You might have read or heard about china phones supporting 3G frequency in the likes of 900/2100mhz, 850/2100mhz, 2100mhz, etc… These are frequencies, kind of like radio frequency wherein your region or carrier supports such frequencies, you have 3G support.
HOW DO YOU CHECK?
Its actually pretty simple, just visit mobile world live. Its a website use to check for frequencies supported by carrier and country.
Thank you and enjoy