Section: 4.27 Procedures for Enhanced Coverage Restriction Control via NEF 4.27.1 General
Content: The support for Enhanced Coverage Restriction Control via NEF enables AF to query status of Enhanced Coverage Restriction or enable/disable Enhanced Coverage Restriction per individual UEs. Figure 4.27.1-1 shows the procedure for Enhanced Coverage Restriction Control via NEF. Figure 4.27.1-1: Enhanced Coverage Restriction Control via NEF 1. The AF may enable or disable Enhanced Coverage Restriction or query the status of Enhanced Coverage Restriction by sending the Nnef_ECRestriction_Update Request or Nnef_ECRestriction_Get Request respectively. Both the service operations require GPSI and AF Identifier as required input and optionally MTC Provider Information. 2. Based on operator policies, if the AF is not authorized to perform the request (e.g. if the SLA does not allow for it) or if the AF has exceeded its quota or rate of submitting Enhanced Coverage Requests, the NEF performs Step 8 and provides a cause value appropriately indicating the failure result. 3. The NEF sends the Nudm_ParameterProvision_Update Request to update the subscription data for Enhanced Coverage Restriction. The NEF sends the Nudm_SDM_Get Request service operation to query the status of Enhanced Coverage Restriction. 4. The UDM checks the GPSI and examines whether any included parameters are in the range acceptable by the operator, whether Enhanced Coverage Restriction is supported by the serving NF (i.e. AMF in this case). If this check fails, the UDM provides a cause value indicating the reason for failure condition to the NEF in step 7 In the case of Nudm_ParameterProvision_Update Request, the UDM sets the Enhanced Coverage Restriction information to the appropriate value and procedure continues to step 5. In the case of Nudm_SDM_Get Request, the UDM may retrieve the status of Enhanced Coverage Restriction information from UDR using Nudr_DM_Query Request and skip steps 5 and 6. 5. The UDM sends Nudm_SDM_Notification and provide AMF with updates Enhanced Coverage Restriction information. 6. The AMF updates the Enhanced Coverage Restriction information stored in the UE context. The AMF will transfer Enhanced Coverage Restriction information stored as part of its UE context during AMF change. NOTE: UE is informed of the updated Enhanced Coverage Restriction information at the next Registration procedure or based on the local policy the network can de-register the UE indicating re-registration is required. 7. The UDM sends the Nudm_ParameterProvision_Update Response or Nudm_SDM_Get Response to the NEF. 8. The NEF sends the Nnef_ECRestriction_Update Response or Nnef_ECRestriction_Get Response to the AF.