Section: 16.1.6.2 Redundant data transmission via single UPF and single RAN node
Content: Two NG-U tunnels are setup between single UPF and single NG-RAN node for redundant transmission of the QoS flows when PDU session setup or modification is initiated. The two NG-U tunnels are transferred via disjointed transport layer paths. The 5GC provides the indicator per QoS flow to the NG-RAN for the redundant transmission. For downlink, the NG-RAN node eliminates the duplicated packets per QoS flow. For uplink, the NG-RAN node replicates the packets and transmits them via the two NG-U tunnels. The indicator per QoS flow for redundant transmission is transferred to the target NG-RAN node in case of handover.