ETSI TS 103 836-4-1 V2.2.1 (2026-05)

TECHNICAL SPECIFICATION
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;
Release 2
2 ETSI TS 103 836-4-1 V2.2.1 (2026-04)

Reference
RTS/ITS-00100
Keywords
architecture, ITS
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All rights reserved.
ETSI
3 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
Contents
Intellectual Property Rights . 8
Foreword . 8
Modal verbs terminology . 9
Introduction . 9
1 Scope . 10
2 References . 10
2.1 Normative references . 10
2.2 Informative references . 10
3 Definition of terms, symbols and abbreviations . 11
3.1 Terms . 11
3.2 Symbols . 12
3.3 Abbreviations . 12
4 Services provided by the GeoNetworking protocol . 14
5 Format convention . 15
6 GeoNetworking address . 15
6.1 General . 15
6.2 GeoNetworking address format . 15
6.3 Fields of the GeoNetworking address . 16
7 Security and privacy . 17
8 Data structures . 17
8.1 General . 17
8.2 Location table . 17
8.2.1 General . 17
8.2.2 Minimum data elements of a Location Table Entry . 17
8.2.3 Maintenance of the Location Table . 18
8.3 Ego Position Vector. 18
8.3.1 General . 18
8.3.2 Minimum data elements . 18
8.3.3 Maintenance . 18
8.4 Sequence number . 19
8.4.1 General . 19
8.4.2 Maintenance . 19
8.5 Location service packet buffer . 19
8.5.1 General . 19
8.5.2 Buffer size . 19
8.5.3 Maintenance . 19
8.6 Forwarding packet buffer . 20
8.6.1 General . 20
8.6.2 Buffer size . 20
8.6.3 Maintenance . 20
9 GeoNetworking packet structure and formats . 21
9.1 Overview . 21
9.2 Packet structure . 21
9.2.1 General . 21
9.2.2 Overall packet structure . 21
9.2.3 Maximum Transmit Unit . 22
9.3 GeoNetworking header structure . 22
9.4 GeoNetworking Secured Packet . 22
9.5 Position vectors . 22
9.5.1 Overview . 22
9.5.2 Long Position Vector . 23
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9.5.2.1 Structure . 23
9.5.2.2 Fields . 23
9.5.3 Short Position Vector . 24
9.5.3.1 Structure . 24
9.5.3.2 Fields . 24
9.6 Basic Header . 24
9.6.1 Composition of the Basic Header . 24
9.6.2 Fields of the Basic Header . 25
9.6.3 Encoding of the NH field in the Basic Header . 25
9.6.4 Encoding of the LT field . 25
9.7 Common Header . 26
9.7.1 Composition of the Common Header . 26
9.7.2 Fields of the Common Header . 26
9.7.3 Encoding of the NH field in the Common Header . 27
9.7.4 Encoding of the HT and HST fields . 27
9.7.5 Encoding of the TC field . 28
9.8 GeoNetworking packet header types . 28
9.8.1 Overview . 28
9.8.2 GUC packet header . 28
9.8.2.1 Composition of the GUC packet header. 28
9.8.2.2 Fields of the GUC packet header . 29
9.8.3 TSB packet header . 29
9.8.3.1 Composition of the TSB packet header . 29
9.8.3.2 Fields of the TSB packet header . 30
9.8.4 SHB packet header. 30
9.8.4.1 Composition of the SHB packet header . 30
9.8.4.2 Fields of the SHB packet header . 31
9.8.5 GBC/GAC packet header . 31
9.8.5.1 Composition of the GBC/GAC packet header . 31
9.8.5.2 Fields of the GBC/GAC packet header . 32
9.8.6 BEACON packet header . 32
9.8.6.1 Composition of the BEACON packet header . 32
9.8.6.2 Fields of the BEACON packet header . 33
9.8.7 LS Request packet header . 33
9.8.7.1 Composition of the LS Request packet header. 33
9.8.7.2 Fields of the LS Request packet header . 34
9.8.8 LS Reply packet header . 34
9.8.8.1 Composition of the LS Reply packet header . 34
9.8.8.2 Fields of the LS Reply packet header . 35
10 Protocol operation . 35
10.1 General . 35
10.2 Network management . 36
10.2.0 Overview . 36
10.2.1 Address configuration . 36
10.2.1.1 General . 36
10.2.1.2 Auto-address configuration . 37
10.2.1.3 Managed address configuration . 37
10.2.1.3.1 General Requirements . 37
10.2.1.3.2 Initial address configuration . 37
10.2.1.3.3 Address update . 37
10.2.1.4 Anonymous address configuration . 37
10.2.1.5 Duplicate address detection . 38
10.2.2 Ego position vector and time update . 38
10.2.2.1 Overview . 38
10.2.2.2 Ego Position Vector update . 38
10.2.2.3 Time update. 38
10.2.3 Beaconing . 39
10.2.4 Location service . 39
10.3 Packet handling . 40
10.3.1 Overview . 40
10.3.2 Basic Header field settings . 41
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10.3.3 Basic Header processing . 41
10.3.4 Common Header field settings. 43
10.3.5 Common Header processing . 44
10.3.6 Beacon packet handling . 44
10.3.6.1 General . 44
10.3.6.2 Source operations . 44
10.3.6.3 Receiver operations . 46
10.3.7 Location service packet handling . 46
10.3.7.1 Source operations . 46
10.3.7.1.1 Overview . 46
10.3.7.1.2 Operation for initial LS Request . 46
