Following are the functions performed by RRC layer in 5G NR protocol stack.
* Broadcast SI (System Information) messages to AS (Access Stratum) and NAS (Non-Access Stratum).
* Handles paging initiated by 5GC (5G Core Network) or NG-RAN (Radio Access Network).
* Establishment, maintenance and release of RRC Connection between 5G NR UE and NG-RAN. This includes addition, modification and release of CA(carrier aggregation) and Dual connectivity in NR or between E-UTRA and NR.
* Security related functions including key management
* Establishment, configuration, maintenance and release of SRBs (Signaling Radio Bearers) and DRBs (Data Radio Bearers).
* Mobility functions such as handover, context transfer, UE cell selection/re-selection, control of cell selection/re-selection, Inter-RAT mobility etc.
* QoS management
* UE measurement reporting, control of reporting
* Detection of radio link failure and recovery from radio link failure
* NAS message transfer to/from NAS from/to UE
