SIST EN 302 636-5-1 V2.2.1:2019

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
Vehicular Communications;
GeoNetworking;
Part 5: Transport Protocols;
Sub-part 1: Basic Transport Protocol

2 ETSI EN 302 636-5-1 V2.2.1 (2019-05)

Reference
REN/ITS-00360
Keywords
addressing, autonomic networking, ITS, network,
protocol
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.
TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.
TM TM
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 302 636-5-1 V2.2.1 (2019-05)
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 . 7
3.3 Abbreviations . 7
4 Services provided by the Basic Transport Protocol . 8
5 Format convention . 9
6 BTP packet structure . 9
7 BTP header . 9
7.1 Overview . 9
7.2 BTP-A header . 10
7.2.1 Structure of the BTP-A header . 10
7.2.2 Fields of the BTP-A header . 10
7.3 BTP-B header . 10
7.3.1 Structure of the BTP-B header . 10
7.3.2 Fields of the BTP-B header . 11
8 Protocol operations . 11
8.1 General . 11
8.2 Source operations . 11
8.3 Destination operations . 12
Annex A (informative): BTP data services . 14
A.1 General . 14
A.2 BTP-Data.request . 14
A.3 BTP-Data.indication . 15
Annex B (informative): Bibliography . 17
History . 18

ETSI
4 ETSI EN 302 636-5-1 V2.2.1 (2019-05)
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).
The present document is part 5, sub-part 1 of a multi-part deliverable. Full details of the entire series can be found in
part 1 [2].
National transposition dates
Date of adoption of this EN: 16 May 2019
Date of latest announcement of this EN (doa): 31 August 2019
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 29 February 2020
Date of withdrawal of any conflicting National Standard (dow): 29 February 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 302 636-5-1 V2.2.1 (2019-05)
Introduction
The Basic Transport Protocol (BTP) provides an end-to-end, connection-less transport service in the ITS ad hoc
network. Its main purpose is the multiplexing of messages from different processes at the ITS facilities layer, e.g. CAM
and DENM from the cooperative awareness basic service and the distributed environmental notification basic service,
for the transmission of packets via the GeoNetworking protocol as well as the de-multiplexing at the destination. BTP
enables protocol entities at the ITS facilities layer to access services of the GeoNetworking protocol and to pass
protocol control information between the ITS facilities layer and the GeoNetworking protocol.
Message multiplexing/demultiplexing is based on ports, an ITS station-internal 16 bit address. A port represents a
communication endpoint that identifies the ITS station protocol entity at the source (source port) or the destination
(destination port). The usage of ports is similar to the two-stage packet transport in the IP protocol suite, where the IP
provides the routing of packets from source to destination and the transport protocol, such as UDP,
multiplexes/demultiplexes messages from/to application processes. In the case of BTP, the GeoNetworking protocol
transports the packets among the ITS stations and the BTP protocol delivers the packets to the entities at the ITS
facilities layer. BTP also adopts the concept of "well-known ports" from the IP protocol suite that assigns fixed ports to
specific ITS facilities layer protocols. The definition of the ports, however, is beyond the scope of the present
document.
BTP is a lightweight protocol: it has a 4-byte protocol header and requires minimal processing. It provides an unreliable
transport of packets, i.e. packets can arrive out-of-order, appear duplicated or can be lost. The design of BTP assumes
that entities using the protocol are either tolerant against the unreliable packet transport or provide appropriate
mechanisms for reliable communication in their protocols.
ETSI
6 ETSI EN 302 636-5-1 V2.2.1 (2019-05)
1 Scope
The present document specifies the Basic Transport Protocol (BTP) for the transport of packets among ITS stations. It
