SIST EN 302 663 V1.3.1:2020

Final draft ETSI EN 302 663 V1.3.1 (2019-10)

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
ITS-G5 Access layer specification for Intelligent Transport
Systems operating in the 5 GHz frequency band

2 Final draft ETSI EN 302 663 V1.3.1 (2019-10)

Reference
REN/ITS-0040191
Keywords
ITS, layer 1, layer 2, MAC, profile, radio

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 2019.
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
3 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 7
3.1 Terms . 7
3.2 Symbols . 8
3.3 Abbreviations . 8
4 Access layer requirements . 9
4.1 Introduction . 9
4.2 Physical layer . 10
4.3 Data link layer . 11
4.3.1 Introduction. 11
4.3.2 Decentralized congestion control . 11
4.3.3 Logical link control . 11
4.3.4 Medium access control . 12
4.4 CEN DSRC and HDR DSRC protection . 12
5 ITS-G5 radio tests . 12
5.1 Radio tests defined in ETSI EN 302 571 . 12
5.2 Additional radio tests. 12
5.2.1 Dynamic receiver sensitivity. 12
Annex A (normative): Channel models for testing dynamic sensitivity values . 14
Annex B (informative): Data and management service . 16
B.1 Access layer data service . 16
B.2 Access layer management service . 16
Annex C (informative): Introduction to IEEE 802.11-2016. 17
C.1 Introduction . 17
C.2 Network topology . 18
C.3 Physical layer . 18
C.4 Medium access control . 19
C.4.1 Introduction . 19
C.4.2 Backoff procedure . 20
C.4.3 Medium access control . 20
C.4.4 EDCA parameters, AC and UP . 21
C.5 Implications of the dot11OCBActivated set to true . 23
Annex D (informative): Change History . 24
History . 25

ETSI
4 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
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.
Foreword
This final draft European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport
Systems (ITS), and is now submitted for the Vote phase of the ETSI standards EN Approval Procedure.

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

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
5 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
Introduction
The present document outlines the two lowest layers - physical layer and data link layer - in the protocol stack for
supporting vehicle-to-vehicle communications in an ad hoc network to be used at the 5,9 GHz frequency band allocated
in Europe in compliance with Commission Decision 2008/671/EC [i.1], ECC/DEC/(08)01 [i.2] and
ECC/REC/(08)01 [i.3]. The two lowest layers are termed access layer according to ETSI EN 302 665 [i.4] in the present
document and the technology specified for the access layer is collectively called ITS-G5. The ITS-G5 access layer
technology is using already existing standards for communications. The data link layer is divided into two sublayers;
medium access control and logical link control. The physical layer and the medium access control layer are covered in
IEEE 802.11-2016 [1]. The logical link control is based on the IEEE/ISO/IEC 8802-2-1998 [2]. The ITS-G5 standard
also adds features for Decentralized Congestion Control (DCC) methods ETSI TS 102 687 [3] to control the network
load.
By setting the Management Information Base (MIB) parameter dot11OCBActivated to true in
IEEE 802.11-2016 [1] a new capability is introduced namely the possibility to communicate outside the context of a
Basic Service Set (BSS), which is the smallest building block of an 802.11 network. Communication outside the BSS
implies that neither authentication/association procedures nor security mechanisms are supported. Further, no access
point functionality is present. The disable of these features also affects other built-in features of IEEE 802.11-2016 [1].
The requirement that nodes should share a common clock is no longer valid while dot11OCBActivated is true.
Further, scanning of available frequency channels for joining a BSS is also disabled implying that communication
outside the context of the BSS requires that a node is configured for a predetermined frequency channel where more
information about other available frequency channels can be obtained.

