Merge branch 'split-document' into 'main'

\sectionnum{References}

The following documents contain provisions which, through reference in

this text, constitute provisions of the present document.

\begin{itemize}

	\item[-] References are either specific (identified by date of publication,	edition number, version number, etc.) or non-specific.

	\item[-] For a specific reference, subsequent revisions do not apply.

	\item[-] For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document \emph{in the same Release as the present document}.

\end{itemize}

\insertreference{

	\item 3GPP TR 21.905: ``Vocabulary for 3GPP Specifications''.

	\item 3GPP TS 38.300: ``NR; Overall description; Stage 2''.

	\item 3GPP TS 38.321: ``NR; Medium Access Control (MAC); Protocol specification''.

	\item 3GPP TS 38.322: ``NR; Radio Link Control (RLC) protocol specification''.

	\item 3GPP TS 38.323: ``NR; Packet Data Convergence Protocol (PDCP) protocol specification''.

	\item ITU-T Recommendation X.680 (08/2015) ``Information Technology --Abstract Syntax Notation One (ASN.1): Specification of basic notation'' (Same as the ISO/IEC International Standard 8824-1).

	\item ITU-T Recommendation X.681 (08/2015) ``Information Technology --Abstract Syntax Notation One (ASN.1): Information object specification'' (Same as the ISO/IEC International Standard 8824-2).

	\item ITU-T Recommendation X.691 (08/2015) ``Information technology --ASN.1 encoding rules: Specification of Packed Encoding Rules (PER)'' (Same as the ISO/IEC International Standard 8825-2).

	\item 3GPP TS 38.215: ``NR; Physical layer measurements''.

	\item 3GPP TS 36.331: ``Evolved Universal Terrestrial Radio Access (E-UTRA) Radio Resource Control (RRC); Protocol Specification''.

	\item 3GPP TS 33.501: ``Security Architecture and Procedures for 5G System''.

	\item 3GPP TS 38.104: ``NR; Base Station (BS) radio transmission and reception''.

	\item 3GPP TS 38.213: ``NR; Physical layer procedures for control''.

	\item 3GPP TS 38.133: ``NR; Requirements for support of radio resource management''.

	\item 3GPP TS 38.101-1: ``NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone''.

	\item 3GPP TS 38.211: ``NR; Physical channels and modulation''.

	\item 3GPP TS 38.212: ``NR; Multiplexing and channel coding''.

	\item ITU-T Recommendation X.683 (08/2015) ``Information Technology --Abstract Syntax Notation One (ASN.1): Parameterization of ASN.1 specifications'' (Same as the ISO/IEC International Standard 8824-4).

	\item 3GPP TS 38.214: ``NR; Physical layer procedures for data''.

	\item 3GPP TS 38.304: ``NR; User Equipment (UE) procedures in Idle mode and RRC Inactive state''.

	\item 3GPP TS 23.003: ``Numbering, addressing and identification''.

	\item 3GPP TS 36.101: ``E-UTRA; User Equipment (UE) radio transmission and reception''.

	\item 3GPP TS 24.501: ``Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3''.

	\item 3GPP TS 37.324: ``Service Data Adaptation Protocol (SDAP) specification''.

	\item 3GPP TS 22.261: ``Service requirements for the 5G System''.

	\item 3GPP TS 38.306: ``User Equipment (UE) radio access capabilities''.

	\item 3GPP TS 36.304: ``E-UTRA; User Equipment (UE) procedures in idle mode''.

	\item ATIS 0700041: ``WEA 3.0: Device-Based Geo-Fencing''.

	\item 3GPP TS 23.041: ``Technical realization of Cell Broadcast Service (CBS)''.

	\item 3GPP TS 33.401: ``3GPP System Architecture Evolution (SAE); Security architecture''.

	\item 3GPP TS 36.211: ``E-UTRA; Physical channels and modulation''.

	\item 3GPP TS 23.501: ``System Architecture for the 5G System; Stage 2''.

