Q: Iphone 4s - 3G connection disappears after using wi-fi

I finally changed provider (using a prepaid card, at least for test purposes), and this works perfect! So after trying:

1) upgrade from 5.0.1 to 5.1

2) complete reset

3) new SIM from same provider (same telephone number)

4) new SIM from same provider (other telephone number)

5) new iPhone

I now seem to have located the cause: it is the provider!

Hans

My opinion - in all of this cases main cause of problem is operator.

I encountered same problems in roaming in Vietnam (Hanoi, I'm don't remember a operator name). In my home cell network (Moscow, MobileTeleSystems) all working ok.

Vladimir

After iOS 5.1 the problem remains, but I think that I've found out that the problem appears only with 802.11n Wi-Fi. With 802.11 "b" or "g" there is no problem. If the problem is the provider, how to fix it?

To add another finding: no problem at all when switching off 3G. In this case, the phone switches perfectly between wifi and cellular data (Edge). Could it be that the iPhone has difficulties to switch automatically between Edge and 3G?

APPLE FIX THIS!!!

hi man,

id need a favour. i need a telia simcard (no credit necessary), but i cant buy it in my country (czech republic). So i thought if any chance, you could send me one. Of course Id pay you in advance. this is no spam, so please contact me, if you got interested

Just started having this issue also.  Going to try all "fixes" and will report back.

iPhone 4S, iOS 5.1, BELL CANADA is the service provider, same problem, 3G will not kick in after being in my home WiFi.

I have to completely power off the phone and reboot, then the 3G works. Very annoying when you think you are on 3G and are not, you have to keep checking. Not very impressive Apple.

NOTE: My older iPhone 4 does not have this problem ! I have trouble believing that the different service providers around the world are the source of this problem.

This *****! Apple fix it! God ****!

Fix fix fix fix it....

I am also having this issue on UK Vodafone. Seems to happen randomly, turning flight mode on and off resolves it for a day or so.

This is not a solution. It should just work fine.

I can't be true that, if I leave a Wi-Fi place, I have always has to check if my 3G comes back!

That's a huge issue.

I think this issue not appers if the Provider search is set "automatic".

Well this is not a real solution for me, because I live at a place where I get abroad networks and I would have to pay for this if I sent a message in that network.

So, APPLE FIX IT! I can't use provider settings "automatic"!

If you have the same issue feedback it! Weekly!

Apple has to react!!!

http://www.apple.com/feedback/iphone.html

New iPhone 4S, BELL CANADA is the service provider, same problem, 3G will not kick in after using WiFi for a while.  3G kicked back in after I turned WiFi Connection Off and then back On in the Settings.  Very annoying!  Don't know if this solution always works as I just received my phone.