draft-ietf-ipwave-vehicular-networking-14.txt   draft-ietf-ipwave-vehicular-networking-15.txt 
IPWAVE Working Group J. Jeong, Ed. IPWAVE Working Group J. Jeong, Ed.
Internet-Draft Sungkyunkwan University Internet-Draft Sungkyunkwan University
Intended status: Informational March 9, 2020 Intended status: Informational June 29, 2020
Expires: September 10, 2020 Expires: December 31, 2020
IPv6 Wireless Access in Vehicular Environments (IPWAVE): Problem IPv6 Wireless Access in Vehicular Environments (IPWAVE): Problem
Statement and Use Cases Statement and Use Cases
draft-ietf-ipwave-vehicular-networking-14 draft-ietf-ipwave-vehicular-networking-15
Abstract Abstract
This document discusses the problem statement and use cases of This document discusses the problem statement and use cases of
IPv6-based vehicular networking for Intelligent Transportation IPv6-based vehicular networking for Intelligent Transportation
Systems (ITS). The main scenarios of vehicular communications are Systems (ITS). The main scenarios of vehicular communications are
vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and
vehicle-to-everything (V2X) communications. First, this document vehicle-to-everything (V2X) communications. First, this document
explains use cases using V2V, V2I, and V2X networking. Next, it explains use cases using V2V, V2I, and V2X networking. Next, for
makes a problem statement about key aspects in IPv6-based vehicular IPv6-based vehicular networks, it makes a gap analysis of current
networking, such as IPv6 Neighbor Discovery, Mobility Management, and IPv6 protocols (e.g., IPv6 Neighbor Discovery, Mobility Management,
Security & Privacy. For each key aspect, this document specifies and Security & Privacy), and then lists up requirements for the
requirements for IPv6-based vehicular networking. extensions of those IPv6 protocols for IPv6-based vehicular
networking.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 10, 2020. This Internet-Draft will expire on December 31, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 17 skipping to change at page 2, line 18
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. V2V . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1. V2V . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2. V2I . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2. V2I . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3. V2X . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.3. V2X . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4. Vehicular Networks . . . . . . . . . . . . . . . . . . . . . 11 4. Vehicular Networks . . . . . . . . . . . . . . . . . . . . . 11
4.1. Vehicular Network Architecture . . . . . . . . . . . . . 11 4.1. Vehicular Network Architecture . . . . . . . . . . . . . 11
4.2. V2I-based Internetworking . . . . . . . . . . . . . . . . 14 4.2. V2I-based Internetworking . . . . . . . . . . . . . . . . 16
4.3. V2V-based Internetworking . . . . . . . . . . . . . . . . 16 4.3. V2V-based Internetworking . . . . . . . . . . . . . . . . 18
5. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 17 5. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 20
5.1. Neighbor Discovery . . . . . . . . . . . . . . . . . . . 17 5.1. Neighbor Discovery . . . . . . . . . . . . . . . . . . . 21
5.1.1. Link Model . . . . . . . . . . . . . . . . . . . . . 19 5.1.1. Link Model . . . . . . . . . . . . . . . . . . . . . 22
5.1.2. MAC Address Pseudonym . . . . . . . . . . . . . . . . 20 5.1.2. MAC Address Pseudonym . . . . . . . . . . . . . . . . 24
5.1.3. Routing . . . . . . . . . . . . . . . . . . . . . . . 21 5.1.3. Routing . . . . . . . . . . . . . . . . . . . . . . . 25
5.2. Mobility Management . . . . . . . . . . . . . . . . . . . 21 5.2. Mobility Management . . . . . . . . . . . . . . . . . . . 25
6. Security Considerations . . . . . . . . . . . . . . . . . . . 22 6. Security Considerations . . . . . . . . . . . . . . . . . . . 26
7. Informative References . . . . . . . . . . . . . . . . . . . 24 7. Informative References . . . . . . . . . . . . . . . . . . . 29
Appendix A. Changes from draft-ietf-ipwave-vehicular- Appendix A. Changes from draft-ietf-ipwave-vehicular-
networking-13 . . . . . . . . . . . . . . . . . . . 29 networking-14 . . . . . . . . . . . . . . . . . . . 36
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 29 Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 36
Appendix C. Contributors . . . . . . . . . . . . . . . . . . . . 30 Appendix C. Contributors . . . . . . . . . . . . . . . . . . . . 36
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 32 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction 1. Introduction
Vehicular networking studies have mainly focused on improving safety Vehicular networking studies have mainly focused on improving safety
and efficiency, and also enabling entertainment in vehicular and efficiency, and also enabling entertainment in vehicular
networks. The Federal Communications Commission (FCC) in the US networks. The Federal Communications Commission (FCC) in the US
allocated wireless channels for Dedicated Short-Range Communications allocated wireless channels for Dedicated Short-Range Communications
(DSRC) [DSRC] in the Intelligent Transportation Systems (ITS) with (DSRC) [DSRC] in the Intelligent Transportation Systems (ITS) with
the frequency band of 5.850 - 5.925 GHz (i.e., 5.9 GHz band). DSRC- the frequency band of 5.850 - 5.925 GHz (i.e., 5.9 GHz band). DSRC-
based wireless communications can support vehicle-to-vehicle (V2V), based wireless communications can support vehicle-to-vehicle (V2V),
vehicle-to-infrastructure (V2I), and vehicle-to-everything (V2X) vehicle-to-infrastructure (V2I), and vehicle-to-everything (V2X)
networking. The European Union (EU) allocated radio spectrum for networking. The European Union (EU) allocated radio spectrum for
safety-related and non-safety-related applications of ITS with the safety-related and non-safety-related applications of ITS with the
frequency band of 5.875 - 5.905 GHz, as part of the Commission frequency band of 5.875 - 5.905 GHz, as part of the Commission
Decision 2008/671/EC [EU-2008-671-EC]. Decision 2008/671/EC [EU-2008-671-EC].
For direct inter-vehicular wireless connectivity, IEEE has amended For direct inter-vehicular wireless connectivity, IEEE has amended
WiFi standard 802.11 to enable driving safety services based on DSRC standard 802.11 (commonly known as Wi-Fi) to enable safe driving
for the Wireless Access in Vehicular Environments (WAVE) system. The services based on DSRC for the Wireless Access in Vehicular
Physical Layer (L1) and Data Link Layer (L2) issues are addressed in Environments (WAVE) system. The Physical Layer (L1) and Data Link
IEEE 802.11p [IEEE-802.11p] for the PHY and MAC of the DSRC, while Layer (L2) issues are addressed in IEEE 802.11p [IEEE-802.11p] for
IEEE 1609.2 [WAVE-1609.2] covers security aspects, IEEE 1609.3 the PHY and MAC of the DSRC, while IEEE 1609.2 [WAVE-1609.2] covers
[WAVE-1609.3] defines related services at network and transport security aspects, IEEE 1609.3 [WAVE-1609.3] defines related services
layers, and IEEE 1609.4 [WAVE-1609.4] specifies the multi-channel at network and transport layers, and IEEE 1609.4 [WAVE-1609.4]
operation. IEEE 802.11p was first a separate amendment, but was specifies the multi-channel operation. IEEE 802.11p was first a
later rolled into the base 802.11 standard (IEEE 802.11-2012) as IEEE separate amendment, but was later rolled into the base 802.11
802.11 Outside the Context of a Basic Service Set (OCB) in 2012 standard (IEEE 802.11-2012) as IEEE 802.11 Outside the Context of a
[IEEE-802.11-OCB]. Basic Service Set (OCB) in 2012 [IEEE-802.11-OCB].
Along with these WAVE standards, IPv6 [RFC8200] and Mobile IPv6 3GPP has standardized Cellular Vehicle-to-Everything (C-V2X)
protocols (e.g., Mobile IPv6 (MIPv6) [RFC6275], and Proxy MIPv6 communications to support V2X in LTE mobile networks (called LTE V2X)
(PMIPv6) [RFC5213]) can be applied to vehicular networks. In and V2X in 5G mobile networks (called 5G V2X) [TS-23.285-3GPP]
addition, ISO has approved a standard specifying the IPv6 network [TR-22.886-3GPP][TS-23.287-3GPP]. With C-V2X, vehicles can directly
protocols and services to be used for Communications Access for Land communicate with each other without relay nodes (e.g., eNodeB in LTE
Mobiles (CALM) [ISO-ITS-IPv6]. and gNodeB in 5G).
Along with these WAVE standards and C-V2X standards, regardless of a
wireless access technology under the IP stack of a vehicle, vehicular
networks can operate IP mobility with IPv6 [RFC8200] and Mobile IPv6
protocols (e.g., Mobile IPv6 (MIPv6) [RFC6275], Proxy MIPv6 (PMIPv6)
[RFC5213], Distributed Mobility Management (DMM) [RFC7333], Locator/
ID Separation Protocol (LISP) [RFC6830], and Asymmetric Extended
Route Optimization (AERO) [RFC6706]). In addition, ISO has approved
a standard specifying the IPv6 network protocols and services to be
used for Communications Access for Land Mobiles (CALM) [ISO-ITS-IPv6]
[ISO-ITS-IPv6-AMD1].
This document describes use cases and a problem statement about This document describes use cases and a problem statement about
IPv6-based vehicular networking for ITS, which is named IPv6 Wireless IPv6-based vehicular networking for ITS, which is named IPv6 Wireless
Access in Vehicular Environments (IPWAVE). First, it introduces the Access in Vehicular Environments (IPWAVE). First, it introduces the
use cases for using V2V, V2I, and V2X networking in ITS. Next, it use cases for using V2V, V2I, and V2X networking in ITS. Next, for
makes a problem statement about key aspects in IPWAVE, namely, IPv6 IPv6-based vehicular networks, it makes a gap analysis of current
Neighbor Discovery (ND), Mobility Management (MM), and Security & IPv6 protocols (e.g., IPv6 Neighbor Discovery, Mobility Management,
Privacy (SP). For each key aspect of the problem statement, this and Security & Privacy), and then lists up requirements for the
document specifies requirements for IPv6-based vehicular networking. extensions of those IPv6 protocols, which are tailored to IPv6-based
This document is intended to motivate development of key protocols vehicular networking. Thus, this document is intended to motivate
for IPWAVE. development of key protocols for IPWAVE.
2. Terminology 2. Terminology
This document uses the terminology described in [RFC8691]. In This document uses the terminology described in [RFC8691]. In
addition, the following terms are defined below: addition, the following terms are defined below:
o Class-Based Safety Plan: A vehicle can make safety plan by o Class-Based Safety Plan: A vehicle can make a safety plan by
classifying the surrounding vehicles into different groups for classifying the surrounding vehicles into different groups for
safety purposes according to the geometrical relationship among safety purposes according to the geometrical relationship among
them. The vehicle groups can be classified as Line-of-Sight them. The vehicle groups can be classified as Line-of-Sight
Unsafe, Non-Line-of-Sight Unsafe, and Safe groups [CASD]. Unsafe, Non-Line-of-Sight Unsafe, and Safe groups [CASD].
o Context-Awareness: A vehicle can be aware of spatial-temporal o Context-Awareness: A vehicle can be aware of spatial-temporal
mobility information (e.g., position, speed, direction, and mobility information (e.g., position, speed, direction, and
acceleration/deceleration) of surrounding vehicles for both safety acceleration/deceleration) of surrounding vehicles for both safety
and non-safety uses through sensing or communication [CASD]. and non-safety uses through sensing or communication [CASD].
o DMM: "Distributed Mobility Management" [RFC7333][RFC7429]. o DMM: "Distributed Mobility Management" [RFC7333][RFC7429].
o Edge Computing (EC): It is the local computing near an access o Edge Computing (EC): It is the local computing near an access
network (i.e., edge network) for the sake of vehicles and network (i.e., edge network) for the sake of vehicles and
pedestrians. pedestrians.
o Edge Computing Device (ECD): It is a computing device (or server) o Edge Computing Device (ECD): It is a computing device (or server)
for edge computing for the sake of vehicles and pedestrians. for edge computing for the sake of vehicles and pedestrians.
o Edge Network (EN): In is an access network that has an IP-RSU for o Edge Network (EN): It is an access network that has an IP-RSU for
wireless communication with other vehicles having an IP-OBU and wireless communication with other vehicles having an IP-OBU and
wired communication with other network devices (e.g., routers, IP- wired communication with other network devices (e.g., routers, IP-
RSUs, ECDs, servers, and MA). It may have a radio receiver of RSUs, ECDs, servers, and MA). It may have a Global Positioning
Global Positioning System (GPS) for its position recognition and System (GPS) radio receiver for its position recognition and the
the localization service for the sake of vehicles. localization service for the sake of vehicles.
o IP-OBU: "Internet Protocol On-Board Unit": An IP-OBU denotes a o IP-OBU: "Internet Protocol On-Board Unit": An IP-OBU denotes a
computer situated in a vehicle such as a car, bicycle, or similar. computer situated in a vehicle (e.g., car, bicycle, autobike,
It has at least one IP interface that runs in mode OCB of 802.11 motor cycle, and a similar one) and a device (e.g., smartphone and
and has an "OBU" transceiver. Also, it may have an IP interface IoT device). It has at least one IP interface that runs in IEEE
that runs in Cellular V2X (C-V2X) [TS-23.285-3GPP]. See the 802.11-OCB and has an "OBU" transceiver. Also, it may have an IP
definition of the term "OBU" in [RFC8691]. interface that runs in Cellular V2X (C-V2X) [TS-23.285-3GPP]
[TR-22.886-3GPP][TS-23.287-3GPP]. See the definition of the term
"OBU" in [RFC8691].
o IP-RSU: "IP Roadside Unit": An IP-RSU is situated along the road. o IP-RSU: "IP Roadside Unit": An IP-RSU is situated along the road.
