What's the difference between GSM and CDMA?


The iPhone 5 comes in two versions apparently, GSM and CDMA.  The 4S combined the two in one model.  I know that GSM is used by some carriers (AT&T) and CDMA is used by others (Verizon and Sprint), but what is the difference?  Is there any advantage of one verus the other from a user's perspective?  

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Vote Up (20)

Here's a good explanation of this:

The iPhone 5 Has Separate GSM and CDMA Versions, So Prepare To Stay Loyal To Your Carrier

"One of the best things about the iPhone 4S was that it rolled GSM and CDMA into the same baseband. What that means is if you have, say, an AT&T iPhone, it could technically run on Verizon as long as you unlocked it. Likewise, if you had a Verizon iPhone, you could just slap in a GSM pay-as-you-go SIM card if you were traveling in any other country in the world to avoid exorbitant international roaming fees.

With the iPhone 5, though, things are changing. There will be two versions of the iPhone 5, a separate device for both GSM and CDMA carriers. Why? Seems to all be about LTE.
According to Apple’s official specs page, there will be three versions of the iPhone 5. First, there’s A1428 GSM version and an A1429 CDMA version.

They both support LTE, HSPA+ and DC-HSPA, but they do so on different bands, with the 1428 working on AT&T and various Canadian operators carrying LTE support on bands 4 and 17, while the A1429 will work with Verizon and Sprint and offer LTE on bands 1, 3, 5, 13 and 25. The last iPhone 5 is the GSM A1429 variant, and will be offered mostly in global markets."

Vote Up (18)

Really the only difference I notice from a end user standpoint is that the removable SIM card on GSM phones allows switching phones on a carrier by doing little more than switching SIM cards.  Most of the rest of the world outside the US uses the GSM standard, so if you are a traveler, there is a real advantage there.  I actually keep a spare GSM phone around even though my carrier is Sprint, which is a CDMA carrier.  When I travel to Europe, I just buy a SIM card from a pre-pay carrier in whatever country I'm in, and I have a phone that will work during the trip for very little expense.      

Vote Up (14)

The biggest advantage to the the user is your local coverage. Where I live, there is little to no GSM coverage.

Vote Up (11)

The biggest advantage to the the user is your local coverage. Where I live, there is little to no GSM coverage.

Vote Up (4)

i will help you


By the GSM iphone 5 you can unlock it easily by the network provider or a relevant software or by an onlione vendor like ClassicUnlocking.com easily .By an unlocked GSM iphone you can use any other GSM network in other country.It is more suitable for roaming to other country.But the CDMA iphone 5 ,you can't change the network provider easily.

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