ETSI TS 138 304 V17.2.0 (2022-10)

5G; NR; User Equipment (UE) procedures in idle mode and in RRC Inactive state (3GPP TS 38.304 version 17.2.0 Release 17)

RTS/TSGR-0238304vh20

General Information

• Status: Not Published
• Technical Committee: 3GPP RAN 2 - Radio layer 2 specification and Radio layer 3 RR specification
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 20-Oct-2022

Standards Content (Sample)

ETSI TS 138 304 V17.2.0 (2022-10)






TECHNICAL SPECIFICATION
5G;
NR;
User Equipment (UE)
procedures in idle mode and in RRC Inactive state
(3GPP TS 38.304 version 17.2.0 Release 17)

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3GPP TS 38.304 version 17.2.0 Release 17 1 ETSI TS 138 304 V17.2.0 (2022-10)

Reference
RTS/TSGR-0238304vh20
Keywords
5G
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ETSI

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3GPP TS 38.304 version 17.2.0 Release 17 2 ETSI TS 138 304 V17.2.0 (2022-10)
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ETSI

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3GPP TS 38.304 version 17.2.0 Release 17 3 ETSI TS 138 304 V17.2.0 (2022-10)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 6
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 General description of RRC_IDLE state and RRC_INACTIVE state . 9
4.1 Overview . 9
4.2 Functional division between AS and NAS in RRC_IDLE state and RRC_INACTIVE state . 12
4.3 Service types in RRC_IDLE state . 15
4.4 Service types in RRC_INACTIVE state . 15
4.5 Cell Categories . 15
5 Process and procedure descriptions . 16
5.1 PLMN selection and SNPN selection . 16
5.1.1 Support for PLMN selection . 16
5.1.1.1 General . 16
5.1.1.2 NR case . 17
5.1.1.3 E-UTRA case . 17
5.1.2 Support for SNPN selection . 17
5.1.2.1 General . 17
5.1.2.2 NR case . 17
5.2 Cell selection and reselection . 17
5.2.1 Introduction. 17
5.2.2 States and state transitions in RRC_IDLE state and RRC_INACTIVE state . 18
5.2.3 Cell Selection process . 19
5.2.3.1 Description . 19
5.2.3.2 Cell Selection Criterion . 20
5.2.3.3 E-UTRAN case in Cell Selection . 21
5.2.4 Cell Reselection evaluation process . 21
5.2.4.1 Reselection priorities handling . 21
5.2.4.2 Measurement rules for cell re-selection . 23
5.2.4.3 Mobility states of a UE . 24
5.2.4.3.0 Introduction . 24
5.2.4.3.1 Scaling rules . 25
5.2.4.4 Cells with cell reservations, access restrictions or unsuitable for normal camping. 25
5.2.4.5 NR Inter-frequency and inter-RAT Cell Reselection criteria . 26
5.2.4.6 Intra-frequency and equal priority inter-frequency Cell Reselection criteria . 27
5.2.4.7 Cell reselection parameters in system information broadcasts . 27
5.2.4.7.0 General reselection parameters . 27
5.2.4.7.1 Speed dependent reselection parameters . 30
5.2.4.8 Inter-RAT Cell reselection in RRC_INACTIVE state . 30
5.2.4.9 Relaxed measurement . 30
5.2.4.9.0 Relaxed measurement rules . 30
5.2.4.9.1 Relaxed measurement criterion for UE with low mobility . 32
5.2.4.9.2 Relaxed measurement criterion for UE not at cell edge . 32
5.2.4.9.3 Relaxed measurement criterion for a stationary RedCap UE . 33
5.2.4.9.4 Relaxed measurement criterion for a stationary RedCap UE not at cell edge . 33
5.2.4.10 Cell reselection with CAG cells . 33
5.2.4.11 Reselection priorities for slice-based cell reselection. 33
5.2.5 Camped Normally state . 34
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3GPP TS 38.304 version 17.2.0 Release 17 4 ETSI TS 138 304 V17.2.0 (2022-10)
5.2.6 Selection of cell at transition to RRC_IDLE or RRC_INACTIVE state . 34
5.2.7 Any Cell Selection state . 35
5.2.8 Camped on Any Cell state . 35
5.3 Cell Reservations and Access Restrictions . 35
5.3.0 Introduction. 35
5.3.1 Cell status and cell reservations . 36
5.3.2 Unified access control . 38
5.4 Tracking Area registration . 38
5.5 RAN Area registration . 39
6 Reception of broadcast information . 39
6.1 Reception of system information . 39
6.2 Reception of MBS . 39
7 Paging . 40
7.1 Discontinuous Reception for paging . 40
7.2 Paging Early Indication . 42
7.2.1 Paging Early Indication reception . 42
7.3 Subgrouping . 43
7.3.0 General . 43
7.3.1 CN assigned subgrouping . 43
7.3.2 UE_ID based subgrouping . 43
7.4 Paging in extended DRX . 44
8 Sidelink Operation . 45
8.1 NR sidelink communication, and V2X sidelink communication, and NR sidelink discovery . 45
8.2 Cell selection and reselection for Sidelink . 45
8.2.1 Parameters used for cell selection and reselection triggered for sidelink . 46
9 Tracking Reference Signal . 46
Annex A (informative): Example of Hashed ID Calculation using 32-bit FCS . 47
Annex B (informative): Change history . 48
History . 51

