An FCC order today clarified the rules that govern software-defined radios (SDRs) and cognitive radios.

In FCC-speak, an SDR is a radio whose regulated characteristics (such as frequency range, bandwidth, modulation, and maximum power) are under software control. The FCC established special procedures in 2001 for lawfully modifying SDRs through software changes. A cognitive radio is one step beyond — an SDR that adjusts its own operating parameters by interacting with the radio-frequency environment. The FCC amended the SDR rules in 2005 to facilitate the development of cognitive radios.

Today the FCC did the following:

  • clarified that an SDR must be certified under the SDR rules only if its software is designed or expected to be modified by parties other than the manufacturer; otherwise (at the manufacturer’s option) can be certified as an ordinary radio;
  • stated as policy that manufacturers should not make public the security software that prevents unauthorized persons from modifying an SDR (which seems obvious to us);
  • declined to adopt a rule requiring confidential treatment of SDR software submitted to the FCC, noting that it expects to request such submissions only infrequently;
  • declined to launch a rulemaking on the separate regulation of digital-to-analog (D/A) converters, despite a party’s assertions that a D/A converter with appropriate software can act like a radio transmitter; and
  • clarified that the rules exempting most amateur radio transmitters from FCC certification remain unchanged, even if the transmitters incorporate SDR capability.

The FCC order may be found at this link.