ETSI TR 137 985 V16.0.0 (2020-07)

LTE; 5G; Overall description of Radio Access Network (RAN) aspects for Vehicle-to-everything (V2X) based on LTE and NR (3GPP TR 37.985 version 16.0.0 Release 16)

DTR/TSGR-0137985vg00

General Information

• Status: Not Published
• Technical Committee: 3GPP RAN 1 - Radio layer 1 specification
• Current Stage: 12 - Completion
• Completion Date: 29-Jul-2020

Standards Content (Sample)

ETSI TR 137 985 V16.0.0 (2020-07)






TECHNICAL REPORT
LTE;
5G;
Overall description of Radio Access Network (RAN)
aspects for Vehicle-to-everything (V2X) based on LTE and NR
(3GPP TR 37.985 version 16.0.0 Release 16)

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3GPP TR 37.985 version 16.0.0 Release 16 1 ETSI TR 137 985 V16.0.0 (2020-07)



Reference
DTR/TSGR-0137985vg00
Keywords
5G,LTE
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3GPP TR 37.985 version 16.0.0 Release 16 2 ETSI TR 137 985 V16.0.0 (2020-07)
Intellectual Property Rights
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Legal Notice
This Technical Report (TR) 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 "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

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3GPP TR 37.985 version 16.0.0 Release 16 3 ETSI TR 137 985 V16.0.0 (2020-07)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
Introduction . 6
1 Scope . 7
2 References . 7
3 Definitions of terms, symbols and abbreviations . 8
3.1 Terms . 8
3.2 Symbols . 8
3.3 Abbreviations . 8
4 Services and requirements . 9
5 LTE V2X . 10
5.1 V2X sidelink physical layer . 10
5.1.1 Physical sidelink channels and signals. 10
5.1.2 Sidelink synchronization . 11
5.1.2.1 Synchronization references and priorities . 11
5.1.2.2 SLSS . 11
5.1.2.2.1 SLSSID . 12
5.1.3 Multi-carrier operation and carrier aggregation . 12
5.2 V2X sidelink resource allocation . 13
5.2.1 Resource pools . 13
5.2.2 Resource allocation modes . 14
5.2.2.1 Resource allocation mode 3 . 14
5.2.2.2 Resource allocation mode 4 . 15
5.2.2.2.1 Zones . 16
5.2.2.3 Modes 3 and 4 resource pool sharing . 17
5.3 Sidelink congestion control . 17
5.4 V2X sidelink higher-layer protocols . 17
5.4.1 General . 17
5.4.2 Resource pool configuration . 18
5.4.3 Measurement and reporting . 18
5.4.4 Mobility management . 18
5.4.5 Assistance information for SL SPS configuration . 18
5.4.6 Transmission carrier selection . 18
5.4.7 SL packet duplication . 18
5.4.8 Coordination between UL and V2X SL transmission . 19
5.4.9 Multi-PLMN operation . 19
5.5 V2X via the Uu interface . 19
5.6 Network aspects . 19
5.6.1 V2X service authorization . 19
5.6.2 Sidelink AMBR . 19
6 NR V2X. 20
6.1 Sidelink unicast, groupcast, and broadcast . 20
6.2 V2X sidelink physical layer . 20
6.2.1 Physical sidelink channels and signals. 20
6.2.2 Sidelink synchronization . 21
6.2.2.1 Synchronization references and priorities . 21
6.2.2.2 S-SSB and SLSS . 22
6.2.2.2.1 SLSSID . 22
6.2.3 Sidelink CSI . 23
6.2.4 Sidelink HARQ . 23
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6.2.5 In-device coexistence between LTE-V2X and NR-V2X sidelinks . 23
6.3 V2X sidelink resource allocation . 24
6.3.1 Sidelink bandwidth parts and resource pools . 24
6.3.1.1 Sidelink bandwidth parts . 24
6.3.1.2 Resource pools . 24
6.3.2 Resource allocation modes . 24
6.3.2.1 Mode 1 . 24
6.3.2.2 Mode 2 . 25
6.4 Sidelink congestion control . 27
6.5 V2X sidelink higher-layer protocols . 27
6.5.1 General . 27
6.5.2 Measurement and reporting related to NR sidelink communication . 28
6.5.3 Mobility management for NR SL transmission/reception . 29
6.5.4 Assistance information and SL configured grant configuration . 29
6.5.5 Coordination between UL and NR SL transmission . 29
6.5.6 QoS mechanism . 29
6.5.7 Sidelink RRC . 30
6.6 V2X via the Uu interface . 30
6.7 Network aspects . 30
6.7.1 V2X service authorization . 30
6.7.2 Alternative QoS Profiles . 30
7 Multi-RAT V2X . 30
7.1 Cross-RAT operation . 30
7.2 MR-DC . 31
8 Transmission profiles . 33
9 Pedestrian UE . 33
10 Roadside unit . 34
Annex (informative): Change history . 35
History . 36

