IPWAVE Working Group                                       J. Jeong, Ed.
Internet-Draft                                   Sungkyunkwan University
Intended status: Informational                           October 3, 2019
Expires: April 5, 2020


IP Wireless Access in Vehicular Environments (IPWAVE): Problem Statement
                             and Use Cases
               draft-ietf-ipwave-vehicular-networking-12

Abstract

   This document discusses the problem statement and use cases of IP-
   based vehicular networking for Intelligent Transportation Systems
   (ITS).  The main scenarios of vehicular communications are vehicle-
   to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-
   everything (V2X) communications.  First, this document explains use
   cases using V2V, V2I, and V2X networking.  Next, it makes a problem
   statement about key aspects in IP-based vehicular networking, such as
   IPv6 Neighbor Discovery, Mobility Management, and Security & Privacy.
   For each key aspect, this document specifies requirements in IP-based
   vehicular networking, and suggests the direction of solutions
   satisfying those requirements.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on April 5, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents



Jeong, Ed.                Expires April 5, 2020                 [Page 1]


Internet-Draft          IPWAVE Problem Statement            October 2019


   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  V2V . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  V2I . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  V2X . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   4.  Vehicular Networks  . . . . . . . . . . . . . . . . . . . . .   8
     4.1.  Vehicular Network Architecture  . . . . . . . . . . . . .   9
     4.2.  V2I-based Internetworking . . . . . . . . . . . . . . . .  11
     4.3.  V2V-based Internetworking . . . . . . . . . . . . . . . .  13
   5.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .  14
     5.1.  Neighbor Discovery  . . . . . . . . . . . . . . . . . . .  15
       5.1.1.  Link Model  . . . . . . . . . . . . . . . . . . . . .  16
       5.1.2.  MAC Address Pseudonym . . . . . . . . . . . . . . . .  17
       5.1.3.  Routing . . . . . . . . . . . . . . . . . . . . . . .  18
     5.2.  Mobility Management . . . . . . . . . . . . . . . . . . .  19
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   7.  Informative References  . . . . . . . . . . . . . . . . . . .  21
   Appendix A.  Changes from draft-ietf-ipwave-vehicular-
                networking-11  . . . . . . . . . . . . . . . . . . .  27
   Appendix B.  Acknowledgments  . . . . . . . . . . . . . . . . . .  28
   Appendix C.  Contributors . . . . . . . . . . . . . . . . . . . .  28
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  30

1.  Introduction

   Vehicular networking studies have mainly focused on improving safety
   and efficiency, and also enabling entertainment in vehicular
   networks.  The Federal Communications Commission (FCC) in the US
   allocated wireless channels for Dedicated Short-Range Communications
   (DSRC) [DSRC] in the Intelligent Transportation Systems (ITS) with
   the frequency band of 5.850 - 5.925 GHz (i.e., 5.9 GHz band).  DSRC-
   based wireless communications can support vehicle-to-vehicle (V2V),
   vehicle-to-infrastructure (V2I), and vehicle-to-everything (V2X)
   networking.  The European Union (EU) allocated radio spectrum for
   safety-related and non-safety-related applications of ITS with the
   frequency band of 5.875 - 5.905 GHz, as part of the Commission
   Decision 2008/671/EC [EU-2008-671-EC].



Jeong, Ed.                Expires April 5, 2020                 [Page 2]


Internet-Draft          IPWAVE Problem Statement            October 2019


   For direct inter-vehicular wireless connectivity, IEEE has amended
   WiFi standard 802.11 to enable driving safety services based on DSRC
   for the Wireless Access in Vehicular Environments (WAVE) system.  The
   Physical Layer (L1) and Data Link 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 security aspects, IEEE 1609.3
   [WAVE-1609.3] defines related services at network and transport
   layers, and IEEE 1609.4 [WAVE-1609.4] specifies the multi-channel
   operation.  IEEE 802.11p was first a separate amendment, but was
   later rolled into the base 802.11 standard (IEEE 802.11-2012) as IEEE
   802.11 Outside the Context of a Basic Service Set (OCB) in 2012
   [IEEE-802.11-OCB].

   Along with these WAVE standards, IPv6 [RFC8200] and Mobile IP
   protocols (e.g., MIPv4 [RFC5944], MIPv6 [RFC6275], and Proxy MIPv6
   (PMIPv6) [RFC5213][RFC5844]) can be applied to vehicular networks.
   In addition, ISO has approved a standard specifying the IPv6 network
   protocols and services to be used for Communications Access for Land
   Mobiles (CALM) [ISO-ITS-IPv6].

   This document describes use cases and a problem statement about IP-
   based vehicular networking for ITS, which is named IP Wireless Access
   in Vehicular Environments (IPWAVE).  First, it introduces the use
   cases for using V2V, V2I, and V2X networking in ITS.  Next, it makes
   a problem statement about key aspects in IPWAVE, namely, IPv6
   Neighbor Discovery, Mobility Management, and Security & Privacy.  For
   each key aspect of the problem statement, this document specifies
   requirements in IP-based vehicular networking, and proposes the
   direction of solutions fulfilling those requirements.  This document
   is intended to motivate development of key protocols for IPWAVE.

2.  Terminology

   This document uses the following definitions:

   o  Class-Based Safety Plan: A vehicle can make safety plan by
      classifying the surrounding vehicles into different groups for
      safety purposes according to the geometrical relationship among
      them.  The vehicle groups can be classified as Line-of-Sight
      Unsafe, Non-Line-of-Sight Unsafe, and Safe groups [CASD].

   o  Context-Awareness: A vehicle can be aware of spatial-temporal
      mobility information (e.g., position, speed, direction, and
      acceleration/deceleration) of surrounding vehicles for both safety
      and non-safety uses through sensing or communication [CASD].






Jeong, Ed.                Expires April 5, 2020                 [Page 3]


Internet-Draft          IPWAVE Problem Statement            October 2019


   o  LiDAR: "Light Detection and Ranging".  It is a scanning device to
      measure a distance to an object by emitting pulsed laser light and
      measuring the reflected pulsed light.

   o  Mobility Anchor (MA): A node that maintains IP addresses and
      mobility information of vehicles in a road network to support
      their address autoconfiguration and mobility management with a
      binding table.  An MA has end-to-end connections with RSUs under
      its control.

   o  On-Board Unit (OBU): A node that has physical communication
      devices (e.g., IEEE 802.11-OCB and Cellular V2X (C-V2X)
      [TS-23.285-3GPP]) for wireless communications with other OBUs and
      RSUs, and may be connected to in-vehicle devices or networks.  An
      OBU is mounted on a vehicle.

   o  OCB: "Outside the Context of a Basic Service Set".  It is
      differentiated from the Basic Service Set (BSS) mode in IEEE
      802.11 standard.  A node in OCB mode can directly transmit packets
      to other nodes in its wireless range without the authentication or
      association process defined in BSS mode [IEEE-802.11-OCB].

   o  Platooning: Moving vehicles can be grouped together to reduce air-
      resistance for energy efficiency and reduce the number of drivers
      such that only the leading vehicle has a driver and the other
      vehicles are autonomous vehicles without a driver and closely
      following the leading vehicle [Truck-Platooning].

   o  Road-Side Unit (RSU): A node that has physical communication
      devices (e.g., IEEE 802.11-OCB and C-V2X) for wireless
      communications with vehicles and is also connected to the Internet
      through a router or switch for packet forwarding.  An RSU can
      accommodate multiple routers (or switches) and servers (e.g., DNS
      server and edge computing server) in its internal network as an
      edge computing system.  An RSU is typically deployed on the road
      infrastructure, either at an intersection or in a road segment,
      but may also be located in a car parking area.

