Annotated United States 902-928Mhz ISM Band Rules

47 CFR § 15.247 Operation within the bands 902–928 MHz, 2400–2483.5 MHz, and 5725–5850 MHz.

With regard to frequency hopping:

  • Shall have hopping channel carrier frequencies separated by a minimum of 25 kHz or the 20 dB bandwidth of the hopping channel, whichever is greater.
  • Shall hop to channel frequencies that are selected from a pseudo randomly ordered list of hopping frequencies.
  • Each frequency must be used equally on the average by each transmitter.
  • If the 20 dB bandwidth of the hopping channel is less than 250 kHz, use at least 50 hopping frequencies with an average time of occupancy on any frequency not greater than 0.4 seconds within a 20 second period.
  • If the 20 dB bandwidth of the hopping channel is 250 kHz or greater, use at least 25 hopping frequencies with an average time of occupancy on any frequency not greater than 0.4 seconds within a 10 second period.
  • The maximum allowed 20 dB bandwidth of the hopping channel is 500 kHz.