ORDER
Adopted: August 27, 2020 Released: August 27, 2020
By the Deputy Chief, Mobility Division, Wireless Telecommunications Bureau:
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Introduction. We have before us a request filed by the American Radio Relay League (ARRL) for a temporary waiver to permit amateur data transmissions at a higher symbol rate than currently is permitted by section 97.307(f) of the Commission’s rules, in order to facilitate hurricane relief communications within the continental United States.1 For the reasons set forth below, we grant the waiver request.
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Background. Section 97.307(f) limits the symbol rate (also known as the baud rate) – the rate at which the carrier waveform amplitude, frequency, and/or phase is varied to transmit information2 – for high frequency (HF) amateur radioteletype (RTTY)/data transmissions as follows to 300 bauds for frequencies below 28 MHz (except the 60 meter band), and 1200 bauds in the 10 meter (28-29.7 MHz) band.3 The digital code used to encode the signal being transmitted must be one of the codes specified in section 97.309(a) of the Commission’s rules, but an amateur station transmitting a RTTY or data emission using one of the specified digital codes may use any technique whose technical characteristics have been publicly documented, such as CLOVER, G-TOR, or PACTOR.4
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In 2016, in response to an ARRL petition for rulemaking, the Commission proposed to remove the symbol rate limitations, which it tentatively concluded had become unnecessary due to advances in modulation techniques and no longer served a useful purpose.5 That proceeding is currently pending.