ETSI
6 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
1 Scope
The present document defines the two lowest layers, physical layer and the data link layer, grouped into the access layer
of the ITS station reference architecture ETSI EN 302 665 [i.4].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
TM
[1] IEEE 802.11 -2016: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
[2] IEEE/ISO/IEC 8802-2-1998: "Information technology -- Telecommunications and information
exchange between systems -- Local and metropolitan area networks -- Specific requirements --
Part 2: Logical Link Control".
[3] ETSI TS 102 687 (V1.2.1): "Intelligent Transport Systems (ITS); Decentralized Congestion
Control Mechanisms for Intelligent Transport Systems operating in the 5 GHz range; Access layer
part".
TM
-2014: "IEEE Standard for Local and Metropolitan Area Networks: Overview and
[4] IEEE 802
Architecture".
[5] ETSI EN 302 571 (V2.1.1): "Intelligent Transport Systems (ITS); Radiocommunications
equipment operating in the 5 855 MHz to 5 925 MHz frequency band; Harmonised Standard
covering the essential requirements of article 3.2 of Directive 2014/53/EU".
[6] ETSI TS 102 792 (V1.2.1): "Intelligent Transport Systems (ITS); Mitigation techniques to avoid
interference between European CEN Dedicated Short Range Communication (CEN DSRC)
equipment and Intelligent Transport Systems (ITS) operating in the 5 GHz frequency range".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
ETSI
7 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
[i.1] Commission Decision 2008/671/EC of 5 August 2008 on the harmonised use of radio spectrum in
the 5 875-5 905 MHz frequency band for safety-related applications of Intelligent Transport
Systems (ITS).
[i.2] ECC/DEC/(08)01: "ECC Decision (08)01 on the harmonised use of the band 5875-5925 MHz for
Intelligent Transport Systems (ITS)".
[i.3] ECC/REC/(08)01: "ECC Recommendation (08)01 on the use of the band 5855-5875 MHz for
Intelligent Transport Systems (ITS)".
[i.4] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture".
TM
[i.5] IEEE 802.11p -2010: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments".
TM
[i.6] IEEE 802.11 -2012: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
TM
[i.7] IEEE 802.11a -1999: "IEEE Standard for Telecommunications and Information Exchange
Between Systems - LAN/MAN Specific Requirements - Part 11: Wireless Medium Access Control
(MAC) and physical layer (PHY) specifications: High Speed Physical Layer in the 5 GHz band".
TM
[i.8] IEEE 802.11e -2005: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications - Amendment: Medium Access Method (MAC) Quality of
Service Enhancements".
[i.9] ANSI/IEEE 802.1D-1998: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks - Common
specifications - Part 3: Media Access Control (MAC) Bridges".
[i.10] IEEE Registration Authority.
NOTE: Available at https://standards.ieee.org/content/ieee-standards/en/products-services/regauth/index.html.
[i.11] List of assigned EtherTypes at the IEEE Registration Authority.
NOTE: Available at http://standards-oui.ieee.org/ethertype/eth.txt.
[i.12] ETSI EN 302 636-4-1 (V1.3.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
[i.13] ETSI TS 103 175 (V1.1.1): "Intelligent Transport Systems (ITS); Cross Layer DCC Management
Entity for operation in the ITS G5A and ITS G5B medium".
TM
[i.14] IEEE 802.11 -2007: "IEEE Standard for Information Technology - Telecommunications and
Information Exchange Between Systems - Local and Metropolitan Area Networks - Specific
Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
ethertype: identifier to the network protocol above the data link layer
ETSI
8 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
ITS-G5 access layer: access layer technology to be used in frequency bands dedicated for European Intelligent
Transport Systems (ITS)
3.2 Symbols
For the purposes of the present document, the following symbols apply:
aCWmax Maximum value of Contention Window
aCWmin Minimum value of Contention Window
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
aSIFSTime Short InterFrame Space defined by the physical layer
aSlotTime A slot time defined by the physical layer
CW Contention Window
CW Maximum value of Contention Window
max
CW Minimum value of Contention Window
min
T period of time the channel is busy
busy
T period of time
CBR
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Access Category
AC_BE Access Category Best Effort
AC_BK Access Category Background
AC_VI Access Category Video
AC_VO Access Category Voice
ACK Acknowledgment
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
AP Access Point
BE Best Effort
BK Background
BPSK Binary Phase Shift Keying
BSS Basic Service Set
BSSID Basic Service Set Identification
CBR Channel Busy Ratio
CEN European Committee for Standardization
CSMA/CA Carrier Sense Multiple Access with Collision Avoidance
CW Contention Window
DCC Decentralized Congestion Control
DCF Distributed Coordination Function
DIFS Distributed InterFrame Space
DSRC Dedicated Short-Range Communication
DUT Device Under Test
ECC Electronic Communication Committee
EDCA Enhanced Distribution Coordination Access
EE Excellent Effort
EN European Norm
EPD EtherType Protocol Discrimination
GPS Global Positioning System
HDR High Data Rate
IBSS Independent Basic Service Set
IEEE Institute of Electrical and Electronics Engineers
ITS Intelligent Transport Systems
LLC Logical Link Control
LOS Line-Of-Sight
MAC Medium Access Control
ETSI
9 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
MCS Modulation and Coding Scheme
MIB Management Information Base
MPDU MAC Protocol Data Unit
NC Network Control
NLOS Non Line-Of-Sight
OFDM Orthogonal Frequency Division Multiplexing
PDU Protocol Data Unit
PER Packet Error Rate
PHY Physical layer
PLCP Physical Layer Convergence Protocol
PPDU PLCP Protocol Data Unit
PSDU PLCP Service Data Unit
QAM Quadrature Amplitude Modulation
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
SNAP SubNetwork Access Protocol
TDL Tapped Delay Line
TS Technical Specification
TX Transmitter
UP User Priority
VI Video
VO Voice
WLAN Wireless Local Area Network
4 Access layer requirements
4.1 Introduction
The access layer bundles the data link layer and the physical layer and it is situated at the bottom of the ITS protocol
stack, see Figure 1. The ITS station reference architecture and the definition of an ITS station are outlined in ETSI
EN 302 665 [i.4].
Applications
ITS applications
Facilities
Data link
Networking &
Protocols
Transport
Physical
Access
Figure 1: ITS station reference architecture
The access layer technology consists of IEEE 802.11-2016 [1], IEEE/ISO/IEC 8802-2-1998 [2], IEEE 802-2014 [4] and
ETSI TS 102 687 [3], see Figure 2. An introduction to IEEE 802.11-2016 [1] with the MIB parameter
dot11OCBActivated set to true is provided in informative Annex C. Interfaces between access layer and
management entity and access layer and networking & transport layer are found in Annex B.
ETSI
Management
Security
10 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
IEEE/ISO/IEC 8802-2 with SNAP
Data link
IEEE 802.11
Access
Physical IEEE 802.11
Figure 2: Protocols comprising the access layer
4.2 Physical layer
The physical layer of ITS-G5 shall be the orthogonal frequency division multiplexing (OFDM) "half-clocked" operation
using 10 MHz frequency channels as outlined in IEEE 802.11-2016 [1], clause 17. Mandatory transfer rates are
3 Mbit/s, 6 Mbit/sand 12 Mbit/s.
The limits for static receiver sensitivity shall be as outlined in Table 1.
Table 1: Static receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
3 BPSK 1/2 -91
4,5 BPSK 3/4 -90
6 QPSK 1/2 -88
9 QPSK 3/4 -86
12 16-QAM 1/2 -83
18 16-QAM 3/4 -79
24 64-QAM 2/3 -75
27 64-QAM 3/4 -74
The limits for dynamic receiver sensitivity (i.e. the receiver sensitivity in the presence of interference) shall be as
outlined in Table 2.
Table 2: Dynamic receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
6 QPSK 1/2 -85
The limits for receiver adjacent channel rejection and alternate adjacent channel rejection shall be as outlined in
Table 3.
Table 3: Limits for receiver adjacent channel rejection and
alternate adjacent channel rejection
Alternate adjacent
Transfer rate Adjacent channel
Modulation Coding rate channel rejection
(Mbit/s) rejection (dB)
(dB)
3 BPSK 1/2 28 42
4,5 BPSK 3/4 27 41
6 QPSK 1/2 25 39
9 QPSK 3/4 23 37
12 16-QAM 1/2 20 34
18 16-QAM 3/4 16 30
24 64-QAM 2/3 12 26
27 64-QAM 3/4 11 25
ETSI
ETSI
TS 102 687
11 Final draft ETSI EN 302 663 V1.3.1 (2019-10)
4.3 Data link layer
4.3.1 Introduction
The data link layer consists of two sublayers - logical link control (LLC) and medium access control (MAC) - where the
former provides means for distinguishing between different network layer protocols and the latter is responsible for
scheduling transmissions to minimize interference between ITS stations. Decentralized Congestion Control (DCC) is a
management entity controlling the network load by for example regulating the number of transmission opportunities the
ITS station has based on the current load. Thus DCC is not a protocol to achieve interoperability but merely an
algorithm controlling that a single ITS station does not consume all resources on the channel. Figure 3 illustrates the
different sublayers and protocols.
IEEE/ISO/IEC 8802-2 with SNAP
LLC
Data link
MAC IEEE 802.11
Figure 3: Protocols and DCC management entity comprising the data link layer
4.3.2 Decentralized congestion control
ETSI TS 102 687 [3] shall be fulfilled and the selected DCC algorithm shall respect the limits provided below.
The Channel Busy Ratio (CBR) is used for determining the transmission behaviour. CBR is an estimate of how much a
single channel is used based on listening on surrounding radio transmitters. The determination of CBR for the equipment
shall be as performed according to Equation 1. Any other equivalent mechanism may be used providing a CBR with a
deviation of ±3 %.
CBR , (1)
T is the period of time in milliseconds when the strength of received ITS-G5 signals over a period of T
busy CBR
exceeds -85 dBm. T is equal to 100 milliseconds. T is the duration of a transmission by the equipment and
...

