Back when I did my Qualcomm modems and transceivers piece, I gained a deeper understanding about the cellular RF engineering side of the handset puzzle. Specifically, how an OEM can enable LTE on some bands and not enable WCDMA on those very same bands. The interesting and relevant takeaway from the whole exploration is that all ports on the transceiver are created equal, and that if an OEM implements LTE on a particular band, that usually means that the device design can inherit support for 3G WCDMA on that same band, given the right power amplifier. I alluded at the end of the article to the fact that if you see an OEM implement band 4 on LTE and not band 4 on WCDMA...
Why the iPhone 5 Lacks Support for Simultaneous Voice and LTE or EVDO (SVLTE, SVDO)
So we've seen the new iPhone, and had a chance to briefly play with it at the demo room, but as I've learned in the past so many times...90 by Brian Klug on 9/14/2012