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3GPP TR 37.985 version 16.0.0 Release 16 5 ETSI TR 137 985 V16.0.0 (2020-07)
Foreword
This Technical Report 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.
In the present document, certain modal verbs have the following meanings:
shall indicates a mandatory requirement to do something
shall not indicates an interdiction (prohibition) to do something
NOTE 1: The constructions "shall" and "shall not" are confined to the context of normative provisions, and do not
appear in Technical Reports.
NOTE 2: The constructions "must" and "must not" are not used as substitutes for "shall" and "shall not". Their use
is avoided insofar as possible, and they are not used in a normative context except in a direct citation from
an external, referenced, non-3GPP document, or so as to maintain continuity of style when extending or
modifying the provisions of such a referenced document.
should indicates a recommendation to do something
should not indicates a recommendation not to do something
may indicates permission to do something
need not indicates permission not to do something
NOTE 3: The construction "may not" is ambiguous and is not used in normative elements. The unambiguous
constructions "might not" or "shall not" are used instead, depending upon the meaning intended.
can indicates that something is possible
cannot indicates that something is impossible
NOTE 4: The constructions "can" and "cannot" shall not to be used as substitutes for "may" and "need not".
will indicates that something is certain or expected to happen as a result of action taken by an agency
the behaviour of which is outside the scope of the present document
will not indicates that something is certain or expected not to happen as a result of action taken by an
agency the behaviour of which is outside the scope of the present document
might indicates a likelihood that something will happen as a result of action taken by some agency the
behaviour of which is outside the scope of the present document
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might not indicates a likelihood that something will not happen as a result of action taken by some agency
the behaviour of which is outside the scope of the present document
In addition:
is (or any other verb in the indicative mood) indicates a statement of fact
is not (or any other negative verb in the indicative mood) indicates a statement of fact
NOTE 5: The constructions "is" and "is not" do not indicate requirements.
Introduction
The 3GPP platform was first expanded to the automotive industry by the introduction of support for V2V and V2X
services in Release 14. This support forms Phase 1 of 3GPP's ongoing project relating to V2X, and was intended to
support a set of requirements sufficient for basic road safety services. Vehicles containing UEs with these features can
use the uplink, downlink and sidelink to exchange information on their own status, such as position, speed, and heading
with other nearby vehicles, infrastructure nodes, and pedestrians. Phase 2 of the V2X project was standardised in
Release 15, and adds a number of new features to the sidelink intended to enhance efficiency and exploit developments
in UE and network designs. These enhancements include sidelink carrier aggregation, higher-order modulation, and
reduced latency.
Phase 3 of V2X, in Release 16, adds support to NR (and also 5GC, not addressed in this TR) for advanced V2X use
cases, and includes introduction of the NR sidelink. The use-cases are broadly grouped to enable vehicular platooning,
exchange of extended sensor information, advanced driving, and remote driving. Phase 3 also allows either RAT's
sidelink to be operated under control of the other RAT's Uu interface, as well as permitting connection to EPC or 5GC,
to enable usage in the main MR-DC deployment scenarios.
In the following clauses, LTE-V2X is described first, then NR-V2X, and finally certain aspects which have a degree of
commonality to both RATs.
Although this TR deals with RAN aspects, note that the core network architectures also have many adaptations to
support V2X in both EPC and 5GC. These are referred to only as needed for other explanations in this TR, and details
can be found in the relevant specifications.
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1 Scope
The present document provides an overall description of the features introduced by 3GPP to LTE and NR in support of
V2X services, starting from Rel-14. The purpose of this TR is to give an overview across the RAN specifications of
how the features have been designed, and how they operate together. This document addresses LTE V2X and NR V2X
via both sidelink, i.e. the PC5 interfaces, and via the cellular uplink/downlink, i.e. the Uu interfaces. It covers V2V,
V2I/N, and V2P, as well as the eNB/gNB, UE, and RSU nodes. The intention is to provide descriptions at
approximately the Stage 2 level of detail, and thus references are provided to RAN specifications for the reader to
obtain precise details.
The document is a 'living' document, i.e. it is permanently updated and presented to TSG-RAN meetings.
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 TR 36.885: "Study on LTE-based V2X Services".
[3] ETSI EN 302 637-2: "Specification of Cooperative Awareness Basic Service".
[4] SAE J2735: "Dedicated Short Range Communications (DSRC) Message Set Dictionary".
[5] ETSI EN 302 637-3 "Specifications of Decentralized Environmental Notification Basic Service".
[6] 3GPP TS 22.185: "Service requirements for V2X services".
[7] 3GPP TS 22.186: "Enhancement of 3GPP support for V2X scenarios".
[8] 3GPP TS 36.211: "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and
modulation".
[9] 3GPP TS 36.212: "Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and
channel coding".
[10] 3GPP TS 36.331: "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource
Control (RRC)".
[11] 3GPP TS 36.101: "Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE)
radio transmission and reception".
[12] 3GPP TS 36.214: "Evolved Universal Terrestrial Radio Access (E-UTRA); Measurements".
[13] 3GPP TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal
Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2".
[14] 3GPP TS 36.321: "Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access
Control (MAC)".
[15] 3GPP TS 36.323: "Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data
Convergence Protocol (PDCP)".
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[16] 3GPP TS 38.211: "NR; Physical channels and modulation".
[17] 3GPP TS 38.331: "NR; Radio Resource Control (RRC) protocol specification".
[18] 3GPP TS 38.213: "NR; Physical layer procedures for control".
[19] 3GPP TS 37.340: "Evolved Universal Terrestrial Radio Access (E-UTRA) and NR; Multi-
connectivity; Stage 2".
[20] 3GPP TS 38.300: "NR; NR and NG-RAN Overall Description; Stage 2".
[21] 3GPP TS 38.321: "NR; Medium Access Control (MAC) protocol specification".
3 Definitions of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in TR 21.905 [1] and the following apply. A term defined in
the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].
example: text used to clarify abstract rules by applying them literally.
3.2 Symbols
For the purposes of the present document, the following symbols apply:


