The feature is activated in the gNB either by direct configuration from the OAM system (management-based activation), or by signalling from the OAM via the 5GC (signalling-based activation), containing UE-associated QoE configuration. One or more QoE measurement collection jobs can be activated at a UE per service type, and each QoE measurement configuration is uniquely identified by a QoE reference. When the UE is configured with MR-DC, only the MN can configure the QoE configuration.
For signalling-based QoE measurements, the OAM initiates the QoE measurement activation for a specific UE via the 5GC, and the gNB receives one or more QoE measurement configurations by means of UE-associated signalling. The QoE measurement configuration for signalling-based activation includes an application layer measurement configuration list and the corresponding information for QoE measurement collection, e.g., QoE reference, service type, MCE IP address, slice scope, area scope, MDT alignment information and the indication of available RAN visible QoE metrics.
For management-based QoE measurement activation, the OAM sends one or more QoE measurement configurations directly to the gNB. The QoE measurement configuration for management-based activation also includes an application layer measurement configuration list and the corresponding information for QoE measurement collection. The gNB selects UE(s) that meet the required QoE measurement capability, area scope and slice scope.
Application layer measurement configuration received by the gNB from OAM or CN is encapsulated in a transparent container, which is forwarded to a UE as Application layer configuration in the RRCReconfiguration message (there can be multiple configurations in the same message). Application layer measurement reports received from UE's application layer are encapsulated in a transparent container and sent to the network in the MeasurementReportAppLayer message, as specified in
TS 38.331. The UE can send multiple application layer measurement reports to the gNB in one MeasurementReportAppLayer message. In order to allow the transmission of application layer measurement reports which exceed the maximum PDCP SDU size, segmentation of the MeasurementReportAppLayer message may be enabled by the gNB. An RRC identifier conveyed in the RRC signalling is used to identify the application layer measurement configuration and report between the gNB and the UE. The RRC identifier is mapped to the QoE reference in the gNB, and the gNB forwards the application layer measurement report to MCE together with the QoE reference. The gNB can release one or multiple application layer measurement configurations from the UE in one RRCReconfiguration message at any time. The UE may additionally be configured by the gNB to report when a QoE measurement session starts or stops for a certain application layer measurement configuration.
The QoE Measurement Collection deactivation permanently stops all or some of the QoE measurement collection jobs towards a UE, resulting in the release of the corresponding QoE measurement configuration(s) in the UE. The deactivation of QoE measurement collection is supported by using UE-associated signalling. A list of QoE references is used to deactivate the corresponding QoE measurement collection job(s).
Upon reception of the QoE release message in an application layer measurement configuration, the UE discards any unsent application layer measurement reports corresponding to the released application layer configuration. The UE discards the reports received from application layer when it has no associated application layer measurement configuration configured.
The network can replace a QoE measurement configuration with another one by deactivating an existing QoE measurement configuration and activating another QoE measurement configuration of the same QoE measurement configuration type.
The QoE measurement collection pause/resume procedure is used to pause/resume reporting of one or multiple QoE measurement configurations in a UE in RAN overload situation.
The gNB can use the RRCReconfiguration message to temporarily stop the UE from sending application layer measurement reports associated with one or multiple application layer measurement configurations. When the UE receives the QoE measurement collection pause indication, the UE temporarily stores application layer measurement reports in AS layer. When the UE receives the QoE measurement collection resume indication, the UE sends the stored application layer measurement reports to the gNB.
If the UE enters RRC_INACTIVE, the UE AS configuration for the QoE is stored in the UE Inactive AS context.
If the UE enters RRC_IDLE state, the UE releases all application layer measurement configurations.
When a service is provided within a configured slice, the QoE Measurement for this service type can also be configured together with the corresponding slice scope, so that the user experience of this service can also be evaluated on a per-slice basis. Multiple QoE measurement configurations can be configured for the same service type, and each configuration can pertain to different slices, where each QoE measurement configuration is identified with a QoE reference.
The UE includes the network slice identifier inside the QoE report container when reporting QoE measurement reports.