Hey guys this is my first post on this forum, but don't assume I'm retarded yet.

Previously a lot of people have been saying that the iPhone CANNOT be used in a CDMA network because even with an r-uim, the radio inside the iPhone is GSM.

But here's why I'm bringing this up again now:
The iPhone was released for Korea (KT Telecom) november of last year.

So what you ask? Well KT Telecom, like the rest of korea, uses CDMA ! This MUST mean, then that the Korean iPhone is equipped with a CDMA radio, and utilizes an R-UIM.

Now I'm not sure if the operating bands are different from korea and verizon/sprint, but if they were: wouldn't one be able to import a korean iPhone, unlock to verizon/sprint, and then have a fully functional CDMA iphone?! I mean fundamentally speaking the Korean iPhone DOES have a CDMA radio.

Furthermore, Update – Use Your iPhone in Korea Now (Not Just WIFI) | iPhone in Korea seems to imply that it IS indeed possible to somehow use a GSM-equipped iPhone in korean CDMA networks?

I mean, if this were true, it would make sense why KT Telecom is telling foreigners that they can't buy iPhones in Korea.

Also, if the iPhone was really CDMA in Korea, I can very well see how a CDMA iPhone could be very possible this coming year in the USA. I mean, apple would basically have already done the hard work (R&D), right?

Someone please correct me and tell me I'm insane.

As far as I can tell KT Telecom offers a UMTS 1900Mhz W-CDMA 3G service. This is quite similar to the service offered by AT&T in the US.

This is not a GSM system but builds heavily on the GSM technologies, at the same time adapting some of the radio innovations from CDMA.

This is why KT Telecom can sell iPhones, they are in fact identical to the ones in the US (except probably locked to KT Telecom)

T-Mobile's problem is that they are running a UMTS 1700Mhz/2100MHz 3G service and are pretty much alone in using the 1700MHz band for 3G.

A couple years ago, one of Brazilian mobile operators (Vivo) was the only one operating as CDMA. They started a migration to GSM but kept their CDMA network running -- part of a customer migration service as demanded by the government. This way, any CDMA phone still works only on their network but they are also able to sell GSM phones, which includes the iPhone.

Maybe KT Telecom is also running GSM on par with their CDMA network. Not to offend Korea, but I don't believe Apple would do such a change on their phones to put a different radio board -- plus different basebands and a lot of extra work -- only for Korea.

Korea, like Japan, migrated to W-CDMA(UMTS) ages and ages ago. They were the second ones to implement a production W-CDMA network.

Originally Posted by fireshark

Korea, like Japan, migrated to W-CDMA(UMTS) ages and ages ago. They were the second ones to implement a production W-CDMA network.

Korea's Samsung was a leader in providing cheap WCDMA network equipment at the beginning of the 3G transition.

The migration to 3G was supposed to standardise networks worldwide, however some countries had already used for something else the standard 2100MHz band that Europe was proposing to use for 3G and as a result some deployments of W-CDMA/UTMS were on other frequency bands. The less common of these being (1700 MHz, 800Mhz - Japan, America) so not all phones support these frequencies.

Korea South does not have any GSM networks. There are 3 operators there - SK Telecom, KT & LG Uplus. While all three run CDMA networks, SK Telecom and KT run W-CDMA networks too. The iPhone available in Korea South runs on these W-CDMA networks and not their CDMA networks.

Can somebody tell me as to why iPhone 4s and iPhone 5 does not take a CDMA R-UIM just as it takes a GSM and W-CDMA SIM & USIM ?