Q: iPhone 4S unable to turn off 3G?!

If you took the time to read the previous post then you would know this will NOT be possible with the 4S for the reasons already provided. This will NOT change with the 4S.

But mine is unlocked iphone4s, which only supports GSM! I don't see any difficulty to add the turn on/off switch. For those with an GSM/CDMA combined sim card, the switch can simply be shown as unavailable. 

<Sigh> The chip doesn't support manual switching from everything I've read. Therefore, it's not a question of hiding anything.

So what? Locked or unlocked has no bearing on this.

Which part about having a combined GSM/CDMA chip do you not understand?

There is no option on the iPhone 4s, to turn off 3G. If there is a way to do it, I cannot find it.

On an iPhone4 and iPhone 3GS running iOS5, you are able to turn off 3G off in Settings> General> Network - as seen in the screenshot below.

This is a problem. Why? Because, for instance, when you're sitting on the beach at Nanny Cay, Tortola (British Virgin Islands), and facing the AT&T Cell Tower in St John (USVI) 2 miles away, you are able to get a bar or 2 of signal strength and 3G. When you initiate the call, the signal drops to nothing,the call fails and the phone goes into "Searching" mode to find a network and if you have an international plan, the network it chooses is "Lime" which is Cable & Wireless (BVI) and if you make the call it costs $1.99/min. And in order to get back to AT&T's US Network, you have to go into settings and force the phone back to AT&Tand try again and all of this takes up to a minute or two, which is a lifetime, when you're trying to simply make a call and get back to your vacation, or your life, or whatever it is that you do.

If you turn off 3G on the iPhone 4 or 3gs you get 5 bars and hardly ever drop a call. So this is one good reason why you should have the ability to Turn Off 3G on the 4s.

Also, turning off Cellular Data, to my knowledge, does not turn off 3G on the 4s or any other previous version of the iPhone.

From the customer's perspective, this is not user-friendly and causes trouble. That is the point!

No, the point is you don't get it.

This is a combined GSM/CDMA chip limitation.

I need to correct myself: My last sentence, I think is not accurate:

"Also, turning off Cellular Data, to my knowledge, does not turn off 3G on the 4s or any other previous version of the iPhone."

I think turning off "Cellular Data" DOES turn off 3G on all models of the iPhone including the 4S.

Allan Sampson wrote:

 

This is a combined GSM/CDMA chip limitation.

@Allan,

The baseband chip in the 4S is the Qualcomm MDM6610 (per iFixIt teardown). My research indicates that this chip should be capable of being configured for EDGE operation (i.e. disable 3G on GSM network). I'm curious to know the reference you've found that states that the chip is limited in this regard.

Thanks a lot.

No it does not. Turning Cellular Data off turns cellular data off only.

Provide the reference that indicates this - with the chip being available in any other cell phone that includes the option to turn 3G access off.

I'll have to find my reference about the CDMA chip not including the option, which the CDMA iPhone 4 does not include.

Turning off Cellular Data (iPhone 3gs/iOS 5.0.1), will make "3G" disappear in the status bar as shown below and you will be unable to send/receive mail and/or connect to the Internet in a web browser and that is the basis for my statement that turning off Cellular Data does turn off 3G.

Turning Cellular Data off does turn off 3G data or internet access via the carrier's cellular network since cellular data access is turned off. The GSM portion of the iPhone 4S also supports EDGE and GPRS access. Turning Cellular Data off also turns off EDGE and GPRS data or internet access via the carrier's cellular network.

Turning Cellular Data off turns cellular data or internet access off entirely via the carrier's cellular network - via 3G, EDGE, or GPRS.

It's dependant on the carrier.

It does turn 3G off. It turns off all cellular data. You can make calls and text, but no data. What do you think 3G is? It's data and voice. Turn off data and you still have voice.