It has at least two distinct IP-enabled interfaces. The wireless It has at least two distinct IP-enabled interfaces. The wireless
PHY/MAC layer of at least one of its IP-enabled interfaces is PHY/MAC layer of at least one of its IP-enabled interfaces is
configured to operate in 802.11-OCB mode. An IP-RSU communicates configured to operate in 802.11-OCB mode. An IP-RSU communicates
with the IP-OBU over an 802.11 wireless link operating in OCB with the IP-OBU over an 802.11 wireless link operating in OCB
mode. Also, it may have an IP interface that runs in C-V2X along mode. Also, it may have an IP interface that runs in C-V2X along
with an "RSU" transceiver. An IP-RSU is similar to an Access with an "RSU" transceiver. An IP-RSU is similar to an Access
Network Router (ANR), defined in [RFC3753], and a Wireless Network Router (ANR), defined in [RFC3753], and a Wireless
Termination Point (WTP), defined in [RFC5415]. See the definition Termination Point (WTP), defined in [RFC5415]. See the definition
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mode of operation in which a Station (STA) is not a member of a mode of operation in which a Station (STA) is not a member of a
BSS and does not utilize IEEE Std 802.11 authentication, BSS and does not utilize IEEE Std 802.11 authentication,
association, or data confidentiality [IEEE-802.11-OCB]. association, or data confidentiality [IEEE-802.11-OCB].
o 802.11-OCB: It refers to the mode specified in IEEE Std o 802.11-OCB: It refers to the mode specified in IEEE Std
802.11-2016 [IEEE-802.11-OCB] when the MIB attribute 802.11-2016 [IEEE-802.11-OCB] when the MIB attribute
dot11OCBActivited is 'true'. dot11OCBActivited is 'true'.
o Platooning: Moving vehicles can be grouped together to reduce air- o Platooning: Moving vehicles can be grouped together to reduce air-
resistance for energy efficiency and reduce the number of drivers resistance for energy efficiency and reduce the number of drivers
such that only the leading vehicle has a driver and the other such that only the leading vehicle has a driver, and the other
vehicles are autonomous vehicles without a driver and closely vehicles are autonomous vehicles without a driver and closely
following the leading vehicle [Truck-Platooning]. follow the leading vehicle [Truck-Platooning].
o Traffic Control Center (TCC): A node that maintains road o Traffic Control Center (TCC): A system that manages road
infrastructure information (e.g., IP-RSUs, traffic signals, and infrastructure nodes (e.g., IP-RSUs, MAs, traffic signals, and
loop detectors), vehicular traffic statistics (e.g., average loop detectors), and also maintains vehicular traffic statistics
vehicle speed and vehicle inter-arrival time per road segment), (e.g., average vehicle speed and vehicle inter-arrival time per
and vehicle information (e.g., a vehicle's identifier, position, road segment) and vehicle information (e.g., a vehicle's
direction, speed, and trajectory as a navigation path). TCC is identifier, position, direction, speed, and trajectory as a
included in a vehicular cloud for vehicular networks. navigation path). TCC is part of a vehicular cloud for vehicular
networks.
o Vehicle: A Vehicle in this document is a node that has an IP-OBU o Vehicle: A Vehicle in this document is a node that has an IP-OBU
for wireless communication with other vehicles and IP-RSUs. It for wireless communication with other vehicles and IP-RSUs. It
has a radio navigation receiver of Global Positioning System (GPS) has a GPS radio navigation receiver for efficient navigation. Any
for efficient navigation. device having an IP-OBU and a GPS receiver (e.g., smartphone and
table PC) can be regarded as a vehicle in this document.
o Vehicular Ad Hoc Network (VANET): A network that consists of o Vehicular Ad Hoc Network (VANET): A network that consists of
vehicles interconnected by wireless communication. Two vehicles vehicles interconnected by wireless communication. Two vehicles
in a VANET can communicate with each other using other vehicles as in a VANET can communicate with each other using other vehicles as
relays even where they are out of one-hop wireless communication relays even where they are out of one-hop wireless communication
range. range.
o Vehicular Cloud: A cloud infrastructure for vehicular networks, o Vehicular Cloud: A cloud infrastructure for vehicular networks,
having compute nodes, storage nodes, and network forwarding having compute nodes, storage nodes, and network forwarding
elements (e.g., switch and router). elements (e.g., switch and router).
o Vehicle Detection Loop (i.e., Loop Detector): An inductive device
used for detecting vehicles passing or arriving at a certain
point, for instance, at an intersection with traffic lights or at
a ramp toward a highway. The relatively crude nature of the
loop's structure means that only metal masses above a certain size
are capable of triggering the detection.
o V2D: "Vehicle to Device". It is the wireless communication o V2D: "Vehicle to Device". It is the wireless communication
between a vehicle and a device (e.g., IoT device). between a vehicle and a device (e.g., smartphone and IoT device).
o V2P: "Vehicle to Pedestrian". It is the wireless communication
between a vehicle and a pedestrian's mobile device (e.g.,
smartphone).
o V2I2P: "Vehicle to Infrastructure to Pedestrian". It is the o V2I2D: "Vehicle to Infrastructure to Device". It is the wireless
wireless communication between a vehicle and a pedestrian's mobile communication between a vehicle and a device (e.g., smartphone and
device (e.g., smartphone) via an infrastructure node (e.g., IP- IoT device) via an infrastructure node (e.g., IP-RSU).
RSU).
o V2I2V: "Vehicle to Infrastructure to Vehicle". It is the wireless o V2I2V: "Vehicle to Infrastructure to Vehicle". It is the wireless
communication between a vehicle and another vehicle via an communication between a vehicle and another vehicle via an
infrastructure node (e.g., IP-RSU). infrastructure node (e.g., IP-RSU).
o V2I2X: "Vehicle to Infrastructure to Everything". It is the
wireless communication between a vehicle and another entity (e.g.,
vehicle, smartphone, and IoT device) via an infrastructure node
(e.g., IP-RSU).
o V2X: "Vehicle to Everything". It is the wireless communication
between a vehicle and any entity (e.g., vehicle, infrastructure
node, smartphone, and IoT device), including V2V, V2I, and V2D.
o VIP: "Vehicular Internet Protocol". It is an IPv6 extension for o VIP: "Vehicular Internet Protocol". It is an IPv6 extension for
vehicular networks including V2V, V2I, and V2X. vehicular networks including V2V, V2I, and V2X.
o VMM: "Vehicular Mobility Management". It is an IPv6-based o VMM: "Vehicular Mobility Management". It is an IPv6-based
mobility management for vehicular networks. mobility management for vehicular networks.
o VND: "Vehicular Neighbor Discovery". It is an IPv6 ND extension o VND: "Vehicular Neighbor Discovery". It is an IPv6 ND extension
for vehicular networks. for vehicular networks.
o VSP: "Vehicular Security and Privacy". It is an IPv6-based o VSP: "Vehicular Security and Privacy". It is an IPv6-based
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o WAVE: "Wireless Access in Vehicular Environments" [WAVE-1609.0]. o WAVE: "Wireless Access in Vehicular Environments" [WAVE-1609.0].
3. Use Cases 3. Use Cases
This section explains use cases of V2V, V2I, and V2X networking. The This section explains use cases of V2V, V2I, and V2X networking. The
use cases of the V2X networking exclude the ones of the V2V and V2I use cases of the V2X networking exclude the ones of the V2V and V2I
networking, but include Vehicle-to-Pedestrian (V2P) and Vehicle-to- networking, but include Vehicle-to-Pedestrian (V2P) and Vehicle-to-
Device (V2D). Device (V2D).
Since IP is widely used among various computing devices in the IP is widely used among popular end-user devices (e.g., smartphone
Internet, it is expected that the use cases in this section need to and tablet) in the Internet. Applications (e.g., navigator
work on top of IPv6 as the network layer protocol. Thus, the IPv6 application) for those devices can be extended such that the V2V use
for these use cases should be extended for vehicular IPv6 such that cases in this section can work with IPv6 as a network layer protocol
the IPv6 can support the functions of the network layer protocol such and IEEE 802.11-OCB as a link layer protocol. In addition, IPv6
as Vehicular Neighbor Discovery (VND), Vehicular Mobility Management security needs to be extended to support those V2V use cases in a
(VMM), and Vehicular Security and Privacy (VSP) in vehicular safe, secure, privacy-preserving way.
networks. Note that the adjective "Vehicular" in this document is
used to represent extensions of existing protocols such as IPv6 The use cases presented in this section serve as the description and
Neighbor Discovery, IPv6 Mobility Management (e.g., PMIPv6 [RFC5213] motivation for the need to extend IPv6 and its protocols to
and DMM [RFC7429]), and IPv6 Security and Privacy Mechanisms rather facilitate "Vehicular IPv6". Section 5 summarizes the overall
than new "vehicular-specific" functions. Refer to Section 5 for the problem statement and IPv6 requirements. Note that the adjective
problem statement of the requirements of the vehicular IPv6. "Vehicular" in this document is used to represent extensions of
existing protocols such as IPv6 Neighbor Discovery, IPv6 Mobility
Management (e.g., PMIPv6 [RFC5213] and DMM [RFC7429]), and IPv6
Security and Privacy Mechanisms rather than new "vehicular-specific"
functions. Refer to Section 5 for the problem statement of the
requirements of vehicular IPv6.
3.1. V2V 3.1. V2V
The use cases of V2V networking discussed in this section include The use cases of V2V networking discussed in this section include
o Context-aware navigation for driving safety and collision o Context-aware navigation for safe driving and collision avoidance;
avoidance;
o Cooperative adaptive cruise control in an urban roadway; o Cooperative adaptive cruise control in a roadway;
o Platooning in a highway; o Platooning in a highway;
o Cooperative environment sensing. o Cooperative environment sensing.
These four techniques will be important elements for self-driving These four techniques will be important elements for self-driving
vehicles. vehicles.
The existing IPv6 protocol does not support wireless single-hop V2V
communications as well as wireless multi-hop V2V communications.
Thus, the IPv6 needs to be extended for both single-hop V2V
communications and multi-hop V2V communications.
Context-Aware Safety Driving (CASD) navigator [CASD] can help drivers Context-Aware Safety Driving (CASD) navigator [CASD] can help drivers
to drive safely by alerting the drivers about dangerous obstacles and to drive safely by alerting them to dangerous obstacles and
situations. That is, CASD navigator displays obstacles or situations. That is, a CASD navigator displays obstacles or
neighboring vehicles relevant to possible collisions in real-time neighboring vehicles relevant to possible collisions in real-time
through V2V networking. CASD provides vehicles with a class-based through V2V networking. CASD provides vehicles with a class-based
automatic safety action plan, which considers three situations, automatic safety action plan, which considers three situations,
namely, the Line-of-Sight unsafe, Non-Line-of-Sight unsafe, and safe namely, the Line-of-Sight unsafe, Non-Line-of-Sight unsafe, and safe
situations. This action plan can be put into action among multiple situations. This action plan can be put into action among multiple
vehicles using V2V networking. vehicles using V2V networking.
Cooperative Adaptive Cruise Control (CACC) [CA-Cruise-Control] helps Cooperative Adaptive Cruise Control (CACC) [CA-Cruise-Control] helps
vehicles to adapt their speed autonomously through V2V communication individual vehicles to adapt their speed autonomously through V2V
among vehicles according to the mobility of their predecessor and communication among vehicles according to the mobility of their
successor vehicles in an urban roadway or a highway. Thus, CACC can predecessor and successor vehicles in an urban roadway or a highway.
help adjacent vehicles to efficiently adjust their speed in an Thus, CACC can help adjacent vehicles to efficiently adjust their
interactive way through V2V networking in order to avoid collision. speed in an interactive way through V2V networking in order to avoid
a collision.
Platooning [Truck-Platooning] allows a series of vehicles (e.g., Platooning [Truck-Platooning] allows a series (or group) of vehicles
trucks) to follow each other very closely. Trucks can use V2V (e.g., trucks) to follow each other very closely. Trucks can use V2V
communication in addition to forward sensors in order to maintain communication in addition to forward sensors in order to maintain
constant clearance between two consecutive vehicles at very short constant clearance between two consecutive vehicles at very short
gaps (from 3 meters to 10 meters). Platooning can maximize the gaps (from 3 meters to 10 meters). Platooning can maximize the
throughput of vehicular traffic in a highway and reduce the gas throughput of vehicular traffic in a highway and reduce the gas
consumption because the leading vehicle can help the following consumption because the leading vehicle can help the following
vehicles to experience less air resistance. vehicles to experience less air resistance.
Cooperative-environment-sensing use cases suggest that vehicles can Cooperative-environment-sensing use cases suggest that vehicles can
share environmental information from various vehicle-mounted sensors, share environmental information (e.g., air pollution, hazards/
such as radars, LiDARs, and cameras with other vehicles and obstacles, slippery areas by snow or rain, road accidents, traffic
pedestrians. [Automotive-Sensing] introduces a millimeter-wave congestion, and driving behaviors of neighboring vehicles) from
vehicular communication for massive automotive sensing. A lot of various vehicle-mounted sensors, such as radars, LiDARs, and cameras,
data can be generated by those sensors, and these data typically need with other vehicles and pedestrians. [Automotive-Sensing] introduces
to be routed to different destinations. In addition, from the millimeter-wave vehicular communication for massive automotive
perspective of driverless vehicles, it is expected that driverless sensing. A lot of data can be generated by those sensors, and these
vehicles can be mixed with driver-operated vehicles. Through the data typically need to be routed to different destinations. In
cooperative environment sensing, driver-operated vehicles can use addition, from the perspective of driverless vehicles, it is expected
environmental information sensed by driverless vehicles for better that driverless vehicles can be mixed with driver-operated vehicles.
interaction with the other vehicles and environment. Through cooperative environment sensing, driver-operated vehicles can
use environmental information sensed by driverless vehicles for
better interaction with the other vehicles and environment. Vehicles
can also share their intended maneuvering information (e.g., lane
change, speed change, ramp in-and-out, cut-in, and abrupt braking)
with neighboring vehicles. Thus, this information sharing can help
the vehicles behave as more efficient traffic flows and minimize
unnecessary acceleration and deceleration to achieve the best ride
comfort.
To support the applications of these V2V use cases, the functions of To encourage more vehicles to participate in this cooperative
IPv6 such as VND and VSP are prerequisite for the IPv6-based packet environmental sensing, a reward system will be needed. Sensing
exchange and the secure, safe communication between two vehicles. activities of each vehicle need to be logged in either a central way
through a logging server (e.g., TCC) in the vehicular cloud or a
distributed way (e.g., blockchain [Bitcoin]) through other vehicles
or infrastructure. In the case of a blockchain, each sensing message
from a vehicle can be treated as a transaction and the neighboring
vehicles can play the role of peers in a consensus method of a
blockchain such as Proof of Work (PoW) and Proof of Stake (PoS)
[Bitcoin][Vehicular-BlockChain].
The existing IPv6 protocol does not support wireless single-hop V2V
communications as well as wireless multihop V2V communications.
Thus, the IPv6 needs to support both single-hop and multihop
communications in a wireless medium so that vehicles can communicate
with each other by V2V communications to share either an emergency
situation or road hazard in a highway.
To support applications of these V2V use cases, the functions of IPv6
such as VND and VSP are prerequisites for IPv6-based packet exchange
and secure, safe communication between two vehicles.
