ETSI TS 136 304 V15.5.0 (2020-01)

ETSI TS 136 304 V15.5.0 (2020-01)






TECHNICAL SPECIFICATION
LTE;
Evolved Universal Terrestrial Radio Access (E-UTRA);
User Equipment (UE) procedures in idle mode
(3GPP TS 36.304 version 15.5.0 Release 15)

---------------------- Page: 1 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 1 ETSI TS 136 304 V15.5.0 (2020-01)



Reference
RTS/TSGR-0236304vf50
Keywords
LTE
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2020.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners.
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 2 ETSI TS 136 304 V15.5.0 (2020-01)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found under http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

---------------------- Page: 3 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 3 ETSI TS 136 304 V15.5.0 (2020-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 6
3 Definitions and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 9
3.3 Abbreviations . 10
4 General description of Idle mode . 11
4.1 Overview . 11
4.2 Functional division between AS and NAS in Idle mode . 12
4.3 Service types in Idle Mode . 14
4.4 NB-IoT functionality in Idle Mode . 16
5 Process and procedure descriptions . 16
5.1 PLMN selection . 16
5.1.1 Void . 17
5.1.2 Support for PLMN selection . 17
5.1.2.1 General . 17
5.1.2.2 E-UTRA and NB-IoT case . 17
5.1.2.3 UTRA case . 17
5.1.2.4 GSM case . 17
5.1.2.5 CDMA2000 case . 17
5.1.2.6 NR case . 17
5.2 Cell selection and reselection . 18
5.2.1 Introduction. 18
5.2.2 States and state transitions in Idle Mode . 19
5.2.3 Cell Selection process . 20
5.2.3.1 Description . 20
5.2.3.2 Cell Selection Criterion . 21
5.2.3.2a Cell Selection Criterion for NB-IoT . 22
5.2.3.3 CSG cells and Hybrid cells in Cell Selection . 22
5.2.3.4 GSM case in Cell Selection . 23
5.2.3.5 UTRAN case in Cell Selection. 23
5.2.3.6 NR case in Cell Selection . 23
5.2.4 Cell Reselection evaluation process . 23
5.2.4.1 Reselection priorities handling . 23
5.2.4.2 Measurement rules for cell re-selection . 25
5.2.4.2a Measurement rules for cell re-selection for NB-IoT . 25
5.2.4.3 Mobility states of a UE . 25
5.2.4.3.1 Scaling rules . 26
5.2.4.4 Cells with cell reservations, access restrictions or unsuitable for normal camping. 27
5.2.4.5 E-UTRAN Inter-frequency and inter-RAT Cell Reselection criteria . 27
5.2.4.6 Intra-frequency and equal priority inter-frequency Cell Reselection criteria . 28
5.2.4.6a Reselection for enhanced coverage . 30
5.2.4.7 Cell reselection parameters in system information broadcasts . 30
5.2.4.7.1 Speed dependant reselection parameters . 32
5.2.4.8 Cell reselection with CSG cells . 33
5.2.4.8.1 Cell reselection from a non-CSG cell to a CSG cell . 33
5.2.4.8.2 Cell reselection from a CSG cell . 33
5.2.4.9 Cell reselection with Hybrid cells . 33
5.2.4.10 E-UTRAN Inter-frequency Redistribution procedure . 34
ETSI

