当我看到类似的 link 发布在另一个论坛上，但这在我的手机上没有工作。
I bought this phone in India and brought it home to USA. In India I had no issues in connecting to 3G network but after coming back to USA I am no longer able to connect to 3G network (AT&T). I know the phone operates in a different frequency but I wanted to know if there is a way to tweak this.
I got excited when I saw a similar link posted on another forum but that did not work on my phone.
Any help is greatly appreciated.
AT&T's 3G works in the 1900 MHz and 850 MHz frequencies.
Even though HTC Sensation XE is listed as supporting the 850 MHz frequency, it is only using it for slower 2G (EDGE) speeds. For 3G it's using T-Mobile's HSDPA bands 900/1700/2100 MHz. Unfortunately no amount of tweaking in the phone's software will make it work on AT&T's 3G bands, since this is a hardware difference in the phone's modem.
There are very few phones that work on both T-Mobile and AT&T's 3G frequencies - those are called "penta-band". The new Samsung Galaxy Nexus is one of them, along with older Nokia models E7, N8 and N9 phones, for example.