Can you force iphone to look for 3G more frequently.

Post are there any settings that will cause make an iPhone search for a signal better, my iPhones lose signal in quite a few areas around where I live, but my android phones do not, so I know my carrier has a signal in these areas, but I need to make the iphone search for it, and on my route to town, or walking the dogs, I could end up doing this about 10 or more times, where as the android phones lose signal once and only for a few seconds, before someone says just use the android then, its a nuisance carrying two phones around, as the iPhone is the main phone I need to use.

I have the same issues as you @ janitor, with my iphone 4 on the '3' network & my sony xperia z on vodafone's network.

I put them into airplane mode and then switch airplane mode off again and within a couple of seconds, I have 3G again. But it's right pain in the a to keep doing that.

So it would be great if it's possible to find a way of making them search for 3G more often.