New Formulations for Optimal User Coverage using 5G Millimeter-Wave-based Networks

In this paper, we consider two optimization problems related to 5G millimeter wave (mmWave) networks. The first one consists of maximizing the number of covered users using a predefined number of base stations (BSs) while simultaneously minimizing the distances between users and BSs. Whereas the second one minimizes the total number of BSs required to cover all users in the network. Notice that mmWave technology has been conceived in the literature as one of the most promising techniques for 5G networks. However, there are still several issues to be addressed before this technology can be used massively in real-life networks. For example, mmWaves cannot penetrate walls easily and their path loss is high which reduces the transmission distances. We propose mixed-integer programming models to deal with these problems. Our models can solve instances with up to 100 BSs and 1000 users optimally. Our numerical results indicate that minimizing the distances between users and BSs and maximizing user coverage simultaneously leads to instances that are significantly harder to solve. Finally, we report the minimum number of BSs required to cover all users in the network together with the minimum radius that makes it possible.