5.7.2.4.3 Usage of Notification control with Alternative QoS Profiles during QoS Flow establishment and modification

During QoS Flow establishment and modification, a prioritized list of Alternative QoS Profile(s) can be provided to the NG-RAN for the QoS Flow in addition to the QoS profile. If the NG-RAN is not able to guarantee the GFBR, the PDB and the PER included in the QoS profile and if Alternative QoS Profiles are provided to the NG-RAN and the NG-RAN supports Alternative QoS Profiles, the NG-RAN shall check whether the GFBR, the PDB and the PER values that it can fulfil match at least one of the Alternative QoS Profile(s) taking the priority order into account. If there is a match between one of the Alternative QoS Profiles and the GFBR, the PDB and the PER values that the NG-RAN can fulfil, the NG-RAN shall accept the QoS Flow and indicate the reference to that Alternative QoS Profile to the SMF. If there is no match to any Alternative QoS Profile, the NG-RAN shall reject the QoS Flow establishment or modification.

After a successful QoS Flow establishment or modification during which the NG-RAN indicated that the currently fulfilled QoS matches one of the Alternative QoS Profiles, the NG-RAN shall treat this QoS Flow in the same way as if it had sent a notification that the "GFBR can no longer be guaranteed" with a reference to that Alternative QoS Profile to the SMF (as described in clause 5.7.2.4.1b).

If the SMF has received a reference to an Alternative QoS Profile during QoS Flow establishment and modification the SMF may inform the PCF about it (as described in TS 23.503 [45]).

If the PCF has not indicated differently, the SMF shall use NAS signalling (that is sent transparently through the RAN) to inform the UE about the QoS parameters (i.e. 5QI, GFBR, MFBR) corresponding to the referenced Alternative QoS Profile.