   o  Traffic Control Center (TCC): A node that maintains road
      infrastructure information (e.g., RSUs, traffic signals, and loop
      detectors), vehicular traffic statistics (e.g., average vehicle
      speed and vehicle inter-arrival time per road segment), and
      vehicle information (e.g., a vehicle's identifier, position,
      direction, speed, and trajectory as a navigation path).  TCC is
      included in a vehicular cloud for vehicular networks.

   o  Vehicle: A Vehicle in this document is a node that has an OBU for
      wireless communication with other vehicles and RSUs.  It has a



Jeong, Ed.                Expires April 5, 2020                 [Page 4]


Internet-Draft          IPWAVE Problem Statement            October 2019


      radio navigation receiver of Global Positioning System (GPS) for
      efficient navigation.

   o  Vehicular Ad Hoc Network (VANET): A network that consists of
      vehicles interconnected by wireless communication.  Two vehicles
      in a VANET can communicate with each other using other vehicles as
      relays even where they are out of one-hop wireless communication
      range.

   o  Vehicular Cloud: A cloud infrastructure for vehicular networks,
      having compute nodes, storage nodes, and network forwarding
      elements (e.g., switch and router).

   o  Vehicle Detection Loop (i.e., Loop Detector): An inductive device
      used for detecting vehicles passing or arriving at a certain
      point, for instance, at an intersection with traffic lights or at
      a ramp toward a highway.  The relatively crude nature of the
      loop's structure means that only metal masses above a certain size
      are capable of triggering the detection.

   o  V2I2P: "Vehicle to Infrastructure to Pedestrian".

   o  V2I2V: "Vehicle to Infrastructure to Vehicle".

   o  WAVE: "Wireless Access in Vehicular Environments" [WAVE-1609.0].

3.  Use Cases

   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
   networking, but include Vehicle-to-Pedestrian (V2P) and Vehicle-to-
   Device (V2D).

3.1.  V2V

   The use cases of V2V networking discussed in this section include

   o  Context-aware navigation for driving safety and collision
      avoidance;

   o  Cooperative adaptive cruise control in an urban roadway;

   o  Platooning in a highway;

   o  Cooperative environment sensing.

   These four techniques will be important elements for self-driving
   vehicles.



Jeong, Ed.                Expires April 5, 2020                 [Page 5]


Internet-Draft          IPWAVE Problem Statement            October 2019


   Context-Aware Safety Driving (CASD) navigator [CASD] can help drivers
   to drive safely by alerting the drivers about dangerous obstacles and
   situations.  That is, CASD navigator displays obstacles or
   neighboring vehicles relevant to possible collisions in real-time
   through V2V networking.  CASD provides vehicles with a class-based
   automatic safety action plan, which considers three situations,
   namely, the Line-of-Sight unsafe, Non-Line-of-Sight unsafe, and safe
   situations.  This action plan can be put into action among multiple
   vehicles using V2V networking.

   Cooperative Adaptive Cruise Control (CACC) [CA-Cruise-Control] helps
   vehicles to adapt their speed autonomously through V2V communication
   among vehicles according to the mobility of their predecessor and
   successor vehicles in an urban roadway or a highway.  Thus, CACC can
   help adjacent vehicles to efficiently adjust their speed in an
   interactive way through V2V networking in order to avoid collision.

   Platooning [Truck-Platooning] allows a series of vehicles (e.g.,
   trucks) to follow each other very closely.  Trucks can use V2V
   communication in addition to forward sensors in order to maintain
   constant clearance between two consecutive vehicles at very short
   gaps (from 3 meters to 10 meters).  Platooning can maximize the
   throughput of vehicular traffic in a highway and reduce the gas
   consumption because the leading vehicle can help the following
   vehicles to experience less air resistance.

   Cooperative-environment-sensing use cases suggest that vehicles can
   share environmental information from various vehicle-mounted sensors,
   such as radars, LiDARs, and cameras with other vehicles and
   pedestrians.  [Automotive-Sensing] introduces a millimeter-wave
   vehicular communication for massive automotive sensing.  A lot of
   data can be generated by those sensors, and these data typically need
   to be routed to different destinations.  In addition, from the
   perspective of driverless vehicles, it is expected that driverless
   vehicles can be mixed with driver-operated vehicles.  Through the
   cooperative environment sensing, driver-operated vehicles can use
   environmental information sensed by driverless vehicles for better
   interaction with the other vehicles and environment.

3.2.  V2I

   The use cases of V2I networking discussed in this section include

   o  Navigation service;

   o  Energy-efficient speed recommendation service;

   o  Accident notification service.



Jeong, Ed.                Expires April 5, 2020                 [Page 6]


Internet-Draft          IPWAVE Problem Statement            October 2019


   A navigation service, for example, the Self-Adaptive Interactive
   Navigation Tool (SAINT) [SAINT], using V2I networking interacts with
   TCC for the large-scale/long-range road traffic optimization and can
   guide individual vehicles for appropriate navigation paths in real
   time.  The enhanced version of SAINT [SAINTplus] can give fast moving
   paths to emergency vehicles (e.g., ambulance and fire engine) to let
   them reach an accident spot while redirecting other vehicles near the
   accident spot into efficient detour paths.

   A TCC can recommend an energy-efficient speed to a vehicle that
   depends on its traffic environment.  [Fuel-Efficient] studies fuel-
   efficient route and speed plans for platooned trucks.

   The emergency communication between accident vehicles (or emergency
   vehicles) and TCC can be performed via either RSU or 4G-LTE networks.
   The First Responder Network Authority (FirstNet) [FirstNet] is
   provided by the US government to establish, operate, and maintain an
   interoperable public safety broadband network for safety and security
   network services, e.g., emergency calls.  The construction of the
   nationwide FirstNet network requires each state in the US to have a
   Radio Access Network (RAN) that will connect to the FirstNet's
   network core.  The current RAN is mainly constructed by 4G-LTE for
   the communication between a vehicle and an infrastructure node (i.e.,
   V2I) [FirstNet-Report], but it is expected that DSRC-based vehicular
   networks [DSRC] will be available for V2I and V2V in near future.

3.3.  V2X

   The use case of V2X networking discussed in this section is
   pedestrian protection service.

   A pedestrian protection service, such as Safety-Aware Navigation
   Application (SANA) [SANA], using V2I2P networking can reduce the
   collision of a vehicle and a pedestrian carrying a smartphone
   equipped with a network device for wireless communication (e.g.,
   WiFi) with an RSU.  Vehicles and pedestrians can also communicate
   with each other via an RSU that delivers scheduling information for
   wireless communication in order to save the smartphones' battery
   through sleeping mode.

   For Vehicle-to-Pedestrian (V2P), a vehicle can directly communicate
   with a pedestrian's smartphone by V2X without RSU relaying.  Light-
   weight mobile nodes such as bicycles may also communicate directly
   with a vehicle for collision avoidance using V2V.







Jeong, Ed.                Expires April 5, 2020                 [Page 7]


Internet-Draft          IPWAVE Problem Statement            October 2019


4.  Vehicular Networks

   This section describes a vehicular network architecture supporting
   V2V, V2I, and V2X communications in vehicular networks.  Also, it
   describes an internal network within a vehicle or RSU, and the
   internetworking between the internal networks via DSRC links.

