I. Introduction
The millimeter-Wave (mmWave) frequency band has been exploited heavily to meet with the rapidly increasing demands on wireless capacity [1]. In mmWave networks, Base Stations (BSs) use multiple highly directional beams to serve the User Equipments (UEs). When each beam is used to transmit data, the mmWave networks can offer high spectral efficiency, being able to serve many UEs in a dense area. However, due to the high-frequency band, mmWave links can be easily affected by blockages, degrading the data rate significantly. To mitigate the impact of blockages and because of the small size of cells, mmWave BSs should be densely deployed in reality.