This may be a stupid question (cell phone amateur) but.....

[pierretong]

if you buy a GSM phone somewhere other than AT&T, how can you tell if you can get 3G on AT&T?

[reveries3]

Check to see if the frequencies that the phone has for 3G are the same frequencies that AT&T uses for 3G.

Sent from my HTC Panache using HowardForums

[pierretong]

the frequencies are 850/1900 ?

[kecel]

Their 3G frequency bands are UMTS 850/1900, GSM 850/1900 is 2G.

[PhotoJim]

Mind also that some phones support some of the frequencies but not all. For example, I have a Nokia Nuron that supports UMTS 1700 (AWS) which T-Mobile USA uses, and UMTS 850 which AT&T, Rogers, Bell, Telus, SaskTel and MTS use. However, in some areas there is 1900 MHz UMTS coverage and not 850, and in some areas you'll get better service having both 850 and 1900 even though an 850-only device will work.

[pierretong]

so would a Samsung Galaxy S II work with AT&T 3G or 4G? The Amazon website selling them says "HSPA+ 21Mbps/HSUPA 5.76Mbps, EDGE/GPRS Class 12, Quad band GSM 850/900/1800/1900, Quad band UMTS 850/900/1900/2100"

[PhotoJim]

If unlocked, that phone would work well with AT&T.