                     Traffic Control Center in Vehicular Cloud
                    *******************************************
                   *                                           *
                  *             +-----------------+             *
                 *              | Mobility Anchor |              *
                 *              +-----------------+              *
                 *                       ^                       *
                  *                      | Ethernet             *
                   *                     v                     *
                    *******************************************
                    ^                  ^                     ^
                    | Ethernet         | Ethernet            | Ethernet
                    |                  |                     |
                    v                  v                     v
               +--------+ Ethernet +--------+  Ethernet  +--------+
               |  RSU1  |<-------->|  RSU2  |<---------->|  RSU3  |
               +--------+          +--------+            +--------+
                  ^                     ^                    ^
                  :                     :                    :
           +-----------------+ +-----------------+   +-----------------+
           |      : V2I      | |        : V2I    |   |       : V2I     |
           |      v          | |        v        |   |       v         |
+--------+ |   +--------+    | |   +--------+    |   |   +--------+    |
|Vehicle1|===> |Vehicle2|===>| |   |Vehicle3|===>|   |   |Vehicle4|===>|
+--------+<...>+--------+<........>+--------+    |   |   +--------+    |
           V2V     ^         V2V        ^        |   |        ^        |
           |       : V2V     | |        : V2V    |   |        : V2V    |
           |       v         | |        v        |   |        v        |
           |  +--------+     | |   +--------+    |   |    +--------+   |
           |  |Vehicle5|===> | |   |Vehicle6|===>|   |    |Vehicle7|==>|
           |  +--------+     | |   +--------+    |   |    +--------+   |
           +-----------------+ +-----------------+   +-----------------+
                 Subnet1              Subnet2              Subnet3
                (Prefix1)            (Prefix2)            (Prefix3)

        <----> Wired Link   <....> Wireless Link   ===> Moving Direction

   Figure 1: A Vehicular Network Architecture for V2I and V2V Networking






Jeong, Ed.                Expires April 5, 2020                 [Page 8]


Internet-Draft          IPWAVE Problem Statement            October 2019


4.1.  Vehicular Network Architecture

   Figure 1 shows an architecture for V2I and V2V networking in a road
   network.  The vehicular network architecture contains vehicles, RSUs,
   Vehicular Cloud, Traffic Control Center, and Mobility Anchor as
   components.  However, some components in the vehicular network
   architecture may not be needed for vehicular networking, such as
   Vehicular Cloud, Traffic Control Center, and Mobility Anchor.

   As shown in this figure, RSUs as routers and vehicles with OBU have
   wireless media interfaces for VANET.  Furthermore, the wireless media
   interfaces are autoconfigured with a global IPv6 prefix (e.g.,
   2001:DB8:1:1::/64) to support both V2V and V2I networking.  Note that
   2001:DB8::/32 is a documentation prefix [RFC3849] for example
   prefixes in this document, and also that any routable IPv6 address
   needs to be routable in a VANET and a vehicular network including
   RSUs.

   For IPv6 packets transported over IEEE 802.11-OCB,
   [IPv6-over-802.11-OCB] specifies several details, including Maximum
   Transmission Unit (MTU), frame format, link-local address, address
   mapping for unicast and multicast, stateless autoconfiguration, and
   subnet structure.  An Ethernet Adaptation (EA) layer is in charge of
   transforming some parameters between IEEE 802.11 MAC layer and IPv6
   network layer, which is located between IEEE 802.11-OCB's logical
   link control layer and IPv6 network layer.  This IPv6 over 802.11-OCB
   can be used for both V2V and V2I in IP-based vehicular networks.

   In Figure 1, three RSUs (RSU1, RSU2, and RSU3) are deployed in the
   road network and are connected to a Vehicular Cloud through the
   Internet.  A Traffic Control Center (TCC) is connected to the
   Vehicular Cloud for the management of RSUs and vehicles in the road
   network.  A Mobility Anchor (MA) can be located in the TCC as its key
   component for the mobility management of vehicles.  Vehicle2,
   Vehicle3, and Vehicle4 are wirelessly connected to RSU1, RSU2, and
   RSU3, respectively.  The three wireless networks of RSU1, RSU2, and
   RSU3 can belong to three different subnets (i.e., Subnet1, Subnet2,
   and Subnet3), respectively.  Those three subnets use three different
   prefixes (i.e., Prefix1, Prefix2, and Prefix3).

   A single subnet prefix can span multiple vehicles in VANET.  For
   example, in Figure 1, for Prefix 1, three vehicles (i.e., Vehicle1,
   Vehicle2, and Vehicle5) can construct a connected VANET.  Also, for
   Prefix 2, two vehicles (i.e., Vehicle3 and Vehicle6) can construct
   another connected VANET, and for Prefix 3, two vehicles (i.e.,
   Vehicle4 and Vehicle7) can construct another connected VANET.





Jeong, Ed.                Expires April 5, 2020                 [Page 9]


Internet-Draft          IPWAVE Problem Statement            October 2019


   In wireless subnets in vehicular networks (e.g., Subnet1 and Subnet2
   in Figure 1), vehicles can construct a connected VANET (with an
   arbitrary graph topology) and can communicate with each other via V2V
   communication.  Vehicle1 can communicate with Vehicle2 via V2V
   communication, and Vehicle2 can communicate with Vehicle3 via V2V
   communication because they are within the wireless communication
   range for each other.  On the other hand, Vehicle3 can communicate
   with Vehicle4 via the vehicular infrastructure (i.e., RSU2 and RSU3)
   by employing V2I (i.e., V2I2V) communication because they are not
   within the wireless communication range for each other.

   In vehicular networks, asymmetric links sometimes exist and must be
   considered for wireless communications.  In vehicular networks, the
   control plane can be separated from the data plane for efficient
   mobility management and data forwarding.  The mobility information of
   a GPS receiver mounted in its vehicle (e.g., position, speed, and
   direction) can be used to accommodate mobility-aware proactive
   protocols.  Vehicles can use the TCC as their Home Network having a
   home agent for mobility management as in MIPv6 [RFC6275] and PMIPv6
   [RFC5213], so the TCC maintains the mobility information of vehicles
   for location management.  IP tunneling over the wireless link should
   be avoided for performance efficiency.





























Jeong, Ed.                Expires April 5, 2020                [Page 10]


Internet-Draft          IPWAVE Problem Statement            October 2019


                                                    +-----------------+
                           (*)<........>(*)  +----->| Vehicular Cloud |
          2001:DB8:1:1::/64 |            |   |      +-----------------+
   +------------------------------+  +---------------------------------+
   |                        v     |  |   v   v                         |
   | +-------+ +------+ +-------+ |  | +-------+ +------+ +-------+    |
   | | Host1 | | DNS1 | |Router1| |  | |Router3| | DNS2 | | Host3 |    |
   | +-------+ +------+ +-------+ |  | +-------+ +------+ +-------+    |
   |     ^        ^         ^     |  |     ^         ^        ^        |
   |     |        |         |     |  |     |         |        |        |
   |     v        v         v     |  |     v         v        v        |
   | ---------------------------- |  | ------------------------------- |
   | 2001:DB8:10:1::/64 ^         |  |     ^ 2001:DB8:20:1::/64        |
   |                    |         |  |     |                           |
   |                    v         |  |     v                           |
   | +-------+      +-------+     |  | +-------+ +-------+   +-------+ |
   | | Host2 |      |Router2|     |  | |Router4| |Server1|...|ServerN| |
   | +-------+      +-------+     |  | +-------+ +-------+   +-------+ |
   |     ^              ^         |  |     ^         ^           ^     |
   |     |              |         |  |     |         |           |     |
   |     v              v         |  |     v         v           v     |
   | ---------------------------- |  | ------------------------------- |
   |      2001:DB8:10:2::/64      |  |       2001:DB8:20:2::/64        |
   +------------------------------+  +---------------------------------+
      Vehicle1 (Moving Network1)            RSU1 (Fixed Network1)

      <----> Wired Link   <....> Wireless Link   (*) Antenna

     Figure 2: Internetworking between Vehicle Network and RSU Network

4.2.  V2I-based Internetworking

   This section discusses the internetworking between a vehicle's
   internal network (i.e., moving network) and an RSU's internal network
   (i.e., fixed network) via V2I communication.  Note that an RSU can
   accommodate multiple routers (or switches) and servers (e.g., DNS
   server and edge computing server) in its internal network as an edge
   computing system.

