MT 289-1992 (intrinsically safe common-battery and automatic telephone sets for coal mines); MT 290-1992 (main performance test methods for those telephone sets); MT 401-1995 (production dispatching communication systems for coal mines); MT 402-1995 (safety couplers for dispatching telephones); MT 403-1995 (manual dispatching telephone switchboards); MT 404-1995 (through-type dispatching telephone switchboards); MT 405-1995 (automatic dispatching telephone switchboards); MT 406-1995 (underground communication junction devices); MT/T 992-2006 (through-the-earth wireless communication equipment for underground space); MT/T 1006-2006 (signal converters for mines); MT/T 1007-2006 (information transmission interfaces for mines).

A.5 Extract of technical standards for explosion-proof photographic cameras (instruments): GB/T 13953-1992 (explosion-proof performance test methods for flameproof television equipment) and GB/T 15411-1994 (general technical conditions of explosion-proof television).

Bibliography

[1]-[13] GB/T 3836.1-2021, GB/T 3836.2-2021, GB/T 3836.3-2021, GB/T 3836.4-2021, GB/T 3836.5-2021, GB/T 3836.6-2017, GB/T 3836.7-2017, GB/T 3836.8-2021, GB/T 3836.9-2021, GB/T 3836.12-2021, GB/T 3836.13-2013, GB/T 3836.14-2014, GB/T 3836.15-2017, Explosive atmospheres (Parts 1 to 9, 12, 13, 14 and 15). [14] GB/T 7551-2008, Load cells. [15] GB/T 13953-1992, Explosion-proof performance test methods for flameproof television equipment. [16] GB/T 15279-2002, Technical conditions of automatic telephone sets. [17] GB/T 15411-1994, General technical conditions of explosion-proof television. [18] GB/T 15478-2015, Performance test methods for pressure transducers. [19] GB/T 15844-2017, General specification for professional mobile FM transceivers. [20] GB/T 18220-2012, Information technology - General specification for handheld information processing devices. [21] GB/T 18287-2013, General specification of lithium-ion cells and batteries for mobile phones.

[22] AQ/T 6203-2006, Low-concentration catalytic methane sensors for coal mines. [23] AQ/T 6205-2006, Electrochemical carbon monoxide sensors for coal mines. [24] AQ 6208-2007, Fixed methane power-off instruments for coal mines. [25] MT 282-1994, Portable methane power-off instruments for coal mines. [26] MT 287-1992, Signalling equipment for coal mines. [27] MT 289-1992, Intrinsically safe common-battery and automatic telephone sets for coal mines. [28] MT 290-1992, Main performance test methods for intrinsically safe common-battery and automatic telephone sets for coal mines. [29] MT/T 381-2007, Temperature sensors for coal mines. [30] MT/T 382-2011, Smoke sensors for mines. [31] MT 393-1995, Differential pressure sensors for mines. [32] MT 401-1995, Production dispatching communication systems for coal mines. [33] MT 402-1995, Safety couplers for production dispatching telephones in coal mines. [34] MT 403-1995, Manual production dispatching telephone switchboards for coal mines. [35] MT 404-1995, Through-type production dispatching telephone switchboards for coal mines. [36] MT 405-1995, Automatic production dispatching telephone switchboards for coal mines. [37] MT 406-1995, Underground communication junction devices for coal mines.

[38] MT 443-1995, Sensors for underground environment monitoring in coal mines. [39] MT 445-1995, High-concentration thermal conductivity methane sensors for coal mines. [40] MT 447-1995, Electrochemical oxygen sensors for coal mines. [41] MT 448-2008, Air velocity sensors for mines. [42] MT/T 530-1995, Underground emergency lockout switches for coal mines. [43] MT/T 531-1995, Speed sensors for coal mines. [44] MT 631-1996, Wind-power-methane interlock devices for coal mines. [45] MT/T 647-1997, Equipment start-stop sensors for coal mines. [46] MT/T 648-1997, Belt deviation sensors for coal mines. [47] MT/T 825-1999, Water level sensors for mines. [48] MT/T 844-1999, Air door open-closed state sensors for mines. [49] MT/T 992-2006, Through-the-earth wireless communication equipment for underground space. [50] MT/T 1006-2006, Signal converters for mines. [51] MT/T 1007-2006, Information transmission interfaces for mines.