I suggest a space traffic control system, similar to our current air traffic control system. ATCs generally keep control of their own airspace, but there are cooperation agreements between countries for both border crossings and areas without national borders. Planes fly at altitudes and along set routes that are assigned by the controllers.

Something similar could easily be done in space, but it would be a UN function because no country owns territory in space. But satellites could be assigned certain altitudes, perhaps a certain altitude range could be "owned" by particular countries or groups of countries. Many if not most satellites are in stationary orbit, so their locations can be documented and computers could monitor that location for potential trouble.