Using a Verizon iPhone 4s, need to disable CDMA in China???

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Using a Verizon iPhone 4s, need to disable CDMA in China???

Is there an option to select only GSM for the Verizon iPhone 4s? The battery is draining about 10% an hour with the phone idle (fetch enabled, all asynchronous pushes disabled). The carrier on the top left of the phone indicates "Roaming".

Having used other world phone devices in the past (Blackberry), the Blackberry had a mechanism to disable CDMA. Once CDMA was disabled, the battery issue went away. I suspect the iPhone suffers from the same problem.

iPhone 4, iOS 5

Posted on Oct 16, 2011 3:33 PM

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Answer 1

Oct 16, 2011 3:38 PM in response to peddler1000

You are roaming internationally via CDMA - you need internet access for email, etc. or to place/receive calls?

If not, turn on Airplane mode. If you need to access an available wi-fi network for internet access, you can enable wi-fi after enabling airplane mode.

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Answer 2

peddler1000 Author

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Oct 16, 2011 3:44 PM in response to Allan Sampson

It's not clear if the device is roaming via CDMA or GSM. I would like to force it to roam on GSM since based on my prior experience, GSM works much better here in Beijing.

I have an international data plan, so there's no problem accessing data over GSM and CDMA in addition to Wi-Fi.

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Answer 3

Oct 16, 2011 3:46 PM in response to peddler1000

If you have an iPhone 4, you are using CDMA as the Verizon iPhone 4 is CDMA only, no GSM.

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Answer 4

Oct 16, 2011 3:48 PM in response to peddler1000

I'm not familiar with this - with the new Verizon CDMA/GSM "world" phone. Since you have a roaming plan with Verizon, you didn't check this with Verizon about this in regards to the iPhone 4S especially since you prefer using GSM based on past experience when roaming internationally?

Have you checked the iPhone user guide in regards to this? Apple includes a Safari bookmark with Safari on the iPhone for access to the user guide.

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Answer 5

peddler1000 Author

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Oct 16, 2011 6:18 PM in response to peddler1000

@Meg - the new iPhone 4S supports both CDMA & GSM.

@Allan - I spent quite a bit of time w/Verizon (both before I left and since I've arrived in China) and Apple tech support whle in China. Verizon understood the problem but since the phone is so new, had no idea what to do. According to Apple, when roaming, the phone will default to GSM if both GSM and CDMA exist. The second tier Apple tech was not certain about how the switching really worked, and said he would escalate the question. let's hope he does...

Since I've unlocked the SIM card, I'll also try using a local SIM card and see how that changes things.

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Answer 6

Oct 16, 2011 6:20 PM in response to peddler1000

You must unlock the iPhone, not the SIM card, and I wasn't aware the Verizon iPhone was sold as officially unlocked with the ability to use any GSM carrier's SIM card.

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Answer 7

Oct 16, 2011 6:30 PM in response to peddler1000

peddler1000 wrote:

@Meg - the new iPhone 4S supports both CDMA & GSM.

Yeah, missed that you had a 4S in the text of your message. You might want to update your equipment in your profile. It's showing that you have an iPhone 4.

Best of luck.

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Answer 8

Oct 16, 2011 6:32 PM in response to Allan Sampson

Allan Sampson wrote:

You must unlock the iPhone, not the SIM card, and I wasn't aware the Verizon iPhone was sold as officially unlocked with the ability to use any GSM carrier's SIM card.

Historically, VZW has unlocked global phones for existing customers. I haven't gotten confirmation on whether or not they will do that with iPhones. The GSM will still not work in the U.S even on an unlocked phones.

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Answer 9

Oct 16, 2011 6:35 PM in response to IdrisSeabright

Not sure how they can unlock the GSM portion of the iPhone except for any GSM carrier in the U.S. I guess anything is possible, but that is not a full unlock if so.

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Answer 10

Oct 16, 2011 6:39 PM in response to Allan Sampson

I can't say I understand the technical aspects of it, either. However, if you're an customer in good standing, VZW will unlock the global phone so that you can can use local SIMS when you travel abroad. I don't know why the phones won't work on AT&T or TMobile in the U.S. but, they don't. I had this done for my BB Storm.

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Answer 11

Oct 16, 2011 9:18 PM in response to peddler1000

Having the same issue with Brand New Iphone 4S (Verizon) I couldnt connect in Hong Kong and I am now in China with the same issues. I was on the phone with Verzion for half hour and they are clueless. On the Blackberry I was able to manually change the carrier but the iPhone 4S does not have this option. Please advise if you have any updates.

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Answer 12

Oct 16, 2011 9:38 PM in response to peddler1000

peddler1000 wrote:

Since I've unlocked the SIM card, I'll also try using a local SIM card and see how that changes things.

Am I reading this right? Has the OP unlocked the SIM card in the Verizon iPhone 4S? So then Verizon is continuing their unlock policy to the iPhone?

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Answer 13

peddler1000 Author

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Oct 18, 2011 8:35 AM in response to peddler1000

Here's the update: Verizon tech support has confirmed that Apple needs to modify the configuration options so in an area that has both GSM and CDMA, the user can select which network they will use (similar to what can be done on the Blackberry Storm 2, and perhaps other devices). Verizon does not have a timeline for the fix, but said that Apple is quite responsive. Let's hope so...

The initial implementation of the network "attachment" is the phone will automatically roam on CDMA if both GSM and CDMA are present. In a pure GSM environment, the phone will attach to GSM. Perhaps I should travel to Europe instead of Asia.

On another note, my 4s is unlocked and I was able to use a micro SIM card from a local Chinese cell phone in my iPhone 4s.

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Answer 14

Oct 18, 2011 8:56 AM in response to peddler1000

Thanks for the information!

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Answer 15

Oct 19, 2011 8:42 AM in response to peddler1000

peddler1000 wrote:

On another note, my 4s is unlocked and I was able to use a micro SIM card from a local Chinese cell phone in my iPhone 4s.

That's very interesting. You said that you unlocked the SIM, did you have to call Verizon and request the unlock? Can you do that for any country you travel in? Have you been a Verizon customer for longer than 60 days or does the 60 day rumor matter?

Sorry for all the questions but I just want to understand the details.

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