What is Core Network?
The core network is the central part of a mobile network providing subscriber management, routing, authentication, policy control, and connectivity to external networks (internet, IMS for voice). In 5G, it is called the 5G Core (5GC), built as a cloud-native, microservices-based architecture using the Service-Based Architecture (SBA).
How Does Core Network Work?
The 5GC replaces the 4G EPC’s network elements (MME, SGW, PGW, HSS, PCRF) with modular Network Functions (AMF, SMF, UPF, PCF, UDM, AUSF, NRF, NSSF, NEF) that communicate via HTTP/2 RESTful APIs. This enables deployment on commercial cloud infrastructure (Kubernetes/OpenStack), independent scaling of functions, and rapid feature deployment.
Use Cases
Subscriber authentication and authorisation, IP address allocation, QoS policy enforcement, interconnection to internet and IMS, roaming support, network slicing orchestration.
3GPP / Standards Reference
3GPP TS 23.501 (5GC Architecture), TS 23.502 (Procedures), TS 29.500 (SBA HTTP/2 transport)
Related Terms
AMF | SMF | UPF | SBA | Network Slicing | EPC
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This glossary entry is part of the 5GWorldPro Complete 5G Glossary. To go deeper into 5G architecture and technology, explore our 5G Training courses.
