Garmin GDL 88 User Guide - Page 39

TCAS TIS-B UAT XPDR Traffic Collision Avoidance System. An aircraft collision avoidance system designed to reduce the incidence of midair collisions between aircraft. It monitors the airspace around an aircraft for other aircraft equipped with a corresponding active transponder, independent of air traffic control, and warns pilots of the presence of other transponder-equipped aircraft which may present a threat of mid-air collision. Traffic Information Services-Broadcast. TIS-B supplements ADS-B's air-to-air services to provide more situational awareness in the cockpit of all traffic known to the ATC system. The ground TIS-B station transmits surveillance target information on the ADS-B data link for unequipped targets or targets transmitting only on another ADS-B link. TIS-B is a free service available to aircraft operators equipped with ADS-B Out and ADS-B In. Universal Access Transceiver. The GDL 88 UAT transmits ADS-B Out data on the 978 MHz (UAT) frequency. The GDL 88 UAT receives ADS-B, ADS-R, TIS-B, and FIS-B on 978 MHz Transponder. The equipment which broadcasts aircraft code, altitude and other information to ground facilities and other aircraft. 190-01122-03 Rev. A GDL 88 ADS-B Transceiver Pilot's Guide 7-3