Sec.  2.944   Software defined radios.

   (a) Manufacturers must take steps to ensure that only software that has been
   approved with a software defined radio can be loaded into the radio. The
   software must not allow the user to operate the transmitter with operating
   frequencies,  output  power, modulation types or other radio frequency
   parameters outside those that were approved. Manufacturers may use means
   including, but not limited to the use of a private network that allows only
   authenticated users to download software, electronic signatures in software
   or  coding  in hardware that is decoded by software to verify that new
   software can be legally loaded into a device to meet these requirements and
   must describe the methods in their application for equipment authorization.

   (b) Any radio in which the software is designed or expected to be modified
   by  a party other than the manufacturer and would affect the operating
   parameters of frequency range, modulation type or maximum output power
   (either  radiated  or conducted), or the circumstances under which the
   transmitter operates in accordance with Commission rules, must comply with
   the requirements in paragraph (a) of this section and must be certified as a
   software defined radio.

   (c) Applications for certification of software defined radios must include a
   high level operational description or flow diagram of the software that
   controls the radio frequency operating parameters.

   [ 70 FR 23039 , May 4, 2005]