I guess it's possible to cam from your phone, though I'm not sure I'd recommend it. If your internet connection isn't so great, and improving it (by paying for faster internet) isn't an option for you, at least you know not to bother with splitcamming (broadcasting live on 2 or more cam sites simultaneously).
Often times when I see this question asked, other cam girls will suggest that you also consider filming video clips. For recording the clips, you don't have to be connected to the 'net. You just need your webcam (I use Logitech HD C920) and whatever video editing software you choose. The only time you would need to connect to the internet is when you're ready to upload your clips to your Clips4Sale store, ManyVids, IWantClips, or wherever.