ETSI

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3GPP TS 38.304 version 17.2.0 Release 17 5 ETSI TS 138 304 V17.2.0 (2022-10)
Foreword
This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
ETSI

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3GPP TS 38.304 version 17.2.0 Release 17 6 ETSI TS 138 304 V17.2.0 (2022-10)
1 Scope
The present document specifies the Access Stratum (AS) part of the UE procedures in RRC_IDLE state (also called Idle
mode) and RRC_INACTIVE state. The non-access stratum (NAS) part of Idle mode procedures and processes is
specified in TS 23.122 [9].
The present document specifies the model for the functional division between the NAS and AS in a UE.
The present document applies to all UEs that support at least NR Radio Access, including multi-RAT UEs as described
in 3GPP specifications, in the following cases:
- When the UE is camped on a NR cell;
- When the UE is searching for a cell to camp on;
NOTE: When the UE is camped on or searching for a cell to camp on belonging to other RATs, the UE behaviour
is described in the specifications of the other RATs.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- 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 in the same
Release as the present document.
[1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 38.300: "NR Overall Description; Stage 2".
[3] 3GPP TS 38.331: "NR; Radio Resource Control (RRC) - Protocol Specification".
[4] 3GPP TS 38.213: "NR; Physical layer procedures for control ".
[5] Void
[6] 3GPP TS 36.331: "E-UTRA; Radio Resource Control (RRC) - Protocol Specification".
[7] 3GPP TS 36.304: "E-UTRA; User Equipment (UE) procedures in RRC_IDLE state ".
[8] 3GPP TS 38.133: "NR; Requirements for Support of Radio Resource Management".
[9] 3GPP TS 23.122: "NAS functions related to Mobile Station (MS) in RRC_IDLE state".
[10] 3GPP TS 23.501: "System Architecture for the 5G System; Stage 2".
[11] 3GPP TS 38.215: "NR; Physical layer measurements".
[12] 3GPP TS 22.261: "Service requirements for the 5G system".
[13] 3GPP TS 24.890: "5G System – Phase 1; CT WG1 Aspects".
[14] 3GPP TS 24.501: "Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3".
[15] 3GPP TS 38.101-1: "NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1
Standalone".
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3GPP TS 38.304 version 17.2.0 Release 17 7 ETSI TS 138 304 V17.2.0 (2022-10)
[16] 3GPP TS 23.287: "Architecture enhancements for 5G System (5GS) to support Vehicle-to-
Everything (V2X) services".
[17] 3GPP TS 23.285: "Technical Specification Group Services and System Aspects; Architecture
enhancements for V2X services".
[18] 3GPP TS 22.011: "Service accessibility".
[19] 3GPP TS 38.321: "NR; Medium Access Control (MAC); Protocol specification".
[20] 3GPP TS 26.346: "Multimedia Broadcast/Multicast Service (MBMS); Protocols and codecs".
[21] 3GPP TS 23.247: "Architectural enhancements for 5G multicast-broadcast services; Stage 2".
[22] 3GPP TS 23.304: "Proximity based Services (ProSe) in 5G Systems (5GS)".
[23] 3GPP TS 23.003: "Numbering, addressing and identification".
[24] 3GPP TS 38.306: "User Equipment (UE) radio access capabilities".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Acceptable Cell: A cell that satisfies certain conditions as specified in 4.5.
Allowed CAG list: A per-PLMN list of CAG Identifiers the UE is allowed to access (see TS 23.501 [10]).
Available PLMN(s): One or more PLMN(s) for which the UE has found at least one cell and read its PLMN
identity(ies).
Available SNPN(s): One or more SNPN(s) for which the UE has found at least one cell and read its SNPN
identity(ies).
Barred Cell: A cell a UE is not allowed to camp on.
CAG cell: A cell broadcasting at least one Closed Access Group Identifier.
Camped on a cell: UE has completed the cell selection/reselection process and has chosen a cell. The UE monitors
system information and (in most cases) paging information.
Camped on any cell: UE is in idle mode and has completed the cell selection/reselection process and has chosen a cell
irrespective of PLMN identity.
Closed Access Group Identifier: Identifier of a CAG within a PLMN.
Commercial Mobile Alert System: Public Warning System that delivers Warning Notifications provided by Warning
Notification Providers to CMAS capable UEs.
eCall Only Mode: A UE configuration option that allows the UE to register at 5GC and register in IMS to perform only
eCall Over IMS, and a non-emergency IMS call for test and/or terminal reconfiguration services.
