Radio Resource Control (RRC) in 5G NR

Figure 1. Protocol Stack for U-plane and C-plane messages in 5G NR (Ref. 5G NR by E. Dahlman et al.)

Before discussing RRC directly, let us build some context!

In the 5G NR, Data and Control planes are clearly segregated.

The Data or User plane (U-plane) is responsible for carrying user data via protocol stack as shown in Figure 1 (i.e. SDAP, PDCP, RLC, MAC, PHY).

The Control plane (C-plane) is further divided into two categories: