  In this paper, we discuss resource sharing, a key dimension in mmWave network
design in which spectrum, access and/or network infrastructure resources can be
shared by multiple operators. It is argued that this sharing paradigm will be
essential to fully exploit the tremendous amounts of bandwidth and the large
number of antenna degrees of freedom available in these bands, and to provide
statistical multiplexing to accommodate the highly variable nature of the
traffic. In this paper, we investigate and compare various sharing
configurations in order to capture the enhanced potential of mmWave
communications. Our results reflect both the technical and the economical
aspects of the various sharing paradigms. We deliver a number of key insights,
corroborated by detailed simulations, which include an analysis of the effects
of the distinctive propagation characteristics of the mmWave channel, along
with a rigorous multi-antenna characterization. Key findings of this study
include (i) the strong dependence of the comparative results on channel
propagation and antenna characteristics, and therefore the need to accurately
model them, and (ii) the desirability of a full spectrum and infrastructure
sharing configuration, which may result in increased user rate as well as in
economical advantages for both service provider.
