  The integration of sensing capability in the design of wireless communication
systems is foreseen as a key enabler for efficient radio resource management in
next-generation networks. This paper focuses on millimeter-wave communications,
which are subject to severe attenuation due to blockages, ultimately
detrimental to system performance. In this context, the sensing functionality
can allow measuring or even imaging the wireless environment allowing
anticipation of possible link failures, thus enabling proactive resource
reallocation such as handover. This work proposes a novel mechanism for
opportunistic environment sensing, which leverages existing network
infrastructure with low complexity. More specifically, our approach exploits
the fluctuations of interference, perceived in antenna side lobes, to detect
local activity due to a moving blocker around the reference communication link.
Numerical evaluations show that the proposed method is promising as it allows
effective assessment of the blocker direction, trajectory and possibly, its
location, speed, and size.
