Re: [ipwave] LTE-V2X term in Problem Statement document

[<[e-mail]>]

Hi Alex,
I strongly agree with you that we need a precise definition on what we mean with cellular V2X (often denoted as C-V2X in general – so covering LTE and 5G/NR) – especially since – as you correctly pointed out - 3GPP has none such official definition as LTE-V2X or NR-V2X .

However when defining LTE-V2X we should be aware that there are two different modes of operation for V2X communication in 3GPP cellular systems (as also described in Annex A.5 of PS document https://tools.ietf.org/html/draft-ietf-ipwave-vehicular-networking-08).

E.g. according to 3GPP TR 21.914 giving a Release 14 (i.e. LTE) Description and Summary of Rel-14 Work Items, but similarly also for 5G/NR or Rel. 15 and higher (here in still draft TR 21.915) the modes of operation are described as

-          Direct V2X communication between UEs over a 3GPP sidelink (PC5 interface)

-          V2X communication over LTE-Uu interface (i.e. via base stations / eNBs)

In addition there are 2 different modes for PC5/sidelink:

-          in coverage of cellular system with LTE assistance

-          out of coverage: ad-hoc mode w/o assistance … very similar to OCB.

So I would recommend to specify more exactly what we have in mind.

LTE-V2X: the transmission of ETSI CAM and DENM messages over IP over a cellular link such as 3GPP 4G – both via base station and directly between vehicles

Or more general:

C-V2X: the transmission of ETSI CAM and DENM messages over IP over a cellular link such as 3G, 4G and successors – both in infrastructure mode (via base station / Uu interface) and ad-hoc mode (direct link / sidelink interface) if available [since sidelink is only specified for 4G/5G]

Or one may even reflect differentiation between those modes in the acronym (which I would not recommend here being not in scope for this document)

Just my 2 cents
Kind regards
Dirk

From: its <[e-mail]> On Behalf Of Alexandre Petrescu
Sent: Mittwoch, 17. April 2019 13:18
To: [e-mail]
Subject: [ipwave] LTE-V2X term in Problem Statement document


Hi IPWAVErs,

The IPWAVE Problem Statement document uses the term 'LTE-V2X' at one point. ("e.g., IEEE 802.11-OCB and LTE-V2X")

I would like to suggest to make a careful definition of the term 'LTE-V2X'.

One would expect the term 'LTE-V2X' to be defined precisely at 3GPP or similar.  But that is not the case.  The 3GPP document that is closest to this term is RP-161298, publicly available, defines the term 'LTE_V2X' (remark underscore '_', instead of dash '-').

I suggest the addition of the following term in the Problem Statement draft:

LTE-V2X: the transmission of ETSI CAM and DENM messages over IP over a cellular link such as 3G, 4G and successors.

Alex