3.3 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].
Where the same abbreviation is used for LTE V2X and NR V2X, which is meant can be derived from the clause within
which it appears, unless otherwise stated.
5GC Fifth Generation core network
AGC Automatic gain control
AMBR Aggregate maximum bit rate
BSM Basic safety message
BWP Bandwidth part
CA Carrier aggregation
CAM Cooperative awareness message
CBR Channel busy ratio
CR Channel usage ratio
DENM Decentralized environmental notification message
DMRS Demodulation reference signal
EPC Evolved packet core
MBSFN Multicast-broadcast single-frequency network
MNO Mobile network operator
PPPP ProSe per-packet priority
PPPR ProSe per-packet reliability
PSBCH Physical sidelink broadcast channel
PSCCH Physical sidelink control channel
PSSCH Physical sidelink shared channel
PSSS, S-PSS Primary sidelink synchronization signal (LTE), sidelink primary synchronization signal (NR)
PT-RS Phase-tracking reference signal
P-UE Pedestrian UE
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RSU Roadside unit
SA Scheduling assignment
SCI Sidelink control information
SC-PTM Single-cell point-to-multipoint
SL-BCH Sidelink broadcast channel
SLSS Sidelink synchronization signal
S-RSSI Sidelink received signal strength indicator
S-SSB Sidelink synchronization signal block
SSSS, S-SSS Secondary sidelink synchronization signal (LTE), sidelink secondary synchronization signal (NR)
V2I Vehicle-to-infrastructure
V2P Vehicle-to-pedestrian
V2V Vehicle-to-vehicle
V2X Vehicle-to-everything

4 Services and requirements
LTE-V2X is designed with BSM, CAM, and DENM particularly in mind. BSMs and CAMs have the characteristic of
generating periodic messages at intervals, whereas DENMs are event-triggered. As an illustration of the different
message types, in TR 36.885 [2], BSM/CAM were modelled, for evaluation purposes, as periodically occurring sets of
one 300-byte message followed by four 190-byte messages. These types of message regularly broadcast information
such as the vehicle's heading, speed, latitude/longitude, etc. ETSI EN 302 637-2 [3], SAE J2735 [4]. In TR 36.885 [2],
DENMs were modelled, for evaluation purposes, as Poisson distributed initiations of six 800-byte messages spaced by
100 ms. DENMs can contain various different messages depending on the cause for their transmission, such as
imminent collision, sudden braking, or detection of a traffic jam, amongst others ETSI EN 302 63
...