  Gate holding reduces congestion by reducing the number of aircraft present on
the airport surface at any time, while not starving the runway. Because some
departing flights are held at gates, there is a possibility that arriving
flights cannot access the gates and have to wait until the gates are cleared.
This is called a gate conflict. Robust gate assignment is an assignment that
minimizes gate conflicts by assigning gates to aircraft to maximize the time
gap between two consecutive flights at the same gate; it makes gate assignment
robust, but passengers may walk longer to transfer flights. In order to
simulate the airport departure process, a queuing model is introduced. The
model is calibrated and validated with actual data from New York La Guardia
Airport (LGA) and a U.S. hub airport. Then, the model simulates the airport
departure process with the current gate assignment and a robust gate assignment
to assess the impact of gate assignment on gate-holding departure control. The
results show that the robust gate assignment reduces the number of gate
conflicts caused by gate holding compared to the current gate assignment.
Therefore, robust gate assignment can be combined with gate-holding departure
control to improve operations at congested airports with limited gate
resources.
