Here is the current
WAAS coverage. Unless more SATs come online, AUS isnt covered.
There were 4 SATs online, but one went down, so the US shifted one over so they would have coverage. (you need 3 for LPV)
There are 2 ground monitoring stations required. Currently, these are located on each Coast of the US.
Each aircraft would then have to have a WAAS capable receiver.