   A vehicle's internal network often uses Ethernet to interconnect
   control units in the vehicle.  The internal network also supports
   WiFi and Bluetooth to accommodate a driver's and passenger's mobile
   devices (e.g., smartphone or tablet).  It is reasonable to consider
   the interaction between the internal network and an external network
   within another vehicle or RSU.

   As shown in Figure 2, the vehicle's moving network and the RSU's
   fixed network are self-contained networks having multiple subnets and



Jeong, Ed.                Expires April 5, 2020                [Page 11]


Internet-Draft          IPWAVE Problem Statement            October 2019


   having an edge router for the communication with another vehicle or
   RSU.  Internetworking between two internal networks via V2I
   communication requires an exchange of network prefix and other
   parameters through a prefix discovery mechanism, such as ND-based
   prefix discovery [ID-Vehicular-ND].  For ND-based prefix discovery,
   network prefixes and parameters should be registered with a vehicle's
   router and an RSU router with an external network interface in
   advance.

   For an IP communication between a vehicle and an RSU or between two
   neighboring vehicles, the network parameter discovery collects
   information relevant to the link layer, MAC layer, and IP layer.  The
   link layer information includes wireless link layer parameters and
   transmission power level.  The MAC layer information includes the MAC
   address of an external network interface for the internetworking with
   another vehicle or RSU.  The IP layer information includes the IP
   address and prefix of an external network interface for the
   internetworking with another vehicle or RSU.

   Once the network parameter discovery and prefix exchange operations
   have been performed, packets can be transmitted between the vehicle's
   moving network and the RSU's fixed network.  A DNS service should be
   supported for the DNS name resolution of in-vehicle devices within a
   vehicle's internal network as well as for the DNS name resolution of
   those devices from a remote host in the Internet (e.g., a customer's
   web browser and an automotive service center system).  The DNS names
   of in-vehicle devices and their service names can be registered with
   a DNS server in a vehicle or an RSU, as shown in Figure 2.

   Figure 2 also shows internetworking between the vehicle's moving
   network and the RSU's fixed network.  There exists an internal
   network (Moving Network1) inside Vehicle1.  Vehicle1 has the DNS
   Server (DNS1), the two hosts (Host1 and Host2), and the two routers
   (Router1 and Router2).  There exists another internal network (Fixed
   Network1) inside RSU1.  RSU1 has the DNS Server (DNS2), one host
   (Host3), the two routers (Router3 and Router4), and the collection of
   servers (Server1 to ServerN) for various services in the road
   networks, such as the emergency notification and navigation.
   Vehicle1's Router1 (a mobile router) and RSU1's Router3 (a fixed
   router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for
   V2I networking.  Thus, one host (Host1) in Vehicle1 can communicate
   with one server (Server1) in RSU1 for a vehicular service through
   Vehicle1's moving network, a wireless link between Vehicle1 and RSU1,
   and RSU1's fixed network.







Jeong, Ed.                Expires April 5, 2020                [Page 12]


Internet-Draft          IPWAVE Problem Statement            October 2019


                           (*)<..........>(*)
          2001:DB8:1:1::/64 |              |
   +------------------------------+  +------------------------------+
   |                        v     |  |     v                        |
   | +-------+ +------+ +-------+ |  | +-------+ +------+ +-------+ |
   | | Host1 | | DNS1 | |Router1| |  | |Router5| | DNS3 | | Host4 | |
   | +-------+ +------+ +-------+ |  | +-------+ +------+ +-------+ |
   |     ^        ^         ^     |  |     ^         ^        ^     |
   |     |        |         |     |  |     |         |        |     |
   |     v        v         v     |  |     v         v        v     |
   | ---------------------------- |  | ---------------------------- |
   | 2001:DB8:10:1::/64 ^         |  |         ^ 2001:DB8:30:1::/64 |
   |                    |         |  |         |                    |
   |                    v         |  |         v                    |
   | +-------+      +-------+     |  |     +-------+      +-------+ |
   | | Host2 |      |Router2|     |  |     |Router6|      | Host5 | |
   | +-------+      +-------+     |  |     +-------+      +-------+ |
   |     ^              ^         |  |         ^              ^     |
   |     |              |         |  |         |              |     |
   |     v              v         |  |         v              v     |
   | ---------------------------- |  | ---------------------------- |
   |      2001:DB8:10:2::/64      |  |       2001:DB8:30:2::/64     |
   +------------------------------+  +------------------------------+
      Vehicle1 (Moving Network1)        Vehicle2 (Moving Network2)

      <----> Wired Link   <....> Wireless Link   (*) Antenna

          Figure 3: Internetworking between Two Vehicle Networks

4.3.  V2V-based Internetworking

   This section discusses the internetworking between the moving
   networks of two neighboring vehicles via V2V communication.

   Figure 3 shows internetworking between the moving networks of two
   neighboring vehicles.  There exists an internal network (Moving
   Network1) inside Vehicle1.  Vehicle1 has the DNS Server (DNS1), the
   two hosts (Host1 and Host2), and the two routers (Router1 and
   Router2).  There exists another internal network (Moving Network2)
   inside Vehicle2.  Vehicle2 has the DNS Server (DNS3), the two hosts
   (Host4 and Host5), and the two routers (Router5 and Router6).
   Vehicle1's Router1 (a mobile router) and Vehicle2's Router5 (a mobile
   router) use 2001:DB8:1:1::/64 for an external link (e.g., DSRC) for
   V2V networking.  Thus, one host (Host1) in Vehicle1 can communicate
   with one host (Host4) in Vehicle1 for a vehicular service through
   Vehicle1's moving network, a wireless link between Vehicle1 and
   Vehicle2, and Vehicle2's moving network.




Jeong, Ed.                Expires April 5, 2020                [Page 13]


Internet-Draft          IPWAVE Problem Statement            October 2019


        (*)<..................>(*)<..................>(*)
         |                      |                      |
   +-----------+          +-----------+          +-----------+
   |           |          |           |          |           |
   | +-------+ |          | +-------+ |          | +-------+ |
   | |Router1| |          | |Router5| |          | |Router7| |
   | +-------+ |          | +-------+ |          | +-------+ |
   |           |          |           |          |           |
   | +-------+ |          | +-------+ |          | +-------+ |
   | | Host1 | |          | | Host4 | |          | | Host6 | |
   | +-------+ |          | +-------+ |          | +-------+ |
   |           |          |           |          |           |
   +-----------+          +-----------+          +-----------+
      Vehicle1               Vehicle2               Vehicle3

      <....> Wireless Link   (*) Antenna

      Figure 4: Multihop Internetworking between Two Vehicle Networks

   Figure 4 shows multihop internetworking between the moving networks
   of two vehicles in the same VANET.  For example, Host1 in Vehicle1
   can communicate with Host6 in Vehicle3 via Router 5 in Vehicle2 that
   is an intermediate vehicle being connected to Vehicle1 and Vehicle3
   in a linear topology as shown in the figure.

5.  Problem Statement

   In order to specify protocols using the abovementioned architecture
   for VANETs, IPv6 core protocols have to be adapted to overcome
   certain challenging aspects of vehicular networking.  Since the
   vehicles are likely to be moving at great speed, protocol exchanges
   need to be completed in a time relatively small compared to the
   lifetime of a link between a vehicle and an RSU, or between two
   vehicles.  This has a major impact on IPv6 neighbor discovery.
   Mobility management is also vulnerable to disconnections that occur
   before the completion of identity verification and tunnel management.
   This is especially true given the unreliable nature of wireless
   communications.  Finally, and perhaps most importantly, proper
   authorization for vehicular protocol messages must be assured in
   order to prevent false reports of accidents or other mishaps on the
   road, which would cause horrific misery in modern urban environments.
   This section presents key topics such as neighbor discovery and
   mobility management.








