In the last chapter we saw Service Based Architecture.
In this chapter we shall see reference point architecture.
Image below shows the reference point architecture:
Here reference points are like we used to have in previous generations 4G, 3G.
The interactions between any two network functions will happen through reference points.
Eventhough the Network Functions have been interacting with Reference Points the functionality will remain the same.
There will be no changes in how the NF behaves in both the architecture.
In the above image, we can see the following reference points:
N1: Reference point between the UE and the AMF.
N2: Reference point between the (R)AN and the AMF.
N3: Reference point between the (R)AN and the UPF.
N4: Reference point between the SMF and the UPF.
N6: Reference point between the UPF and a Data Network.
N9: Reference point between two UPFs.
N5: Reference point between the PCF and an AF.
N7: Reference point between the SMF and the PCF.
N8: Reference point between the UDM and the AMF.
N10: Reference point between the UDM and the SMF.
N11: Reference point between the AMF and the SMF.
N12: Reference point between AMF and AUSF.
N13: Reference point between the UDM and Authentication Server function the AUSF.
N14: Reference point between two AMFs.
The reference points has been defined in TS 23.501
