Is 5G C-V2X Really Paving the Road to Autonomy?

At AutoTech Europe, TU-Automotive took a step back to look back at last year’s conference in which it was claimed that 5G C-V2X is paving the way for fully autonomous vehicles.

Key to the discussion is whether 5G as well as 5G C-V2X are sufficient for creating a fully autonomous vehicle future. Niels Peter Skov Andersen, chair of ETSI Intelligent Transport Systems Technical Committee of the European Telecommunications Standards Institute (ETSI), begins by saying V2X and C-V2X are basically the same things. ‘C-V2X’ is a term used by the telecommunications companies.

He adds: “What has to be understood is that we are operating with different forms of communication. We have short-range direct communication for communicating directly between vehicles and vehicles as well as directly between vehicles and road infrastructure. We would typically use that for tactical information, to communicate things drivers can see out of the window or around corners. It covers all of the things you need to do to avoid crashing.

“Then you have long-range communications where you can, for example, update the map which is not necessarily a fixed map but a dynamic map with roadworks and other road event updates,” he explains. C-V2X is a communications technology they propose for short and long-range communications, and he says there are more than 20.000 km of roads covered by ITS-G5 and believes it’s up to the industry to implement the standards.

ETSI standards

ETSI standards are based on ITS-G5, which he explains is a profiling of IEEE 802.11p – the Wi-Fi standard that is in all phones and laptops. They are being deployed in Europe at the moment and Volkswagen is one of the automakers involved with their deployments in conjunction with a number of road operators for common deployment profiling of the standards. He explains: “The C-V2X and ITS-G5 are the transmission layer. However, they are not compatible. For the upper layers, the applications, the ETSI standard is able to work over both of these.”

A new standard is also being developed too, which will act like a beacon signal that’s traditionally used on a plane or a ship. So, a signal could be sent out to warn other vehicles of a breakdown or an accident, or even of ice on the road. However, there is a key difference to planes in the sky. Congestion is much more significant on the ground as a result of the greater density of cars and other vehicles.

Density makes the situation more complex. Beacon signals nevertheless tell everyone else where you are and how you are moving. So, whenever an accident or breakdown occurs, and presents a danger to other road users, the road operator can use this information to take appropriate action.

Vulnerable road users

Then there is a second phase to consider, which is about vulnerable road users and permitting them to share information about themselves. “GPS or Galileo might not get sufficient location precision to know whether someone is on the pavement or in the street,” he explains before revealing there will be ‘collective perception’ later this year.

A report on the US National Library of Medicine’s website, Collective Perception: A Safety Perspective by Florian A. Schiegg et al, defines it as follows: “Collective perception allows stations (traffic participants and infrastructure) to inform connected stations of objects (such as pedestrians, obstacles, and other vehicles) detected by their object-tracking sensors.” Both vehicles and infrastructure use a number of sensors to detect other road users, such as pedestrians and share that information with others about what they see and perceive within their environment.

The aim is to increase the penetration of electronically visible traffic participants by seeing road users, whether they have a mobile phone or not. “Many traffic lights are already equipped with sensors and it’s about sharing information about us and the environment to compensate for the fact that not everybody is equipped or has mobile phones,” he explains before commenting on the third phase.

Co-operative manoeuvers

The third phase is to enable co-operative manoeuvers in traffic. So, for example, a car may need to merge into traffic from an intersection on the highway. The trouble is that adaptive cruise control’s reaction is often delayed. That’s because the onboard sensors, cameras, lidars, and radars take a moment to react to a vehicle in front that is accelerating or decelerating. This leads to a shockwave effect that makes vehicles accelerate and decelerate more than they should need to do.

The solution is to use communication to inform more quickly a vehicle ahead of it to react immediately without delay. “If you want to have an optimal flow, you need to 2.9 seconds between the cars with traditional ACC, and with co-operative ACC you need 0.9 seconds,” he explains. The shockwave effect arises because the distance between each vehicle is too small.

5G not essential

Lukas Neckermann, a global expert on mobility and co-initiator of PAVE Europe believes that 5G is very important, but not essential as it’s an enabler for automated vehicle deployment. He finds that congestion is not caused by the sheer volume of traffic but by acceleration and deceleration in traffic. This can lead to greater tailpipe emissions and poses a risk to road safety.

He believes that autonomous and connected vehicles can bring about smoother traffic flows through anticipatory and collaborative driving. He adds: “Vehicles that are able to ‘talk’ to each other have greater vision. They, effectively, can ‘see’ what a human can’t, such as over the crest of a hill, or behind a large truck. This means they have better ability to anticipate and can potentially avoid sharp braking that causes crashes and traffic jams.”

Lower energy or fuel consumption

Skov Andersen cites Japanese research about adaptive cruise control (ACC). He says it shows that you can increase traffic capacity when adding communication. In addition, the smoother ride will mean lower energy or fuel consumption. This also means less pollution. “These are the phases we are going through, and the next step would be fully automated driving,” he says.

As for collective perception, he emphasizes that it doesn’t mean that all cars need to be equipped to share information about unequipped road users: “With 15-20% penetration, we would be able to detect 95-100% of the vehicles, pedestrians, and cyclists. We can also use infrastructure sensors, too, to provide the information, and thus get an even better coverage.”

Collective perception is a new standard this year. “From a functionality perspective it is key, and we have technical standards to support functionality independently of what physical layer is used 5G-V2X or ETSI ITS G5”, he reveals before stressing that C-V2X is only the transmission technology. On its own there is no functionality, and its limitations are spectral.

5G: cellular benefits

5G offers cellular benefits by permitting the fast provisioning of map updates, or remote driving. He finds that “5G people like to demonstrate remote driving to move a car without physically having to wait for someone, but there are a number of liability questions.” For example, the use cases are often within closed environments such as valet parking and in car parks. Secondly, he explains that “the short-range component of 5G-V2X doesn’t provide anything additional to what can be done today. Long-range offers a number of additional possibilities.”

A spokesperson for Audi UK remarks that lower latencies, higher data rates and new as well as improved technology features, 5G-V2X and 5G provide the capabilities to match the requirements by automated driving functions. Audi also believes there is a high safety criticality, which must be met.

The automaker already has various functions and services in its series vehicles in the Chinese market, and comments: “There are lots of new services and (complex) functions on the agenda of the 5GAA, and there is a huge interest in new, even more complex uses cases and functions across the industry.”

Paving the Road to Autonomy?

So, is 5G C-V2X Really Paving the Road to Autonomy? Audi UK says that 5G C-V2X cars get ‘automated’, but it doesn’t make the autonomous. They are, however, connected. “Connected vehicles are the prerequisite to interact with its environment and other road users and therefore a basic ingredient of autonomous driving,” says the spokesperson before pointing out that this requires interconnectivity with each and every single participant.

The automaker believes that a milestone has been set with 5G. However, it’s not sufficient in itself. It’s just the network, the communications layer. So, Audi is right to say there are also other aspect that are required to make the vision of the road to full autonomy a reality. They include rules, regulations, legislation, agreements on standards and network frequencies.

Skov Andersen concludes that cost is also a consideration. He asks: What is the point of an autonomous car if it costs just as much as hiring a driver? There is the possibility that their proposition may not be as attractive an offering as is currently proposed. A comparison would be 3G movies, which quickly lost their attractiveness due to the cost of making them and of viewing them.

Beyond cost, there needs to be coverage to enable information and map updates. Many of these things can already be done over 4G, and even that often suffers from coverage black spots. So, as he suggests, predictability is necessary to prepare for passages where you might be out of coverage.


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