Internet-Draft IPv6 over 5G V2X October 2023
Jeong, et al. Expires 25 April 2024 [Page]
Workgroup:
6man Working Group
Internet-Draft:
draft-jeong-6man-ipv6-over-5g-v2x-02
Published:
Intended Status:
Standards Track
Expires:
Authors:
J. Jeong, Ed.
Sungkyunkwan University
B. Mugabarigira
Sungkyunkwan University
Y. Shen
Sungkyunkwan University
A. Petrescu
Université Paris-Saclay, CEA, LIST
S. Cespedes
Universidad de Chile

Basic Support for IPv6 Networks Operating over 5G Vehicle-to-Everything Communications

Abstract

This document provides methods and settings for using IPv6 to communicate among IPv6 nodes within the communication range of one another over 5G V2X (i.e., the 5th Generation Vehicle-to-Everything) links. Support for these methods and settings require minimal changes to the existing IPv6 protocol stack. This document also describes limitations associated with using these methods. Optimizations and usage of IPv6 in more complex 5G scenarios are not covered in this specification and are a subject for future work.

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 25 April 2024.

1. Introduction

This document provides a baseline for using IPv6 in the hosts communicating with each other by the 5th Generation New Radio (NR) Vehicle-to-Everything (5G NR V2X) links [TS23303] [TS23304] defined by the 3rd Generation Partnership Project (3GPP). The baseline defined in this document has the minimal changes to existing stacks. Moreover, the document identifies the limitations of such usage.

The 3GPP has published the long-term evolution V2X (LTE V2X) in its Release 14 to support V2X communications using the Uu and PC5 reference points for vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V), respectively. In the recent development, the 5G V2X has also been proposed to enhance the existing and future V2X use cases. Particularly, the 5G V2X improves the sidelink resource allocation and the handling of quality-of-service (QoS) in the current 5G networks, and beyond 5G networks, such as 6G networks. It also extends the communication modes for UE over PC5 from broadcast mode to groupcast and unicast mode [TS24587].

The motivation for this document is the service discovery that utilizes the specifications developed by 3GPP to enhance and broaden the connectivity in a vehicular environment. As the 5G Core (5GC) and 5G New Radio (5G-NR) with 5G User Equipment (UE) are being deployed world wide, they can be of great importance in creating a connected network for moving objects such as automobiles, motorcycles, drones etc.

However, for IPv6-based 5G V2X communications based on the 3GPP documents [TS23287] [TS24587] it is still not clear how the IPv6 addresses are well configured for multi-hop 5G V2X networks. Particularly, when the Stateless Address Autoconfiguration (SLAAC) process is used in IPv6-based 5G V2X communications, a vehicle as an IPv6 router, which assigns an IPv6 prefix to another vehicle in SLAAC, shall be selected or determined. For a scenario having ground moving vehicles, how to determine the IPv6 router for SLAAC is still not clear. In addition, the 3GPP 5G V2X specifications discourage the use of the Duplicate Address Detection (DAD) [RFC4862] [RFC7527] and Neighbor Discover (ND) messages [RFC4861], which arises the concern of unusable IPv6-based 5G V2X services in the future. On top of that, other issues such as multi-hop packet forwarding among non-IPv6 router vehicles and efficiency of mobility management may also occur [RFC9365].

Thus this document offers the basic support for IPv6-based 5G V2X communications to enable application services such as infotainment and cooperative driving safety through the driving context information sharing.

                       +------------+
                       |   NG-RAN   |  Base Station
                       +------------+ (e.g., gNodeB)
                             ^
                             :
                             : Uu
                             :
                             V
+------------+   PC5   +------------+   PC5   +------------+
| IP-VehUE A |<.......>| IP-VehUE B |<.......>|    UE C    |
+------------+         +------------+         +------------+
   Car A ==>              Car B ==>           Pedestrian ==>

      <....> Wireless Link   ===> Moving Direction
Figure 1: 3GPP 5G V2X Architecture

2. Terminology

This document uses the terminology described in [RFC8691]. In addition, the following terms are defined below:

  • IP-VehUE (Internet Protocol Vehicle User Equipment): It is a UE device mounted on a vehicle such as car, motorcycle, and scooter that operates based on 5G V2X services to transmit IPv6 data packets. It can connect to the vehicle's internal networks.