3.2. V2I 3.2. V2I
The use cases of V2I networking discussed in this section include The use cases of V2I networking discussed in this section include
o Navigation service; o Navigation service;
o Energy-efficient speed recommendation service; o Energy-efficient speed recommendation service;
o Accident notification service. o Accident notification service;
The existing IPv6 protocol does not support wireless multi-hop V2I o Electric vehicle (EV) charging service.
communications in a highway where RSUs are sparsely deployed, so a
vehicle can reach the wireless coverage of an RSU through the multi-
hop data forwarding of intermediate vehicles. Thus, the IPv6 needs
to be extended for multi-hop V2I communications.
A navigation service, for example, the Self-Adaptive Interactive A navigation service, for example, the Self-Adaptive Interactive
Navigation Tool (SAINT) [SAINT], using V2I networking interacts with Navigation Tool(SAINT) [SAINT], using V2I networking interacts with a
TCC for the large-scale/long-range road traffic optimization and can TCC for the large-scale/long-range road traffic optimization and can
guide individual vehicles for appropriate navigation paths in real guide individual vehicles along appropriate navigation paths in real
time. The enhanced version of SAINT [SAINTplus] can give fast moving time. The enhanced version of SAINT [SAINTplus] can give fast moving
paths to emergency vehicles (e.g., ambulance and fire engine) to let paths to emergency vehicles (e.g., ambulance and fire engine) to let
them reach an accident spot while redirecting other vehicles near the them reach an accident spot while redirecting other vehicles near the
accident spot into efficient detour paths. accident spot into efficient detour paths.
A TCC can recommend an energy-efficient speed to a vehicle that Either a TCC or an ECD can recommend an energy-efficient speed to a
depends on its traffic environment. [Fuel-Efficient] studies fuel- vehicle that depends on its traffic environment and traffic signal
efficient route and speed plans for platooned trucks. scheduling [SignalGuru]. For example, when a vehicle approaches an
intersection area and a red traffic light for the vehicle becomes
turned on, it needs to reduce its speed to save fuel consumption. In
this case, either a TCC or an ECD, which has the up-to-date
trajectory of the vehicle and the traffic light schedule, can notify
the vehicle of an appropriate speed for fuel efficiency.
[Fuel-Efficient] studies fuel-efficient route and speed plans for
platooned trucks.
The emergency communication between accident vehicles (or emergency The emergency communication between accident vehicles (or emergency
vehicles) and TCC can be performed via either IP-RSU or 4G-LTE vehicles) and a TCC can be performed via either IP-RSU or 4G-LTE
networks. The First Responder Network Authority (FirstNet) networks. The First Responder Network Authority (FirstNet)
[FirstNet] is provided by the US government to establish, operate, [FirstNet] is provided by the US government to establish, operate,
and maintain an interoperable public safety broadband network for and maintain an interoperable public safety broadband network for
safety and security network services, e.g., emergency calls. The safety and security network services, e.g., emergency calls. The
construction of the nationwide FirstNet network requires each state construction of the nationwide FirstNet network requires each state
in the US to have a Radio Access Network (RAN) that will connect to in the US to have a Radio Access Network (RAN) that will connect to
the FirstNet's network core. The current RAN is mainly constructed the FirstNet's network core. The current RAN is mainly constructed
by 4G-LTE for the communication between a vehicle and an using 4G-LTE for the communication between a vehicle and an
infrastructure node (i.e., V2I) [FirstNet-Report], but it is expected infrastructure node (i.e., V2I) [FirstNet-Report], but it is expected
that DSRC-based vehicular networks [DSRC] will be available for V2I that DSRC-based vehicular networks [DSRC] will be available for V2I
and V2V in near future. and V2V in the near future.
To support the applications of these V2I use cases, the functions of An EV charging service with V2I can facilitates the efficient battery
IPv6 such as VND, VMM, and VSP are prerequisite for the IPv6-based charging of EVs. In the case where an EV charging station is
packet exchange, the transport-layer session continuity, and the connected to an IP-RSU, an EV can be guided toward the deck of the EV
secure, safe communication between a vehicle and a server in the charging station through a battery charging server connected to the
vehicular cloud. IP-RSU. In addition to this EV charging service, other value-added
services (e.g., air firmware/software update and media streaming) can
be provided to an EV while it is charging its battery at the EV
charging station.
The existing IPv6 protocol does not support wireless multihop V2I
communications in a highway where RSUs are sparsely deployed, so a
vehicle can reach the wireless coverage of an RSU through the
multihop data forwarding of intermediate vehicles. Thus, IPv6 needs
to be extended for multihop V2I communications.
To support applications of these V2I use cases, the functions of IPv6
such as VND, VMM, and VSP are prerequisites for IPv6-based packet
exchange, transport-layer session continuity, and secure, safe
communication between a vehicle and a server in the vehicular cloud.
3.3. V2X 3.3. V2X
The use case of V2X networking discussed in this section is The use case of V2X networking discussed in this section is for a
pedestrian protection service. pedestrian protection service.
The existing IPv6 protocol does not support wireless multi-hop V2X
(or V2I2X) communications in an urban road network where RSUs are
deployed at intersections, so a vehicle (or a pedestrian's
smartphone) can reach the wireless coverage of an RSU through the
multi-hop data forwarding of intermediate vehicles (or pedestrians'
smartphones). Thus, the IPv6 needs to be extended for multi-hop V2X
(or V2I2X) communications.
A pedestrian protection service, such as Safety-Aware Navigation A pedestrian protection service, such as Safety-Aware Navigation
Application (SANA) [SANA], using V2I2P networking can reduce the Application (SANA) [SANA], using V2I2P networking can reduce the
collision of a vehicle and a pedestrian carrying a smartphone collision of a vehicle and a pedestrian carrying a smartphone
equipped with a network device for wireless communication (e.g., equipped with a network device for wireless communication (e.g., Wi-
WiFi) with an IP-RSU. Vehicles and pedestrians can also communicate Fi) with an IP-RSU. Vehicles and pedestrians can also communicate
with each other via an IP-RSU. An edge computing device behind the with each other via an IP-RSU. An edge computing device behind the
IP-RSU can collect the mobility information from vehicles and IP-RSU can collect the mobility information from vehicles and
pedestrians, compute wireless communication scheduling for the sake pedestrians, compute wireless communication scheduling for the sake
of them. This scheduling can save the battery of each pedestrian's of them. This scheduling can save the battery of each pedestrian's
smartphone by allowing it to work in sleeping mode before the smartphone by allowing it to work in sleeping mode before the
communication with vehicles, considering their mobility. communication with vehicles, considering their mobility.
For Vehicle-to-Pedestrian (V2P), a vehicle can directly communicate For Vehicle-to-Pedestrian (V2P), a vehicle can directly communicate
with a pedestrian's smartphone by V2X without IP-RSU relaying. with a pedestrian's smartphone by V2X without IP-RSU relaying.
Light-weight mobile nodes such as bicycles may also communicate Light-weight mobile nodes such as bicycles may also communicate
directly with a vehicle for collision avoidance using V2V. directly with a vehicle for collision avoidance using V2V.
To support the applications of these V2X use cases, the functions of The existing IPv6 protocol does not support wireless multihop V2X (or
IPv6 such as VND, VMM, and VSP are prerequisite for the IPv6-based V2I2X) communications in an urban road network where RSUs are
packet exchange, the transport-layer session continuity, and the deployed at intersections, so a vehicle (or a pedestrian's
secure, safe communication between a vehicle and a pedestrian either smartphone) can reach the wireless coverage of an RSU through the
directly or indirectly via an IP-RSU. multihop data forwarding of intermediate vehicles (or pedestrians'
smartphones). Thus, IPv6 needs to be extended for multihop V2X (or
V2I2X) communications.
To support applications of these V2X use cases, the functions of IPv6
such as VND, VMM, and VSP are prerequisites for IPv6-based packet
exchange, transport-layer session continuity, and secure, safe
communication between a vehicle and a pedestrian either directly or
indirectly via an IP-RSU.
4. Vehicular Networks
This section describes an example vehicular network architecture
supporting V2V, V2I, and V2X communications in vehicular networks.
It describes an internal network within a vehicle or an edge network
(called EN). It explains not only the internetworking between the
internal networks of a vehicle and an EN via wireless links, but also
the internetworking between the internal networks of two vehicles via
wireless links.
4.1. Vehicular Network Architecture
Figure 1 shows an example vehicular network architecture for V2I and
V2V in a road network [OMNI-Interface]. The vehicular network
architecture contains vehicles (including IP-OBU), IP-RSUs, Mobility
Anchor, Traffic Control Center, and Vehicular Cloud as components.
Note that the components of the vehicular network architecture can be
mapped to those of an IP-based aeronautical network architecture in
[OMNI-Interface], as shown in Figure 2.
Traffic Control Center in Vehicular Cloud Traffic Control Center in Vehicular Cloud
******************************************* *******************************************
+-------------+ * * +-------------+ * *
|Corresponding| * +-----------------+ * |Corresponding| * +-----------------+ *
| Node |<->* | Mobility Anchor | * | Node |<->* | Mobility Anchor | *
+-------------+ * +-----------------+ * +-------------+ * +-----------------+ *
* ^ * * ^ *
* | * * | *
* v * * v *
skipping to change at page 10, line 48 skipping to change at page 12, line 42
| v | | v | | v | | v | | v | | v |
| +--------+ | | +--------+ | | +--------+ | | +--------+ | | +--------+ | | +--------+ |
| |Vehicle5|===> | | |Vehicle6|===>| | |Vehicle7|==>| | |Vehicle5|===> | | |Vehicle6|===>| | |Vehicle7|==>|
| +--------+ | | +--------+ | | +--------+ | | +--------+ | | +--------+ | | +--------+ |
+-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+
Subnet1 Subnet2 Subnet3 Subnet1 Subnet2 Subnet3
(Prefix1) (Prefix2) (Prefix3) (Prefix1) (Prefix2) (Prefix3)
<----> Wired Link <....> Wireless Link ===> Moving Direction <----> Wired Link <....> Wireless Link ===> Moving Direction
Figure 1: An Exemplary Vehicular Network Architecture for V2I and V2V Figure 1: An Example Vehicular Network Architecture for V2I and V2V
+-------------------+------------------------------------+
4. Vehicular Networks | Vehicular Network | Aeronautical Network |
+===================+====================================+
This section describes an exemplary vehicular network architecture | IP-RSU | Access Router (AR) |
supporting V2V, V2I, and V2X communications in vehicular networks. +-------------------+------------------------------------+
It describes an internal network within a vehicle or an edge network | Vehicle (IP-OBU) | Mobile Node (MN) |
(called EN). It explains not only the internetworking between the +-------------------+------------------------------------+
internal networks of a vehicle and an EN via wireless links, but also | Moving Network | End User Network (EUN) |
the internetworking between the internal networks of two vehicles via +-------------------+------------------------------------+
wireless links. | Mobility Anchor | Mobility Service Endpoint (MSE) |
+-------------------+------------------------------------+
| Vehicular Cloud | Internetwork (INET) Routing System |
+-------------------+------------------------------------+
4.1. Vehicular Network Architecture Figure 2: Mapping between Vehicular Network Components and
Aeronautical Network Components
Figure 1 shows an exemplary vehicular network architecture for V2I These components are not mandatory, and they can be deployed into
and V2V in a road network. The vehicular network architecture vehicular networks in various ways. Some of them (e.g., Mobility
contains vehicles, IP-RSUs, Vehicular Cloud, Traffic Control Center, Anchor, Traffic Control Center, and Vehicular Cloud) may not be
and Mobility Anchor as components. However, some components in the needed for the vehicular networks according to target use cases in
vehicular network architecture may not be needed for vehicular Section 3.
networks, such as Vehicular Cloud, Traffic Control Center, and
Mobility Anchor.
The existing, well-known architecture such as PMIPv6 [RFC5213] can be An existing network architecture (e.g., an IP-based aeronautical
extended to a vehicular network architecture (as shown in Figure 1) network architecture [OMNI-Interface], a network architecture of
such that it can support wireless multi-hop V2I, multi-hop V2V, and PMIPv6 [RFC5213], and a low-power and lossy network architecture
multi-hop V2X (or V2I2X). [RFC6550]) can be extended to a vehicular network architecture for
multihop V2V, V2I, and V2X, as shown in Figure 1. In a highway
scenario, a vehicle may not access an RSU directly because of the
distance of the DSRC coverage (up to 1 km). For example, RPL (IPv6
Routing Protocol for Low-Power and Lossy Networks) [RFC6550] can be
extended to support a multihop V2I since a vehicle can take advantage
of other vehicles as relay nodes to reach the RSU. Also, RPL can be
extended to support both multihop V2V and V2X in the similar way.
As shown in this figure, IP-RSUs as routers and vehicles with IP-OBU As shown in this figure, IP-RSUs as routers and vehicles with IP-OBU
have wireless media interfaces for VANET. Furthermore, the wireless have wireless media interfaces for VANET. Furthermore, the wireless
media interfaces are autoconfigured with a global IPv6 prefix (e.g., media interfaces are autoconfigured with a global IPv6 prefix (e.g.,
2001:DB8:1:1::/64) to support both V2V and V2I networking. Note that 2001:DB8:1:1::/64) to support both V2V and V2I networking. Note that
2001:DB8::/32 is a documentation prefix [RFC3849] for example 2001:DB8::/32 is a documentation prefix [RFC3849] for example
prefixes in this document, and also that any routable IPv6 address prefixes in this document, and also that any routable IPv6 address
needs to be routable in a VANET and a vehicular network including IP- needs to be routable in a VANET and a vehicular network including IP-
RSUs. RSUs.
For IPv6 packets transported over IEEE 802.11-OCB, [RFC8691]
specifies several details, including Maximum Transmission Unit (MTU),
frame format, link-local address, address mapping for unicast and
multicast, stateless autoconfiguration, and subnet structure. An
Ethernet Adaptation (EA) layer is in charge of transforming some
parameters between IEEE 802.11 MAC layer and IPv6 network layer,
which is located between IEEE 802.11-OCB's logical link control layer
and IPv6 network layer. This IPv6 over 802.11-OCB can be used for
both V2V and V2I in IPv6-based vehicular networks.