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
ITS-G5 Access layer specification for Intelligent Transport
Systems operating in the 5 GHz frequency band

2 ETSI EN 302 663 V1.3.1 (2020-01)

Reference
REN/ITS-0040191
Keywords
ITS, layer 1, layer 2, MAC, profile, radio

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
3 ETSI EN 302 663 V1.3.1 (2020-01)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 7
3.1 Terms . 7
3.2 Symbols . 8
3.3 Abbreviations . 8
4 Access layer requirements . 9
4.1 Introduction . 9
4.2 Physical layer . 10
4.3 Data link layer . 11
4.3.1 Introduction. 11
4.3.2 Decentralized congestion control . 11
4.3.3 Logical link control . 11
4.3.4 Medium access control . 12
4.4 CEN DSRC and HDR DSRC protection . 12
5 ITS-G5 radio tests . 12
5.1 Radio tests defined in ETSI EN 302 571 . 12
5.2 Additional radio tests. 12
5.2.1 Dynamic receiver sensitivity. 12
Annex A (normative): Channel models for testing dynamic sensitivity values . 14
Annex B (informative): Data and management service . 16
B.1 Access layer data service . 16
B.2 Access layer management service . 16
Annex C (informative): Introduction to IEEE 802.11-2016. 17
C.1 Introduction . 17
C.2 Network topology . 18
C.3 Physical layer . 18
C.4 Medium access control . 19
C.4.1 Introduction . 19
C.4.2 Backoff procedure . 20
C.4.3 Medium access control . 20
C.4.4 EDCA parameters, AC and UP . 21
C.5 Implications of the dot11OCBActivated set to true . 23
Annex D (informative): Change History . 24
History . 25

ETSI
4 ETSI EN 302 663 V1.3.1 (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.
Foreword
This European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport Systems (ITS).