Jeong, Ed.                Expires April 5, 2020                [Page 14]


Internet-Draft          IPWAVE Problem Statement            October 2019


5.1.  Neighbor Discovery

   IPv6 Neighbor Discovery (IPv6 ND) [RFC4861][RFC4862] is a core part
   of the IPv6 protocol suite.  IPv6 ND is designed for point-to-point
   links and transit links (e.g., Ethernet).  It assumes an efficient
   and reliable support of multicast from the link layer for various
   network operations such as MAC Address Resolution (AR) and Duplicate
   Address Detection (DAD).

   DAD and ND-related parameters (e.g., Router Lifetime) need to be
   extended to vehicular networking (e.g., V2V, V2I, and V2X).  Vehicles
   move quickly within the communication coverage of any particular
   vehicle or RSU.  Before the vehicles can exchange application
   messages with each other, they need to be configured with a link-
   local IPv6 address or a global IPv6 address, and run IPv6 ND.

   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
   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
   ownership.  However, the partitioning and merging of VANETs makes
   this assumption frequently invalid in vehicular networks.  The
   merging and partitioning of VANETs occurs frequently in vehicular
   networks.  This merging and partitioning should be considered for the
   IPv6 Neighbor Discovery (e.g., SLAAC).  Due to the merging of VANETs,
   two IPv6 addresses may conflict with each other though they were
   unique before the merging.  Also, the partitioning of a VANET may
   make vehicles with the same prefix be physically unreachable.  Also,
   SLAAC should be extended to prevent IPv6 address duplication due to
   the merging of VANETs.  According to the merging and partitioning, a
   destination vehicle (as an IP host) should be distinguished as either
   an on-link host or off-link host even though the source vehicle uses
   the same prefix with the destination vehicle.

   The vehicular networks need to support a vehicular-network-wide DAD
   by defining a scope that is compatible with the legacy DAD, and two
   vehicles can communicate with each other when there exists a
   communication path over VANET or a combination of VANETs and RSUs, as
   shown in Figure 1.  By using the vehicular-network-wide DAD, vehicles
   can assure that their IPv6 addresses are unique in the vehicular
   network whenever they are connected to the vehicular infrastructure
   or become disconnected from it in the form of VANET.  A vehicular
   infrastructure having RSUs and an MA can participate in the
   vehicular-network-wide DAD for the sake of vehicles [RFC6775].  For
   the vehicle as an IPv6 node, deriving a unique IPv6 address from a
   globally unique MAC address creates a privacy issue.  Refer to
   Section 6 for the discussion about such a privacy issue.




Jeong, Ed.                Expires April 5, 2020                [Page 15]


Internet-Draft          IPWAVE Problem Statement            October 2019


   ND time-related parameters such as router lifetime and Neighbor
   Advertisement (NA) interval should be adjusted for high-speed
   vehicles and vehicle density.  As vehicles move faster, the NA
   interval should decrease (e.g., from 1 sec to 0.5 sec) for the NA
   messages to reach the neighboring vehicles promptly.  Also, as
   vehicle density is higher, the NA interval should increase (e.g.,
   from 0.5 sec to 1 sec) for the NA messages to reduce collision
   probability with other NA messages.

   According to a report from the National Highway Traffic Safety
   Administration (NHTSA) [NHTSA-ACAS-Report], an extra 0.5 second of
   warning time can prevent about 60% of the collisions of vehicles
   moving closely in a roadway.  A warning message should be exchanged
   every 0.5 second.  Thus, if the ND messages (e.g., NS and NA) are
   used as warning messages, they should be exchanged every 0.5 second.

   For IP-based safety applications (e.g., context-aware navigation,
   adaptive cruise control, and platooning) in vehicular network, this
   bounded data delivery is critical.  Implementations for such
   applications are not available yet.  ND needs work to support IP-
   based safety applications.

5.1.1.  Link Model

   IPv6 protocols work under certain assumptions for the link model that
   do not necessarily hold in a vehicular wireless link [VIP-WAVE]
   [RFC5889].  For instance, some IPv6 protocols assume symmetry in the
   connectivity among neighboring interfaces [RFC6250].  However,
   interference and different levels of transmission power may cause
   asymmetric links to appear in vehicular wireless links.  As a result,
   a new vehicular link model should consider the asymmetry of
   dynamically changing vehicular wireless links.

   There is a relationship between a link and a prefix, besides the
   different scopes that are expected from the link-local and global
   types of IPv6 addresses.  In an IPv6 link, it is assumed that all
   interfaces which are configured with the same subnet prefix and with
   on-link bit set can communicate with each other on an IP link.
   However, the vehicular link model needs to define the relationship
   between a link and a prefix, considering the dynamics of wireless
   links and the characteristics of VANET.

   A VANET can have multiple links between pairs of vehicles within
   wireless communication range, as shown in Figure 4.  When two
   vehicles belong to the same VANET, but they are out of wireless
   communication range, they cannot communicate directly with each
   other.  Suppose that a global-scope IPv6 prefix is assigned to VANETs
   in vehicular networks.  Even though two vehicles in the same VANET



Jeong, Ed.                Expires April 5, 2020                [Page 16]


Internet-Draft          IPWAVE Problem Statement            October 2019


   configure their IPv6 addresses with the same IPv6 prefix, they may
   not communicate with each other not in a one hop in the same VANET
   because of the multihop network connectivity.  Thus, in this case,
   the concept of an on-link IPv6 prefix does not hold because two
   vehicles with the same on-link IPv6 prefix cannot communicate
   directly with each other.  Also, when two vehicles are located in two
   different VANETs with the same IPv6 prefix, they cannot communicate
   with each other.  When these two VANETs converge to one VANET, the
   two vehicles can communicate with each other in a multihop fashion.

   From the previous observation, a vehicular link model should consider
   the frequent partitioning and merging of VANETs due to vehicle
   mobility.  Therefore, the vehicular link model needs to use an on-
   link prefix and off-link prefix according to the one-hop reachability
   among the vehicles in an appropriate way.  If the vehicles with the
   same prefix are reachable with each other in one hop, the prefix
   should be on-link.  On the other hand, if some of the vehicles with
   the same prefix are not reachable with each other in one hop due to
   either the multi-hop topology in the VANET or multiple partitions,
   the prefix should be off-link.

   The vehicular link model needs to support the multihop routing in a
   connected VANET where the vehicles with the same global-scope IPv6
   prefix are connected in one hop or multiple hops.  It also needs to
   support the multihop routing in multiple connected VANETs via an RSU
   that has the wireless connectivity with each VANET.  For example, in
   Figure 1, suppose that Vehicle1, Vehicle2, and Vehicle3 are
   configured with their IPv6 addresses based on the same global-scope
   IPv6 prefix.  Vehicle1 and Vehicle3 can also communicate with each
   other via either multi-hop V2V or multi-hop V2I2V.  When two vehicles
   of Vehicle1 and Vehicle3 are connected in a VANET, it will be more
   efficient for them to communicate with each other via VANET rather
   than RSUs.  On the other hand, when the two vehicles of Vehicle1 and
   Vehicle3 are far away from the communication range in separate VANETs
   and under two different RSUs, they can communicate with each other
   through the relay of RSUs via V2I2V.  Thus, two separate VANETs can
   merge into one network via RSU(s).  Also, newly arriving vehicles can
   merge two separate VANETs into one VANET if they can play a role of a
   relay node for those VANETs.

