Volkswagen Group will include WLANp — a wireless system to link cars to each other and roadside infrastructure — in all its cars in Europe beginning next year.The decision, announced on February 15, might help to establish wireless LANs, rather than cellular networks, as the standard mechanism for so-called V2X, or vehicle-to-everything, communication. Automakers and regulators are weighing the two alternatives for V2X, which is expected to improve safety and traffic flow.

VW will provide WLANp as standard equipment at no extra cost on all its personal and commercial vehicles. It says the move will help create a broad network of information on traffic risks and promote accident-free driving. Volkswagen Group is one of the largest automakers in the world, with 2017 sales of 10.7 million vehicles.

V2X can help cars “see” each other even where buildings or other vehicles block the view, including around corners and in highway passing situations. It has a range of hundreds of meters and can reach farther than the radar and Lidar systems being built into driverless cars.

If one car is about to run a red light and another is nearing the intersection at a blind corner, V2X in both cars could generate an alert — or make either car stop, depending on how much automation was built into the cars. It could also send a signal from one car to the vehicles behind it when the brakes are applied so they can automatically slow down or generate a driver alert.

V2X links could also help vehicles see pedestrians with mobile devices and communicate with infrastructure like traffic lights and warning signs. Wirelessly linked trucks could form convoys that roam the highways together to run more efficiently.

(Think speed control to maintain a safe distance, not drivers conspiring over CB radio.)

But while regulators and industry generally agree on the potential for V2X, there’s less harmony over what system to use.

WLANp is based on IEEE 802.11p, part of the standard behind WiFi. Its proponents say the technology is tested and ready to go. Regulators in both the US and Europe have used it in developing standards for future cars and infrastructure and have set aside similar frequencies for the radios to use. The National Highway Traffic Safety Administration (NHTSA) has proposed requiring an 802.11p-based system called Dedicated Short-Range Communications (DSRC) in all US vehicles. All these steps could help clear the way for wireless LANs to show up in all new vehicles and infrastructure.

But recently, some major automotive tech suppliers have started to say cellular, or C-V2X, may be the best, fastest, and most secure way to go. Cell-based systems, especially with upcoming 5G capabilities, could work better than wireless LANs and ride the massive wave of cell-chip manufacturing to low cost and wide availability, they say.

Qualcomm, which already makes 802.11p chips, is promoting C-V2X as a technology for both communication between cars (on those dedicated frequencies) and links to cellular networks. The 5G Automotive Association (5GAA), which includes Audi, BMW, Daimler and the biggest cell network suppliers, plus Qualcomm and Intel, is also pushing for this approach.

— Stephen Lawson is a freelance writer based in San Francisco. Follow him on Twitter @sdlawsonmedia.