National transposition dates
Date of adoption of this EN: 23 December 2019
Date of latest announcement of this EN (doa): 31 March 2020
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 September 2020
Date of withdrawal of any conflicting National Standard (dow): 30 September 2020

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
5 ETSI EN 302 663 V1.3.1 (2020-01)
Introduction
The present document outlines the two lowest layers - physical layer and data link layer - in the protocol stack for
supporting vehicle-to-vehicle communications in an ad hoc network to be used at the 5,9 GHz frequency band allocated
in Europe in compliance with Commission Decision 2008/671/EC [i.1], ECC/DEC/(08)01 [i.2] and
ECC/REC/(08)01 [i.3]. The two lowest layers are termed access layer according to ETSI EN 302 665 [i.4] in the present
document and the technology specified for the access layer is collectively called ITS-G5. The ITS-G5 access layer
technology is using already existing standards for communications. The data link layer is divided into two sublayers;
medium access control and logical link control. The physical layer and the medium access control layer are covered in
IEEE 802.11-2016 [1]. The logical link control is based on the IEEE/ISO/IEC 8802-2-1998 [2]. The ITS-G5 standard
also adds features for Decentralized Congestion Control (DCC) methods ETSI TS 102 687 [3] to control the network
load.
By setting the Management Information Base (MIB) parameter dot11OCBActivated to true in
IEEE 802.11-2016 [1] a new capability is introduced namely the possibility to communicate outside the context of a
Basic Service Set (BSS), which is the smallest building block of an 802.11 network. Communication outside the BSS
implies that neither authentication/association procedures nor security mechanisms are supported. Further, no access
point functionality is present. The disable of these features also affects other built-in features of IEEE 802.11-2016 [1].
The requirement that nodes should share a common clock is no longer valid while dot11OCBActivated is true.
Further, scanning of available frequency channels for joining a BSS is also disabled implying that communication
outside the context of the BSS requires that a node is configured for a predetermined frequency channel where more
information about other available frequency channels can be obtained.

