Remote Electrical Tilt
The Remote Electrical Tilt for short " RET " is a system that enables the electrical tilt of an antenna to be set remotely without touching the antenna. The tilt describes the inclination of the vertical main beam direction of directed antennas.
The system is mainly used in mobile radio systems and serves here to minimize costs and for traffic-dependent coverage settings. With the latter, the aim, especially in UMTS networks, is to adjust to so-called hotspots , depending on the time of day or traffic load , such as large events - but also everyday traffic jams on a motorway - to which the mobile network adjusts itself . Most RET systems use the AISG (Antenna Interface Standards Group) protocol , some use the Ericsson RET protocol, others support both, with 3GPP advocating the AISG protocol and this system will become the norm .