CDMA vs. GSM, SIM Cards and How to Save on International Phones

If you had a cell phone, you could tap that...
Most American phones can't get a signal in other countries, and when they do, the calls are still expensive.  Having a quad-band GSM phone, though, will let you swap SIM cards in order to use local carriers at ridiculously cheap rates. You can get basic quad-band phones from your cell phone provider or for little as $60 from Amazon, $35 from Cellular Country or $29 from a Mobal Phones.

[Click here for my article on how to knock $400-1000 off your yearly cell phone bill]

Because you're reading an article on international cell phones, I'm going to assume you're American.  If you're not American, you don't need this knowledge because you're already using a phone that works globally and believe that dropped calls are urban myths.  Still, non-American, I'm going to tell you something that will blow your mind: in America, we sign an exclusive two year contract with one cell phone carrier, and then that carrier allows us to only choose from a select number of phones provided by the companies it has partnered with.  Our phone will only work with that carrier, and if we want to leave our carrier before the contract is up, we have to pay several hundred dollars in fees to do it.  Yes, I know.  Hard to believe in the land of freedom and choice, right?

Americans, this will blow your minds: the rest of the world does it differently.  In the rest of the world, you buy a phone of your choosing--any phone of your choosing--and then pick a carrier that you want to use.  This carrier gives you a SIM card (Subscriber Identity Module) that you insert in your phone. This card tells your phone what carrier it should communicate with, as well as telling the carrier which phone is calling. When you want to switch carriers, which you can do at will, you simply switch SIM cards.

I didn't learn about all this until I was sent to Ukraine by the Peace Corps.  There, I found a country with little in the way of political freedoms, but plenty in the way of cell phone freedoms. Competition between the cell phone companies was so fierce that they were constantly undercutting each other with cheaper rates and bonuses, causing customers to change their SIM cards more often than they changed their underwear.  I switched providers no less than four times when I was in Peace Corps, and I changed my underwear no less than...  Well, I didn't change my underwear.  Ever.

[Click here for my article on how to call more than 50 countries for free]

What this means is--with the right phone--you can pay local rates to call and text while you travel.  In Ukraine, that was $0.10 a minute to call and $0.002 to text.  No, I didn't mistakenly add an extra "0".  It really was two-tenths of a cent per text! And yes, you can do this with an American phone, but not without a bit of knowledge. There are two major mobile technologies in use in the world, both of which unhappily coexist in the United States:
  • CDMA (Code Division Multiple Access)  
    • Used by Verizon Wireless, Sprint, U.S. Cellular and Virgin Mobile.
  • GSM (Global Systems for Mobile Communications)  
    • Used by AT&T and T-Mobile
CDMA is the dominant technology in America, but GSM is the dominant technology in the rest of the world. As of now, fewer than 50 countries have significant CDMA coverage, and they are mainly in North America and the Caribbean. Japan and South Korea also use CDMA, but on different frequencies than are used in America. This means that a cellphone built in Japan for an American market will not work if you take it back to Japan. Oh sweet, sweet irony. Major carriers like Verizon would like you to believe that their CDMA phones work worldwide. Verizon's global coverage map makes it seem like its phones are usable all over the world, including most of Europe:

Verizon's Global Coverage Map is a lie.  So was your first relationship...
If there is at least one CDMA tower available in a country, they feel comfortable saying there is "coverage" in that country.  Trust me, though: it's unlikely you'll get a signal.  Moreover, even if you are in a country that uses CDMA and do get a signal, you won't be able to use the local carriers because most CDMA phones don't have SIM cards.  This allows a company like Verizon to be your sole service provider, which is how--for example--you could be in a CDMA country like Belize calling another Belize phone over a Beliziean network and get charged $2.89 a minute.  Un-Belizeable!  Ignore that I just said that...


Blue is 850/1900MHz.  Green is 900/1800Mhz.  Red proves that Japan hasn't forgiven us.  
So what you're looking at it wanting a GSM phone.  After all, GSM is in use in more than 190 countries.  
If you are AT+T and T-Mobile customer, this is the technology you are using.  Don't get too excited, though, because having a GSM phone does not automatically mean it will work in other countries. GSM has four frequency "bands": 850, 900, 1800 and 1900MHz.  The 850 and 1900Mhz bands are used in the North America, Central America and the Western half of South America, and almost everywhere else in the world uses the 900 and 1800MHz bands.  If you have an American GSM phone, it likely is "dual-band" and will only work 850 and 1900Mhz countries.

If you are like me, though, you want a phone that can work on all four bands.  These are called "quad band" or "world" phones.  If you have an iPhone, for example, you have a quad-band phone.  Possession of one of these means you will not only be able to use your phone in America, but in over 190 other countries.

How do you get one of these phones?  Well, you have some options:
You may have noticed the word "unlocked" used several times in the options. That's because if you get your phone from a carrier--no matter which carrier--it will have been programmed to only work on that carrier. You can swap out the SIM card, but it simply won't load.  If you want to use it with other carriers, you'll have to get it unlocked.  Luckily, this is fairly straightforward. The policies differ by  company, but it is usually a matter of calling them and asking them to do it.  Provided you have been a customer for long enough and are in good standing, they should send codes to the phone to unlock it.  If they won't, you can go through a company--like Unlock To Talk--that specializes in unlocking phone.  Be warned, though, unlocking your phone yourself usually voids your warranty.

If you're wondering what phone I use, it's an unlocked HTC Sensation.  It was splurge, but I wanted a powerful smartphone with a high-end camera, and--as I pointed out in my article on Ten Travel Items You Can Replace with a Smartphone--having a smartphone can save significant weight and bulk on a trip.  Plus, I can use it to call and text America for free over wi-fi. Yes, I am bragging. No, you can't use my phone.  You've just been robbed?  Well, go to the police station.  The police robbed you?  Oh.

Happy calling.