Sec.  25.273   Duties regarding space communications transmissions.

   (a) No person shall:

   (1)  Transmit to a satellite unless the specific transmission is first
   authorized by the satellite network control center;

   (2)  Conduct  transmissions  over a transponder unless the operator is
   authorized by the satellite licensee or the satellite licensee's successor
   in interest to transmit at that time; or

   (3) Transmit in any manner that causes unacceptable interference to the
   authorized transmission of another licensee.

   (b) Satellite operators shall provide upon request by the Commission and by
   earth station licensees authorized to transmit on their satellites relevant
   information  needed to avoid unacceptable interference to other users,
   including  the  polarization angles for proper illumination of a given
   transponder.

   (c) Space station licensees are responsible for maintaining complete and
   accurate technical details of current and planned transmissions over their
   satellites, and shall require that authorized users of transponders on their
   satellites, whether by tariff or contract, provide any necessary technical
   information in this regard including that required by  Sec. 25.272. Based on this
   information, space station licensees shall exchange among themselves general
   technical information concerning current and planned transmission parameters
   as  needed  to  identify  and  promptly resolve any potential cases of
   unacceptable interference between their satellite systems.

   (d) Space stations authorized after May 10, 1993 which do not satisfy the
   requirements of  Sec. 25.210 may be required to accept greater constraints in
   resolving interference problems than complying ones. The extent of these
   constraints shall be determined on a case-by-case basis.