NOBODY in the world uses this, and no 3G phones (except a rumored one from T-Mobile USA) support it. Also, 1700MHz still has some USA gov't/military still using it, and they get to stay around for another 10 years counting from 2006, or so.
I'm assuming it is the RTR6285 because the Kaiser supports UMTS 2100 (RTR6275/RFR6525, RTR6285), UMTS 1900+850 (RTR6275/RFR6500, RTR6285), and UMTS 2100 + 800 (RTR6275/RFR6525, RTR6285).
The only one that seems to cross all of these bands together is the RTR6285 which also supports 2100 + 1700 + 800MHz (AWS except for the 800), and triple-band receive ability. There's also this Qualcomm PR about AWS support.
Couple that with Kaiser rumors of a T-Mobile USA debut soon ... Maybe the Kaiser won't be obsolete 2008 before WiMaxx/4G/LTE now.