GF - OneSky or Civil-Military ATS (CMATS) was needed because the civil, so-called TAAATS, system was a Thales Eurocat system which while being kept up to date in software needed new hardware. We are upgrading to the Thales Eurocat in use in Singapore and other places around the world. The military reason was that the ADF rejected the civil system when it was installed and bought their own. I believe it did not work as advertised and of course, did not"talk" to the civil system. CMATS is supposed to be the common system we should have had 30 years ago!