C-ITS: Three observations on LTE-V2X and ETSI ITS-G5 – A comparison

March 21, 2018

Technical paper from NXP:

https://www.nxp.com/docs/en/white-paper/CITSCOMPWP.pdf

Abstract
In this document, we detail three observations on LTE-V2X, a proposed vehicle-to-vehicle
communication technology positioned to compete with the ETSI ITS-G5 / IEEE802.11p
communication standard.
1. Readiness:
it is stated by a group of stakeholders that the first LTE-V2X release is
‘ready’. However, all that has happened is that a first version of the 3GPP LTE standard
incorporating LTE-V2X was published by 3GPP in 2017 (LTE Release 14, in short Rel-14).
Since the first chipset will only be available at the end of 2018, widescale field-testing can
only start from 2019. Already, several flaws have been detected in the Rel-14 specification,
which will be addressed in the upcoming Rel-15.
2. Compatibility:
the LTE-V2X stakeholders suggest that LTE-V2X has a roadmap for
future development. However, future releases beyond Rel-14 (starting with Rel-15) will
not be backwards compatible to Rel-14 hardware and applications. Therefore, basic
safety messages will either only be broadcasted via Rel-14, thus disabling the potential
advantages of further technology development, or vehicles equipped with Rel-14 cellular-
based V2X technology will not be able to talk to vehicles with Rel-15 or subsequent
releases. Either way, Rel-14 will be obsolete before it is even deployed.
3. Range:
in some publications on LTE-V2X, it is stated that the range of LTE-V2X is superior
to ETSI ITS-G5 / IEEE802.11p. Range of the current ITS-G5 implementation has been
measured in real-life deployments and the results clearly show that ITS-G5 outperforms the
claimed range of the simulated LTE-V2X solutions
In conclusion, it can be stated that the current LTE-V2X is a significant step back in
performance compared to ETSI ITS-G5, and maturity and testing levels of LTE-V2X are still
very low. The standard has known problems and the claimed range advantage does not
materialize. The currently available flawed version will create the reference for all future
deployments; no progress will be possible for future LTE-V2X safety critical ITS applications.