Page 88 - ITU-T Focus Group IMT-2020 Deliverables

3 ITU-T Focus Group IMT-2020 Deliverables

NOTE 1 – The above messages can be sent independently or by piggybacking on other relevant messages,
e.g. While sending "PDU session establishment" message to NF2, NF1 can piggyback "Add UE binding"
message for creating binding between the UE's session and NF1's serving instance, at the IRF.
6.1.1.2.2.2 Solution 2.2: NFs discovery solution

(Source: Huawei, HiSilicon, China Mobile)
One general model for the interconnection of CP NFs is depicted as the following figure:

Figure 6.1.1-7 – The general model of the interconnection of CP NFs
The high level principles are utilized in the general model of the interconnection of CP NFs
– The NF (Function Consumer) determines the function type of the NF (Function Provider) that it
needs to access;
– The NF (Function Consumer) shall be able to obtain the instance of the NF (Function Provider) after
performing NF discovery;
– The NFs (Function Consumer) shall be able to obtain the function of the NF (Function Provider) via
the same interface provided by the NF (Function Provider);
– The general communication protocol is used to transfer the message between the NF (Function
Consumer) and the NF (Function Provider);
– The NF (Function Provider) authorizes the functionality that one NF (Function Consumer) can access
per UE granularity;

– The interface which one NF provides its functionality to other NFs is not changed per the
interconnected NFs.

The NF discovery procedure in one PLMN is depicted in the following figure:

Figure 6.1.1-8 – NF discovery procedure in one PLMN

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