iphone - how to disable network power saving mode

Whilst making a Game Center GKMatch game I've come to realise the iphone networking hardware will go into power save mode if I don开发者_如何转开发't transmit/receive anything within 100ms (or something like that). Coming out of power save mode can take 500ms, which is bad. To prevent this from happening I just send something periodically. But I don't REALLY want to do that because it uses up people's monthly 3G data usage.

Is there some way to programmatically disable power saving for networking?

I haven't tried this, but can you send something to localhost (127.0.0.1) periodically, to keep the connection up, without going over WWAN or wi-fi?