Internet DRAFT - draft-petrescu-its-cacc-sdo
draft-petrescu-its-cacc-sdo
Network Working Group A. Petrescu, Ed.
Internet-Draft CEA, LIST
Intended status: Informational J. Huang
Expires: October 20, 2016 Huawei Technologies
T. Ernst
Mines ParisTech
R. Buddenberg
Retired
C. Perkins
Futurewei
April 18, 2016
Cooperative Adaptive Cruise Control and Platooning at SDOs and Gap
Analysis
draft-petrescu-its-cacc-sdo-05.txt
Abstract
This document describes the use-cases of Cooperative Adaptive Cruise
Control, and Platooning, as defined by several Standards Development
Organizations such as ETSI, IEEE P1609, SAE, 3GPP, ISO and FirstNet.
C-ACC and Platooning involve concepts of direct vehicle-to-vehicle,
and device-to-device communications, which are developed by 3GPP
following on work done within the METIS EU project. They are
illustrated very clearly in emergency settings such as FirstNet.
IP packets - instead of link-layer frames - are pertinent for C-ACC
and Platooning use-cases because applications for road safety such as
WAZE, iRezQ and Coyote (currently involving infrastructure) make use
of IP messages, and have proved successful in deployments.
Applications such as Sentinel operate directly between vehicles, but
currently use messages not carried over IP.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
Petrescu, et al. Expires October 20, 2016 [Page 1]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 20, 2016.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. ETSI ITS C-ACC and Platooning use-case and reqs . . . . . . . 7
4. The C-ACC Use of Protocols specified by IEEE 1609 Standards . 7
5. SAE perspective on C-ACC and Platooning . . . . . . . . . . . 8
6. 3GPP and EU projects using LTE Device-to-Device concepts . . 8
6.1. 3GPP . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.2. METIS . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. ISO perspective on V2V . . . . . . . . . . . . . . . . . . . 10
8. ISO-IEEE Harmonization . . . . . . . . . . . . . . . . . . . 11
9. V2V communications at ITU . . . . . . . . . . . . . . . . . . 12
10. ARIB and ITS Info-comm use of CACC and V2V concepts . . . . . 13
11. FirstNet EMS use of LTE and IP in V2I2V . . . . . . . . . . . 13
12. Internet apps: WAZE, iRezQ, Coyote, Sentinel . . . . . . . . 14
13. Car manufacturer labels with V2V features . . . . . . . . . . 14
14. Gap Analysis . . . . . . . . . . . . . . . . . . . . . . . . 15
14.1. Neighbor Discovery protocol . . . . . . . . . . . . . . 15
14.2. Mobile IP protocol . . . . . . . . . . . . . . . . . . . 15
14.3. AODVv2 protocol . . . . . . . . . . . . . . . . . . . . 16
15. Security Considerations . . . . . . . . . . . . . . . . . . . 16
16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
17. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17
18. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
18.1. Normative References . . . . . . . . . . . . . . . . . . 17
18.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 19
Petrescu, et al. Expires October 20, 2016 [Page 2]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
Cooperative Adaptive Cruise Control (C-ACC) and Platooning are two
use-cases described recently by other Standards Development
Organizations (SDOs). C-ACC [CACC-def] is understood as a automated
formation of chains of automobiles following each other at constant
speed. This offers more comfort for human drivers on long journeys
on straight roads.
Simple 'cruise control' was the automation of speed maintenance at a
single automobile (increase torque if uphill, smoothly brake
downhill, such as to maintain constant speed). The term "Adaptive
Cruise Control" was used earlier in the literature [ACC-def]. The
concept of C-ACC aims at the same level of automation but in a
cooperative manner between several vehicles: while in CC mode, when a
vehicle in front slowly decelerates, this vehicle will also do, such
as to maintain distance, and relieve driver from taking control over.
Platooning is another concept related to larger vehicles following
each other. The goal in this case is more than just comfort - large
gains are expected in terms of gas consumption: when large vehicles
can follow each other at small distance the air-drag is much lower,
reducing gas consumption, tyre use, and more.
Both C-ACC and Platooning must rely on wireless communications
between vehicles (in addition to more immediate indicators like
signal echoes - radars and cameras). These exchanges may happen in a
direct manner (direct vehicle to vehicle communications) or with
assistance from a fixed communication infrastructure (vehicle-to-
infrastructure-to-vehicle communications).