	\item 3GPP TS 36.104: ``E-UTRA; Base Station (BS) radio transmission and reception''.

	\item 3GPP TS 38.101-3 ``NR; User Equipment (UE) radio transmission and reception; Part 3: Range 1 and Range 2 Interworking operation with other radios''.

	\item 3GPP TS 38.423: ``NG-RAN, Xn application protocol (XnAP)''.

	\item 3GPP TS 38.473: ``NG-RAN; F1 application protocol (F1AP)''.

	\item 3GPP TS 36.423: ``E-UTRA; X2 application protocol (X2AP)''.

	\item 3GPP TS 24.008: ``Mobile radio interface layer 3 specification; Core network protocols; Stage 3''.

	\item 3GPP TS 38.101-2 ``NR; User Equipment (UE) radio transmission and reception; Part 2: Range 2 Standalone''.

	\item 3GPP TS 36.133: ``E-UTRA; Requirements for support of radio resource management''.

	\item 3GPP TS 37.340: ``E-UTRA and NR; Multi-connectivity; Stage 2''.

	\item 3GPP TS 38.413: ``NG-RAN, NG Application Protocol (NGAP)''.

	\item 3GPP TS 23.502: ``Procedures for the 5G System; Stage 2''.

	\item 3GPP TR 36.816: ``Evolved Universal Terrestrial Radio Access (E-UTRA); Study on signalling and procedure for interference avoidance for in-device coexistence ''.

	\item 3GPP TS 25.331: ``Universal Terrestrial Radio Access (UTRA); Radio Resource Control (RRC); Protocol specification''.

	\item 3GPP TS 25.133: ``Requirements for Support of Radio Resource Management (FDD)''.

	\item 3GPP TS 38.340: ``Backhaul Adaptation Protocol (BAP) specification''.

	\item 3GPP TS 37.213: ``Physical layer procedures for shared spectrum channel access''.

	\item 3GPP TS 37.355: ``LTE Positioning Protocol (LPP)''.

	\item IEEE 802.11-2012, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, IEEE Std.

	\item Bluetooth Special Interest Group: ``Bluetooth Core Specification v5.0'', December 2016.

	\item 3GPP TS 32.422: ``Telecommunication management; Subscriber and equipment trace; Trace control and configuration management''.

	\item 3GPP TS 38.314: ``NR; layer 2 measurements''.

	\item Void.

	\item 3GPP TS 23.287: ``Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services''.

	\item 3GPP TS 23.285: ``Technical Specification Group Services and System Aspects; Architecture enhancements for V2X services''.

	\item 3GPP TS 24.587: ``Technical Specification Group Core Network and Terminals; Vehicle-to-Everything (V2X) services in 5G System (5GS)''.

	\item Military Standard WGS84 Metric MIL-STD-2401 (11 January 1994): ``Military Standard Department of Defence World Geodetic System (WGS)''.

	\item 3GPP TS 38.101-4 ``NR; User Equipment (UE) radio transmission and reception; Part 4: Performance Requirements''.

	\item 3GPP TS 33.536: ``Technical Specification Group Services and System Aspects; Security aspects of 3GPP support for advanced Vehicle-to-Everything (V2X) services''.

	\item 3GPP TS 37.320: ``Radio measurement collection for Minimization of Drive Tests (MDT); Overall description; Stage 2''.

	\item 3GPP TS 36.306: ``User Equipment (UE) radio access capabilities''.

	\item 3GPP TS 38.174: ``NR; Integrated Access and Backhaul (IAB) radio transmission and reception''.

	\item 3GPP TS 38.472: ``NG-RAN; F1 signalling transport''.

	\item 3GPP TS 23.304: ``Proximity based Services (ProSe) in the 5G System (5GS)''.

	\item 3GPP TS 38.351: ``NR; Sidelink Relay Adaptation Protocol (SRAP) Specification''.

	\item 3GPP TS 23.247: ``Architectural enhancements for 5G multicast-broadcast services; Stage 2''.

