  This paper proposes a real-time movement control algorithm for massive
unmanned aerial vehicles (UAVs) that provide emergency cellular connections in
an urban disaster site. While avoiding the inter-UAV collision under temporal
wind dynamics, the proposed algorithm minimizes each UAV's energy consumption
per unit downlink rate. By means of a mean-field game theoretic flocking
approach, the velocity control of each UAV only requires its own location and
channel states. Numerical results validate the performance of the algorithm in
terms of the number of collisions and energy consumption per data rate, under a
realistic 3GPP UAV channel model.