This document presents the V2V-based C-ACC and Platooning use-cases
as described at ETSI [ETSI-CACC], SAE [SAE-V2V], ISO [ISO-CACC], 3GPP
[GPP-TR-22-885], ITU [ITU-V2V], ITS Info-communications Forum of
Japan [its-infocomm-CACC] and more. These use-cases are widely
accepted as examples of Vehicle-to-Vehicle applications.
In emergency settings the concepts of direct vehicle-to-vehicle
communications are of paramount importance. FirstNet, as described
later in this document, covers V2V, V2I and V2I2V communication
needs, together with strong security requirements.
In the market, several systems for vehicular communications have
demonstrated a number of benefits in the context of vehicle-to-
vehicle communications.
Petrescu, et al. Expires October 20, 2016 [Page 3]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
o The Sentinel system is used between vehicles to warn each other
about approach;
o WAZE on smartphones created a community where users influence
others about the route choice;
o iRezQ and Coyote communicate between vehicles, via infrastructure,
about route risks.
In [I-D.petrescu-ipv6-over-80211p] the use of IPv6 over 802.11p is
described. This link layer is potentially to be used in direct
vehicle-to-vehicle communications, among several other possibilities.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
3GPP: Third Generation Partnership Project.
3G: Third Generation.
4G: Fourth Generation.
5G: Fifth Generation of mobile networks.
apps: applications.
AODV: Ad-hoc On-demand Distance Vector.
ARIB: Association of Radio Industries and Businesses.
BSS: Basic Service Set.
C-ACC: Cooperative Adaptive Cruise Control.
CAM: Cooperative Awareness Message.
CC: Cruise Control.
CEN: European Committee for Standardizatin (Comite europeen de
normalisation, fr.)
DeNM: Decentralized Environmental Notification Message.
DMM: Distributed Mobility Management.
Petrescu, et al. Expires October 20, 2016 [Page 4]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
DSRC: Dedicated Short Range Communications, as referenced in the
United States FCC Report and Order for the frequency allocation for
5.9GHz band in North America, which refers to "DSRC" as the ASTM
(earlier "American Society for Testing and Materials") standard
"E2213". Other interpretations of "DSRC" include the DSRC standard
developed in ISO TC204 WG17 and CEN TC278 which uses a different
frequency spectrum than the one used in North America.
E2E: end-to-end.
EMS: Emergency and Medical System providers.
EPC: Evolved Packet Core.
ETSI: European Telecommunications Standards Institute.
E-UTRAN: Evolved Universal Terrestrial Radio Access Network.
EU: European Union.
FAST: fast.
FCC: Federal Communications Commision.
FNTP: Fast Networking and Transport layer Protocol.
FSAP: Fast Service Advertisement Protocol.
I2V: Infrastructure to Vehicle.
ICT: Information and Communication Technologies.
IEEE: Institute of Electrical and Electronics Engineers.
IoT: Internet of Things.
IP: Internet Protocol.
IPv6: Internet Protocol version 6.
IPTV: Internet Protocol Television
ISO: International Organization for Standardization.
ITS: Intelligent Transportation Systems.
ITS-G5: ITS Gigahertz Five.
Petrescu, et al. Expires October 20, 2016 [Page 5]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
ITU: International Telecommunication Union.
ITU-T: Telecommunication Standardization Sector of the International
Telecommunication Union.
IVC-RVC:
LiFi: Light Fidelity.
LTE : Long-Term Evolution.
METIS: Mobile and wireless communications Enablers for Twenty-twenty
(2020) Information Society.
OBU: On-Board Unit.
OCB: Outside the Context of a BSS identifier.
PHY: physical layer.
ProSe: Proximity Service.
PSAP: Public Safety Answering Points.
RA: Router Advertisement.
SAE: Society of Automotive Engineers.
SDO: Standards Development Organization.
SG: Study Group.
TC: Technical Committee.
TR: Technical Report.
UE: User Equipment.
US: United States.
V2V: Vehicle-to-Vehicle communications.
V2X: Vehicle-to-'other' communications. E.g. Vehicle-to-
Infrastructure (V2I), Vehicle-to-Pedestrian (V2P), Vehicle-to-
Nomadic[device] (V2N), Vehicle-to-Device (V2D) and more.
V2I2V: Vehicle to Infrastructure to Vehicle.
Petrescu, et al. Expires October 20, 2016 [Page 6]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
WAVE: Wireless Access for Vehicular Environments.
WG1: Work Group 1.
WiFi: Wireless Fidelity.
WLAN: Wireless Local Area Network.