	\item 3GPP TS 26.247: ``Transparent end-to-end Packet-switched Streaming Service (PSS); Progressive Download and Dynamic Adaptive Streaming over HTTP (3GP-DASH)''.

	\item 3GPP TS 26.114: ``IP Multimedia Subsystem (IMS); Multimedia Telephony; Media handling and interaction''.

	\item 3GPP TS 26.118: ``Virtual Reality (VR) profiles for streaming applications''.

	\item NIMA TR 8350.2, Third Edition, Amendment 1, 3 January 2000: ``DEPARTMENT OF DEFENSE WORLD GEODETIC SYSTEM 1984''.

	\item 3GPP TS 24.554: ``Technical Specification Group Core Network and Terminals; Proximity-services (ProSe) in 5G System (5GS) protocol''.

	\item 3GPP TS 38.305: ``NG Radio Access Network (NG-RAN); Stage 2 functional specification of User Equipment (UE) positioning in NG-RAN''.

	\item 3GPP TS 23.122: ``Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode''.

	\item 3GPP TS 38.101-5: ``User Equipment (UE) radio transmission and reception; Part 5: Satellite access Radio Frequency (RF) and performance requirements''.

	\item 3GPP TS 23.256: ``Support of Uncrewed Aerial Systems (UAS) connectivity, identification and tracking; Stage 2''.

	\item 3GPP TS 38.355: ``NR; Sidelink Positioning Protocol (SLPP); Protocol Specification''.

	\item 3GPP TS 24.588: ``Technical Specification Group Core Network and Terminals; Vehicle-to-Everything (V2X) services in 5G System (5GS); User Equipment (UE) policies; Stage 3''.

	\item 3GPP TS 38.106: ``NR; NR Repeater Radio Transmission and Reception''.

	\item 3GPP TS 28.405: ``Technical Specification Group Services and 	System Aspects; Telecommunication management; Quality of Experience (QoE) measurement collection; Control and configuration''.	

}

 No newline at end of file

\sectionnum{General}

\subsection{Introduction}

This specification is organised as follows:

\begin{itemize}

	\item[-] clause 4.2 describes the RRC protocol model;

	\item[-] clause 4.3 specifies the services provided to upper layers as well as

	the services expected from lower layers;

	\item[-] clause 4.4 lists the RRC functions;

	\item[-] clause 5 specifies RRC procedures, including UE state transitions;

	\item[-] clause 6 specifies the RRC messages in ASN.1 and description;

	\item[-] clause 7 specifies the variables (including protocol timers and

	constants) and counters to be used by the UE;

	\item[-] clause 8 specifies the encoding of the RRC messages;

	\item[-] clause 9 specifies the specified and default radio configurations;

	\item[-] clause 10 specifies generic error handling;

	\item[-] clause 11 specifies the RRC messages transferred across network nodes;

	\item[-] clause 12 specifies the UE capability related constraints and

	performance requirements.

\end{itemize}

\subsection{Architecture}

\subsubsection{UE states and state transitions including inter RAT}

A UE is either in RRC\_CONNECTED state or in RRC\_INACTIVE state when an

RRC connection has been established. If this is not the case, i.e. no

RRC connection is established, the UE is in RRC\_IDLE state. The RRC

states can further be characterised as follows:

\begin{itemize}

	\item[-] \textbf{RRC\_IDLE:}

	\begin{itemize}

		\item[-] A UE specific DRX may be configured by upper layers;

		\item[-] At lower layers, the UE may be configured with a DRX for PTM

		transmission of MBS broadcast;

		\item[-] UE controlled mobility based on network configuration;

		\item[-] The UE:

		\item[-] Monitors Short Messages transmitted with P-RNTI over DCI (see clause

		6.5);

		\item[-] Monitors a Paging channel for CN paging using 5G-S-TMSI, except if the

		UE is acting as a L2 U2N Remote UE;

		\item[-] If configured by upper layers for MBS multicast reception, monitors a

		Paging channel for CN paging using TMGI;

		\item[-] Performs neighbouring cell measurements and cell (re-)selection;

		\item[-] Performs measurements on L2 U2N Relay UEs and relay (re-)selection;

		\item[-] Acquires system information and can send SI request (if configured);

		\item[-] Performs logging of available measurements together with location and

		time for logged measurement configured UEs;

		\item[-] Performs idle/inactive measurements for idle/inactive measurement

		configured UEs;

		\item[-] If configured by upper layers for MBS broadcast reception, acquires

		MCCH change notification and MBS broadcast control information and data.

