  6G and beyond networks will merge communication and computation capabilities
in order to adapt to changes. As they will consist of many sensors gathering
information from its environment, new schemes for managing these large amounts
of data are needed. For this purpose, we review Over the Air (OTA) computing in
the context of estimation and detection. For distributed scenarios, such as a
Wireless Sensor Network, it has been proven that a separation theorem does not
necessarily hold, whereas analog schemes may outperform digital designs. We
outline existing gaps in the literature, evincing that current state of the art
requires a theoretical framework based on analog and hybrid digital-analog
schemes that will boost the evolution of OTA computing. Furthermore, we
motivate the development of 3D networks based on OTA schemes, where satellites
function as sensors. We discuss its integration within the satellite segment,
delineate current challenges and present a variety of use cases that benefit
from OTA computing in 3D networks.
