3GPP 23.501 v20.2.0 — the document's own text
6.2.21 UE radio Capability Management Function (UCMF)
Taught in 4. What each network function does (The 5G system architecture, in depth), 10. Radio, Wi-Fi, cable — every way in (The 5G system architecture, in depth), 2. Who does what in the core (The 5G system architecture, overview).
The UCMF is used for storage of dictionary entries corresponding to either PLMN-assigned or Manufacturer-assigned UE Radio Capability IDs. An AMF may subscribe with the UCMF to obtain from the UCMF new values of UE Radio Capability ID that the UCMF assigns for the purpose of caching them locally.
Provisioning of Manufacturer-assigned UE Radio Capability ID entries in the UCMF is performed from an AF that interacts with the UCMF either directly or via the NEF (or via Network Management) using a procedure defined in TS 23.502 [3]. A UCMF that serves both EPS and 5GS shall require provisioning the UE Radio Capability ID with the TS 36.331 [51] format or TS 38.331 [28] format or both the formats of the UE radio capabilities.
The UCMF also assigns the PLMN-assigned UE Radio Capability ID values.
Each PLMN-assigned UE Radio Capability ID is also associated to the TAC of the UE model(s) that it is related to. When an AMF requests the UCMF to assign a UE Radio Capability ID for a set of UE radio capabilities, it indicates the TAC of the UE that the UE Radio Capability information is related to.
The UCMF stores a Version ID value for the PLMN assigned UE Radio Capability IDs so it is included in the PLMN assigned UE Radio Capability IDs it assigns. This shall be configured in the UCMF.
The UCMF may be provisioned with a dictionary of Manufacturer-assigned UE Radio Capability IDs which include a "Vendor ID" that applies to the Manufacturers of these UE and a list of TACs for which the PLMN has obtained-Manufacturer-assigned UE Radio Capability IDs.
A PLMN-assigned UE Radio Capability IDs is kept in the UCMF storage as long as it is associated with at least a TAC value. When a TAC value is related to a UE model that is earmarked for operation based on Manufacturer assigned UE Radio Capability IDs, this TAC value is disassociated in the UCMF from any PLMN assigned UE Radio Capability IDs.
For the case that the PLMN is configured to store PLMN assigned IDs in the Manufacturer Assigned operation requested list defined in clause 4.4.1a, the UCMF does not remove from storage any PLMN assigned UE Radio Capability ID no longer used and rather quarantines it to avoid any future reassignment.
A UCMF dictionary entry shall include also the related UE Radio Capability for Paging for each RAT.
NOTE: When more than one UCMF instances are deployed in the network, the uniqueness of the mapping of the UE Radio Capability ID to UE Radio Capability information is maintained based on implementation.