	\end{itemize}

	\item[-] \textbf{RRC\_INACTIVE:}

	\begin{itemize}

		\item[-] A UE specific DRX may be configured by upper layers or by RRC layer;

		\item[-] At lower layers, the UE may be configured with a DRX for PTM

		transmission of MBS broadcast and/or a DRX for PTM transmission of MBS

		multicast;

		\item[-] UE controlled mobility based on network configuration;

		\item[-] The UE stores the UE Inactive AS context;

		\item[-] A RAN-based notification area is configured by RRC layer;

		\item[-] Transfer of unicast data and/or signalling to/from UE over radio

		bearers configured for SDT.

		\item[-] The UE:

		\item[-] Monitors Short Messages transmitted with P-RNTI over DCI (see clause

		6.5);

		\item[-] While T319a is running, monitors control channels associated with the

		shared data channel to determine if data is scheduled for it;

		\item[-] While SDT procedure is ongoing and T319a is not running, if CG-SDT is

		selected and if extended CG-SDT periodicity is configured (i.e.

		\emph{cg-SDT-PeriodicityExt} is configured), monitors a Paging channel

		for CN paging using 5G-S-TMSI and RAN paging using fullI-RNTI except if

		the UE is acting as a L2 U2N Remote UE;

		\item[-] While SDT procedure is not ongoing, monitors a Paging channel for CN

		paging using 5G-S-TMSI and RAN paging using fullI-RNTI, except if the UE

		is acting as a L2 U2N Remote UE;

		\item[-] If configured by upper layers for MBS multicast reception, while SDT

		procedure is not ongoing, monitors a Paging channel for paging using

		TMGI;

		\item[-] Performs neighbouring cell measurements and cell (re-)selection;

		\item[-] Performs measurements on L2 U2N Relay UEs and relay (re-)selection;

		\item[-] Performs RAN-based notification area updates periodically and when

		moving outside the configured RAN-based notification area;

		\item[-] Acquires system information and, while SDT procedure is not ongoing,

		can send SI request (if configured);

		\item[-] While SDT procedure is not ongoing, performs logging of available

		measurements together with location and time for logged measurement

		configured UEs;

		\item[-] While SDT procedure is not ongoing, performs idle/inactive

		measurements for idle/inactive measurement configured UEs;

		\item[-] If configured by upper layers for MBS broadcast reception, acquires

		MCCH change notification and MBS broadcast control information and data;

		\item[-] If configured for MBS multicast reception in RRC\_INACTIVE, acquires

		multicast MCCH change notification and MBS multicast control information

		and data;

		\item[-] Transmits SRS for Positioning.

	\end{itemize}

	\item[-] \textbf{RRC\_CONNECTED:}

	\begin{itemize}

		\item[-] The UE stores the AS context;

		\item[-] Transfer of unicast data to/from UE;

		\item[-] Transfer of MBS multicast data to UE;

		\item[-] At lower layers, the UE may be configured with a UE specific DRX;

		\item[-] At lower layers, the UE may be configured with a DRX for PTM

		transmission of MBS broadcast and/or a DRX for MBS multicast;

		\item[-] At lower layers, the UE may be configured with a cell specific cell

		DTX/DRX;

		\item[-] For UEs supporting CA, use of one or more SCells, aggregated with the

		SpCell, for increased bandwidth;

		\item[-] For UEs supporting DC, use of one SCG, aggregated with the MCG, for

		increased bandwidth;

		\item[-] Network controlled mobility within NR, to/from E-UTRA, and to

		UTRA-FDD;

		\item[-] Network controlled mobility (path switch) between a serving cell and a

		L2 U2N Relay UE, or vice versa, or between a source L2 U2N Relay UE and

		a target L2 U2N Relay UE;

		\item[-] Network controlled MP operation.