EHPLMN: Any of the PLMN entries contained in the Equivalent HPLMN list TS 23.122 [9].
Equivalent PLMN list: List of PLMNs considered as equivalent by the UE for cell selection, cell reselection, and
handover according to the information provided by the NAS.
Home PLMN: A PLMN where the Mobile Country Code (MCC) and Mobile Network Code (MNC) of the PLMN
identity are the same as the MCC and MNC of the IMSI.
HSDN cell: A cell that has higher priority than other cells for cell reselection for HSDN capable UE in a High-mobility
state.
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3GPP TS 38.304 version 17.2.0 Release 17 8 ETSI TS 138 304 V17.2.0 (2022-10)
Network Identifier: Identifier of an SNPN in combination with a PLMN ID (TS 23.501 [10]).
Non-Public Network: A network deployed for non-public use, as defined in TS 22.261 [12].
Non-terrestrial network: An NG-RAN consisting of gNBs, which provides non-terrestrial NR access to UEs by means
of an NTN payload embarked on an airborne or space-borne NTN vehicle and an NTN Gateway.
NR sidelink communication: AS functionality enabling at least V2X Communication as defined in TS 23.287 [16],
between two or more nearby UEs, using NR technology but not traversing any network node.
Process: A local action in the UE invoked by an RRC procedure or an RRC_IDLE or RRC_INACTIVE state
procedure.
Quasi-earth fixed cell: An NTN cell fixed with respect to a certain geographic area on the earth during a certain time
duration. This can be provisioned by beam(s) covering one geographic area for a limited period and a different
geographic area during another period (e.g., the case of NGSO satellites generating steerable beams).
Radio Access Technology: Type of technology used for radio access, for instance NR or E-UTRA.
RedCap UE: A UE with reduced capabilities as specified in clause 4.2.21 in TS 38.306 [24].
Registration Area: (NAS) registration area is an area in which the UE may roam without a need to perform location
registration, which is a NAS procedure.
Registered PLMN: This is the PLMN on which certain Location Registration outcomes have occurred, as specified in
TS 23.122 [9].
Registered SNPN: This is the SNPN on which certain Location Registration outcomes have occurred, as specified in
TS 23.122 [9].
Reserved Cell: A cell on which camping is not allowed, except for particular UEs, if so indicated in the system
information.
Selected PLMN: This is the PLMN that has been selected by the NAS, either manually or automatically.
Selected SNPN: This is the SNPN that has been selected by the NAS, either manually or automatically.
Serving cell: The cell on which the UE is camped.
Sidelink: UE to UE interface for V2X sidelink communication defined in TS 23.287[16].
SNPN Access Mode: Mode of operation wherein UE only selects SNPNs (as defined in TS 23.501 [10]).
SNPN identity: An identifier of an SNPN comprising of a PLMN ID and an NID combination.
Strongest cell: The cell on a particular frequency that is considered strongest according to the layer 1 cell search
procedure (TS 38.213 [4], TS 38.215 [11]).
Suitable Cell: This is a cell on which a UE may camp. For NR cell, the criteria are defined in clause 4.5, for E-UTRA
cell in TS 36.304 [7].
U2N Relay UE: a UE that provides functionality to support connectivity to the network for U2N Remote UE(s).
U2N Remote UE: a UE that communicates with the network via a U2N Relay UE.
V2X sidelink communication: AS functionality enabling V2X Communication as defined in TS 23.285 [17], between
nearby UEs, using E-UTRA technology but not traversing any network node.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An
abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in
TR 21.905 [1].
AS Access Stratum
CAG Closed Access Group
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3GPP TS 38.304 version 17.2.0 Release 17 9 ETSI TS 138 304 V17.2.0 (2022-10)
CAG-ID Closed Access Group Identifier
CMAS Commercial Mobile Alert System
CN Core Network
DCI Downlink Control Information
DRX Discontinuous Reception
eDRX Extended DRX
ETWS Earthquake and Tsunami Warning System
E-UTRA Evolved UMTS Terrestrial Radio Access
E-UTRAN Evolved UMTS Terrestrial Radio Access Network
GIN Group ID for Network selection
H-SFN Hyper System Frame Number
HRNN Human-Readable Network Name
HSDN High Speed Dedicated Network
IAB Integrated Access and Backhaul
IMSI International Mobile Subscriber Identity
MBS Multicast/Broadcast Services
MBS FSAI MBS Frequency Selection Area Identity
MCC Mobile Country Code
MCCH MBS Control Channe
...