rfc9365.original   rfc9365.txt 
IPWAVE Working Group J. Jeong, Ed. Internet Engineering Task Force (IETF) J. Jeong, Ed.
Internet-Draft Sungkyunkwan University Request for Comments: 9365 Sungkyunkwan University
Intended status: Informational 24 October 2022 Category: Informational March 2023
Expires: 27 April 2023 ISSN: 2070-1721
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-30
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, for explains use cases using V2V, V2I, and V2X networking. Next, for
IPv6-based vehicular networks, it makes a gap analysis of current IPv6-based vehicular networks, it makes a gap analysis of current
IPv6 protocols (e.g., IPv6 Neighbor Discovery, Mobility Management, IPv6 protocols (e.g., IPv6 Neighbor Discovery, mobility management,
and Security & Privacy). as well as security and privacy).
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This document is not an Internet Standards Track specification; it is
provisions of BCP 78 and BCP 79. published for informational purposes.
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approved by the IESG are candidates for any level of Internet
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This Internet-Draft will expire on 27 April 2023. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9365.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Use Cases
3.1. V2V . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1. V2V
3.2. V2I . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2. V2I
3.3. V2X . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3. V2X
4. Vehicular Networks . . . . . . . . . . . . . . . . . . . . . 12 4. Vehicular Networks
4.1. Vehicular Network Architecture . . . . . . . . . . . . . 13 4.1. Vehicular Network Architecture
4.2. V2I-based Internetworking . . . . . . . . . . . . . . . . 15 4.2. V2I-Based Internetworking
4.3. V2V-based Internetworking . . . . . . . . . . . . . . . . 19 4.3. V2V-Based Internetworking
5. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 22 5. Problem Statement
5.1. Neighbor Discovery . . . . . . . . . . . . . . . . . . . 23 5.1. Neighbor Discovery
5.1.1. Link Model . . . . . . . . . . . . . . . . . . . . . 26 5.1.1. Link Model
5.1.2. MAC Address Pseudonym . . . . . . . . . . . . . . . . 27 5.1.2. MAC Address Pseudonym
5.1.3. Routing . . . . . . . . . . . . . . . . . . . . . . . 28 5.1.3. Routing
5.2. Mobility Management . . . . . . . . . . . . . . . . . . . 29 5.2. Mobility Management
6. Security Considerations . . . . . . . . . . . . . . . . . . . 31 6. Security Considerations
6.1. Security Threats in Neighbor Discovery . . . . . . . . . 32 6.1. Security Threats in Neighbor Discovery
6.2. Security Threats in Mobility Management . . . . . . . . . 34 6.2. Security Threats in Mobility Management
6.3. Other Threats . . . . . . . . . . . . . . . . . . . . . . 34 6.3. Other Threats
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 7. IANA Considerations
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 37 8. References
8.1. Normative References . . . . . . . . . . . . . . . . . . 37 8.1. Normative References
8.2. Informative References . . . . . . . . . . . . . . . . . 38 8.2. Informative References
Appendix A. Support of Multiple Radio Technologies for V2V . . . 50 Appendix A. Support of Multiple Radio Technologies for V2V
Appendix B. Support of Multihop V2X Networking . . . . . . . . . 50 Appendix B. Support of Multihop V2X Networking
Appendix C. Support of Mobility Management for V2I . . . . . . . 52 Appendix C. Support of Mobility Management for V2I
Appendix D. Support of MTU Diversity for IP-based Vehicular Appendix D. Support of MTU Diversity for IP-Based Vehicular
Networks . . . . . . . . . . . . . . . . . . . . . . . . 53 Networks
Appendix E. Acknowledgments . . . . . . . . . . . . . . . . . . 54 Acknowledgments
Appendix F. Contributors . . . . . . . . . . . . . . . . . . . . 54 Contributors
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 56 Author's Address
1. Introduction 1. Introduction
Vehicular networking studies have mainly focused on improving road Vehicular networking studies have mainly focused on improving road
safety and efficiency, and also enabling entertainment in vehicular safety and efficiency and also enabling entertainment in vehicular
networks. To proliferate the use cases of vehicular networks, networks. To proliferate the use cases of vehicular networks,
several governments and private organizations have committed to several governments and private organizations have committed to
allocate dedicated spectrum for vehicular communications. The allocating dedicated spectrum for vehicular communications. The
Federal Communications Commission (FCC) in the US allocated wireless Federal Communications Commission (FCC) in the US allocated wireless
channels for Dedicated Short-Range Communications (DSRC) [DSRC] in channels for Dedicated Short-Range Communications (DSRC) [DSRC] in
the Intelligent Transportation Systems (ITS) with the frequency band the Intelligent Transportation Systems (ITS) with the frequency band
of 5.850 - 5.925 GHz (i.e., 5.9 GHz band). In November 2020, the FCC of 5.850 - 5.925 GHz (i.e., 5.9 GHz band). In November 2020, the FCC
adjusted the lower 45 MHz (i.e., 5.850 - 5.895 GHz) of the 5.9 GHz adjusted the lower 45 MHz (i.e., 5.850 - 5.895 GHz) of the 5.9 GHz
band for unlicensed use instead of DSRC-dedicated use band for unlicensed use instead of DSRC-dedicated use
[FCC-ITS-Modification]. DSRC-based wireless communications can [FCC-ITS-Modification]. DSRC-based wireless communications can
support vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), support vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I),
and vehicle-to-everything (V2X) networking. The European Union (EU) and vehicle-to-everything (V2X) networking. The European Union (EU)
allocated radio spectrum for safety-related and non-safety-related allocated radio spectrum for safety-related and non-safety-related
skipping to change at page 3, line 24 skipping to change at line 116
part of the Commission Decision 2008/671/EC [EU-2008-671-EC]. Most part of the Commission Decision 2008/671/EC [EU-2008-671-EC]. Most
other countries and regions in the world have adopted the 5.9 GHz other countries and regions in the world have adopted the 5.9 GHz
band for vehicular networks, though different countries use different band for vehicular networks, though different countries use different
ways to divide the band into channels. ways to divide the band into channels.
For direct inter-vehicular wireless connectivity, IEEE has amended For direct inter-vehicular wireless connectivity, IEEE has amended
standard 802.11 (commonly known as Wi-Fi) to enable safe driving standard 802.11 (commonly known as Wi-Fi) to enable safe driving
services based on DSRC for the Wireless Access in Vehicular services based on DSRC for the Wireless Access in Vehicular
Environments (WAVE) system. The Physical Layer (L1) and Data Link Environments (WAVE) system. The Physical Layer (L1) and Data Link
Layer (L2) issues are addressed in IEEE 802.11p [IEEE-802.11p] for Layer (L2) issues are addressed in IEEE 802.11p [IEEE-802.11p] for
the PHY and MAC of the DSRC, while IEEE 1609.2 [WAVE-1609.2] covers the PHY and MAC layers of the DSRC, while IEEE Std 1609.2
security aspects, IEEE 1609.3 [WAVE-1609.3] defines related services [WAVE-1609.2] covers security aspects, IEEE Std 1609.3 [WAVE-1609.3]
at network and transport layers, and IEEE 1609.4 [WAVE-1609.4] defines related services at network and transport layers, and IEEE
specifies the multichannel operation. IEEE 802.11p was first a Std 1609.4 [WAVE-1609.4] specifies the multichannel operation. IEEE
separate amendment, but was later rolled into the base 802.11 802.11p was first a separate amendment but was later rolled into the
standard (IEEE 802.11-2012) as IEEE 802.11 Outside the Context of a base 802.11 standard (IEEE Std 802.11-2012) as IEEE 802.11 Outside
Basic Service Set (OCB) in 2012 [IEEE-802.11-OCB]. the Context of a Basic Service Set (OCB) in 2012 [IEEE-802.11-OCB].
3GPP has standardized Cellular Vehicle-to-Everything (C-V2X) 3GPP has standardized Cellular Vehicle-to-Everything (C-V2X)
communications to support V2X in LTE mobile networks (called LTE V2X) communications to support V2X in LTE mobile networks (called LTE V2X)
and V2X in 5G mobile networks (called 5G V2X) [TS-23.285-3GPP] and V2X in 5G mobile networks (called 5G V2X) [TS-23.285-3GPP]
[TR-22.886-3GPP][TS-23.287-3GPP]. With C-V2X, vehicles can directly [TR-22.886-3GPP] [TS-23.287-3GPP]. With C-V2X, vehicles can directly
communicate with each other without relay nodes (e.g., eNodeB in LTE communicate with each other without relay nodes (e.g., eNodeB in LTE
and gNodeB in 5G). and gNodeB in 5G).
Along with these WAVE standards and C-V2X standards, regardless of a Along with these WAVE standards and C-V2X standards, regardless of a
wireless access technology under the IP stack of a vehicle, vehicular wireless access technology under the IP stack of a vehicle, vehicular
networks can operate IP mobility with IPv6 [RFC8200] and Mobile IPv6 networks can operate IP mobility with IPv6 [RFC8200], that is, Mobile
protocols (e.g., Mobile IPv6 (MIPv6) [RFC6275], Proxy MIPv6 (PMIPv6) IPv6 protocols, e.g., Mobile IPv6 (MIPv6) [RFC6275], Proxy Mobile
[RFC5213], Distributed Mobility Management (DMM) [RFC7333], Network IPv6 (PMIPv6) [RFC5213], Distributed Mobility Management (DMM)
Mobility (NEMO) [RFC3963], and Locator/ID Separation Protocol (LISP) [RFC7333], Network Mobility (NEMO) [RFC3963], and the Locator/ID
[I-D.ietf-lisp-rfc6830bis]. In addition, ISO has approved a standard Separation Protocol (LISP) [RFC9300]. In addition, ISO has approved
specifying the IPv6 network protocols and services to be used for a standard specifying the IPv6 network protocols and services to be
Communications Access for Land Mobiles (CALM) used for Communications Access for Land Mobiles (CALM) [ISO-ITS-IPv6]
[ISO-ITS-IPv6][ISO-ITS-IPv6-AMD1]. [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, for use cases for using V2V, V2I, and V2X networking in ITS. Next, for
IPv6-based vehicular networks, it makes a gap analysis of current IPv6-based vehicular networks, it makes a gap analysis of current
IPv6 protocols (e.g., IPv6 Neighbor Discovery, Mobility Management, IPv6 protocols (e.g., IPv6 Neighbor Discovery, mobility management,
and Security & Privacy) so that those protocols can be tailored to as well as security and privacy) so that those protocols can be
IPv6-based vehicular networking. Thus, this document is intended to tailored to IPv6-based vehicular networking. Thus, this document is
motivate development of key protocols for IPWAVE. intended to motivate 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:
* Context-Awareness: A vehicle can be aware of spatial-temporal 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].
* DMM: "Distributed Mobility Management" [RFC7333][RFC7429]. Distributed Mobility Management (DMM): See [RFC7333] [RFC7429].
* Edge Computing Device (ECD): It is a computing device (or server) Edge Computing Device (ECD): This is a computing device (or server)
at edge for vehicles and vulnerable road users. It co-locates at the edge of the network for vehicles and vulnerable road users.
with or connects to an IP-RSU, which has a powerful computing It co-locates with or connects to an IP Roadside Unit (IP-RSU),
capability for different kinds of computing tasks, such as image which has a powerful computing capability for different kinds of
processing and classification. computing tasks, such as image processing and classification.
* Edge Network (EN): It is an access network that has an IP-RSU for Edge Network (EN): This 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 On-Board
wired communication with other network devices (e.g., routers, IP- Unit (IP-OBU) and wired communication with other network devices
RSUs, ECDs, servers, and MA). It may have a global navigation (e.g., routers, IP-RSUs, ECDs, servers, and Mobility Anchors
satellite system (GNSS), such as Global Positioning System (GPS), (MAs)). It may use a Global Navigation Satellite System (GNSS)
radio receiver for its position recognition and the localization such as Global Positioning System (GPS) with a GNSS receiver for
service for the sake of vehicles. its position recognition and the localization service for the sake
of vehicles.
* IP-OBU: "Internet Protocol On-Board Unit": An IP-OBU denotes a Evolved Node B (eNodeB): This is a base station entity that supports
computer situated in a vehicle (e.g., car, bicycle, autobike, the Long Term Evolution (LTE) air interface.
motorcycle, and a similar one), which has a basic processing
ability and can be driven by a low-power CPU (e.g., ARM). It has
at least one IP interface that runs in IEEE 802.11-OCB and has an
"OBU" transceiver. Also, it may have an IP interface that runs in
Cellular V2X (C-V2X) [TS-23.285-3GPP]
[TR-22.886-3GPP][TS-23.287-3GPP]. It can play the role of a
router connecting multiple computers (or in-vehicle devices)
inside a vehicle. See the definition of the term "IP-OBU" in
[RFC8691].
* IP-RSU: "IP Roadside Unit": An IP-RSU is situated along the road. Internet Protocol On-Board Unit (IP-OBU): An IP-OBU denotes a
It has at least two distinct IP-enabled interfaces. The wireless computer situated in a vehicle (e.g., car, bicycle, electric bike,
motorcycle, or similar), which has a basic processing ability and
can be driven by a low-power CPU (e.g., ARM). It has at least one
IP interface that runs in IEEE 802.11-OCB and has an "OBU"
transceiver. Also, it may have an IP interface that runs in
Cellular V2X (C-V2X) [TS-23.285-3GPP] [TR-22.886-3GPP]
[TS-23.287-3GPP]. It can play the role of a router connecting
multiple computers (or in-vehicle devices) inside a vehicle. See
the definition of the term "IP-OBU" in [RFC8691].
IP Roadside Unit (IP-RSU): An IP-RSU is situated along the road. 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 [IEEE-802.11-OCB]. An
with the IP-OBU over an 802.11 wireless link operating in OCB IP-RSU communicates with the IP-OBU over an 802.11 wireless link
mode. Also, it may have a third IP-enabled wireless interface operating in OCB mode. One of its IP-enabled interfaces is
running in 3GPP C-V2X in addition to the IP-RSU defined in connected to the wired network for wired communication with other
[RFC8691]. An IP-RSU is similar to an Access Network Router network devices (e.g., routers, IP-RSUs, ECDs, servers, and MAs).
(ANR), defined in [RFC3753], and a Wireless Termination Point Also, it may have another IP-enabled wireless interface running in
(WTP), defined in [RFC5415]. See the definition of the term "IP- 3GPP C-V2X in addition to the IP-RSU defined in [RFC8691]. An IP-
RSU" in [RFC8691]. RSU is similar to an Access Network Router (ANR), defined in
[RFC3753], and a Wireless Termination Point (WTP), defined in
[RFC5415]. See the definition of the term "IP-RSU" in [RFC8691].
* LiDAR: "Light Detection and Ranging". It is a scanning device to Light Detection and Ranging (LiDAR): This is a method for measuring
measure a distance to an object by emitting pulsed laser light and a distance to an object by emitting pulsed laser light and
measuring the reflected pulsed light. measuring the reflected pulsed light.
* Mobility Anchor (MA): A node that maintains IPv6 addresses and Mobility Anchor (MA): This is a node that maintains IPv6 addresses
mobility information of vehicles in a road network to support and mobility information of vehicles in a road network to support
their IPv6 address autoconfiguration and mobility management with their IPv6 address autoconfiguration and mobility management with
a binding table. An MA has End-to-End (E2E) connections (e.g., a binding table. An MA has end-to-end (E2E) connections (e.g.,
tunnels) with IP-RSUs under its control for the address tunnels) with IP-RSUs under its control for the IPv6 address
autoconfiguration and mobility management of the vehicles. This autoconfiguration and mobility management of the vehicles. This
MA is similar to a Local Mobility Anchor (LMA) in PMIPv6 [RFC5213] MA is similar to a Local Mobility Anchor (LMA) in PMIPv6 [RFC5213]
for network-based mobility management. for network-based mobility management.
* OCB: "Outside the Context of a Basic Service Set - BSS". It is a Next Generation Node B (gNodeB): This is a base station entity that
mode of operation in which a Station (STA) is not a member of a supports the 5G New Radio (NR) air interface.
BSS and does not utilize IEEE Std 802.11 authentication,
association, or data confidentiality [IEEE-802.11-OCB].
* 802.11-OCB: It refers to the mode specified in IEEE Std Outside the Context of a BSS (OCB): This is a mode of operation in
which a station (STA) is not a member of a Basic Service Set (BSS)
and does not utilize IEEE Std 802.11 authentication, association,
or data confidentiality [IEEE-802.11-OCB].
802.11-OCB: This 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'. dot11OCBActivated is 'true'.
* Platooning: Moving vehicles can be grouped together to reduce air- 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 lead 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
follow the leading vehicle [Truck-Platooning]. follow the lead vehicle [Truck-Platooning].
* Traffic Control Center (TCC): A system that manages road Traffic Control Center (TCC): This is a system that manages road
infrastructure nodes (e.g., IP-RSUs, MAs, traffic signals, and infrastructure nodes (e.g., IP-RSUs, MAs, traffic signals, and
loop detectors), and also maintains vehicular traffic statistics loop detectors) and also maintains vehicular traffic statistics
(e.g., average vehicle speed and vehicle inter-arrival time per (e.g., average vehicle speed and vehicle inter-arrival time per
road segment) and vehicle information (e.g., a vehicle's road segment) and vehicle information (e.g., a vehicle's
identifier, position, direction, speed, and trajectory as a identifier, position, direction, speed, and trajectory as a
navigation path). TCC is part of a vehicular cloud for vehicular navigation path). TCC is part of a Vehicular Cloud for vehicular
networks. networks.
* Urban Air Mobility (UAM): It refers to using lower-altitude Urban Air Mobility (UAM): This refers to using lower-altitude
aircraft to transport passengers or cargo in urban and suburban aircraft to transport passengers or cargo in urban and suburban
areas. The carriers used for UAM can be manned or unmanned areas. The carriers used for UAM can be manned or unmanned
vehicles, which can include traditional helicopters, electrical vehicles, which can include helicopters, electric vertical take-
vertical-takeoff-and-landing aircraft (eVTOL), and unmanned aerial off and landing (eVTOL) aircraft, and unmanned aerial vehicles
vehicles (UAV). (UAVs).
* Vehicle: A Vehicle in this document is a node that has an IP-OBU Vehicle: This is a node that has an IP-OBU for wireless
for wireless communication with other vehicles and IP-RSUs. It communication with other vehicles and IP-RSUs. It has a GNSS
has a GNSS radio navigation receiver for efficient navigation. radio navigation receiver for efficient navigation. Any device
Any device having an IP-OBU and a GNSS receiver (e.g., smartphone having an IP-OBU and a GNSS receiver (e.g., smartphone and tablet
and tablet PC) can be regarded as a vehicle in this document. PC) can be regarded as a vehicle in this document.
* Vehicular Ad Hoc Network (VANET): A network that consists of Vehicular Ad Hoc Network (VANET): This is 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.
* Vehicular Cloud: A cloud infrastructure for vehicular networks, Vehicular Cloud: This is a cloud infrastructure for vehicular
having compute nodes, storage nodes, and network forwarding networks, having compute nodes, storage nodes, and network
elements (e.g., switch and router). forwarding elements (e.g., switch and router).
* V2D: "Vehicle to Device". It is the wireless communication Vehicle to Device (V2D): This is the wireless communication between
between a vehicle and a device (e.g., smartphone and IoT device). a vehicle and a device (e.g., smartphone and IoT (Internet of
Things) device).
* V2P: "Vehicle to Pedestrian". It is the wireless communication Vehicle to Pedestrian (V2P): This is the wireless communication
between a vehicle and a pedestrian's device (e.g., smartphone and between a vehicle and a pedestrian's device (e.g., smartphone and
IoT device). IoT device).
* V2I2V: "Vehicle to Infrastructure to Vehicle". It is the wireless Vehicle to Infrastructure to Vehicle (V2I2V): This 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).
* V2I2X: "Vehicle to Infrastructure to Everything". It is the Vehicle to Infrastructure to Everything (V2I2X): This is the
wireless communication between a vehicle and another entity (e.g., wireless communication between a vehicle and another entity (e.g.,
vehicle, smartphone, and IoT device) via an infrastructure node vehicle, smartphone, and IoT device) via an infrastructure node
(e.g., IP-RSU). (e.g., IP-RSU).
* V2X: "Vehicle to Everything". It is the wireless communication Vehicle to Everything (V2X): This is the wireless communication
between a vehicle and any entity (e.g., vehicle, infrastructure between a vehicle and any entity (e.g., vehicle, infrastructure
node, smartphone, and IoT device), including V2V, V2I, and V2D. node, smartphone, and IoT device), including V2V, V2I, V2D, and
V2P.
* VMM: "Vehicular Mobility Management". It is an IPv6-based Vehicular Mobility Management (VMM): This is IPv6-based mobility
mobility management for vehicular networks. management for vehicular networks.
* VND: "Vehicular Neighbor Discovery". It is an IPv6 ND extension Vehicular Neighbor Discovery (VND): This is an IPv6 ND (Neighbor
for vehicular networks. Discovery) extension for vehicular networks.
* VSP: "Vehicular Security and Privacy". It is an IPv6-based Vehicular Security and Privacy (VSP): This is IPv6-based security
security and privacy term for vehicular networks. and privacy for vehicular networks.
* WAVE: "Wireless Access in Vehicular Environments" [WAVE-1609.0]. Wireless Access in Vehicular Environments (WAVE): See [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).
IP is widely used among popular end-user devices (e.g., smartphone IP is widely used among popular end-user devices (e.g., smartphone
and tablet) in the Internet. Applications (e.g., navigator and tablet) in the Internet. Applications (e.g., navigator
application) for those devices can be extended such that the V2V use application) for those devices can be extended such that the V2V use
cases in this section can work with IPv6 as a network layer protocol cases in this section can work with IPv6 as a network layer protocol
and IEEE 802.11-OCB as a link layer protocol. In addition, IPv6 and IEEE 802.11-OCB as a link-layer protocol. In addition, IPv6
security needs to be extended to support those V2V use cases in a security needs to be extended to support those V2V use cases in a
safe, secure, privacy-preserving way. safe, secure, privacy-preserving way.
The use cases presented in this section serve as the description and The use cases presented in this section serve as the description and
motivation for the need to augment IPv6 and its protocols to motivation for the need to augment IPv6 and its protocols to
facilitate "Vehicular IPv6". Section 5 summarizes the overall facilitate "Vehicular IPv6". Section 5 summarizes the overall
problem statement and IPv6 requirements. Note that the adjective problem statement and IPv6 requirements. Note that the adjective
"Vehicular" in this document is used to represent extensions of "Vehicular" in this document is used to represent extensions of
existing protocols such as IPv6 Neighbor Discovery, IPv6 Mobility existing protocols, such as IPv6 Neighbor Discovery, IPv6 Mobility
Management (e.g., PMIPv6 [RFC5213] and DMM [RFC7429]), and IPv6 Management (e.g., PMIPv6 [RFC5213] and DMM [RFC7429]), and IPv6
Security and Privacy Mechanisms rather than new "vehicular-specific" Security and Privacy Mechanisms rather than new "vehicular-specific"
functions. functions.
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:
* Context-aware navigation for safe driving and collision avoidance; * Context-aware navigation for driving safely and avoiding
collisions
* Collision avoidance service of end systems of Urban Air Mobility * Collision avoidance service of end systems of Urban Air Mobility
(UAM); (UAM)
* Cooperative adaptive cruise control in a roadway; * Cooperative adaptive cruise control on a roadway
* Platooning in a highway; * Platooning on a highway
* Cooperative environment sensing. * Cooperative environment sensing
The above use cases are examples for using V2V networking, which can The above use cases are examples for using V2V networking, which can
be extended to other terrestrial vehicles, river/sea ships, railed be extended to other terrestrial vehicles, river/sea ships, railed
vehicles, or UAM end systems. vehicles, or UAM end systems.