		\item[-] The UE:

		\item[-] Monitors Short Messages transmitted with P-RNTI over DCI (see clause

		6.5), if configured;

		\item[-] Monitors control channels associated with the shared data channel to

		determine if data is scheduled for it;

		\item[-] Provides channel quality and feedback information;

		\item[-] Performs neighbouring cell and/or L2 U2N relay measurements and

		measurement reporting;

		\item[-] Acquires system information;

		\item[-] Performs immediate MDT measurement together with available location

		reporting;

		\item[-] If configured by upper layers for MBS broadcast reception, acquires

		MCCH change notification and MBS broadcast control information and data.

	\end{itemize}

\end{itemize}

Figure 4.2.1-1 illustrates an overview of UE RRC state machine and state

transitions in NR. A UE has only one RRC state in NR at one time.

\insertcenterfigure{4.2.1-1}{UE state machine and state transitions in NR}

{0.5}{media/image3.png}

Figure 4.2.1-2 illustrates an overview of UE state machine and state

transitions in NR as well as the mobility procedures supported between

NR/5GC, E-UTRA/EPC and E-UTRA/5GC.

\insertcenterfigure{4.2.1-2}{UE state machine and state transitions between NR/5GC, E-UTRA/EPC and E-UTRA/5GC}

{0.8}{media/image4.png}

Figure 4.2.1-3 illustrates the mobility procedure supported between

NR/5GC and UTRA-FDD.

\insertcenterfigure{4.2.1-3}{Mobility procedure supported between NR/5GC and UTRA-FDD}

{0.8}{media/image5.png}

\subsubsection{Signalling radio bearers}

``Signalling Radio Bearers'' (SRBs) are defined as Radio Bearers (RBs)

that are used only for the transmission of RRC and NAS messages. More

specifically, the following SRBs are defined:

\begin{itemize}

	\item[-] SRB0 is for RRC messages using the CCCH logical channel (except SRB0

	of L2 U2N Remote UE);

	\item[-] SRB1 is for RRC messages (which may include a piggybacked NAS message)

	as well as for NAS messages prior to the establishment of SRB2, all

	using DCCH logical channel (except SRB1 of L2 U2N Remote UE);

	\item[-] SRB2 is for NAS messages and for RRC messages which include logged

	measurement information, all using DCCH logical channel (except SRB2 of

	L2 U2N Remote UE). SRB2 has a lower priority than SRB1 and may be

	configured by the network after AS security activation;

	\item[-] SRB3 is for specific RRC messages when UE is in (NG)EN-DC or NR-DC,

	all using DCCH logical channel;

	\item[-] SRB4 is for RRC messages which include application layer measurement

	report information, all using DCCH logical channel. SRB4 has a lower

	priority than SRB1 and can only be configured by the network after AS

	security activation.

	\item[-] SRB5 is for RRC messages which include application layer measurement

	report information, all using DCCH logical channel. SRB5 has a lower

	priority than SRB1 and SRB3 and can only be configured by the SN serving

	the SCG when the UE is in NR-DC, after AS security activation.

\end{itemize}

In downlink, piggybacking of NAS messages is used only for one dependant

(i.e. with joint success/failure) procedure: bearer

establishment/modification/release. In uplink piggybacking of NAS

message is used only for transferring the initial NAS message during

connection setup and connection resume.

\begin{notes}

	\item[NOTE 1:] The NAS messages transferred via SRB2 are also contained in RRC messages, which however do not include any RRC protocol control information.

\end{notes}

Once AS security is activated, all RRC messages on SRB1, SRB2, SRB3,

SRB4 and SRB5, including those containing NAS messages, are integrity

protected and ciphered by PDCP. NAS independently applies integrity

protection and ciphering to the NAS messages, see TS 24.501 {[}23{]}.

