ADS-B is one of the most important, underlying technologies in the FAA’s plan to transform air traffic control from the current radar-based system ( that was invented during World War II) to a satellite-based system. ADS-B is bringing the precision and reliability of satellite-based surveillance to the nation’s skies.
AviationGlossary.com defines ADS-B as Automatic Dependent Surveillance Broadcast ADS-B is a next generation surveillance technology incorporating both air and ground aspects that provide air traffic control (ATC) with a more accurate picture of the aircraft’s three-dimensional position in the en route, terminal, approach and surface environments. The aircraft provides the …show more content…
Under the proposal, operators would equip their aircraft with avionics based on the airspace in which they plan to operate. The FAA is currently reviewing comments and will issue a final rule soon. The final rule will specify performance standards for ADS-B avionics. The marketplace will then take over, as manufacturers build avionics that must meet those standards. 
What about ADS-B installations?
In United States, the FAA expects by 2010 to be able to “commission” ADS-B services for use in the national airspace system, and by 2013 to have coverage everywhere there is now radar coverage. The full evolution of ADS-B will take about 20years, taken in manageable segments of equipage and ground-station installation, with about half of the legacy radars maintained throughout to provide a back-up in case of a GPS outage. Benefits in improved safety and efficiency will accrue with each step of the implementation. 
In Europe, the European Commission (EC) has issued a notice of proposed rulemaking (NPRM) announcing its intent to mandate carriage of automatic dependent surveillance-broadcast (ADS-B) transponders by 2015, versus the FAA’s planned 2020 deadline. The EC also calls for its 27 member nations to align their ATC procedures more closely with those of their neighbors to create a seamless European airspace system that supports five- and three-mile separation standards, for en route and terminal operations, respectively. These initiatives are