  Using drones as flying base stations is a promising approach to enhance the
network coverage and area capacity by moving supply towards demand when
required. However deployment of such base stations can face some restrictions
that need to be considered. One of the limitations in drone base stations
(drone-BSs) deployment is the availability of reliable wireless backhaul link.
This paper investigates how different types of wireless backhaul offering
various data rates would affect the number of served users. Two approaches,
namely, network-centric and user-centric, are introduced and the optimal 3D
backhaul-aware placement of a drone-BS is found for each approach. To this end,
the total number of served users and sum-rates are maximized in the
network-centric and user-centric frameworks, respectively. Moreover, as it is
preferred to decrease drone-BS movements to save more on battery and increase
flight time and to reduce the channel variations, the robustness of the network
is examined as how sensitive it is with respect to the users displacements.
