I think the Aussie system is of French design. Should one inadvertently set the wrong TXPR code on the ground in one's Boeing or Airbus, and that code has been assigned to a Cessna 172 on the other side of the country, the automatic pickup once airborne causes all sorts of problems, because the 172 is now exceeding its design perameters and has mysteriously crossed the country. But one's Boeing or Airbus is still safely on the ground.