  • NG-RAN (Next Generation Radio Access Network) node: It is a base station node that provides user plane and control plane functions toward IP-VehUEs, and it also connects to 5GC networks. It can be a gNodeB (gNB) in 5G or an ng-eNobdB (ng-eNB) in E-UTRA per the 5G network definition [TS23501] [TS38300].

  • 5G NR-PC5 RP (5G New Radio PC5 Reference Point): The 5G NR-PC5 RP is referred to as communication links among IP-VehUEs (i.e., V2V).

  • 5G NR-Uu RP(5G New Radio Uu Reference Point): The 5G NR-Uu RP is referred to as communication links between an IP-VehUE and an NG-RAN node.

3. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

4. Overview of 5G V2X Communications

  +-------------------+
  |  UDP/TCP V2X App  |
  +-------------------+
            |
  +===================+
  |       IPv6        |
  +===================+
            |
+-----------------------+
|3GPP Underlying Layers |
|   +--------------+    |
|   |      SDAP    |    |
|   +--------------+    |
|           |           |
|   +--------------+    |
|   |      PDCP    |    |
|   +--------------+    |
|           |           |
|   +--------------+    |
|   |      RLC     |    |
|   +--------------+    |
|           |           |
|   +--------------+    |
|   |      MAC     |    |
|   +--------------+    |
|           |           |
|   +--------------+    |
|   |      PHY     |    |
|   +--------------+    |
+-----------------------+

Figure 2: 3GPP IPv6-based 5G V2X Communications Protocol Stack

A high-level system architecture for V2X communication over PC5 and Uu reference points is shown in Figure 1. A modified sidelink interface allows IP-VehUEs to communicate with each other by the PC5 RP. An IP-VehUE can connect with a stationary NG-RAN through Uu interface. Both communications among IP-VehUEs and between IP-VehUEs and NG-RAN mainly rely on the lower layers shown in Figure 2.

The 5G V2X communications support both IP and non-IP based message exchanges in unicast, broadcast, and groupcast modes per 3GPP documents [TS23287] [TS24587]. For the IPv6-based 5G V2X communications via PC5 RP, only IPv6 is used for the communications. In the unicast mode of IPv6-based 5G V2X by PC5 RP, an IP-VehUE uses either the IPv6 Stateless Address Autoconfiguration (SLAAC) process or the IPv6 link-local addresses to generate usable IP addresses [RFC4862].

  • When using SLAAC, an IP-VehUE uses an IPv6 prefix sent by another IP-VehUE acting as an IPv6 default router.

  • When using IPv6 link-local addresses, an IP-VehUE forms the link-local addresses locally without Duplicate Address Detection (DAD) [TS23287].

In the broadcast and groupcast modes of 5G V2X over PC5 RP, an IP-VehUE configures a link-local IPv6 address as the source IP address. The configuration of the link-local IPv6 address does not send Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages for DAD per the 3GPP document [TS23287].

6. Security Considerations

The security considerations in this document inherit those in [RFC8691][RFC9365].

7. IANA Considerations

This document does not require any IANA actions.

8. References

8.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC2464]
Crawford, M., "Transmission of IPv6 Packets over Ethernet Networks", RFC 2464, DOI 10.17487/RFC2464, , <https://www.rfc-editor.org/info/rfc2464>.
[RFC4291]
Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, , <https://www.rfc-editor.org/info/rfc4291>.
[RFC4193]
Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast Addresses", RFC 4193, DOI 10.17487/RFC4193, , <https://www.rfc-editor.org/info/rfc4193>.
[RFC4861]
Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, , <https://www.rfc-editor.org/info/rfc4861>.
[RFC4862]
Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, DOI 10.17487/RFC4862, , <https://www.rfc-editor.org/info/rfc4862>.
[RFC7527]
Asati, R., Singh, H., Beebee, W., Pignataro, C., Dart, E., and W. George, "Enhanced Duplicate Address Detection", RFC 7527, DOI 10.17487/RFC7527, , <https://www.rfc-editor.org/info/rfc7527>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[RFC8200]
Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, , <https://www.rfc-editor.org/info/rfc8200>.
[RFC8691]
Benamar, N., Härri, J., Lee, J., and T. Ernst, "Basic Support for IPv6 Networks Operating Outside the Context of a Basic Service Set over IEEE Std 802.11", RFC 8691, DOI 10.17487/RFC8691, , <https://www.rfc-editor.org/info/rfc8691>.
[RFC9365]
Jeong, J., Ed., "IPv6 Wireless Access in Vehicular Environments (IPWAVE): Problem Statement and Use Cases", RFC 9365, DOI 10.17487/RFC9365, , <https://www.rfc-editor.org/info/rfc9365>.

