Vehicles that talk. Infrastructure that answers. Messages you can prove.
V2X is the layer that tells a vehicle what its own sensors cannot see: the car braking hard four vehicles ahead, the truck approaching the blind intersection behind a building, the signal that turns red in 2.4 seconds. It works through fog, around corners and in the dark, because it is radio rather than optics. And every one of those messages is only useful if the receiver can prove, in a few milliseconds and without a network, that it came from a device that was allowed to send it.
That proof is a hardware problem before it is a cryptography problem. This site covers both — the technology and the trust layer underneath it — and Ambimat Electronics builds the hardware that implements them.
Start here. No background assumed.
V2X stands for vehicle-to-everything. Equipped vehicles broadcast a short message about ten times a second — here I am, this is my speed and direction, I have just braked hard — and every other equipped vehicle nearby hears it. Traffic signals broadcast too. So do roadworks and emergency vehicles.
Radio reaches where eyes and cameras cannot: around the corner, through fog, behind a truck, over a hill. A vehicle can be warned about something it has no way of seeing yet.
What V2X is
The plain-English explanation, then the precise one.
How it works
The six steps, a worked example at a blind intersection, and what is actually in the car.
What it is for
Three benefits, not one — safety, traffic efficiency and emissions — with the measured evidence for each.
What C-V2X means
The radio technology carrying almost all of it, and why every regulator since 2018 has chosen it.
Glossary
Every acronym on this site, defined.
Frequently asked
Ninety question-shaped answers, grouped by theme, each linking to the page that treats it in full.
The technology argument is settled. The deployment argument is not.
Every jurisdiction that has chosen a V2X radio technology since 2018 — the United States, China, South Korea, Japan and India — has chosen C-V2X. The European Union alone remains formally technology-neutral, and has the largest deployed fleet in the world running on the other one. What no two jurisdictions agree on is whether anyone has to fit it.
| Jurisdiction | Where it stands, August 2026 |
|---|---|
| United States | C-V2X only, 30 MHz. DSRC ceases 14 December 2026. No fitment mandate — the proposed V2V rule was withdrawn in 2023, and no automaker currently ships V2X in a US production vehicle. |
| European Union | Technology neutral, 60 MHz, the most mature multi-root trust architecture anywhere. No fitment mandate — but over two million Volkswagens shipped with it anyway, and 6,000+ roadside units across 30% of the TEN-T network. |
| China | LTE-V2X only, 20 MHz, twenty pilot cities, 11,000+ roadside units, and around 4% vehicle penetration. The clearest evidence anywhere that building the infrastructure first does not pull fitment. |
| India | A draft mandate for every new vehicle from October 2028, including motorcycles and scooters. If finalised, the first of its kind in the world. |
Three instruments in ninety-five days, and a mandate nobody else has attempted.
- 30 April 2026 — TRAI publishes Consultation Paper No. 08/2026 on a regulatory framework for V2X communication.
- 10 June 2026 — DoT notifies G.S.R. 466(E), exempting C-V2X on-board units in 5875–5905 MHz from licensing.
- 3 August 2026 — MoRTH publishes a draft amendment to the Central Motor Vehicles Rules, 1989, proposing that every newly manufactured L, M and N category vehicle carry a factory-fitted, AIS-230-compliant C-V2X on-board unit from 1 October 2028.
India sells roughly nineteen to twenty million two-wheelers a year. A mandate that covers them is a larger single addition to the global V2X fleet than everything deployed everywhere else combined — and it is the first real test of whether regulation can break the fitment deadlock that has stalled V2X in every other market.
We cover it in more depth than anyone else because we are in it. India's V2X regulation, in detail →
Six things, and they are meant to be read in any order.
The fundamentals
What V2X is, how it works step by step, and what V2V, V2I, V2N, V2P and the rest actually mean — with the real message names, not the marketing ones.
The technology
C-V2X, PC5 and Uu, the 3GPP releases, 5.9 GHz spectrum, the message sets, and the silicon that runs them.
The security
Why an unsigned V2X message is worthless, how V2X PKI differs from web PKI, and why the keys have to be in hardware.
The regulation
The US, the EU, China, Japan, Korea and India — what each has decided, and what each has not.
The market
Who ships V2X today, who has walked away from it, and the argument between cooperative and autonomous perception.
Developer resources
Standards, stacks, open source, test infrastructure, and browser-based tools that parse real certificates.
