Glossary

Protocols

NGAP: NG Application Protocol used over N2 interface
S1AP: S1 Application Protocol used over S1-AP interface
Diameter: S6a, Gx interface
NAS: Non-Access-Stratum used between UE & MME/AMF.
PFCP: Packet Forwarding Control Protocol
GTPU: GTP user plane protocol. Used on s1-U, s5-U, N3, N9 interfaces
GTPv2: GTP control plane protocol used on s11 interface between MME & SGW

Network Functions

AMF: Access and Mobility Management Function
UPF: User Plane Function
SMF: Session Management Function
NRF: Network Repository Function
NSSF: Network Slice Selection Function
PCF: Policy & Charging Function
AUSF: Authentication Server Function
UDM: Unified Data Management
UDR: Unified Data Repository
CHF: Charging Function
NWDAF: Network Data Analytics Function
NEF: Network Exposure Function
MME: Mobility Management Entity
SGW: Serving Gateway
PGW: PDN Gateway
HSS: Home Subscriber Server
PCRF: Policy and Charging Rule Function

3gpp Interfaces

N2: gNodeB to AMF interface
N4: SMF to UPF interface
SBI interface
S1AP: eNodeB to MME interface

Misc

SA: Standalone Architecture URLLC : Ultra Reliable Low Latency Communication