5.1.2.  MAC Address Pseudonym

   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
   address can be changed periodically.  However, although such a
   pseudonym of a MAC address can protect some extent of privacy of a
   vehicle, it may not be able to resist attacks on vehicle
   identification by other fingerprint information, for example, the



Jeong, Ed.                Expires April 5, 2020                [Page 17]


Internet-Draft          IPWAVE Problem Statement            October 2019


   scrambler seed embedded in IEEE 802.11-OCB frames [Scrambler-Attack].
   The pseudonym of a MAC address affects an IPv6 address based on the
   MAC address, and a transport-layer (e.g., TCP) session with an IPv6
   address pair.  However, the pseudonym handling is not implemented and
   tested yet for applications on IP-based vehicular networking.

   In the ETSI standards, for the sake of security and privacy, an ITS
   station (e.g., vehicle) can use pseudonyms for its network interface
   identities (e.g., MAC address) and the corresponding IPv6 addresses
   [Identity-Management].  Whenever the network interface identifier
   changes, the IPv6 address based on the network interface identifier
   should be updated, and the uniqueness of the address should be
   performed through the DAD procedure.  For vehicular networks with
   high mobility and density, this DAD should be performed efficiently
   with minimum overhead so that the vehicles can exchange warning
   messages with each other every 0.5 second [NHTSA-ACAS-Report].

   For the continuity of an end-to-end (E2E) transport-layer (e.g., TCP,
   UDP, and SCTP) session, with a mobility management scheme (e.g.,
   MIPv6 and PMIPv6), the new IP address for the transport-layer session
   can be notified to an appropriate end point, and the packets of the
   session should be forwarded to their destinations with the changed
   network interface identifier and IPv6 address.  This mobility
   management overhead for pseudonyms should be minimized for efficient
   operations in vehicular networks having lots of vehicles.

5.1.3.  Routing

   For multihop V2V communications in either a VANET or VANETs via RSUs,
   a vehicular ad hoc routing protocol (e.g., AODV and OLSRv2) may 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
   both vehicular ND and a vehicular ad hoc routing protocol in terms of
   control traffic overhead [ID-Multicast-Problems].

   The merging of the IPv6 Neighbor Discovery and a VANET routing
   protocol allows the efficient wireless channel utilization.  A
   routing protocol for VANET may cause redundant wireless frames in the
   air to check the neighborhood of each vehicle and compute the routing
   information in VANET with a dynamic network topology if the IPv6 ND
   is used to check the neighborhood of each vehicle, and can be
   extended to compute each vehicle's routing table in VANET.

   Vehicular ND can be extended to accommodate routing functionality
   with a prefix discovery option.  The ND extension can allow vehicles
   to exchange their prefixes in a multihop fashion [ID-Vehicular-ND].
   With the exchanged prefixes, they can compute their routing table (or




Jeong, Ed.                Expires April 5, 2020                [Page 18]


Internet-Draft          IPWAVE Problem Statement            October 2019


   IPv6 ND's neighbor cache) for the VANETs with a distance-vector
   algorithm [Intro-to-Algorithms].

5.2.  Mobility Management

   The seamless connectivity and timely data exchange between two end
   points requires an efficient mobility management including location
   management and handover.  Most of vehicles are equipped with a GPS
   receiver as part of a dedicated navigation system or a corresponding
   smartphone App.  The GPS receiver may not provide vehicles with
   accurate location information in adverse, local environments such as
   building area and tunnel.  The location precision can be improved by
   the assistance from the RSUs or a cellular system with a GPS receiver
   for location information.

   With a GPS navigator, an efficient mobility management will be
   possible by vehicles periodically reporting their current position
   and trajectory (i.e., navigation path) to the vehicular
   infrastructure (having RSUs and an MA in TCC) [ID-Vehicular-MM].
   This vehicular infrastructure can predict the future positions of the
   vehicles with their mobility information (i.e., the current position,
   speed, direction, and trajectory) for the efficient mobility
   management (e.g., proactive handover).  For a better proactive
   handover, link-layer parameters, such as the signal strength of a
   link-layer frame (e.g., Received Channel Power Indicator (RCPI)
   [VIP-WAVE]), can be used to determine the moment of a handover
   between RSUs along with mobility information.

   By predicting a vehicle's mobility, the vehicular infrastructure can
   better support RSUs to perform efficient DAD, data packet routing,
   horizontal handover (i.e., handover in wireless links using a
   homogeneous radio technology), and vertical handover (i.e., handover
   in wireless links using heterogeneous radio technologies) in advance
   along with the movement of the vehicle [ID-Vehicular-MM].  For
   example, when a vehicle is moving into the wireless link under
   another RSU belonging to a different subnet, the RSU can proactively
   perform the DAD for the sake of the vehicle, reducing IPv6 control
   traffic overhead in the wireless link.  To prevent a hacker from
   impersonating RSUs as bogus RSUs, RSUs and MA in the vehicular
   infrastructure need to have secure channels via IPsec.

   Therefore, with a proactive handover and a multihop DAD in vehicular
   networks, RSUs needs to efficiently forward data packets from the
   wired network (or the wireless network) to a moving destination
   vehicle along its trajectory.






Jeong, Ed.                Expires April 5, 2020                [Page 19]


Internet-Draft          IPWAVE Problem Statement            October 2019


6.  Security Considerations

   This section discusses security and privacy for IP-based vehicular
   networking.  The security and privacy are one of key components in
   IP-based vehicular networking, such as neighbor discovery and
   mobility management, so they need to be analyzed in depth.

   Strong security measures shall protect vehicles roaming in road
   networks from the attacks of malicious nodes, which are controlled by
   hackers.  For safety applications, the cooperation among vehicles is
   assumed.  Malicious nodes may disseminate wrong driving information
   (e.g., location, speed, and direction) to make driving be unsafe.
   Sybil attack, which tries to confuse a vehicle with multiple false
   identities, disturbs a vehicle in taking a safe maneuver.  This sybil
   attack should be prevented through the cooperation between good
   vehicles and RSUs.  Note that good vehicles are ones with valid
   certificates that are determined by the authentication process with
   an authentication server in the vehicular network.  Applications on
   IP-based vehicular networking, which are resilient to such a sybil
   attack, are not developed and tested yet.

   Security and privacy are paramount in the V2I, V2V, and V2X
   networking in vehicular networks.  Only authorized vehicles should be
   allowed to use vehicular networking.  Also, in-vehicle devices and
   mobile devices in a vehicle need to communicate with other in-vehicle
   devices and mobile devices in another vehicle, and other servers in
   an RSU in a secure way.  Even a perfectly authorized and legitimate
   vehicle may be hacked to run malicious applications to track and
   collect other vehicles' information.  For this case, an attack
   mitigation process may be required to reduce the aftermath of the
   malicious behaviors.

   A Vehicle Identification Number (VIN) and a user certificate along
   with in-vehicle device's identifier generation can be used to
   efficiently authenticate a vehicle or a user through a road
   infrastructure node (e.g., RSU) connected to an authentication server
   in TCC.  Also, Transport Layer Security (TLS) certificates can be
   used for secure E2E vehicle communications.

   For secure V2I communication, a secure channel between a mobile
   router in a vehicle and a fixed router in an RSU should be
   established, as shown in Figure 2.  Also, for secure V2V
   communication, a secure channel between a mobile router in a vehicle
   and a mobile router in another vehicle should be established, as
   shown in Figure 3.