3. ETSI ITS C-ACC and Platooning use-case and reqs
ETSI Technical Committee Intelligent Transportation Systems (ETSI TC
ITS) is responsible for the development and maintenance of standards,
specifications and other reports on the implementation of V2V
communications in Cooperative ITS. Its scope extends from the
wireless access (excluding issues in radio frequency) to generic
services and corresponding applications. Security and tests
specifications are also covered. This responsibility is reflected in
the organization with five working groups that make up the committee.
Among them, WG1 is responsible of the facilities and applications
needs.
Under the EU Mandate M/453, TC ITS has developed a minimum set of
standards (Release 1) for systems interoperability during initial
deployment. The list of standards and specifications are provided in
the publicly available report ETSI TR 101 607. A second release of
the standards is being prepared. It should support more complex use
cases, possible integration with other technologies as well as a more
elaborate consideration of access networks other than the ITS-G5
(European profile of IEEE 802.11p). The TC ITS WG1 is currently
working on two separate work items for pre-standardization studies on
C-ACC (DTR/ITS-00164) and Platooning (DTR/ITS-00156). The scope of
the target technical reports is to describe the relevant use cases
that could be enabled by Cooperative ITS, to survey the existing
related standards and to identify what new features and standards are
needed to support these use cases.
The C-ACC definition in TR 103 299 will soon be made public.
4. The C-ACC Use of Protocols specified by IEEE 1609 Standards
The C-ACC interacts with the presentation layer services which in
turn use the communication protocols specified in IEEE 1609
standards.
One perspective from IEEE P1609 is that Cooperative Adaptive Cruise
Control (CACC) represents an "application". An application is
typically software whose communication needs are situated at the
upper layers of a communication stack - e.g. the Application Layer.
Petrescu, et al. Expires October 20, 2016 [Page 7]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
As such it is little relevant to IEEE P1609; P1609 is concerned more
with physical, data-link and network communication layers. On
another hand, a perspective well considered in IEEE P1609 is that
C-ACC and Platooning may be more relevant to the Society of
Automotive Engineers.
5. SAE perspective on C-ACC and Platooning
The Society of Automotive Engineers (SAE) concerns itself with data
exchanges and host system requirements for applications. The SAE
DSRC Technical Committee (DSRC: Dedicated Short-Range Communications)
is working on C-ACC within the Cooperative Vehicle Task Force. In
addition, the SAE On-Road Vehicle Automation Committee is working on
a use-case relevant to C-ACC towards realization of a reference
architecture.
In addition to C-ACC, SAE is completing performance requirements for
V2V Safety Communications to profile a probable US-mandated
implementation. The concept is that a vehicle would send a link-
layer message set (Basic Safety Message, plus path history and path
prediction extensions) to a host vehicle to enable the host vehicle
to use the transmitted information in a driver warning or alert
algorithm. Because it is used for safety, it is of paramount
importance that the messages are authenticated through a Security
Credential Management System.
The SAE DSRC TC activities are in cooperative agreement to ETSI ITS
WG1, as there are information exchanges between the two bodies
[SAE-V2V].
6. 3GPP and EU projects using LTE Device-to-Device concepts
6.1. 3GPP
The Proximity Service (ProSe) allows a UE to discover and communicate
with other UEs that are in proximity directly or with the network
assistance. This may also be called as Device-to-Device (D2D)
communication. ProSe is intended for purposes such as public
security, network offloading, etc [GPP-TR-22-803].
The ProSe Communication path could use E-UTRAN or WLAN. In the case
of WLAN, only ProSe-assisted WLAN direct communication (i.e. when
ProSe assists with connection establishment management and service
continuity) is considered [GPP-TS-22-278].
The work on ProSe is initiated in 3GPP Release 12. Some enhancements
are being added in Release 13, e.g. Restricted ProSe Discovery.
Some use cases are identified in [GPP-TR-22-803], but most of which
Petrescu, et al. Expires October 20, 2016 [Page 8]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
are intended for common mobile users, e.g. pedestrians, but not for
vehicles moving at high speed. The latency in ProSe communication
may be a problem for V2X.
ProSe does not support V2X communication until at least Release 14,
but it has some very good characteristics which makes it a good
candidate for V2X besides DSRC. ProSe communication does not have to
go through the EPC, which will significantly reduce the latency.
ProSe also supports group and broadcast communication by means of a
common communication path established between the UEs.
