atcea
What you suggest sounds very much (if not identical) to the Free Flight trials I had some involvement in (as a Controller Guinea Pig) at the ATC research centre in Amsterdam. This was being conducted on behalf of NASA about 8 years ago.
They actually had a model of Eurocontrol airspace with about 300 aircraft flying through it all separated by a TCAS type device and all on their own navigation. Looked great, although I wondered what would happen if the TCAS on 1 aircraft failed? ;-)
Last I heard the US were going to trial it in Alaskan & Hawain airspace but there were problems. Not least over funding of the kit required in all the aircraft!
BD