  We propose using Carrier Sensing (CS) for distributed interference management
in millimeter-wave (mmWave) cellular networks where spectrum is shared by
multiple operators that do not coordinate among themselves. In addition, even
the base station sites can be shared by the operators. We describe important
challenges in using traditional CS in this setting and propose enhanced CS
protocols to address these challenges. Using stochastic geometry, we develop a
general framework for downlink coverage probability analysis of our shared
mmWave network in the presence of CS and derive the downlink coverage
probability expressions for several CS protocols. To the best of our knowledge,
our work is the first to investigate and analyze (using stochastic geometry) CS
for mmWave networks with spectrum and BS sites shared among non-coordinating
operators. We evaluate the downlink coverage probability of our shared mmWave
network using simulations as well as numerical examples based on our analysis.
Our evaluations show that our proposed enhancements lead to an improvement in
downlink coverage probability, compared to the downlink coverage probability
with no CS, for higher values of signal-to-interference and noise ratio (SINR).
Interestingly, our evaluations also reveal that for lower values of SINR, not
using any CS is the best strategy in terms of the downlink coverage
probability.