There are some efforts within 3GPP Release 14, trying to address V2X
communication. The efforts are proposed by experts in the industry,
and may be subject to change. These efforts include the following,
not an exhaustive list:
o To address the V2X use cases in 3GPP. Some use cases have been
defined by other SDOs, e.g. ETSI ITS; 3GPP can reference to them.
Requirements for V2X communication should also be considered, for
example network delay, packet loss rate, etc. [METIS-D1.1]
already propose some requirements, but those are intended for
future mobile network, which may be too critical for LTE.
o To address V2X applications and messages. The messages may
include message defined in SAE J2735, ETSI Cooperative Awareness
Message (CAM) and ETSI Decentralized Environmental Notification
Message (DeNM). The messages defined by different SDOs might be
similar to each other.
o Study of possibility to add enhancements to ProSe, and to make it
able to support and enhance DSRC.
o Study of using existing LTE technologies for unicast/multicast/
broadcast communication.
[GPP-TR-22-885] studies many V2X services using LTE. These services
include V2V communication (e.g. Cooperative Adaptive Cruise Control,
Forwarding Collision Warning, etc), V2I/V2N communication (e.g. Road
Safety Services) and vehicle to pedestrian communication. The
services' pre-condition, service flow, post-condition, including some
network communication requirements, such as delay, messages frequency
and message size, are ayalyzed.
In [GPP-TR-22-885], Cooperative Adaptive Cruise Control (CACC) allows
a vehicle to join a group of CACC vehicles; the benefits are to
improve road congestion and fuel efficiency. Member vehicles of CACC
group should periodically broadcast messages including the CACC group
information, such as speed and gap policies, etc. If a vehicle
Petrescu, et al. Expires October 20, 2016 [Page 9]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
outside the group wants to join, it should send a request to the
group. If a member of the CACC group accepts the request, it should
send a confirm message and provide necessary distance gap; and
members of the group will update their group information. When a
member wants to leave the CACC group, it broadcasts a goodbye
message, and the driver once again assumes control of the vehicle.
6.2. METIS
METIS is co-funded by the European Commission as an Integrated
Project under the Seventh Framework Programme for research and
development (FP7).
METIS defines test cases and requirements of "Traffic safety and
efficiency", as depicted in [METIS-D1.1], which is intended for 5G in
2020 but may also be applicable for LTE and subsequent systems.
The use cases include:
1. Dangerous situation that can be avoided by means of V2V
communications.
2. Dangerous situation with vulnerable road users (i.e. pedestrians,
cyclists,...) that can be avoided by means of V2D communications.
"D" can denote any cellular device that the vulnerable road user
may carry (e.g. smart phone, tablet, sensor tag).
3. Assistance services that can improve traffic efficiency by means
of V2X communications, e.g. traffic sign recognition and green
light assistance.
4. Autonomous platooning increase traffic flow and reduce fuel
consumption and emissions.
5. Automated vehicles.
To support the above use cases, METIS works out the corresponding
network requirements. For instance, for some applications the E2E
latency must be within 5ms; other requirements include data rates for
various scenarios, service ranges in highway/rural/urban scenarios,
etc.
7. ISO perspective on V2V
The International Standards Organization's Technical Committee 204
"Intelligent transport systems" (ISO TC204, in short) has specified a
communication architecture known as the "ITS station reference
communication architecture" [ISO-21217]. This communication
Petrescu, et al. Expires October 20, 2016 [Page 10]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
architecture covers all protocol stack layers (access technologies,
network, transport, facilities and applications). It is designed to
accommodate communications between ITS stations engaged in ITS
services. ITS stations can be deployed in vehicles of any type,
roadside infrastructure (traffic lights, variable message signs, toll
road gantries, etc.), urban infrastructure (parking gates, bus stops,
etc.) nomadic devices (smartphones, tablets) and control centers
(traffic control center, emergency call centers, data centers and
services centers). The ITS stations can be distributed in several
nodes (e.g. an in-vehicle gateway and a set of hosts attached to the
internal in-vehicle network). The ITS station architecture is
designed to support many kinds of wired and wireless access
technologies (vehicular WiFi 802.11p, urban WiFi 802.11b/g/n/ac/ad;
cellular networks; satellite; infra-red, LiFi, millimeter wave, etc.)
The ISO ITS station architecture can thus support both broadcast and
unicast types of communication, vehicle-to-infrastructure
communications (road infrastructure using e.g. WiFi, or cellular
infrastructure using e.g. 3G/4G) and, most notably, direct vehicle-
to-vehicle communications.
The architecture includes the possibility to communicate using IPv6
[ISO-21210] or non-IP (ISO FNTP, currently being harmonized with IEEE
WAVE).