resides on top of the GeoNetworking protocol specified in ETSI EN 302 636-4-1 [5] and below the ITS-S facilities
layer. It provides an end-to-end, connection-less and unreliable transport service.
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.
[1] ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".
[2] ETSI EN 302 636-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 1: Requirements".
[3] ETSI EN 302 636-2: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 2: Scenarios".
[4] ETSI EN 302 636-3: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 3: Network architecture".
[5] ETSI EN 302 636-4-1: "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".
[6] ETSI TS 103 248: "Intelligent Transport Systems (ITS); GeoNetworking; Port Numbers for the
Basic Transport Protocol (BTP)".
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.
[i.1] Void.
[i.2] Void.
[i.3] ETSI EN 302 637-2: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 2: Specification of Cooperative Awareness Basic Service".
ETSI
7 ETSI EN 302 636-5-1 V2.2.1 (2019-05)
[i.4] ETSI EN 302 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic
Service".
[i.5] IETF RFC 768: "User Datagram Protocol".
[i.6] Void.
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in ETSI EN 302 665 [1], ETSI EN 302 636-3 [4] and the
following apply:
BTP-PDU: PDU exchanged between BTP peer entities
destination: receiving BTP entity in the ITS station
destination port: port identifying the destination's protocol entity at the ITS facilities layer
NOTE: Facilities layer services that do not expect replies either do not include a source port number in the
header, or they set it to a default (usually 0) to indicate no reply port available. For session-based services
(client-server or peer-to-peer), the source port is often set to a value from an ephemeral (dynamically
assigned) subspace of the space of all port numbers.
GN-PDU: PDU exchanged between peer entities of the GeoNetworking protocol
ITS-FPCI: control information passed from the ITS Facilities layer to the BTP
port: ITS station-internal address that identifies a protocol entity at the ITS facilities layer and represents an endpoint of
a logical connection
source: originating BTP entity in the ITS station
source port: port number to be used by a facilities layer entity as the destination port in a subsequent reply to the
originator
NOTE: Such an entity may be listening for a reply BTP packet.
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the abbreviations given in ETSI EN 302 665 [1], ETSI EN 302 636-3 [4] and
the following apply:
BTP Basic Transport Protocol
BTP-PDU Basic Transport Protocol Protocol Data Unit
BTP-SAP Basic Transport Protocol Service Access Point
GN-PDU GeoNetworking protocol PDU exchanged between peer entities of the GeoNetworking protocol
GN-SAP GeoNetworking Service Access Point
ITS-FPCI ITS Facilities layer Protocol Control Information
ITS-FPDU ITS Facilities layer Protocol Data Unit
ITS-FSDU ITS Facilities layer Service Data Unit
LL Link Layer
PCI Protocol Control Information
PDU Protocol Data Unit
ETSI
8 ETSI EN 302 636-5-1 V2.2.1 (2019-05)
SHB Single Hop Broadcast
TSB Topologically Scoped Broadcast
4 Services provided by the Basic Transport Protocol
The Basic Transport Protocol (BTP) provides an end-to-end, connection-less transport service in the ITS ad hoc
network (ETSI EN 302 636-3 [4]). Similar to UDP (IETF RFC 768 [i.5]), it offers a minimal transport service, i.e. the
non-guaranteed delivery of BTP-PDUs among BTP entities. It also allows protocol entities at the ITS facilities layer to
directly access the services provided by the GeoNetworking protocol.
The BTP shall meet the requirements specified in ETSI EN 302 665 [1] and ETSI EN 302 636-1 [2] and support the use
cases defined in ETSI EN 302 636-2 [3].
The BTP provides services to ITS facilities layer protocol entities (figure 1), such as cooperative awareness basic
service (ETSI EN 302 637-2 [i.3]) and DEN basic service (ETSI EN 302 637-3 [i.4]). The services are provide
...

