Research on SPN 2.0 Technical Features and Application Solutions in Industry Scenarios

The 14th Five-Year Plan marks a pivotal phase in China’s digital and intelligent transformation. The 5G+ industrial Internet will drive innovation to develop new applications and ecosystems. Key sectors like power, transportation and railways will undergo gradual upgrades via private networks. The Ministry of Industry and Information Technology’s Industry Internet Innovation and Development Action Plan (2021–2023) outlines strategies supporting the advancement of “5G+ industrial Internet” and deploying new technologies such as deterministic networks. To develop high-quality 5G+ industrial Internet and private networks, the focus includes upgrading enterprise intranets, integrating IT with OT networks, building secure campus networks, establishing external networks for enterprises with high-performance, high-reliability, high-flexibility and high-security network services, deploying new technologies such as cloud-network/computing-network convergence, deterministic networks, and IPv6 segment routing (SRv6), and promoting industrial access to high-quality external networks with a focus on data and network security.

In collaboration with the China Academy of Information and Communications Technology (CAICT) and leading device manufacturers, China Mobile actively drives technological innovation and industrial applications in the slicing packet network (SPN) field for various industrial scenarios. The practical implementation of application solutions is underway in sectors like power, transportation, coal mines, ports, healthcare, and industrial campuses. In January 2023, the Research Report on the Requirements and Application of SPN in Industrial Scenarios was approved during the plenary session of the Industrial Internet Industry Alliance.

Transport Demand Analysis in Typical Industry Scenarios

Network transport demands differ across various industry scenarios. For instance, in typical service scenarios like 5G+ industrial Internet and smart grids, Table 1 outlines variations in transport capabilities and index requirements for communication networks across eight service scenarios (5G+ UHD video, 5G+ remote control, 5G+ cloud-based AGV, 5G+ machine vision, 5G+ drone, 5G+ cloud robot, 5G+ AR, and 5G+ VR) and smart grids.

To meet differentiated service requirements across different industries, the transport network needs to possess the following features:

• Hard isolation slicing: In the industrial sector, diverse scenarios including production control, collection/detection, and information monitoring, require end-to-end hard isolation slicing for effective management of mixed and complex traffic flows.
• Carrier-class reliability: Production services in the industrial Internet and smart grids require 99.999% or higher network reliability. This necessitates end-to-end high-reliability network protection and recovery mechanisms, and carrier-class O&M.
• Deterministic transport: For deterministic needs in scenarios like industrial control and monitoring, research is crucial for constructing end-to-end deterministic networks and innovating deterministic transport technology across wide-area heterogeneous networks.
• Flexible access and scheduling: In the industrial sector, service terminals and types vary widely, featuring diverse network interfaces, protocols, and communication demands. A key aspect of a transport network is to ensure extensive access, collaborative operation, and flexible, efficient scheduling and forwarding of heterogeneous terminals.
• Versatile service perception: In-depth service perception and the application of new ICT technologies strongly support the digital transformation and high-quality development of industrial users. Achieving deep integration with these technologies presents a major challenge for communication networks.
• Intelligent control and O&M: Intelligent, convenient and open network O&M greatly improves the operational efficiency and autonomy of various industrial Internet services. It reduces response time for new service deployment, enabling agile innovation in the industry.

Standardization and Technical Features of SPN 2.0

SPN 2.0 surpasses SPN 1.0 in multiservice transport, cloud-network convergence, network coverage, intelligent control and O&M, and low-carbon energy efficiency. With new frame structures and cross-connect technologies supporting N×10 Mbps fine granularity units (FGU), it expands 10GE small access SPN devices for private line access and industrial campus application. Moreover, it enhances the integrated transport of 5G+ vertical industries, enterprise private lines, and cloud-network/computing-network convergence services.

Starting in mid-2019, China Mobile explored SPN fine-granularity technology for 5G+ industries and enterprise private lines. It adopted the N×10 Mbps-based FGU solution, releasing the Technical White Paper on SPN FGU in June 2021. By the second half of 2021, enterprise standards were completed. In June 2022, SPN 2.0 technical white paper and private line products were launched, and comprehensive evaluation of multi-vendor SPN 2.0 equipment is ongoing. China’s Ministry of Industry and Information Technology (MIIT) has officially published three SPN industry standards: YD/T 3826-2021, YD/T 3974-2021, and YD/T 4172-2022. Additionally, three industry standards, including Test Methods for SPN Equipment, have been submitted for approval. Research is ongoing for six industry standards, such as Technical Requirements for Fine-Granularity Transport of SPN and Technical Requirements for Interworking of SPN.

