Walking with a smartphone could actually keep you safe from cars

While only an estimated 16 percent of the 7 billion people on the planet carry a smartphone today, it’s looking inevitable that most, if not all, of the world’s population will have one at some point. In that case, if you know where a smartphone is, you have a good idea where the smartphone’s owner is. General Motors(s gm) is counting on that by testing a wireless pedestrian detection system, in hopes of giving drivers more time to avoid potentially hitting a person.

Although both cars and smartphones are filled with sensors, the solution GM is testing doesn’t need any of them. Instead, GM is banking on wireless connectivity; specifically the Wi-Fi Direct standard. Conceptually, cars would be actively looking for Wi-Fi Direct smartphones — and the owners of those devices — and could signal an imminent collision in advance by comparing the two signals up to 656 feet apart.

The concept is similar to Ford’s(s f) own vehicle detection system that uses a different Wi-Fi standard, 802.11p, to help cars detect each other. These Wi-Fi implementations work without access points on a peer-to-peer basis, so they can be used anywhere. Pedestrians will of course need to keep their Wi-Fi radio active on their smartphones for GM’s solution to work but I don’t think that will be an issue.

Wi-Fi generally uses less battery life than mobile broadband radios, for one thing. And we’re clearly moving towards heterogeneous networks — or hetnets — with seamless Wi-Fi offload from traditional cellular networks.