The ISO TC204/WG14 (Work Group 14 "Vehicle/Roadway Warning and
Control Systems") is developing a draft of international standard for
C-ACC systems. The focus is on vehicular system control, rather than
on communication media. The potential work item is in an early stage
of development; it may describe performance requirements or
validation through test procedures. It is considered that "C-ACC" to
be an expansion to the existing ACC concepts which have been
previously described in the document ISO 15622 "Adaptive Cruise
Control Systems". The potential C-ACC work item may require the
specific involvement of Vehicle-to-Vehicle communications and other
types of communications (I2V and more), in addition to requiring
active sensing involving radars and camera systems.
8. ISO-IEEE Harmonization
The intent is to harmonize the IEEE 1609 and ISO FAST protocols at
5.9GHz to avoid having to support region-dependent protocols (e.g.
different protocols in Europe and the US), and this intention is not
dependent on any particular application or service.
The IEEE 1609.3 WG developed a version 3 draft of 1609.3 such that
after publication of this version 3, and after subsequent appropriate
updates of ISO 29281-1 and ISO 24102-5 an interoperability mode with
Petrescu, et al. Expires October 20, 2016 [Page 11]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
ISO 29281-1 v2 FNTP and ISO 24102-5 v2 FSAP will be given. This
interoperability in the first step will be limited to broadcast of
messages (e.g. for road safety) such that an ITS station unit can
properly receive messages sent out by a WAVE device, and vice versa.
C-ACC and Platooning are (C-)ITS services that will be deployed as
ITS applications on ITS stations in vehicles. These applications can
and will make use of ITS station communication services (network and
transport protocols, data link layer protocols, and physical layer
protocols) that have the necessary characteristics/properties (e.g.
V2V, low-latency, moderate bandwidth, etc.) to achieve their goals.
The IEEE 1609 and ISO protocols and communication services, whether
or not they are ultimately "harmonized", can be used by either or
both of these ITS applications as they generally meet the
requirements for these apps.
Some communication tasks in C-ACC and Platooning will use IPv6,
whereas others will not. For example some vendors of WAVE devices
and ITS station units consider the use of the short messages protocol
(not IPv6) for C-ACC and Platooning scenarios.
9. V2V communications at ITU
The International Telecommunication Union (ITU) is the United Nations
specialized agency for information and communication technologies.
It is an early standards development organization known for example,
among other things, for spectrum or stationary orbit allocations to
countries.
Within ITU, the Telecommunication Standardization Sector (ITU-T) is
composed of Study Groups (SGs) which make Recommendations which lead
to standards for countries' Information and Communication
Technologies (ICT) networks.
The ITU-T SG 16 leads ITU's standardization work on multimedia coding
and it is also the lead group for promissing topics such as the
Internet of Things activities (IoT), Internet Protocol Television
(IPTV) and Intelligent Transportation Systems (ITS).
The Question 27/16 of ITU-T SG 16 titled "Vehicle gateway platform
for telecommunication/ITS services/applications" is a group motivated
by the observation that, among others, the information generated by
vehicles has an important role in the chain of telecommunications and
ITS.
Currently under discussion, the proposed study items include the
definition of a gateway (aka OBU) and the functions and requirements
to support vehicle-to-vehicle and vehicle-to-intrastructure
Petrescu, et al. Expires October 20, 2016 [Page 12]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
tellecommunications. Another study item is to define scenarios for
such gateways acting as bridges (presumably "IP routers" , Ed.)
between cars and between cars and the infrastructure.
The description of ITU-T Question 27/16 is publicly available on the
web on the itu.int website.
10. ARIB and ITS Info-comm use of CACC and V2V concepts
In Japan, the Association of Radio Industries and Businesses (ARIB)
and the ITS Info-communications Forum produce standards and
guidelines for Intelligent Transportation Systems. Whereas US and EU
standards focus mainly on the 5.9GHz bands for ITS, the Japanese
standards operate initially in a 700MHz band.
The publicly and freely available document RC-013 version 1.0 titled
"Experimental Guideline for Inter-Vehicle Communication Messages"
considers that inter-vehicle communications (presumably V2V, Ed.) are
realized with Basic Messages. A Basic Message is generated by an
application layer running on top of a "IVC-RVC" layer (at the typical
network-layer place, Ed.) which runs itself on top of a Layer 2
"data-link" and of a Layer 1 PHY. The contents of a Basic Message
can be any one of the following: time information, position
information, vehicle status, and more. A particular data frame
representing status information is the
"DE_CooperativeAdaptiveCruiseControlStatus" represented on 2 bits.
