Section: 5.15.13 Support of data rate limitation per Network Slice for a UE
Content: A UE subscription information may include an optional Slice Maximum Bit Rate for the UE (Subscribed UE-Slice-MBR) for an S-NSSAI, which applies for 3GPP access type only. The Subscribed UE-Slice-MBR includes a UL and a DL value. If a Subscribed UE-Slice-MBR is associated to an S-NSSAI in the subscription information, it is provided by the AMF to the NG-RAN when the AMF provides the Allowed NSSAI for the UE to the NG-RAN as UE-Slice-MBR QoS parameter. The UE-Slice-MBR QoS parameter is defined in clause 5.7.2.6. If the Subscribed UE-Slice-MBR for a UE changes, the AMF updates UE-Slice-MBR in the NG-RAN accordingly. In roaming case, the UE-Slice-MBR is provided for the S-NSSAI of the VPLMN which maps to the S-NSSAI of the HPLMN and the AMF may first interact with the PCF for authorization of the Subscribed UE-Slice-MBR. If the AMF interacts with the PCF, the PCF may provide the Authorized UE-Slice-MBR that is used as UE-Slice-MBR by the AMF as described in clause 6.1.2.1 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [45]. For a roaming UE, the S-NSSAI of the VPLMN maps to only one S-NSSAI of the HPLMN for which an UE-Slice-MBR is applied. The enforcement of the UE-Slice-MBR value, if present in the UE context in the NG-RAN for an S-NSSAI, is described in clause 5.7.1.10. NOTE: The PCF for the PDU Session may in addition be configured to monitor the data rate per Network Slice for a UE and to strengthen or relax the traffic restrictions for individual PDU Sessions or PCC rules accordingly, as described in TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [45] clause 6.2.1.9.