ETSI
6 ETSI EN 302 663 V1.3.1 (2020-01)
1 Scope
The present document defines the two lowest layers, physical layer and the data link layer, grouped into the access layer
of the ITS station reference architecture ETSI EN 302 665 [i.4].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
TM
[1] IEEE 802.11 -2016: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
[2] IEEE/ISO/IEC 8802-2-1998: "Information technology -- Telecommunications and information
exchange between systems -- Local and metropolitan area networks -- Specific requirements --
Part 2: Logical Link Control".
[3] ETSI TS 102 687 (V1.2.1): "Intelligent Transport Systems (ITS); Decentralized Congestion
Control Mechanisms for Intelligent Transport Systems operating in the 5 GHz range; Access layer
part".
TM
-2014: "IEEE Standard for Local and Metropolitan Area Networks: Overview and
[4] IEEE 802
Architecture".
[5] ETSI EN 302 571 (V2.1.1): "Intelligent Transport Systems (ITS); Radiocommunications
equipment operating in the 5 855 MHz to 5 925 MHz frequency band; Harmonised Standard
covering the essential requirements of article 3.2 of Directive 2014/53/EU".
[6] ETSI TS 102 792 (V1.2.1): "Intelligent Transport Systems (ITS); Mitigation techniques to avoid
interference between European CEN Dedicated Short Range Communication (CEN DSRC)
equipment and Intelligent Transport Systems (ITS) operating in the 5 GHz frequency range".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
ETSI
7 ETSI EN 302 663 V1.3.1 (2020-01)
[i.1] Commission Decision 2008/671/EC of 5 August 2008 on the harmonised use of radio spectrum in
the 5 875-5 905 MHz frequency band for safety-related applications of Intelligent Transport
Systems (ITS).
[i.2] ECC/DEC/(08)01: "ECC Decision (08)01 on the harmonised use of the band 5875-5925 MHz for
Intelligent Transport Systems (ITS)".
[i.3] ECC/REC/(08)01: "ECC Recommendation (08)01 on the use of the band 5855-5875 MHz for
Intelligent Transport Systems (ITS)".
[i.4] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture".
TM
[i.5] IEEE 802.11p -2010: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments".
TM
[i.6] IEEE 802.11 -2012: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
TM
[i.7] IEEE 802.11a -1999: "IEEE Standard for Telecommunications and Information Exchange
Between Systems - LAN/MAN Specific Requirements - Part 11: Wireless Medium Access Control
(MAC) and physical layer (PHY) specifications: High Speed Physical Layer in the 5 GHz band".
TM
[i.8] IEEE 802.11e -2005: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications - Amendment: Medium Access Method (MAC) Quality of
Service Enhancements".
[i.9] ANSI/IEEE 802.1D-1998: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks - Common
specifications - Part 3: Media Access Control (MAC) Bridges".
[i.10] IEEE Registration Authority.
NOTE: Available at https://standards.ieee.org/content/ieee-standards/en/products-services/regauth/index.html.
[i.11] List of assigned EtherTypes at the IEEE Registration Authority.
NOTE: Available at http://standards-oui.ieee.org/ethertype/eth.txt.
[i.12] ETSI EN 302 636-4-1 (V1.3.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
[i.13] ETSI TS 103 175 (V1.1.1): "Intelligent Transport Systems (ITS); Cross Layer DCC Management
Entity for operation in the ITS G5A and ITS G5B medium".
TM
[i.14] IEEE 802.11 -2007: "IEEE Standard for Information Technology - Telecommunications and
Information Exchange Between Systems - Local and Metropolitan Area Networks - Specific
Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
ethertype: identifier to the network protocol above the data link layer
ETSI
8 ETSI EN 302 663 V1.3.1 (2020-01)
ITS-G5 access layer: access layer technology to be used in frequency bands dedicated for European Intelligent
Transport Systems (ITS)
3.2 Symbols
For the purposes of the present document, the following symbols apply:
aCWmax Maximum value of Contention Window
aCWmin Minimum value of Contention Window
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
aSIFSTime Short InterFrame Space defined by the physical layer
aSlotTime A slot time defined by the physical layer
CW Contention Window
CW Maximum value of Contention Window
max
CW Minimum value of Contention Window
min
T period of time the channel is busy
busy
T period of time
CBR
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Access Category
AC_BE Access Category Best Effort
AC_BK Access Category Background
AC_VI Access Category Video
AC_VO Access Category Voice
ACK Acknowledgment
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
AP Access Point
BE Best Effort
BK Background
BPSK Binary Phase Shift Keying
BSS Basic Service Set
BSSID Basic Service Set Identification
CBR Channel Busy Ratio
CEN European Committee for Standardization
CSMA/CA Carrier Sense Multiple Access with Collision Avoidance
CW Contention Window
DCC Decentralized Congestion Control
DCF Distributed Coordination Function
DIFS Distributed InterFrame Space
DSRC Dedicated Short-Range Communication
DUT Device Under Test
ECC Electronic Communication Committee