As a key technology in the SPN slicing channel layer, metro transport network (MTN) has systematic international standards in ITU-T. By January 2023, five international standard recommendations (MTN architecture G.8310, MTN interface G.8312, MTN equipment function G.8321, MTN linear protection G.8331, MTN network management and control G.8350) and one technical report of network evolution G.sup.69 had been released. The MTN synchronization standard was completed in 2023. At the September 2022 ITU-T SG15 plenary session, Chinese members successfully obtained approval for the G.fgMTN standard, indicating international recognition for the core architecture and key technologies of the MTN extension fine-granularity sub-channel.

Research on SPN 2.0 Application Solutions in Industrial Scenarios

• Analysis of SPN 2.0 Applications in Industry Scenarios

The industrial Internet includes two network application scenarios: industrial intranet and industrial external network. The industrial intranet connects the data of production, control and other enterprise sectors, managing daily operations through OT and IT networks. The industrial external network provides highly reliable, low-latency connections for remote production control. Telecom operators in China must evolve into integrated service providers supporting the industrial Internet. Their networks should not only prioritize reliable security, carrier-class high reliability and deterministic transport, but also ensure ubiquitous access, flexible networking, visual and intelligent control, and SLA guarantee.

SPN 2.0 primarily serves industrial external networks in industrial Internet applications. It can also be applied to specific industrial intranet scenarios, like coal, ports, and industrial campuses, as required. The small access SPN 2.0 device functions as the egress gateway for industrial intranets, facilitating effective connections to industrial external networks. This includes integrated transport with multi-service security isolation, end-to-end network slice interworking and scheduling, and service capability exposure for different industry slices.

SPN 2.0 features soft, hard, and hierarchical network slicing using N5 Gbps and M10 Mbps MTN channels. It provides deterministic transport similar to SDH VC-4/VC-12 TDM hard isolation and soft isolation with N5 Gbps MTN interfaces. This enables high-security isolation, highly reliable unified transport, and differentiated SLA guarantees for various industrial Internet services such as production control, information management and Internet access (Fig. 1). It ensures comprehensive competitiveness in current transport network technology with independent and controllable key technologies and a promising long-term development prospect.

• SPN 2.0 Applications in 5G+ Smart Grids and Private Power Networks

The 5G-based virtual private network in the power industry offers ultra-low latency, massive connections, and ultra-high bandwidth. It enables end-to-end hard and soft slicing, ensuring various levels of security isolation for services across different power grid areas. This facilitates applications like 5G+MEC+slice for remote control, differential protection, DTU, distributed energy, and intelligent preventive maintenance, addressing communication challenges at the smart grid’s endpoints.

5G power distribution network services, categorized into control and collection, vary in security levels. This includes differential protection with low delay/jitter and high reliability, power distribution automation requiring high synchronization precision, and large-bandwidth video conferencing. SPN power industry wireless slices use PRB reservation. Transport SPN is deployed through 5 Gbps coarse-grained or 10 Mbps fine-grained MTN slices, and UPF takes the form of ToB UPF. The main electric power station and ToB UPF employ VPN enterprise customer slices and 100 Mbps VPN private lines, ensuring assured bandwidth delivery (Table 2).

China Southern Power Grid has planned to deploy a new SPN-based power communication network since 2021 for transporting voice/video LAN, integrated data network, and 2M private line services. The solution supports large-bandwidth networking, hard slicing isolation, intelligent O&M, and 10 Mbps FGU, as illustrated in Fig. 2.

Application Prospects

SPN, a new-generation transport network technology jointly developed by Chinese operators, research institutions, and network device vendors, is a leading model in China for transport network standard innovation. Recognized by ITU-T, SPN has achieved a large-scale deployment of over 340,000 nodes on China Mobile’s 5G transport network, marking substantial industrial progress.

SPN 2.0, with innovative TDM and packet statistics multiplexing, offers deterministic low latency, multi-granularity cross-connection, hierarchical slicing, and flexible intelligent perception. It is widely applied in typical industrial scenarios such as smart grid, smart transportation, smart mine, smart port, smart healthcare and smart manufacturing, and is emerging as a benchmark for the new-generation integrated service transport network.