Standardization is the key to the development of the 2C market in telecom industry to the trillion level today. In the 2B market with diverse needs, the primary questions and challenges facing the standardization are what features 5G private network needs, who will lead the standardization work for 5G private network, and how to set the standards for vertical industries.
There are usually two ways to achieve standardization. One is for traditional telecom standards organizations such as 3GPP and China Communications Standardization Association (CCSA) to formulate standards and specifications according to the different needs of the industry, and the other is to build a public technology platform where industry needs can be converged, innovated and extended to help establish an ecosystem and develop solutions recognized by industry users. The integration of 5G and industries is a gradual process. 5G applications in vertical industries in China have developed from trial to wide-spread adoption. The standardization of 5G private network in China has embarked on an innovative route that combines the above two ways.
Breaking Industry Barriers
CCSA established the Industrial Internet Special Task Group (ST8) in 2017, responsible for the standardization work of the whole industry chain of industrial Internet. ST8 aims to build a good industrial ecosystem, improve the independent innovation ability of industrial big data, and make manufacturing management more convenient and efficient. Since 2020, CCSA has launched the industry standardization work item "5G+ Industrial Internet Application Scenario and Technical Requirements" for specific industries in ST8. At the end of 2019, CCSA also set up an ad hoc standard project team for 5G end-to-end network slicing to bridge the gaps in relative standards, specified the overall end-to-end architecture of 5G network slicing and capability requirements in related fields, and determined the standardization goal of promoting the application of 5G slicing in various vertical industries.
The Alliance of Industrial Internet (AII) reorganized the "Industrial Wireless Ad Hoc Group" into the "5G+ Industrial Internet Ad Hoc Group" in April 2021, dedicated to bridging the gap between 5G and industries, gathering experts from ICT enterprises, verticals and research institutes to explore 5G technologies and network solutions that meet the needs of industrial deployment and use, and to seek replicable and scalable application models as well as business models for sustainable growth. By January 2022, the number of members in AII had reached 2,160.
The 5G Application Industry Array (5G AIA) based on building an integrated innovative platform for 5G applications converges the superior resource of telecom enterprises, solves common industrial technology problems, and achieves coordination of the 5G application industry chain. It published the white paper on "5G Industry Virtual Private Network Architecture" in July 2020, focusing on the problems in implementing 5G networks
in vertical industries. According to the characteristics of different applications and scenarios in the industry, the white paper summarizes five key requirements such as cost reduction, diverse services, high security, self-operations, and system integration, which guide the standardization of 5G private WANs and LANs.
Coordination of Alliance and Industry Standards
AII and CCSA launched respectively the standardization of 5G private network in the industry sectors in 2020. The 5G private network standards they have specified cover industrial campus, power grid, mining industry, ports, high-end equipment manufacturing, aviation, cement and steel industry. The AII alliance standards are formulated quickly, and can serve as an important reference for the CCSA industry standards after the core parts are basically agreed. This mechanism leverages the advantage of AII to collect the professional advice of industry experts, ensure the recognition of 5G private network standards in the industry, achieve the coordination between the industry alliance and the communication standards organization, and shorten the time for CCSA to specify and release 5G private network industry standards. More industry standards will be launched under this mechanism in 2022, including the integration of 5G network with operational technology (OT), and 5G private network standards will be further promoted.
Guided by the "5G application 'sailing' action plan (2021-2023)", 5G private network has achieved good results in technical standards and industry promotion. At the end of 2021, a total of 12281 entries from 31 provinces, municipalities, autonomous regions and special administrative regions in China were received in the fourth "Blossom Cup" 5G application contest. Comparing with 4289 entries received in the third contest, the number of entries in 2021 increased explosively, of which the number of entries for industrial Internet ranked first. This shows that 5G has been deeply involved in industry growth.
