I know that t-mobile USA uses different 3g frequencies than ATT (will edit post later to put in details if u post the differences in frequencies)

However, my question is, why wouldn't one be able to theoretically write code that forces the antena to pick up a different frequency in the 3gs?

Obviously I don't know how this works, but I'm sure someone out there can explain it well.

Has anyone torn apart an iPhone 3gs to see what is inside yet?

You aren't just able to "tell" an antenna to use another frequency...

Antennas are a length of wire of a certain length to allow for it to resonate with a particular frequency.
These antennas can operate over multiple frequencies *if* the other frequency is a harmonic of your base frequency.

T-Mobile uses 1700MHz and 2100 MHz for their 3g network.
AT&T uses 1900MHz, as do the other 3G networks around the world.

While it is *possible* that the antenna will have harmonics visible in both the 1700MHz and 2100MHz band, it is unlikely that one would be able to receive any significant amperage or broadcast across that frequency.

Someone would need to do some tests to see whether this is viable, however from a technical perspective, it is *very* unlikely that you would end up with any meaningful coverage area using the iPhone 3GS on T-Mobile's 3G network.

~Adrian

they are using diffeernt hardwares freq.

never possible.

thats why its pointless and stupid if you ever use an iphone 3g network for TMOBILE its fucking slow.

the downside of ATT is the cost. but faster speed than tmobile 3g obviously.

not sure about now but i believe that they are tuned with crystals to recieve certain frequency and that it would be a hardware modification could be completely wrong and maybe it is a vid adjusting voltage to change oscilation to adjust resonant frequence or jsut completley dif technology just my guess. otherwise their would be no point in dif hardware for tri quad band

One problem with that statement, this USB 3G device sold by T-Mobile USA has the exact frequencies as the iphone 3g, unless its not accurate information

T-Mobile webconnect USB

It has 2100, and in the US TMobile uses 1700 and 2100 iirc.

tmo usb device
Band (frequency): 850 MHz;900 MHz;1800 MHz;1900 MHz;UMTS: Band IV (AWS);2100

iphone 3g(s)
UMTS/HSDPA (850, 1900, 2100 MHz)
GSM/EDGE (850, 900, 1800, 1900 MHz)

I dont understand-
If you say that the tmobile 3g frequency is 1700 and 2100 and the ATT is 2100 why can we not run the 2100 band iirc on an unlocked iphone for tmo?

OR is the latter post which says ATT only uses 1900 freq the correct answer?

ATT uses Band II (1900 MHz) or Band V (850 MHz), T-mobile uses Band IV AWS (part lower part of 1700 MHz and lower part of 2100 MHz), it will never be compatible. The 2100 MHz band the iphone uses is Band I.

Cell receptions are achieved by calibrating the resonant crystal, which is done on hardware level, so software override is not possible