Prototype ADS-B system in the Midwest: Description and lessons learned

The Federal Aviation Administrations (FAA), in coordination with United Parcel Service (UPS), is developing an air traffic management application called Airline-Based En-Route Sequencing and Spacing (ABESS). The mission of ABESS is to enable airlines to adjust the spacing of aircraft arriving at an en-route merge fix by up-linking speed advisories during the en-route flight phase.