 QoS Flow-related measurements, including setup and release statistics per cause; RRC connection establishment and re-establishment-related measurements, including number of successful and failed establishment requests; PDCP data volume measurements; Packet loss/drop rate; IP level throughput and latency measurements. Two methods are defined in 3GPP TS 28.550 for the performance data reporting: Performance data file method: In this method the performance data are accumulated for a certain time before they are reported; the data will be delivered as a file. This method has been defined already in 3G and 4G. Performance data streaming method: In this method, the performance data streaming producer sends the performance data to the stream target when the data are ready. The stream target can be the consumer of the service or another network node. The volume of the performance data reported by streaming is expected to be small, and the Granularity Period9 of the performance data stream is configurable and may be significantly shorter than with the performance data file method. 3GPP TS 28.554 defines E2E KPIs. Special attention was paid to supporting in RAN the measurements contributing to computation of the E2E KPIs. The following KPIs are defined, grouped by categories: Accessibility KPIs; - Registered subscribers of network and NSI through AMF; 9 Time interval between consequent performance measurements. 6 Enabling Technologies - Registered subscribers of network and NSI through unified date management (UDM); - Registration success rate of one single NSI; - DRB accessibility for UE services; Integrity KPIs: - E2E latency of 5G network; - Downlink latency in gNB-DU; - Upstream throughput for network and NSI; - Downstream throughput for single NSI; - Upstream throughput at N3 interface; - Downstream throughput at N3 interface; - RAN UE throughput; Utilization KPIs: - Mean number of PDU sessions of network and NSI; - Virtualized resource utilization of NSI; Retainability KPI; - QoS flow retainability. The E2E KPIs can