iPhone 4S unable to turn off 3G?!

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.

3G is data. Turn 3G off on the iPhone 4 you can use EDGE data pipeline. On the iPhone 4S you can only turn off data, which is 3G, with no more access to EDGE.

I got the 3G switch back on my 4S

My 4S arrived earlier, and I noticed it missing. But when I backed up my 3GS with that 3G switch OFF, then restored my 3GS to my 4S, the switch is now back on the 4S.

This seems like the only way to get it back.

If you have an older iphone that can handle 5.x:

1) back up the 4S

2) restore the 4S' back up to the older phone

3) let the old phone sync, etc

4) back up the old phone with the 3g toggle off

5) restore the 4S with the old back up and toggle switch comes back

Wrong. I've gotten my toggle switch back. The 4S is perfectly capable of turning off 3G. Apple it's some lame brain wisdom removed it. Probably because Siri talks to apple almost anytime you use her. So apple probably wanted Siri to be fast.

This is an EASY fix for apple:

1) Add the 3G switch back

2) if the 3g switch is turned off AND there is no wifi connection, Siri auto disables.

VERY.. VERY simple solution

I tried siri over Edge with no wifi.. she takes.... F O R E V E R... so that's probably their reasoning

For the last time: 3G is NOT ONLY data. It is a whole different transmission medium for calls AND data. If you turn off cellular data, you will still be using the 3G service for calls! Turning off cell data does not turn off 3G for calls.

Battery life for talk time on 3G is about half of what it is when it's on Edge. And without the 3G toggle, you are still forced to use 3G on calls, even with cell data turned off!

You know how you can test this? Go to field test mode. On Edge, you'd see blank values for UMTS (3G) and values filled under GSM (Edge). When on 3G, UMTS data will be displayed and GSM is blank. Turning off cell data (while on 3G) and going into field test mode will show you that you are still using UMTS, not GSM.

A second way to test this: If you are in a low 3G coverage area (1 or 2 bars) but a strong 5-bar Edge area and turn off cell data while on 3G, you'll still see low signal if you turn cell data off. Signal strength hasn't changed because it's still on 3G.

Last way to test this: GSM causes interference (that buzzing sound you hear near speakers for example) because of the pulses it sends while 3G uses a non-pulsating signal. Turn cellular data off (while on 3G) and your phone still won't create interference.

So for the last time people, stop saying turning off cellular data turns off 3G. It only turns off data. You won't be able to use the internet in whatever capacity (GPRS, Edge or 3G) but you'll still be in whatever mode you where prior to hitting that switch! So all your calls will still made on UMTS even with cellular data turned off, draining your battery a lot faster than when making those same calls on Edge (x2 faster assuming both signal strengths are excellent).

Not to mention that if you're in a low 3G signal area (but very strong Edge), you'll still be stuck with that low signal for all your calls and your battery will drain even more as a result.

I personally always keep my phone on Edge and only switch to 3G when needing to use the internet. Because of this, my battery is spectacular. I easily come back home at the end of the day with at least 70-80% battery left on my phone. If I keep my phone in 3G mode and use it the same way, I'm down to 30 or less by end of day. Not having the 3G on/off switch on the 4S was the only deal-breaker for me and as a result I had to return it.

They'd better bring it back because this is a big issue, especially for people in low 3G signal areas who are now stuck on 3G all the time. I'm sure the battery issues in part are caused by this, because in low-signal areas the antenna is using a lot of power to maintain its connection.

@Adnan,

Thanks for posting the excellent description of 3G mode of operation. There is a great deal of misunderstanding on this topic. Many people seem to equate "3G" with "data", which it's not.

Anyone interested in a deeper dive into 3G, 4G, UMTS and other alphabet soups involved in the iPhone 4S should read Brian Klug's article here:

http://www.anandtech.com/show/4943/the-iphone-4s-hspa-when-hspa-is-real-4g

And I agree with your hypothesis re the potential impact on battery issues. In areas with low 3G signal levels, the iP4S radio will consume more power attempting to maintain the cellular connection on 3G. I surmise that Apple has adjusted the 3G-EDGE fallback threshold to stay in 3G mode at lower signal levels (compared to previous iPhones), for the reason that TallBear suggests two posts back. In other words, they've optimized for Siri operation, not battery life. While I can understand their rationale for doing so, I also hope they restore the 3G toggle option on the iP4S. Not only can it extend battery life, but it is extremely useful when traveling out of region.

Others who feel the same way should provide direct feedback to Apple here:

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