I'm hoping someone can shine some light on this for me. I'm considering canceling my 3G service for my ipad2 and switching over to tethering using my lumia 920. The ipad is set to backup when it's connected to a wifi network and plugged in. What's keeping it from using my lumia's network to backup if I were to charge my ipad away from my home wifi connection? I can just see me blowing through data if this were to happen. I've seen options on other tablets to only backup on certain networks but that doesn't seem to be the case with apple devices. Any help would be appreciated!