I assume they mean the 900mhz band in the US. How is a cell phone supposed to communicate with the Beartooth? If its not a cell tower, the phone only knows bluetooth and wifi on 2.4/5Ghz.
Piggybacking here but the FAQ is painfully vague. On the question of what phones does it work with their answer is:
> Beartooth pairs with both iOS and Android smartphones, as long as the operating system is up to date.
Which is a pretty much useless statement on Android especially since they would know what API level their app targets...
It certainly sounds like it'll use Bluetooth though and makes sense as a bridge between the two devices. The only other real option would be Wifi or if you wanted to be weird for the sake of it you could probably do it through NFC.
My GoPro creates a wifi network and the phone just auto-connects to that to control the GoPro. So certainly the Beartooth could create a wifi network that the phone connects to and essentially sees the Beartooth as a traditional wifi network.
True it's certainly an option though for low rate text and data like the Beartooth is using WiFi is a bit of overkill and the power overhead makes Bluetooth more appealing than Wifi. That and how much they repeat 'pair' instead of something like tether made me think it was probably Bluetooth.