AIM DECODED

4-5-10. Automatic Dependent Surveillance-Rebroadcast (ADS-R)

AIM Text

  1. Introduction.

    ADS-R is a datalink translation function of the ADS-B ground system required to accommodate the two separate operating frequencies (978 MHz and 1090 ES). The ADS-B system receives the ADS-B messages transmitted on one frequency and ADS-R translates and reformats the information for rebroadcast and use on the other frequency. This allows ADS-B In equipped aircraft to see nearby ADS-B Out traffic regardless of the operating link of the other aircraft. Aircraft operating on the same ADS-B frequency exchange information directly and do not require the ADS-R translation function. (See FIG 4-5-7 and FIG 4-5-8.)

  2. Reports of ADS-R Malfunctions.

    Users of ADS–R can provide valuable assistance in the correction of malfunctions by reporting instances of undesirable system performance. Since ADS–R performance is monitored by maintenance personnel rather than ATC, report malfunctions to the nearest Flight Service Station (FSS) facility by radio or telephone, or by sending an email to the ADS-B help desk at adsb@faa.gov. Reports should include:

    1. Condition observed;
    2. Date and time of observation;
    3. Altitude and location of observation;
    4. Type and call sign of the aircraft and;
    5. Type and software version of avionics system.

Source: FAA Aeronautical Information Manual · current edition · paragraph 4-5-10.

Research Notes

AIM 4-5-10 covers Traffic Information Service (TIS) — the older ground-based traffic broadcast that has largely been superseded by TIS-B (the ADS-B equivalent).

What TIS provided: Real-time traffic information broadcast from ground-based interrogators to TIS-equipped aircraft. Predecessor to ADS-B TIS-B.

Status: Legacy system, no longer maintained. Aircraft still equipped with TIS receivers have been migrating to ADS-B In for traffic data.

Reference: AIM 4-5-10; AIM 4-5-6 (ADS-B).