10.3.7.1.3 Operation for LS Request re-transmission. 47
10.3.7.1.4 Operation for LS Reply . 48
10.3.7.2 Forwarder operations . 48
10.3.7.3 Destination operations . 48
10.3.8 GUC packet handling. 50
10.3.8.1 General . 50
10.3.8.2 Source operations . 50
10.3.8.3 Forwarder operations . 52
10.3.8.4 Destination operations . 53
10.3.9 TSB packet handling . 54
10.3.9.1 General . 54
10.3.9.2 Source operations . 55
10.3.9.3 Forwarder and receiver operations . 56
10.3.10 SHB packet handling . 57
10.3.10.1 General . 57
10.3.10.2 Source operations . 58
10.3.10.3 Receiver operations . 59
10.3.11 GBC packet handling . 60
10.3.11.1 General . 60
10.3.11.2 Source operations . 60
10.3.11.3 Forwarder and receiver operations . 61
10.3.12 GAC packet handling. 63
10.3.12.1 General . 63
10.3.12.2 Source operations . 63
10.3.12.3 Forwarder and receiver operations . 63
10.4 MCO management . 65
10.4.1 Overview . 65
10.4.2 MCO Parameters Updates (MPU) . 66
10.4.2.1 Overview . 66
10.4.2.2 GAGH state . 66
10.4.2.3 GAGH state update . 66
10.4.3 Network Updates (NU) . 67
10.4.3.1 Overview . 67
10.4.3.2 Access layer update . 67
10.4.3.3 Network updates to the Facilities layer . 67
10.4.4 ALI Request Handler (ARH) . 68
Annex A (normative): Duplicate Packet Detection . 69
A.1 General . 69
A.2 SEQN-based duplicate packet detection . 69
Annex B (normative): Packet data rate and geographical area size control . 70
B.1 Overview . 70
B.2 Packet data rate control . 70
B.3 Geographical area size control . 70
Annex C (normative): Position vector update . 71
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6 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
C.1 Overview . 71
C.2 Update of LocT position vector . 71
C.3 Update of GeoNetworking packet position vector . 72
Annex D (normative): GeoNetworking forwarding algorithm selection procedure . 73
Annex E (normative): Non-area forwarding algorithms . 75
E.1 Overview . 75
E.2 Greedy forwarding algorithm . 75
E.3 Non-area contention-based forwarding algorithm . 76
E.3.1 Overview . 76
E.3.2 Calculation of non-area CBF timeout for newly received GN packets . 77
E.3.2.1 Overview . 77
E.3.2.2 Calculation of the segment number SEGN . 78
E.3.2.3 Calculation of non-area CBF timeout without Access Layer constraints . 78
E.3.2.4 Calculation of non-area CBF timeout with Access Layer constraint . 79
E.3.3 Recalculation of non-area CBF timeout upon reception of a forwarded packet . 79
E.3.4 Activity diagram . 80
E.3.5 Pseudo code . 82
Annex F (normative): Area forwarding algorithms . 84
F.1 Overview . 84
F.2 Simple GeoBroadcast forwarding algorithm . 84
F.3 Area contention-based forwarding algorithm . 84
F.3.1 Overview . 84
F.3.2 Calculation of area CBF timeout for newly received GN packets . 85
F.3.2.1 Overview . 85
F.3.2.2 Calculation of the segment number SEGN . 85
F.3.2.3 Calculation of area CBF timeout without Access Layer constraints . 86
F.3.2.4 Calculation of area CBF timeout with Access Layer constraint . 86
F.3.3 Recalculation of area CBF timeout upon reception of a forwarded packet . 86
F.3.4 Activity diagram . 87
F.3.5 Pseudo code . 89
Annex G (normative): GeoNetworking traffic classification . 90
Annex H (normative): GeoNetworking protocol constants . 91
Annex I (informative): ASN.1 specification of the GeoNetworking MIB. 93
Annex J (informative): GeoNetworking data interface . 94
J.1 General . 94
J.2 TRANSP_CORE.request . 94
J.3 TRANSP_CORE.confirm . 95
J.4 TRANSP_CORE.indication . 96
Annex K (informative): GeoNetworking management services . 98
K.1 General . 98
K.2 CORE_MMT.request . 98
K.3 CORE_MMT.response . 98
K.4 CORE_GAGH.indication . 99
Annex L (informative): MCO_NET services for the GN Core . 100
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L.1 General . 100
L.2 CORE_MCO.request . 100
L.3 CORE_MCO.response . 100
L.4 CORE_MCO.indication . 101
Annex M (informative): MCO_NET services for the GAGHs . 102
M.1 General . 102
M.2 GAGH_MCO.request . 102
M.3 GAGH_MCO.indication . 102
Annex N (informative): MCO services for the Facilities layer . 103
N.1 General . 103
N.2 MCO_FAC_NET.request . 103
N.3 MCO_FAC_NET.indication . 103
N.4 MCO_FAC_NET.response . 104
Annex O (informative): Bibliography . 105
Annex P (informative): Change history . 106
History . 107

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8 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
Intellectual Property Rights
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pertaining to these essential IPRs, if any, are 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 IPR online database.
