Register Account

Login Help


ARRL Renews Request for FCC to Replace Symbol Rate with Bandwidth Limit


In ex parte comments filed on September 17 in WT Docket 16-239, ARRL renewed its request that the FCC delete symbol-rate limits for data transmissions in the Amateur Service rules. As it did in its initial filing, ARRL asked the FCC to couple the removal of the symbol rate limits with the adoption of a 2.8 kHz bandwidth limit. In response to a 2013 ARRL Petition for Rulemaking (RM-11708), the FCC proposed deleting the symbol-rate limits but declined to replace them with the 2.8 kHz bandwidth that ARRL wanted.

“This proceeding addresses an update to the Commission’s rules that is needed because a limitation in the rules unintentionally is inhibiting US amateurs from employing the latest improvements to some of the digital modes,” ARRL said in its remarks. “Data signals commonly used for daily communications as well as in disaster situations have bandwidths in the range of 2.5 kHz and must co-exist with other modes that use bandwidths as narrow as 50 Hz.”

ARRL said the 1980s-era symbol-rate limits now inhibit the use of some efficient data modes. “The symbol rate limit uniquely prevents radio Amateurs in the United States from experimenting and innovating with a class of modern digital communication techniques that already are widely used in other countries,” ARRL told the FCC. “The limit also impairs the ability of Amateurs to improve support that they offer in times of disaster.”

Repealing the symbol-rate limit would “allow shortened transmission times for the same amount of data without increasing the bandwidth occupied by the signal,” ARRL contended. “Other Amateurs would benefit by the resulting reduction in potential interference.”

ARRL’s remarks also addressed issues raised by other parties. “Discussion by commenters in this proceeding delve into subjects well beyond its scope,” ARRL said, noting that it had attempted to broker consensus among “some of the most active commenters” with an eye toward exploring possible areas of agreement for the FCC’s consideration. ARRL noted that the parties to the ARRL-arranged talks declined to forward to the FCC “joint recommendations on which conditional agreement had been reached.”

“The issues discussed with the parties are outside the scope of this Docket and would require a further Notice of Proposed Rulemaking before final consideration,” ARRL observed. “Some of the same issues also are raised in petitions for rulemaking on which the Commission has sought comment. Given the policy as well as factual disagreements evidenced in the record, we understand that the Commission may decide to consider some of these issues.”

One of those issues involves automatically controlled digital stations (ACDS). Commenters’ concerns focused on interference that could occur with a move away from symbol-rate criteria. ACDS with signals wider than 500 Hz and below 29.7 MHz are confined to specific subbands. ARRL recommended that the FCC consider rule changes that would have all ACDS stations and digital stations with bandwidths greater than 500 Hz share identified subbands.

ARRL said if additional signals are added to the ACDS subbands, as recommended, that it would strongly support expanding the HF ACDS subbands. But, ARRL added, “changing the subband boundaries requires study and careful consideration of trade-offs, because any changes will affect multiple user interests.” ARRL referred subband reformulation issues to its HF Band Planning Committee for study and recommendations.

Some commenters also raised the issue of obscure and encrypted messages. ARRL pointed out in its ex parte remarks that it remains opposed to encryption in the amateur bands, but disagreed “with commenters who argue that the digital modes being used by radio amateurs around the world are per se ‘obscured’ or ‘encrypted.’”

ARRL noted that FCC rules permit the use of “new and innovative digital modes” without prior approval, if specified conditions are met. Digital techniques must use approved codes with publicly documented technical characteristics, and their purpose must be to facilitate communication and not to obscure content.

“Some commenters allege that specific messages violate the Commission’s rules governing encryption, third-party messages, pecuniary interests, objectionable language, or commercial carriage,” ARRL noted, and they have called for open-source decoding software to aid in enforcing the applicable rules. “We observe that recently there have been laudable efforts at self-policing,” ARRL said. “Unresolved complaints are appropriately handled as enforcement matters rather than as rulemaking matters.”

ARRL concluded, “It is vital that the rules governing the Amateur Radio Service facilitate continuation of its experimental traditions and purposes. Using the Amateur spectrum ‘sandbox’ for innovation and development of new ideas and technologies is of significant public benefit.”



Instragram     Facebook     Twitter     YouTube     LinkedIn