Online real time fast paced iPhone/Android game. Possible/Stable?

I don't own either device. I've only played angry birds once and that was on a friend's device.
I've never seen a multiplayer game that wasn't turn based.
I have an idea for a multiplayer game that is real time and fast paced.

Will such a game be stable.

I'm under the assumption that connections speeds aren't that fast&stable.

please let me know of your experiences with online multiplayer hand held games!