---------------------- Page: 4 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 4 ETSI TS 136 304 V15.5.0 (2020-01)
5.2.4.10.1 Redistribution target selection . 34
5.2.4.11 Cell reselection or CN type change when storing UE AS context . 35
5.2.4.12 Relaxed monitoring . 35
5.2.4.12.0 Relaxed monitoring measurement rules . 35
5.2.4.12.1 Relaxed monitoring criterion . 35
5.2.4.13 Cell reselection or CN type change in RRC_INACTIVE state . 35
5.2.5 Void . 35
5.2.6 Camped Normally state . 35
5.2.7 Cell Selection at transition to RRC_IDLE or RRC_INACTIVE state . 36
5.2.7a Cell Selection when leaving RRC_CONNECTED state for NB-IoT . 36
5.2.8 Any Cell Selection state . 36
5.2.8a Any Cell Selection state for NB-IoT . 36
5.2.9 Camped on Any Cell state . 36
5.3 Cell Reservations and Access Restrictions . 37
5.3.1 Cell status and cell reservations . 37
5.3.2 Access control . 39
5.3.3 Emergency call . 39
5.4 Tracking Area registration . 39
5.5 Support for manual CSG selection . 40
5.5.1 E-UTRA case . 40
5.5.2 UTRA case. 40
5.6 RAN-assisted WLAN interworking . 40
5.6.1 RAN assistance parameter handling in RRC_IDLE . 40
5.6.2 Access network selection and traffic steering rules . 40
5.6.3 RAN assistance parameters definition . 41
6 Reception of broadcast information . 42
6.1 Reception of system information . 42
6.2 Reception of MBMS . 42
7 Paging . 43
7.1 Discontinuous Reception for paging . 43
7.2 Subframe Patterns. 44
7.3 Paging in extended DRX . 45
7.4 Paging with Wake Up Signal . 46
8 Logged measurements . 47
9 Accessibility measurements . 47
10 Mobility History Information . 47
11 Sidelink operation . 47
11.1 Sidelink communication and V2X sidelink communication . 47
11.2 Sidelink discovery . 48
11.3 Sidelink synchronisation . 48
11.4 Cell selection and reselection for sidelink . 48
11.4.1 Parameters used for cell selection and reselection triggered for sidelink . 48
12. General description of UE camping on E-UTRA connected to 5GC . 49
Annex A (informative): Void . 50
Annex B (informative): Example of Hashed ID Calculation using 32-bit FCS . 51
Annex C (informative): Change history . 52
History . 56

ETSI

---------------------- Page: 5 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 5 ETSI TS 136 304 V15.5.0 (2020-01)
Foreword
rd
This Technical Specification has been produced by the 3 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

---------------------- Page: 6 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 6 ETSI TS 136 304 V15.5.0 (2020-01)
1 Scope
The present document specifies the Access Stratum (AS) part of the Idle Mode procedures applicable to a UE. The non-
access stratum (NAS) part of Idle mode procedures and processes is specified in TS 23.122 [5].
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 E-UTRA, including multi-RAT UEs as described in 3GPP
specifications, in the following cases:
- When the UE is camped on an E-UTRA 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 RAT.
The Idle Mode procedures defined in this specification are also applicable for a UE in RRC_INACTIVE state unless
specified otherwise.
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 25.990: "Vocabulary for UTRAN".
[2] 3GPP TS 36.300: "E-UTRA and E-UTRAN Overall Description; Stage 2".
[3] 3GPP TS 36.331: "E-UTRA; Radio Resource Control (RRC) - Protocol Specification".
[4] 3GPP TS 22.011: "Service accessibility".
[5] 3GPP TS 23.122: "NAS functions related to Mobile Station (MS) in idle mode".
[6] 3GPP TS 36.213: "E-UTRA; Physical layer procedures".
[7] 3GPP TS 36.214: "E-UTRA; Physical layer; Measurements".
[8] 3GPP TS 25.304: "User Equipment (UE) procedures in idle mode and procedures for cell
reselection in connected mode"
[9] 3GPP TS 43.022: "Functions related to Mobile Station in idle mode and group receive mode".
[10] 3GPP TS 36.133: "Requirements for Support of Radio Resource Management".
[11] void
[12] void
[13] void
[14] void
[15] void
ETSI

