Active Antenna System (AAS)
An active antenna system integrates the radio electronics into the antenna itself, with an array of elements each driven by its own transceiver.
What is Active Antenna System (AAS)?
AAS enables beamforming and massive MIMO. Vendors call the integrated unit an active antenna unit or active array unit (AAU). Because there is no antenna connector, 3GPP specifies over-the-air test requirements for AAS base stations.