Context-Aware Safety Driving (CASD) navigator [CASD] can help drivers A Context-Aware Safety Driving (CASD) navigator [CASD] can help
to drive safely by alerting them to dangerous obstacles and drivers to drive safely as a context-aware navigation service [CNP]
situations. That is, a CASD navigator displays obstacles or by alerting them to dangerous obstacles and situations. That is, a
neighboring vehicles relevant to possible collisions in real-time CASD navigator displays obstacles or neighboring vehicles relevant to
through V2V networking. CASD provides vehicles with a class-based possible collisions in real time through V2V networking. CASD
automatic safety action plan, which considers three situations, provides vehicles with a class-based automatic safety action plan
namely, the Line-of-Sight unsafe, Non-Line-of-Sight unsafe, and safe that considers three situations, namely, the Line-of-Sight unsafe,
situations. This action plan can be put into action among multiple Non-Line-of-Sight unsafe, and safe situations. This action plan can
vehicles using V2V networking. be put into action among multiple vehicles using V2V networking.
A collision avoidance service of UAM end systems in air can be A service for collision avoidance of in-air UAM end systems is one
envisioned as a use case in air vehicular environments possible use case in air vehicular environments [UAM-ITS]. This use
[I-D.templin-ipwave-uam-its]. This use case is similar to the case is similar to that of a context-aware navigator for terrestrial
context-aware navigator for terrestrial vehicles. Through V2V vehicles. Through V2V coordination, those UAM end systems (e.g.,
coordination, those UAM end systems (e.g., drones) can avoid a drones) can avoid a dangerous situation (e.g., collision) in three-
dangerous situation (e.g., collision) in three-dimensional space dimensional space rather than two-dimensional space for terrestrial
rather than two-dimensional space for terrestrial vehicles. Also, vehicles. Also, a UAM end system (e.g., flying car), when only a few
UAM end systems (e.g., flying car) with only a few meters off the hundred meters off the ground, can communicate with terrestrial
ground can communicate with terrestrial vehicles with wireless vehicles with wireless communication technologies (e.g., DSRC, LTE,
communication technologies (e.g., DSRC, LTE, and C-V2X). Thus, V2V and C-V2X). Thus, V2V means any vehicle to any vehicle, whether the
means any vehicle to any vehicle, whether the vehicles are ground- vehicles are ground level or not.
level or not.
Cooperative Adaptive Cruise Control (CACC) [CA-Cruise-Control] helps Cooperative Adaptive Cruise Control (CACC) [CA-Cruise-Control] helps
individual vehicles to adapt their speed autonomously through V2V individual vehicles to adapt their speed autonomously through V2V
communication among vehicles according to the mobility of their communication among vehicles according to the mobility of their
predecessor and successor vehicles in an urban roadway or a highway. predecessor and successor vehicles on an urban roadway or a highway.
Thus, CACC can help adjacent vehicles to efficiently adjust their Thus, CACC can help adjacent vehicles to efficiently adjust their
speed in an interactive way through V2V networking in order to avoid speed in an interactive way through V2V networking in order to avoid
a collision. a collision.
Platooning [Truck-Platooning] allows a series (or group) of vehicles Platooning [Truck-Platooning] allows a series (or group) of vehicles
(e.g., trucks) to follow each other very closely. Trucks can use V2V (e.g., trucks) to follow each other very closely. Vehicles can use
communication in addition to forward sensors in order to maintain V2V 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 to 10 meters). Platooning can maximize the throughput
throughput of vehicular traffic in a highway and reduce the gas of vehicular traffic on a highway and reduce the gas consumption
consumption because the leading vehicle can help the following because the lead vehicle can help the following vehicles experience
vehicles to experience less air resistance. less air resistance.
Cooperative-environment-sensing use cases suggest that vehicles can Cooperative-environment-sensing use cases suggest that vehicles can
share environmental information (e.g., air pollution, hazards/ share environmental information (e.g., air pollution, hazards,
obstacles, slippery areas by snow or rain, road accidents, traffic obstacles, slippery areas by snow or rain, road accidents, traffic
congestion, and driving behaviors of neighboring vehicles) from congestion, and driving behaviors of neighboring vehicles) from
various vehicle-mounted sensors, such as radars, LiDARs, and cameras, various vehicle-mounted sensors, such as radars, LiDAR systems, and
with other vehicles and pedestrians. [Automotive-Sensing] introduces cameras, with other vehicles and pedestrians. [Automotive-Sensing]
millimeter-wave vehicular communication for massive automotive introduces millimeter-wave vehicular communication for massive
sensing. A lot of data can be generated by those sensors, and these automotive sensing. A lot of data can be generated by those sensors,
data typically need to be routed to different destinations. In and these data typically need to be routed to different destinations.
addition, from the perspective of driverless vehicles, it is expected In addition, from the perspective of driverless vehicles, it is
that driverless vehicles can be mixed with driver-operated vehicles. expected that driverless vehicles can be mixed with driver-operated
Through cooperative environment sensing, driver-operated vehicles can vehicles. Through cooperative environment sensing, driver-operated
use environmental information sensed by driverless vehicles for vehicles can use environmental information sensed by driverless
better interaction with the other vehicles and environment. Vehicles vehicles for better interaction with the other vehicles and
can also share their intended maneuvering information (e.g., lane environment. Vehicles can also share their intended maneuvering
change, speed change, ramp in-and-out, cut-in, and abrupt braking) information (e.g., lane change, speed change, ramp in-and-out, cut-
with neighboring vehicles. Thus, this information sharing can help in, and abrupt braking) with neighboring vehicles. Thus, this
the vehicles behave as more efficient traffic flows and minimize information sharing can help the vehicles behave as more efficient
unnecessary acceleration and deceleration to achieve the best ride traffic flows and minimize unnecessary acceleration and deceleration
comfort. to achieve the best ride comfort.
To support applications of these V2V use cases, the required To support applications of these V2V use cases, the required
functions of IPv6 include IPv6-based packet exchange in both control functions of IPv6 include (a) IPv6-based packet exchange in both
and data planes, and secure, safe communication between two vehicles. control and data planes and (b) secure, safe communication between
For the support of V2V under multiple radio technologies (e.g., DSRC two vehicles. For the support of V2V under multiple radio
and 5G V2X), refer to Appendix A. technologies (e.g., DSRC and 5G V2X), refer to Appendix A.
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:
* Navigation service; * Navigation service
* Energy-efficient speed recommendation service; * Energy-efficient speed recommendation service
* Accident notification service; * Accident notification service
* Electric vehicle (EV) charging service; * Electric Vehicle (EV) charging service
* UAM navigation service with efficient battery charging. * UAM navigation service with efficient battery charging
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]) that uses V2I networking interacts with a
a TCC for the large-scale/long-range road traffic optimization and TCC for the large-scale/long-range road traffic optimization and can
can guide individual vehicles along appropriate navigation paths in guide individual vehicles along appropriate navigation paths in real
real time. The enhanced version of SAINT [SAINTplus] can give fast time. The enhanced version of SAINT [SAINTplus] can give fast-moving
moving paths to emergency vehicles (e.g., ambulance and fire engine) paths to emergency vehicles (e.g., ambulance and fire engine) to let
to let them reach an accident spot while redirecting other vehicles them reach an accident spot while redirecting other vehicles near the
near the accident spot into efficient detour paths. accident spot into efficient detour paths.
Either a TCC or an ECD can recommend an energy-efficient speed to a Either a TCC or an ECD can recommend an energy-efficient speed to a
vehicle that depends on its traffic environment and traffic signal vehicle that depends on its traffic environment and traffic signal
scheduling [SignalGuru]. For example, when a vehicle approaches an scheduling [SignalGuru]. For example, when a vehicle approaches an
intersection area and a red traffic light for the vehicle becomes intersection area and a red traffic light for the vehicle becomes
turned on, it needs to reduce its speed to save fuel consumption. In 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 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 trajectory of the vehicle and the traffic light schedule, can notify
the vehicle of an appropriate speed for fuel efficiency. the vehicle of an appropriate speed for fuel efficiency.
[Fuel-Efficient] studies fuel-efficient route and speed plans for [Fuel-Efficient] covers fuel-efficient route and speed plans for
platooned trucks. platooned trucks.
The emergency communication between accident vehicles (or emergency The emergency communication between vehicles in an accident (or
vehicles) and a TCC can be performed via either IP-RSU, 4G-LTE or 5G emergency-response vehicles) and a TCC can be performed via either
networks. The First Responder Network Authority (FirstNet) IP-RSUs or 4G-LTE or 5G networks. The First Responder Network
[FirstNet] is provided by the US government to establish, operate, Authority [FirstNet] is provided by the US government to establish,
and maintain an interoperable public safety broadband network for operate, and maintain an interoperable public safety broadband
safety and security network services, e.g., emergency calls. The network for safety and security network services, e.g., emergency
construction of the nationwide FirstNet network requires each state calls. The construction of the nationwide FirstNet network requires
in the US to have a Radio Access Network (RAN) that will connect to each state in the US to have a Radio Access Network (RAN) that will
the FirstNet's network core. The current RAN is mainly constructed connect to the FirstNet's network core. The current RAN is mainly
using 4G-LTE for the communication between a vehicle and an constructed using 4G-LTE for 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 the near future. An equivalent project in Europe is and V2V in the near future. An equivalent project in Europe is
called Public Safety Communications Europe (PSCE) [PSCE], which is called Public Safety Communications Europe [PSCE], which is
developing a network for emergency communications. developing a network for emergency communications.
An EV charging service with V2I can facilitate the efficient battery An EV charging service with V2I can facilitate the efficient battery
charging of EVs. In the case where an EV charging station is charging of EVs. In the case where an EV charging station is
connected to an IP-RSU, an EV can be guided toward the deck of the EV connected to an IP-RSU, an EV can be guided toward the deck of the EV
charging station or be notified that the charging station is out of charging station or be notified that the charging station is out of
service through a battery charging server connected to the IP-RSU. service through a battery charging server connected to the IP-RSU.
In addition to this EV charging service, other value-added services In addition to this EV charging service, other value-added services
(e.g., firmware/software update over-the-air and media streaming) can (e.g., firmware/software update over-the-air and media streaming) can
be provided to an EV while it is charging its battery at the EV be provided to an EV while it is charging its battery at the EV
charging station. For a UAM navigation service, an efficient battery charging station. For a UAM navigation service, an efficient battery
charging plan can improve the battery charging schedule of UAM end charging plan can improve the battery charging schedule of UAM end
systems (e.g., drone) for long-distance flying [CBDN]. For this systems (e.g., drones) for long-distance flying [CBDN]. For this
battery charging schedule, a UAM end system can communicate with a battery charging schedule, a UAM end system can communicate with a
cloud server via an infrastructure node (e.g., IP-RSU). This cloud cloud server via an infrastructure node (e.g., IP-RSU). This cloud
server can coordinate the battery charging schedules of multiple UAM server can coordinate the battery charging schedules of multiple UAM
end systems for their efficient navigation path, considering flight end systems for their efficient navigation path, considering flight
time from their current position to a battery charging station, time from their current position to a battery charging station,
waiting time in a waiting queue at the station, and battery charging waiting time in a waiting queue at the station, and battery charging
time at the station. time at the station.
In some scenarios such as vehicles moving in highways or staying in In some scenarios, such as vehicles moving on highways or staying in
parking lots, a V2V2I network is necessary for vehicles to access the parking lots, a V2V2I network is necessary for vehicles to access the
Internet since some vehicles may not be covered by an IP-RSU. For Internet since some vehicles may not be covered by an IP-RSU. For
those vehicles, a few relay vehicles can help to build the Internet those vehicles, a few relay vehicles can help to build the Internet
access. For the nested NEMO described in [RFC4888], hosts inside a access. For the nested NEMO described in [RFC4888], hosts inside a
vehicle shown in Figure 3 for the case of V2V2I may have the same vehicle shown in Figure 3 for the case of V2V2I may have the same
issue in the nested NEMO scenario. issue in the nested NEMO scenario.
To better support these use cases, the existing IPv6 protocol must be To better support these use cases, the existing IPv6 protocol must be
augmented either through protocol changes or by including a new augmented either through protocol changes or by including a new
adaptation layer in the architecture that efficiently maps IPv6 to a adaptation layer in the architecture that efficiently maps IPv6 to a
diversity of link layer technologies. Augmentation is necessary to diversity of link-layer technologies. Augmentation is necessary to
support wireless multihop V2I communications in a highway where RSUs support wireless multihop V2I communications on a highway where RSUs
are sparsely deployed, so a vehicle can reach the wireless coverage are sparsely deployed so that a vehicle can reach the wireless
of an IP-RSU through the multihop data forwarding of intermediate coverage of an IP-RSU through the multihop data forwarding of
vehicles as packet forwarders. Thus, IPv6 needs to be extended for intermediate vehicles as packet forwarders. Thus, IPv6 needs to be
multihop V2I communications. extended for multihop V2I communications.
To support applications of these V2I use cases, the required To support applications of these V2I use cases, the required
functions of IPv6 include IPv6 communication enablement with functions of IPv6 include IPv6 communication enablement with
neighborhood discovery and IPv6 address management, reachability with neighborhood discovery and IPv6 address management; reachability with
adapted network models and routing methods, transport-layer session adapted network models and routing methods; transport-layer session
continuity, and secure, safe communication between a vehicle and an continuity; and secure, safe communication between a vehicle and an
infrastructure node (e.g., IP-RSU) in the vehicular network. infrastructure node (e.g., IP-RSU) in the vehicular network.
3.3. V2X 3.3. V2X
The use case of V2X networking discussed in this section is for a The use case of V2X networking discussed in this section is for a
vulnerable road user (VRU) (e.g., pedestrian and cyclist) protection protection service for a vulnerable road user (VRU), e.g., a
service. Note that the application area of this use case is pedestrian or cyclist. Note that the application area of this use
currently limited to a specific environment, such as construction case is currently limited to a specific environment, such as
sites, plants, and factories, since not every VRU (e.g., children) in construction sites, plants, and factories, since not every VRU in a
a public area (e.g., streets) is equipped with a smart device (e.g., public area is equipped with a smart device (e.g., not every child on
smartphone, smart watch, and tablet). a road has a smartphone, smart watch, or tablet).
A VRU protection service, such as Safety-Aware Navigation Application A VRU protection service, such as the Safety-Aware Navigation
(SANA) [SANA], using V2I2P networking can reduce the collision of a Application [SANA], using V2I2P networking can reduce the collision
vehicle and a pedestrian carrying a smartphone equipped with a of a vehicle and a pedestrian carrying a smartphone equipped with a
network device for wireless communication (e.g., Wi-Fi, DSRC, 4G/5G network device for wireless communication (e.g., Wi-Fi, DSRC, 4G/5G
V2X, and BLE) with an IP-RSU. Vehicles and pedestrians can also V2X, and Bluetooth Low Energy (BLE)) with an IP-RSU. Vehicles and
communicate with each other via an IP-RSU. An edge computing device pedestrians can also communicate with each other via an IP-RSU. An
behind the IP-RSU can collect the mobility information from vehicles ECD behind the IP-RSU can collect the mobility information from
and pedestrians, compute wireless communication scheduling for the vehicles and pedestrians, and then compute wireless communication
sake of them. This scheduling can save the battery of each scheduling for the sake of them. This scheduling can save the
pedestrian's smartphone by allowing it to work in sleeping mode battery of each pedestrian's smartphone by allowing it to work in
before the communication with vehicles, considering their mobility. sleeping mode before communication with vehicles, considering their
The location information of a VRU from a smart device (e.g., mobility. The location information of a VRU from a smart device
smartphone) is multicasted only to the nearby vehicles. The true (e.g., smartphone) is multicasted only to the nearby vehicles. The
identifiers of a VRU's smart device shall be protected, and only the true identifiers of a VRU's smart device shall be protected, and only
type of the VRU, such as pedestrian, cyclist, and scooter, is the type of the VRU, such as pedestrian, cyclist, or scooter, is
disclosed to the nearby vehicles. disclosed to the nearby vehicles.
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. Note that directly with a vehicle for collision avoidance using V2V. Note that
it is true that either a pedestrian or a cyclist may have a higher it is true that either a pedestrian or a cyclist may have a higher
risk of being hit by a vehicle if they are not with a smartphone in risk of being hit by a vehicle if they are not with a smartphone in
the current setting. For this case, other human sensing technologies the current setting. For this case, other human-sensing technologies
(e.g., moving object detection in images and wireless signal-based (e.g., moving-object detection in images and wireless signal-based
human movement detection [LIFS][DFC]) can be used to provide the human movement detection [LIFS] [DFC]) can be used to provide motion
motion information of them to vehicles. A vehicle by V2V2I information to vehicles. A vehicle by V2V2I networking can obtain a
networking can obtain the motion information of a VRU via an IP-RSU VRU's motion information via an IP-RSU that either employs or
that either employs or connects to a human sensing technology. connects to a human-sensing technology.
The existing IPv6 protocol must be augmented through protocol changes The existing IPv6 protocol must be augmented through protocol changes
in order to support wireless multihop V2X or V2I2X communications in in order to support wireless multihop V2X or V2I2X communications in
an urban road network where RSUs are deployed at intersections, so a an urban road network where RSUs are deployed at intersections so
vehicle (or a pedestrian's smartphone) can reach the wireless that a vehicle (or a pedestrian's smartphone) can reach the wireless
coverage of an IP-RSU through the multihop data forwarding of coverage of an IP-RSU through the multihop data forwarding of
intermediate vehicles (or pedestrians' smartphones) as packet intermediate vehicles (or pedestrians' smartphones) as packet
forwarders. Thus, IPv6 needs to be extended for multihop V2X or forwarders. Thus, IPv6 needs to be extended for multihop V2X or
V2I2X communications. V2I2X communications.
To support applications of these V2X use cases, the required To support applications of these V2X use cases, the required
functions of IPv6 include IPv6-based packet exchange, transport-layer functions of IPv6 include IPv6-based packet exchange; transport-layer
session continuity, and secure, safe communication between a vehicle session continuity; secure, safe communication between a vehicle and
and a pedestrian either directly or indirectly via an IP-RSU, and the a pedestrian either directly or indirectly via an IP-RSU; and the
protection of identifiers of either a vehicle or smart device (such protection of identifiers of either a vehicle or smart device (such
as MAC address and IPv6 address), which is discussed in detail in as the Media Access Control (MAC) address and IPv6 address), which is
Section 6.3. discussed in detail in Section 6.3.
4. Vehicular Networks 4. Vehicular Networks
This section describes the context for vehicular networks supporting This section describes the context for vehicular networks supporting
V2V, V2I, and V2X communications. It describes an internal network V2V, V2I, and V2X communications and describes an internal network
within a vehicle or an edge network (called EN). It explains not within a vehicle or an Edge Network (EN). Additionally, this section
only the internetworking between the internal networks of a vehicle explains not only the internetworking between the internal networks
and an EN via wireless links, but also the internetworking between of a vehicle and an EN via wireless links but also the
the internal networks of two vehicles via wireless links. internetworking between the internal networks of two vehicles via
wireless links.
Traffic Control Center in Vehicular Cloud Traffic Control Center in Vehicular Cloud
******************************************* *******************************************
+-------------+ * * +-------------+ * *
|Correspondent| * +-----------------+ * |Correspondent| * +-----------------+ *
| Node |<->* | Mobility Anchor | * | Node |<->* | Mobility Anchor | *
+-------------+ * +-----------------+ * +-------------+ * +-----------------+ *
* ^ * * ^ *
* | * * | *
* v * * v *
skipping to change at page 14, line 8 skipping to change at line 627
V2V in a road network. The vehicular network architecture contains V2V in a road network. The vehicular network architecture contains
vehicles (including IP-OBU), IP-RSUs, Mobility Anchor, Traffic vehicles (including IP-OBU), IP-RSUs, Mobility Anchor, Traffic
Control Center, and Vehicular Cloud as components. These components Control Center, and Vehicular Cloud as components. These components
are not mandatory, and they can be deployed into vehicular networks are not mandatory, and they can be deployed into vehicular networks
in various ways. Some of them (e.g., Mobility Anchor, Traffic in various ways. Some of them (e.g., Mobility Anchor, Traffic
Control Center, and Vehicular Cloud) may not be needed for the Control Center, and Vehicular Cloud) may not be needed for the
vehicular networks according to target use cases in Section 3. vehicular networks according to target use cases in Section 3.
Existing network architectures, such as the network architectures of Existing network architectures, such as the network architectures of
PMIPv6 [RFC5213], RPL (IPv6 Routing Protocol for Low-Power and Lossy PMIPv6 [RFC5213], RPL (IPv6 Routing Protocol for Low-Power and Lossy
Networks) [RFC6550], and AERO/OMNI Networks) [RFC6550], Automatic Extended Route Optimization [AERO],
[I-D.templin-6man-aero][I-D.templin-6man-omni], can be extended to a and Overlay Multilink Network Interface [OMNI], can be extended to a
vehicular network architecture for multihop V2V, V2I, and V2X, as vehicular network architecture for multihop V2V, V2I, and V2X, as
shown in Figure 1. Refer to Appendix B for the detailed discussion shown in Figure 1. Refer to Appendix B for the detailed discussion
on multihop V2X networking by RPL and OMNI. Also, refer to on multihop V2X networking by RPL and OMNI. Also, refer to
Appendix A for the description of how OMNI is designed to support the Appendix A for the description of how OMNI is designed to support the
use of multiple radio technologies in V2X. Note that though AERO/ use of multiple radio technologies in V2X. Note that though AERO/
OMNI is not actually deployed in the industry, this AERO/OMNI is OMNI is not actually deployed in the industry, this AERO/OMNI is
mentioned as a possible approach for vehicular networks in this mentioned as a possible approach for vehicular networks in this
document. document.
As shown in Figure 1, IP-RSUs as routers and vehicles with IP-OBU As shown in Figure 1, IP-RSUs as routers and vehicles with IP-OBU
skipping to change at page 14, line 37 skipping to change at line 656
wirelessly connected to IP-RSU1, IP-RSU2, and IP-RSU3, respectively. wirelessly connected to IP-RSU1, IP-RSU2, and IP-RSU3, respectively.
The three wireless networks of IP-RSU1, IP-RSU2, and IP-RSU3 can The three wireless networks of IP-RSU1, IP-RSU2, and IP-RSU3 can
belong to three different subnets (i.e., Subnet1, Subnet2, and belong to three different subnets (i.e., Subnet1, Subnet2, and
Subnet3), respectively. Those three subnets use three different Subnet3), respectively. Those three subnets use three different
prefixes (i.e., Prefix1, Prefix2, and Prefix3). prefixes (i.e., Prefix1, Prefix2, and Prefix3).
Multiple vehicles under the coverage of an IP-RSU share a prefix just Multiple vehicles under the coverage of an IP-RSU share a prefix just
as mobile nodes share a prefix of a Wi-Fi access point in a wireless as mobile nodes share a prefix of a Wi-Fi access point in a wireless
LAN. This is a natural characteristic in infrastructure-based LAN. This is a natural characteristic in infrastructure-based
wireless networks. For example, in Figure 1, two vehicles (i.e., wireless networks. For example, in Figure 1, two vehicles (i.e.,
Vehicle2, and Vehicle5) can use Prefix 1 to configure their IPv6 Vehicle2 and Vehicle5) can use Prefix1 to configure their IPv6 global
global addresses for V2I communication. Alternatively, mobile nodes addresses for V2I communication. Alternatively, two vehicles can
can employ a "Bring-Your-Own-Addresses (BYOA)" (or "Bring-Your-Own- employ a "Bring Your Own Addresses (BYOA)" (or "Bring Your Own Prefix
Prefix (BYOP)") technique using their own IPv6 Unique Local Addresses (BYOP)") technique using their own IPv6 Unique Local Addresses (ULAs)
(ULAs) [RFC4193] over the wireless network. [RFC4193] over the wireless network.
