5gc interfaces

The 5G system is designed with a service-oriented architecture and consists of various functional entities that communicate with each other through standardized interfaces. These interfaces play a crucial role in ensuring interoperability and seamless communication within the 5G network. Here are some of the key 5G Core (5GC) interfaces, explained in technical detail:

1. N1 Interface (UE - NG-RAN):
   • Purpose: The N1 interface connects the User Equipment (UE) to the Next-Generation Radio Access Network (NG-RAN).
   • Protocol Stack: It uses the PDCP (Packet Data Convergence Protocol) and RLC (Radio Link Control) protocols for user plane data transmission.
2. N2 Interface (NG-RAN - AMF):
   • Purpose: The N2 interface connects the NG-RAN to the Access and Mobility Management Function (AMF) in the 5GC.
   • Protocol Stack: It uses the NGAP (Next-Generation Radio Access Network - Application Part) protocol for control plane signaling.
3. N3 Interface (NG-RAN - UPF):
   • Purpose: The N3 interface connects the NG-RAN to the User Plane Function (UPF) in the 5GC.
   • Protocol Stack: It uses the NGAP protocol for control plane signaling and the NG-U (Next-Generation User Plane) protocol for user plane data transmission.
4. N4 Interface (AMF - SMF):
   • Purpose: The N4 interface connects the AMF to the Session Management Function (SMF) in the 5GC.
   • Protocol Stack: It uses the N4 Application Protocol (N4-AP) for control plane signaling.
5. N6 Interface (SMF - UPF):
   • Purpose: The N6 interface connects the SMF to the UPF in the 5GC.
   • Protocol Stack: It uses the N4-AP protocol for control plane signaling and the NG-U protocol for user plane data transmission.
6. N7 Interface (SMF - PCF):
   • Purpose: The N7 interface connects the SMF to the Policy Control Function (PCF) in the 5GC.
   • Protocol Stack: It uses the N4-AP protocol for control plane signaling.
7. N8 Interface (PCF - UDM):
   • Purpose: The N8 interface connects the PCF to the Unified Data Management (UDM) in the 5GC.
   • Protocol Stack: It uses the N4-AP protocol for control plane signaling.
8. N9 Interface (UDM - AUSF):
   • Purpose: The N9 interface connects the UDM to the Authentication Server Function (AUSF) in the 5GC.
   • Protocol Stack: It uses the N4-AP protocol for control plane signaling.
9. N10 Interface (AUSF - SEAF):
   • Purpose: The N10 interface connects the AUSF to the Security Edge Protection Function (SEAF) in the 5GC.
   • Protocol Stack: It uses the N4-AP protocol for control plane signaling.
10. N11 Interface (SEAF - NEF):
    • Purpose: The N11 interface connects the SEAF to the Network Exposure Function (NEF) in the 5GC.
    • Protocol Stack: It uses the N4-AP protocol for control plane signaling.

These interfaces define the interactions between various network functions in the 5G system, enabling the delivery of high-performance services and functionalities. The protocols used for control plane signaling and user plane data transmission are standardized to ensure compatibility and interoperability among different vendors' equipment.