SLOVENSKI
STANDARD SIST EN 302 636-5-1 V2.2.1:201901-julij-2019Inteligentni transportni sistemi (ITS) - Komunikacije med vozili - Geomreženje - 5. del: Transportni protokoli - 1. poddel: Osnovni transportni protokolIntelligent Transport Systems (ITS) - Vehicular Communications - GeoNetworking - Part 5: Transport Protocols - Sub-part 1: Basic Transport ProtocolTa slovenski standard je istoveten z:ETSI EN 302 636-5-1 V2.2.1 (2019-05)35.240.60Uporabniške rešitve IT v prometuIT applications in transportICS:SIST EN 302 636-5-1 V2.2.1:2019en2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)2
Reference REN/ITS-00360 Keywords addressing, autonomic networking, ITS, network, protocol 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.
DECTTM, PLUGTESTSTM, UMTSTM and the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETM 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. SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)3 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 . 7 3.3 Abbreviations . 7 4 Services provided by the Basic Transport Protocol . 8 5 Format convention . 9 6 BTP packet structure . 9 7 BTP header . 9 7.1 Overview . 9 7.2 BTP-A header . 10 7.2.1 Structure of the BTP-A header . 10 7.2.2 Fields of the BTP-A header . 10 7.3 BTP-B header . 10 7.3.1 Structure of the BTP-B header . 10 7.3.2 Fields of the BTP-B header . 11 8 Protocol operations . 11 8.1 General . 11 8.2 Source operations . 11 8.3 Destination operations . 12 Annex A (informative):
BTP data services . 14 A.1 General . 14 A.2 BTP-Data.request . 14 A.3 BTP-Data.indication . 15 Annex B (informative):
Bibliography . 17 History . 18
ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)4 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). The present document is part 5, sub-part 1 of a multi-part deliverable. Full details of the entire series can be found in part 1 [2].
National transposition dates Date of adoption of this EN: 16 May 2019 Date of latest announcement of this EN (doa): 31 August 2019 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
29 February 2020 Date of withdrawal of any conflicting National Standard (dow): 29 February 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. SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)5 Introduction The Basic Transport Protocol (BTP) provides an end-to-end, connection-less transport service in the ITS ad hoc network. Its main purpose is the multiplexing of messages from different processes at the ITS facilities layer, e.g. CAM and DENM from the cooperative awareness basic service and the distributed environmental notification basic service, for the transmission of packets via the GeoNetworking protocol as well as the de-multiplexing at the destination. BTP enables protocol entities at the ITS facilities layer to access services of the GeoNetworking protocol and to pass protocol control information between the ITS facilities layer and the GeoNetworking protocol. Message multiplexing/demultiplexing is based on ports, an ITS station-internal 16 bit address. A port represents a communication endpoint that identifies the ITS station protocol entity at the source (source port) or the destination (destination port). The usage of ports is similar to the two-stage packet transport in the IP protocol suite, where the IP provides the routing of packets from source to destination and the transport protocol, such as UDP, multiplexes/demultiplexes messages from/to application processes. In the case of BTP, the GeoNetworking protocol transports the packets among the ITS stations and the BTP protocol delivers the packets to the entities at the ITS facilities layer. BTP also adopts the concept of "well-known ports" from the IP protocol suite that assigns fixed ports to specific ITS facilities layer protocols. The definition of the ports, however, is beyond the scope of the present document. BTP is a lightweight protocol: it has a 4-byte protocol header and requires minimal processing. It provides an unreliable transport of packets, i.e. packets can arrive out-of-order, appear duplicated or can be lost. The design of BTP assumes that entities using the protocol are either tolerant against the unreliable packet transport or provide appropriate mechanisms for reliable communication in their protocols. SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)6 1 Scope The present document specifies the Basic Transport Protocol (BTP) for the transport of packets among ITS stations. It resides on top of the GeoNetworking protocol specified in ETSI EN 302 636-4-1 [5] and below the ITS-S facilities layer. It provides an end-to-end, connection-less and unreliable transport service. 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. [1] ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture". [2] ETSI EN 302 636-1: "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 1: Requirements". [3] ETSI EN 302 636-2: "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 2: Scenarios". [4] ETSI EN 302 636-3: "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 3: Network architecture". [5] ETSI EN 302 636-4-1: "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". [6] ETSI TS 103 248: "Intelligent Transport Systems (ITS); GeoNetworking; Port Numbers for the Basic Transport Protocol (BTP)". 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. [i.1] Void. [i.2] Void. [i.3] ETSI EN 302 637-2: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service". SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)7 [i.4] ETSI EN 302 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic Service". [i.5] IETF RFC 768: "User Datagram Protocol". [i.6] Void. 3 Definition of terms, symbols and abbreviations 3.1 Terms For the purposes of the present document, the terms given in ETSI EN 302 665 [1], ETSI EN 302 636-3 [4] and the following apply: BTP-PDU: PDU exchanged between BTP peer entities destination: receiving BTP entity in the ITS station destination port: port identifying the destination's protocol entity at the ITS facilities layer NOTE: Facilities layer services that do not expect replies either do not include a source port number in the header, or they set it to a default (usually 0) to indicate no reply port available. For session-based services (client-server or peer-to-peer), the source port is often set to a value from an ephemeral (dynamically assigned) subspace of the space of all port numbers. GN-PDU: PDU exchanged between peer entities of the GeoNetworking protocol ITS-FPCI: control information passed from the ITS Facilities layer to the BTP port: ITS station-internal address that identifies a protocol entity at the ITS facilities layer and represents an endpoint of a logical connection source: originating BTP entity in the ITS station source port: port number to be used by a facilities layer entity as the destination port in a subsequent reply to the originator NOTE: Such an entity may be listening for a reply BTP packet. 3.2 Symbols Void. 3.3 Abbreviations For the purposes of the present document, the abbreviations given in ETSI EN 302 665 [1], ETSI EN 302 636-3 [4] and the following apply: BTP Basic Transport Protocol BTP-PDU Basic Transport Protocol Protocol Data Unit BTP-SAP Basic Transport Protocol Service Access Point GN-PDU GeoNetworking protocol PDU exchanged between peer entities of the GeoNetworking protocol GN-SAP GeoNetworking Service Access Point ITS-FPCI ITS Facilities layer Protocol Control Information ITS-FPDU ITS Facilities layer Protocol Data Unit ITS-FSDU ITS Facilities layer Service Data Unit LL Link Layer PCI Protocol Control Information PDU Protocol Data Unit SIST EN 302 636-5-1 V2.2.1:2019

ETSI ETSI EN 302 636-5-1 V2.2.1 (2019-05)8 SHB Single Hop Broadcast TSB Topologically Scoped Broadcast 4 Services provided by the Basic Transport Protocol The Basic Transport Protocol (BTP) provides an end-to-end, connection-less transport service in the ITS ad hoc network (ETSI EN 302 636-3 [4]). Similar to UDP (IETF RFC 768 [i.5]), it offers a minimal transport service, i.e. the non-guaranteed delivery of BTP-PDUs among BTP entities. It also allows protocol entiti
...