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 of 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 of each other. not within the wireless communication range of each other.
As a basic definition for IPv6 packets transported over IEEE As a basic definition for IPv6 packets transported over IEEE
802.11-OCB, [RFC8691] specifies several details, including Maximum 802.11-OCB, [RFC8691] specifies several details, including Maximum
Transmission Unit (MTU), frame format, link-local address, address Transmission Unit (MTU), frame format, link-local address, address
mapping for unicast and multicast, stateless autoconfiguration, and mapping for unicast and multicast, stateless autoconfiguration, and
subnet structure. subnet structure.
An IPv6 mobility solution is needed for the guarantee of An IPv6 mobility solution is needed for the guarantee of
communication continuity in vehicular networks so that a vehicle's communication continuity in vehicular networks so that a vehicle's
TCP session can be continued, or UDP packets can be delivered to a TCP session can be continued or that UDP packets can be delivered to
vehicle as a destination without loss while it moves from an IP-RSU's a vehicle as a destination without loss while it moves from an IP-
wireless coverage to another IP-RSU's wireless coverage. In 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) Figure 1, assuming that Vehicle2 has a TCP session (or a UDP session)
with a correspondent node in the vehicular cloud, Vehicle2 can move with a correspondent node in the Vehicular Cloud, Vehicle2 can move
from IP-RSU1's wireless coverage to IP-RSU2's wireless coverage. In 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 this case, a handover for Vehicle2 needs to be performed by either a
host-based mobility management scheme (e.g., MIPv6 [RFC6275]) or 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],
NEMO [RFC3963] [RFC4885] [RFC4888], and AERO NEMO [RFC3963] [RFC4885] [RFC4888], and AERO [AERO]). This document
[I-D.templin-6man-aero]). This document describes issues in mobility describes issues in mobility management for vehicular networks in
management for vehicular networks in Section 5.2. For improving TCP Section 5.2. For improving TCP session continuity or successful UDP
session continuity or successful UDP packet delivery, the multi-path packet delivery, the Multipath TCP (MPTCP) [RFC8684] or QUIC protocol
TCP (MPTCP) [RFC8684] or QUIC protocol [RFC9000] can also be used. [RFC9000] can also be used. IP-OBUs, however, may still experience
IP-OBUs, however, may still experience more session time-out and re- more session time-out and re-establishment procedures due to lossy
establishment procedures due to lossy connections among vehicles connections among vehicles caused by the high mobility dynamics of
caused by the high mobility dynamics of them. them.
4.2. V2I-based Internetworking 4.2. V2I-Based Internetworking
This section discusses the internetworking between a vehicle's This section discusses the internetworking between a vehicle's
internal network (i.e., mobile network) and an EN's internal network internal network (i.e., mobile network) and an EN's internal network
(i.e., fixed network) via V2I communication. The internal network of (i.e., fixed network) via V2I communication. The internal network of
a vehicle is nowadays constructed with Ethernet by many automotive a vehicle is nowadays constructed with Ethernet by many automotive
vendors [In-Car-Network]. Note that an EN can accommodate multiple vendors [In-Car-Network]. Note that an EN can accommodate multiple
routers (or switches) and servers (e.g., ECDs, navigation server, and routers (or switches) and servers (e.g., ECDs, navigation server, and
DNS server) in its internal network. DNS server) in its internal network.
A vehicle's internal network often uses Ethernet to interconnect A vehicle's internal network often uses Ethernet to interconnect
skipping to change at page 16, line 20 skipping to change at line 724
for a vehicle and an EN. It is reasonable to consider interactions for a vehicle and an EN. It is reasonable to consider interactions
between the internal network of a vehicle and that of another vehicle between the internal network of a vehicle and that of another vehicle
or an EN. Note that it is dangerous if the internal network of a or an EN. Note that it is dangerous if the internal network of a
vehicle is controlled by a malicious party. These dangers can vehicle is controlled by a malicious party. These dangers can
include unauthorized driving control input and unauthorized driving include unauthorized driving control input and unauthorized driving
information disclosure to an unauthorized third party. A malicious information disclosure to an unauthorized third party. A malicious
party can be a group of hackers, a criminal group, and a competitor party can be a group of hackers, a criminal group, and a competitor
for industrial espionage or sabotage. To minimize this kind of risk, for industrial espionage or sabotage. To minimize this kind of risk,
an augmented identification and verification protocol, which has an an augmented identification and verification protocol, which has an
extra means, shall be implemented based on a basic identity extra means, shall be implemented based on a basic identity
verification process. These extra means can be certificate-based, verification process. These extra means could include approaches
biometric, credit-based, and one-time passcode (OTP) approaches in based on certificates, biometrics, credit, or One-Time Passwords
addition to a used approach [RFC8002]. The parties of the (OTPs) in addition to Host Identity Protocol certificates [RFC8002].
verification protocol can be from a built-in verification protocol in The parties of the verification protocol can be from a built-in
the current vehicle, which is pre-installed by a vehicle vendor. The verification protocol in the current vehicle, which is pre-installed
parties can also be from any verification authorities that have the by a vehicle vendor. The parties can also be from any verification
database of authenticated users. The security properties provided by authorities that have the database of authenticated users. The
a verification protocol can be identity-related information, such as security properties provided by a verification protocol can be
the genuineness of an identity, the authenticity of an identity, and identity-related information, such as the genuineness of an identity,
the ownership of an identity [RFC7427]. the authenticity of an identity, and the ownership of an identity
[RFC7427].
The augmented identification and verification protocol with extra The augmented identification and verification protocol with extra
means can support security properties such as the identification and means can support security properties such as the identification and
verification of a vehicle, driver, and passenger. First, a credit- verification of a vehicle, driver, and passenger. First, a credit-
based means is to let a vehicle classify the received messages sent based method is when a vehicle classifies the messages it received
by another host to different severity levels for driving safety in from another host into various levels based on their potential
order to calculate the credit for the sender. Based on an effects on driving safety in order to calculate the credit of that
accumulated credit, a correspondent node can verify the other party sender. Based on accumulated credit, a correspondent node can verify
to see whether it is genuine or not. Second, a certificate-based the other party to see whether it is genuine or not. Second, a
means includes a user certificate (e.g., X.509 certificate [RFC5280]) certificate-based method includes a user certificate (e.g., X.509
to authenticate a vehicle or its driver. Third, a biometric means certificate [RFC5280]) to authenticate a vehicle or its driver.
includes a fingerprint, face or voice to authenticate a driver or Third, a biometric method includes a fingerprint, face, or voice to
passenger. Lastly, one-time passcode (called OTP) means lets another authenticate a driver or passenger. Lastly, an OTP-based method lets
already-authenticated device (e.g., smartphone and tablet) of a another already-authenticated device (e.g., smartphone and tablet) of
driver or passenger be used to authenticate a driver or passenger. a driver or passenger be used to authenticate a driver or passenger.
+-----------------+ +-----------------+
(*)<........>(*) +----->| 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 17, line 38 skipping to change at line 784
+------------------------------+ +---------------------------------+ +------------------------------+ +---------------------------------+
Vehicle1 (Mobile Network1) EN1 (Fixed Network1) Vehicle1 (Mobile Network1) EN1 (Fixed Network1)
<----> Wired Link <....> Wireless Link (*) Antenna <----> Wired Link <....> Wireless Link (*) Antenna
Figure 2: Internetworking between Vehicle and Edge Network Figure 2: Internetworking between Vehicle and Edge Network
As shown in Figure 2, as internal networks, a vehicle's mobile As shown in Figure 2, as internal networks, a vehicle's mobile
network and an EN's fixed network are self-contained networks having 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) multiple subnets and having an edge router (e.g., IP-OBU and IP-RSU)
for the communication with another vehicle or another EN. The for communication with another vehicle or another EN. The
internetworking between two internal networks via V2I communication internetworking between two internal networks via V2I communication
requires the exchange of the network parameters and the network 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. For the efficiency, the network
prefixes of the internal networks (as a mobile network) in a vehicle prefixes of the internal networks (as a mobile network) in a vehicle
need to be delegated and configured automatically. Note that a need to be delegated and configured automatically. Note that a
mobile network's network prefix can be called a Mobile Network Prefix mobile network's network prefix can be called a Mobile Network Prefix
(MNP) [RFC3963]. (MNP) [RFC3963].
Figure 2 also shows the internetworking between the vehicle's mobile Figure 2 also shows the internetworking between the vehicle's mobile
network and the EN's fixed network. There exists an internal network network and the EN's fixed network. There exists an internal network
(Mobile Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and (Mobile 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 mobile 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, and the MAC address of an external network interface for power level, and the MAC address of an external network interface for
the 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 mobile
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. Note that protocol for the mutual knowledge of network parameters. Note that
from a security point of view, a perimeter-based policy enforcement from a security point of view, perimeter-based policy enforcement
can be applied to protect parts of the internal network of a vehicle. [RFC9099] can be applied to protect parts of the internal network of
a vehicle.
As shown in Figure 2, the addresses used for IPv6 transmissions over As shown in Figure 2, the addresses used for IPv6 transmissions over
the wireless link interfaces for IP-OBU and IP-RSU can be link-local the wireless link interfaces for IP-OBU and IP-RSU can be IPv6 link-
IPv6 addresses, ULAs, or global IPv6 addresses. When IPv6 addresses local addresses, ULAs, or IPv6 global addresses. When IPv6 addresses
are used, wireless interface configuration and control overhead for are used, wireless interface configuration and control overhead for
DAD [RFC4862] and Multicast Listener Discovery (MLD) Duplicate Address Detection (DAD) [RFC4862] and Multicast Listener
[RFC2710][RFC3810] should be minimized to support V2I and V2X Discovery (MLD) [RFC2710] [RFC3810] should be minimized to support
communications for vehicles moving fast along roadways. V2I and V2X communications for vehicles moving fast along roadways.
Let us consider the upload/download time of a ground vehicle when it Let us consider the upload/download time of a ground vehicle when it
passes through the wireless communication coverage of an IP-RSU. For passes through the wireless communication coverage of an IP-RSU. For
a given typical setting where 1km is the maximum DSRC communication a given typical setting where 1 km is the maximum DSRC communication
range [DSRC] and 100km/h is the speed limit in highway for ground range [DSRC] and 100 km/h is the speed limit on highways for ground
vehicles, the dwelling time can be calculated to be 72 seconds by vehicles, the dwelling time can be calculated to be 72 seconds by
dividing the diameter of the 2km (i.e., two times of DSRC dividing the diameter of the 2 km (i.e., two times the DSRC
communication range where an IP-RSU is located in the center of the communication range where an IP-RSU is located in the center of the
circle of wireless communication) by the speed limit of 100km/h circle of wireless communication) by the speed limit of 100 km/h
(i.e., about 28m/s). For the 72 seconds, a vehicle passing through (i.e., about 28 m/s). For the 72 seconds, a vehicle passing through
the coverage of an IP-RSU can upload and download data packets to/ the coverage of an IP-RSU can upload and download data packets to/
from the IP-RSU. For special cases such as emergency vehicles moving from the IP-RSU. For special cases, such as emergency vehicles
above the speed limit, the dwelling time is relatively shorter than moving above the speed limit, the dwelling time is relatively shorter
that of other vehicles. For cases of airborne vehicles, considering than that of other vehicles. For cases of airborne vehicles (i.e.,
a higher flying speed and a higher altitude, the dwelling time can be aircraft), considering a higher flying speed and a higher altitude,
much shorter. the dwelling time can be much shorter.
4.3. V2V-based Internetworking 4.3. V2V-Based Internetworking
This section discusses the internetworking between the moving This section discusses the internetworking between the mobile
networks of two neighboring vehicles via V2V communication. networks of two neighboring vehicles via V2V communication.
(*)<..........>(*) (*)<..........>(*)
(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 | |
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
skipping to change at page 20, line 4 skipping to change at line 881
| +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ | | +-------+ +-------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
| | | | | | | | | | | | | | | |
| 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 (Mobile Network1) Vehicle2 (Mobile Network2) Vehicle1 (Mobile Network1) Vehicle2 (Mobile Network2)
<----> Wired Link <....> Wireless Link (*) Antenna <----> Wired Link <....> Wireless Link (*) Antenna
Figure 3: Internetworking between Two Vehicles Figure 3: Internetworking between Two Vehicles
Figure 3 shows the internetworking between the mobile networks of two Figure 3 shows the internetworking between the mobile networks of two
neighboring vehicles. There exists an internal network (Mobile neighboring vehicles. There exists an internal network (Mobile
Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and Host2), Network1) inside Vehicle1. Vehicle1 has two hosts (Host1 and Host2)
and two routers (IP-OBU1 and Router1). There exists another internal and two routers (IP-OBU1 and Router1). There exists another internal
network (Mobile Network2) inside Vehicle2. Vehicle2 has two hosts network (Mobile Network2) inside Vehicle2. Vehicle2 has two hosts
(Host3 and Host4), and two routers (IP-OBU2 and Router2). Vehicle1's (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 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 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 V2V networking. Thus, a host (Host1) in Vehicle1 can communicate
with another host (Host3) in Vehicle2 for a vehicular service through with another host (Host3) in Vehicle2 for a vehicular service through
Vehicle1's mobile network, a wireless link between IP-OBU1 and IP- Vehicle1's mobile network, a wireless link between IP-OBU1 and IP-
OBU2, and Vehicle2's mobile network. OBU2, and Vehicle2's mobile network.
As a V2V use case in Section 3.1, Figure 4 shows the linear network As a V2V use case in Section 3.1, Figure 4 shows a linear network
topology of platooning vehicles for V2V communications where Vehicle3 topology of platooning vehicles for V2V communications where Vehicle3
is the leading vehicle with a driver, and Vehicle2 and Vehicle1 are is the lead vehicle with a driver, and Vehicle2 and Vehicle1 are the
the following vehicles without drivers. From a security point of following vehicles without drivers. From a security point of view,
view, before vehicles can be platooned, they shall be mutually before vehicles can be platooned, they shall be mutually
authenticated to reduce possible security risks. authenticated to reduce possible security risks.
(*)<..................>(*)<..................>(*) (*)<..................>(*)<..................>(*)
| | | | | |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
| | | | | | | | | | | |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| |IP-OBU1| | | |IP-OBU2| | | |IP-OBU3| | | |IP-OBU1| | | |IP-OBU2| | | |IP-OBU3| |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| ^ | | ^ | | ^ | | ^ | | ^ | | ^ |
skipping to change at page 21, line 13 skipping to change at line 934
Figure 4: Multihop Internetworking between Two Vehicle Networks Figure 4: Multihop Internetworking between Two Vehicle Networks
As shown in Figure 4, multihop internetworking is feasible among the As shown in Figure 4, multihop internetworking is feasible among the
mobile networks of three vehicles in the same VANET. For example, mobile networks of three vehicles in the same VANET. For example,
Host1 in Vehicle1 can communicate with Host3 in Vehicle3 via IP-OBU1 Host1 in Vehicle1 can communicate with Host3 in Vehicle3 via IP-OBU1
in Vehicle1, IP-OBU2 in Vehicle2, and IP-OBU3 in Vehicle3 in the in Vehicle1, IP-OBU2 in Vehicle2, and IP-OBU3 in Vehicle3 in the
VANET, as shown in the figure. VANET, as shown in the figure.
In this section, the link between two vehicles is assumed to be In this section, the link between two vehicles is assumed to be
stable for single-hop wireless communication regardless of the sight stable for single-hop wireless communication regardless of the sight
relationship such as line of sight and non-line of sight, as shown in relationship, such as Line-of-Sight and Non-Line-of-Sight, as shown
Figure 3. Even in Figure 4, the three vehicles are connected to each in Figure 3. Even in Figure 4, the three vehicles are connected to
other with a linear topology, however, multihop V2V communication can each other with a linear topology, however, multihop V2V
accommodate any network topology (i.e., an arbitrary graph) over communication can accommodate any network topology (i.e., an
VANET routing protocols. arbitrary graph) over VANET routing protocols.
(*)<..................>(*)<..................>(*) (*)<..................>(*)<..................>(*)
| | | | | |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
| | | | | | | | | | | |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| |IP-OBU1| | | |IP-RSU1| | | |IP-OBU3| | | |IP-OBU1| | | |IP-RSU1| | | |IP-OBU3| |
| +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ | | +-------+ |
| ^ | | ^ | | ^ | | ^ | | ^ | | ^ |
| | |=====> | | | | | |=====> | | |=====> | | | | | |=====>
skipping to change at page 21, line 43 skipping to change at line 964
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
Vehicle1 EN1 Vehicle3 Vehicle1 EN1 Vehicle3
<----> Wired Link <....> Wireless Link ===> Moving Direction <----> Wired Link <....> Wireless Link ===> Moving Direction
(*) Antenna (*) Antenna
Figure 5: Multihop Internetworking between Two Vehicle Networks Figure 5: Multihop Internetworking between Two Vehicle Networks
via IP-RSU (V2I2V) via IP-RSU (V2I2V)
As shown in Figure 5, multihop internetworking between two vehicles As shown in Figure 5, multihop internetworking between two vehicles
is feasible via an infrastructure node (i.e., IP-RSU) with wireless is feasible via an infrastructure node (e.g., IP-RSU) with wireless
connectivity among the mobile networks of two vehicles and the fixed connectivity among the mobile networks of two vehicles and the fixed
network of an edge network (denoted as EN1) in the same VANET. For network of an edge network (denoted as EN1) in the same VANET. For
example, Host1 in Vehicle1 can communicate with Host3 in Vehicle3 via example, Host1 in Vehicle1 can communicate with Host3 in Vehicle3 via
IP-OBU1 in Vehicle1, IP-RSU1 in EN1, and IP-OBU3 in Vehicle3 in the IP-OBU1 in Vehicle1, IP-RSU1 in EN1, and IP-OBU3 in Vehicle3 in the
VANET, as shown in the figure. VANET, as shown in the figure.
For the reliability required in V2V networking, the ND optimization For the reliability required in V2V networking, the ND optimization
defined in MANET [RFC6130] [RFC7466] improves the classical IPv6 ND defined in the Mobile Ad Hoc Network (MANET) [RFC6130] [RFC7466]
in terms of tracking neighbor information with up to two hops and improves the classical IPv6 ND in terms of tracking neighbor
introducing several extensible Information Bases, which serves the information with up to two hops and introducing several extensible
MANET routing protocols such as the different versions of Optimized Information Bases. This improvement serves the MANET routing
Link State Routing Protocol (OLSR) [RFC3626] [RFC7181], Open Shortest protocols, such as the different versions of Optimized Link State
Path First (OSPF) derivatives (e.g., [RFC5614]), and Dynamic Link Routing Protocol (OLSR) [RFC3626] [RFC7181], Open Shortest Path First
Exchange Protocol (DLEP) [RFC8175] with its extensions [RFC8629] (OSPF) derivatives (e.g., [RFC5614]), and Dynamic Link Exchange
[RFC8757]. In short, the MANET ND mainly deals with maintaining Protocol (DLEP) [RFC8175] with its extensions [RFC8629] [RFC8757].
extended network neighbors to enhance the link reliability. However, In short, the MANET ND mainly deals with maintaining extended network
an ND protocol in vehicular networks shall consider more about the neighbors to enhance the link reliability. However, an ND protocol
geographical mobility information of vehicles as an important in vehicular networks shall consider more about the geographical
resource for serving various purposes to improve the reliability, mobility information of vehicles as an important resource for serving
e.g., vehicle driving safety, intelligent transportation various purposes to improve the reliability, e.g., vehicle driving
implementations, and advanced mobility services. For a more reliable safety, intelligent transportation implementations, and advanced
V2V networking, some redundancy mechanisms should be provided in L3 mobility services. For a more reliable V2V networking, some
in cases of the failure of L2. For different use cases, the optimal redundancy mechanisms should be provided in L3 in cases of the
solution to improve V2V networking reliability may vary. For failure of L2. For different use cases, the optimal solution to
example, a group of vehicles in platooning may have stabler neighbors improve V2V networking reliability may vary. For example, a group of
than freely moving vehicles, as described in Section 3.1. platooning vehicles may have stabler neighbors than freely moving
vehicles, as described in Section 3.1.
5. Problem Statement 5. Problem Statement
In order to specify protocols using the architecture mentioned in In order to specify protocols using the architecture mentioned in
Section 4.1, 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 relatively short time compared to the need to be completed in a relatively short time 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. In these cases, vehicles may not have enough time either vehicles. In these cases, vehicles may not have enough time either
to build link-layer connections with each other and may rely more on to build link-layer connections with each other and may rely more on
connections with infrastructure. In other cases, the relative speed connections with infrastructure. In other cases, the relative speed
between vehicles may be low when vehicles move toward the same between vehicles may be low when vehicles move toward the same
direction or are platooned. For those cases, vehicles can have more direction or are platooned. For those cases, vehicles can have more
time to build and maintain connections with each other. time to build and maintain connections with each other.
For safe driving, vehicles need to exchange application messages For safe driving, vehicles need to exchange application messages
every 0.5 second [NHTSA-ACAS-Report] to let drivers take an action to every 0.5 seconds [NHTSA-ACAS-Report] to let drivers take an action
avoid a dangerous situation (e.g., vehicle collision), so the IPv6 to avoid a dangerous situation (e.g., vehicle collision), so the IPv6
control plane (e.g., ND procedure and DAD) needs to support this control plane (e.g., ND procedure and DAD) needs to support this
order of magnitude for application message exchanges. Also, order of magnitude for application message exchanges. Also,
considering the communication range of DSRC (up to 1km) and 100km/h considering the communication range of DSRC (up to 1 km) and 100 km/h
as the speed limit in highway (some countries can have much higher as the speed limit on highways (some countries can have much higher
speed limit or even no limit, e.g., Germany), the lifetime of a link speed limits or even no limit, e.g., Germany), the lifetime of a link
between a vehicle and an IP-RSU is in the order of a minute (e.g., between a vehicle and an IP-RSU is in the order of a minute (e.g.,
about 72 seconds), and the lifetime of a link between two vehicles is about 72 seconds), and the lifetime of a link between two vehicles is
about a half minute. Note that if two vehicles are moving in the about a half minute. Note that if two vehicles are moving in the
opposite directions in a roadway, the relative speed of this case is opposite directions in a roadway, the relative speed of this case is
two times the relative speed of a vehicle passing through an IP-RSU. two times the relative speed of a vehicle passing through an IP-RSU.
This relative speed leads the half of the link lifetime between the This relative speed causes the lifetime of the wireless link between
vehicle and the IP-RSU. In reality, the DSRC communication range is the vehicle and the IP-RSU to be halved. In reality, the DSRC
around 500m, so the link lifetime will be a half of the maximum time. communication range is around 500 m, so the link lifetime will be
The time constraint of a wireless link between two nodes (e.g., half of the maximum time. The time constraint of a wireless link
vehicle and IP-RSU) needs to be considered because it may affect the between two nodes (e.g., vehicle and IP-RSU) needs to be considered
lifetime of a session involving the link. The lifetime of a session because it may affect the lifetime of a session involving the link.
varies depending on the session's type such as a web surfing, voice The lifetime of a session varies depending on the session's type,
call over IP, DNS query, and context-aware navigation (in such as web surfing, a voice call over IP, a DNS query, or context-
Section 3.1). Regardless of a session's type, to guide all the IPv6 aware navigation (in Section 3.1). Regardless of a session's type,
packets to their destination host(s), IP mobility should be supported to guide all the IPv6 packets to their destination host(s), IP
for the session. In a V2V scenario (e.g., context-aware navigation), mobility should be supported for the session. In a V2V scenario
the IPv6 packets of a vehicle should be delivered to relevant (e.g., context-aware navigation [CNP]), the IPv6 packets of a vehicle
vehicles efficiently (e.g., multicasting). With this observation, should be delivered to relevant vehicles efficiently (e.g.,
IPv6 protocol exchanges need to be done as short as possible to multicasting). With this observation, IPv6 protocol exchanges need
support the message exchanges of various applications in vehicular to be performed as quickly as possible to support the message
networks. exchanges of various applications in vehicular networks.
