You use what is called "tethering" or "personal hotspot" in the iPhone (version 6.0 and above of their IOS software and Android phones (version 4.0 and above)
(there are a lot of web sites that explain how to use this, you can google a little this word and should find some explanation)
it's inside the settings menu, this way you transform the iPhone or Android phone into a little wireless router, the frame will connect to the smartphone using wifi and then the smartphone send the data to internet using it's 3G network, and this is a wireless router connected to 3G!!
REMARK for the iPhone!!!!!
Read this for making it work on the iPhone with Pix-Star: