Why do self-driving cars need 5G

Self-driving cars: who needs 5G?

With the new generation of 5G mobile communications, a question arises that many mobile communications users have already asked themselves with 4G: Do you really need that? The mobile communications industry naturally answers this question with a “yes” and cites the automotive industry and the self-driving car as key witnesses. However: The famous Google Car drives without a cellular connection and is only based on its sensors. It drives slowly, but it drives.

LTE and WLAN offer alternatives

In Austria, WiFi boxes will soon be communicating with cars.
Image: Asfinag And even if you want to use radio technology to support vehicle control, there are alternatives. For example the already finished standard C-V2X, which uses LTE. Or the WLAN standard 802.11p and, based on it, the “Dedicated Short Range Communication” (DSRC), also called ITS-G5. This means that traffic reports and navigation data can be transmitted to the car, for example, and mobile news and entertainment services are also conceivable. One application that has already been used for the WLAN service is toll collection, as is common in Italy, Austria and France, for example.

In March of this year, the EU Commission also proposed that networked driving should initially be based on the WLAN standard. The mobile phone providers in particular, but also car companies such as BMW, have resisted this. They prefer cellular networks as a basis.

G5 vs. 5G

At least among cell phone operators, the reaction is understandable. You are building a new technology for a lot of money and want to see it used. And at least on paper, WLAN technology is inferior to LTE-V2X and, above all, 5G. The G5 is also quick to react and works in a specially reserved frequency spectrum of 5.9 gigahertz. And it currently even offers a significant cost advantage when it comes to equipping vehicles. However, it is significantly slower in terms of data transmission and is only considered a temporary solution. Above all, it has by no means been clarified how such a system should be financed across Europe.

LTE-V2X, on the other hand, is considered by its critics to be not yet fully developed, and a lack of robustness is attributed to it for rough car use. But 5G also has its problems: the transmitters are expensive and the transmission process is more complicated than with WLAN. For example, due to the frequencies used, there are still problems with accommodating the complex reception and transmission technology inconspicuously and, above all, efficiently in the car.

The fact is, however, that wireless technology, regardless of whether it is LTE-V2X, 5G or ITS-G5, has many advantages. In this way, the cars can also communicate with one another, for example to access the sensor data of the vehicle in front and thus increase their own range. Emergency services can send a request to clear the emergency lane in front of them. The vehicles can get radio boats that report the position to other cars. This can, for example, increase safety on confusing exits or in front of hilltops.

Austria rushes forward

The Austrian autobahn operator ASFINAG is meanwhile really nailing it and is relying on WLAN technology. The company plans to build up to 500 WLAN boxes next to motorways and expressways by 2023. According to ASFINAG, this will enable “important information to be sent out and received by vehicles with WLAN capability” in the future.

However: 5G is not yet out of the running. The decision to rely on this technology now has no impact on other, future complementary technologies, such as 5G cellular technology. ASFINAG Managing Director Bernd Datler is convinced that “WLAN is mature and secure”.

Which is why 5G will still find its way into the car

ASFINAG gets a supporter from VW. Volkswagen has already announced the series introduction of WLAN technology in one of the next vehicles. Other manufacturers are also planning to incorporate WLAN technology in the next generation of vehicles, for example to support semi-automatic driving in truck convoys (“platooning”). Only the first vehicle takes over the steering. All other drivers then have a break and driving in the slipstream saves a lot of fuel. In addition, the distance between the trucks can be reduced to 15 meters, which significantly shortens the truck columns and improves the flow of traffic. The system is still being tested, however, and there are still a number of questions to be clarified. Alexander Doll, Deutsche Bahn's board member responsible for freight transport, logistics and finance, estimates that it will take until the mid or late 2020s for the system to be ready for practical use.

Everything for security

In Austria, the technology is to be used as two-way communication. Information can be sent from the vehicles to ASFINAG so that other road users can be better supplied with updates along the route. ASFINAG is primarily concerned with safety. For example, information about lane closures, construction sites, speed limits, breakdowns or accidents along the route can be sent directly to the vehicle and displayed there via the on-board computer. Information sent by the operating company is automatically translated into the language of the vehicle's country of origin.

Platooning is still in the test phase.
Image: picture alliance / Bernd Settnik / dpa-Zentralbild / dpa So you don't need 5G? Frank Fitzek, holder of the telecommunications chair for communications networks at the TU Dresden, thinks so. In an article for the website car-it.com he says: "Without 5G, you will have to do without a lot in highly automated driving, safety and rapid progress, for example."

5G enables new applications

There are applications in which the 5G standard with its short latency times and reliability seems to be indispensable. Already a popular showcase: the remote control of vehicles, where minimal latency is important. Such control could become important in an emergency.

Or the example of city traffic: At traffic lights, 5G vehicles could all start driving at the same time. The accordion effect is avoided and the flow of traffic is optimized. At least in theory: Hand-controlled vintage cars are then probably no longer allowed to wait in front of the traffic lights.

And for these visions to come true, 5G must be available across the board. But it will take a while until then. A time when the car companies want to continue selling innovative cars. And they will then be equipped with the available technology. So it will probably turn out as Datler predicts: 5G will find its way into the car of the future, but only as a supplement to existing systems.

You can read more about LTE and WLAN technology for autonomous driving and the political dispute behind it in another report.