Achieving the goal of connected traffic will involve equipping vehicles to communicate with each other and exchange data directly.
In late 2016, a proposed V2V (vehicle-to-vehicle) communications mandate was issued by the U.S. National Highway Traffic Safety Administration (NHTSA). It would have required an IEEE802.11p modified Wi-Fi standard for dedicated short-range communications (DSRC) equipment to be installed in new vehicles beginning in 2020 or 2021. Since 2016, however, NHTSA hasn’t moved forward with the regulation under the Trump administration, so the door remains open for a competing cellular-based standard called C-V2X to step through.
And it has. While the V2X battle is still ongoing, the 5G cellular camp seems to be gaining momentum. As an example, consider that for the first time in Europe, Bosch, Huawei, and Vodafone Germany have successfully tested the usage of C-V2X on the A9 freeway in Bavaria, Germany. They used a pre-standard 5G network in combination with Bosch’s Adaptive Cruise Control (ACC) driver-assistance system. The real-time integration of C-V2X with the ACC driver-assistance system, proponents say, will deliver more efficient and safer driving.
The C in C-V2X stands for "cellular" and suggests that messages between vehicles would have to be sent through the cellular network, significantly increasing the latency and making it largely unusable for real-time safety applications. Here, however, C-V2X modules also transmit their information directly to appropriately equipped vehicles within a radius of about 300 m. It needn’t go through any intermediate channels via base stations, significantly reducing latency to less than 10 ms.
C-V2X driver-assistance systems like adaptive cruise control benefit from the direct, instantaneous exchange of information between vehicles.
Up until now, C-V2X technology has been used on a real-time alert basis for changing lanes when driving on highways or to get a warning when the car ahead brakes suddenly. In operation, ACC detects a vehicle that suddenly cuts in front as soon as it enters the radar sensor’s detection range.
Furthermore, the adaptive cruise control feature is used to maintain a specific speed that’s set by the driver, using a radar sensor to move at a preset distance to the vehicle in front the ACC vehicle. ACC not only warns the driver, but also automatically accelerates and brakes.
On top of that, using direct communication between vehicles provides information about what’s happening in parts of an intersection not visible to the driver, over the crest of a hill, or on the freeway beside or behind the driver’s own car.
When cars communicate directly and in real time using C-V2X, it’s possible to detect such events sooner. That’s because cars can directly transmit information, such as their position and speed, to all vehicles within a radius of more than 300 meters.
In another positive development for the C-V2X camp, which includes chipmaker Qualcomm, cellular providers, and others, Ford announced at CES 2019 last month a definitive timeline for the introduction of C-V2X communications, which it says will begin in calendar year 2022.