11. FirstNet EMS use of LTE and IP in V2I2V
FirstNet is a corporation housed inside the US Department of
Commerce. It gets capitalization budget from, among other sources,
sale of spectrum by the US FCC. It gets operating budget from sale
of services to state emergency services entities.
The communications architectures for FirstNet include vehicle-to-
vehicle, vehicle-to-infrastructure and vehicle-to-infrastructure-to-
vehicle communications using, in certain cases, LTE and IP:
o Emergency communications to vehicles from government entities
conveying, for example: weather warnings, road conditions,
evacuation orders. The government entities might include PSAPs or
mobile vehicles such as police cruisers.
o Instrumented emergency services vehicles such as ambulances. An
example is the ability to telemeter casualty (patient) data from
sensors attached to the casualty to a hospital emergency room.
Petrescu, et al. Expires October 20, 2016 [Page 13]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
o Emergency communications from vehicles' occupants to government
entities such as Public Safety Access Points (PSAPs, also known as
911 operators in US).
The National Public Safety Telecommunications Council describes
FirstNet as an emergency communications system (largely viewed
through the prism of the familiar Land Mobile Radio systems most
emergency services use.) The cellular telephone industry views
FirstNet as supplementary to an existing commercial cellphone system
(e.g. reusing the same towers and backhaul). Perhaps a better view
of FirstNet is as an extension of the Internet to emergency services
vehicles (including pedestrian).
It is clear that FirstNet overlaps with a large extent to the
concepts that have been discussed in vehicle-to-vehicle
communications for other purposes.
FirstNet has not been clear about its communication technology
choices to date. But LTE has been discussed as the most likely layer
2 protocol. A segregated segment of spectrum in the 700MHz band has
been set aside by Congressional action for emergency services and
control of that spectrum has been passed to FirstNet. There appear
to be no new protocols developed by FirstNet. Several Internet
applications would need rework to handle high availability, security
and assured access needs of emergency services.
12. Internet apps: WAZE, iRezQ, Coyote, Sentinel
Applications using the Internet have been developed in the particular
context of vehicular communications. These applications are designed
for parties situated in vehicles. Their profile is less of client-
server kind, but more of peer-to-peer kind (vehicle to vehicle).
Some use vehicle-to-infrastructure-to-vehicle IP paths, whereas
others involve direct vehicle-to-vehicle paths (without
infrastructure).
These applications are described in more detail in a recent Internet
Draft titled "Scenario of Intelligent Transportation System"
[I-D.liu-its-scenario].
13. Car manufacturer labels with V2V features
Toyota "ITS Connect" is a feature advertised for high-end automobile
models set to hit the roads by the end of 2015. This includes the
Crown as well as two other lower level models. The "ITS Connect"
features which exhibit V2V characteristics are Right Turn Collision
Caution, Red Light Caution and Emergency Vehicle Proximity
Petrescu, et al. Expires October 20, 2016 [Page 14]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
Notification. One particular V2V feature which illustrates a
possible migration from exclusively radar signals to bidirectional
data exchanges is the Communicating Radar Cruise Control. A publicly
available description of this feature mentions that it integrates
Radar Cruise Control and V2V information from the preceding vehicle
to help follow it smoothly. Toyota "ITS Connect" is using Japanese
ARIB standards STD-Txxx and ITS Info-communications Forum Guidelines
RC-xxx in the 700MHz band.
14. Gap Analysis
It is generally agreed that one or more IP subnets are embedded in an
automobile. The embedded network is formed by at least two (and
generally up to 5) distinct IP subnets. In each of the subnets
several IP-addressable computers are currently enabled with IP
stacks.
The realization of V2V communications can happen by connecting
together two such embedded networks, each carried by a distinct
vehicle. With a direct connection, an IP Router in one vehicle
connects to an IP Router in another vehicle nearby. The maximum
distance between two such vehicles is dictated by the link layer
technology (e.g., with IEEE 802.11p OCB mode the distance may be up
to 800 metres). On another hand, an indirect connection may involve
the use of a Road-Side Unit, or a longer IP path through a cellular
network. It is expected that the shortest latencies to be obtained
with the most straightforward (direct) connections rather than
through-fixed-RSU through-cellular.
When two vehicles are connected to each other in this way, an IP
subnet is formed between the egress interfaces of Router embedded in
vehicles. There are several ways in which the IP path can be
established across this 1-hop subnet.