   To prevent an adversary from tracking a vehicle with its MAC address
   or IPv6 address, MAC address pseudonym should be provided to the



Jeong, Ed.                Expires April 5, 2020                [Page 20]


Internet-Draft          IPWAVE Problem Statement            October 2019


   vehicle; that is, each vehicle should periodically update its MAC
   address and the corresponding IPv6 address as suggested in
   [RFC4086][RFC4941].  Such an update of the MAC and IPv6 addresses
   should not interrupt the E2E communications between two vehicles (or
   between a vehicle and an RSU) in terms of transport layer for a long-
   living higher-layer session.  However, if this pseudonym is performed
   without strong E2E confidentiality, there will be no privacy benefit
   from changing MAC and IP addresses, because an adversary can see the
   change of the MAC and IP addresses and track the vehicle with those
   addresses.

   For the IPv6 ND, the vehicular-network-wide DAD is required for the
   uniqueness of the IPv6 address of a vehicle's wireless interface.
   This DAD can be used as a flooding attack that makes the DAD-related
   ND packets are disseminated over the VANET and vehicular network
   including the RSUs and the MA.  The vehicles and RSUs need to filter
   out suspicious ND traffic in advance.

   For the mobility management, a malicious vehicle can construct
   multiple virtual bogus vehicles, and register them with the RSU and
   the MA.  This registration makes the RSU and MA waste their
   resources.  The RSU and MA need to determine whether a vehicle is
   genuine or bogus in the mobility management.

7.  Informative References

   [Automotive-Sensing]
              Choi, J., Va, V., Gonzalez-Prelcic, N., Daniels, R., R.
              Bhat, C., and R. W. Heath, "Millimeter-Wave Vehicular
              Communication to Support Massive Automotive Sensing",
              IEEE Communications Magazine, December 2016.

   [CA-Cruise-Control]
              California Partners for Advanced Transportation Technology
              (PATH), "Cooperative Adaptive Cruise Control", [Online]
              Available:
              http://www.path.berkeley.edu/research/automated-and-
              connected-vehicles/cooperative-adaptive-cruise-control,
              2017.

   [CASD]     Shen, Y., Jeong, J., Oh, T., and S. Son, "CASD: A
              Framework of Context-Awareness Safety Driving in Vehicular
              Networks", International Workshop on Device Centric Cloud
              (DC2), March 2016.







Jeong, Ed.                Expires April 5, 2020                [Page 21]


Internet-Draft          IPWAVE Problem Statement            October 2019


   [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.

   [FirstNet]
              U.S. National Telecommunications and Information
              Administration (NTIA), "First Responder Network Authority
              (FirstNet)", [Online]
              Available: https://www.firstnet.gov/, 2012.

   [FirstNet-Report]
              First Responder Network Authority, "FY 2017: ANNUAL REPORT
              TO CONGRESS, Advancing Public Safety Broadband
              Communications", FirstNet FY 2017, December 2017.

   [Fuel-Efficient]
              van de Hoef, S., H. Johansson, K., and D. V. Dimarogonas,
              "Fuel-Efficient En Route Formation of Truck Platoons",
              IEEE Transactions on Intelligent Transportation Systems,
              January 2018.

   [ID-Multicast-Problems]
              Perkins, C., McBride, M., Stanley, D., Kumari, W., and JC.
              Zuniga, "Multicast Considerations over IEEE 802 Wireless
              Media", draft-ietf-mboned-ieee802-mcast-problems-06 (work
              in progress), July 2019.

   [ID-Vehicular-MM]
              Jeong, J., Ed., Shen, Y., and Z. Xiang, "Vehicular
              Mobility Management for IP-Based Vehicular Networks",
              draft-jeong-ipwave-vehicular-mobility-management-01 (work
              in progress), July 2019.

   [ID-Vehicular-ND]
              Jeong, J., Ed., Shen, Y., and Z. Xiang, "Vehicular
              Neighbor Discovery for IP-Based Vehicular Networks",
              draft-jeong-ipwave-vehicular-neighbor-discovery-07 (work
              in progress), July 2019.



Jeong, Ed.                Expires April 5, 2020                [Page 22]


Internet-Draft          IPWAVE Problem Statement            October 2019


   [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.

   [IEEE-802.11-OCB]
              "Part 11: Wireless LAN Medium Access Control (MAC) and
              Physical Layer (PHY) Specifications", IEEE Std
              802.11-2016, December 2016.

   [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.

   [Intro-to-Algorithms]
              H. Cormen, T., E. Leiserson, C., L. Rivest, R., and C.
              Stein, "Introduction to Algorithms, 3rd ed.", The
              MIT Press, July 2009.

   [IPv6-over-802.11-OCB]
              Benamar, N., Haerri, J., Lee, J., and T. Ernst, "Basic
              Support for IPv6 over IEEE Std 802.11 Networks Operating
              Outside the Context of a Basic Service Set (IPv6-over-
              80211-OCB)", draft-ietf-ipwave-ipv6-over-80211ocb-49 (work
              in progress), July 2019.

   [ISO-ITS-IPv6]
              ISO/TC 204, "Intelligent Transport Systems -
              Communications Access for Land Mobiles (CALM) - IPv6
              Networking", ISO 21210:2012, June 2012.

   [NHTSA-ACAS-Report]
              National Highway Traffic Safety Administration (NHTSA),
              "Final Report of Automotive Collision Avoidance Systems
              (ACAS) Program", DOT HS 809 080, August 2000.

   [RFC3561]  Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On-
              Demand Distance Vector (AODV) Routing", RFC 3561, July
              2003.

   [RFC3849]  Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
              Reserved for Documentation", RFC 3849, July 2004.






Jeong, Ed.                Expires April 5, 2020                [Page 23]


Internet-Draft          IPWAVE Problem Statement            October 2019


   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", RFC 4086, June
              2005.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP Version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862, September 2007.

   [RFC4941]  Narten, T., Draves, R., and S. Krishnan, "Privacy
              Extensions for Stateless Address Autoconfiguration in
              IPv6", RFC 4941, September 2007.

   [RFC5213]  Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
              Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
              RFC 5213, August 2008.

   [RFC5844]  Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
              Mobile IPv6", RFC 5844, May 2010.

   [RFC5889]  Baccelli, E. and M. Townsley, "IP Addressing Model in Ad
              Hoc Networks", RFC 5889, September 2010.

   [RFC5944]  Perkins, C., Ed., "IP Mobility Support in IPv4, Revised",
              RFC 5944, November 2010.

   [RFC6250]  Thaler, D., "Evolution of the IP Model", RFC 6250, May
              2011.

   [RFC6275]  Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
              Support in IPv6", RFC 6275, July 2011.

   [RFC6775]  Shelby, Z., Chakrabarti, S., Nordmark, E., and C. Bormann,
              "Neighbor Discovery Optimization for IPv6 over Low-Power
              Wireless Personal Area Networks (6LoWPANs)", RFC 6775,
              November 2012.

   [RFC7181]  Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
              "The Optimized Link State Routing Protocol Version 2",
              RFC 7181, April 2014.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", RFC 8200, July 2017.






Jeong, Ed.                Expires April 5, 2020                [Page 24]


Internet-Draft          IPWAVE Problem Statement            October 2019


   [SAINT]    Jeong, J., Jeong, H., Lee, E., Oh, T., and D. Du, "SAINT:
              Self-Adaptive Interactive Navigation Tool for Cloud-Based
              Vehicular Traffic Optimization", IEEE Transactions on
              Vehicular Technology, Vol. 65, No. 6, June 2016.

   [SAINTplus]
              Shen, Y., Lee, J., Jeong, H., Jeong, J., Lee, E., and D.
              Du, "SAINT+: Self-Adaptive Interactive Navigation Tool+
              for Emergency Service Delivery Optimization",
              IEEE Transactions on Intelligent Transportation Systems,
              June 2017.

