CU¶
As outlined in the Knowledge Base section discussing the CU, the CU is split into the control plane (CU-CP) and the user plane (CU-UP). The srsRAN Project CU follows the architecture seen in the Knowledge Base.
CU-CP¶
As multiple DUs can be connected to the CU-CP, the F1AP, PDCP, and RRC are bundled into the so called DU processor that is created for each connected DU. Likewise multiple CU-UPs can be connected to the CU-CP, so the E1AP is created inside the CU-UP processor for each connected CU-UP.
Components:
E1AP-CU-CP: The CU-CP specific implementation of the E1AP
F1AP-CU: The CU specific implementation of the F1AP
PDCP: Packet Data Convergence Protocol
RRC: Radio Resource Control
NGAP: The CU specific implementation of the NGAP
Interfaces: