Originally Posted by
weekilter
All GSM networks outside of the Americas work on GSM 900 and/or 1800. The US, Canada and many American (North and South) use GSM 850 and/or 1900. A quad-band phone will work on voice services in 90% of the world save for Japan and South Korea. There is some 900 and 1800 in some of Central and South America.
Not completely accurate.
In Argentina, GSM carriers also use 850 and 1900 MHz.
I was surprised to find this when I first visited there.
I'm sure that there are other countries (a few, anyway) that are out of North America that do not use 900 and 1800 MHz.