Therefore, the time constraint of a wireless link has a major impact Therefore, the time constraint of a wireless link has a major impact
on IPv6 Neighbor Discovery (ND). Mobility Management (MM) is also on IPv6 Neighbor Discovery (ND). Mobility Management (MM) is also
vulnerable to disconnections that occur before the completion of vulnerable to disconnections that occur before the completion of
identity verification and tunnel management. This is especially true identity verification and tunnel management. This is especially true
given the unreliable nature of wireless communication. Meanwhile, given the unreliable nature of wireless communication. Meanwhile,
the bandwidth of the wireless link determined by the lower layers the bandwidth of the wireless link determined by the lower layers
(i.e., link and PHY layers) can affect the transmission time of (i.e., PHY and link layers) can affect the transmission time of
control messages of the upper layers (e.g., IPv6) and the continuity control messages of the upper layers (e.g., IPv6) and the continuity
of sessions in the higher layers (e.g., IPv6, TCP, and UDP). Hence, of sessions in the higher layers (e.g., IPv6, TCP, and UDP). Hence,
the bandwidth selection according to Modulation and Coding Scheme the bandwidth selection according to the Modulation and Coding Scheme
(MCS) also affects the vehicular network connectivity. Note that (MCS) also affects the vehicular network connectivity. Note that
usually the higher bandwidth gives the shorter communication range usually the higher bandwidth gives the shorter communication range
and the higher packet error rate at the receiving side, which may and the higher packet error rate at the receiving side, which may
reduce the reliability of control message exchanges of the higher reduce the reliability of control message exchanges of the higher
layers (e.g., IPv6). This section presents key topics such as layers (e.g., IPv6). This section presents key topics, such as
neighbor discovery and mobility management for links and sessions in neighbor discovery and mobility management for links and sessions in
IPv6-based vehicular networks. Note that the detailed discussion on IPv6-based vehicular networks. Note that the detailed discussion on
the transport-layer session mobility and usage of available bandwidth the transport-layer session mobility and usage of available bandwidth
to fulfill the use cases is left as potential future work. to fulfill the use cases is left as potential future work.
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
IPv6 ND is designed for link types including point-to-point, suite. IPv6 ND is designed for link types including point-to-point,
multicast-capable (e.g., Ethernet) and Non-Broadcast Multiple Access multicast-capable (e.g., Ethernet), and Non-Broadcast Multiple Access
(NBMA). It assumes the efficient and reliable support of multicast (NBMA). It assumes the efficient and reliable support of multicast
and unicast from the link layer for various network operations such and unicast from the link layer for various network operations, such
as MAC Address Resolution (AR), DAD, MLD and Neighbor Unreachability as MAC Address Resolution (AR), DAD, MLD, and Neighbor Unreachability
Detection (NUD). Detection (NUD) [RFC4861] [RFC4862] [RFC2710] [RFC3810].
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 IPv6 addresses to run application messages with each other, they need IPv6 addresses to run
IPv6 ND. IPv6 ND.
The requirements for IPv6 ND for vehicular networks are efficient DAD The requirements for IPv6 ND for vehicular networks are efficient DAD
and NUD operations. An efficient DAD is required to reduce the and NUD operations. An efficient DAD is required to reduce the
overhead of DAD packets during a vehicle's travel in a road network, overhead of DAD packets during a vehicle's travel in a road network,
which can guarantee the uniqueness of a vehicle's global IPv6 which can guarantee the uniqueness of a vehicle's global IPv6
address. An efficient NUD is required to reduce the overhead of the address. An efficient NUD is required to reduce the overhead of the
NUD packets during a vehicle's travel in a road network, which can NUD packets during a vehicle's travel in a road network, which can
guarantee the accurate neighborhood information of a vehicle in terms guarantee the accurate neighborhood information of a vehicle in terms
of adjacent vehicles and RSUs. of adjacent vehicles and IP-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 be not valid frequently in vehicular networks. The this assumption not valid frequently in vehicular networks. The
merging and partitioning of VANETs frequently occurs in vehicular partitioning and merging of VANETs frequently occurs in vehicular
networks. This merging and partitioning should be considered for the networks. This partitioning and merging should be considered for
IPv6 ND such as IPv6 Stateless Address Autoconfiguration (SLAAC) IPv6 ND, such as IPv6 Stateless Address Autoconfiguration (SLAAC)
[RFC4862]. SLAAC is not compatible with merging and partitioning, [RFC4862]. SLAAC is not compatible with the partitioning and
and additional work is needed for ND to operate properly under those merging, and additional work is needed for ND to operate properly
circumstances. Due to the merging of VANETs, two IPv6 addresses may under those circumstances. Due to the merging of VANETs, two IPv6
conflict with each other though they were unique before the merging. addresses may conflict with each other though they were unique before
An address lookup operation may be conducted by an MA or IP-RSU (as the merging. An address lookup operation may be conducted by an MA
Registrar in RPL) to check the uniqueness of an IPv6 address that or IP-RSU (as Registrar in RPL) to check the uniqueness of an IPv6
will be configured by a vehicle as DAD. Also, the partitioning of a address that will be configured by a vehicle as DAD. Also, the
VANET may make vehicles with the same prefix be physically partitioning of a VANET may make vehicles with the same prefix be
unreachable. An address lookup operation may be conducted by an MA physically unreachable. An address lookup operation may be conducted
or IP-RSU (as Registrar in RPL) to check the existence of a vehicle by an MA or IP-RSU (as Registrar in RPL) to check the existence of a
under the network coverage of the MA or IP-RSU as NUD. Thus, SLAAC vehicle under the network coverage of the MA or IP-RSU as NUD. Thus,
needs to prevent IPv6 address duplication due to the merging of SLAAC needs to prevent IPv6 address duplication due to the merging of
VANETs, and IPv6 ND needs to detect unreachable neighboring vehicles VANETs, and IPv6 ND needs to detect unreachable neighboring vehicles
due to the partitioning of a VANET. According to the merging and due to the partitioning of a VANET. According to the partitioning
partitioning, a destination vehicle (as an IPv6 host) needs to be and merging, a destination vehicle (as an IPv6 host) needs to be
distinguished as either an on-link host or a not-onlink host even distinguished as a host that is either on-link or not on-link even
though the source vehicle can use the same prefix as the destination though the source vehicle can use the same prefix as the destination
vehicle [I-D.ietf-intarea-ippl]. vehicle [IPPL].
To efficiently prevent IPv6 address duplication due to the VANET To efficiently prevent IPv6 address duplication (due to the VANET
partitioning and merging from happening 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.
For vehicular networks with high mobility and density, DAD needs to For vehicular networks with high mobility and density, DAD needs to
be performed efficiently with minimum overhead so that the vehicles be performed efficiently with minimum overhead so that the vehicles
can exchange driving safety messages (e.g., collision avoidance and can exchange driving safety messages (e.g., collision avoidance and
accident notification) with each other with a short interval accident notification) with each other with a short interval as
suggested by NHTSA (National Highway Traffic Safety Administration) suggested by the National Highway Traffic Safety Administration
[NHTSA-ACAS-Report]. Since the partitioning and merging of vehicular (NHTSA) of the U.S. [NHTSA-ACAS-Report]. Since the partitioning and
networks may require re-perform DAD process repeatedly, the link merging of vehicular networks may require re-performing the DAD
scope of vehicles may be limited to a small area, which may delay the process repeatedly, the link scope of vehicles may be limited to a
exchange of driving safety messages. Driving safety messages can small area, which may delay the exchange of driving safety messages.
include a vehicle's mobility information (i.e., position, speed, Driving safety messages can include a vehicle's mobility information
direction, and acceleration/deceleration) that is critical to other (e.g., position, speed, direction, and acceleration/deceleration)
vehicles. The exchange interval of this message is recommended to be that is critical to other vehicles. The exchange interval of this
less than 0.5 second, which is required for a driver to avoid an message is recommended to be less than 0.5 seconds, which is required
emergency situation, such as a rear-end crash. for a driver to avoid an emergency situation, such as a rear-end
crash.
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
vehicle density. For example, the NA interval needs to be and 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 position relative to its neighboring
considering the collision probability with the NA messages sent by vehicles in a stable way, considering the collision probability with
other vehicles. The ND time-related parameters can be an operational the NA messages sent by other vehicles. The ND time-related
setting or an optimization point particularly for vehicular networks. parameters can be an operational setting or an optimization point
Note that the link-scope multicast messages in ND protocol may cause particularly for vehicular networks. Note that the link-scope
the performance issue in vehicular networks. [RFC9119] suggests multicast messages in the ND protocol may cause a performance issue
several optimization approaches for the issue. in vehicular networks. [RFC9119] suggests several optimization
approaches for the issue.
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. IPv6 ND needs to work to delay-bounded data delivery is critical. IPv6 ND needs to work to
support those IPv6-based safety applications efficiently. support those IPv6-based safety applications efficiently.
[I-D.jeong-ipwave-vehicular-neighbor-discovery] introduces a [VEHICULAR-ND] introduces a Vehicular Neighbor Discovery (VND)
Vehicular Neighbor Discovery (VND) process as an extension of IPv6 ND process as an extension of IPv6 ND for IP-based vehicular networks.
for IP-based vehicular networks.
From the interoperability point of view, in IPv6-based vehicular From the interoperability point of view, in IPv6-based vehicular
networking, IPv6 ND should have minimum changes with the legacy IPv6 networking, IPv6 ND should have minimum changes from the legacy IPv6
ND used in the Internet, including DAD and NUD operations, so that ND used in the Internet, including DAD and NUD operations, so that
IPv6-based vehicular networks can be seamlessly connected to other IPv6-based vehicular networks can be seamlessly connected to other
intelligent transportation elements (e.g., traffic signals, intelligent transportation elements (e.g., traffic signals,
pedestrian wearable devices, electric scooters, and bus stops) that pedestrian wearable devices, electric scooters, and bus stops) that
use the standard IPv6 network settings. use the standard IPv6 network settings.
5.1.1. Link Model 5.1.1. Link Model
A subnet model for a vehicular network needs to facilitate the A subnet model for a vehicular network needs to facilitate
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 subnet model allows vehicles with the same prefix to IP-RSUs. This subnet 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. [WIRELESS-ND] introduces other
[I-D.thubert-6man-ipv6-over-wireless] introduces other issues in an issues in an IPv6 subnet model.
IPv6 subnet model.
IPv6 protocols work under certain assumptions that do not necessarily IPv6 protocols work under certain assumptions that do not necessarily
hold for vehicular wireless access link types [VIP-WAVE][RFC5889]. hold for vehicular wireless access link types [VIP-WAVE] [RFC5889].
For instance, some IPv6 protocols such as NUD [RFC4861] and MIPv6 For instance, some IPv6 protocols, such as NUD [RFC4861] and MIPv6
[RFC6275] assume symmetry in the connectivity among neighboring [RFC6275], assume symmetry in the connectivity among neighboring
interfaces. However, radio interference and different levels of interfaces. However, radio interference and different levels of
transmission power may cause asymmetric links to appear in vehicular transmission power may cause asymmetric links to appear in vehicular
wireless links [RFC6250]. As a result, a new vehicular link model wireless links [RFC6250]. As a result, a new vehicular link model
needs to consider the asymmetry of dynamically changing vehicular needs to consider the asymmetry of dynamically changing vehicular
wireless links. 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, unique-local, different scopes that are expected from the link-local, unique-local,
and global types of IPv6 addresses. In an IPv6 link, it is defined and global types of IPv6 addresses. In an IPv6 link, it is defined
that all interfaces which are configured with the same subnet prefix that all interfaces that are configured with the same subnet prefix
and with on-link bit set can communicate with each other on an IPv6 and with the on-link bit set can communicate with each other on an
link. However, the vehicular link model needs to define the IPv6 link. However, the vehicular link model needs to define the
relationship between a link and a prefix, considering the dynamics of relationship between a link and a prefix, considering the dynamics of
wireless links and the characteristics of VANET. wireless links and the characteristics of VANET.
A VANET can have a single link between each vehicle pair within A VANET can have a single link between each vehicle pair within the
wireless communication range, as shown in Figure 4. When two wireless communication range, as shown in Figure 4. 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 (or an IPv6 ULA other. Suppose that a global-scope IPv6 prefix (or an IPv6 ULA
prefix) is assigned to VANETs in vehicular networks. Considering prefix) is assigned to VANETs in vehicular networks. Considering
that two vehicles in the same VANET configure their IPv6 addresses that two vehicles in the same VANET configure their IPv6 addresses
with the same IPv6 prefix, if they are not in one hop (that is, they with the same IPv6 prefix, if they are not connected in one hop (that
have the multihop network connectivity between them), then they may is, they have multihop network connectivity between them), then they
not be able to communicate with each other. Thus, in this case, the may not be able to communicate with each other. Thus, in this case,
concept of an on-link IPv6 prefix does not hold because two vehicles the concept of an on-link IPv6 prefix does not hold because two
with the same on-link IPv6 prefix cannot communicate directly with vehicles with the same on-link IPv6 prefix cannot communicate
each other. Also, when two vehicles are located in two different directly with each other. Also, when two vehicles are located in two
VANETs with the same IPv6 prefix, they cannot communicate with each different VANETs with the same IPv6 prefix, they cannot communicate
other. When these two VANETs converge to one VANET, the two vehicles with each other. On the other hand, when these two VANETs converge
can communicate with each other in a multihop fashion, for example, to one VANET, the two vehicles can communicate with each other in a
when they are Vehicle1 and Vehicle3, as shown in Figure 4. multihop fashion, for example, when they are Vehicle1 and Vehicle3,
as shown in Figure 4.
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 a prefix
link prefix and not-onlink prefix according to the network topology that is on-link and a prefix that is not on-link according to the
of vehicles such as a one-hop reachable network and a multihop network topology of vehicles, such as a one-hop reachable network and
reachable network (or partitioned networks). If the vehicles with a multihop reachable network (or partitioned networks). If the
the same prefix are reachable from each other in one hop, the prefix vehicles with the same prefix are reachable from each other in one
should be on-link. On the other hand, if some of the vehicles with hop, the prefix should be on-link. On the other hand, if some of the
the same prefix are not reachable from each other in one hop due to vehicles with the same prefix are not reachable from each other in
either the multihop topology in the VANET or multiple partitions, the one hop due to either the multihop topology in the VANET or multiple
prefix should be not-onlink. In most cases in vehicular networks, partitions, the prefix should not be on-link. In most cases in
due to the partitioning and merging of VANETs, and the multihop vehicular networks, due to the partitioning and merging of VANETs and
network topology of VANETS, not-onlink prefixes will be used for the multihop network topology of VANETs, prefixes that are not on-
vehicles as default. link will be used for vehicles as default.
The vehicular link model needs to support 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 (or the same IPv6 ULA prefix) are connected in one hop or prefix (or the same IPv6 ULA prefix) are connected in one hop or
multiple hops. It also needs to support the multihop routing in multiple hops. It also needs to support the multihop routing in
multiple connected VANETs through infrastructure nodes (e.g., IP-RSU) multiple connected VANETs through infrastructure nodes (e.g., IP-RSU)
where they are connected to the infrastructure. For example, in where they are connected to the infrastructure. For example, in
Figure 1, suppose that Vehicle1, Vehicle2, and Vehicle3 are Figure 1, suppose that Vehicle1, Vehicle2, and Vehicle3 are
configured with their IPv6 addresses based on the same global-scope configured with their IPv6 addresses based on the same global-scope
IPv6 prefix. Vehicle1 and Vehicle3 can also communicate with each IPv6 prefix. Vehicle1 and Vehicle3 can also communicate with each
other via either multihop V2V or multihop V2I2V. When Vehicle1 and other via either multihop V2V or multihop V2I2V. When Vehicle1 and
Vehicle3 are connected in a VANET, it will be more efficient for them Vehicle3 are connected in a VANET, it will be more efficient for them
to communicate with each other directly via VANET rather than to communicate with each other directly via VANET rather than
indirectly via IP-RSUs. On the other hand, when Vehicle1 and indirectly via IP-RSUs. On the other hand, when Vehicle1 and
Vehicle3 are far away from direct communication range in separate Vehicle3 are farther apart than the direct communication range in two
VANETs and under two different IP-RSUs, they can communicate with separate VANETs and under two different IP-RSUs, they can communicate
each other through the relay of IP-RSUs via V2I2V. Thus, two with each other through the relay of IP-RSUs via V2I2V. Thus, the
separate VANETs can merge into one network via IP-RSU(s). Also, two separate VANETs can merge into one network via IP-RSU(s). Also,
newly arriving vehicles can merge two separate VANETs into one VANET newly arriving vehicles can merge the two separate VANETs into one
if they can play the role of a relay node for those VANETs. VANET if they can play the role of a relay node for those VANETs.
Thus, in IPv6-based vehicular networking, the vehicular link model Thus, in IPv6-based vehicular networking, the vehicular link model
should have minimum changes for interoperability with standard IPv6 should have minimum changes for interoperability with standard IPv6
links efficiently to support IPv6 DAD, MLD and NUD operations. links efficiently to support IPv6 DAD, MLD, 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 to some extent the privacy of pseudonym of a MAC address can protect to some extent the privacy of
a 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].
Note that [MAC-ADD-RAN] discusses more about MAC address
Note that [I-D.ietf-madinas-mac-address-randomization] discusses more randomization, and [RCM-USE-CASES] describes several use cases for
about MAC address randomization, and [I-D.ietf-madinas-use-cases] MAC address randomization.
describes several use cases for MAC address randomization.
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 DAD procedure. checked through a DAD procedure.
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 Mobile Ad Hoc Networks (MANET) routing protocol may RSUs, a vehicular Mobile Ad Hoc Networks (MANET) routing protocol 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 [RFC9119]. control traffic overhead [RFC9119].
A routing protocol for a 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 a VANET with a dynamic network topology routing information in a VANET with a dynamic network topology
because the IPv6 ND is used to check the neighborhood of each because IPv6 ND is used to check the neighborhood of each vehicle.
vehicle. Thus, the vehicular routing needs to take advantage of the Thus, the vehicular routing needs to take advantage of IPv6 ND to
IPv6 ND to minimize its control overhead. minimize its control overhead.
RPL [RFC6550] defines a routing protocol for low-power and lossy RPL [RFC6550] defines a routing LLN protocol, which constructs and
networks, which constructs and maintains Destination-Oriented maintains Destination-Oriented Directed Acyclic Graphs (DODAGs)
Directed Acyclic Graphs (DODAGs) optimized by an Objective Function optimized by an Objective Function (OF). A defined OF provides route
(OF). A defined OF provides route selection and optimization within selection and optimization within an RPL topology. The RPL nodes use
an RPL topology. The RPL nodes use an anisotropic Distance Vector an anisotropic Distance Vector (DV) approach to form a DODAG by
(DV) approach to form a DODAG by discovering and aggressively discovering and aggressively maintaining the upward default route
maintaining the upward default route toward the root of the DODAG. toward the root of the DODAG. Downward routes follow the same DODAG,
Downward routes follow the same DODAG, with lazy maintenance and with lazy maintenance and stretched peer-to-peer (P2P) routing in the
stretched Peer-to-Peer (P2P) routing in the so-called storing mode. so-called storing mode. It is well-designed to reduce the
It is well-designed to reduce the topological knowledge and routing topological knowledge and routing state that needs to be exchanged.
state that needs to be exchanged. As a result, the routing protocol As a result, the routing protocol overhead is minimized, which allows
overhead is minimized, which allows either highly constrained stable either highly constrained stable networks or less constrained, highly
networks or less constrained, highly dynamic networks. Refer to dynamic networks. Refer to Appendix B for the detailed description
Appendix B for the detailed description of RPL for multihop V2X of RPL for multihop V2X networking.
networking.
An address registration extension for 6LoWPAN (IPv6 over Low-Power An address registration extension for 6LoWPAN (IPv6 over Low-Power
Wireless Personal Area Network) in [RFC8505] can support light-weight Wireless Personal Area Network) in [RFC8505] can support light-weight
mobility for nodes moving through different parents. [RFC8505], as mobility for nodes moving through different parents. The extension
opposed to [RFC4861], is stateful and proactively installs the ND described in [RFC8505] is stateful and proactively installs the ND
cache entries, which saves broadcasts and provides deterministic cache entries; this saves broadcasts and provides deterministic
presence information for IPv6 addresses. Mainly it updates the presence information for IPv6 addresses. Mainly, it updates the
Address Registration Option (ARO) of ND defined in [RFC6775] to Address Registration Option (ARO) of ND defined in [RFC6775] to
include a status field that can indicate the movement of a node and include a status field (which can indicate the movement of a node)
optionally a Transaction ID (TID) field, i.e., a sequence number that and optionally a Transaction ID (TID) field (which is a sequence
can be used to determine the most recent location of a node. Thus, number that can be used to determine the most recent location of a
RPL can use the information provided by the Extended ARO (EARO) node). Thus, RPL can use the information provided by the Extended
defined in [RFC8505] to deal with a certain level of node mobility. ARO (EARO) defined in [RFC8505] to deal with a certain level of node
When a leaf node moves to the coverage of another parent node, it mobility. When a leaf node moves to the coverage of another parent
should de-register its addresses to the previous parent node and node, it should de-register its addresses with the previous parent
register itself with a new parent node along with an incremented TID. node and register itself with a new parent node along with an
incremented TID.
RPL can be used in IPv6-based vehicular networks, but it is primarily RPL can be used in IPv6-based vehicular networks, but it is primarily
designed for low-power networks, which puts energy efficiency first. designed for low-power networks, which puts energy efficiency first.
For using it in IPv6-based vehicular networks, there have not been For using it in IPv6-based vehicular networks, there have not been
actual experiences and practical implementations, though it was actual experiences and practical implementations, though it was
tested in IoT low-power and lossy networks (LLN) scenarios. Another tested in IoT Low-Power and Lossy Network (LLN) scenarios. Another
concern is that RPL may generate excessive topology discovery concern is that RPL may generate excessive topology discovery
messages in a highly moving environment such as vehicular networks. messages in a highly moving environment, such as vehicular networks.
This issue can be an operational or optimization point for a This issue can be an operational or optimization point for a
practitioner. practitioner.
Moreover, due to bandwidth and energy constraints, RPL does not Moreover, due to bandwidth and energy constraints, RPL does not
suggest using a proactive mechanism (e.g., keepalive) to maintain suggest using a proactive mechanism (e.g., keepalive) to maintain
accurate routing adjacencies such as Bidirectional Forwarding accurate routing adjacencies, such as Bidirectional Forwarding
Detection [RFC5881] and MANET Neighborhood Discovery Protocol Detection [RFC5881] and MANET Neighborhood Discovery Protocol
[RFC6130]. As a result, due to the mobility of vehicles, network [RFC6130]. As a result, due to the mobility of vehicles, network
fragmentation may not be detected quickly and the routing of packets fragmentation may not be detected quickly, and the routing of packets
between vehicles or between a vehicle and an infrastructure node may between vehicles or between a vehicle and an infrastructure node may
fail. fail.
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
points requires efficient mobility management including location endpoints requires efficient mobility management including location
management and handover. Most vehicles are equipped with a GNSS management and handover. Most vehicles are equipped with a GNSS
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 GNSS receiver may not provide vehicles smartphone app. Note that the GNSS 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 or a tunnel. The location precision can be improved building area or a tunnel. The location precision can be improved
with assistance of the IP-RSUs or a cellular system with a GNSS with assistance of the IP-RSUs or a cellular system with a GNSS
receiver for location information. receiver for location information.