EDCA Enhanced Distribution Coordination Access
EE Excellent Effort
EN European Norm
EPD EtherType Protocol Discrimination
GPS Global Positioning System
HalfBT Half Bathtub
HDR High Data Rate
IBSS Independent Basic Service Set
IEEE Institute of Electrical and Electronics Engineers
ITS Intelligent Transport Systems
LLC Logical Link Control
LOS Line-Of-Sight
ETSI
9 ETSI EN 302 663 V1.3.1 (2020-01)
MAC Medium Access Control
MCS Modulation and Coding Scheme
MIB Management Information Base
MPDU MAC Protocol Data Unit
NC Network Control
NLOS Non Line-Of-Sight
OFDM Orthogonal Frequency Division Multiplexing
PDU Protocol Data Unit
PER Packet Error Rate
PHY Physical layer
PLCP Physical Layer Convergence Protocol
PPDU PLCP Protocol Data Unit
PSDU PLCP Service Data Unit
QAM Quadrature Amplitude Modulation
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
SNAP SubNetwork Access Protocol
TDL Tapped Delay Line
TS Technical Specification
TX Transmitter
UP User Priority
VI Video
VO Voice
WLAN Wireless Local Area Network
4 Access layer requirements
4.1 Introduction
The access layer bundles the data link layer and the physical layer and it is situated at the bottom of the ITS protocol
stack, see Figure 1. The ITS station reference architecture and the definition of an ITS station are outlined in ETSI
EN 302 665 [i.4].
Applications
ITS applications
Facilities
Data link
Networking &
Protocols
Transport
Physical
Access
Figure 1: ITS station reference architecture
The access layer technology consists of IEEE 802.11-2016 [1], IEEE/ISO/IEC 8802-2-1998 [2], IEEE 802-2014 [4] and
ETSI TS 102 687 [3], see Figure 2. An introduction to IEEE 802.11-2016 [1] with the MIB parameter
dot11OCBActivated set to true is provided in informative Annex C. Interfaces between access layer and
management entity and access layer and networking & transport layer are found in Annex B.
ETSI
Management
Security
10 ETSI EN 302 663 V1.3.1 (2020-01)
IEEE/ISO/IEC 8802-2 with SNAP
Data link
IEEE 802.11
Access
Physical IEEE 802.11
Figure 2: Protocols comprising the access layer
4.2 Physical layer
The physical layer of ITS-G5 shall be the orthogonal frequency division multiplexing (OFDM) "half-clocked" operation
using 10 MHz frequency channels as outlined in IEEE 802.11-2016 [1], clause 17. Mandatory transfer rates are
3 Mbit/s, 6 Mbit/sand 12 Mbit/s.
The limits for static receiver sensitivity shall be as outlined in Table 1.
Table 1: Static receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
3 BPSK 1/2 -91
4,5 BPSK 3/4 -90
6 QPSK 1/2 -88
9 QPSK 3/4 -86
12 16-QAM 1/2 -83
18 16-QAM 3/4 -79
24 64-QAM 2/3 -75
27 64-QAM 3/4 -74
The limits for dynamic receiver sensitivity (i.e. the receiver sensitivity in the presence of interference) shall be as
outlined in Table 2.
Table 2: Dynamic receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
6 QPSK 1/2 -85
The limits for receiver adjacent channel rejection and alternate adjacent channel rejection shall be as outlined in
Table 3.
Table 3: Limits for receiver adjacent channel rejection and
alternate adjacent channel rejection
Alternate adjacent
Transfer rate Adjacent channel
Modulation Coding rate channel rejection
(Mbit/s) rejection (dB)
(dB)
3 BPSK 1/2 28 42
4,5 BPSK 3/4 27 41
6 QPSK 1/2 25 39
9 QPSK 3/4 23 37
12 16-QAM 1/2 20 34
18 16-QAM 3/4 16 30
24 64-QAM 2/3 12 26
27 64-QAM 3/4 11 25
ETSI
ETSI
TS 102 687
11 ETSI EN 302 663 V1.3.1 (2020-01)
4.3 Data link layer
4.3.1 Introduction
The data link layer consists of two sublayers - logical link control (LLC) and medium access control (MAC) - where the
former provides means for distinguishing between different network layer protocols and the latter is responsible for
scheduling transmissions to minimize interference between ITS stations. Decentralized Congestion Control (DCC) is a
management entity controlling the network load by for example regulating the number of transmission opportunities the
ITS station has based on the current load. Thus DCC is not a protocol to achieve interoperability but merely an
algorithm controlling that a single ITS station does not consume all resources on the channel. Figure 3 illustrates the
different sublayers and protocols.
IEEE/ISO/IEC 8802-2 with SNAP
LLC
Data link
MAC IEEE 802.11
Figure 3: Protocols and DCC management entity comprising the data link layer
4.3.2 Decentralized congestion control
ETSI TS 102 687 [3] shall be fulfilled and the selected DCC algorithm shall respect the limits provided below.
The Channel Busy Ratio (CBR) is used for determining the transmission behaviour. CBR is an estimate of how much a
single channel is used based on listening on surrounding radio transmitters. The determination of CBR for the equipment
shall be as performed according to Equation 1. Any other equivalent mechanism may be used providing a CBR with a
deviation of ±3 %.
CBR , (1)
T is the period of time in milliseconds when the strength of received ITS-G5 signals over a period of T
busy CBR
exceeds -85 dBm. T is equal to 100 milliseconds. T is the duration of a transmission by the equipment and T is
CBR on off
the time i
...