14.1. Neighbor Discovery protocol
Routers exchange Router Advertisement messages. An RA message
contains prefixes announced to be valid on one link. On another
hand, the prefix announced by an RA can not be equal to the prefix of
a same router but of one of its other interfaces. And this
represents a shortcoming of the ND protocol - it can not support V2V
topologies.
14.2. Mobile IP protocol
There are two modes of operation of a V2V topology. With a link
technology like IEEE 802.11b it is possible that one vehicle attaches
to another vehicle in "Access Point" mode, or alternatively in "ad-
Petrescu, et al. Expires October 20, 2016 [Page 15]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
hoc" mode. In "Access Point" mode (or Client-Server), the first
vehicle allocates an address, and potentially a prefix, to the second
vehicle. This latter may then use the Mobile IP protocol to inform
the first vehicle about in-car prefix (use a Binding Update message
as if the Access Point vehicle were a Correspondent Node). The gap
is in that currently the Mobile IP protocol is not fully specified to
send BUs in that way.
This Mobile IP gap depends largely on the situation (physical
location) of the Home Agent entity. The placement of the Home Agent
in the fixed infrastructure is assumed by the most common deployments
of connected vehicles. The Home Agent in charge of the vehicle is
situated in a data center owned and administered by the vehicle
manufacturer. Other similar placements consider the fixed network of
a regional representative of the manufacturer, or a local dealer.
Further, in theory, it can be considered that a Home Agent be placed
inside a vehicle as well, although this has not been tested.
Depending on this placement of the HA, the Mobile IP gap can vary.
Note a new requirement has been developped recently in the DMM
Working Group. The distributed mobility management requirement REQ1
in [RFC7333] states that DMM solutions must enable traffic to avoid
traversing a single mobility anchor far from the optimal route. This
may help placing a Home Agent nearer to the access network (rather
than in a data center). In addition to this requirement, it may be
necessary to dynamically migrate the Home Agent to a place near the
vehicle, as it moves across borders or travel long distances.
14.3. AODVv2 protocol
The AODVv2 protocol [I-D.ietf-manet-aodvv2] is a routing protocol
used to build and find IP paths in an ad hoc network. However,
AODVv2 does not take into account preconfiguration of default routes.
Default routes are extensively used in current networks carried in
vehicles. Good administration of default routes can greatly simplify
routing in such networks. This represents a gap.
15. Security Considerations
All government-to-vehicle and vehicle-to-government communications,
without exception, require authentication.
Some, but not all, communications from government-to-vehicle and
vehicle-to-government require confidentiality to protect the content
of the messages. Some of these requirements, such as medical data,
have the force of law. Others are customary, or are based on common
respect as requirements.
Petrescu, et al. Expires October 20, 2016 [Page 16]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
Protocol information shared between the cooperating vehicles MUST
also be protected in order to avoid disruption or attack on the
vehicles operation. Any modification or malicious insertion of
protocol messages would carry with it a high risk of death and injury
as well as tremendous disruption of other vehicular traffic.
16. IANA Considerations
mandatory
17. Contributors
Jim Misener (Qualcomm, SAE DSRC TC Chair), Masanori Misumi (Mazda,
ISO TC204/WG14 Convenor), Michelle Wetterwald (Consult Europe), Tom
Kurihara (mindspring).
18. References
18.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J.
Korhonen, "Requirements for Distributed Mobility
Management", RFC 7333, DOI 10.17487/RFC7333, August 2014,
<http://www.rfc-editor.org/info/rfc7333>.
18.2. Informative References
[ACC-def] Liang, C-Y. and H. Peng, "Optimal Adaptive Cruise Control
with Guaranteed String Stability", April 1999.
[CACC-def]
Shladover, E., Nowakowski, C., Lu, X-Y., and X-Y. Ferlis,
"Cooperative Adaptive Cruise Control (CACC) Definitions
and Operating Concepts", April 2015.
[ETSI-CACC]
ETSI Technical Report TR 103 299, "Cooperative Adaptive
Cruise Control (C-ACC) prestandardization study (ETSI-SAE
join WI proposal); ongoing at the time of writing of this
Internet Draft", 2015.
Petrescu, et al. Expires October 20, 2016 [Page 17]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
[GPP-TR-22-803]
3GPP, "Feasibility study for Proximity Services (ProSe)",
June 2013.
[GPP-TR-22-885]
3GPP, "Study on LTE Support for V2X Services", April 2015.
