Sec.  18.111   General operating conditions.

   (a) Persons operating ISM equipment shall not be deemed to have any vested
   or recognizable right to the continued use of any given frequency, by virtue
   of any prior equipment authorization and/or compliance with the applicable
   rules.

   (b) Subject to the exceptions in paragraphs (c) and (d) of this section and
   irrespective of whether the equipment otherwise complies with the rules in
   this part, the operator of ISM equipment that causes harmful interference to
   any authorized radio service shall promptly take whatever steps may be
   necessary to eliminate the interference.

   (c) The provisions of paragraph (b) of this section shall not apply in the
   case of interference to an authorized radio station or a radiocommunication
   device operating in an ISM frequency band.

   (d) The provisions of paragraph (b) of this section shall not apply in the
   case  of  interference  to a receiver arising from direct intermediate
   frequency pickup by the receiver of the fundamental frequency emissions of
   ISM equipment operating in an ISM frequency band and otherwise complying
   with the requirements of this part.