In Figure 1, three IP-RSUs (IP-RSU1, IP-RSU2, and IP-RSU3) are In Figure 1, three IP-RSUs (IP-RSU1, IP-RSU2, and IP-RSU3) are
deployed in the road network and are connected with each other deployed in the road network and are connected with each other
through the wired networks (e.g., Ethernet), which are part of a through the wired networks (e.g., Ethernet). A Traffic Control
Vehicular Cloud. A Traffic Control Center (TCC) is connected to the Center (TCC) is connected to the Vehicular Cloud for the management
Vehicular Cloud for the management of IP-RSUs and vehicles in the of IP-RSUs and vehicles in the road network. A Mobility Anchor (MA)
road network. A Mobility Anchor (MA) may be located in the TCC as a may be located in the TCC as a mobility management controller.
mobility management controller, which is a controller for the Vehicle2, Vehicle3, and Vehicle4 are wirelessly connected to IP-RSU1,
mobility management of vehicles. Vehicle2, Vehicle3, and Vehicle4 IP-RSU2, and IP-RSU3, respectively. The three wireless networks of
are wirelessly connected to IP-RSU1, IP-RSU2, and IP-RSU3, IP-RSU1, IP-RSU2, and IP-RSU3 can belong to three different subnets
respectively. The three wireless networks of IP-RSU1, IP-RSU2, and (i.e., Subnet1, Subnet2, and Subnet3), respectively. Those three
IP-RSU3 can belong to three different subnets (i.e., Subnet1, subnets use three different prefixes (i.e., Prefix1, Prefix2, and
Subnet2, and Subnet3), respectively. Those three subnets use three Prefix3).
different prefixes (i.e., Prefix1, Prefix2, and Prefix3).
Multiple vehicles under the coverage of an RSU share a prefix such Multiple vehicles under the coverage of an RSU share a prefix such
that mobile nodes share a prefix of a WiFi access point in a wireless that mobile nodes share a prefix of a Wi-Fi access point in a
LAN. This is a natural characteristic in infrastructure-based wireless LAN. This is a natural characteristic in infrastructure-
wireless networks. For example, in Figure 1, two vehicles (i.e., based wireless networks. For example, in Figure 1, two vehicles
Vehicle2, and Vehicle5) can use Prefix 1 to configure their IPv6 (i.e., Vehicle2, and Vehicle5) can use Prefix 1 to configure their
global addresses for V2I communication. IPv6 global addresses for V2I communication.
A single subnet prefix announced by an RSU can span multiple vehicles A single subnet prefix announced by an RSU can span multiple vehicles
in VANET. For example, in Figure 1, for Prefix 1, three vehicles in VANET. For example, in Figure 1, for Prefix 1, three vehicles
(i.e., Vehicle1, Vehicle2, and Vehicle5) can construct a connected (i.e., Vehicle1, Vehicle2, and Vehicle5) can construct a connected
VANET. Also, for Prefix 2, two vehicles (i.e., Vehicle3 and VANET. Also, for Prefix 2, two vehicles (i.e., Vehicle3 and
Vehicle6) can construct another connected VANET, and for Prefix 3, Vehicle6) can construct another connected VANET, and for Prefix 3,
two vehicles (i.e., Vehicle4 and Vehicle7) can construct another two vehicles (i.e., Vehicle4 and Vehicle7) can construct another
connected VANET. connected VANET.
In wireless subnets in vehicular networks (e.g., Subnet1 and Subnet2 In wireless subnets in vehicular networks (e.g., Subnet1 and Subnet2
in Figure 1), vehicles can construct a connected VANET (with an in Figure 1), vehicles can construct a connected VANET (with an
arbitrary graph topology) and can communicate with each other via V2V arbitrary graph topology) and can communicate with each other via V2V
communication. Vehicle1 can communicate with Vehicle2 via V2V communication. Vehicle1 can communicate with Vehicle2 via V2V
communication, and Vehicle2 can communicate with Vehicle3 via V2V communication, and Vehicle2 can communicate with Vehicle3 via V2V
communication because they are within the wireless communication communication because they are within the wireless communication
range for each other. On the other hand, Vehicle3 can communicate range of each other. On the other hand, Vehicle3 can communicate
with Vehicle4 via the vehicular infrastructure (i.e., IP-RSU2 and IP- with Vehicle4 via the vehicular infrastructure (i.e., IP-RSU2 and IP-
RSU3) by employing V2I (i.e., V2I2V) communication because they are RSU3) by employing V2I (i.e., V2I2V) communication because they are
not within the wireless communication range for each other. not within the wireless communication range of each other.
An IPv6 mobility solution is needed in vehicular networks so that a For IPv6 packets transported over IEEE 802.11-OCB, [RFC8691]
vehicle's TCP session can be continued while it moves from an IP- specifies several details, including Maximum Transmission Unit (MTU),
RSU's wireless coverage to another IP-RSU's wireless coverage. In frame format, link-local address, address mapping for unicast and
Figure 1, assuming that Vehicle2 has a TCP session with a multicast, stateless autoconfiguration, and subnet structure. An
corresponding node in the vehicular cloud, Vehicle2 can move from IP- Ethernet Adaptation (EA) layer is in charge of transforming some
RSU1's wireless coverage to IP-RSU2's wireless coverage. In this parameters between the IEEE 802.11 MAC layer and the IPv6 network
case, a handover for Vehicle2 needs to be performed by either a host- layer, which is located between the IEEE 802.11-OCB's logical link
based mobility management scheme (e.g., MIPv6 [RFC6275]) or a control layer and the IPv6 network layer. This IPv6 over 802.11-OCB
can be used for both V2V and V2I in IPv6-based vehicular networks.
An IPv6 mobility solution is needed for the guarantee of
communication continuity in vehicular networks so that a vehicle's
TCP session can be continued, or UDP packets can be delivered to a
vehicle as a destination without loss while it moves from an IP-RSU's
wireless coverage to another IP-RSU's wireless coverage. In
Figure 1, assuming that Vehicle2 has a TCP session (or a UDP session)
with a corresponding node in the vehicular cloud, Vehicle2 can move
from IP-RSU1's wireless coverage to IP-RSU2's wireless coverage. In
this case, a handover for Vehicle2 needs to be performed by either a
host-based mobility management scheme (e.g., MIPv6 [RFC6275]) or a
network-based mobility management scheme (e.g., PMIPv6 [RFC5213]). network-based mobility management scheme (e.g., PMIPv6 [RFC5213]).
In the host-based mobility scheme, an IP-RSU plays a role of a home
agent in a visited network. On the other hand, in the network-based In the host-based mobility scheme (e.g., MIPv6), an IP-RSU plays a
mobility scheme, an MA plays a role of a mobility management role of a home agent. On the other hand, in the network-based
controller such as a Local Mobility Anchor (LMA) in PMIPv6, and an mobility scheme (e.g., PMIPv6, an MA plays a role of a mobility
IP-RSU plays a role of an access router such as a Mobile Access management controller such as a Local Mobility Anchor (LMA) in
Gateway (MAG) in PMIPv6 [RFC5213]. PMIPv6, which also serves vehicles as a home agent, and an IP-RSU
plays a role of an access router such as a Mobile Access Gateway
(MAG) in PMIPv6 [RFC5213]. The host-based mobility scheme needs
client functionality in IPv6 stack of a vehicle as a mobile node for
mobility signaling message exchange between the vehicle and home
agent. On the other hand, the network-based mobility scheme does not
need such a client functionality for a vehicle because the network
infrastructure node (e.g., MAG in PMIPv6) as a proxy mobility agent
handles the mobility signaling message exchange with the home agent
(e.g., LMA in PMIPv6) for the sake of the vehicle.
There are a scalability issue and a route optimization issue in the
network-based mobility scheme (e.g., PMIPv6) when an MA covers a
large vehicular network governing many IP-RSUs. In this case, a
distributed mobility scheme (e.g., DMM [RFC7429]) can mitigate the
scalability issue by distributing multiple MAs in the vehicular
network such that they are positioned closer to vehicles for route
optimization and bottleneck mitigation in a central MA in the
network-based mobility scheme. All these mobility approaches (i.e.,
a host-based mobility scheme, network-based mobility scheme, and
distributed mobility scheme) and a hybrid approach of a combination
of them need to provide an efficient mobility service to vehicles
moving fast and moving along with the relatively predictable
trajectories along the roadways.
In vehicular networks, the control plane can be separated from the In vehicular networks, the control plane can be separated from the
data plane for efficient mobility management and data forwarding by data plane for efficient mobility management and data forwarding by
using the concept of Software-Defined Networking (SDN) [RFC7149]. In using the concept of Software-Defined Networking (SDN)
[RFC7149][DMM-FPC]. Note that Forwarding Policy Configuration (FPC)
in [DMM-FPC], which is a flexible mobility management system, can
manage the separation of data-plane and control-plane in DMM. In
SDN, the control plane and data plane are separated for the efficient SDN, the control plane and data plane are separated for the efficient
management of forwarding elements (e.g., switches and routers) where management of forwarding elements (e.g., switches and routers) where
an SDN controller configures the forwarding elements in a centralized an SDN controller configures the forwarding elements in a centralized
way and they perform packet forwarding according to their forwarding way and they perform packet forwarding according to their forwarding
tables that are configured by the SDN controller. An MA can tables that are configured by the SDN controller. An MA as an SDN
configure and monitor its IP-RSUs and vehicles for mobility controller needs to efficiently configure and monitor its IP-RSUs and
management, location management, and security services as an SDN vehicles for mobility management, location management, and security
controller. services.
The mobility information of a GPS receiver mounted in its vehicle The mobility information of a GPS receiver mounted in its vehicle
(e.g., position, speed, and direction) can be used to accommodate (e.g., position, speed, and direction) can be used to accommodate
mobility-aware proactive handover schemes, which can perform the mobility-aware proactive handover schemes, which can perform the
handover of a vehicle according to its mobility and the wireless handover of a vehicle according to its mobility and the wireless
signal strength of a vehicle and an IP-RSU in a proactive way. signal strength of a vehicle and an IP-RSU in a proactive way.
Vehicles can use the TCC as their Home Network having a home agent Vehicles can use the TCC as their Home Network having a home agent
for mobility management as in MIPv6 [RFC6275] and PMIPv6 [RFC5213], for mobility management as in MIPv6 [RFC6275] and PMIPv6 [RFC5213],
so the TCC maintains the mobility information of vehicles for so the TCC (or an MA inside the TCC) maintains the mobility
location management. IP tunneling over the wireless link should be information of vehicles for location management. IP tunneling over
avoided for performance efficiency. Also, in vehicular networks, the wireless link should be avoided for performance efficiency.
asymmetric links sometimes exist and must be considered for wireless Also, in vehicular networks, asymmetric links sometimes exist and
communications such as V2V and V2I. must be considered for wireless communications such as V2V and V2I.
4.2. V2I-based Internetworking
This section discusses the internetworking between a vehicle's
internal network (i.e., moving network) and an EN's internal network
(i.e., fixed network) via V2I communication. The internal network of
a vehicle is nowadays constructed with Ethernet by many automotive
vendors [In-Car-Network]. Note that an EN can accommodate multiple
routers (or switches) and servers (e.g., ECDs, navigation server, and
DNS server) in its internal network.
A vehicle's internal network often uses Ethernet to interconnect
Electronic Control Units (ECUs) in the vehicle. The internal network
can support Wi-Fi and Bluetooth to accommodate a driver's and
passenger's mobile devices (e.g., smartphone or tablet). The network
topology and subnetting depend on each vendor's network configuration
for a vehicle and an EN. It is reasonable to consider the
interaction between the internal network and an external network
within another vehicle or an EN.
As shown in Figure 3, as internal networks, a vehicle's moving
network and an EN's fixed network are self-contained networks having
multiple subnets and having an edge router (e.g., IP-OBU and IP-RSU)
for the communication with another vehicle or another EN. The
internetworking between two internal networks via V2I communication
requires the exchange of the network parameters and the network
prefixes of the internal networks. For the efficiency, the network
prefixes of the internal networks (as a moving network) in a vehicle
need to be delegated and configured automatically. Note that a
moving network's network prefix can be called a Mobile Network Prefix
(MNP) [OMNI-Interface].
+-----------------+ +-----------------+
(*)<........>(*) +----->| Vehicular Cloud | (*)<........>(*) +----->| Vehicular Cloud |
2001:DB8:1:1::/64 | | | +-----------------+ 2001:DB8:1:1::/64 | | | +-----------------+
+------------------------------+ +---------------------------------+ +------------------------------+ +---------------------------------+
| v | | v v | | v | | v v |
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| | Host1 | |IP-OBU1| | | |IP-RSU1| | Host3 | | | | Host1 | |IP-OBU1| | | |IP-RSU1| | Host3 | |
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
skipping to change at page 14, line 33 skipping to change at page 17, line 35
| ^ ^ | | ^ ^ ^ | | ^ ^ | | ^ ^ ^ |
| | | | | | | | | | | | | | | | | |
| v v | | v v v | | v v | | v v v |
| ---------------------------- | | ------------------------------- | | ---------------------------- | | ------------------------------- |
| 2001:DB8:10:2::/64 | | 2001:DB8:20:2::/64 | | 2001:DB8:10:2::/64 | | 2001:DB8:20:2::/64 |
+------------------------------+ +---------------------------------+ +------------------------------+ +---------------------------------+
Vehicle1 (Moving Network1) EN1 (Fixed Network1) Vehicle1 (Moving Network1) EN1 (Fixed Network1)
<----> Wired Link <....> Wireless Link (*) Antenna <----> Wired Link <....> Wireless Link (*) Antenna
Figure 2: Internetworking between Vehicle and Edge Network Figure 3: Internetworking between Vehicle and Edge Network
4.2. V2I-based Internetworking
This section discusses the internetworking between a vehicle's
internal network (i.e., moving network) and an EN's internal network
(i.e., fixed network) via V2I communication. The internal network of
a vehicle is nowadays constructed with Ethernet by many automotive
vendors [In-Car-Network]. Note that an EN can accommodate multiple
routers (or switches) and servers (e.g., ECDs, navigation server, and
DNS server) in its internal network.
A vehicle's internal network often uses Ethernet to interconnect
Electronic Control Units (ECUs) in the vehicle. The internal network
can support WiFi and Bluetooth to accommodate a driver's and
passenger's mobile devices (e.g., smartphone or tablet). The network
topology and subnetting depend on each vendor's network configuration
for a vehicle and an EN. It is reasonable to consider the
interaction between the internal network and an external network
within another vehicle or an EN.
As shown in Figure 2, as internal networks, a vehicle's moving
network and an EN's fixed network are self-contained networks having
multiple subnets and having an edge router (e.g., IP-OBU and IP-RSU)
for the communication with another vehicle or another EN.
Internetworking between two internal networks via V2I communication
requires the exchange of the network parameters and the network
prefixes of the internal networks.
