  Unmanned aerial vehicles (UAVs) can be used as aerial wireless base stations
when cellular networks go down. Prior studies on UAV-based wireless coverage
typically consider an Air-to-Ground path loss model, which assumes that the
users are outdoor and they are located on a 2D plane. In this paper, we propose
using a single UAV to provide wireless coverage for indoor users inside a
high-rise building under disaster situations (such as earthquakes or floods),
when cellular networks are down. First, we present a realistic Outdoor-Indoor
path loss model and describe the tradeoff introduced by this model. Then, we
study the problem of efficient UAV placement, where the objective is to
minimize the total transmit power required to cover the entire high-rise
building. The formulated problem is non-convex and is generally difficult to
solve. To that end, we consider two cases of practical interest and provide the
efficient solutions to the formulated problem under these cases. In the first
case, we aim to find the minimum transmit power such that an indoor user with
the maximum path loss can be covered. In the second case, we assume that the
locations of indoor users are symmetric across the dimensions of each floor.
