We're seven months to the FAA's ADS-B Out mandate but the ground is already shifting with a planned move from a ground-based to a satellite-based system. So-called space-based ADS-B (SBA) would help fill in coverage areas currently beyond the reach of land-based data transceivers.
This is a companion discussion topic for the original entry at https://www.avweb.com/avionics/satellite-ads-b-progressing