  What will it take for drones -- and the whole associated ecosystem -- to take
off? Arguably, infallible command and control (C&C) channels for safe and
autonomous flying, and high-throughput links for multi-purpose live video
streaming. And indeed, meeting these aspirations may entail a full cellular
support, provided through 5G-and-beyond hardware and software upgrades by both
mobile operators and manufacturers of these unmanned aerial vehicles (UAVs). In
this article, we vouch for massive MIMO as the key building block to realize
5G-connected UAVs. Through the sheer evidence of 3GPP-compliant simulations, we
demonstrate how massive MIMO can be enhanced by complementary network-based and
UAV-based solutions, resulting in consistent UAV C&C support, large UAV uplink
data rates, and harmonious coexistence with legacy ground users.