SLOVENSKI STANDARD
01-marec-2020
Inteligentni transportni sistemi (ITS) - Specifikacija ITS-G5 dostopovne plasti pri
inteligentnih transportnih sistemih, ki delujejo v frekvenčnem pasu 5 GHz
Intelligent Transport Systems (ITS) - ITS-G5 Access layer specification for Intelligent
Transport Systems operating in the 5 GHz frequency band
Ta slovenski standard je istoveten z: ETSI EN 302 663 V1.3.1 (2020-01)
ICS:
35.240.60 Uporabniške rešitve IT v IT applications in transport
prometu
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
ITS-G5 Access layer specification for Intelligent Transport
Systems operating in the 5 GHz frequency band

2 ETSI EN 302 663 V1.3.1 (2020-01)

Reference
REN/ITS-0040191
Keywords
ITS, layer 1, layer 2, MAC, profile, radio

ETSI
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ETSI
3 ETSI EN 302 663 V1.3.1 (2020-01)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 7
3.1 Terms . 7
3.2 Symbols . 8
3.3 Abbreviations . 8
4 Access layer requirements . 9
4.1 Introduction . 9
4.2 Physical layer . 10
4.3 Data link layer . 11
4.3.1 Introduction. 11
4.3.2 Decentralized congestion control . 11
4.3.3 Logical link control . 11
4.3.4 Medium access control . 12
4.4 CEN DSRC and HDR DSRC protection . 12
5 ITS-G5 radio tests . 12
5.1 Radio tests defined in ETSI EN 302 571 . 12
5.2 Additional radio tests. 12
5.2.1 Dynamic receiver sensitivity. 12
Annex A (normative): Channel models for testing dynamic sensitivity values . 14
Annex B (informative): Data and management service . 16
B.1 Access layer data service . 16
B.2 Access layer management service . 16
Annex C (informative): Introduction to IEEE 802.11-2016. 17
C.1 Introduction . 17
C.2 Network topology . 18
C.3 Physical layer . 18
C.4 Medium access control . 19
C.4.1 Introduction . 19
C.4.2 Backoff procedure . 20
C.4.3 Medium access control . 20
C.4.4 EDCA parameters, AC and UP . 21
C.5 Implications of the dot11OCBActivated set to true . 23
Annex D (informative): Change History . 24
History . 25

ETSI
4 ETSI EN 302 663 V1.3.1 (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.
Foreword
This European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport Systems (ITS).

National transposition dates
Date of adoption of this EN: 23 December 2019
Date of latest announcement of this EN (doa): 31 March 2020
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 September 2020
Date of withdrawal of any conflicting National Standard (dow): 30 September 2020

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
5 ETSI EN 302 663 V1.3.1 (2020-01)
Introduction
The present document outlines the two lowest layers - physical layer and data link layer - in the protocol stack for
supporting vehicle-to-vehicle communications in an ad hoc network to be used at the 5,9 GHz frequency band allocated
in Europe in compliance with Commission Decision 2008/671/EC [i.1], ECC/DEC/(08)01 [i.2] and
ECC/REC/(08)01 [i.3]. The two lowest layers are termed access layer according to ETSI EN 302 665 [i.4] in the present
document and the technology specified for the access layer is collectively called ITS-G5. The ITS-G5 access layer
technology is using already existing standards for communications. The data link layer is divided into two sublayers;
medium access control and logical link control. The physical layer and the medium access control layer are covered in
IEEE 802.11-2016 [1]. The logical link control is based on the IEEE/ISO/IEC 8802-2-1998 [2]. The ITS-G5 standard
also adds features for Decentralized Congestion Control (DCC) methods ETSI TS 102 687 [3] to control the network
load.
By setting the Management Information Base (MIB) parameter dot11OCBActivated to true in
IEEE 802.11-2016 [1] a new capability is introduced namely the possibility to communicate outside the context of a
Basic Service Set (BSS), which is the smallest building block of an 802.11 network. Communication outside the BSS
implies that neither authentication/association procedures nor security mechanisms are supported. Further, no access
point functionality is present. The disable of these features also affects other built-in features of IEEE 802.11-2016 [1].
The requirement that nodes should share a common clock is no longer valid while dot11OCBActivated is true.
Further, scanning of available frequency channels for joining a BSS is also disabled implying that communication
outside the context of the BSS requires that a node is configured for a predetermined frequency channel where more
information about other available frequency channels can be obtained.

