This document provides interoperability requirements to enable
FANS 1/A aircraft and ATN aircraft to co-exist in the same
operational environment.  The standard was developed to enable
air traffic service providers (ATSPs) to interoperate with data
link equipped aircraft, regardless of which technology is
installed on the aircraft.  The standard is intended for the
convergence of oceanic and continental data link applications.
It provides the interoperability requirements for an
aeronautical telecommunication network baseline 1 (ATN B1)
ground system that provides air traffic data link services to
future air navigation system 1/A (FANS 1/A) aircraft in 
continental airspace.