According to this:
"Verizon and AT&T both run their LTE networks in the 700-MHz band. But Verizon's network is mostly in 746-787MHz, while AT&T's will be primarily in 704-746MHz."
The gross frequency is nice in that it reduces the cell density requirements, but the fine details of upper vs. lower band are negligible and a higher frequency just needs a different RF design to meet the same coverage needs.
My hope is that the global LTE spectrum fragmentation will encourage the use of software tuneable antennas rather than having a bunch of different parts for individual carriers - but that's a while off.