ETSI
6 ETSI EN 302 663 V1.3.1 (2020-01)
1 Scope
The present document defines the two lowest layers, physical layer and the data link layer, grouped into the access layer
of the ITS station reference architecture ETSI EN 302 665 [i.4].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
TM
[1] IEEE 802.11 -2016: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
[2] IEEE/ISO/IEC 8802-2-1998: "Information technology -- Telecommunications and information
exchange between systems -- Local and metropolitan area networks -- Specific requirements --
Part 2: Logical Link Control".
[3] ETSI TS 102 687 (V1.2.1): "Intelligent Transport Systems (ITS); Decentralized Congestion
Control Mechanisms for Intelligent Transport Systems operating in the 5 GHz range; Access layer
part".
TM
-2014: "IEEE Standard for Local and Metropolitan Area Networks: Overview and
[4] IEEE 802
Architecture".
[5] ETSI EN 302 571 (V2.1.1): "Intelligent Transport Systems (ITS); Radiocommunications
equipment operating in the 5 855 MHz to 5 925 MHz frequency band; Harmonised Standard
covering the essential requirements of article 3.2 of Directive 2014/53/EU".
[6] ETSI TS 102 792 (V1.2.1): "Intelligent Transport Systems (ITS); Mitigation techniques to avoid
interference between European CEN Dedicated Short Range Communication (CEN DSRC)
equipment and Intelligent Transport Systems (ITS) operating in the 5 GHz frequency range".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
ETSI
7 ETSI EN 302 663 V1.3.1 (2020-01)
[i.1] Commission Decision 2008/671/EC of 5 August 2008 on the harmonised use of radio spectrum in
the 5 875-5 905 MHz frequency band for safety-related applications of Intelligent Transport
Systems (ITS).
[i.2] ECC/DEC/(08)01: "ECC Decision (08)01 on the harmonised use of the band 5875-5925 MHz for
Intelligent Transport Systems (ITS)".
[i.3] ECC/REC/(08)01: "ECC Recommendation (08)01 on the use of the band 5855-5875 MHz for
Intelligent Transport Systems (ITS)".
[i.4] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture".
TM
[i.5] IEEE 802.11p -2010: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments".
TM
[i.6] IEEE 802.11 -2012: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
TM
[i.7] IEEE 802.11a -1999: "IEEE Standard for Telecommunications and Information Exchange
Between Systems - LAN/MAN Specific Requirements - Part 11: Wireless Medium Access Control
(MAC) and physical layer (PHY) specifications: High Speed Physical Layer in the 5 GHz band".
TM
[i.8] IEEE 802.11e -2005: "IEEE Standard for Information technology - Local and metropolitan area
networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications - Amendment: Medium Access Method (MAC) Quality of
Service Enhancements".
[i.9] ANSI/IEEE 802.1D-1998: "IEEE Standard for Information technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks - Common
specifications - Part 3: Media Access Control (MAC) Bridges".
[i.10] IEEE Registration Authority.
NOTE: Available at https://standards.ieee.org/content/ieee-standards/en/products-services/regauth/index.html.
[i.11] List of assigned EtherTypes at the IEEE Registration Authority.
NOTE: Available at http://standards-oui.ieee.org/ethertype/eth.txt.
[i.12] ETSI EN 302 636-4-1 (V1.3.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
[i.13] ETSI TS 103 175 (V1.1.1): "Intelligent Transport Systems (ITS); Cross Layer DCC Management
Entity for operation in the ITS G5A and ITS G5B medium".
TM
[i.14] IEEE 802.11 -2007: "IEEE Standard for Information Technology - Telecommunications and
Information Exchange Between Systems - Local and Metropolitan Area Networks - Specific
Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
ethertype: identifier to the network protocol above the data link layer
ETSI
8 ETSI EN 302 663 V1.3.1 (2020-01)
ITS-G5 access layer: access layer technology to be used in frequency bands dedicated for European Intelligent
Transport Systems (ITS)
3.2 Symbols
For the purposes of the present document, the following symbols apply:
aCWmax Maximum value of Contention Window
aCWmin Minimum value of Contention Window
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
aSIFSTime Short InterFrame Space defined by the physical layer
aSlotTime A slot time defined by the physical layer
CW Contention Window
CW Maximum value of Contention Window
max
CW Minimum value of Contention Window
min
T period of time the channel is busy
busy
T period of time
CBR
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Access Category
AC_BE Access Category Best Effort
AC_BK Access Category Background
AC_VI Access Category Video
AC_VO Access Category Voice
ACK Acknowledgment
AIFS Arbitration InterFrame Space
AIFSN Arbitration InterFrame Space Number
AP Access Point
BE Best Effort
BK Background
BPSK Binary Phase Shift Keying
BSS Basic Service Set
BSSID Basic Service Set Identification
CBR Channel Busy Ratio
CEN European Committee for Standardization
CSMA/CA Carrier Sense Multiple Access with Collision Avoidance
CW Contention Window
DCC Decentralized Congestion Control
DCF Distributed Coordination Function
DIFS Distributed InterFrame Space
DSRC Dedicated Short-Range Communication
DUT Device Under Test
ECC Electronic Communication Committee
EDCA Enhanced Distribution Coordination Access
EE Excellent Effort
EN European Norm
EPD EtherType Protocol Discrimination
GPS Global Positioning System
HalfBT Half Bathtub
HDR High Data Rate
IBSS Independent Basic Service Set
IEEE Institute of Electrical and Electronics Engineers
ITS Intelligent Transport Systems
LLC Logical Link Control
LOS Line-Of-Sight
ETSI
9 ETSI EN 302 663 V1.3.1 (2020-01)
MAC Medium Access Control
MCS Modulation and Coding Scheme
MIB Management Information Base
MPDU MAC Protocol Data Unit
NC Network Control
NLOS Non Line-Of-Sight
OFDM Orthogonal Frequency Division Multiplexing
PDU Protocol Data Unit
PER Packet Error Rate
PHY Physical layer
PLCP Physical Layer Convergence Protocol
PPDU PLCP Protocol Data Unit
PSDU PLCP Service Data Unit
QAM Quadrature Amplitude Modulation
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
SNAP SubNetwork Access Protocol
TDL Tapped Delay Line
TS Technical Specification
TX Transmitter
UP User Priority
VI Video
VO Voice
WLAN Wireless Local Area Network
4 Access layer requirements
4.1 Introduction
The access layer bundles the data link layer and the physical layer and it is situated at the bottom of the ITS protocol
stack, see Figure 1. The ITS station reference architecture and the definition of an ITS station are outlined in ETSI
EN 302 665 [i.4].
Applications
ITS applications
Facilities
Data link
Networking &
Protocols
Transport
Physical
Access
Figure 1: ITS station reference architecture
The access layer technology consists of IEEE 802.11-2016 [1], IEEE/ISO/IEC 8802-2-1998 [2], IEEE 802-2014 [4] and
ETSI TS 102 687 [3], see Figure 2. An introduction to IEEE 802.11-2016 [1] with the MIB parameter
dot11OCBActivated set to true is provided in informative Annex C. Interfaces between access layer and
management entity and access layer and networking & transport layer are found in Annex B.
ETSI
Management
Security
10 ETSI EN 302 663 V1.3.1 (2020-01)
IEEE/ISO/IEC 8802-2 with SNAP
Data link
IEEE 802.11
Access
Physical IEEE 802.11
Figure 2: Protocols comprising the access layer
4.2 Physical layer
The physical layer of ITS-G5 shall be the orthogonal frequency division multiplexing (OFDM) "half-clocked" operation
using 10 MHz frequency channels as outlined in IEEE 802.11-2016 [1], clause 17. Mandatory transfer rates are
3 Mbit/s, 6 Mbit/sand 12 Mbit/s.
The limits for static receiver sensitivity shall be as outlined in Table 1.
Table 1: Static receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
3 BPSK 1/2 -91
4,5 BPSK 3/4 -90
6 QPSK 1/2 -88
9 QPSK 3/4 -86
12 16-QAM 1/2 -83
18 16-QAM 3/4 -79
24 64-QAM 2/3 -75
27 64-QAM 3/4 -74
The limits for dynamic receiver sensitivity (i.e. the receiver sensitivity in the presence of interference) shall be as
outlined in Table 2.
Table 2: Dynamic receiver sensitivity
Transfer rate Minimum sensitivity for 10 MHz
Modulation Coding rate
(Mbit/s) channel spacing (dBm)
6 QPSK 1/2 -85
The limits for receiver adjacent channel rejection and alternate adjacent channel rejection shall be as outlined in
Table 3.
Table 3: Limits for receiver adjacent channel rejection and
alternate adjacent channel rejection
Alternate adjacent
Transfer rate Adjacent channel
Modulation Coding rate channel rejection
(Mbit/s) rejection (dB)
(dB)
3 BPSK 1/2 28 42
4,5 BPSK 3/4 27 41
6 QPSK 1/2 25 39
9 QPSK 3/4 23 37
12 16-QAM 1/2 20 34
18 16-QAM 3/4 16 30
24 64-QAM 2/3 12 26
27 64-QAM 3/4 11 25
ETSI
ETSI
TS 102 687
11 ETSI EN 302 663 V1.3.1 (2020-01)
4.3 Data link layer
4.3.1 Introduction
The data link layer consists of two sublayers - logical link control (LLC) and medium access control (MAC) - where the
former provides means for distinguishing between different network layer protocols and the latter is responsible for
scheduling transmissions to minimize interference between ITS stations. Decentralized Congestion Control (DCC) is a
management entity controlling the network load by for example regulating the number of transmission opportunities the
ITS station has based on the current load. Thus DCC is not a protocol to achieve interoperability but merely an
algorithm controlling that a single ITS station does not consume all resources on the channel. Figure 3 illustrates the
different sublayers and protocols.
IEEE/ISO/IEC 8802-2 with SNAP
LLC
Data link
MAC IEEE 802.11
Figure 3: Protocols and DCC management entity comprising the data link layer
4.3.2 Decentralized congestion control
ETSI TS 102 687 [3] shall be fulfilled and the selected DCC algorithm shall respect the limits provided below.
The Channel Busy Ratio (CBR) is used for determining the transmission behaviour. CBR is an estimate of how much a
single channel is used based on listening on surrounding radio transmitters. The determination of CBR for the equipment
shall be as performed according to Equation 1
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