With a GNSS navigator, efficient mobility management can be performed With a GNSS navigator, efficient mobility management can be performed
with the help of vehicles periodically reporting their current with the help of vehicles periodically reporting their current
position and trajectory (i.e., navigation path) to the vehicular position and trajectory (i.e., navigation path) to the vehicular
infrastructure (having IP-RSUs and an MA in TCC). This vehicular infrastructure (having IP-RSUs and an MA in TCC). This vehicular
infrastructure can predict the future positions of the vehicles from infrastructure can predict the future positions of the vehicles from
their mobility information (i.e., the current position, speed, their mobility information (e.g., the current position, speed,
direction, and trajectory) for efficient mobility management (e.g., direction, and trajectory) for efficient mobility management (e.g.,
proactive handover). For a better proactive handover, link-layer proactive handover). For a better proactive handover, link-layer
parameters, such as the signal strength of a link-layer frame (e.g., parameters, such as the signal strength of a link-layer frame (e.g.,
Received Channel Power Indicator (RCPI) [VIP-WAVE]), can be used to Received Channel Power Indicator (RCPI) [VIP-WAVE]), can be used to
determine the moment of a handover between IP-RSUs along with determine the moment of a handover between IP-RSUs along with
mobility information. 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
for the sake of the vehicle. the sake of the vehicle.
For a mobility management scheme in a domain, where the wireless For a mobility management scheme in a domain, where the wireless
subnets of multiple IP-RSUs share the same prefix, an efficient subnets of multiple IP-RSUs share the same prefix, an efficient
vehicular-network-wide DAD is required. On the other hand, for a vehicular-network-wide DAD is required. On the other hand, for a
mobility management scheme with a unique prefix per mobile node mobility management scheme with a unique prefix per mobile node
(e.g., PMIPv6 [RFC5213]), DAD is not required because the IPv6 (e.g., PMIPv6 [RFC5213]), DAD is not required because the IPv6
address of a vehicle's external wireless interface is guaranteed to address of a vehicle's external wireless interface is guaranteed to
be unique. There is a trade-off between the prefix usage efficiency be unique. There is a trade-off between the prefix usage efficiency
and DAD overhead. Thus, the IPv6 address autoconfiguration for and DAD overhead. Thus, the IPv6 address autoconfiguration for
vehicular networks needs to consider this trade-off to support vehicular networks needs to consider this trade-off to support
efficient mobility management. efficient mobility management.
Even though the SLAAC with classic ND costs a DAD during mobility Even though SLAAC with classic ND costs DAD overhead during mobility
management, the SLAAC with [RFC8505] and/or AERO/OMNI do not cost a management, SLAAC with the registration extension specified in
DAD. SLAAC for vehicular networks needs to consider the minimization [RFC8505] and/or with AERO/OMNI does not cost DAD overhead. SLAAC
of the cost of DAD with the help of an infrastructure node (e.g., IP- for vehicular networks needs to consider the minimization of the cost
RSU and MA). Using an infrastructure prefix over VANET allows direct of DAD with the help of an infrastructure node (e.g., IP-RSU and MA).
routability to the Internet through the multihop V2I toward an IP- Using an infrastructure prefix over VANET allows direct routability
RSU. On the other hand, a BYOA does not allow such direct to the Internet through the multihop V2I toward an IP-RSU. On the
routability to the Internet since the BYOA is not topologically other hand, a BYOA does not allow such direct routability to the
correct, that is, not routable in the Internet. In addition, a Internet since the BYOA is not topologically correct, that is, not
vehicle configured with a BYOA needs a tunnel home (e.g., IP-RSU) routable in the Internet. In addition, a vehicle configured with a
connected to the Internet, and the vehicle needs to know which BYOA needs a tunnel home (e.g., IP-RSU) connected to the Internet,
neighboring vehicle is reachable inside the VANET toward the tunnel and the vehicle needs to know which neighboring vehicle is reachable
home. There is non-negligible control overhead to set up and inside the VANET toward the tunnel home. There is non-negligible
maintain routes to such a tunnel home [RFC4888] over the VANET. control overhead to set up and maintain routes to such a tunnel home
[RFC4888] over the VANET.
For the case of a multihomed network, a vehicle can follow the first- For the case of a multihomed network, a vehicle can follow the first-
hop router selection rule described in [RFC8028]. For example, an hop router selection rule described in [RFC8028]. For example, an
IP-OBU inside a vehicle may connect to an IP-RSU that has multiple IP-OBU inside a vehicle may connect to an IP-RSU that has multiple
routers behind. In this scenario, because the IP-OBU can have routers behind. In this scenario, because the IP-OBU can have
multiple prefixes from those routers, the default router selection, multiple prefixes from those routers, the default router selection,
source address selection, and packet redirect process should follow source address selection, and packet redirect process should follow
the guidelines in [RFC8028]. That is, the vehicle should select its the guidelines in [RFC8028]. That is, the vehicle should select its
default router for each prefix by preferring the router that default router for each prefix by preferring the router that
advertised the prefix. advertised the prefix.
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], PMIPv6 [RFC5213], and for mobility management as in MIPv6 [RFC6275], PMIPv6 [RFC5213], and
NEMO [RFC3963], so the TCC (or an MA inside the TCC) maintains the NEMO [RFC3963], so the TCC (or an MA inside the TCC) maintains the
mobility information of vehicles for location management. Also, in mobility information of vehicles for location management. Also, in
vehicular networks, asymmetric links sometimes exist and must be vehicular networks, asymmetric links sometimes exist and must be
considered for wireless communications such as V2V and V2I. considered for wireless communications, such as V2V and V2I.
[I-D.jeong-ipwave-vehicular-mobility-management] discusses a [VEHICULAR-MM] discusses a Vehicular Mobility Management (VMM) scheme
Vehicular Mobility Management (VMM) scheme to proactively do handover to proactively do handover for vehicles.
for vehicles.
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. Also, in their mobility information and link-layer information. Also, in
IPv6-based vehicular networking, IPv6 mobility management should have IPv6-based vehicular networking, IPv6 mobility management should have
minimum changes for the interoperability with the legacy IPv6 minimum changes for the interoperability with the legacy IPv6
mobility management schemes such as PMIPv6, DMM, LISP, and AERO. 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. Security and privacy are paramount in V2I, V2V, and V2X networking. Security and privacy are paramount in V2I, V2V, and V2X
networking along with neighbor discovery and mobility management. networking along with neighbor discovery and mobility management.
Vehicles and infrastructure must be authenticated to each other by a Vehicles and infrastructure must be authenticated to each other by a
password, a key, and/or a fingerprint in order to participate in password, a key, and/or a fingerprint in order to participate in
vehicular networking. For the authentication in vehicular networks, vehicular networking. For the authentication in vehicular networks,
vehicular cloud needs to support a Public Key Infrastructure (PKI) the Vehicular Cloud needs to support a Public Key Infrastructure
efficiently, as either a dedicated or a co-located component inside a (PKI) efficiently, as either a dedicated or a co-located component
TCC. To provide safe interaction between vehicles or between a inside a TCC. To provide safe interaction between vehicles or
vehicle and infrastructure, only authenticated nodes (i.e., vehicle between a vehicle and infrastructure, only authenticated nodes (i.e.,
and infrastructure node) can participate in vehicular networks. vehicle and infrastructure nodes) can participate in vehicular
Also, in-vehicle devices (e.g., ECU) and a driver/passenger's mobile networks. Also, in-vehicle devices (e.g., ECUs) and a driver/
devices (e.g., smartphone and tablet PC) in a vehicle need to passenger's mobile devices (e.g., smartphones and tablet PCs) in a
communicate with other in-vehicle devices and another driver/ vehicle need to securely communicate with other in-vehicle devices,
passenger's mobile devices in another vehicle, or other servers another driver/passenger's mobile devices in another vehicle, or
behind an IP-RSU securely. Even though a vehicle is perfectly other servers behind an IP-RSU. Even though a vehicle is perfectly
authenticated by another entity and legitimate to use the data authenticated by another entity and legitimate to use the data
generated by another vehicle, it may be hacked for running malicious generated by another vehicle, it may be hacked by malicious
applications to track and collect its and other vehicles' applications that track and collect its and other vehicles'
information. In this case, an attack mitigation process may be information. In this case, an attack mitigation process may be
required to reduce the aftermath of malicious behaviors. Note that required to reduce the aftermath of malicious behaviors. Note that
when driver/passenger's mobile devices are connected to a vehicle's when a driver/passenger's mobile devices are connected to a vehicle's
internal network, the vehicle may be more vulnerable to possible internal network, the vehicle may be more vulnerable to possible
attacks from external networks due to the exposure of its in-flight attacks from external networks due to the exposure of its in-flight
traffic packets. [I-D.jeong-ipwave-security-privacy] discusses traffic packets. [SEC-PRIV] discusses several types of threats for
several types of threats for Vehicular Security and Privacy (VSP). Vehicular Security and Privacy (VSP).
For secure V2I communication, a secure channel (e.g., IPsec) between 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., 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 2 IP-RSU) in an EN needs to be established, as shown in Figure 2
[RFC4301][RFC4302] [RFC4303][RFC4308] [RFC7296]. Also, for secure [RFC4301] [RFC4302] [RFC4303] [RFC4308] [RFC7296]. Also, for secure
V2V communication, a secure channel (e.g., IPsec) between a mobile 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) router (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. in another vehicle needs to be established, as shown in Figure 3.
For secure V2I/V2V communication, an element in a vehicle (e.g., an For secure V2I/V2V communication, an element in a vehicle (e.g., an
in-vehicle device and a driver/passenger's mobile device) needs to in-vehicle device and a driver/passenger's mobile device) needs to
establish a secure connection (e.g., TLS) with another element in establish a secure connection (e.g., TLS) with another element in
another vehicle or another element in a vehicular cloud (e.g., a another vehicle or another element in a Vehicular Cloud (e.g., a
server). Note that any key management approach can be used for the server). Note that any key management approach can be used for the
secure communication, and particularly for IPv6-based vehicular secure communication, and particularly for IPv6-based vehicular
networks, a new or enhanced key management approach resilient to networks, a new or enhanced key management approach resilient to
wireless networks is required. wireless networks is required.
IEEE 1609.2 [WAVE-1609.2] specifies security services for IEEE Std 1609.2 [WAVE-1609.2] specifies security services for
applications and management messages, but this WAVE specification is applications and management messages, but this WAVE specification is
optional. Thus, if the link layer does not support the security of a optional. Thus, if the link layer does not support the security of a
WAVE frame, either the network layer or the transport layer needs to WAVE frame, either the network layer or the transport layer needs to
support security services for the WAVE frames. support security services for the WAVE frame.
6.1. Security Threats in Neighbor Discovery 6.1. Security Threats in Neighbor Discovery
For the classical IPv6 ND (i.e., the legacy ND), DAD is required to For the classical IPv6 ND (i.e., the legacy ND), DAD is required to
ensure the uniqueness of the IPv6 address of a vehicle's wireless ensure the uniqueness of the IPv6 address of a vehicle's wireless
interface. This DAD can be used as a flooding attack that uses the interface. This DAD can be used as a flooding attack that uses the
DAD-related ND packets disseminated over the VANET or vehicular DAD-related ND packets disseminated over the VANET or vehicular
networks. [RFC6959] introduces threats enabled by IP source address networks. [RFC6959] introduces threats enabled by IP source address
spoofing. This possibility indicates that vehicles and IP-RSUs need spoofing. This possibility indicates that vehicles and IP-RSUs need
to filter out suspicious ND traffic in advance. [RFC8928] introduces to filter out suspicious ND traffic in advance. [RFC8928] introduces
a mechanism that protects the ownership of an address for 6loWPAN ND a mechanism that protects the ownership of an address for 6LoWPAN ND
from address theft and impersonation attacks. Based on the SEND from address theft and impersonation attacks. Based on the SEND
[RFC3971] mechanism, the authentication for routers (i.e., IP-RSUs) mechanism [RFC3971], the authentication for routers (i.e., IP-RSUs)
can be conducted by only selecting an IP-RSU that has a certification can be conducted by only selecting an IP-RSU that has a certification
path toward trusted parties. For authenticating other vehicles, path toward trusted parties. For authenticating other vehicles,
cryptographically generated addresses (CGA) can be used to verify the Cryptographically Generated Addresses (CGAs) can be used to verify
true owner of a received ND message, which requires using the CGA ND the true owner of a received ND message, which requires using the CGA
option in the ND protocol. This CGA can protect vehicles against DAD ND option in the ND protocol. This CGA can protect vehicles against
flooding by DAD filtering based on the verification for the true DAD flooding by DAD filtering based on the verification for the true
owner of the received DAD message. For a general protection of the owner of the received DAD message. For a general protection of the
ND mechanism, the RSA Signature ND option can also be used to protect ND mechanism, the RSA Signature ND option can also be used to protect
the integrity of the messages by public key signatures. For a more the integrity of the messages by public key signatures. For a more
advanced authentication mechanism, a distributed blockchain-based advanced authentication mechanism, a distributed blockchain-based
approach [Vehicular-BlockChain] can be used. However, for a scenario approach [Vehicular-BlockChain] can be used. However, for a scenario
where a trustable router or an authentication path cannot be where a trustable router or an authentication path cannot be
obtained, it is desirable to find a solution in which vehicles and obtained, it is desirable to find a solution in which vehicles and
infrastructures can authenticate each other without any support from infrastructure nodes can authenticate each other without any support
a third party. from a third party.
When applying the classical IPv6 ND process to VANET, one of the When applying the classical IPv6 ND process to VANET, one of the
security issues is that an IP-RSU (or an IP-OBU) as a router may security issues is that an IP-RSU (or IP-OBU) as a router may receive
receive deliberate or accidental DoS attacks from network scans that deliberate or accidental DoS attacks from network scans that probe
probe devices on a VANET. In this scenario, the IP-RSU can be devices on a VANET. In this scenario, the IP-RSU (or IP-OBU) can be
overwhelmed for processing the network scan requests so that the overwhelmed by processing the network scan requests so that the
capacity and resources of IP-RSU are exhausted, causing the failure capacity and resources of the IP-RSU (or IP-OBU) are exhausted,
of receiving normal ND messages from other hosts for network address causing the failure of receiving normal ND messages from other hosts
resolution. [RFC6583] describes more about the operational problems for network address resolution. [RFC6583] describes more about the
in the classical IPv6 ND mechanism that can be vulnerable to operational problems in the classical IPv6 ND mechanism that can be
deliberate or accidental DoS attacks and suggests several vulnerable to deliberate or accidental DoS attacks and suggests
implementation guidelines and operational mitigation techniques for several implementation guidelines and operational mitigation
those problems. Nevertheless, for running IPv6 ND in VANET, those techniques for those problems. Nevertheless, for running IPv6 ND in
issues can be more acute since the movements of vehicles can be so VANET, those issues can be acuter since the movements of vehicles can
diverse that it leaves a large room for rogue behaviors, and the be so diverse that there is a wider opportunity for rogue behaviors,
failure of networking among vehicles may cause grave consequences. and the failure of networking among vehicles may lead to grave
consequences.
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 that are controlled by
hackers. For safe driving applications (e.g., context-aware hackers. For safe driving applications (e.g., context-aware
navigation, cooperative adaptive cruise control, and platooning), as navigation, cooperative adaptive cruise control, and platooning), as
explained in Section 3.1, the cooperative action among vehicles is 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) for disturbing safe driving. (e.g., location, speed, and direction) for disturbing safe driving.
For example, a Sybil attack, which tries to confuse a vehicle with For example, a Sybil attack, which tries to confuse a vehicle with
multiple false identities, may disturb a vehicle from taking a safe multiple false identities, may disturb a vehicle from taking a safe
maneuver. Since cybersecurity issues in vehicular networks may cause maneuver. Since cybersecurity issues in vehicular networks may cause
physical vehicle safety issues, it may be necessary to consider those physical vehicle safety issues, it may be necessary to consider those
physical security concerns when designing protocols in IPWAVE. physical safety concerns when designing protocols in IPWAVE.
To identify malicious vehicles among vehicles, an authentication To identify malicious vehicles among vehicles, an authentication
method may be required. A Vehicle Identification Number (VIN) (or a method may be required. A Vehicle Identification Number (VIN) (or a
vehicle manufacturer certificate) and a user certificate (e.g., X.509 vehicle manufacturer certificate) and a user certificate (e.g., X.509
certificate [RFC5280]) along with an in-vehicle device's identifier certificate [RFC5280]) along with an in-vehicle device's identifier
generation can be used to efficiently authenticate a vehicle or its generation can be used to efficiently authenticate a vehicle or its
driver (having a user certificate) through a road infrastructure node driver (having a user certificate) through a road infrastructure node
(e.g., IP-RSU) connected to an authentication server in the vehicular (e.g., IP-RSU) connected to an authentication server in the Vehicular
cloud. This authentication can be used to identify the vehicle that Cloud. This authentication can be used to identify the vehicle that
will communicate with an infrastructure node or another vehicle. In will communicate with an infrastructure node or another vehicle. In
the case where a vehicle has an internal network (called Moving the case where a vehicle has an internal network (called a mobile
Network) and elements in the network (e.g., in-vehicle devices and a network) and elements in the network (e.g., in-vehicle devices and a
user's mobile devices), as shown in Figure 2, the elements in the user's mobile devices), as shown in Figure 2, the elements in the
network need to be authenticated individually for safe network need to be authenticated individually for safe
authentication. Also, Transport Layer Security (TLS) certificates authentication. Also, Transport Layer Security (TLS) certificates
[RFC8446][RFC5280] can be used for an element's authentication to [RFC8446] [RFC5280] can be used for an element's authentication to
allow secure E2E vehicular communications between an element in a allow secure E2E vehicular communications between an element in a
vehicle and another element in a server in a vehicular cloud, or vehicle and another element in a server in a Vehicular Cloud or
between an element in a vehicle and another element in another between an element in a vehicle and another element in another
vehicle. vehicle.
6.2. Security Threats in Mobility Management 6.2. Security Threats in Mobility Management
For mobility management, a malicious vehicle can construct multiple For mobility management, a malicious vehicle can construct multiple
virtual bogus vehicles, and register them with IP-RSUs and MA. This virtual bogus vehicles and register them with IP-RSUs and MAs. This
registration makes the IP-RSUs and MA waste their resources. The IP- registration makes the IP-RSUs and MAs waste their resources. The
RSUs and MA need to determine whether a vehicle is genuine or bogus IP-RSUs and MAs need to determine whether a vehicle is genuine or
in mobility management. Also, the confidentiality of control packets bogus in mobility management. Also, for the confidentiality of
and data packets among IP-RSUs and MA, the E2E paths (e.g., tunnels) control packets and data packets between IP-RSUs and MAs, the E2E
need to be protected by secure communication channels. In addition, paths (e.g., tunnels) need to be protected by secure communication
to prevent bogus IP-RSUs and MA from interfering with the IPv6 channels. In addition, to prevent bogus IP-RSUs and MAs from
mobility of vehicles, mutual authentication among them needs to be interfering with the IPv6 mobility of vehicles, mutual authentication
performed by certificates (e.g., TLS certificate). among the IP-RSUs, MAs, and vehicles needs to be performed by
certificates (e.g., TLS certificate).
6.3. Other Threats 6.3. Other Threats
For the setup of a secure channel over IPsec or TLS, the multihop V2I For the setup of a secure channel over IPsec or TLS, the multihop V2I
communications over DSRC or 5G V2X (or LTE V2X) is required in a communications over DSRC or 5G V2X (or LTE V2X) is required on a
highway. In this case, multiple intermediate vehicles as relay nodes highway. In this case, multiple intermediate vehicles as relay nodes
can help to forward association and authentication messages toward an can help to forward association and authentication messages toward an
IP-RSU (gNodeB or eNodeB) connected to an authentication server in IP-RSU (or gNodeB/eNodeB) connected to an authentication server in
the vehicular cloud. In this kind of process, the authentication the Vehicular Cloud. In this kind of process, the authentication
messages forwarded by each vehicle can be delayed or lost, which may messages forwarded by each vehicle can be delayed or lost, which may
increase the construction time of a connection or some vehicles may increase the construction time of a connection or cause some vehicles
not be able to be authenticated. to not be able to be authenticated.
Even though vehicles can be authenticated with valid certificates by Even though vehicles can be authenticated with valid certificates by
an authentication server in the vehicular cloud, the authenticated an authentication server in the Vehicular Cloud, the authenticated
vehicles may harm other vehicles. To deal with this kind of security vehicles may harm other vehicles. To deal with this kind of security
issue, for monitoring suspicious behaviors, vehicles' communication issue, for monitoring suspicious behaviors, vehicles' communication
activities can be recorded in either a centralized approach through a activities can be recorded in either a centralized approach through a
logging server (e.g., TCC) in the vehicular cloud or a decentralized logging server (e.g., TCC) in the Vehicular Cloud or a decentralized
approach (e.g., an edge computing device and blockchain [Bitcoin]) by approach (e.g., an ECD and blockchain [Bitcoin]) by the help of other
the help of other vehicles and infrastructure. vehicles and infrastructure.
There are trade-offs between centralized and decentralized approaches There are trade-offs between centralized and decentralized approaches
in logging for vehicles' behaviors (e.g., location, speed, direction, in logging of vehicles' behaviors (e.g., location, speed, direction,
acceleration, deceleration, and lane change) and communication acceleration/deceleration, and lane change) and communication
activities (e.g., transmission time, reception time, and packet types activities (e.g., transmission time, reception time, and packet
such as TCP, UDP, SCTP, QUIC, HTTP, and HTTPS). A centralized types, such as TCP, UDP, SCTP, QUIC, HTTP, and HTTPS). A centralized
approach is more efficient than a decentralized approach in terms of approach is more efficient than a decentralized approach in terms of
logging data collection and processing in a central server in the log data collection and processing in a central server in the
vehicular cloud. However, the centralized approach may cause a Vehicular Cloud. However, the centralized approach may cause a
higher delay than a decentralized approach in terms of the analysis higher delay than a decentralized approach in terms of the analysis
of the logging data and counteraction in a local edge computing of the log data and counteraction in a local ECD or a distributed
device or a distributed database like a blockchain. The centralized database like a blockchain. The centralized approach stores log data
approach stores logging data collected from VANET into a remote collected from VANET into a remote logging server in a Vehicular
logging server in a vehicular cloud as a central cloud, so it takes Cloud as a central cloud, so it takes time to deliver the log data to
time to deliver the logging data to a remote logging server. On the a remote logging server. On the other hand, the decentralized
other hand, the decentralized approach stores the logging data into a approach stores the log data into a nearby edge computing device as a
nearby edge computing device as a local logging server or a nearby local logging server or a nearby blockchain node, which participates
blockchain node, which participates in a blockchain network. On the in a blockchain network. On the stored log data, an analyzer needs
stored logging data, an analyzer needs to perform a machine learning to perform a machine learning technique (e.g., deep learning) and
technique (e.g., Deep Learning) and seek suspicious behaviors of the seek suspicious behaviors of the vehicles. If such an analyzer is
vehicles. If such an analyzer is located either within or near the located either within or near the edge computing device, it can
edge computing device, it can access the logging data with a short access the log data with a short delay, analyze it quickly, and
delay, analyze it quickly, and generate feedback to allow for a quick generate feedback to allow for a quick counteraction against such
counteraction against such malicious behaviors. On the other hand, malicious behaviors. On the other hand, if the Vehicular Cloud with
if the vehicular cloud with the logging data is far away from a the log data is far away from a problematic VANET with malicious
problematic VANET with malicious behaviors, the centralized approach behaviors, the centralized approach takes a longer time with the
takes a long time with the analysis with the logging data and the analysis of the log data and the decision-making on malicious
decision-making on malicious behaviors than the decentralized behaviors than the decentralized approach. If the log data is
approach. If the logging data is encrypted by a secret key, it can encrypted by a secret key, it can be protected from the observation
be protected from the observation of a hacker. The secret key of a hacker. The secret key sharing among legal vehicles, ECDs, and
sharing among legal vehicles, edge computing devices, and vehicular Vehicular Clouds should be supported efficiently.
clouds should be supported efficiently.
