What is Control Plane?
The control plane carries all signalling information used to establish, maintain, and manage communication sessions and network resources. It is entirely separate from the user plane (which carries actual data traffic). In 5G, strict control/user plane separation (CUPS) is a core architectural principle.
How Does Control Plane Work?
In 5G, control plane functions are handled by: AMF (registration and mobility), SMF (session management), PCF (policy), AUSF (authentication), NSSF (slice selection), and NRF (service discovery). The UE communicates with the AMF via NAS (Non-Access Stratum) protocol over the N1 reference point. The gNB communicates with the AMF via NGAP over N2.
Use Cases
Device registration, handover preparation and execution, QoS policy enforcement, network slice selection, emergency call priority, lawful intercept signalling.
3GPP / Standards Reference
3GPP TS 23.501 (5G System Architecture), TS 38.413 (NGAP Protocol)
Related Terms
AMF | SMF | CUPS | Data plane | SBA
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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.