Split SRB is supported for all the MR-DC options as well as MP in both

SRB1 and SRB2 (split SRB is not supported for SRB0, SRB3, SRB4 and

SRB5).

For operation with shared spectrum channel access in FR1, SRB0, SRB1 and

SRB3 are assigned with the highest priority Channel Access Priority

Class (CAPC), (i.e. CAPC = 1) while CAPC for SRB2 is configurable.

For the NR sidelink L2 U2N relay operations not involved in MP, SRB0,

SRB1, SRB2 of a L2 U2N Remote UE are not using Uu CCCH/DCCH logical

channels. The SRB0, SRB1, SRB2 of a L2 U2N Remote UE are transmitted via

the PC5 Relay RLC channels over PC5 and Uu Relay RLC channels over Uu.

\subsection{Services}

\subsubsection{Services provided to upper layers}

The RRC protocol offers the following services to upper layers:

\begin{itemize}

	\item[-] Broadcast of common control information;

	\item[-] Notification of UEs in RRC\_IDLE, e.g. about a mobile terminating

	call;

	\item[-] Notification of UEs about ETWS and/or CMAS;

	\item[-] Transfer of dedicated signalling;

	\item[-] Broadcast of positioning assistance data;

	\item[-] Transfer of application layer measurement configuration and reporting.

\end{itemize}

\subsubsection{Services expected from lower layers}

In brief, the following are the main services that RRC expects from

lower layers:

\begin{itemize}

	\item[-] Integrity protection, ciphering and loss-less in-sequence delivery of

	information without duplication;

\end{itemize}

\subsection{Functions}

The RRC protocol includes the following main functions:

\begin{itemize}

	\item[-] Broadcast of system information:

	\item[-] Including NAS common information;

	\item[-] 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);

	\item[-] Including ETWS notification, CMAS notification;

	\item[-] Including positioning assistance data.

	\item[-] RRC connection control:

	\item[-] Paging;

	\item[-] 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);

	\item[-] Access barring;

	\item[-] Initial AS security activation, i.e. initial configuration of AS

	integrity protection (SRBs, DRBs) and AS ciphering (SRBs, DRBs);

	\item[-] 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;

	\item[-] Establishment/modification/suspension/resumption/release of RBs

	carrying user data (DRBs/MRBs);

	\item[-] Radio configuration control including e.g. assignment/modification of

	ARQ configuration, HARQ configuration, DRX configuration;

	\item[-] In case of DC, cell management including e.g. change of PSCell,

	addition/modification/release of SCG cell(s);

	\item[-] In case of CA, cell management including e.g.

	addition/modification/release of SCell(s);

	\item[-] In case of MP, path management including e.g.

	addition/modification/release of indirect path;

	\item[-] 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.

	\item[-] Recovery from radio link failure.

	\item[-] Inter-RAT mobility including e.g. AS security activation, transfer of

	RRC context information;

	\item[-] Measurement configuration and reporting:

	\item[-] Establishment/modification/release of measurement configuration (e.g.

	intra-frequency, inter-frequency and inter-RAT measurements);

	\item[-] Setup and release of measurement gaps;

	\item[-] Measurement reporting.

	\item[-] Configuration of BAP entity and BH RLC channels for the support of

	IAB-node.

	\item[-] Configuration of SRAP entity and Uu/PC5 Relay RLC channels for the

	support of L2 U2N relay.

	\item[-] Configuration of SRAP entity and PC5 Relay RLC channels for the

	support of L2 U2U relay operation.

	\item[-] Other functions including e.g. generic protocol error handling,

	transfer of dedicated NAS information, transfer of UE radio access

	capability information.

	\item[-] Support of self-configuration and self-optimisation.

	\item[-] Support of measurement logging and reporting for network performance

	optimisation, as specified in TS 37.320 {[}61{]};

	\item[-] Support of transfer of application layer measurement configuration and

	reporting.

	\item[-] Configuration of side control information for NCR-node.

\end{itemize}