It's not rocket science. The ADSB design/protocols are designed to ignore corrupted messages. So all it needs it needs is a series of receivers and a database system that removes duplicates (trivial).
Better yet, use multiple designs fro multiple manufacturers in order to avoid any sort of systemic issue in the software design.
Heck, mandate every NBN wireless tower to have 3 from 3 different manufacturers. Bandwidth is already there.
It's an absolute joke that NBN isn't used for this low bandwidth application.