5G Core Network

In Release 15, the 5G Core (5GC) introduced foundational support for interworking and migration from the EPC, including a dual registration mode and specific procedures for E-UTRA cells connected to both cores. Key new capabilities included PGW selection for 5GC UEs on untrusted non-3GPP access, security mechanisms for non-Service Based Architecture interfaces, and enhanced support for emergency calls over non-3GPP access and during core network mobility. The release also formalized network behaviors like overload control, roaming barring, and corrections to security keys for ng-eNodeBs connected to the 5GC.

• OI#19 - 5GC-EPC interworking: PGW selection for 5GC UE for connectivity via untrusted access TS 23.402CR2980
• Security mechanisms for non-SBA interfaces in 5GC TS 33.501CR0374
• Selection of NAS procedures for E-UTRA connected to both EPC and 5GC TS 23.501CR0147
• TS 23.501 mobility from EPC to 5GC TS 23.501CR0024
• EPC to 5GC Migration fixes for Option 7 TS 23.501CR0084
• Dual Registration mode of operation from E-UTRA cell connecting to both EPC and 5GC TS 23.501CR0283

+ 26 more changes

In Release 16, the 5G Core was enhanced to support a wider range of devices and access technologies, including the formal introduction of NB-IoT, eMTC, and wireline access via 5G-RG/FN-RG connections to the 5GC. It also introduced new core capabilities such as Suspend-Resume procedures, DNN replacement functionality, and support for Integrated Access and Backhaul (IAB) architecture. Furthermore, Release 16 expanded 5GC deployment scenarios with improvements for non-3GPP access, charging interworking with EPC, and support for Non-Public Networks (SNPN).

• Restriction of use of Enhanced Coverage in 5GC TS 23.501CR0820
• Access to 5GC from UEs not supporting NAS over non-3GPP access TS 23.501CR1128
• Handling of IAB-indication to 5GC TS 23.501CR1901
• AMF Location Service Operations for a Commercial and Deferred 5GC-MT-LR TS 29.518CR0262
• Solution for IAB Architecture - 5GC TS 33.501CR0782
• Introduction of NBIOT dedicated CP functions when connected to 5GC TS 38.410CR0018

+ 21 more changes

In Release 17, the 5G Core network introduced enhancements for Multi-Access PDU sessions, allowing simultaneous connectivity over E-UTRAN/EPC and non-3GPP access. It also added support for dynamically changing policies within the 5GC, improved support for RedCap UE differentiation, and extended UPIP support for all NG-RAN architecture options. Furthermore, the release included features like 5GC-assisted cell selection for network slices, 5GC-assisted EAS discovery authorization, and enhanced capabilities for handover to the N3IWF.

• MA PDU sessions with connectivity over E-UTRAN/EPC and non-3GPP access to 5GC TS 23.501CR2527
• 5G system architecture updates to support Dynamically Changing Policies in the 5GC TS 23.501CR2560
• Support of 5GC assisted cell selection to access network slice TS 23.501CR2719
• 5GS Connection release support for 5GC/NR TS 23.501CR3088
• Support RedCap UEs differentiation in 5GC TS 23.501CR3155
• UE authorization for 5GC assisted EAS discovery TS 29.503CR0755

+ 9 more changes

In Release 18, key 5GC enhancements included the introduction of spending limits for Access Management and UE policies, support for the 5GC-MT-LR procedure involving a Mobile Base Station Relay, and enabling UE-level measurements collection. It also added specific support for authentication via an AAA Server for NSWO, defined the User Location Information format for a 5G-RG acting as a TNAP, and extended capabilities for WLAN and W-5GAN access scenarios, including MPS and service restrictions. Furthermore, the release refined support for federated learning via the NWDAF and addressed various corrections for procedures like PIN handling and handovers from EPS.

• Discovery and Selection of the NWDAF Supporting Federated Learning in 5GC TS 23.501CR3772
• MPS when access to 5GC is WLAN TS 23.501CR3745
• PIN support in 5GC TS 23.501CR3854
• 23.501 - Spending Limits for AM and UE Policies in the 5GC TS 23.501CR3886
• 23.501 - Spending Limits for AM and UE Policies in the 5GC TS 23.501CR4666
• Support of 5GC-MT-LR procedure involving Mobile Base Station Relay TS 29.515CR0120

+ 16 more changes

In Release 19, key enhancements for the 5G Core focused on improving network resilience and introducing new charging and monitoring capabilities. Specifically, it introduced new procedures for the detection and PCF-based restoration of EPC/5GC Network Function failures, including health checks and recovery for IMS services. Furthermore, the release added support for CHF discovery based on a CHF GroupId, extended charging support, and enabled the configuration and transfer of QoS monitoring capability within the 5GC.

• Add a new clause of detection of EPC/5GC NF failures and IMS restoration procedures TS 23.380CR0127
• Add the PCRF/PCF-based restoration solution for EPC/5GC NF failure TS 23.380CR0128
• EPC/5GC health check and recovery upon IMS Terminating Call TS 23.380CR0134
• CHF discovery support based on CHF GroupId in 5GC TS 29.503CR1409
• Extending Charging support in 5GC TS 29.507CR0335
• 5GC Network Functions health check and failure recovery TS 29.513CR0617

+ 6 more changes

In Release 20, the 3GPP specifications introduced enhancements to the management framework for the 5G Core (5GC) and NG-RAN. This was achieved by adding missing foundational concepts and background information to the relevant management specification. These additions provide a more complete and structured foundation for managing these key network functions.

• Rel-20 CR TS 28.540 add missing concepts and backgrouds of management of NG-RAN and 5GC TS 28.540CR0055