Service Request (5G) (5G Service Request Procedure)

The 5G Service Request procedure (3GPP TS 23.502 §4.2.3) is initiated by the UE in CM-IDLE — or by the network via paging — to establish user-plane resources for one or more PDU Sessions and re-activate the N2/N3 tunnels on the AMF and UPF. It is the main state transition between CM-IDLE and CM-CONNECTED and a key measurement point for signaling load.

Categories: Core Network

Service Request (5G) in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

To place Service Request (5G) in the wider telecom-security picture, review 5G, 5G SA, 5G NSA, 5G SBA, ACL and AES — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.