Logging information can release privacy breakage of a vehicle. The Log data can release privacy breakage of a vehicle. The log data can
logging information can contain the MAC address and IPv6 address for contain the MAC address and IPv6 address for a vehicle's wireless
a vehicle's wireless network interface. If the unique MAC address of network interface. If the unique MAC address of the wireless network
the wireless network interface is used, a hacker can track the interface is used, a hacker can track the vehicle with that MAC
vehicle with that MAC address, so can track the privacy information address and can track the privacy information of the vehicle's driver
of the vehicle's driver (e.g., location information). To prevent (e.g., location information). To prevent this privacy breakage, a
this privacy breakage, a MAC address pseudonym can be used for the MAC address pseudonym can be used for the MAC address of the wireless
MAC address of the wireless network interface, and the corresponding network interface, and the corresponding IPv6 address should be based
IPv6 address should be based on such a MAC address pseudonym. By on such a MAC address pseudonym. By solving a privacy issue of a
solving a privacy issue of a vehicle's identity in logging, vehicles vehicle's identity in logging, vehicles may observe each other's
may observe activities of each other to identify any misbehavior activities to identify any misbehaviors without privacy breakage.
without privacy breakage. Once identifying a misbehavior, a vehicle Once identifying a misbehavior, a vehicle shall have a way to either
shall have a way to either isolate itself from others or isolate a isolate itself from others or isolate a suspicious vehicle by
suspicious vehicle by informing other vehicles. informing other vehicles.
For completely secure vehicular networks, we shall embrace the For completely secure vehicular networks, we shall embrace the
concept of "zero-trust" for vehicles in which no vehicle is trustable concept of "zero-trust" for vehicles where no vehicle is trustable
and verifying every message (such as IPv6 control messages including and verifying every message (such as IPv6 control messages including
ND, DAD, NUD, and application layer messages) is necessary. In this ND, DAD, NUD, and application-layer messages) is necessary. In this
way, vehicular networks can defense many possible cyberattacks. way, vehicular networks can defend against many possible
Thus, we need to have an efficient zero-trust framework or mechanism cyberattacks. Thus, we need to have an efficient zero-trust
for the vehicular networks. framework or mechanism for vehicular networks.
For the non-repudiation of the harmful activities from malicious For the non-repudiation of the harmful activities from malicious
vehicles, which it is difficult for other normal vehicles to identify vehicles, as it is difficult for other normal vehicles to identify
them, an additional and advanced approach is needed. One possible them, an additional and advanced approach is needed. One possible
approach is to use a blockchain-based approach [Bitcoin] as an IPv6 approach is to use a blockchain-based approach [Bitcoin] as an IPv6
security checking framework. Each IPv6 packet from a vehicle can be security checking framework. Each IPv6 packet from a vehicle can be
treated as a transaction and the neighboring vehicles can play the treated as a transaction, and the neighboring vehicles can play the
role of peers in a consensus method of a blockchain [Bitcoin] role of peers in a consensus method of a blockchain [Bitcoin]
[Vehicular-BlockChain]. For a blockchain's efficient consensus in [Vehicular-BlockChain]. For a blockchain's efficient consensus in
vehicular networks having fast moving vehicles, a new consensus vehicular networks having fast-moving vehicles, either a new
algorithm needs to be developed, or an existing consensus algorithm consensus algorithm needs to be developed, or an existing consensus
needs to be enhanced. In addition, a consensus-based mechanism for algorithm needs to be enhanced. In addition, a consensus-based
the security of vehicular networks in the IPv6 layer can also be mechanism for the security of vehicular networks in the IPv6 layer
considered. A group of servers as blockchain infrastructure can be can also be considered. A group of servers as blockchain
part of the security checking process in the IP layer. infrastructure can be part of the security checking process in the IP
layer.
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, especially for a long-living transport-layer session or IPv6 address, especially for a long-living transport-layer session
(e.g., voice call over IP and video streaming service), a MAC address (e.g., voice call over IP and video streaming service), a MAC address
pseudonym needs to be provided to each vehicle; that is, each vehicle pseudonym needs to be provided to each vehicle; that is, each vehicle
periodically updates its MAC address and its IPv6 address needs to be periodically updates its MAC address, and the vehicle's IPv6 address
updated accordingly by the MAC address change [RFC4086][RFC8981]. needs to be updated accordingly by the MAC address change [RFC4086]
Such an update of the MAC and IPv6 addresses should not interrupt the [RFC8981]. Such an update of the MAC and IPv6 addresses should not
E2E communications between two vehicles (or between a vehicle and an interrupt the E2E communications between two vehicles (or between a
IP-RSU) for a long-living transport-layer session. However, if this vehicle and an IP-RSU) for a long-living transport-layer session.
pseudonym is performed without strong E2E confidentiality (using However, if this pseudonym is performed without strong E2E
either IPsec or TLS), there will be no privacy benefit from changing confidentiality (using either IPsec or TLS), there will be no privacy
MAC and IPv6 addresses, because an adversary can observe the change benefit from changing MAC and IPv6 addresses because an adversary can
of the MAC and IPv6 addresses and track the vehicle with those observe the change of the MAC and IPv6 addresses and track the
addresses. Thus, the MAC address pseudonym and the IPv6 address vehicle with those addresses. Thus, the MAC address pseudonym and
update should be performed with strong E2E confidentiality. the IPv6 address update should be performed with strong E2E
confidentiality.
The privacy exposure to the TCC and via V2I is mostly about the The privacy exposure to the TCC via V2I is mostly about the location
location information of vehicles, and may also include other in- information of vehicles and may also include other in-vehicle
vehicle activities such as transactions of credit cards. The activities, such as transactions of credit cards. The assumed,
assumed, trusted actors are the owner of a vehicle, an authorized trusted actors are the owner of a vehicle, an authorized vehicle
vehicle service provider (e.g., navigation service provider), and an service provider (e.g., navigation service provider), and an
authorized vehicle manufacturer for providing after-sales services. authorized vehicle manufacturer for providing after-sales services.
In addition, privacy concerns for excessively collecting vehicle In addition, privacy concerns for excessively collecting vehicle
activities from roadway operators such as public transportation activities from roadway operators, such as public transportation
administrators and private contractors may also pose threats on administrators and private contractors, may also pose threats on
violating privacy rights of vehicles. It might be interesting to violating privacy rights of vehicles. It might be interesting to
find a solution from a technology point of view along with public find a solution from a technological point of view along with public
policy development for the issue. policy development for the issue.
The "multicasting" of the location information of a VRU's smartphone The "multicasting" of the location information of a VRU's smartphone
means IPv6 multicasting. There is a possible security attack related means IPv6 multicasting. There is a possible security attack related
to this multicasting. Attackers can use "fake identifiers" as source to this multicasting. Attackers can use "fake identifiers" as source
IPv6 addresses of their devices to generate IPv6 packets and IPv6 addresses of their devices to generate IPv6 packets and
multicast them to nearby vehicles in order to make a confusion that multicast them to nearby vehicles in order to cause confusion that
those vehicles are surrounded by other vehicles or pedestrians. As a those vehicles are surrounded by other vehicles or pedestrians. As a
result, navigation services (e.g., Google Maps [Google-Maps] and Waze result, navigation services (e.g., Google Maps [Google-Maps] and Waze
[Waze]) can be confused with fake road traffic by those vehicles or [Waze]) can be confused with fake road traffic by those vehicles or
smartphones with "fake identifiers" [Fake-Identifier-Attack]. This smartphones with "fake identifiers" [Fake-Identifier-Attack]. This
attack with "fake identifiers" should be detected and handled by attack with "fake identifiers" should be detected and handled by
vehicular networks. To cope with this attack, both legal vehicles vehicular networks. To cope with this attack, both legal vehicles
and legal VRUs' smartphones can be registered with a traffic control and legal VRUs' smartphones can be registered with a TCC and their
center (called TCC) and their locations can be tracked by the TCC. locations can be tracked by the TCC. With this tracking, the TCC can
With this tracking, the TCC can tell the road traffic conditions tell the road traffic conditions caused by those vehicles and
caused by those vehicles and smartphones. In addition, to prevent smartphones. In addition, to prevent hackers from tracking the
hackers from tracking the locations of those vehicles and locations of those vehicles and smartphones, either a MAC address
smartphones, either a MAC address pseudonym pseudonym [MAC-ADD-RAN] or secure IPv6 address generation [RFC7721]
[I-D.ietf-madinas-mac-address-randomization] or secure IPv6 address can be used to protect the privacy of those vehicles and smartphones.
generation [RFC7721] can be used to protect the privacy of those
vehicles and smartphones.
7. IANA Considerations 7. IANA Considerations
This document does not require any IANA actions. This document has no IANA actions.
8. References 8. References
8.1. Normative References 8.1. Normative References
[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,
DOI 10.17487/RFC4861, September 2007, DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>. <https://www.rfc-editor.org/info/rfc4861>.
skipping to change at page 38, line 13 skipping to change at line 1749
2011, <https://www.rfc-editor.org/info/rfc6275>. 2011, <https://www.rfc-editor.org/info/rfc6275>.
[RFC8691] Benamar, N., Härri, J., Lee, J., and T. Ernst, "Basic [RFC8691] Benamar, N., Härri, J., Lee, J., and T. Ernst, "Basic
Support for IPv6 Networks Operating Outside the Context of Support for IPv6 Networks Operating Outside the Context of
a Basic Service Set over IEEE Std 802.11", RFC 8691, a Basic Service Set over IEEE Std 802.11", RFC 8691,
DOI 10.17487/RFC8691, December 2019, DOI 10.17487/RFC8691, December 2019,
<https://www.rfc-editor.org/info/rfc8691>. <https://www.rfc-editor.org/info/rfc8691>.
8.2. Informative References 8.2. Informative References
[AERO] Templin, F. L., Ed., "Automatic Extended Route
Optimization (AERO)", Work in Progress, Internet-Draft,
draft-templin-intarea-aero-11, 10 January 2023,
<https://datatracker.ietf.org/doc/html/draft-templin-
intarea-aero-11>.
[Automotive-Sensing]
Choi, J., Va, V., Gonzalez-Prelcic, N., Daniels, R., Bhat,
C., and R. Heath, "Millimeter-Wave Vehicular Communication
to Support Massive Automotive Sensing", IEEE
Communications Magazine, Volume 54, Issue 12, pp. 160-167,
DOI 10.1109/MCOM.2016.1600071CM, December 2016,
<https://doi.org/10.1109/MCOM.2016.1600071CM>.
[Bitcoin] Nakamoto, S., "Bitcoin: A Peer-to-Peer Electronic Cash
System", <https://bitcoin.org/bitcoin.pdf>.
[CA-Cruise-Control]
California Partners for Advanced Transportation Technology
(PATH), "Cooperative Adaptive Cruise Control",
<https://path.berkeley.edu/research/connected-and-
automated-vehicles/cooperative-adaptive-cruise-control>.
[CASD] Shen, Y., Jeong, J., Oh, T., and S. H. Son, "CASD: A
Framework of Context-Awareness Safety Driving in Vehicular
Networks", 30th International Conference on Advanced
Information Networking and Applications Workshops (WAINA),
DOI 10.1109/WAINA.2016.74, March 2016,
<https://doi.org/10.1109/WAINA.2016.74>.
[CBDN] Kim, J., Kim, S., Jeong, J., Kim, H., Park, J., and T.
Kim, "CBDN: Cloud-Based Drone Navigation for Efficient
Battery Charging in Drone Networks", IEEE Transactions on
Intelligent Transportation Systems, Volume 20, Issue 11,
pp. 4174-4191, DOI 10.1109/TITS.2018.2883058, November
2019, <https://doi.org/10.1109/TITS.2018.2883058>.
[CNP] Mugabarigira, B., Shen, Y., Jeong, J., Oh, T., and H.
Jeong, "Context-Aware Navigation Protocol for Safe Driving
in Vehicular Cyber-Physical Systems", IEEE Transactions on
Intelligent Transportation Systems, Volume 24, Issue 1,
pp. 128-138, DOI 10.1109/TITS.2022.3210753, January 2023,
<https://doi.org/10.1109/TITS.2022.3210753>.
[DFC] Jeong, J., Shen, Y., Kim, S., Choe, D., Lee, K., and Y.
Kim, "DFC: Device-free human counting through WiFi fine-
grained subcarrier information", IET Communications,
Volume 15, Issue 3, pp. 337-350, DOI 10.1049/cmu2.12043,
February 2021, <https://doi.org/10.1049/cmu2.12043>.
[DSRC] ASTM International, "Standard Specification for
Telecommunications and Information Exchange Between
Roadside and Vehicle Systems - 5 GHz Band Dedicated Short
Range Communications (DSRC) Medium Access Control (MAC)
and Physical Layer (PHY) Specifications",
ASTM E2213-03(2010), DOI 10.1520/E2213-03R10, September
2018, <https://doi.org/10.1520/E2213-03R10>.
[EU-2008-671-EC]
European Union, "COMMISSION DECISION of 5 August 2008 on
the harmonised use of radio spectrum in the 5 875-5 905
MHz frequency band for safety-related applications of
Intelligent Transport Systems (ITS)", EU 2008/671/EC,
August 2008, <https://eur-lex.europa.eu/legal-
content/EN/TXT/PDF/?uri=CELEX:32008D0671&rid=7>.
[Fake-Identifier-Attack]
ABC News, "Berlin artist uses handcart full of smartphones
to trick Google Maps' traffic algorithm into thinking
there is traffic jam", February 2020,
<https://www.abc.net.au/news/2020-02-04/man-creates-fake-
traffic-jam-on-google-maps-by-carting-99-phones/11929136>.
[FCC-ITS-Modification]
Federal Communications Commission, "FCC Modernizes 5.9 GHz
Band to Improve Wi-Fi and Automotive Safety", November
2020, <https://www.fcc.gov/document/fcc-modernizes-59-ghz-
band-improve-wi-fi-and-automotive-safety-0>.
[FirstNet] FirstNet Authority, "First Responder Network Authority |
FirstNet", <https://www.firstnet.gov/>.
[FirstNet-Report]
FirstNet, "FY 2017: ANNUAL REPORT TO CONGRESS, Advancing
Public Safety Broadband Communications", FirstNet FY 2017,
December 2017, <https://www.firstnet.gov/system/tdf/
FirstNet-Annual-Report-
FY2017.pdf?file=1&type=node&id=449>.
[FPC-DMM] Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
Moses, D., and C. E. Perkins, "Protocol for Forwarding
Policy Configuration (FPC) in DMM", Work in Progress,
Internet-Draft, draft-ietf-dmm-fpc-cpdp-14, 22 September
2020, <https://datatracker.ietf.org/doc/html/draft-ietf-
dmm-fpc-cpdp-14>.
[Fuel-Efficient]
van de Hoef, S., Johansson, K., and D. Dimarogonas, "Fuel-
Efficient En Route Formation of Truck Platoons", IEEE
Transactions on Intelligent Transportation Systems, Volume
19, Issue 1, pp. 102-112, DOI 10.1109/TITS.2017.2700021,
January 2018, <https://doi.org/10.1109/TITS.2017.2700021>.
[Google-Maps]
Google, "Google Maps", <https://www.google.com/maps/>.
[Identity-Management]
Wetterwald, M., Hrizi, F., and P. Cataldi, "Cross-layer
identities management in ITS stations", 10th IEEE
International Conference on ITS Telecommunications,
November 2010,
<https://www.eurecom.fr/fr/publication/3205>.
[IEEE-802.11-OCB]
IEEE, "IEEE Standard for Information technology -
Telecommunications and information exchange between
systems Local and metropolitan area networks-Specific
requirements - Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications",
DOI 10.1109/IEEESTD.2016.7786995, IEEE Std 802.11-2016,
December 2016,
<https://doi.org/10.1109/IEEESTD.2016.7786995>.
[IEEE-802.11p]
IEEE, "IEEE Standard for Information technology-- Local
and metropolitan area networks-- Specific requirements--
Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications Amendment 6: Wireless
Access in Vehicular Environments",
DOI 10.1109/IEEESTD.2010.5514475, IEEE Std 802.11p-2010,
July 2010, <https://doi.org/10.1109/IEEESTD.2010.5514475>.
[In-Car-Network]
Lim, H., Volker, L., and D. Herrscher, "Challenges in a
future IP/Ethernet-based in-car network for real-time
applications", Proceedings of the 48th Design Automation
Conference, pp. 7-12, DOI 10.1145/2024724.2024727, June
2011, <https://doi.org/10.1145/2024724.2024727>.
[IPPL] Nordmark, E., "IP over Intentionally Partially Partitioned
Links", Work in Progress, Internet-Draft, draft-ietf-
intarea-ippl-00, 30 March 2017,
<https://datatracker.ietf.org/doc/html/draft-ietf-intarea-
ippl-00>.
[ISO-ITS-IPv6]
ISO/TC 204, "Intelligent transport systems -
Communications access for land mobiles (CALM) - IPv6
Networking", ISO 21210:2012, June 2012,
<https://www.iso.org/standard/46549.html>.
[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, <https://www.iso.org/standard/65691.html>.
[LIFS] Wang, J., Xiong, J., Jiang, H., Jamieson, K., Chen, X.,
Fang, D., and C. Wang, "Low Human-Effort, Device-Free
Localization with Fine-Grained Subcarrier Information",
IEEE Transactions on Mobile Computing, Volume 17, Issue
11, pp. 2550-2563, DOI 10.1109/TMC.2018.2812746, November
2018, <https://doi.org/10.1109/TMC.2018.2812746>.
[MAC-ADD-RAN]
Zúñiga, JC., Bernardos, CJ., Ed., and A. Andersdotter,
"MAC address randomization", Work in Progress, Internet-
Draft, draft-ietf-madinas-mac-address-randomization-04, 22
October 2022, <https://datatracker.ietf.org/doc/html/
draft-ietf-madinas-mac-address-randomization-04>.
[NHTSA-ACAS-Report]
National Highway Traffic Safety Administration (NHTSA),
"Automotive Collision Avoidance Systems (ACAS) Program
Final Report", DOT HS 809 080, August 2000,
<https://one.nhtsa.gov/people/injury/research/pub/ACAS/
ACAS_index.htm>.
[OMNI] Templin, F. L., Ed., "Transmission of IP Packets over
Overlay Multilink Network (OMNI) Interfaces", Work in
Progress, Internet-Draft, draft-templin-intarea-omni-25,
15 February 2023, <https://datatracker.ietf.org/doc/html/
draft-templin-intarea-omni-25>.
[PARCELS] Templin, F. L., Ed., "IP Parcels", Work in Progress,
Internet-Draft, draft-templin-intarea-parcels-51, 15
February 2023, <https://datatracker.ietf.org/doc/html/
draft-templin-intarea-parcels-51>.
[PSCE] European Commission, "PSCEurope Public Safety
Communications Europe", <https://www.psc-europe.eu/>.
[RCM-USE-CASES]
Henry, J. and Y. Lee, "Randomized and Changing MAC Address
Use Cases", Work in Progress, Internet-Draft, draft-ietf-
madinas-use-cases-03, 6 October 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-madinas-
use-cases-03>.
[RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast [RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast
Listener Discovery (MLD) for IPv6", RFC 2710, Listener Discovery (MLD) for IPv6", RFC 2710,
DOI 10.17487/RFC2710, October 1999, DOI 10.17487/RFC2710, October 1999,
<https://www.rfc-editor.org/info/rfc2710>. <https://www.rfc-editor.org/info/rfc2710>.
[RFC3626] Clausen, T., Ed. and P. Jacquet, Ed., "Optimized Link [RFC3626] Clausen, T., Ed. and P. Jacquet, Ed., "Optimized Link
State Routing Protocol (OLSR)", RFC 3626, State Routing Protocol (OLSR)", RFC 3626,
DOI 10.17487/RFC3626, October 2003, DOI 10.17487/RFC3626, October 2003,
<https://www.rfc-editor.org/info/rfc3626>. <https://www.rfc-editor.org/info/rfc3626>.
skipping to change at page 39, line 25 skipping to change at line 2006
<https://www.rfc-editor.org/info/rfc4303>. <https://www.rfc-editor.org/info/rfc4303>.
[RFC4308] Hoffman, P., "Cryptographic Suites for IPsec", RFC 4308, [RFC4308] Hoffman, P., "Cryptographic Suites for IPsec", RFC 4308,
DOI 10.17487/RFC4308, December 2005, DOI 10.17487/RFC4308, December 2005,
<https://www.rfc-editor.org/info/rfc4308>. <https://www.rfc-editor.org/info/rfc4308>.
[RFC4821] Mathis, M. and J. Heffner, "Packetization Layer Path MTU [RFC4821] Mathis, M. and J. Heffner, "Packetization Layer Path MTU
Discovery", RFC 4821, DOI 10.17487/RFC4821, March 2007, Discovery", RFC 4821, DOI 10.17487/RFC4821, March 2007,
<https://www.rfc-editor.org/info/rfc4821>. <https://www.rfc-editor.org/info/rfc4821>.
[RFC4885] Ernst, T. and Y. H-Lach, "Network Mobility Support [RFC4885] Ernst, T. and H-Y. Lach, "Network Mobility Support
Terminology", RFC 4885, DOI 10.17487/RFC4885, July 2007, Terminology", RFC 4885, DOI 10.17487/RFC4885, July 2007,
<https://www.rfc-editor.org/info/rfc4885>. <https://www.rfc-editor.org/info/rfc4885>.
[RFC4888] Ng, C., Thubert, P., Watari, M., and F. Zhao, "Network [RFC4888] Ng, C., Thubert, P., Watari, M., and F. Zhao, "Network
Mobility Route Optimization Problem Statement", RFC 4888, Mobility Route Optimization Problem Statement", RFC 4888,
DOI 10.17487/RFC4888, July 2007, DOI 10.17487/RFC4888, July 2007,
<https://www.rfc-editor.org/info/rfc4888>. <https://www.rfc-editor.org/info/rfc4888>.
[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",
skipping to change at page 41, line 25 skipping to change at line 2098
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T. [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2 Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <https://www.rfc-editor.org/info/rfc7296>. 2014, <https://www.rfc-editor.org/info/rfc7296>.
[RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J. [RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J.
Korhonen, "Requirements for Distributed Mobility Korhonen, "Requirements for Distributed Mobility
Management", RFC 7333, DOI 10.17487/RFC7333, August 2014, Management", RFC 7333, DOI 10.17487/RFC7333, August 2014,
<https://www.rfc-editor.org/info/rfc7333>. <https://www.rfc-editor.org/info/rfc7333>.
[RFC7427] Kivinen, T. and J. Snyder, "Signature Authentication in
the Internet Key Exchange Version 2 (IKEv2)", RFC 7427,
DOI 10.17487/RFC7427, January 2015,
<https://www.rfc-editor.org/info/rfc7427>.
[RFC7429] Liu, D., Ed., Zuniga, JC., Ed., Seite, P., Chan, H., and [RFC7429] Liu, D., Ed., Zuniga, JC., Ed., Seite, P., Chan, H., and
CJ. Bernardos, "Distributed Mobility Management: Current CJ. Bernardos, "Distributed Mobility Management: Current
Practices and Gap Analysis", RFC 7429, Practices and Gap Analysis", RFC 7429,
DOI 10.17487/RFC7429, January 2015, DOI 10.17487/RFC7429, January 2015,
<https://www.rfc-editor.org/info/rfc7429>. <https://www.rfc-editor.org/info/rfc7429>.