Figure 2 also shows internetworking between the vehicle's moving Figure 3 also shows the internetworking between the vehicle's moving
network and the EN's fixed network. There exists an internal network network and the EN's fixed network. There exists an internal network
(Moving Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and (Moving Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and
Host2), and two routers (IP-OBU1 and Router1). There exists another Host2), and two routers (IP-OBU1 and Router1). There exists another
internal network (Fixed Network1) inside EN1. EN1 has one host internal network (Fixed Network1) inside EN1. EN1 has one host
(Host3), two routers (IP-RSU1 and Router2), and the collection of (Host3), two routers (IP-RSU1 and Router2), and the collection of
servers (Server1 to ServerN) for various services in the road servers (Server1 to ServerN) for various services in the road
networks, such as the emergency notification and navigation. networks, such as the emergency notification and navigation.
Vehicle1's IP-OBU1 (as a mobile router) and EN1's IP-RSU1 (as a fixed Vehicle1's IP-OBU1 (as a mobile router) and EN1's IP-RSU1 (as a fixed
router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for
V2I networking. Thus, a host (Host1) in Vehicle1 can communicate V2I networking. Thus, a host (Host1) in Vehicle1 can communicate
with a server (Server1) in EN1 for a vehicular service through with a server (Server1) in EN1 for a vehicular service through
Vehicle1's moving network, a wireless link between IP-OBU1 and IP- Vehicle1's moving network, a wireless link between IP-OBU1 and IP-
RSU1, and EN1's fixed network. RSU1, and EN1's fixed network.
For the IPv6 communication between an IP-OBU and an IP-RSU or between For the IPv6 communication between an IP-OBU and an IP-RSU or between
two neighboring IP-OBUs, they need to know the network parameters, two neighboring IP-OBUs, they need to know the network parameters,
which include MAC layer and IPv6 layer information. The MAC layer which include MAC layer and IPv6 layer information. The MAC layer
information includes wireless link layer parameters, transmission information includes wireless link layer parameters, transmission
power level, the MAC address of an external network interface for the power level, and the MAC address of an external network interface for
internetworking with another IP-OBU or IP-RSU. The IPv6 layer the internetworking with another IP-OBU or IP-RSU. The IPv6 layer
information includes the IPv6 address and network prefix of an information includes the IPv6 address and network prefix of an
external network interface for the internetworking with another IP- external network interface for the internetworking with another IP-
OBU or IP-RSU. OBU or IP-RSU.
Through the mutual knowledge of the network parameters of internal Through the mutual knowledge of the network parameters of internal
networks, packets can be transmitted between the vehicle's moving networks, packets can be transmitted between the vehicle's moving
network and the EN's fixed network. Thus, V2I requires an efficient network and the EN's fixed network. Thus, V2I requires an efficient
protocol for the mutual knowledge of network parameters. protocol for the mutual knowledge of network parameters.
As shown in Figure 3, global IPv6 addresses are used for the wireless
link interfaces for IP-OBU and IP-RSU, but IPv6 Unique Local
Addresses (ULAs) [RFC4193] can also be used for those wireless link
interfaces as long as IPv6 packets can be routed to them in the
vehicular networks [OMNI-Interface]. For the guarantee of the
uniqueness of an IPv6 address, the configuration and control overhead
of the DAD of the wireless link interfaces should be minimized to
support the V2I and V2X communications of vehicles moving fast along
roadways.
4.3. V2V-based Internetworking
This section discusses the internetworking between the moving
networks of two neighboring vehicles via V2V communication.
Figure 4 shows the internetworking between the moving networks of two
neighboring vehicles. There exists an internal network (Moving
Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and Host2),
and two routers (IP-OBU1 and Router1). There exists another internal
network (Moving Network2) inside Vehicle2. Vehicle2 has two hosts
(Host3 and Host4), and two routers (IP-OBU2 and Router2). Vehicle1's
IP-OBU1 (as a mobile router) and Vehicle2's IP-OBU2 (as a mobile
router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for
V2V networking. Thus, a host (Host1) in Vehicle1 can communicate
with another host (Host3) in Vehicle2 for a vehicular service through
Vehicle1's moving network, a wireless link between IP-OBU1 and IP-
OBU2, and Vehicle2's moving network.
(*)<..........>(*) (*)<..........>(*)
2001:DB8:1:1::/64 | | 2001:DB8:1:1::/64 | |
+------------------------------+ +------------------------------+ +------------------------------+ +------------------------------+
| v | | v | | v | | v |
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| | Host1 | |IP-OBU1| | | |IP-OBU2| | Host3 | | | | Host1 | |IP-OBU1| | | |IP-OBU2| | Host3 | |
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
| | | | | | | | | | | | | | | |
| v v | | v v | | v v | | v v |
skipping to change at page 16, line 32 skipping to change at page 19, line 32
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
| | | | | | | | | | | | | | | |
| v v | | v v | | v v | | v v |
| ---------------------------- | | ---------------------------- | | ---------------------------- | | ---------------------------- |
| 2001:DB8:10:2::/64 | | 2001:DB8:30:2::/64 | | 2001:DB8:10:2::/64 | | 2001:DB8:30:2::/64 |
+------------------------------+ +------------------------------+ +------------------------------+ +------------------------------+
Vehicle1 (Moving Network1) Vehicle2 (Moving Network2) Vehicle1 (Moving Network1) Vehicle2 (Moving Network2)
<----> Wired Link <....> Wireless Link (*) Antenna <----> Wired Link <....> Wireless Link (*) Antenna
Figure 3: Internetworking between Two Vehicles Figure 4: Internetworking between Two Vehicles
4.3. V2V-based Internetworking
This section discusses the internetworking between the moving
networks of two neighboring vehicles via V2V communication.
Figure 3 shows internetworking between the moving networks of two As a V2V use case in Section 3.1, Figure 5 shows the linear network
neighboring vehicles. There exists an internal network (Moving topology of platooning vehicles for V2V communications where Vehicle3
Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and Host2), is the leading vehicle with a driver, and Vehicle2 and Vehicle1 are
and two routers (IP-OBU1 and Router1). There exists another internal the following vehicles without drivers.
network (Moving Network2) inside Vehicle2. Vehicle2 has two hosts
(Host3 and Host4), and two routers (IP-OBU2 and Router2). Vehicle1's
IP-OBU1 (as a mobile router) and Vehicle2's IP-OBU2 (as a mobile
router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for
V2V networking. Thus, a host (Host1) in Vehicle1 can communicate
with another host (Host3) in Vehicle2 for a vehicular service through
Vehicle1's moving network, a wireless link between IP-OBU1 and IP-
OBU2, and Vehicle2's moving network.
(*)<..................>(*)<..................>(*) (*)<..................>(*)<..................>(*)
| | | | | |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
| | | | | | | | | | | |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| |IP-OBU1| | | |IP-OBU2| | | |IP-OBU3| | | |IP-OBU1| | | |IP-OBU2| | | |IP-OBU3| |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| | | | | | | ^ | | ^ | | ^ |
| | |=====> | | |=====> | | |=====>
| v | | v | | v |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| | Host1 | | | | Host2 | | | | Host3 | | | | Host1 | | | | Host2 | | | | Host3 | |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| | | | | | | | | | | |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
Vehicle1 Vehicle2 Vehicle3 Vehicle1 Vehicle2 Vehicle3
<....> Wireless Link (*) Antenna <----> Wired Link <....> Wireless Link ===> Moving Direction
(*) Antenna
Figure 4: Multihop Internetworking between Two Vehicle Networks Figure 5: Multihop Internetworking between Two Vehicle Networks
Figure 4 shows multihop internetworking between the moving networks As shown in Figure 5, multihop internetworking is feasible among the
of two vehicles in the same VANET. For example, Host1 in Vehicle1 moving networks of three vehicles in the same VANET. For example,
can communicate with Host3 in Vehicle3 via IP-OBU1 in Vehicle1, IP- Host1 in Vehicle1 can communicate with Host3 in Vehicle3 via IP-OBU1
OBU2 in Vehicle2, and IP-OBU3 in Vehicle3 in a linear topology as in Vehicle1, IP-OBU2 in Vehicle2, and IP-OBU3 in Vehicle3 in the
shown in the figure. linear network, as shown in the figure.
5. Problem Statement 5. Problem Statement
In order to specify protocols using the abovementioned architecture In order to specify protocols using the architecture mentioned in
for VANETs, IPv6 core protocols have to be adapted to overcome Section 4.1, IPv6 core protocols have to be adapted to overcome
certain challenging aspects of vehicular networking. Since the certain challenging aspects of vehicular networking. Since the
vehicles are likely to be moving at great speed, protocol exchanges vehicles are likely to be moving at great speed, protocol exchanges
need to be completed in a time relatively small compared to the need to be completed in a time relatively short compared to the
lifetime of a link between a vehicle and an IP-RSU, or between two lifetime of a link between a vehicle and an IP-RSU, or between two
vehicles. This has a major impact on IPv6 Neighbor Discovery (ND). vehicles.
Mobility Management (MM) is also vulnerable to disconnections that
occur before the completion of identity verification and tunnel Note that if two vehicles are moving in the opposite directions in a
management. This is especially true given the unreliable nature of roadway, the relative speed of this case is two times the relative
wireless communications. Thus, this section presents key topics such speed of a vehicle passing through an RSU. The time constraint of a
as neighbor discovery and mobility management. wireless link between two nodes needs to be considered because it may
affect the lifetime of a session involving the link.
The lifetime of a session varies depending on the session's type such
as a web surfing, voice call over IP, and DNS query. Regardless of a
session's type, to guide all the IPv6 packets to their destination
host, IP mobility should be supported for the session.
Thus, the time constraint of a wireless link has a major impact on
IPv6 Neighbor Discovery (ND). Mobility Management (MM) is also
vulnerable to disconnections that occur before the completion of
identity verification and tunnel management. This is especially true
given the unreliable nature of wireless communication. This section
presents key topics such as neighbor discovery and mobility
management.
5.1. Neighbor Discovery 5.1. Neighbor Discovery
IPv6 ND [RFC4861][RFC4862] is a core part of the IPv6 protocol suite. IPv6 ND [RFC4861][RFC4862] is a core part of the IPv6 protocol suite.
IPv6 ND is designed for point-to-point links and transit links (e.g., IPv6 ND is designed for point-to-point links and transit links (e.g.,
Ethernet). It assumes an efficient and reliable support of multicast Ethernet). It assumes the efficient and reliable support of
from the link layer for various network operations such as MAC multicast and unicast from the link layer for various network
Address Resolution (AR) and Duplicate Address Detection (DAD). operations such as MAC Address Resolution (AR), Duplicate Address
Detection (DAD), and Neighbor Unreachability Detection (NUD).
Vehicles move quickly within the communication coverage of any Vehicles move quickly within the communication coverage of any
particular vehicle or IP-RSU. Before the vehicles can exchange particular vehicle or IP-RSU. Before the vehicles can exchange
application messages with each other, they need to be configured with application messages with each other, they need to be configured with
a link-local IPv6 address or a global IPv6 address, and run IPv6 ND. a link-local IPv6 address or a global IPv6 address, and run IPv6 ND.
The requirements for IPv6 ND for vehicular networks are efficient DAD
and NUD operations. An efficient DAD is required to reduce the
overhead of the DAD packets during a vehicle's travel in a road
network, which guaranteeing the uniqueness of a vehicle's global IPv6
address. An efficient NUD is required to reduce the overhead of the
NUD packets during a vehicle's travel in a road network, which
guaranteeing the accurate neighborhood information of a vehicle in
terms of adjacent vehicles and RSUs.
The legacy DAD assumes that a node with an IPv6 address can reach any The legacy DAD assumes that a node with an IPv6 address can reach any
other node with the scope of its address at the time it claims its other node with the scope of its address at the time it claims its
address, and can hear any future claim for that address by another address, and can hear any future claim for that address by another
party within the scope of its address for the duration of the address party within the scope of its address for the duration of the address
ownership. However, the partitioning and merging of VANETs makes ownership. However, the partitioning and merging of VANETs makes
this assumption frequently invalid in vehicular networks. The this assumption frequently invalid in vehicular networks. The
merging and partitioning of VANETs occurs frequently in vehicular merging and partitioning of VANETs frequently occurs in vehicular
networks. This merging and partitioning should be considered for the networks. This merging and partitioning should be considered for the
IPv6 ND such as IPv6 Stateless Address Autoconfiguration (SLAAC) IPv6 ND such as IPv6 Stateless Address Autoconfiguration (SLAAC)
[RFC4862]. Due to the merging of VANETs, two IPv6 addresses may [RFC4862]. Due to the merging of VANETs, two IPv6 addresses may
conflict with each other though they were unique before the merging. conflict with each other though they were unique before the merging.
Also, the partitioning of a VANET may make vehicles with the same Also, the partitioning of a VANET may make vehicles with the same
prefix be physically unreachable. Also, SLAAC needs to prevent IPv6 prefix be physically unreachable. Also, SLAAC needs to prevent IPv6
address duplication due to the merging of VANETs. According to the address duplication due to the merging of VANETs. According to the
merging and partitioning, a destination vehicle (as an IPv6 host) merging and partitioning, a destination vehicle (as an IPv6 host)
needs to be distinguished as either an on-link host or an off-link needs to be distinguished as either an on-link host or an off-link
host even though the source vehicle uses the same prefix with the host even though the source vehicle uses the same prefix as the
destination vehicle. destination vehicle.
To efficiently prevent the IPv6 address duplication due to the VANET To efficiently prevent IPv6 address duplication due to the VANET
partitioning and merging from happing in vehicular networks, the partitioning and merging from happening in vehicular networks, the
vehicular networks need to support a vehicular-network-wide DAD by vehicular networks need to support a vehicular-network-wide DAD by
defining a scope that is compatible with the legacy DAD. In this defining a scope that is compatible with the legacy DAD. In this
case, two vehicles can communicate with each other when there exists case, two vehicles can communicate with each other when there exists
a communication path over VANET or a combination of VANETs and IP- a communication path over VANET or a combination of VANETs and IP-
RSUs, as shown in Figure 1. By using the vehicular-network-wide DAD, RSUs, as shown in Figure 1. By using the vehicular-network-wide DAD,
vehicles can assure that their IPv6 addresses are unique in the vehicles can assure that their IPv6 addresses are unique in the
vehicular network whenever they are connected to the vehicular vehicular network whenever they are connected to the vehicular
infrastructure or become disconnected from it in the form of VANET. infrastructure or become disconnected from it in the form of VANET.
ND time-related parameters such as router lifetime and Neighbor ND time-related parameters such as router lifetime and Neighbor
Advertisement (NA) interval need to be adjusted for vehicle speed and Advertisement (NA) interval need to be adjusted for vehicle speed and
vehicle density. For example, the NA interval needs to be vehicle density. For example, the NA interval needs to be
dynamically adjusted according to a vehicle's speed so that the dynamically adjusted according to a vehicle's speed so that the
vehicle can maintain its neighboring vehicles in a stable way, vehicle can maintain its neighboring vehicles in a stable way,
considering the collision probability with the NA messages sent by considering the collision probability with the NA messages sent by
other vehicles. other vehicles.
