NG-RAN; NR user plane protocol
The present document specifies the NR user plane protocol functions used within NG-RAN and, for EN-DC and LTE UP-CP split within E-UTRAN. NR user plane protocol functions may reside in nodes terminating either the X2-U (for EN-DC) or the Xn-U or the F1-U interface. User plane protocol functions support both E-UTRA PDCP and NR PDCP.