Originally Posted by
PAX_fips
Pushback is on 'ramp' control at larger airports or also on 'ground'.)
This is one thing I wanted to mention when I posted yesterday but didn't have time.
The ramp control is actually staffed and run by the airline operating within the individual ramp area, not by ATC. It has a similar function to ground control in that it keeps an orderly flow of aircraft inbound to and outbound from the ramp, and coordinates pushback from the gate to prevent multiple aircraft pushing back at the same time and creating gridlock.
If an aircraft is parked at a gate where they must push back directly onto an active taxiway (typically gates at the very ends of a terminal building), the aircraft will get approval from the ATC ground control to occupy the taxiway before they start to push back.