November 18, 1994
                                    
                      Memorandum of Understanding 
                              Between the 
                   Federal Communications Commission, 
      National Telecommunications and Information Administration, 
                                  and 
                     Federal Aviation Administration
                               Addressing 
   Out-of-Band Emission Requirements for the Mobile-Satellite Service 

     The Federal Communications Commission (FCC), National Telecommunications and
Information Administration (NTIA), and Federal Aviation Administration (FAA) have signed
a Memorandum of Understanding (MOU) regarding the initiative to allow commercial mobile
satellite services (MSS) in the United States next year.  The MOU will culminate in technical
standards permitting both MSS systems and a global navigation satellite system (GNSS) to
operate compatibly. 

      MSS systems will provide seamless, voice and data communication services to all
areas of the United States, including remote areas that cannot now receive such services.
GNSS will be composed of the U.S. Global Positioning System (GPS) and the Russian Global
Orbiting Navigation Satellite System (GLONASS).  It will be used by the aviation and
maritime communities to provide enroute navigation, precision approach, landing, and
terminal guidance for aviation users and harbor entry and vessel traffic service navigation for
maritime users.  

     The FCC, NTIA and FAA agreed to cooperate with the aviation, maritime, and MSS
industries to develop and propose national and international standards to foster co-existence
between GPS and GLONASS receivers, and MSS user transceivers.  Under the MOU, RTCA,
Inc. (RTCA) will continue to: develop out-of-band emission standards for MSS user
transmissions to protect GNSS receivers; develop GPS/GLONASS receiver susceptibility
standards;  implement timetables;  and address associated issues.  The FCC, NTIA, and FAA
will then initiate proceedings to consider RTCA's proposals.


                                  (over)

                                   - 2 -

      Until standards are adopted, the FCC, in concurrence with the FAA and NTIA, will
determine on a case-by-case basis whether proposed MSS user transceivers could cause
harmful interference to GPS receivers.  MSS user transceiver licensees will be required to
terminate interfering operations immediately upon notification by the FCC or NTIA of
harmful interference, and to comply with any out-of-band emission standards that are later
incorporated in FCC rules.  The FAA and NTIA agreed not to object to FCC authorization of 
user transceivers for the American Mobile Satellite Corporation (AMSC) MSS system.  This
will allow AMSC to implement mobile-satellite services next year, when its first satellite is
launched.

     The MOU will remain in effect until September 30, 1999.

                                  - FCC -