Cell phones: What is GSM?

GSM

Gatorned,

GSM = Global System for Mobile Communications - which uses "TDMA"
TDMA = Time Division Multiple Access
CDMA = Code Division Multiple Access

The two networks use different ways to "share" or "Divide" a single voice channel among many phones at the same time. The sharing reduces cost for carriers and you.

As stated above, Cingular (i.e. ATT) and T-Mobile (US branch of Deutsch Telecom of Germany) are the primary US/Canada GSM carriers - there are a few other smaller carriers (i.e. Rogers).

But MOST carriers in the US and Canada use CDMA. (Sprint, Verizon, Alltel, Sprint).

Also, Japan decided to be even more different so they have a third network type.

So, if you want to use a phone world wide, your best bet is GSM.
CDMA is pretty much limited to North America

As for your phone, HTC is based in Taiwan, so *most* of their products, especially if HTC branded, are GSM. Check their website if unsure (www.htc.com).

Now for my experiences:

I travel extensively to Asia and use Cingular, with an unlocked Cingular 8525 (AKA HTC TyTN). When I get where I am going, I buy a local prepaid SIM card and swap it in. This is MUCH cheaper. For example, in Malasia I buy a card a a small sundry shop in the airport, for 8.5 Ringet - about $2.50. And it comes with 50 min of time. I can buy refills all over for about 2.8 cents per minute - and that includes calls back to the US!! (they use VOIP to keep the cost down).

And, a little known tid bit - Apparently Congress passed a law last year that requires carriers to supply their customers with the code needed to unlock their GSM phones for international use. That is how I got the code for my current phone. My previous phone (Nokia) i had to do on my own as they refused to help - that was a year ago, so apparently the law is real.

Good luck!