Sorry if this is a repost, I looked but didn't find anything.
The GS3 has SVDO and SVLTE meaning it has voice and data over 3G (EVDO) and 4GLTE. The LTE antenna includes GSM 850+1900 bands for voice and data (EDGE only), so the radio is there for AT&T and T-Mobile whether or not the software supports it may be a different story.
It is possible that it has the 900 and 1800 bands for world use as well, the FCC filing makes no mention of it, but it isn't needed in the US anyway. Similarly, the Rezound made no mention of it's GSM capabilities in the FCC filing, but it is quad band gsm.
I attached the radio locations for those who are interested and the section showing svdo and svlte
The GS3 has SVDO and SVLTE meaning it has voice and data over 3G (EVDO) and 4GLTE. The LTE antenna includes GSM 850+1900 bands for voice and data (EDGE only), so the radio is there for AT&T and T-Mobile whether or not the software supports it may be a different story.
It is possible that it has the 900 and 1800 bands for world use as well, the FCC filing makes no mention of it, but it isn't needed in the US anyway. Similarly, the Rezound made no mention of it's GSM capabilities in the FCC filing, but it is quad band gsm.
I attached the radio locations for those who are interested and the section showing svdo and svlte