8.2. Informative References

[TS23287]
3GPP, "Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services", TS 23.287 V17.5.0, , <https://www.3gpp.org/DynaReport/23287.htm>.
[TS23303]
3GPP, "Proximity-based services (ProSe); Stage 2", TS 23.303 V17.0.0, , <https://www.3gpp.org/DynaReport/23303.htm>.
[TS23304]
3GPP, "Proximity based Services (ProSe) in the 5G System (5GS)", TS 23.304 V17.5.0, , <https://www.3gpp.org/DynaReport/23304.htm>.
[TS23501]
3GPP, "System Architecture for the 5G System (5GS); Stage 2", TS 23.501 V17.7.0, , <https://www.3gpp.org/DynaReport/23501.htm>.
[TS24587]
3GPP, "Vehicle-to-Everything (V2X) services in 5G System (5GS); Stage 3", TS 24.587 V18.0.0, , <https://www.3gpp.org/DynaReport/24587.htm>.
[TS38300]
3GPP, "NR; NR and NG-RAN Overall description; Stage 2", TS 38.300 V17.3.0, , <https://www.3gpp.org/DynaReport/38300.htm>.
[I-D.jeong-ipwave-vehicular-neighbor-discovery]
Jeong, J. P., Shen, Y., and S. Cespedes, "Vehicular Neighbor Discovery for IP-Based Vehicular Networks", Work in Progress, Internet-Draft, draft-jeong-ipwave-vehicular-neighbor-discovery-16, , <https://datatracker.ietf.org/doc/html/draft-jeong-ipwave-vehicular-neighbor-discovery-16>.
[I-D.jeong-ipwave-vehicular-mobility-management]
Jeong, J. P., Mugabarigira, B. A., and Y. Shen, "Vehicular Mobility Management for IP-Based Vehicular Networks", Work in Progress, Internet-Draft, draft-jeong-ipwave-vehicular-mobility-management-10, , <https://datatracker.ietf.org/doc/html/draft-jeong-ipwave-vehicular-mobility-management-10>.

Appendix A. Acknowledgments

This work was supported in part by Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korea Ministry of Science and ICT (MSIT)(No. 2022-0-01015, Development of Candidate Element Technology for Intelligent 6G Mobile Core Network).

This work was supported in part by Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korea Ministry of Science and ICT (MSIT) (No. 2022-0-01199, Regional strategic industry convergence security core talent training business).

Appendix B. Contributors

This document is a group work, greatly benefiting from inputs and texts by Erik Kline (Aalyria) and Eric Vyncke (Cisco). The authors sincerely appreciate their contributions.

The following are coauthors of this document:

Hyeongah Jung
Department of Computer Science & Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Junhee Kwon
Department of Computer Science & Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Tae (Tom) Oh
Golisano College of Computing and Information Sciences
Rochester Institute of Technology
One Lomb Memorial Drive
Rochester, NY 14623-5603
United States of America

Appendix C. Changes from draft-jeong-6man-ipv6-over-5g-v2x-01

The following changes are made from draft-jeong-6man-ipv6-over-5g-v2x-01:

  • In Section 5.4, the considerations for IPv6 SLAAC over 5G V2X are discussed.

  • There are updates in the References.

Authors' Addresses

Jaehoon Paul Jeong (editor)
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Bien Aime Mugabarigira
Department of Electical and Computer Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Yiwen Shen
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon
Gyeonggi-Do
16419
Republic of Korea
Alexandre Petrescu
Université Paris-Saclay, CEA, LIST
CEA Saclay
Gif-sur-Yvette, Ile-de-France
91190 Paris
France
Phone: +33 169089223
Sandra Cespedes
Universidad de Chile
Av. Tupper 2007
8370451 Santiago
Chile