Abstract: The data link layer ... (RLC), and medium access control (MAC). Connectivity to a data network through 5G‐NR radio access and the 5G Core network is provided by a packet data unit session.

The CU contains both CU-C & CU-U functionality and supports PDCP,GTPU,RRC & S1AP protocols along with S1, F1 & E2 interfaces. The DU has High-PHY(FAPI), MAC, RLC & RRC (for handing RRC Config messages ...

openair1 : 3GPP LTE Rel-10/12 PHY layer / 3GPP NR Rel-15 layer ... openair2 : 3GPP LTE Rel-10 RLC/MAC/PDCP/RRC/X2AP + LTE Rel-14 M2AP implementation. Also 3GPP NR Rel-15 RLC/MAC/PDCP/RRC/X2AP. │ ├── ...