  In this paper, we propose a novel wireless scheme that integrates satellite,
airborne, and terrestrial networks aiming to support ground users. More
specifically, we study the enhancement of the achievable users' throughput
assisted with terrestrial base stations, high altitude platforms (HAPs), and
satellite station. The goal is to optimize the resource allocations and the
HAPs locations in order to maximize the users' throughput. In this context, we
propose to solve the optimization problem in two stages; first a short-term
stage and then a long-term stage. In the short-term stage, we start by
proposing a near optimal solution and low complexity solution to solve the
associations and power allocations. In the first solution, we formulate and
solve a binary linear optimization problem to find the best associations and
then using Taylor expansion approximation to optimally determine the power
allocations. While in the second solution, we propose a low complexity approach
based on frequency partitioning technique to solve the associations and power
allocations. One the other hand, in the long-term stage, we optimize the
locations of the HAPs by proposing an efficient algorithm based on a recursive
shrink-and-realign process. Finally, selected numerical results show the
advantages provided by our proposed optimization scheme.