For IPv6-based safety applications (e.g., context-aware navigation, For IPv6-based safety applications (e.g., context-aware navigation,
adaptive cruise control, and platooning) in vehicular networks, the adaptive cruise control, and platooning) in vehicular networks, the
delay-bounded data delivery is critical. Implementations for such delay-bounded data delivery is critical. IPv6 ND needs to work to
applications are not available yet. IPv6 ND needs to efficiently support those IPv6-based safety applications efficiently.
work to support IPv6-based safety applications.
Thus, in IPv6-based vehicular networking, IPv6 ND should have minimum
changes for the interoperability with the legacy IPv6 ND used in the
Internet, including the DAD and NUD operations.
5.1.1. Link Model 5.1.1. Link Model
A prefix model for a vehicular network needs to facilitate the A prefix model for a vehicular network needs to facilitate the
communication between two vehicles with the same prefix regardless of communication between two vehicles with the same prefix regardless of
the vehicular network topology as long as there exist bidirectional the vehicular network topology as long as there exist bidirectional
E2E paths between them in the vehicular network including VANETs and E2E paths between them in the vehicular network including VANETs and
IP-RSUs. This prefix model allows vehicles with the same prefix to IP-RSUs. This prefix model allows vehicles with the same prefix to
communicate with each other via a combination of multihop V2V and communicate with each other via a combination of multihop V2V and
multihop V2I with VANETs and IP-RSUs. multihop V2I with VANETs and IP-RSUs. Note that the OMNI link model
supports these multihop V2V and V2I through an OMNI multilink service
[OMNI-Interface].
IPv6 protocols work under certain assumptions for the link model that IPv6 protocols work under certain assumptions for the link model that
do not necessarily hold in a vehicular wireless link do not necessarily hold in a vehicular wireless link
[VIP-WAVE][RFC5889]. For instance, some IPv6 protocols assume [VIP-WAVE][RFC5889]. For instance, some IPv6 protocols assume
symmetry in the connectivity among neighboring interfaces [RFC6250]. symmetry in the connectivity among neighboring interfaces [RFC6250].
However, radio interference and different levels of transmission However, radio interference and different levels of transmission
power may cause asymmetric links to appear in vehicular wireless power may cause asymmetric links to appear in vehicular wireless
links. As a result, a new vehicular link model needs to consider the links. As a result, a new vehicular link model needs to consider the
asymmetry of dynamically changing vehicular wireless links. asymmetry of dynamically changing vehicular wireless links.
There is a relationship between a link and a prefix, besides the There is a relationship between a link and a prefix, besides the
different scopes that are expected from the link-local and global different scopes that are expected from the link-local and global
types of IPv6 addresses. In an IPv6 link, it is assumed that all types of IPv6 addresses. In an IPv6 link, it is assumed that all
interfaces which are configured with the same subnet prefix and with interfaces which are configured with the same subnet prefix and with
on-link bit set can communicate with each other on an IPv6 link. on-link bit set can communicate with each other on an IPv6 link.
However, the vehicular link model needs to define the relationship However, the vehicular link model needs to define the relationship
between a link and a prefix, considering the dynamics of wireless between a link and a prefix, considering the dynamics of wireless
links and the characteristics of VANET. links and the characteristics of VANET.
A VANET can have multiple links between pairs of vehicles within A VANET can have a single link between each vehicle pair within
wireless communication range, as shown in Figure 4. When two wireless communication range, as shown in Figure 5. When two
vehicles belong to the same VANET, but they are out of wireless vehicles belong to the same VANET, but they are out of wireless
communication range, they cannot communicate directly with each communication range, they cannot communicate directly with each
other. Suppose that a global-scope IPv6 prefix is assigned to VANETs other. Suppose that a global-scope IPv6 prefix (or an IPv6 ULA
in vehicular networks. Even though two vehicles in the same VANET prefix) is assigned to VANETs in vehicular networks. Even though two
configure their IPv6 addresses with the same IPv6 prefix, they may vehicles in the same VANET configure their IPv6 addresses with the
not communicate with each other not in a one hop in the same VANET same IPv6 prefix, they may not communicate with each other not in one
because of the multihop network connectivity between them. Thus, in hop in the same VANET because of the multihop network connectivity
this case, the concept of an on-link IPv6 prefix does not hold between them. Thus, in this case, the concept of an on-link IPv6
because two vehicles with the same on-link IPv6 prefix cannot prefix does not hold because two vehicles with the same on-link IPv6
communicate directly with each other. Also, when two vehicles are prefix cannot communicate directly with each other. Also, when two
located in two different VANETs with the same IPv6 prefix, they vehicles are located in two different VANETs with the same IPv6
cannot communicate with each other. When these two VANETs converge prefix, they cannot communicate with each other. When these two
to one VANET, the two vehicles can communicate with each other in a VANETs converge to one VANET, the two vehicles can communicate with
multihop fashion, for example, wheh they are Vehicle1 and Vehicle3, each other in a multihop fashion, for example, when they are Vehicle1
as shown in Figure 4. and Vehicle3, as shown in Figure 5.
From the previous observation, a vehicular link model should consider From the previous observation, a vehicular link model should consider
the frequent partitioning and merging of VANETs due to vehicle the frequent partitioning and merging of VANETs due to vehicle
mobility. Therefore, the vehicular link model needs to use an on- mobility. Therefore, the vehicular link model needs to use an on-
link prefix and off-link prefix according to the network topology of link prefix and off-link prefix according to the network topology of
vehicles such as a one-hop reachable network and a multihop reachable vehicles such as a one-hop reachable network and a multihop reachable
network (or partitioned networks). If the vehicles with the same network (or partitioned networks). If the vehicles with the same
prefix are reachable with each other in one hop, the prefix should be prefix are reachable from each other in one hop, the prefix should be
on-link. On the other hand, if some of the vehicles with the same on-link. On the other hand, if some of the vehicles with the same
prefix are not reachable with each other in one hop due to either the prefix are not reachable from each other in one hop due to either the
multihop topology in the VANET or multiple partitions, the prefix multihop topology in the VANET or multiple partitions, the prefix
should be off-link. should be off-link.
The vehicular link model needs to support the multihop routing in a The vehicular link model needs to support multihop routing in a
connected VANET where the vehicles with the same global-scope IPv6 connected VANET where the vehicles with the same global-scope IPv6
prefix are connected in one hop or multiple hops. It also needs to prefix (or the same IPv6 ULA prefix) are connected in one hop or
support the multihop routing in multiple connected VANETs through multiple hops. It also needs to support the multihop routing in
infrastructure nodes (e.g., IP-RSU) where they are connected to the multiple connected VANETs through infrastructure nodes (e.g., IP-RSU)
infrastructure. For example, in Figure 1, suppose that Vehicle1, where they are connected to the infrastructure. For example, in
Vehicle2, and Vehicle3 are configured with their IPv6 addresses based Figure 1, suppose that Vehicle1, Vehicle2, and Vehicle3 are
on the same global-scope IPv6 prefix. Vehicle1 and Vehicle3 can also configured with their IPv6 addresses based on the same global-scope
communicate with each other via either multihop V2V or multihop IPv6 prefix. Vehicle1 and Vehicle3 can also communicate with each
V2I2V. When the two vehicles of Vehicle1 and Vehicle3 are connected other via either multihop V2V or multihop V2I2V. When Vehicle1 and
in a VANET, it will be more efficient for them to directly Vehicle3 are connected in a VANET, it will be more efficient for them
communicate with each other via VANET rather than indirectly via IP- to communicate with each other directly via VANET rather than
RSUs. On the other hand, when the two vehicles of Vehicle1 and indirectly via IP-RSUs. On the other hand, when Vehicle1 and
Vehicle3 are far away from the communication range in separate VANETs Vehicle3 are far away from direct communication range in separate
and under two different IP-RSUs, they can communicate with each other VANETs and under two different IP-RSUs, they can communicate with
through the relay of IP-RSUs via V2I2V. Thus, two separate VANETs each other through the relay of IP-RSUs via V2I2V. Thus, two
can merge into one network via IP-RSU(s). Also, newly arriving separate VANETs can merge into one network via IP-RSU(s). Also,
vehicles can merge two separate VANETs into one VANET if they can newly arriving vehicles can merge two separate VANETs into one VANET
play a role of a relay node for those VANETs. if they can play the role of a relay node for those VANETs.
Thus, in IPv6-based vehicular networking, the vehicular link model
should have minimum changes for the interoperability with the legacy
IPv6 link model in an efficient fashion to support the IPv6 DAD and
NUD operations.
5.1.2. MAC Address Pseudonym 5.1.2. MAC Address Pseudonym
For the protection of drivers' privacy, a pseudonym of a MAC address For the protection of drivers' privacy, a pseudonym of a MAC address
of a vehicle's network interface should be used, so that the MAC of a vehicle's network interface should be used, so that the MAC
address can be changed periodically. However, although such a address can be changed periodically. However, although such a
pseudonym of a MAC address can protect some extent of privacy of a pseudonym of a MAC address can protect to some extent the privacy of
vehicle, it may not be able to resist attacks on vehicle a vehicle, it may not be able to resist attacks on vehicle
identification by other fingerprint information, for example, the identification by other fingerprint information, for example, the
scrambler seed embedded in IEEE 802.11-OCB frames [Scrambler-Attack]. scrambler seed embedded in IEEE 802.11-OCB frames [Scrambler-Attack].
The pseudonym of a MAC address affects an IPv6 address based on the The pseudonym of a MAC address affects an IPv6 address based on the
MAC address, and a transport-layer (e.g., TCP and and SCTP) session MAC address, and a transport-layer (e.g., TCP and SCTP) session with
with an IPv6 address pair. However, the pseudonym handling is not an IPv6 address pair. However, the pseudonym handling is not
implemented and tested yet for applications on IP-based vehicular implemented and tested yet for applications on IP-based vehicular
networking. networking.
In the ETSI standards, for the sake of security and privacy, an ITS In the ETSI standards, for the sake of security and privacy, an ITS
station (e.g., vehicle) can use pseudonyms for its network interface station (e.g., vehicle) can use pseudonyms for its network interface
identities (e.g., MAC address) and the corresponding IPv6 addresses identities (e.g., MAC address) and the corresponding IPv6 addresses
[Identity-Management]. Whenever the network interface identifier [Identity-Management]. Whenever the network interface identifier
changes, the IPv6 address based on the network interface identifier changes, the IPv6 address based on the network interface identifier
needs to be updated, and the uniqueness of the address needs to be needs to be updated, and the uniqueness of the address needs to be
checked through the DAD procedure. For vehicular networks with high checked through the DAD procedure. For vehicular networks with high
mobility and density, this DAD needs to be performed efficiently with mobility and density, this DAD needs to be performed efficiently with
minimum overhead so that the vehicles can exchange application minimum overhead so that the vehicles can exchange application
messages (e.g., collision avoidance and accident notification) with messages (e.g., collision avoidance and accident notification) with
each other with a short interval (e.g., 0.5 second) each other with a short interval (e.g., 0.5 second)
[NHTSA-ACAS-Report]. [NHTSA-ACAS-Report].
skipping to change at page 21, line 18 skipping to change at page 25, line 8
checked through the DAD procedure. For vehicular networks with high checked through the DAD procedure. For vehicular networks with high
mobility and density, this DAD needs to be performed efficiently with mobility and density, this DAD needs to be performed efficiently with
minimum overhead so that the vehicles can exchange application minimum overhead so that the vehicles can exchange application
messages (e.g., collision avoidance and accident notification) with messages (e.g., collision avoidance and accident notification) with
each other with a short interval (e.g., 0.5 second) each other with a short interval (e.g., 0.5 second)
[NHTSA-ACAS-Report]. [NHTSA-ACAS-Report].
5.1.3. Routing 5.1.3. Routing
For multihop V2V communications in either a VANET or VANETs via IP- For multihop V2V communications in either a VANET or VANETs via IP-
RSUs, a vehicular ad hoc routing protocol (e.g., AODV and OLSRv2) may RSUs, a vehicular ad hoc routing protocol (e.g., AODV or OLSRv2) may
be required to support both unicast and multicast in the links of the be required to support both unicast and multicast in the links of the
subnet with the same IPv6 prefix. However, it will be costly to run subnet with the same IPv6 prefix. However, it will be costly to run
both vehicular ND and a vehicular ad hoc routing protocol in terms of both vehicular ND and a vehicular ad hoc routing protocol in terms of
control traffic overhead [ID-Multicast-Problems]. control traffic overhead [ID-Multicast-Problems].
A routing protocol for VANET may cause redundant wireless frames in A routing protocol for a VANET may cause redundant wireless frames in
the air to check the neighborhood of each vehicle and compute the the air to check the neighborhood of each vehicle and compute the
routing information in VANET with a dynamic network topology because routing information in a VANET with a dynamic network topology
the IPv6 ND is used to check the neighborhood of each vehicle. Thus, because the IPv6 ND is used to check the neighborhood of each
the vehicular routing needs to take advantage of the IPv6 ND to vehicle. Thus, the vehicular routing needs to take advantage of the
minimize its control overhead. IPv6 ND to minimize its control overhead.
5.2. Mobility Management 5.2. Mobility Management
The seamless connectivity and timely data exchange between two end The seamless connectivity and timely data exchange between two end
points requires an efficient mobility management including location points requires efficient mobility management including location
management and handover. Most of vehicles are equipped with a GPS management and handover. Most vehicles are equipped with a GPS
receiver as part of a dedicated navigation system or a corresponding receiver as part of a dedicated navigation system or a corresponding
smartphone App. Note that The GPS receiver may not provide vehicles smartphone App. Note that the GPS receiver may not provide vehicles
with accurate location information in adverse environments such as a with accurate location information in adverse environments such as a
building area and tunnel. The location precision can be improved by building area or a tunnel. The location precision can be improved
the assistance from the IP-RSUs or a cellular system with a GPS with assistance of the IP-RSUs or a cellular system with a GPS
receiver for location information. receiver for location information.
