Toyota has had enough of this industry foot-dragging and stalling, and has thrown considerable shade at its peers – declaring that it will not be deploying V2X technologies in the US in 2021, as was previously the plan as had been announced in April last year. It attributes the decision to a need for greater industry commitment, and for the US government to preserve the 5.9 GHz DSRC spectrum.
Those in the cellular camp of the ongoing V2X dispute will probably be smirking, as this seems like a response to the mounting pressure on DSRC and the 802.11p approach in the US. However, across the pond, the C-V2X technologies appear to have been given a bloody nose, as the European Parliament sided with the European Commission’s decision to exclude cellular technologies from its V2X decision.
The European decision was made on the basis that V2X is needed now and WiFi is more mature than C-V2X and 5G. The cellular community’s counter argument is that the ITS-G5 spec is already outdated, and that this decision would set Europe back years. The decision itself was a bit of a surprise, as it looked like the parliament would be going against the commission’s recommendation, but this is not yet a final decision and so things could still change.
We mostly agreed with the initial parliamentary Transport Committee’s decision to reject the commission’s proposal, with some caveats, and with the GSMA’s complaints that the wording of the legislation – which prohibited C-V2X from being added to the ITS-G5 spec because it is not backwards compatible with WiFi, comparable to demanding that DVDs work in VHS players.
Had Toyota’s decision come after Europe had supported C-V2X, we might be able to nail 802.11p’s coffin shut. As that has not happened, the protocol lives on, even though it is getting on for being ten years old already and still not deployed in a commercial car design. It has been used in things like truck platooning, but the kingmakers here seem most likely to be the largest automakers – who would prefer one global design that they could put into every one of their designs, and certainly are averse to accommodating two distinct approaches.
So, Toyota was likely trying to force the rest of the industry’s hand, when it nailed it colors to the mast and said DSRC (using 802.11p) was the way forward. As the then-largest automaker, it probably hoped its gravitational pull was enough to bring others into the fold, and it seemed that the US government was close to mandating DSRC in new cars – something the politicians had been floating for the past two years.
However, no such law was passed, and so the cellular community was able to catch up. The FCC has also been making noises about removing its protections for the 5.9 GHz band that is currently allocated to DSRC use, on the basis that it could be better used in the 5.8 GHz WiFi band, and that (rightly so) it has received so little use.
This then led to Ford becoming the first automaker (as far as we can tell) to publicly commit to C-V2X, at CES 2019, with a plan to launch its first such vehicles in 2022. This had Qualcomm, perhaps the main proponent of C-V2X, positively gushing, and the semiconductor specialist has been advocating for the adoption of the technology with great vigor.
Currently, Toyota’s position is that the DSRC approach is superior to C-V2X. “Toyota continues to carefully monitor and evaluate developed and emerging technologies, but has concluded that Cellular V2X technologies are still in an early development phase,” said Toyota spokesman Nathan Kokes. “We remain strong supporters of DSRC technology because we believe it is the only proven and available technology for collision avoidance communication, and the only technology capable of garnering a wide industry consensus.”
Complicating the discussion is the plethora of terminologies in play. Broadly, 802.11p is a WiFi variant that was first designed in 2010, after the IEEE 802.11p Task Group was formed way back in November 2004. DSRC (Dedicated Short-Range Communication) is a US Department of Transport project focused on using the 75MHz of 5.9 GHz spectrum that the FCC designated for automotive applications in 1999. DSRC opted for 802.11p as the basis for its work. In Europe, ETSI had allocated 30 MHz of 5.9 GHz spectrum, and in a similar manner, the ITS working group in ETSI opted for 802.11p as its foundation for ITS-G5.
The other side of the coin is cellular, and boy is Qualcomm worked up about this. Essentially, C-V2X uses LTE and eventually 5G technologies as the communication basis, in the same way that 802.11p is using the WiFi stack. C-V2X stems from the 3GPP’s standards work in Release 14, with the LTE Direct feature being optimized for automotive applications. C-V2X is also sometimes referred to as Sidelink and PC5, so keep an eye out for that.
Both approaches support direct V2V connections, for things like emergency braking, as well as networked connections, where cars could be connected via an actual network – be it a specially constructed 802.11p one, or a local LTE network. C-V2X does have an advantage in Vehicle-to-Pedestrian applications, which mostly revolve around preventing cars from hitting reprobates that walk out into the road without looking for oncoming vehicles.
In terms of frequency, it seems that 802.11p would work in the 5.8 GHz ISM bands, as well as its 5.9 GHz channels. C-V2X could work here too, or in much of the other licensed spectrum available, however, there’s a huge variance in the channels available, which could see a car on a long trip having to switch from sub-GHz bands to 5.8 GHz or even higher in the 5G ecosystem. It is not clear how the car connectivity options are going to handle that.
Toyota and Volkswagen, who both take turns trading the title of largest automaker in the world, are 802.11p proponents, with Renault also publicly committed. They could have the collective clout needed to force 802.11p into commercial reality, but then we arrive at a situation where half the cars on the road speak one language, and the other half can’t understand them. That’s an outcome that nobody wants, but as we see in many areas of the IoT, is certainly a distinct possibility.
On the other side, BMW, Daimler, Ford, and the PSA Group are public automaker supporters for C-V2X, as well as the bulk of the cellular community – including Qualcomm, Intel, Huawei, Samsung, and most MNOs. Notably, Audi (part of the VW Group) and Nissan (part of the Renault-Nissan Alliance) are in the C-V2X camp and not the 802.11p one, perhaps illustrating how muddy these waters are.