Wi-Fi at 5 GHz
The new piggy-backing technology uses the same Wi-Fi band that mobile device users are beginning to take advantage of in the home and workplace. That is 5 GHz—the free-to-use band you'll find in newer routers and mobile devices, like tablets and recent phones.
Five GHz Wi-Fi is underused, fast, and well-suited to media delivery in small spaces, like the home. That's why new mobile devices use it.
And it appears Mobile Network Operators (MNOs) have taken a fancy to it too. But in that case it's likely for paid-for use in phones.