   [SANA]     Hwang, T. and J. Jeong, "SANA: Safety-Aware Navigation
              Application for Pedestrian Protection in Vehicular
              Networks", Springer Lecture Notes in Computer Science
              (LNCS), Vol. 9502, December 2015.

   [Scrambler-Attack]
              Bloessl, B., Sommer, C., Dressier, F., and D. Eckhoff,
              "The Scrambler Attack: A Robust Physical Layer Attack on
              Location Privacy in Vehicular Networks", IEEE 2015
              International Conference on Computing, Networking and
              Communications (ICNC), February 2015.

   [Timing-Attack]
              Matte, C., Cunche, M., Rousseau, F., and M. Vanhoef,
              "Defeating MAC Address Randomization Through Timing
              Attacks", ACM the 9th ACM Conference on Security & Privacy
              in Wireless and Mobile Networks (WiSec '16), July 2016.

   [Truck-Platooning]
              California Partners for Advanced Transportation Technology
              (PATH), "Automated Truck Platooning", [Online] Available:
              http://www.path.berkeley.edu/research/automated-and-
              connected-vehicles/truck-platooning, 2017.

   [TS-23.285-3GPP]
              3GPP, "Architecture Enhancements for V2X Services", 3GPP
              TS 23.285, June 2018.

   [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.






Jeong, Ed.                Expires April 5, 2020                [Page 25]


Internet-Draft          IPWAVE Problem Statement            October 2019


   [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.































Jeong, Ed.                Expires April 5, 2020                [Page 26]


Internet-Draft          IPWAVE Problem Statement            October 2019


Appendix A.  Changes from draft-ietf-ipwave-vehicular-networking-11

   The following changes are made from draft-ietf-ipwave-vehicular-
   networking-11:

   o  This version is revised based on the comments from Charlie Perkins
      and Sandra Cespedes.

   o  In Section 5, the problem statement is revisd with easily
      identifiable problems.

   o  In Section 1, the description of GeoNetworking (GN) protocols
      (i.e., geographic routing) is removed because the GN protocols are
      not relevant to the IPWAVE's use cases.

   o  In Section 2, the terms of OCB, Context-Awareness, Platooning, and
      Class-Based Safety Plan are clarified.

   o  In Section 2, the definition of an RSU is revised so that it can
      accommodate multiple routers (or switches) and servers (including
      DNS server and edge computing server) as an edge computing system
      because the RSU is regularly a router or switch.

   o  In Section 4.1, a general vehicular network architecture is
      proposed for the problem statement along with Figure 1.  This
      figure clarifies that a single subnet prefix can span multiple
      vehicles that construct a subnet.  Also, some components in the
      vehicular network architecture may not be needed such as Vehicular
      Cloud, Traffic Control Center, and Mobility Anchor.

   o  In Section 5.1.1, the motivation of a new link model as a
      vehicular link model is added.  The "on-link" and "off-link" for
      prefixes are classified according to the subnet topology of VANET.

   o  In Section 5.1.1, the merging and partitioning of VANETs is
      described, and the requirements of the IPv6 ND are addressed for
      the merging and partitioning as a problem statement.

   o  In Section 5.1.2, a citation of [Scrambler-Attack], which uses the
      scrambler seed in the IEEE 802.11-OCB frames as fingerprint
      information, is added to show the insufficiency of the MAC address
      pseudonym for privacy.

   o  In Section 5.1, the subsection of Prefix Dissemination/Exchange is
      removed because the Prefix Dissemination/Exchange subsection
      discusses a solution rather than a problem or requirement.





Jeong, Ed.                Expires April 5, 2020                [Page 27]


Internet-Draft          IPWAVE Problem Statement            October 2019


   o  In Section 5.1.3, the motivation of merging the IPv6 ND and a
      VANET routing protocol is explained to improve wireless channel
      utilization by removing redundant neighbor information exchange.

   o  The text of the problems and requirements of security and privacy
      in vehicular networks are moved to Section 6.

   o  In Section 6, the compromise of a perfectly authorized and
      legitimate vehicle is described as a security problem to be
      considered.

   o  In Section 3.3, the description of Vehicle-to-Pedestrian (V2P) is
      concised to deliver the clear concept of the direct communication
      between a vehicle and a pedestrian.

Appendix B.  Acknowledgments

   This work was supported by Basic Science Research Program through the
   National Research Foundation of Korea (NRF) funded by the Ministry of
   Education (2017R1D1A1B03035885).

   This work was supported in part by the MSIT (Ministry of Science and
   ICT), Korea, under the ITRC (Information Technology Research Center)
   support program (IITP-2019-2017-0-01633) supervised by the IITP
   (Institute for Information & communications Technology Promotion).

   This work was supported in part by the French research project
   DataTweet (ANR-13-INFR-0008) and in part by the HIGHTS project funded
   by the European Commission I (636537-H2020).

Appendix C.  Contributors

   This document is a group work of IPWAVE working group, greatly
   benefiting from inputs and texts by Rex Buddenberg (Naval
   Postgraduate School), Thierry Ernst (YoGoKo), Bokor Laszlo (Budapest
   University of Technology and Economics), Jose Santa Lozanoi
   (Universidad of Murcia), Richard Roy (MIT), Francois Simon (Pilot),
   Sri Gundavelli (Cisco), Erik Nordmark, Dirk von Hugo (Deutsche
   Telekom), and Pascal Thubert (Cisco).  The authors sincerely
   appreciate 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



Jeong, Ed.                Expires April 5, 2020                [Page 28]


Internet-Draft          IPWAVE Problem Statement            October 2019


   Phone: +212 6 70 83 22 36
   EMail: benamar73@gmail.com


   Sandra Cespedes
   NIC Chile Research Labs
   Universidad de Chile
   Av.  Blanco Encalada 1975
   Santiago
   Chile


   Phone: +56 2 29784093
   EMail: scespede@niclabs.cl


   Jerome Haerri
   Communication Systems Department
   EURECOM
   Sophia-Antipolis
   France

   Phone: +33 4 93 00 81 34
   EMail: jerome.haerri@eurecom.fr


   Dapeng Liu
   Alibaba
   Beijing, Beijing 100022
   China

   Phone: +86 13911788933
   EMail: max.ldp@alibaba-inc.com


   Tae (Tom) Oh
   Department of Information Sciences and Technologies
   Rochester Institute of Technology
   One Lomb Memorial Drive
   Rochester, NY 14623-5603
   USA

   Phone: +1 585 475 7642
   EMail: Tom.Oh@rit.edu


   Charles E.  Perkins
   Futurewei Inc.



Jeong, Ed.                Expires April 5, 2020                [Page 29]


Internet-Draft          IPWAVE Problem Statement            October 2019


   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

   Phone: +33169089223
   EMail: Alexandre.Petrescu@cea.fr


   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
   Fax: +82 31 290 7996
   EMail: chrisshen@skku.edu
   URI: http://iotlab.skku.edu/people-chris-shen.php


   Michelle Wetterwald
   FBConsulting
   21, Route de Luxembourg
   Wasserbillig, Luxembourg L-6633
   Luxembourg

   EMail: Michelle.Wetterwald@gmail.com


Author's Address










Jeong, Ed.                Expires April 5, 2020                [Page 30]


Internet-Draft          IPWAVE Problem Statement            October 2019


   Jaehoon Paul Jeong (editor)
   Department of Computer Science and Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon, Gyeonggi-Do  16419
   Republic of Korea

   Phone: +82 31 299 4957
   Fax:   +82 31 290 7996
   EMail: pauljeong@skku.edu
   URI:   http://iotlab.skku.edu/people-jaehoon-jeong.php








































Jeong, Ed.                Expires April 5, 2020                [Page 31]