I'm on O2 Uk so I'm pretty sure it's a GSM network. I was under the impression that iPhones (at least) could browse the Internet while on a call. But when I switch to Safari while on a phone call I get an alert view saying I can't use data on a call. And it doesn't matter if I'm in 3G Edge or GPRS (the dot) coverage.

Why is this, and why hasn't it always happened? And more importantly how can I change it?

  • I have the same problem. My internet drops if I get an incoming call. There used to be a settings but now there isn't one (LTE on or off doesn't fix it) so I just switch to Android. Don't worry, 1000s have this problem, when I had a quick look at apple pages... Commented Jun 2, 2022 at 14:06

3 Answers 3


"GPRS and EDGE will fail at offering both voice and data, and it might be that you initiated the call on an EDGE network"

True, if the network and the device do not support DTM (Dual Transfer Mode, look it up from Wikipedia). For example, Vodafone network in the UK does support this feature, which works with several devices (phones). I guess iPhone is not one of them, though.


This is coming from an American, but the 3G coverage should allow simultaneous data and voice.

From Apple's Website:

You can tell iPhone is connected to the Internet over a cellular data network if you see enter image description here,enter image description here or enter image description here in the status bar at the top of the screen.

If you're outside your carrier's network, you may be able to use a cellular data network from another carrier. Roaming charges may apply.

Note: If not on 3G, while iPhone is actively transferring data over the cellular data network—downloading a webpage, for example—you may not be able to receive calls. Incoming calls may go to voicemail.

GPRS and EDGE will fail at offering both voice and data, and it might be that you initiated the call on an EDGE network, and moved over to the 3G areas, either way I would recommend resetting network settings on the phone.

Settings>General>Reset>Reset Network Settings

This will reboot your phone, reestablish network connections, and forget your wifi passwords.

  • So a phone will not ring if I'm using the internet, why doesn't it disconnect from the internet and ring, giving the suer the option?
    – Jonathan.
    Commented May 5, 2011 at 18:03
  • From my understanding, for these protocols the internet communication literally blocks the phone connection from being made, so it is not aware of such a connection. It could be in software they could detect you not sending packets and check if you're getting calls, but it doesn't if that is even possible. Commented May 5, 2011 at 18:13
  • Can't the O2 servers (which record voicemail etc) notify the phone over the internet? The solution here is VOIP.
    – Jonathan.
    Commented May 5, 2011 at 18:38
  • Not in the current implementation they cant. VOIP has its own pitfalls, like built in notifications for phone calls while you are in other apps. Commented May 5, 2011 at 18:42
  • The iphone does have notifications for VOIP.?
    – Jonathan.
    Commented May 5, 2011 at 18:43

From my experience here in Brazil's GSM, if you're browsing and then either pick or make a call, the 3G (or even Edge sometimes) continues to work while on the call, though that doesn't happen always and sometimes I do receive the warning as well, not only on safari but anywhere I try to connect.

Somehow seems like the problem is in making the connection while within a call. And that sucks. But I've never could solve it. I could never connect to the carrier internet if I didn't connect soon before entering any call.

While wifi obviously works all the time.

But if everything was working fine before and now it isn't anymore, as hobs said, the last thing you can do to fix it is Resetting the Network Settings.

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