Evolution Trend of International Standards for Private Network
To meet diverse needs of industrial digitization and factory automation, 3GPP started "Vertical_LAN", a 5G network architecture work item for vertical industry from Rel-16, and implemented the standardization work. The Vertical_LAN work item includes three distinct 5G enablers for verticals: time sensitive networking (TSN), non-public networks (NPN) and 5G LAN-type services. For these three features, 3GPP has enhanced the relevant standard solutions in Rel-17 and has decided to further study and develop work items based on the three features in the 5G-Advanced phase of Rel-18 (Fig. 1).
Time-Sensitive Network (TSN)
The IEEE TSN specifications will integrate deterministic and low-latency communication technologies in future factories. 5G time sensitive communication is a service that supports deterministic and synchronous communication with high reliability and availability. With enhanced evolution of Rel-16 TSN and Rel-17 industrial IoT (IIoT), the 5G system can integrate IEEE 802.1 TSN and provide time-sensitive communication as a bridge in TSN. Through network functions exposure and optimization of UE-UE time-sensitive communication, the 5G system supports enhanced deterministic applications.
The Rel-18 TSN features will be developed in the deterministic networking (DetNet) and 5G timing resiliency and TSC&URLLC enhancements (5TRS_URLLC) work items. Based on the work split between IETF DetNet WG and IEEE TSN, the DetNet work item studies how to enable deterministic QoS and time synchronization service by reusing the TSC framework defined in Rel-17 when placing the 5G system in the DetNet IP data plane network. The purpose of the 5TRS_URLLC work item is to study how to report the time synchronization status of the 5G system (such as the deviation of network timing sources of UTC and 5G systems) to UEs and third-party application functions (AFs), and how to enable AFs to request the time synchronization service in specific coverage areas and to request the highly reliable support and interworking with the TSN transport network.
Non-Public Network (NPN)
NPN provides a 5G network solution specifically used for industry users, including stand-alone non-public network (SNPN) and public network integrated NPN (PNI-NPN). In the Rel-17 eNPN work item, SNPN is enhanced to support more NPN application scenarios through cooperation between different networks or entities. For example, access authorization is provided for the UE without local certificate or subscriptions, and IMS as well as video, imaging and audio for professional applications (VIAPA ) scenarios are supported.
The Rel-18 eNPN_Ph2 work item further studies how to support mobility between SNPNs, how to access SNPN via non-3GPP, how to enable UE to discover, select, access the local hosting NPN and the localized services via the hosting NPN with proper authorization, and whether to enable NPN to support 5G proximity services.
5G LAN-Type Service
5G LAN-type service enables 5G network to provide services similar to LAN and VPN functions by improving 5G capabilities such as high performance, long-distance access, mobility, and security. The 5G LAN-type service can manage the group IDs, members, and group data of 5G virtual networks (VNs). The 5G VN group can be configured by the network administrator or dynamically managed by the third-party AF. In this way, the NEF is required to expose a set of services to manage the 5G VN group and 5G VN members. In addition, the 5G system supports routing optimization in the 5G LAN-type service scenario. When two UEs use the same user plane function (UPF), UE-UE communication can be achieved by directly enabling local data switching at the UPF without having to traverse the data network.
Rel-18 generic group management, exposure and communication enhancements (GMEC) is a work item for enhanced features of 5G LAN-type services. It intends to study how to enhance group attribute management and group status event reporting, enhance NEF exposure framework to enable capability exposure for provisioning of traffic characteristics and monitoring of performance characteristics applicable to each UE of a given group, enhance 5G VN group communication, and how to support group communication allowing UE to simultaneously send data to different groups, where each group has a different QoS policy, so as to meet the requirements of group communication scenarios in future factories.
Standardization is the commanding height of international economic, scientific and technological collaboration, and also the first move for enterprises, industries and equipment to "go abroad". China will accelerate the integration and improvement of 5G private network standards in 2022. ZTE remains committed to working with its industry partners, focusing on industry standardization organizations and alliances to make in-depth analysis on the characteristics of more industry requirements and find a balance between the versatility of 5G networks and meeting specific needs of various industries. In this way, standardization will become the "Quick Science Guide" and "Code for Improving Quality and Efficiency" for 5G to empower the industry, helping 5G promote the construction of global industrial Internet ecosystem.