Q: How do I turn off 3G on the iPhone 4S?

Have a look here for a mockup feature for fast 3G/Wi-Fi toggle. Hopefully with enough backing Apple will listen to it's users.

The problem isn't the availability of a toggle for mobile data. It's a toggle to disable 3G. There already is a toggle to disable cellular data to restrict all data to Wi-Fi.

I agree entirely, I was frustrated that Apple removed the 3G toggle in iOS5. Unless they bring back that back the Data toggle is the only option.

The 3G toggle could also be listed with Data/Wi-Fi as in the mockup.

No the toggle is not removed from iOS 5. It is removed from the iPhone 4S, only. The iPhone 3Gs and the iPhone 4 still have the toggle.

See, the problem is in the "modem firmware" for iPhone 4S. "Modem firmware" is  the internal software that controls the phone or cell radio portion of the iPhone, and isn't compatible with previous iPhones. Nor is the "modem firmware from previous iPhones compatible with the iPhone 4S, because the 4S uses a different cell radio chipset, it is a hybrid cell radio. Also, the cell radios between the previous GSM iPhones are different manufactures, since the iPhone 4S was a departure from cell radio manufacturer Infineon, which adds to the modem firmware incompatibility.

The 3G/2G toggle API, most likely would be part of the modem firmware. When the GSM iPhone 4 gets iOS 5 installed, it a modem firmware written specifically for the Infineon cell radio chipset, while the iPhone 4S on iOS 5+ gets modem firmware specifically designed around the Qualcomm cell radio chipset. The question that should be asked is if the Qualcomm radio chipset hardware can even support such a 3G/2G toggle. Most likely it can't and may have been an oversight by Qualcomm or a technology hurtle that couldn't be overcome. There are competitor hybrid phones that also use the new Qualcomm manufactured hybrid radio chipsets. The key would be to find out if they have a GSM 3G/2G toggle like ordinary EDGE/UMTS/HSPA phones.

Thanks for the info TM, very interesting.

I'm still waiting on TallBearNC to post his instruction on how he got that 3G switch back.

On iPhone 4S, 5.0.1?

Yes, read through the last few pages.

He also put up som screen shots of the switch back.

I hope that's genuine (ressurect 3G toggle). Will be doing that in a heartbeat :¬)

The same here, my 3G coverage is terrible. So bad that even when I have it the phone says no mobile data or internet.

Then drops to No Service or a constant Searching... when it can't auto switch to EDGE which is nearly always at Full bars.

Me too for TallBearNC to post his instruction on how he got the switch back.

Plz buddy.. its been a long waiting...

Read the Apple Support Communities terms of service. I don't think they will allow those instructions to be posted.

In fact here's a link to Apple's official statement on the issue;

http://support.apple.com/kb/HT4203

I hope this helps.

TallBearNC only one unverified low resolution image of a settings screen with a 3G switch. There is no proof that it a screen shot from a 4S and even if TallBearNC was able to place a 3G/2G toggle switch on an iPhone 4S settings screen, there is no proof or is it verified in any way that the toggle would actually toggle anything. But, go ahead believe the magic.

Apple support forums are not a direct communication channel to Apple. The best way to contact Apple is through the feed back forms, not here. This is customer to customer forum space.

Here's a link to the feedback form:

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