Ratboy, FANS trials in the Pacific are not ADS-B at all . I am not sure the Alaska trials will also be pure ADS-B.
I think people confuse pure ADS , which is when the ground interrogates the aircraft systems to determine a position, and in case of FANS-1 it uses the ACARS data link to do this )and display this position on a data display on the ground for controllers. On the contrary, ADS-B is the a/c systems BROADCASTING their position to each other, and this info displayed on a samll data screen in the cockpit.