The long awaited FAA ADSB standards for 2020 are released as a Final Rule.
As anticipated it is a "Dogs Breakfast" of conflicting technologies.
The requirement to carry a transponder will remain in perpetuity as a back up for potential system failure if the GPS system goes down for any reason.
The FAA ADSB system is unique and not based on International standards, in fact it is not compatible with either Mexican or Canadian standards their next door neighbours.
The U.S. system will have 2 transmission modes, 1090 Es and UAT.
This means that even if equipped for ADSB in all aircraft won't be able to see all other aircraft unless they carry both 1090Es and UAT, the system has dual architecture.
And there is no subsidy for underwriting any part of the required installation in Aircraft.
There are also no exemptions, so even LSA need to be ADSB out equipped, given the dual architecture a fully equipped LSA might just make it under the 600 kg limit if it doesn't carry fuel.
And now we also know that an STC will be needed to fit the ADSB out the cost will be steep.
Can CASA make a better job of this ?? and what will compatible gear cost given the mess in the largest market in the world, no wonder AOPA USA were vehemently opposed to the rule when it was first propsed.