Cars Talk to Cars on the Autobahn

Photo: Deutsche Telekom AG

When my car can talk to your car, and yours can talk to the next, they’ll all be able to substitute shared data for the one thing robots lack: intuition.

Such talkativeness will allow cars to space themselves out, make room for merging vehicles, and vary their speed without setting off bothersome ripple effects in the traffic behind. Best of all, it will let robocars drive (or appear to drive) a bit more boldly: A well-informed car can pass a semi with such confidence that a human observer might almost mistake it for foolhardiness. 

Real-time communications are a prerequisite, and this week the proof was offered in Germany. “This is the first demonstration of car-to-car communication via a high-speed cellular connection with near-5G performance,” Alexander Dobrindt, Germany’s minister of transport and infrastructure, said in a statement. The experiment was conducted on the recently inaugurated Digital A9 Motorway Testbed, a segment of an autobahn in Bavaria, southern Germany.  

There are other ways of wirelessly linking cars, but cellular networks are particularly attractive because they exist already and don’t require a “handshake”—the time-hogging ritual by which two computers exchange credentials. The highway testbed worked on regular LTE service from Deutsche Telekom, upgraded locally with a Nokia system optimized for rapidly moving vehicles.

Kathrin Buvac, the chief for strategy at Nokia Networks, described the mobile-optimized system as part of both the Internet of Things and the next generation of cellular service. “With Mobile Edge Computing, which was developed chiefly by Nokia, we are already integrating elements of 5G into modern LTE networks,” she said.

The company claims that its technology cuts total transmission lag time to under 20 milliseconds, versus today’s speed limit of 100 milliseconds, at best, and several hundred milliseconds, at worst. But that’s counting the relay time from one car to another, via a central cloud. True 5G is often defined as conducting simple point-to-point transmissions with lag times of just a couple of milliseconds.

These smart-road experiments are designed with self-driving cars in mind, and that raises the question of whether mere mortals will have access to car-to-car chatter—or want it. “Too much information” is a complaint that only a human being could make.


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