While doing a bit of background research on the amount of wireless spectrum available and used in the US today (more on that in a future post) I had a closer look at the AWS band. The AWS band is mostly used in North America today and encompasses a bandwidth of 45 MHz in the 1700 MHz frequency range for uplink transmission and another 45 MHz for downlink transmission in the 2100 MHz range.
Here's a link that shows who owns how much of that spectrum in the US. T-Mobile US seems to be the only active user today for its UMTS services but pretty much every one else including Verizon and I suppose AT&T (through Cingular) have a chunk as well and might use it in the future for UMTS or LTE services.
But like T-Mobile US, whoever starts using that band will require specific devices supporting that band. For T-Mobile US things have improved a bit in the last year or so with quite a few devices supporting the band now, including all new Symbian3 devices that are even pentaband UMTS capable, i.e. supporting all three US bands and the two major bands used in the rest of the world.
So in other words, most parts of the AWS band is still unused in the US at the moment.