---------------------- Page: 7 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 7 ETSI TS 136 304 V15.5.0 (2020-01)
[16] 3GPP TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage
3"
[17] 3GPP2 C.S0024-C v2.0: "cdma2000 High Rate Packet Data Air Interface Specification".
[18] 3GPP2 C.S0005-F v1.0: "Upper Layer (Layer 3) Signalling Standard for cdma2000 Spread
Spectrum Systems".
[19] 3GPP TS 25.304: "User Equipment (UE) procedures in idle mode and procedures for cell
reselection in connected mode".
[20] 3GPP TS 24.008: "Mobile Radio Interface Layer 3 specification; Core Network Protocols;
Stage 3"
[21] 3GPP TS 37.320: "Universal Terrestrial Radio Access (UTRA) and Evolved Universal Terrestrial
Radio Access (E-UTRA); Radio measurement collection for Minimization of Drive Tests (MDT);
Overall description; Stage 2".
[22] 3GPP TS 26.346: "Multimedia Broadcast/Multicast Service (MBMS); Protocols and codecs".
[23] 3GPP TS 23.401: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".
[24] 3GPP TS 23.682: "Architecture enhancements to facilitate communications with packet data
networks and applications".
[25] 3GPP TS 23.402: "Architecture enhancements for non-3GPP accesses".
[26] IEEE 802.11, Part 11: "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
specifications, IEEE Std.".
[27] Wi-Fi Alliance Technical Committee, Hotspot 2.0 Technical Task Group: "Hotspot 2.0 (Release 2)
Technical Specification".
[28] 3GPP TS 24.302: "Access to the 3GPP Evolved Packet Core (EPC) via non-3GPP access
networks".
[29] 3GPP TS 23.303: "Proximity-based services (ProSe); Stage 2".
[30] 3GPP TS 36.321: "E-UTRA; Medium Access Control (MAC) protocol specification".
[31] 3GPP TS 24.105: "Application specific Congestion control for Data Communication (ACDC)
Management Object (MO)".
[32] 3GPP TS 31.102: "Characteristics of the Universal Subscriber Identity Module (USIM)
application".
[33] 3GPP TS 36.101: "Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE)
radio transmission and reception".
[34] Void
[35] 3GPP TS 23.003: "Numbering, addressing and identification".
[36] 3GPP TS 23.285: "Technical Specification Group Services and System Aspects; Architecture
enhancements for V2X services".
[37] 3GPP TS 38.331: "NR; Radio Resource Control (RRC); Protocol specification".
[38] 3GPP TS 38.304: "New Generation Radio Access Network; User Equipment (UE) procedures in
Idle mode and RRC Inactive state".
[39] 3GPP TS 23.501: "System Architecture for the 5G System; Stage 2".
ETSI

---------------------- Page: 8 ----------------------
3GPP TS 36.304 version 15.5.0 Release 15 8 ETSI TS 136 304 V15.5.0 (2020-01)
3 Definitions 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 4.3. A UE can always attempt emergency calls
on an acceptable cell, but restriction as in 5.3.3 apply.
CSG Whitelist: A list provided by NAS containing all the CSG identities and their associated PLMN IDs of the CSGs
to which the subscriber belongs.
NOTE: This list is known as Allowed CSG List in Rel-8 Access Stratum specifications.
Available PLMN(s): One or more PLMN(s) for which the UE has found at least one cell and read its PLMN
identity(ies).
Barred Cell: A cell a UE is not allowed to camp on.
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 Subscriber Group (CSG): A Closed Subscriber Group identifies subscribers of an operator who are permitted
to access one or more cells of the PLMN but which have restricted access (CSG cells).
CN type: The type of core network connectivity supported by an E-UTRA cell, either EPC or 5GC.
Commercial Mobile Alert System: Public Warning System that delivers Warning Notifications provided by Warning
Notification Providers to CMAS capable UEs.
CSG cell: A cell broadcasting a CSG indication that is set to TRUE and a specific CSG identity.
CSG identity: An identifier broadcast by a CSG or hybrid cell/cells and used by the UE to facilitate access for
authorised members of the associated Closed Subscriber Group.
CSG member cell: a cell broadcasting the identity of the selected PLMN, registered PLMN or equivalent PLMN and
for which the CSG whitelist of the UE includes an entry comprising cell's CSG ID and the respective PLMN identity.
DRX cycle: Individual time interval between monitoring Paging Occasion for a specific UE.
eDRX cycle: Time interval between the first Paging Occasions occurring after successive extended DRX periods.
eCall Only Mode: A UE configuration option that allows the UE to attach at EPS 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 [5].
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.
EU-Alert: Public Warning System that delivers Warning Notifications provided by Warning Notification Providers
using the same AS mechanisms as defined for CMAS.
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.
HNB Name: The Home eNodeB Name is a broadcast string in free text format that provides a human readable name for
the Home eNodeB CSG identity and any broadcasted PLMN identity.
HSDN cell: A cell that has higher priority than other cells for cell reselection for HSDN capable UE in a High-mobility
state.
ETSI

---------------------- Page: 9 ----------------------
3GPP TS
...