[RFC7427] Kivinen, T. and J. Snyder, "Signature Authentication in
the Internet Key Exchange Version 2 (IKEv2)", RFC 7427,
DOI 10.17487/RFC7427, January 2015,
<https://www.rfc-editor.org/info/rfc7427>.
[RFC7466] Dearlove, C. and T. Clausen, "An Optimization for the [RFC7466] Dearlove, C. and T. Clausen, "An Optimization for the
Mobile Ad Hoc Network (MANET) Neighborhood Discovery Mobile Ad Hoc Network (MANET) Neighborhood Discovery
Protocol (NHDP)", RFC 7466, DOI 10.17487/RFC7466, March Protocol (NHDP)", RFC 7466, DOI 10.17487/RFC7466, March
2015, <https://www.rfc-editor.org/info/rfc7466>. 2015, <https://www.rfc-editor.org/info/rfc7466>.
[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy
Considerations for IPv6 Address Generation Mechanisms", Considerations for IPv6 Address Generation Mechanisms",
RFC 7721, DOI 10.17487/RFC7721, March 2016, RFC 7721, DOI 10.17487/RFC7721, March 2016,
<https://www.rfc-editor.org/info/rfc7721>. <https://www.rfc-editor.org/info/rfc7721>.
skipping to change at page 43, line 21 skipping to change at line 2184
"Temporary Address Extensions for Stateless Address "Temporary Address Extensions for Stateless Address
Autoconfiguration in IPv6", RFC 8981, Autoconfiguration in IPv6", RFC 8981,
DOI 10.17487/RFC8981, February 2021, DOI 10.17487/RFC8981, February 2021,
<https://www.rfc-editor.org/info/rfc8981>. <https://www.rfc-editor.org/info/rfc8981>.
[RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", RFC 9000, Multiplexed and Secure Transport", RFC 9000,
DOI 10.17487/RFC9000, May 2021, DOI 10.17487/RFC9000, May 2021,
<https://www.rfc-editor.org/info/rfc9000>. <https://www.rfc-editor.org/info/rfc9000>.
[RFC9099] Vyncke, É., Chittimaneni, K., Kaeo, M., and E. Rey,
"Operational Security Considerations for IPv6 Networks",
RFC 9099, DOI 10.17487/RFC9099, August 2021,
<https://www.rfc-editor.org/info/rfc9099>.
[RFC9119] Perkins, C., McBride, M., Stanley, D., Kumari, W., and JC. [RFC9119] Perkins, C., McBride, M., Stanley, D., Kumari, W., and JC.
Zúñiga, "Multicast Considerations over IEEE 802 Wireless Zúñiga, "Multicast Considerations over IEEE 802 Wireless
Media", RFC 9119, DOI 10.17487/RFC9119, October 2021, Media", RFC 9119, DOI 10.17487/RFC9119, October 2021,
<https://www.rfc-editor.org/info/rfc9119>. <https://www.rfc-editor.org/info/rfc9119>.
[I-D.ietf-intarea-ippl] [RFC9300] Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Nordmark, E., "IP over Intentionally Partially Partitioned Cabellos, Ed., "The Locator/ID Separation Protocol
Links", Work in Progress, Internet-Draft, draft-ietf- (LISP)", RFC 9300, DOI 10.17487/RFC9300, October 2022,
intarea-ippl-00, 30 March 2017, <https://www.rfc-editor.org/info/rfc9300>.
<https://www.ietf.org/archive/id/draft-ietf-intarea-ippl-
00.txt>.
[I-D.ietf-lisp-rfc6830bis]
Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Cabellos, "The Locator/ID Separation Protocol (LISP)",
Work in Progress, Internet-Draft, draft-ietf-lisp-
rfc6830bis-38, 7 May 2022,
<https://www.ietf.org/archive/id/draft-ietf-lisp-
rfc6830bis-38.txt>.
[I-D.templin-6man-aero]
Templin, F., "Automatic Extended Route Optimization
(AERO)", Work in Progress, Internet-Draft, draft-templin-
6man-aero-63, 12 October 2022,
<https://www.ietf.org/archive/id/draft-templin-6man-aero-
63.txt>.
[I-D.templin-6man-omni]
Templin, F., "Transmission of IP Packets over Overlay
Multilink Network (OMNI) Interfaces", Work in Progress,
Internet-Draft, draft-templin-6man-omni-74, 12 October
2022, <https://www.ietf.org/archive/id/draft-templin-6man-
omni-74.txt>.
[I-D.templin-ipwave-uam-its]
Fred Templin, L., "Urban Air Mobility Implications for
Intelligent Transportation Systems", Work in Progress,
Internet-Draft, draft-templin-ipwave-uam-its-04, 4 January
2021, <https://www.ietf.org/archive/id/draft-templin-
ipwave-uam-its-04.txt>.
[I-D.templin-intarea-parcels]
Templin, F., "IP Parcels", Work in Progress, Internet-
Draft, draft-templin-intarea-parcels-16, 6 October 2022,
<https://www.ietf.org/archive/id/draft-templin-intarea-
parcels-16.txt>.
[I-D.ietf-dmm-fpc-cpdp]
Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
Moses, D., and E. Charles Perkins, "Protocol for
Forwarding Policy Configuration (FPC) in DMM", Work in
Progress, Internet-Draft, draft-ietf-dmm-fpc-cpdp-14, 22
September 2020, <https://www.ietf.org/archive/id/draft-
ietf-dmm-fpc-cpdp-14.txt>.
[I-D.thubert-6man-ipv6-over-wireless]
Thubert, P., "IPv6 Neighbor Discovery on Wireless
Networks", Work in Progress, Internet-Draft, draft-
thubert-6man-ipv6-over-wireless-12, 11 October 2022,
<https://www.ietf.org/archive/id/draft-thubert-6man-ipv6-
over-wireless-12.txt>.
[I-D.ietf-madinas-mac-address-randomization]
Zúñiga, J. C., Bernardos, C. J., and A. Andersdotter, "MAC
address randomization", Work in Progress, Internet-Draft,
draft-ietf-madinas-mac-address-randomization-04, 22
October 2022, <https://www.ietf.org/archive/id/draft-ietf-
madinas-mac-address-randomization-04.txt>.
[I-D.ietf-madinas-use-cases]
Henry, J. and Y. Lee, "Randomized and Changing MAC Address
Use Cases", Work in Progress, Internet-Draft, draft-ietf-
madinas-use-cases-03, 6 October 2022,
<https://www.ietf.org/archive/id/draft-ietf-madinas-use-
cases-03.txt>.
[I-D.jeong-ipwave-vehicular-neighbor-discovery]
Jeong, J. P., Shen, Y. C., Kwon, J., and S. Cespedes,
"Vehicular Neighbor Discovery for IP-Based Vehicular
Networks", Work in Progress, Internet-Draft, draft-jeong-
ipwave-vehicular-neighbor-discovery-14, 25 July 2022,
<https://www.ietf.org/archive/id/draft-jeong-ipwave-
vehicular-neighbor-discovery-14.txt>.
[I-D.jeong-ipwave-vehicular-mobility-management]
Jeong, J. P., Mugabarigira, B. A., Shen, Y. C., and H.
Jung, "Vehicular Mobility Management for IP-Based
Vehicular Networks", Work in Progress, Internet-Draft,
draft-jeong-ipwave-vehicular-mobility-management-08, 25
July 2022, <https://www.ietf.org/archive/id/draft-jeong-
ipwave-vehicular-mobility-management-08.txt>.
[I-D.jeong-ipwave-security-privacy]
Jeong, J. P., Shen, Y. C., Jung, H., Park, J., and T. T.
Oh, "Basic Support for Security and Privacy in IP-Based
Vehicular Networks", Work in Progress, Internet-Draft,
draft-jeong-ipwave-security-privacy-06, 25 July 2022,
<https://www.ietf.org/archive/id/draft-jeong-ipwave-
security-privacy-06.txt>.
[DSRC] ASTM International, "Standard Specification for
Telecommunications and Information Exchange Between
Roadside and Vehicle Systems - 5 GHz Band Dedicated Short
Range Communications (DSRC) Medium Access Control (MAC)
and Physical Layer (PHY) Specifications",
ASTM E2213-03(2010), October 2010.
[EU-2008-671-EC]
European Union, "Commission Decision of 5 August 2008 on
the Harmonised Use of Radio Spectrum in the 5875 - 5905
MHz Frequency Band for Safety-related Applications of
Intelligent Transport Systems (ITS)", EU 2008/671/EC,
August 2008.
[IEEE-802.11p]
"Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications - Amendment 6:
Wireless Access in Vehicular Environments", IEEE Std
802.11p-2010, June 2010.
[IEEE-802.11-OCB]
"Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications", IEEE Std
802.11-2016, December 2016.
[WAVE-1609.0]
IEEE 1609 Working Group, "IEEE Guide for Wireless Access
in Vehicular Environments (WAVE) - Architecture", IEEE Std
1609.0-2013, March 2014.
[WAVE-1609.2]
IEEE 1609 Working Group, "IEEE Standard for Wireless
Access in Vehicular Environments - Security Services for
Applications and Management Messages", IEEE Std
1609.2-2016, March 2016.
[WAVE-1609.3]
IEEE 1609 Working Group, "IEEE Standard for Wireless
Access in Vehicular Environments (WAVE) - Networking
Services", IEEE Std 1609.3-2016, April 2016.
[WAVE-1609.4]
IEEE 1609 Working Group, "IEEE Standard for Wireless
Access in Vehicular Environments (WAVE) - Multi-Channel
Operation", IEEE Std 1609.4-2016, March 2016.
[ISO-ITS-IPv6]
ISO/TC 204, "Intelligent Transport Systems -
Communications Access for Land Mobiles (CALM) - IPv6
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.
[TS-23.285-3GPP]
3GPP, "Architecture Enhancements for V2X Services", 3GPP
TS 23.285/Version 16.2.0, December 2019.
[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.
[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.
[VIP-WAVE] Cespedes, S., Lu, N., and X. Shen, "VIP-WAVE: On the
Feasibility of IP Communications in 802.11p Vehicular
Networks", IEEE Transactions on Intelligent Transportation
Systems, vol. 14, no. 1, March 2013.
[Identity-Management]
Wetterwald, M., Hrizi, F., and P. Cataldi, "Cross-layer
Identities Management in ITS Stations", The 10th
International Conference on ITS Telecommunications,
November 2010.
[SAINT] Jeong, J., Jeong, H., Lee, E., Oh, T., and D. Du, "SAINT: [SAINT] Jeong, J., Jeong, H., Lee, E., Oh, T., and D. H. C. Du,
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Vehicular Technology, Vol. 65, No. 6, June 2016. Transactions on Vehicular Technology, Volume 65, Issue 6,
pp. 4053-4067, DOI 10.1109/TVT.2015.2476958, June 2016,
<https://doi.org/10.1109/TVT.2015.2476958>.
[SAINTplus] [SAINTplus]
Shen, Y., Lee, J., Jeong, H., Jeong, J., Lee, E., and D. Shen, Y., Lee, J., Jeong, H., Jeong, J., Lee, E., and D.
Du, "SAINT+: Self-Adaptive Interactive Navigation Tool+ H. C. Du, "SAINT+: Self-Adaptive Interactive Navigation
for Emergency Service Delivery Optimization", Tool+ for Emergency Service Delivery Optimization", IEEE
IEEE Transactions on Intelligent Transportation Systems, Transactions on Intelligent Transportation Systems, Volume
June 2017. 19, Issue 4, pp. 1038-1053, DOI 10.1109/TITS.2017.2710881,
June 2017, <https://doi.org/10.1109/TITS.2017.2710881>.
[SANA] Hwang, T. and J. Jeong, "SANA: Safety-Aware Navigation [SANA] Hwang, T. and J. Jeong, "SANA: Safety-Aware Navigation
Application for Pedestrian Protection in Vehicular Application for Pedestrian Protection in Vehicular
Networks", Springer Lecture Notes in Computer Science Networks", Lecture Notes in Computer Science book series
(LNCS), Vol. 9502, December 2015. (LNISA, Volume 9502), DOI 10.1007/978-3-319-27293-1_12,
December 2015,
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[CA-Cruise-Control]
California Partners for Advanced Transportation Technology
(PATH), "Cooperative Adaptive Cruise Control", Available:
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automated-vehicles/cooperative-adaptive-cruise-control,
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[Truck-Platooning]
California Partners for Advanced Transportation Technology
(PATH), "Automated Truck Platooning", Available:
https://path.berkeley.edu/research/connected-and-
automated-vehicles/truck-platooning, 2022.
[FirstNet] U.S. National Telecommunications and Information
Administration (NTIA), "First Responder Network Authority
(FirstNet)", Available: https://www.firstnet.gov/, 2022.
[PSCE] European Commission, "Public Safety Communications Europe [Scrambler-Attack]
(PSCE)", Available: https://www.psc-europe.eu/, 2022. Bloessl, B., Sommer, C., Dressier, F., and D. Eckhoff,
"The scrambler attack: A robust physical layer attack on
location privacy in vehicular networks", 2015
International Conference on Computing, Networking and
Communications (ICNC), DOI 10.1109/ICCNC.2015.7069376,
February 2015,
<https://doi.org/10.1109/ICCNC.2015.7069376>.
[FirstNet-Report] [SEC-PRIV] Jeong, J., Ed., Shen, Y., Jung, H., Park, J., and T. Oh,
First Responder Network Authority, "FY 2017: ANNUAL REPORT "Basic Support for Security and Privacy in IP-Based
TO CONGRESS, Advancing Public Safety Broadband Vehicular Networks", Work in Progress, Internet-Draft,
Communications", FirstNet FY 2017, December 2017. draft-jeong-ipwave-security-privacy-06, 25 July 2022,
<https://datatracker.ietf.org/doc/html/draft-jeong-ipwave-
security-privacy-06>.
[SignalGuru] [SignalGuru]
Koukoumidis, E., Peh, L., and M. Martonosi, "SignalGuru: Koukoumidis, E., Peh, L., and M. Martonosi, "SignalGuru:
Leveraging Mobile Phones for Collaborative Traffic Signal leveraging mobile phones for collaborative traffic signal
Schedule Advisory", ACM MobiSys, June 2011. schedule advisory", MobiSys '11: Proceedings of the 9th
international conference on Mobile systems, applications,
and services, pp. 127-140, DOI 10.1145/1999995.2000008,
June 2011, <https://doi.org/10.1145/1999995.2000008>.
[Fuel-Efficient] [TR-22.886-3GPP]
van de Hoef, S., H. Johansson, K., and D. V. Dimarogonas, 3GPP, "Study on enhancement of 3GPP support for 5G V2X
"Fuel-Efficient En Route Formation of Truck Platoons", services", 3GPP TS 22.886 16.2.0, December 2018,
IEEE Transactions on Intelligent Transportation Systems, <https://portal.3gpp.org/desktopmodules/Specifications/
January 2018. SpecificationDetails.aspx?specificationId=3108>.
[Automotive-Sensing] [Truck-Platooning]
Choi, J., Va, V., Gonzalez-Prelcic, N., Daniels, R., R. California Partners for Advanced Transportation Technology
Bhat, C., and R. W. Heath, "Millimeter-Wave Vehicular (PATH), "Truck Platooning",
Communication to Support Massive Automotive Sensing", <https://path.berkeley.edu/research/connected-and-
IEEE Communications Magazine, December 2016. automated-vehicles/truck-platooning>.
[NHTSA-ACAS-Report] [TS-23.285-3GPP]
National Highway Traffic Safety Administration (NHTSA), 3GPP, "Architecture enhancements for V2X services", 3GPP
"Final Report of Automotive Collision Avoidance Systems TS 23.285 16.2.0, December 2019,
(ACAS) Program", DOT HS 809 080, August 2000. <https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3078>.
[CBDN] Kim, J., Kim, S., Jeong, J., Kim, H., Park, J., and T. [TS-23.287-3GPP]
Kim, "CBDN: Cloud-Based Drone Navigation for Efficient 3GPP, "Architecture enhancements for 5G System (5GS) to
Battery Charging in Drone Networks", IEEE Transactions on support Vehicle-to-Everything (V2X) services", 3GPP
Intelligent Transportation Systems, November 2019. TS 23.287 16.2.0, March 2020,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3578>.
[LIFS] Wang, J., Xiong, J., Jiang, H., Jamieson, K., Chen, X., [UAM-ITS] Templin, F., Ed., "Urban Air Mobility Implications for
Fang, D., and C. Wang, "Low Human-Effort, Device-Free Intelligent Transportation Systems", Work in Progress,
Localization with Fine-Grained Subcarrier Information", Internet-Draft, draft-templin-ipwave-uam-its-04, 4 January
IEEE Transactions on Mobile Computing, November 2018. 2021, <https://datatracker.ietf.org/doc/html/draft-
templin-ipwave-uam-its-04>.
[DFC] Jeong, J., Shen, Y., Kim, S., Choe, D., Lee, K., and Y. [Vehicular-BlockChain]
Kim, "DFC: Device-free human counting through WiFi fine- Dorri, A., Steger, M., Kanhere, S., and R. Jurdak,
grained subcarrier information", IET Communications, "BlockChain: A Distributed Solution to Automotive Security
January 2021. and Privacy", IEEE Communications Magazine, Volume 55,
Issue 12, pp. 119-125, DOI 10.1109/MCOM.2017.1700879,
December 2017,
<https://doi.org/10.1109/MCOM.2017.1700879>.
[In-Car-Network] [VEHICULAR-MM]
Lim, H., Volker, L., and D. Herrscher, "Challenges in a Jeong, J., Ed., Mugabarigira, B., Shen, Y., and H. Jung,
Future IP/Ethernet-based In-Car Network for Real-Time "Vehicular Mobility Management for IP-Based Vehicular
Applications", ACM/EDAC/IEEE Design Automation Conference Networks", Work in Progress, Internet-Draft, draft-jeong-
(DAC), June 2011. ipwave-vehicular-mobility-management-09, 4 February 2023,
<https://datatracker.ietf.org/doc/html/draft-jeong-ipwave-
vehicular-mobility-management-09>.
[Scrambler-Attack] [VEHICULAR-ND]
Bloessl, B., Sommer, C., Dressier, F., and D. Eckhoff, Jeong, J., Ed., Shen, Y., Kwon, J., and S. Cespedes,
"The Scrambler Attack: A Robust Physical Layer Attack on "Vehicular Neighbor Discovery for IP-Based Vehicular
Location Privacy in Vehicular Networks", IEEE 2015 Networks", Work in Progress, Internet-Draft, draft-jeong-
International Conference on Computing, Networking and ipwave-vehicular-neighbor-discovery-15, 4 February 2023,
Communications (ICNC), February 2015. <https://datatracker.ietf.org/doc/html/draft-jeong-ipwave-
vehicular-neighbor-discovery-15>.
[Bitcoin] Nakamoto, S., "Bitcoin: A Peer-to-Peer Electronic Cash [VIP-WAVE] Cespedes, S., Lu, N., and X. Shen, "VIP-WAVE: On the
System", URL: https://bitcoin.org/bitcoin.pdf, May 2009. Feasibility of IP Communications in 802.11p Vehicular
Networks", IEEE Transactions on Intelligent Transportation
Systems, Volume 14, Issue 1, pp. 82-97,
DOI 10.1109/TITS.2012.2206387, March 2013,
<https://doi.org/10.1109/TITS.2012.2206387>.
[Vehicular-BlockChain] [WAVE-1609.0]
Dorri, A., Steger, M., Kanhere, S., and R. Jurdak, IEEE, "IEEE Guide for Wireless Access in Vehicular
"BlockChain: A Distributed Solution to Automotive Security Environments (WAVE) - Architecture",
and Privacy", IEEE Communications Magazine, Vol. 55, No. DOI 10.1109/IEEESTD.2014.6755433, IEEE Std 1609.0-2013,
12, December 2017. March 2014,
<https://doi.org/10.1109/IEEESTD.2014.6755433>.
[FCC-ITS-Modification] [WAVE-1609.2]
Federal Communications Commission, "Use of the 5.850-5.925 IEEE, "IEEE Standard for Wireless Access in Vehicular
GHz Band, First Report and Order, Further Notice of Environments - Security Services for Applications and
Proposed Rulemaking, and Order of Proposed Modification, Management Messages", DOI 10.1109/IEEESTD.2016.7426684,
FCC 19-138", Available: https://www.fcc.gov/document/fcc- IEEE Std 1609.2-2016, March 2016,
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Google, "Google Maps", IEEE, "IEEE Standard for Wireless Access in Vehicular
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March 2016,
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2022.
[WIRELESS-ND]
Thubert, P., Ed., "IPv6 Neighbor Discovery on Wireless
Networks", Work in Progress, Internet-Draft, draft-
thubert-6man-ipv6-over-wireless-12, 11 October 2022,
<https://datatracker.ietf.org/doc/html/draft-thubert-6man-
ipv6-over-wireless-12>.
Appendix A. Support of Multiple Radio Technologies for V2V Appendix A. Support of Multiple Radio Technologies for V2V
Vehicular networks may consist of multiple radio technologies such as Vehicular networks may consist of multiple radio technologies, such
DSRC and 5G V2X. Although a Layer-2 solution can provide support for as DSRC and 5G V2X (or LTE V2X). Although a Layer 2 solution can
multihop communications in vehicular networks, the scalability issue provide support for multihop communications in vehicular networks,
related to multihop forwarding still remains when vehicles need to the scalability issue related to multihop forwarding still remains
disseminate or forward packets toward multihop-away destinations. In when vehicles need to disseminate or forward packets toward
addition, the IPv6-based approach for V2V as a network layer protocol destinations that are multiple hops away. In addition, the
can accommodate multiple radio technologies as MAC protocols, such as IPv6-based approach for V2V as a network-layer protocol can
DSRC and 5G V2X. Therefore, the existing IPv6 protocol can be accommodate multiple radio technologies as MAC protocols, such as
augmented through the addition of a virtual interface (e.g., OMNI DSRC and 5G V2X (or LTE V2X). Therefore, the existing IPv6 protocol
[I-D.templin-6man-omni] and DLEP [RFC8175]) and/or protocol changes can be augmented through the addition of a virtual interface (e.g.,
in order to support both wireless single-hop/multihop V2V OMNI [OMNI] and DLEP [RFC8175]) and/or protocol changes in order to
communications and multiple radio technologies in vehicular networks. support both wireless single-hop/multihop V2V communications and
In such a way, vehicles can communicate with each other by V2V multiple radio technologies in vehicular networks. In such a way,
communications to share either an emergency situation or road hazard vehicles can communicate with each other by V2V communications to
information in a highway having multiple kinds of radio technologies. share either an emergency situation or road hazard information on a
highway having multiple radio technologies.
Appendix B. Support of Multihop V2X Networking Appendix B. Support of Multihop V2X Networking
The multihop V2X networking can be supported by RPL (IPv6 Routing The multihop V2X networking can be supported by RPL (IPv6 Routing
Protocol for Low-Power and Lossy Networks) [RFC6550] and Overlay Protocol for Low-Power and Lossy Networks) [RFC6550] and Overlay
Multilink Network Interface (OMNI) [I-D.templin-6man-omni] with AERO Multilink Network Interface [OMNI] with AERO [AERO].
[I-D.templin-6man-aero] .
RPL defines an IPv6 routing protocol for low-power and lossy networks RPL defines an IPv6 routing protocol for Low-Power and Lossy Networks
(LLN), mostly designed for home automation routing, building (LLNs) as being mostly designed for home automation routing, building
automation routing, industrial routing, and urban LLN routing. It automation routing, industrial routing, and urban LLN routing. It
uses a Destination-Oriented Directed Acyclic Graph (DODAG) to uses a Destination-Oriented Directed Acyclic Graph (DODAG) to
construct routing paths for hosts (e.g., IoT devices) in a network. construct routing paths for hosts (e.g., IoT devices) in a network.
