Section: 4.4 Functions
Content: The RRC protocol includes the following main functions: - Broadcast of system information: - Including NAS common information; - Information applicable for UEs in RRC_IDLE and RRC_INACTIVE (e.g. cell (re-)selection parameters, neighbouring cell information) and information (also) applicable for UEs in RRC_CONNECTED (e.g. common channel configuration information); - Including ETWS notification, CMAS notification; - Including positioning assistance data. - RRC connection control: - Paging; - Establishment/modification/suspension/resumption/release of RRC connection, including e.g. assignment/modification of UE identity (C-RNTI, fullI-RNTI, etc.), establishment/modification/suspension/resumption/release of SRBs (except for SRB0); - Access barring; - Initial AS security activation, i.e. initial configuration of AS integrity protection (SRBs, DRBs) and AS ciphering (SRBs, DRBs); - RRC connection mobility including e.g. intra-frequency and inter-frequency handover, path switch from a PCell to a target L2 U2N Relay UE or from a L2 U2N Relay UE to a target PCell or from a source L2 U2N Relay UE to a target L2 U2N Relay UE, associated AS security handling, i.e. key/algorithm change, specification of RRC context information transferred between network nodes; - Establishment/modification/suspension/resumption/release of RBs carrying user data (DRBs/MRBs); - Radio configuration control including e.g. assignment/modification of ARQ configuration, HARQ configuration, DRX configuration; - In case of DC, cell management including e.g. change of PSCell, addition/modification/release of SCG cell(s); - In case of CA, cell management including e.g. addition/modification/release of SCell(s); - In case of MP, path management including e.g. addition/modification/release of indirect path; - QoS control including assignment/ modification of semi-persistent scheduling (SPS) configuration and configured grant configuration for DL and UL respectively, assignment/ modification of parameters for UL rate control in the UE, i.e. allocation of a priority and a prioritised bit rate (PBR) for each RB of UE and logical channel of IAB-MT. - Recovery from radio link failure. - Inter-RAT mobility including e.g. AS security activation, transfer of RRC context information; - Measurement configuration and reporting: - Establishment/modification/release of measurement configuration (e.g. intra-frequency, inter-frequency and inter- RAT measurements); - Setup and release of measurement gaps; - Measurement reporting. - Configuration of BAP entity and BH RLC channels for the support of IAB-node. - Configuration of SRAP entity and Uu/PC5 Relay RLC channels for the support of L2 U2N relay. - Other functions including e.g. generic protocol error handling, transfer of dedicated NAS information, transfer of UE radio access capability information. - Support of self-configuration and self-optimisation. - Support of measurement logging and reporting for network performance optimisation, as specified in TS 37.320[ Radio measurement collection for Minimization of Drive Tests (MDT); Overall description; Stage 2 ]  [61]; - Support of transfer of application layer measurement configuration and reporting. - Configuration of side control information for NCR-node.