[GPP-TS-22-278]
3GPP, "Service requirements for the Evolved Packet System
(EPS)", December 2014.
[I-D.ietf-manet-aodvv2]
Perkins, C., Ratliff, S., Dowdell, J., Steenbrink, L., and
V. Mercieca, "Ad Hoc On-demand Distance Vector Version 2
(AODVv2) Routing", draft-ietf-manet-aodvv2-14 (work in
progress), April 2016.
[I-D.liu-its-scenario]
Liu, D., "Scenario of Intelligent Transportation System",
draft-liu-its-scenario-00 (work in progress), March 2015.
[I-D.petrescu-ipv6-over-80211p]
Petrescu, A., Benamar, N., and T. Leinmueller,
"Transmission of IPv6 Packets over IEEE 802.11 Networks
Outside the Context of a Basic Service Set", draft-
petrescu-ipv6-over-80211p-03 (work in progress), October
2015.
[ISO-21210]
ISO, "21210: TC ITS - WG CALM - IPv6 Networking -
International Standard", 2014.
[ISO-21217]
ISO, "21217: TC ITS - WG CALM - Architecture -
International Standard", 2014.
[ISO-CACC]
ISO, "PWI 20035 Intelligent Transport Systems -
Cooperative Adaptive Cruise Control Systems (CACC) -
Performance requirements and test procedures, Reference
number 20035; ongoing work at the time of writing of this
Internet Draft.", 2015.
[its-infocomm-CACC]
ITS Info-communications Forum of Japan, "Experimental
Guideline for Inter-vehicle Communication Messages; ITS
Forum RC-013 Ver. 1.0", 2014.
Petrescu, et al. Expires October 20, 2016 [Page 18]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
[ITU-V2V] ITU, "Question 27/16 - Vehicle gateway platform for
telecommunications/ITS services/applications; ongoing work
at the time of writing this Internet Draft.", 2015.
[METIS-D1.1]
Fallgren, M. and B. Timus, "Scenarios, requirements and
KPIs for 5G mobile and wireless system", April 2013.
[SAE-V2V] SAE International (Society for Automotive Engineering),
J2945/1; ongoing work at the time of writing this Internet
Draft., "On-board System Requirements for V2V Safety
Communications", 2015.
Appendix A. ChangeLog
The changes are listed in reverse chronological order, most recent
changes appearing at the top of the list.
From -04 to -05:
o Minor updates.
From -03 to -04:
o Updated the perspective from SAE with respect to work on V2V
requirements for safety.
o Clarified the IEEE 1609 point of view by which C-ACC use IEEE 1609
protocols.
o Added authors' point of view of IEEE-ISO harmonization, which may
have a relationship to vehicle-to-vehicle communications.
o Added ITU-T Question 27 of Study Group 16 description mentioning
V2V communications.
o Added a section on Japan's ARIB and ITS info-comm documents which
describe C-ACC and other inter-vehicle services in the 700MHz
band. Added an example of car manufacturer with product on the
market at the time of writing implementing some of these features.
o Clarification of HA placement conditioning the Mobile IP gap
discussion.
o Editorial improvements, citations added, terminology section
improved.
From -01 to -02:
Petrescu, et al. Expires October 20, 2016 [Page 19]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
o Added perspectives on C-ACC and Platooning from ETSI, SAE, and
IEEE P1609. Updated the perspective from ISO.
o Added Gap Analysis: what are the gaps between what existing
protocols ND, Mobile IP and AODV can do and what is needed to
realize a C-ACC and Platooning use-case with a V2V topology?
Authors' Addresses
Alexandre Petrescu (editor)
CEA, LIST
CEA Saclay
Gif-sur-Yvette , Ile-de-France 91190
France
Phone: +33169089223
Email: Alexandre.Petrescu@cea.fr
James Huang
Huawei Technologies
Shenzhen
China
Email: james.huang@huawei.com
Thierry Ernst
Mines ParisTech
Paris 75006
France
Email: Thierry.Ernst@mines-paristech.fr
Rex Buddenberg
Retired
US
Email: buddenbergr@gmail.com
Petrescu, et al. Expires October 20, 2016 [Page 20]
Internet-Draft C-ACC at SDOs and IP Gap Analysis April 2016
Charles E. Perkins
Futurewei Inc.
2330 Central Expressway
Santa Clara, CA 95050
USA
Phone: +1-408-330-4586
Email: charliep@computer.org
Petrescu, et al. Expires October 20, 2016 [Page 21]
