Speeding up the solution of the Site and Power Assignment Problem in Wireless Networks

This paper addresses the site and power assignment problem arising in the optimal design of wireless networks. It is well-known that natural formulations of this problem are sources of numerical instabilities and make the optimal solution challenging for state-of-the-art solvers, even in small-sized instances. We tackle this limitation from a computational perspective by suggesting two implementation procedures that can speed up the solution of this problem. The first is an extremely effective branching rule for a compact reformulation of this problem. Presolve operations are used as a second strategy to manage numerical instability. The approaches are validated using realistic LTE instances kindly provided by Fondazione Ugo Bordoni. The proposed implementation techniques have proved capable of significantly accelerating the solution of the problem, beating the performance of a standard solution.