Forty-four years of embedded hardware, and a secure element already shipping.
Ambimat Electronics is an Indian design and manufacturing house, established 1982, serving ISRO, BARC and the Indian Army among others. The V2X programme is not a pivot; it is four existing capabilities pointed at one problem.
| Existing capability | What it becomes in V2X | Status |
|---|---|---|
| AmbiLogistics — deployed vehicle tracking hardware with GPS, IMU and cellular, validated on Indian roads | The mechanical, thermal and radio baseline for AmbiOBU | Development platform |
| AmbiSpace / AmbiDefence — ruggedised outdoor electronics, IP-rated enclosures, thermal and vibration tolerance | The baseline for AmbiRSU | Development platform |
| AmbiSecure — Common Criteria EAL6+ compliant secure elements, JavaCard applets, HSM-backed personalisation, shipping since 2017 | AmbiSEC, the hardware root of trust for both | Shipping |
| Firmware, secure boot and encrypted OTA pipelines for deployed IoT fleets | AmbiOTA | Shipping |
On the two development platforms, plainly: AmbiOBU and AmbiRSU are not products you can order. The hardware baselines exist and have been in the field for years in another form. What they need to become finished products is a partner with a deployment — an OEM with a fitment deadline, a road authority with a corridor, a tier-1 with an integration programme. If that is you, we would like to talk.
The product line → · AmbiSecure, the security business unit →
What we are, and what we are not.
Ambimat supplies hardware and the hardware-rooted identity layer. It does not operate a national trust anchor, and it does not sell a certified automotive software stack.
- Ambimat is not a V2X Root CA operator. That is a national trust-anchor function for a designated authority.
- Ambimat does not currently ship an ISO 26262 or Automotive SPICE certified V2X stack. Automotive certification of the integrated module is a target, not a claim.
- AmbiOBU and AmbiRSU are development platforms open to collaboration, not products in production deployment.
- Standards named on this site in relation to our own products describe what the hardware is built to comply with. They are design and compliance references, not assertions that any particular product carries a formal certificate.
- References to TRAI, MoRTH, DoT, TEC, CCA or C-DOT documents are references to public documents. Nothing on this site implies endorsement, procurement or any other relationship.
Where to go next.
What is V2X
The sensor problem, the information problem, and the modes.
How V2X works
Six steps from a vehicle sensing its own state to a driver being warned.
C-V2X
PC5, Uu, and Release 14 through Release 19.
V2X security
Offline trust decisions made in milliseconds, thousands of times a second.
India regulation
TRAI, DoT and MoRTH, in the order they moved.
Developer resources
Standards, stacks, test infrastructure and certificate tools.
Designing a V2X OBU, RSU or PKI integration?
We will walk the trust model end to end with your hardware lead and your security architect — secure-element selection, applet structure, provisioning-line architecture, EA/AA integration patterns. Reference designs under NDA.
Questions this page answers.
What does V2X stand for?
Vehicle-to-Everything. It is the umbrella term for a vehicle exchanging structured, standardised messages with other vehicles (V2V), roadside infrastructure (V2I), the cellular network (V2N), pedestrians and other vulnerable road users (V2P), and — in the energy sense, over the charging cable rather than the radio — the grid, a home or a load (V2G, V2H, V2L).
Is V2X the same as C-V2X?
No. V2X is the application: what the vehicle communicates and why. C-V2X is one of the two radio technologies that carries it, defined by 3GPP and based on cellular technology. The other is DSRC, based on IEEE 802.11p and known in Europe as ITS-G5. Every jurisdiction that has made a technology decision since 2018 — the US, China, South Korea, Japan and India — has chosen C-V2X.
Is V2X mandatory in India?
Not yet. On 3 August 2026 the Ministry of Road Transport and Highways published a draft notification proposing that all newly manufactured L, M and N category vehicles carry an AIS-230-compliant C-V2X On-Board Unit from 1 October 2028, with an earlier 1 October 2027 date for vehicles voluntarily fitted with such a system. The draft was open for comment for thirty days. Until it is finalised, nothing is mandatory.
Does V2X replace cameras, radar and lidar?
No, and no serious proposal has suggested it should. Cameras, radar and lidar are line-of-sight sensors: they cannot see through a truck, around a building or over a crest. V2X is a non-line-of-sight information source that also carries data no optical sensor can infer — brake-pedal state, ABS activation, a signal's countdown to green, a vehicle's predicted path. It is an additional input to the same perception stack.