With a GPS navigator, an efficient mobility management can be With a GPS navigator, efficient mobility management can be performed
performed with the help of vehicles periodically reporting their with the help of vehicles periodically reporting their current
current position and trajectory (i.e., navigation path) to the position and trajectory (i.e., navigation path) to the vehicular
vehicular infrastructure (having IP-RSUs and an MA in TCC). This infrastructure (having IP-RSUs and an MA in TCC). This vehicular
vehicular infrastructure can predict the future positions of the infrastructure can predict the future positions of the vehicles from
vehicles with their mobility information (i.e., the current position, their mobility information (i.e., the current position, speed,
speed, direction, and trajectory) for the efficient mobility direction, and trajectory) for efficient mobility management (e.g.,
management (e.g., proactive handover). For a better proactive proactive handover). For a better proactive handover, link-layer
handover, link-layer parameters, such as the signal strength of a parameters, such as the signal strength of a link-layer frame (e.g.,
link-layer frame (e.g., Received Channel Power Indicator (RCPI) Received Channel Power Indicator (RCPI) [VIP-WAVE]), can be used to
determine the moment of a handover between IP-RSUs along with
[VIP-WAVE]), can be used to determine the moment of a handover mobility information.
between IP-RSUs along with mobility information.
By predicting a vehicle's mobility, the vehicular infrastructure By predicting a vehicle's mobility, the vehicular infrastructure
needs to better support IP-RSUs to perform efficient SLAAC, data needs to better support IP-RSUs to perform efficient SLAAC, data
forwarding, horizontal handover (i.e., handover in wireless links forwarding, horizontal handover (i.e., handover in wireless links
using a homogeneous radio technology), and vertical handover (i.e., using a homogeneous radio technology), and vertical handover (i.e.,
handover in wireless links using heterogeneous radio technologies) in handover in wireless links using heterogeneous radio technologies) in
advance along with the movement of the vehicle. advance along with the movement of the vehicle.
For example, as shown in Figure 1, when a vehicle (e.g., Vehicle2) is For example, as shown in Figure 1, when a vehicle (e.g., Vehicle2) is
moving from the coverage of an IP-RSU (e.g., IP-RSU1) into the moving from the coverage of an IP-RSU (e.g., IP-RSU1) into the
coverage of another IP-RSU (e.g., IP-RSU2) belonging to a different coverage of another IP-RSU (e.g., IP-RSU2) belonging to a different
subnet, the IP-RSUs can proactively support the IPv6 mobility of the subnet, the IP-RSUs can proactively support the IPv6 mobility of the
vehicle, while performing the SLAAC, data forwarding, and handover vehicle, while performing the SLAAC, data forwarding, and handover
for the sake of the vehicle. for the sake of the vehicle.
For a mobility management scheme in a shared link, where the wireless
subnets of multiple IP-RSUs share the same prefix, an efficient
vehicular-network-wide DAD is required. If DHCPv6 is used to assign
a unique IPv6 address to each vehicle in this shared link, the DAD is
not required. On the other hand, for a mobility management scheme
with a unique prefix per mobile node (e.g., PMIPv6 [RFC5213] and OMNI
[OMNI-Interface]), DAD is not required because the IPv6 address of a
vehicle's external wireless interface is guaranteed to be unique.
There is a tradeoff between the prefix usage efficiency and DAD
overhead. Thus, the IPv6 address autoconfiguration for vehicular
networks needs to consider this tradeoff to support efficient
mobility management.
Therefore, for the proactive and seamless IPv6 mobility of vehicles, Therefore, for the proactive and seamless IPv6 mobility of vehicles,
the vehicular infrastructure (including IP-RSUs and MA) needs to the vehicular infrastructure (including IP-RSUs and MA) needs to
efficiently perform the mobility management of the vehicles with efficiently perform the mobility management of the vehicles with
their mobility information and link-layer information. their mobility information and link-layer information. Also, in
IPv6-based vehicular networking, IPv6 mobility management should have
minimum changes for the interoperability with the legacy IPv6
mobility management schemes such as PMIPv6, DMM, LISP, and AERO.
6. Security Considerations 6. Security Considerations
This section discusses security and privacy for IPv6-based vehicular This section discusses security and privacy for IPv6-based vehicular
networking. The security and privacy is one of key components in networking. Security and privacy are key components of IPv6-based
IPv6-based vehicular networking along with neighbor discovery and vehicular networking along with neighbor discovery and mobility
mobility management. management.
Security and privacy are paramount in the V2I, V2V, and V2X Security and privacy are paramount in V2I, V2V, and V2X networking.
networking. Only authorized vehicles need to be allowed to use the Vehicles and infrastructure must be authenticated in order to
vehicular networking. Also, in-vehicle devices (e.g., ECU) and participate in vehicular networking. Also, in-vehicle devices (e.g.,
mobile devices (e.g., smartphone) in a vehicle need to communicate ECU) and a driver/passenger's mobile devices (e.g., smartphone and
with other in-vehicle devices and mobile devices in another vehicle, tablet PC) in a vehicle need to communicate with other in-vehicle
and other servers in an IP-RSU in a secure way. Even a perfectly devices and another driver/passenger's mobile devices in another
authorized and legitimate vehicle may be hacked to run malicious vehicle, or other servers behind an IP-RSU in a secure way. Even
applications to track and collect its and other vehicles' though a vehicle is perfectly authenticated and legitimate, it may be
information. For this case, an attack mitigation process may be hacked for running malicious applications to track and collect its
required to reduce the aftermath of the malicious behaviors. and other vehicles' information. In this case, an attack mitigation
process may be required to reduce the aftermath of malicious
behaviors.
Strong security measures shall protect vehicles roaming in road Strong security measures shall protect vehicles roaming in road
networks from the attacks of malicious nodes, which are controlled by networks from the attacks of malicious nodes, which are controlled by
hackers. For safety applications, the cooperation among vehicles is hackers. For safe driving applications (e.g., context-aware
navigation, cooperative adaptive cruise control, and platooning), as
explained in Section 3.1, the cooperative action among vehicles is
assumed. Malicious nodes may disseminate wrong driving information assumed. Malicious nodes may disseminate wrong driving information
(e.g., location, speed, and direction) to make driving be unsafe. (e.g., location, speed, and direction) for disturbing safe driving.
For example, Sybil attack, which tries to confuse a vehicle with For example, a Sybil attack, which tries to confuse a vehicle with
multiple false identities, disturbs a vehicle in taking a safe multiple false identities, may disturb a vehicle from taking a safe
maneuver. This sybil attack needs to be prevented through the maneuver.
cooperation between good vehicles and IP-RSUs. Note that good
vehicles are ones with valid certificates that are determined by the
authentication process with an authentication server in the vehicular
cloud. However, applications on IPv6-based vehicular networking,
which are resilient to such a sybil attack, are not developed and
tested yet.
To identify the genuineness of vehicles against malicious vehicles, Even though vehicles can be authenticated with valid certificates by
an authentication method is required. A Vehicle Identification an authentication server in the vehicular cloud, the authenticated
Number (VIN) and a user certificate along with in-vehicle device's vehicles may harm other vehicles, so their communication activities
identifier generation can be used to efficiently authenticate a need to be logged in either a central way through a logging server
vehicle or a user through a road infrastructure node (e.g., IP-RSU) (e.g., TCC) in the vehicular cloud or a distributed way (e.g.,
connected to an authentication server in the vehicular cloud. Also, blockchain [Bitcoin]) along with other vehicles or infrastructure.
Transport Layer Security (TLS) certificates can be used for the For the non-repudiation of the harmful activities of malicious nodes,
vehicle authentication to allow secure E2E vehicle communications. a blockchain technology can be used [Bitcoin]. Each message from a
To identify the genuineness of vehicles against malicious vehicles, vehicle can be treated as a transaction and the neighboring vehicles
an authentication method is required. For vehicle authentication, can play the role of peers in a consensus method of a blockchain such
information available from a vehicle or a driver (e.g., Vehicle as PoW and PoS [Bitcoin][Vehicular-BlockChain].
Identification Number (VIN) and Transport Layer Security (TLS)
certificate [RFC8446]) needs to be used to efficiently authenticate a
vehicle or a user with the help of a road infrastructure node (e.g.,
IP-RSU) connected to an authentication server in the vehicular cloud.
For secure V2I communication, a secure channel between a mobile To identify malicious vehicles among vehicles, an authentication
router (i.e., IP-OBU) in a vehicle and a fixed router (i.e., IP-RSU) method is required. A Vehicle Identification Number (VIN) and a user
in an EN needs to be established, as shown in Figure 2. Also, for certificate (e.g., X.509 certificate [RFC5280]) along with an in-
secure V2V communication, a secure channel between a mobile router vehicle device's identifier generation can be used to efficiently
authenticate a vehicle or its driver (having a user certificate)
through a road infrastructure node (e.g., IP-RSU) connected to an
authentication server in the vehicular cloud. This authentication
can be used to identify the vehicle that will communicate with an
infrastructure node or another vehicle. In the case where a vehicle
has an internal network (called Moving Network) and elements in the
network (e.g., in-vehicle devices and a user's mobile devices), as
shown in Figure 3, the elements in the network need to be
authenticated individually for safe authentication. Also, Transport
Layer Security (TLS) certificates [RFC8446][RFC5280] can be used for
an element's authentication to allow secure E2E vehicular
communications between an element in a vehicle and another element in
a server in a vehicular cloud, or between an element in a vehicle and
another element in another vehicle.
For secure V2I communication, a secure channel (e.g., IPsec) between
a mobile router (i.e., IP-OBU) in a vehicle and a fixed router (i.e.,
IP-RSU) in an EN needs to be established, as shown in Figure 3
[RFC4301][RFC4302][RFC4303][RFC4308][RFC7296]. Also, for secure V2V
communication, a secure channel (e.g., IPsec) between a mobile router
(i.e., IP-OBU) in a vehicle and a mobile router (i.e., IP-OBU) in (i.e., IP-OBU) in a vehicle and a mobile router (i.e., IP-OBU) in
another vehicle needs to be established, as shown in Figure 3. another vehicle needs to be established, as shown in Figure 4. For
secure communication, an element in a vehicle (e.g., an in-vehicle
device and a driver/passenger's mobile device) needs to establish a
secure connection (e.g., TLS) with another element in another vehicle
or another element in a vehicular cloud (e.g., a server). Even
though IEEE 1609.2 [WAVE-1609.2] specifies security services for
applications and management messages. This WAVE specification is
optional, so if WAVE does not support the security of a WAVE frame,
either the network layer or the transport layer needs to support
security services for the WAVE frames.
For the setup of a secure channel over IPsec or TLS, the multihop V2I
communications over DSRC is required in a highway for the
authentication by involving multiple intermediate vehicles as relay
nodes toward an IP-RSU connected to an authentication server in the
vehicular cloud. The V2I communications over 5G V2X (or LTE V2X) is
required to allow a vehicle to communicate directly with a gNodeB (or
eNodeB) connected to an authentication server in the vehicular cloud.
To prevent an adversary from tracking a vehicle with its MAC address To prevent an adversary from tracking a vehicle with its MAC address
or IPv6 address, MAC address pseudonym needs to be provided to the or IPv6 address, especially for a long-living transport-layer session
vehicle; that is, each vehicle periodically updates its MAC address (e.g., voice call over IP and video streaming service), a MAC address
and the corresponding IPv6 address [RFC4086][RFC4941]. Such an pseudonym needs to be provided to each vehicle; that is, each vehicle
update of the MAC and IPv6 addresses should not interrupt the E2E periodically updates its MAC address and its IPv6 address needs to be
communications between two vehicles (or between a vehicle and an IP- updated accordingly by the MAC address change [RFC4086][RFC4941].
RSU) for a long-living transport-layer session. However, if this Such an update of the MAC and IPv6 addresses should not interrupt the
pseudonym is performed without strong E2E confidentiality, there will E2E communications between two vehicles (or between a vehicle and an
be no privacy benefit from changing MAC and IPv6 addresses, because IP-RSU) for a long-living transport-layer session. However, if this
an adversary can observe the change of the MAC and IPv6 addresses and pseudonym is performed without strong E2E confidentiality (using
track the vehicle with those addresses. either IPsec or TLS), there will be no privacy benefit from changing
MAC and IPv6 addresses, because an adversary can observe the change
of the MAC and IPv6 addresses and track the vehicle with those
addresses. Thus, the MAC address pseudonym and the IPv6 address
update should be performed with strong E2E confidentiality.
For the IPv6 ND, the DAD is required for the uniqueness of the IPv6 For the IPv6 ND, the DAD is required to ensure the uniqueness of the
address of a vehicle's wireless interface. This DAD can be used as a IPv6 address of a vehicle's wireless interface. This DAD can be used
flooding attack that makes the DAD-related ND packets are as a flooding attack that uses the DAD-related ND packets
disseminated over the VANET or vehicular networks. Thus, the disseminated over the VANET or vehicular networks. Thus, the
vehicles and IP-RSUs need to filter out suspicious ND traffic in vehicles and IP-RSUs need to filter out suspicious ND traffic in
advance. advance.
For the mobility management, a malicious vehicle can construct For mobility management, a malicious vehicle can construct multiple
multiple virtual bogus vehicles, and register them with IP-RSUs and virtual bogus vehicles, and register them with IP-RSUs and MA. This
MA. This registration makes the IP-RSUs and MA waste their registration makes the IP-RSUs and MA waste their resources. The IP-
resources. The IP-RSUs and MA need to determine whether a vehicle is RSUs and MA need to determine whether a vehicle is genuine or bogus
genuine or bogus in the mobility management. Also, the in mobility management. Also, the confidentiality of control packets
confidentiality of control packets and data packets among IP-RSUs and and data packets among IP-RSUs and MA, the E2E paths (e.g., tunnels)
MA, the E2E paths (e.g., tunnels) need to be protected by secure need to be protected by secure communication channels. In addition,
communication channels. In addition, to prevent bogus IP-RSUs and MA to prevent bogus IP-RSUs and MA from interfering with the IPv6
from interfering IPv6 mobility of vehicles, the mutual authentication mobility of vehicles, mutual authentication among them needs to be
among them needs to be performed by certificates (e.g., TLS performed by certificates (e.g., TLS certificate).
certificate).
7. Informative References 7. Informative References
[Automotive-Sensing] [Automotive-Sensing]
Choi, J., Va, V., Gonzalez-Prelcic, N., Daniels, R., R. Choi, J., Va, V., Gonzalez-Prelcic, N., Daniels, R., R.
Bhat, C., and R. W. Heath, "Millimeter-Wave Vehicular Bhat, C., and R. W. Heath, "Millimeter-Wave Vehicular
Communication to Support Massive Automotive Sensing", Communication to Support Massive Automotive Sensing",
IEEE Communications Magazine, December 2016. IEEE Communications Magazine, December 2016.
[Bitcoin] Nakamoto, S., "Bitcoin: A Peer-to-Peer Electronic Cash
System", URL: https://bitcoin.org/bitcoin.pdf, May 2009.
