5.41 NR RedCap UEs differentiation
23.5013GPPRelease 18System architecture for the 5G System (5GS)TS
This functionality is used by the network to identify traffic to/from UEs accessing over NR RedCap, e.g. for charging differentiation.
An NR RedCap UE using NR shall provide an NR RedCap indication to the NG-RAN during RRC Connection Establishment procedure as defined in TS 38.300 [27].
When the UE has provided an NR RedCap indication to the NG-RAN during RRC Connection Establishment, the NG-RAN shall provide an NR RedCap Indication to the AMF in the Initial UE Message (see clause 4.2.2.2.1 of TS 23.502 [3] and TS 38.413 [34]).
When the AMF receives an NR RedCap Indication from NG-RAN in an Initial UE Message, the AMF shall store the NR RedCap Indication in the UE context, consider that the RAT type is NR RedCap and signal it accordingly to the SMSF during registration procedure for SMS over NAS, to the SMF during PDU Session Establishment or PDU Session Modification procedure. The PCF will also receive the NR RedCap RAT type indication when applicable, from the SMF during SM Policy Association Establishment or SM Policy Association Modification procedure.
During handover from E-UTRA to NR, the target NG-RAN (i.e. gNB) provides the NR RedCap indication to AMF in NGAP Path Switch Request message during Xn handover, or NGAP Handover Request Acknowledge message during N2 handover (including intra 5GS N2 handover and EPS to 5GS handover) based on the UE capability information provided by the source RAN to the target RAN as specified in TS 38.300 [27].
The NFs interacting with CHF shall include the NR RedCap as RAT type.
Upon AMF change, the source AMF shall provide the "NR RedCap Indication" to the target AMF.