  Unmanned aerial vehicles (UAVs) and communication systems are fundamental
elements in Mission Critical services, such as search and rescue. In this
article, we introduce an architecture for managing and orchestrating 5G and
beyond networks that operate over a heterogeneous infrastructure with UAVs'
aid. UAVs are used for collecting and processing data, as well as improving
communications. The proposed System Intelligence (SI) architecture was designed
to comply with recent standardization works, especially the ETSI Experiential
Networked Intelligence specifications. Another contribution of this article is
an evaluation using a testbed based on a virtualized non-standalone 5G core and
a 4G Radio Access Network (RAN) implemented with open-source software. The
experimental results indicate, for instance, that SI can substantially improve
the latency of UAV-based services by splitting deep neural networks between UAV
and edge or cloud equipment. Other experiments explore the slicing of RAN
resources and efficient placement of virtual network functions to assess the
benefits of incorporating intelligence in UAV-based mission-critical services.
