Application of SPN Ethernet Ring Network in Smart Mine

Application Background and Requirements

The successive proposals of digital transformation strategies like Industry 4.0, Industrial Internet, and “Made in China 2025”, along with the rapid development of new-generation information technologies such as the Internet of Things, big data, cloud computing, and 5G, have propelled China’s mining industry towards intelligence. With China’s rich coal resources and limited oil and gas reserves, the coal industry plays a pivotal role in the country’s economic development. To promote integrated development of intelligent technologies and coal mining, eight departments including the National Development and Reform Commission, Energy Administration, and Coal Supervision Bureau jointly issued the “Guiding Opinions on Accelerating the Intelligent Development of Coal Mines” in March 2020. These opinions aim to ensure that by 2035, all types of coal mines will achieve intelligence, facilitating the creation of safe, efficient, and environmentally friendly coal mines supported by intelligent perception, decision-making, and automated execution.

Intelligence in coal mining is the cornerstone technology for enhancing the coal industry’s quality development. It is of great significance to boost the safety standards in coal mines and ensure a steady coal supply. Communication network infrastructure is integral to coal mine intelligence. Mines require diverse communication services, each with unique network requirements. Traditional mines generally deploy multiple physical fiber optic ring networks to meet the communication needs of various application systems.

In mines, dozens of application systems exist, spanning security, location, communication, video, and industrial control systems. The Energy Bureau has outlined basic requirements for application systems of coal enterprise informatization, each service system demanding specific quality assurances:

• The 5G system for mobile devices and personnel, above and under the mine, has comprehensive transmission requirements for large bandwidth, low latency, and extensive connectivity. Safety production monitoring networks must be independently constructed per policy mandates.
• Remote control of the comprehensive mining plane requires low latency and jitter.
• Various HD videos and VR/AR inspections require high bandwidth.
• Various underground sensor systems require extensive connectivity.

Each application system has multiple service connection points. The main station system may be located above the coal mine or within certain caverns inside it. Industrial control systems entail stringent safety requirements. The Energy Bureau clearly specifies that the network security of intelligent industrial control systems in fully mechanized mining operations should be at level two or above, with comprehensive consideration for data security in each application subsystem. Traditionally, meeing diverse service requirements involves separate system construction, leading to high costs and complex maintenance.

SPN Ethernet Ring Network Solution

To address the issues of high costs and complex maintenance brought about by the traditional siloed construction of mining communication networks, ZTE has proposed a solution: building a backbone transport network in mining areas to carry production services both above and under the mine. This involves constructing a physical ring network using metro transport network (MTN) hard slicing isolation technology, which provides multiple logical ring networks. These networks ensure service quality for various intelligent mining subsystems, offering low latency, low jitter, high reliability, high security, and good scalability in transmitting data across complex coal mine environments through ring networking (Fig. 1).

 A pair of slicing packet network (SPN) convergence devices are used for core convergence, with SPN access devices above the mine and SPN CPEs under the mine. A 100G ring network or a 50G ring network is used above and under the mine respectively to form a transmission self-healing protection ring, intersecting at active and standby centers with a bandwidth of at least 100 Gbps. The active and standby convergence nodes meet or exceed 2.0 level-3 information security standards, offering unified service interfaces for connection with data centers or office networks. Leveraging SPN’s low-delay feature, ring delay in the mining area is less than 1 ms, with multiple protection technologies like node protection, link protection, and active/standby redundancy, ensuring a highly reliable and intelligent mine backbone transmission system.

To meet data transmission and service requirements for each service subsystem, the 100G SPN Ethernet ring network is divided into five slices: network per site, industrial video, integrated monitoring, industrial control, and 5G transmission (Fig. 2). These slice subsystems employ virtual routing forwarding (VRF) to isolate services, ensuring hardware isolation for different service types and software isolation for identical service types. This approach guarantees reliable service transmission while facilitating classified service management and access for different service terminals. L2VPN over MPLS-TP tunnels or L3VPN over SR-TP tunnels can be selected based on service requirements and features to carry services. SPN convergence devices at both ends operate in hot or cold standby mode, with one end connected to a server for node protection. Within each slice, multiple PWs from the SPN access device at one end to the SPN convergence device at the same end can share the same tunnel, with tunnel protection configured. Network-side HQoS configuration is adjustable as required.

Refer to Table 1 for bandwidth configuration and slice allocation details for service systems. The industrial video slice is allocated 30 Gbps bandwidth, the 5G transmission slice has 20 Gbps, and the remaining three slices each have 10 Gbps. Additionally, 20 Gbps bandwidth is reserved, allowing for flexible allocation and adjustment of slice bandwidth as needed.

This solution leverages 5G transport technology, especially hard slicing isolation, to significantly reduce network construction costs and simplify O&M, laying a solid foundation for intelligent mining development. It offers the following benefits:

• Super-large bandwidth: The all-optical backbone ring network can smoothly expand to 100GE bandwidth, meeting service development needs for the next decade.
• One integrated network: Utilizes one fiber, one set of equipment, and one integrated network for industrial, video, and 5G multi-network integration.
• Security isolation: The FlexE technology supports end-to-end hard service isolation, meeting differentiated service quality requirements.
• Independence: China’s new-generation international 5G transport standard has completed extensive commercial verification.

Practical Implementation

ZTE cooperated with Changzhou Institute of China Coal to build an industry-leading 100G SPN Ethernet slice ring network for Shaanxi Coal and Chemical Industry Group’s Xizhuo coal mine in November 2022. This network provides integrated service transmission for both aboveground and underground production in smart mines. ZTE SPN devices use the MTN hard slicing isolation technology to provide a physical ring network for mining operations, with multiple logical rings catering to various intelligent mine subsystem services.

The successful application of SPN technology in the B2B field will lay a reliable foundation for the development of intelligent mines at the Xizhuo coal mine, accelerating the digital transformation towards 5G+ intelligent mining.