Proposed rule change would update 1980 provisions that limit radio-transmitted data rates.
The amateur radio community has come a long way since the early days of Morse code (even though, as recently as 2006, many amateurs opposed the FCC’s dropping a Morse code requirement). In fact Morse was the first popular form of digital radio transmission. But it was slow. Most amateurs, for most of the last century, preferred voice. Starting around the middle of the century, with the FCC’s blessing, a few amateurs began connecting Teletype machines to their transmitters, sending text messages via warbling tones that used a clumsy 5-bit protocol called a Baudot code. In 1980, after many amateurs had acquired early versions of the “home computers” that used the more modern 8-bit ASCII code, the FCC adjusted the rules to allow ASCII transmissions as well.
But the 1980 rules indirectly limited the speed of data transmission in some of the amateur bands most used for long-distance communications, those below about 30 MHz. Not that the FCC cared how fast anyone sent data way back then. But the accepted wisdom, in those days, said that higher data speeds necessarily occupied higher bandwidths – i.e., took up more spectrum. The FCC’s caps on “symbol rates,” which are one factor in data rates, supposedly furthered the goal of limiting how much spectrum any one transmission used.
During the intervening 33 years, as data transmission by radio matured from a curiosity to a necessity (smartphones, digital TV, Wi-Fi, etc.), engineers got much better at packing higher data rates into lower bandwidths. Notwithstanding this progress, however, the increasingly anachronistic symbol-rate limits remained in the FCC’s amateur rules.
The organization “ARRL, the national association for Amateur Radio” (originally, the American Radio Relay League) has now filed a Petition for Rulemaking that asks the FCC to fix the anomalies. ARRL’s proposal is simple: eliminate the caps on symbol rates, and instead regulate the element that actually matters – by imposing specific, numerical limits on bandwidth.
We think the idea has a lot of merit. Perhaps most important, it would free amateurs to experiment with faster modes of data transmission while still maximizing their sharing of scarce long-range spectrum resources.
The ARRL petition was filed on November 15, but the FCC has already given it a file number and invited preliminary comments on it. Tell the FCC what you think: file via ECFS in proceeding RM-11708, by December 23, 2013.