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aajeev

macrumors regular
Original poster
May 7, 2008
111
0
I was asked by a colleague today who is coming from Asia, and is planning to stay in the US for two yeas for school. Well, I know for fact that the iPhone 4S is not locked, so ATT or T-mobile won't be an issue (there is no locking phone over there). Also, we all know that iPhone 4S has both GSM and CDMA built in. My uncertainly comes from that fact that I think I read some where, that with CDMA you can't just simply switch between carriers (i.e., between Verizon and Sprint as you please). So will a iPhone 4S that has been running on GSM network and never used it's CDMA simply work with Verizon by activating it with Verizon? I've searched the internet, and I think 99% of people are more interested in the other direction, going from US to other part of the world...
 
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No, an unlocked iphone will only work on GSM carrier. So your colleague will have to use a GSM carrier with his/her unlocked iphone.

You can call Verizon or Sprint about that matter and see if it will work.
 
I was asked by a colleague today who is coming for Asia, and is planning to stay in the US for two yeas for school. Well, I know for fact that the iPhone 4S is not locked, so ATT or T-mobile won't be an issue (there is no locking phone over there). Also, we all know that iPhone 4S has both GSM and CDMA built in. My uncertainly comes from that fact that I think I read some where, that with CDMA you can't just simply switch between carriers (i.e., between Verizon and Sprint as you please). So will a iPhone 4S that has been running on GSM network and never used it's CDMA simply work with Verizon by activating it with Verizon? I've searched the internet, and I think 99% of people are more interested in the other direction, going from US to other part of the world...

Technically speaking it would work; however, with the US Carriers being the dictators they are it is not possible. Verizon and Sprint both refuse to activate a device, they did not sell, onto their network. He may have more luck with smaller regional carriers or pre paid services?? It doesn't hurt to call Verizon and Sprint and ask, may get lucky and get someone to push it through, I've never heard of it working though.
 
Technically speaking it would work; however, with the US Carriers being the dictators they are it is not possible. Verizon and Sprint both refuse to activate a device, they did not sell, onto their network. He may have more luck with smaller regional carriers or pre paid services?? It doesn't hurt to call Verizon and Sprint and ask, may get lucky and get someone to push it through, I've never heard of it working though.

Thanks guys. Your information is pretty much what I had in mind. I'll give Verizon a call today to confirm, I'll update that once I called them.
 
From http://store.apple.com/us/browse/home/shop_iphone/family/iphone/iphone4s (after you opt for unlocked):
The unlocked iPhone works only on supported GSM networks, such as AT&T in the U.S. When you travel internationally, you can also use a micro-SIM card from a local GSM carrier. The unlocked iPhone will not work with CDMA carriers such as Verizon Wireless or Sprint.

Granted, as stated above, it's not a technical limitation and due to Verizon and Sprint's policies.
 
it's not a technical limitation and due to Verizon and Sprint's policies.
Wrong. It's a technical limitation.

GSM network connectivity is governed by SIM cards. CDMA network connectivity is governed by firmware. Obviously it's much easier to switch between GSM networks on an unlocked device because you can just switch SIM cards.

No known methods to flash an iPhone 4S to different CDMA network firmware exist, although people on various developer forums are working on it (i.e. here and here.)
 
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He can try but i'm sure it won't work on a CDMA network. Does he not want to use it on At&t or TMobile?

I have a 4s on Verizon. If in a populated area that at&t covers with 3g/4g I would say Jordan is on to something with at&t. They will be way faster most places on the 4S with extra features. Should be a little bit cheaper too without taking work discounts, etc. into consideration. The only place a Verizon iPhone has an advantage is if he will be living in the boonies or an area like NYC, Chicago, etc. in a known at&t congested area. If I had it to do over again I would have signed with at&t over Verizon.
 
Thanks guys for the help. I went down to talk to some Verizon representative at the location store, and the answer is NO. So I guess that's that. However, I do think it's not very wise considering all the foreign students coming with an unlock iPhone 4S will just default to either ATT or T-mobile. I'd be happy if I'm ATT signing up iPhone like contract without having to subsidize for it. Even if the contract is terminated early, it's at no cost to me.

@Jordan921: Well T-mbile is going to be slow, and in this case Verizon offers about 10% more discount than ATT thats why I was thinking to try with Verizon.

@ JakeT85: Yes, I agree that ATT has faster speed. But as a Verizon user for the last 2 years, I have not had any issues doing anything I want: netflix, email, stream music, and upload pictures. Personally I'd take coverage, and no drop call over faster speed. Also, inside the building where I work at, nobody with ATT has more than 1 bar if they are lucky. Just speaking from personal experience.
 
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