The DODAG uses an objective function (OF) for route selection and The DODAG uses an Objective Function (OF) for route selection and
optimization within the network. A user can use different routing optimization within the network. A user can use different routing
metrics to define an OF for a specific scenario. RPL supports metrics to define an OF for a specific scenario. RPL supports
multipoint-to-point, point-to-multipoint, and point-to-point traffic, multipoint-to-point, point-to-multipoint, and point-to-point traffic;
and the major traffic flow is the multipoint-to-point traffic. For and the major traffic flow is the multipoint-to-point traffic. For
example, in a highway scenario, a vehicle may not access an IP-RSU example, in a highway scenario, a vehicle may not access an IP-RSU
directly because of the distance of the DSRC coverage (up to 1 km). directly because of the distance of the DSRC coverage (up to 1 km).
In this case, the RPL can be extended to support a multihop V2I since In this case, the RPL can be extended to support a multihop V2I since
a vehicle can take advantage of other vehicles as relay nodes to a vehicle can take advantage of other vehicles as relay nodes to
reach the IP-RSU. Also, RPL can be extended to support both multihop reach the IP-RSU. Also, RPL can be extended to support both multihop
V2V and V2X in the similar way. V2V and V2X in the similar way.
RPL is primarily designed to minimize the control plane activity, RPL is primarily designed to minimize the control plane activity,
which is the relative amount of routing protocol exchanges versus which is the relative amount of routing protocol exchanges versus
data traffic; this approach is beneficial for situations where the data traffic; this approach is beneficial for situations where the
power and bandwidth are scarce (e.g., an IoT LLN where RPL is power and bandwidth are scarce (e.g., an IoT LLN where RPL is
typically used today), but also in situations of high relative typically used today), but also in situations of high relative
mobility between the nodes in the network (also known as swarming, mobility between the nodes in the network (also known as swarming,
e.g., within a variable set of vehicles with a similar global motion, e.g., within a variable set of vehicles with a similar global motion,
or a variable set of drones flying toward the same direction). or a variable set of drones flying toward the same direction).
To reduce the routing exchanges, RPL leverages a Distance Vector (DV) To reduce the routing exchanges, RPL leverages a Distance Vector (DV)
approach, which does not need a global knowledge of the topology, and approach, which does not need a global knowledge of the topology, and
only optimizes the routes to and from the root, allowing Peer-to-Peer only optimizes the routes to and from the root, allowing peer-to-peer
(P2P) paths to be stretched. Although RPL installs its routes (P2P) paths to be stretched. Although RPL installs its routes
proactively, it only maintains them lazily, that is, in reaction to proactively, it only maintains them lazily, that is, in reaction to
actual traffic, or as a slow background activity. Additionally, RPL actual traffic or as a slow background activity. Additionally, RPL
leverages the concept of an objective function (called OF), which leverages the concept of an OF, which allows adapting the activity of
allows adapting the activity of the routing protocol to use cases, the routing protocol to use cases, e.g., type, speed, and quality of
e.g., type, speed, and quality of the radios. RPL does not need the radios. RPL does not need to converge and provides connectivity
converge, and provides connectivity to most nodes most of the time. to most nodes most of the time. The default route toward the root is
The default route toward the root is maintained aggressively and may maintained aggressively and may change while a packet progresses
change while a packet progresses without causing loops, so the packet without causing loops, so the packet will still reach the root.
will still reach the root. There are two modes for routing in RPL There are two modes for routing in RPL: non-storing mode and storing
such as non-storing mode and storing mode. In non-storing mode, a mode. In non-storing mode, a node inside the mesh or swarm that
node inside the mesh/swarm that changes its point(s) of attachment to changes its point(s) of attachment to the graph informs the root with
the graph informs the root with a single unicast packet flowing along a single unicast packet flowing along the default route, and the
the default route, and the connectivity is restored immediately; this connectivity is restored immediately; this mode is preferable for use
mode is preferable for use cases where Internet connectivity is cases where Internet connectivity is dominant. On the other hand, in
dominant. On the other hand, in storing mode, the routing stretch is storing mode, the routing stretch is reduced for better P2P
reduced, for a better P2P connectivity, while the Internet connectivity, and the Internet connectivity is restored more slowly
connectivity is restored more slowly, during the time for the DV during the time for the DV operation to operate hop-by-hop. While an
operation to operate hop-by-hop. While an RPL topology can quickly RPL topology can quickly scale up and down and fit the needs of
scale up and down and fits the needs of mobility of vehicles, the mobility of vehicles, the total performance of the system will also
total performance of the system will also depend on how quickly a depend on how quickly a node can form an address, join the mesh
node can form an address, join the mesh (including Authentication, (including Authentication, Authorization, and Accounting (AAA)), and
Authorization, and Accounting (AAA)), and manage its global mobility manage its global mobility to become reachable from another node
to become reachable from another node outside the mesh. outside the mesh.
OMNI defines a protocol for the transmission of IPv6 packets over OMNI defines a protocol for the transmission of IPv6 packets over
Overlay Multilink Network Interfaces that are virtual interfaces Overlay Multilink Network Interfaces that are virtual interfaces
governing multiple physical network interfaces. OMNI supports governing multiple physical network interfaces. OMNI supports
multihop V2V communication between vehicles in multiple forwarding multihop V2V communication between vehicles in multiple forwarding
hops via intermediate vehicles with OMNI links. It also supports hops via intermediate vehicles with OMNI links. It also supports
multihop V2I communication between a vehicle and an infrastructure multihop V2I communication between a vehicle and an infrastructure
access point by multihop V2V communication. The OMNI interface access point by multihop V2V communication. The OMNI interface
supports an NBMA link model where multihop V2V and V2I communications supports an NBMA link model where multihop V2V and V2I communications
use each mobile node's ULAs without need for any DAD or MLD use each mobile node's ULAs without need for any DAD or MLD
Messaging. messaging.
In OMNI protocol, an OMNI virtual interface can have a ULA [RFC4193] In the OMNI protocol, an OMNI virtual interface can have a ULA
indeed, but wireless physical interfaces associated with the OMNI [RFC4193] indeed, but wireless physical interfaces associated with
virtual interface are using any prefix. The ULA supports both V2V the OMNI virtual interface can use any prefixes. The ULA supports
and V2I multihop forwarding within the vehicular network (e.g., via a both V2V and V2I multihop forwarding within the vehicular network
VANET routing protocol) while each vehicle can communicate with (e.g., via a VANET routing protocol) while each vehicle can
Internet correspondents using global IPv6 addresses via OMNI communicate with Internet correspondents using IPv6 global addresses
interface encapsulation over the wireless interface. via OMNI interface encapsulation over the wireless interface.
For the control traffic overhead for running both vehicular ND and a For the control traffic overhead for running both vehicular ND and a
VANET routing protocol, the AERO/OMNI approach may avoid this issue VANET routing protocol, the AERO/OMNI approach may avoid this issue
by using MANET routing protocols only (i.e., no multicast of IPv6 ND by using MANET routing protocols only (i.e., no multicast of IPv6 ND
messaging) in the wireless underlay network while applying efficient messaging) in the wireless underlay network while applying efficient
unicast IPv6 ND messaging in the OMNI overlay on an as-needed basis unicast IPv6 ND messaging in the OMNI overlay on an as-needed basis
for router discovery and NUD. This greatly reduces the overhead for for router discovery and NUD. This greatly reduces the overhead for
VANET-wide multicasting while providing agile accommodation for VANET-wide multicasting while providing agile accommodation for
dynamic topology changes. dynamic topology changes.
Appendix C. Support of Mobility Management for V2I Appendix C. Support of Mobility Management for V2I
The seamless application communication between two vehicles or The seamless application communication between two vehicles or
between a vehicle and an infrastructure node requires mobility between a vehicle and an infrastructure node requires mobility
management in vehicular networks. The mobility management schemes management in vehicular networks. The mobility management schemes
include a host-based mobility scheme, network-based mobility scheme, include a host-based mobility scheme, network-based mobility scheme,
and software-defined networking scheme. and software-defined networking scheme.
In the host-based mobility scheme (e.g., MIPv6), an IP-RSU plays a In the host-based mobility scheme (e.g., MIPv6), an IP-RSU plays the
role of a home agent. On the other hand, in the network-based role of a home agent. On the other hand, in the network-based
mobility scheme (e.g., PMIPv6, an MA plays a role of a mobility mobility scheme (e.g., PMIPv6), an MA plays the role of a mobility
management controller such as a Local Mobility Anchor (LMA) in management controller, such as a Local Mobility Anchor (LMA) in
PMIPv6, which also serves vehicles as a home agent, and an IP-RSU 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 plays the role of an access router, such as a Mobile Access Gateway
(MAG) in PMIPv6 [RFC5213]. The host-based mobility scheme needs (MAG) in PMIPv6 [RFC5213]. The host-based mobility scheme needs
client functionality in IPv6 stack of a vehicle as a mobile node for client functionality in the IPv6 stack of a vehicle as a mobile node
mobility signaling message exchange between the vehicle and home for mobility signaling message exchange between the vehicle and home
agent. On the other hand, the network-based mobility scheme does not agent. On the other hand, the network-based mobility scheme does not
need such a client functionality for a vehicle because the network need such client functionality of a vehicle because the network
infrastructure node (e.g., MAG in PMIPv6) as a proxy mobility agent infrastructure node (e.g., MAG in PMIPv6) as a proxy mobility agent
handles the mobility signaling message exchange with the home agent handles the mobility signaling message exchange with the home agent
(e.g., LMA in PMIPv6) for the sake of the vehicle. (e.g., LMA in PMIPv6) for the sake of the vehicle.
There are a scalability issue and a route optimization issue in the There are a scalability issue and a route optimization issue in the
network-based mobility scheme (e.g., PMIPv6) when an MA covers a network-based mobility scheme (e.g., PMIPv6) when an MA covers a
large vehicular network governing many IP-RSUs. In this case, a large vehicular network governing many IP-RSUs. In this case, a
distributed mobility scheme (e.g., DMM [RFC7429]) can mitigate the distributed mobility scheme (e.g., DMM [RFC7429]) can mitigate the
scalability issue by distributing multiple MAs in the vehicular scalability issue by distributing multiple MAs in the vehicular
network such that they are positioned closer to vehicles for route network such that they are positioned closer to vehicles for route
optimization and bottleneck mitigation in a central MA in the optimization and bottleneck mitigation in a central MA in the
network-based mobility scheme. All these mobility approaches (i.e., network-based mobility scheme. All these mobility approaches (i.e.,
a host-based mobility scheme, network-based mobility scheme, and a host-based mobility scheme, network-based mobility scheme, and
distributed mobility scheme) and a hybrid approach of a combination distributed mobility scheme) and a hybrid approach of a combination
of them need to provide an efficient mobility service to vehicles of them need to provide an efficient mobility service to vehicles
moving fast and moving along with the relatively predictable moving fast and moving along with relatively predictable trajectories
trajectories along the roadways. 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) using the concept of Software-Defined Networking (SDN) [RFC7149]
[RFC7149][I-D.ietf-dmm-fpc-cpdp]. Note that Forwarding Policy [FPC-DMM]. Note that Forwarding Policy Configuration (FPC) in
Configuration (FPC) in [I-D.ietf-dmm-fpc-cpdp], which is a flexible [FPC-DMM], which is a flexible mobility management system, can manage
mobility management system, can manage the separation of data-plane the separation of data plane and control plane in DMM. In SDN, the
and control-plane in DMM. In SDN, the control plane and data plane control plane and data plane are separated for the efficient
are separated for the efficient management of forwarding elements management of forwarding elements (e.g., switches and routers) where
(e.g., switches and routers) where an SDN controller configures the an SDN controller configures the forwarding elements in a centralized
forwarding elements in a centralized way and they perform packet way, and they perform packet forwarding according to their forwarding
forwarding according to their forwarding tables that are configured tables that are configured by the SDN controller. An MA as an SDN
by the SDN controller. An MA as an SDN controller needs to controller needs to efficiently configure and monitor its IP-RSUs and
efficiently configure and monitor its IP-RSUs and vehicles for vehicles for mobility management and security services.
mobility management, location management, and security services.
Appendix D. Support of MTU Diversity for IP-based Vehicular Networks Appendix D. Support of MTU Diversity for IP-Based Vehicular Networks
The wireless and/or wired-line links in paths between both mobile The wireless and/or wired-line links in paths between both mobile
nodes and fixed network correspondents may configure a variety of nodes and fixed network correspondents may configure a variety of
Maximum Transmission Units (MTUs), where all IPv6 links are required Maximum Transmission Units (MTUs), where all IPv6 links are required
to support a minimum MTU of 1280 octets and may support larger MTUs. to support a minimum MTU of 1280 octets and may support larger MTUs.
Unfortunately, determining the path MTU (i.e., the minimum link MTU Unfortunately, determining the path MTU (i.e., the minimum link MTU
in the path) has proven to be inefficient and unreliable due to the in the path) has proven to be inefficient and unreliable due to the
uncertain nature of the loss-oriented ICMPv6 messaging service used uncertain nature of the loss-oriented ICMPv6 messaging service used
for path MTU discovery. Recent developments have produced a more for path MTU discovery. Recent developments have produced a more
reliable path MTU determination service for TCP [RFC4821] and UDP reliable path MTU determination service for TCP [RFC4821] and UDP
[RFC8899] however the MTUs discovered are always limited by the most [RFC8899]; however, the MTUs discovered are always limited by the
restrictive link MTU in the path (often 1500 octets or smaller). most restrictive link MTU in the path (often 1500 octets or smaller).
The AERO/OMNI service addresses the MTU issue by introducing a new The AERO/OMNI service addresses the MTU issue by introducing a new
layer in the Internet architecture known as the "OMNI Adaptation layer in the Internet architecture known as the "OMNI Adaptation
Layer (OAL)". The OAL allows end systems that configure an OMNI Layer (OAL)". The OAL allows end systems that configure an OMNI
interface to utilize a full 65535 octet MTU by leveraging the IPv6 interface to utilize a full 65535-octet MTU by leveraging the IPv6
fragmentation and reassembly service during encapsulation to produce fragmentation and reassembly service during encapsulation to produce
fragment sizes that are assured of traversing the path without loss fragment sizes that are assured of traversing the path without loss
due to a size restriction. (This allows end systems to send packets due to a size restriction. Thus, this allows end systems to send
that are often much larger than the actual path MTU.) packets that are often much larger than the actual path MTU.
Performance studies over the course of many decades have proven that Performance studies over the course of many decades have proven that
applications will see greater performance by sending smaller numbers applications will see greater performance by sending smaller numbers
of large packets (as opposed to larger numbers of small packets) even of large packets (as opposed to larger numbers of small packets) even
if fragmentation is needed. The OAL further supports even larger if fragmentation is needed. The OAL further supports even larger
packet sizes through the IP Parcels construct packet sizes through the IP Parcels construct [PARCELS], which
[I-D.templin-intarea-parcels] which provides "packets-in-packet" provides "packets-in-packet" encapsulation for a total size up to 4
encapsulation for a total size up to 4MB. Together, the OAL and IP MB. Together, the OAL and IP Parcels will provide a revolutionary
Parcels will provide a revolutionary new capability for greater new capability for greater efficiency in both mobile and fixed
efficiency in both mobile and fixed networks. On the other hand, due networks. On the other hand, due to the highly dynamic nature of
to the high dynamics of vehicular networks, a high packet loss may vehicular networks, a high packet loss may not be able to be avoided.
not be able to be avoided. The high packet loss on IP parcels can The high packet loss on IP Parcels can simultaneously cause multiple
simultaneously cause multiple TCP sessions to experience packet re- TCP sessions to experience packet retransmissions, session time-out,
transmissions, session time-out, or re-establishment of the sessions. or re-establishment of the sessions. Other protocols, such as MPTCP
Other protocols such as MPTCP and QUIC may also experience the and QUIC, may also experience similar issues. A mechanism for
similar issue. A mechanism for mitigating this issue in OAL and IP mitigating this issue in OAL and IP Parcels should be considered.
Parcels should be considered.
Appendix E. Acknowledgments Acknowledgments
This work was supported by Institute of Information & Communications This work was supported by a grant from the Institute of Information
Technology Planning & Evaluation (IITP) grant funded by the Korea & Communications Technology Planning & Evaluation (IITP) funded by
MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based the Korea MSIT (Ministry of Science and ICT) (R-20160222-002755,
Security Intelligence Technology Development for the Customized Cloud-based Security Intelligence Technology Development for the
Security Service Provisioning). Customized Security Service Provisioning).
This work was supported in part by the MSIT, Korea, under the ITRC This work was supported in part by the MSIT, Korea, under the ITRC
(Information Technology Research Center) support program (IITP- (Information Technology Research Center) support program (IITP-
2022-2017-0-01633) supervised by the IITP. 2022-2017-0-01633) supervised by the IITP.
This work was supported in part by the IITP (2020-0-00395-003, This work was supported in part by the IITP (2020-0-00395-003,
Standard Development of Blockchain based Network Management Standard Development of Blockchain-based Network Management
Automation Technology). Automation Technology).
This work was supported in part by the French research project This work was supported in part by the French research project
DataTweet (ANR-13-INFR-0008) and in part by the HIGHTS project funded DataTweet (ANR-13-INFR-0008) and in part by the HIGHTS project funded
by the European Commission I (636537-H2020). by the European Commission I (636537-H2020).
This work was supported in part by the Cisco University Research This work was supported in part by the Cisco University Research
Program Fund, Grant # 2019-199458 (3696), and by ANID Chile Basal Program Fund, Grant # 2019-199458 (3696), and by ANID Chile Basal
Project FB0008. Project FB0008.
Appendix F. Contributors Contributors
This document is a group work of IPWAVE working group, greatly This document is a group work of the IPWAVE working group, greatly
benefiting from inputs and texts by Rex Buddenberg (Naval benefiting from inputs and texts by Rex Buddenberg (Naval
Postgraduate School), Thierry Ernst (YoGoKo), Bokor Laszlo (Budapest Postgraduate School), Thierry Ernst (YoGoKo), Bokor Laszlo (Budapest
University of Technology and Economics), Jose Santa Lozanoi University of Technology and Economics), Jose Santa Lozanoi
(Universidad of Murcia), Richard Roy (MIT), Francois Simon (Pilot), (Universidad of Murcia), Richard Roy (MIT), Francois Simon (Pilot),
Sri Gundavelli (Cisco), Erik Nordmark, Dirk von Hugo (Deutsche Sri Gundavelli (Cisco), Erik Nordmark (Zededa), Dirk von Hugo
Telekom), Pascal Thubert (Cisco), Carlos Bernardos (UC3M), Russ (Deutsche Telekom), Pascal Thubert (Cisco), Carlos Bernardos (UC3M),
Housley (Vigil Security), Suresh Krishnan (Kaloom), Nancy Cam-Winget Russ Housley (Vigil Security), Suresh Krishnan (Cisco), Nancy Cam-
(Cisco), Fred L. Templin (The Boeing Company), Jung-Soo Park (ETRI), Winget (Cisco), Fred L. Templin (The Boeing Company), Jung-Soo Park
Zeungil (Ben) Kim (Hyundai Motors), Kyoungjae Sun (Soongsil (ETRI), Zeungil (Ben) Kim (Hyundai Motors), Kyoungjae Sun (Soongsil
University), Zhiwei Yan (CNNIC), YongJoon Joe (LSware), Peter E. Yee University), Zhiwei Yan (CNNIC), YongJoon Joe (LSware), Peter E. Yee
(Akayla), and Erik Kline. The authors sincerely appreciate their (Akayla), and Erik Kline (Aalyria). The authors sincerely appreciate
contributions. their contributions.
The following are co-authors of this document:
Nabil Benamar -
Department of Computer Sciences, High School of Technology of Meknes,
Moulay Ismail University, Morocco, Phone: +212 6 70 83 22 36, Email:
benamar73@gmail.com
Sandra Cespedes -
NIC Chile Research Labs, Universidad de Chile, Av. Blanco Encalada The following are coauthors of this document:
1975, Santiago, Chile, Phone: +56 2 29784093, Email:
scespede@niclabs.cl
Jerome Haerri - Nabil Benamar
Department of Computer Sciences,
High School of Technology of Meknes
Moulay Ismail University
Morocco
Phone: +212 6 70 83 22 36
Email: benamar73@gmail.com
Communication Systems Department, EURECOM, Sophia-Antipolis, France, Sandra Cespedes
Phone: +33 4 93 00 81 34, Email: jerome.haerri@eurecom.fr NIC Chile Research Labs
Universidad de Chile
Av. Blanco Encalada 1975
Santiago
Chile
Phone: +56 2 29784093
Email: scespede@niclabs.cl
Dapeng Liu - Jérôme Härri
Communication Systems Department
EURECOM
Sophia-Antipolis
France
Phone: +33 4 93 00 81 34
Email: jerome.haerri@eurecom.fr
Alibaba, Beijing, Beijing 100022, China, Phone: +86 13911788933, Dapeng Liu
Alibaba
Beijing
100022
China
Phone: +86 13911788933
Email: max.ldp@alibaba-inc.com Email: max.ldp@alibaba-inc.com
Tae (Tom) Oh - Tae (Tom) Oh
Department of Information Sciences and Technologies
Department of Information Sciences and Technologies, Rochester Rochester Institute of Technology
Institute of Technology, One Lomb Memorial Drive, Rochester, NY One Lomb Memorial Drive
14623-5603, USA, Phone: +1 585 475 7642, Email: Tom.Oh@rit.edu Rochester, NY 14623-5603
United States of America
Charles E. Perkins - Phone: +1 585 475 7642
Email: Tom.Oh@rit.edu
Futurewei Inc., 2330 Central Expressway, Santa Clara, CA 95050, USA,
Phone: +1 408 330 4586, Email: charliep@computer.org
Alexandre Petrescu -
CEA, LIST, CEA Saclay, Gif-sur-Yvette, Ile-de-France 91190, France, Charles E. Perkins
Phone: +33169089223, Email: Alexandre.Petrescu@cea.fr Futurewei Inc.
2330 Central Expressway,
Santa Clara, CA 95050
United States of America
Phone: +1 408 330 4586,
Email: charliep@computer.org
Yiwen Chris Shen - Alexandre Petrescu
Department of Computer Science & Engineering, Sungkyunkwan CEA, LIST, CEA Saclay
University, 2066 Seobu-Ro, Jangan-Gu, Suwon, Gyeonggi-Do 16419, 91190 Gif-sur-Yvette
Republic of Korea, Phone: +82 31 299 4106, Fax: +82 31 290 7996, France
Email: chrisshen@skku.edu, URI: https://chrisshen.github.io Phone: +33169089223
Email: Alexandre.Petrescu@cea.fr
Michelle Wetterwald - Yiwen Chris Shen
Department of Computer Science & Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Phone: +82 31 299 4106
Email: chrisshen@skku.edu
URI: https://chrisshen.github.io
FBConsulting, 21, Route de Luxembourg, Wasserbillig, Luxembourg Michelle Wetterwald
L-6633, Luxembourg, Email: Michelle.Wetterwald@gmail.com FBConsulting
21, Route de Luxembourg,
L-L-6633, Wasserbillig,
Luxembourg
Email: Michelle.Wetterwald@gmail.com
Author's Address Author's Address
Jaehoon Paul Jeong (editor) Jaehoon Paul Jeong (editor)
Department of Computer Science and Engineering Department of Computer Science and Engineering
Sungkyunkwan University Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu 2066 Seobu-Ro, Jangan-Gu
Suwon Suwon
Gyeonggi-Do Gyeonggi-Do
16419 16419
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