[CA-Cruise-Control] [CA-Cruise-Control]
California Partners for Advanced Transportation Technology California Partners for Advanced Transportation Technology
(PATH), "Cooperative Adaptive Cruise Control", [Online] (PATH), "Cooperative Adaptive Cruise Control", [Online]
Available: Available:
http://www.path.berkeley.edu/research/automated-and- http://www.path.berkeley.edu/research/automated-and-
connected-vehicles/cooperative-adaptive-cruise-control, connected-vehicles/cooperative-adaptive-cruise-control,
2017. 2017.
[CASD] Shen, Y., Jeong, J., Oh, T., and S. Son, "CASD: A [CASD] Shen, Y., Jeong, J., Oh, T., and S. Son, "CASD: A
Framework of Context-Awareness Safety Driving in Vehicular Framework of Context-Awareness Safety Driving in Vehicular
Networks", International Workshop on Device Centric Cloud Networks", International Workshop on Device Centric Cloud
(DC2), March 2016. (DC2), March 2016.
[DMM-FPC] Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
Moses, D., and C. Perkins, "Protocol for Forwarding Policy
Configuration (FPC) in DMM", draft-ietf-dmm-fpc-cpdp-13
(work in progress), March 2020.
[DSRC] ASTM International, "Standard Specification for [DSRC] ASTM International, "Standard Specification for
Telecommunications and Information Exchange Between Telecommunications and Information Exchange Between
Roadside and Vehicle Systems - 5 GHz Band Dedicated Short Roadside and Vehicle Systems - 5 GHz Band Dedicated Short
Range Communications (DSRC) Medium Access Control (MAC) Range Communications (DSRC) Medium Access Control (MAC)
and Physical Layer (PHY) Specifications", and Physical Layer (PHY) Specifications",
ASTM E2213-03(2010), October 2010. ASTM E2213-03(2010), October 2010.
[EU-2008-671-EC] [EU-2008-671-EC]
European Union, "Commission Decision of 5 August 2008 on European Union, "Commission Decision of 5 August 2008 on
the Harmonised Use of Radio Spectrum in the 5875 - 5905 the Harmonised Use of Radio Spectrum in the 5875 - 5905
skipping to change at page 26, line 10 skipping to change at page 31, line 10
Lim, H., Volker, L., and D. Herrscher, "Challenges in a Lim, H., Volker, L., and D. Herrscher, "Challenges in a
Future IP/Ethernet-based In-Car Network for Real-Time Future IP/Ethernet-based In-Car Network for Real-Time
Applications", ACM/EDAC/IEEE Design Automation Conference Applications", ACM/EDAC/IEEE Design Automation Conference
(DAC), June 2011. (DAC), June 2011.
[ISO-ITS-IPv6] [ISO-ITS-IPv6]
ISO/TC 204, "Intelligent Transport Systems - ISO/TC 204, "Intelligent Transport Systems -
Communications Access for Land Mobiles (CALM) - IPv6 Communications Access for Land Mobiles (CALM) - IPv6
Networking", ISO 21210:2012, June 2012. Networking", ISO 21210:2012, June 2012.
[ISO-ITS-IPv6-AMD1]
ISO/TC 204, "Intelligent Transport Systems -
Communications Access for Land Mobiles (CALM) - IPv6
Networking - Amendment 1", ISO 21210:2012/AMD 1:2017,
September 2017.
[NHTSA-ACAS-Report] [NHTSA-ACAS-Report]
National Highway Traffic Safety Administration (NHTSA), National Highway Traffic Safety Administration (NHTSA),
"Final Report of Automotive Collision Avoidance Systems "Final Report of Automotive Collision Avoidance Systems
(ACAS) Program", DOT HS 809 080, August 2000. (ACAS) Program", DOT HS 809 080, August 2000.
[OMNI-Interface]
Templin, F. and A. Whyman, "Transmission of IPv6 Packets
over Overlay Multilink Network (OMNI) Interfaces", draft-
templin-6man-omni-interface-24 (work in progress), June
2020.
[RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On- [RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On-
Demand Distance Vector (AODV) Routing", RFC 3561, July Demand Distance Vector (AODV) Routing", RFC 3561, July
2003. 2003.
[RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", [RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology",
RFC 3753, June 2004. RFC 3753, June 2004.
[RFC3849] Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix [RFC3849] Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
Reserved for Documentation", RFC 3849, July 2004. Reserved for Documentation", RFC 3849, July 2004.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", RFC 4086, June "Randomness Requirements for Security", RFC 4086, June
2005. 2005.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", RFC 4193, October 2005.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.
[RFC4302] Kent, S., "IP Authentication Header", RFC 4302, December
2005.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, December 2005.
[RFC4308] Hoffman, P., "Cryptographic Suites for IPsec", RFC 4308,
December 2005.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP Version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP Version 6 (IPv6)", RFC 4861,
September 2007. September 2007.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007. Address Autoconfiguration", RFC 4862, September 2007.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, September 2007. IPv6", RFC 4941, September 2007.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V., [RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, August 2008. RFC 5213, August 2008.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC5415] Calhoun, P., Montemurro, M., and D. Stanley, "Control And [RFC5415] Calhoun, P., Montemurro, M., and D. Stanley, "Control And
Provisioning of Wireless Access Points (CAPWAP) Protocol Provisioning of Wireless Access Points (CAPWAP) Protocol
Specification", RFC 5415, March 2009. Specification", RFC 5415, March 2009.
[RFC5889] Baccelli, E. and M. Townsley, "IP Addressing Model in Ad [RFC5889] Baccelli, E. and M. Townsley, "IP Addressing Model in Ad
Hoc Networks", RFC 5889, September 2010. Hoc Networks", RFC 5889, September 2010.
[RFC6250] Thaler, D., "Evolution of the IP Model", RFC 6250, May [RFC6250] Thaler, D., "Evolution of the IP Model", RFC 6250, May
2011. 2011.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, July 2011. Support in IPv6", RFC 6275, July 2011.
[RFC6550] Winter, T., Thubert, P., Brandt, A., Hui, J., Kelsey, R.,
Levis, P., Pister, K., Struik, R., Vasseur, JP., and R.
Alexander, "RPL: IPv6 Routing Protocol for Low-Power and
Lossy Networks", RFC 6550, March 2012.
[RFC6706] Templin, F., "Asymmetric Extended Route Optimization
(AERO)", RFC 6706, August 2012.
[RFC6775] Shelby, Z., Chakrabarti, S., Nordmark, E., and C. Bormann, [RFC6775] Shelby, Z., Chakrabarti, S., Nordmark, E., and C. Bormann,
"Neighbor Discovery Optimization for IPv6 over Low-Power "Neighbor Discovery Optimization for IPv6 over Low-Power
Wireless Personal Area Networks (6LoWPANs)", RFC 6775, Wireless Personal Area Networks (6LoWPANs)", RFC 6775,
November 2012. November 2012.
[RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
Locator/ID Separation Protocol (LISP)", RFC 6830, January
2013.
[RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined [RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined
Networking: A Perspective from within a Service Provider Networking: A Perspective from within a Service Provider
Environment", RFC 7149, March 2014. Environment", RFC 7149, March 2014.
[RFC7181] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg, [RFC7181] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
"The Optimized Link State Routing Protocol Version 2", "The Optimized Link State Routing Protocol Version 2",
RFC 7181, April 2014. RFC 7181, April 2014.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", RFC 7296, October 2014.
[RFC7333] Chan, H., Liu, D., Seite, P., Yokota, H., and J. Korhonen, [RFC7333] Chan, H., Liu, D., Seite, P., Yokota, H., and J. Korhonen,
"Requirements for Distributed Mobility Management", "Requirements for Distributed Mobility Management",
RFC 7333, August 2014. RFC 7333, August 2014.
[RFC7429] Liu, D., Zuniga, JC., Seite, P., Chan, H., and CJ. [RFC7429] Liu, D., Zuniga, JC., Seite, P., Chan, H., and CJ.
Bernardos, "Distributed Mobility Management: Current Bernardos, "Distributed Mobility Management: Current
Practices and Gap Analysis", RFC 7429, January 2015. Practices and Gap Analysis", RFC 7429, January 2015.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 8200, July 2017. (IPv6) Specification", RFC 8200, July 2017.
skipping to change at page 28, line 17 skipping to change at page 34, line 17
Networks", Springer Lecture Notes in Computer Science Networks", Springer Lecture Notes in Computer Science
(LNCS), Vol. 9502, December 2015. (LNCS), Vol. 9502, December 2015.
[Scrambler-Attack] [Scrambler-Attack]
Bloessl, B., Sommer, C., Dressier, F., and D. Eckhoff, Bloessl, B., Sommer, C., Dressier, F., and D. Eckhoff,
"The Scrambler Attack: A Robust Physical Layer Attack on "The Scrambler Attack: A Robust Physical Layer Attack on
Location Privacy in Vehicular Networks", IEEE 2015 Location Privacy in Vehicular Networks", IEEE 2015
International Conference on Computing, Networking and International Conference on Computing, Networking and
Communications (ICNC), February 2015. Communications (ICNC), February 2015.
[SignalGuru]
Koukoumidis, E., Peh, L., and M. Martonosi, "SignalGuru:
Leveraging Mobile Phones for Collaborative Traffic Signal
Schedule Advisory", ACM MobiSys, June 2011.
[TR-22.886-3GPP]
3GPP, "Study on Enhancement of 3GPP Support for 5G V2X
Services", 3GPP TR 22.886/Version 16.2.0, December 2018.
[Truck-Platooning] [Truck-Platooning]
California Partners for Advanced Transportation Technology California Partners for Advanced Transportation Technology
(PATH), "Automated Truck Platooning", [Online] Available: (PATH), "Automated Truck Platooning", [Online] Available:
http://www.path.berkeley.edu/research/automated-and- http://www.path.berkeley.edu/research/automated-and-
connected-vehicles/truck-platooning, 2017. connected-vehicles/truck-platooning, 2017.
[TS-23.285-3GPP] [TS-23.285-3GPP]
3GPP, "Architecture Enhancements for V2X Services", 3GPP 3GPP, "Architecture Enhancements for V2X Services", 3GPP
TS 23.285, June 2018. TS 23.285/Version 16.2.0, December 2019.
[TS-23.287-3GPP]
3GPP, "Architecture Enhancements for 5G System (5GS) to
Support Vehicle-to-Everything (V2X) Services", 3GPP
TS 23.287/Version 16.2.0, March 2020.
[Vehicular-BlockChain]
Dorri, A., Steger, M., Kanhere, S., and R. Jurdak,
"BlockChain: A Distributed Solution to Automotive Security
and Privacy", IEEE Communications Magazine, Vol. 55, No.
12, December 2017.
[VIP-WAVE] [VIP-WAVE]
Cespedes, S., Lu, N., and X. Shen, "VIP-WAVE: On the Cespedes, S., Lu, N., and X. Shen, "VIP-WAVE: On the
Feasibility of IP Communications in 802.11p Vehicular Feasibility of IP Communications in 802.11p Vehicular
Networks", IEEE Transactions on Intelligent Transportation Networks", IEEE Transactions on Intelligent Transportation
Systems, vol. 14, no. 1, March 2013. Systems, vol. 14, no. 1, March 2013.
[WAVE-1609.0] [WAVE-1609.0]
IEEE 1609 Working Group, "IEEE Guide for Wireless Access IEEE 1609 Working Group, "IEEE Guide for Wireless Access
in Vehicular Environments (WAVE) - Architecture", IEEE Std in Vehicular Environments (WAVE) - Architecture", IEEE Std
skipping to change at page 29, line 5 skipping to change at page 36, line 5
[WAVE-1609.3] [WAVE-1609.3]
IEEE 1609 Working Group, "IEEE Standard for Wireless IEEE 1609 Working Group, "IEEE Standard for Wireless
Access in Vehicular Environments (WAVE) - Networking Access in Vehicular Environments (WAVE) - Networking
Services", IEEE Std 1609.3-2016, April 2016. Services", IEEE Std 1609.3-2016, April 2016.
[WAVE-1609.4] [WAVE-1609.4]
IEEE 1609 Working Group, "IEEE Standard for Wireless IEEE 1609 Working Group, "IEEE Standard for Wireless
Access in Vehicular Environments (WAVE) - Multi-Channel Access in Vehicular Environments (WAVE) - Multi-Channel
Operation", IEEE Std 1609.4-2016, March 2016. Operation", IEEE Std 1609.4-2016, March 2016.
Appendix A. Changes from draft-ietf-ipwave-vehicular-networking-13 Appendix A. Changes from draft-ietf-ipwave-vehicular-networking-14
The following changes are made from draft-ietf-ipwave-vehicular- The following changes are made from draft-ietf-ipwave-vehicular-
networking-13: networking-14:
o This version is revised based on the comments from Carlos
Bernardos.
o The definition of Mobility Anchor (MA) is clarified with a
reference to PMIPv6.
o In Vehicular Neighbor Discovery, Vehicular Mobility Management,
and Vehicular Security and Privacy, the prefix of "Vehicular" is
explained to represent extensions of the existing protocols rather
than new "vehicular-specific" functions.
o In Section 4.1, an exemplary vehicular network architecture is
explained as an extension of the existing network architecture of
PMIPv6 for multi-hop V2V, V2I, and V2X (or V2I2X).
o For the IPv6 communication between an IP-OBU and an IP-RSU or
between two neighboring IP-OBUs, the requirements of knowing the
network parameters are addressed rather than the network parameter
sharing as a solution.
o In Figure 1, the prefix sharing of multiple vehicles under an RSU
is explained such that it is the same as the prefix sharing in a
WiFi LAN.
o The separation of the control plane and data plane is explained by
referring to the concept of SDN and the relationship between the
SDN controller and forwarding elements.
o In Figure 2, the topology of a vehicle's internal network is
justified with the reference to a real car network
[In-Car-Network].
o The discussion on ND timers is modified, focusing on a problem o This version is revised based on the comments from eight
rather than a solution. reviewers: Nancy Cam-Winget (Cisco), Fred L. Templin (The Boeing
Company), Jung-Soo Park (ETRI), Zeungil (Ben) Kim (Hyundai
Motors), Kyoungjae Sun (Soongsil University), Zhiwei Yan (CNNIC),
Yong-Joon Joe (LSware), and Peter E. Yee (Akayla).
Appendix B. Acknowledgments Appendix B. Acknowledgments
This work was supported by Institute of Information & Communications This work was supported by Institute of Information & Communications
Technology Planning & Evaluation (IITP) grant funded by the Korea Technology Planning & Evaluation (IITP) grant funded by the Korea
MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based
Security Intelligence Technology Development for the Customized Security Intelligence Technology Development for the Customized
Security Service Provisioning). Security Service Provisioning).
This work was supported in part by the MSIT (Ministry of Science and This work was supported in part by the MSIT (Ministry of Science and
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