  In this paper, we investigate the propagation coupling loss (captures all
sources of attenuation between serving cell and mobile station (MS)) and
geometry metric (GM) (downlink average signal-to-interference plus noise ratio)
performance of mmWave cellular networks for outdoor and indoor MSs, considering
urban micro (UMi) environments. Based on these studies, we identify effective
mmWave frequency bands for cellular communication. We consider 3GPP compliant
system-level simulations with two power allocation schemes: 1) transmit power
scaled with communication bandwidth, and 2) constant total transmit power.
Simulation results show that with scaled transmit power allocation, GM
performance degradation is small: 20% of MSs experience GM less than 0 dB at
all mmWave frequencies considered, for outdoor MSs. With constant Tx power
allocation, 20% of MSs experience GM less than 0 dB for frequencies up to 30
GHz. Furthermore, 35% (48%) of outdoor MSs experience GM performance less than
0 dB at 60 GHz (100 GHz). On the other hand, for indoor MSs, even with scaled
Tx power allocation, favorable GM performance is observed only at low
frequencies, i.e., 2 GHz.