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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.
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Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Intelligent Transport Systems
(ITS).
The present document is part 4, sub-part 1 of a multi-part deliverable covering the Vehicular Communications;
GeoNetworking, as identified below:
Part 1: "Requirements";
Part 2: "Scenarios";
Part 3: "Network Architecture";
Part 4: "Geographical addressing and forwarding for point-to-point and point-to-multipoint
communications";
Sub-part 1: "Media-independent functionality";
Sub-part 2: "Media-dependent functionalities for ITS-G5";
Sub-part 3: "Media-dependent functionalities for NR-V2X PC5 and LTE-V2X PC5";
Part 5: "Transport Protocols";
Part 6: "Internet Integration".
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9 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
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.
Introduction
The GeoNetworking protocol is a network layer protocol that provides packet routing in an ad hoc network. It makes
use of geographical positions for packet transport. GeoNetworking supports the communication among individual ITS
stations as well as the distribution of packets in geographical areas.
GeoNetworking can be executed over different ITS access technologies for short-range wireless technologies, such as
ITS-G5 and infrared. The ITS access technologies for short-range wireless technologies have many technical
commonalities, but also differences. In order to reuse the GeoNetworking protocol specification for multiple ITS access
technologies, the specification is separated into media-independent and media-dependent functionalities.
Media-independent functionalities are those which are common to all ITS access technologies for short-range wireless
communication to be used for GeoNetworking. The media-dependent functionalities extend the media-independent
functionality for a specific ITS access technology. Therefore, the GeoNetworking protocol specification consists of the
standard for media-independent functionality and at least one standard for media-dependent functionality. However, it
should be noted that the media-dependent extensions do not represent distinct protocol entities.

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10 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
1 Scope
The present document specifies the Release 2 of the GeoNetworking protocol. Compared to the Release 1 specification,
Release 2 primarily adds support for multi-channel operation.
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 in the
ETSI docbox.
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.
[1] ETSI TS 103 899: "Intelligent Transport Systems (ITS); Vehicular Communications;
Geographical Area Definition; Release 2".
[2] ETSI TS 102 894-2: "Intelligent Transport Systems (ITS); Facilities Layer; Part 2: Common Data
Dictionary (CDD); Release 2".
[3] ETSI TS 103 836-5-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol; Release 2".
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 may be useful in implementing an ETSI deliverable or add to the reader's
understanding, but are not required for conformance to the present document.
[i.1] ETSI TS 103 836-3: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 3: Network architecture; Release 2".
[i.2] ETSI TS 103 697 (V2.1.1): "Intelligent Transport Systems (ITS); Architecture; Multi-Channel
Operation (MCO) for Cooperative ITS (C-ITS); Release 2".
[i.3] National Imagery and Mapping Agency (NIMA), US Department of Defense: "World Geodetic
System 1984 - Its Definition and Relation with Local Geodetic Systems", Third Edition -
Amendment 1, NIMA TR 8350.2.
[i.4] Void.
[i.5] IEEE 802.3™:2008: "IEEE Standard for Information Technology - Telecommunications and
information exchange between systems-Local and metropolitan area networks - Specific
requirements - Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
Access Method and Physical Layer Specifications".
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11 ETSI TS 103 836-4-1 V2.2.1 (2026-04)
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