In the wake of recent changes in the Part 97 Amateur Radio rules, the ARRL has revised its “regulation by bandwidth” proposals to match the new reality, avoid some unintended consequences and temper some of the controversy the original petition had aroused. In a November 2005 Petition for Rule Making (RM-11306 http://www.arrl.org/announce/regulatory/rm-11306/RM-11306-asFiled.pdf ), the League asked the FCC to establish a regulatory regime that would segment bands by necessary bandwidths ranging from 200 Hz to 100 kHz rather than by emission mode. The ARRL now is urging the FCC to adopt a "subset” of the rules http://www.arrl.org/announce/regulatory/rm-11306/appendixA.html contained in its original petition that largely affects only the amateur bands at 28 MHz and above.

“Because the proposals affecting the bands above 28 MHz had not aroused much controversy, they were retained in the shortened list,” ARRL CEO David Sumner, K1ZZ, explained this week. “Regulation by bandwidth rather than by mode of emission remains controversial below 28 MHz because of its perceived potential impact on established operating patterns, so these proposals were removed from the list with one narrow exception.”

That exception addresses the fact that current rules impose no effective bandwidth limit on HF digital operation. “Digital emissions using multiple carriers, such as OFDM [orthogonal frequency division multiplexing], can be designed for any bandwidth while staying within the existing rules,” Sumner points out, “so, the subset of proposed rule changes includes a bandwidth limit of 3 kHz on RTTY and data emissions below 28 MHz.”

The proposed 3 kHz RTTY/data bandwidth limit aims to avoid the possibility existing under the present rules that a single digital station could monopolize large MF and HF band segments. In an Erratum this week the ARRL also asked the FCC to retain the existing 500 Hz bandwidth limit that applies to certain automatically controlled RTTY/data stations under §97.221.

The ARRL proposal would amend the definition of “bandwidth” in §97.3(a)(8) to read: “For a given class of emission, the width of the frequency band which is sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions.” The rule references the definition of “necessary bandwidth” appearing in Parts 2 and 97 of the FCC rules.

If the FCC adopts the League’s revised proposals, the 10, 6 and 2 meter amateur bands would be segmented into subbands allowing maximum emission bandwidths of 200 Hz, 500 Hz, 3.0 kHz (with an exception for double-sideband, full-carrier AM phone), 16 kHz or 100 kHz. Above 222 MHz, the entire emission must be within the allocated Amateur Radio band to comply with §97.307(d).

Sumner concedes that the subset of proposed rule changes in RM-11306 would provide less protection to CW, RTTY and other narrowband modes than the League’s original proposals afforded, but not less than the existing rules provide. “In fact, protection against interference from wideband digital modes would be increased, not decreased, even by adoption of the subset,” he contended.

Some confusion arose because of an inadvertent omission in the initial notice of a meeting on this subject between ARRL officials and FCC staff. This week's Erratum addressed that issue.

Additional consternation followed in the wake of a widely circulated, but erroneous, comment alleging "the complete absence of CW as a mode in the table of HF modes" the ARRL submitted. The ARRL has proposed no change to §97.305(a) of the rules, which authorizes CW on all amateur frequencies except on 60 meters.

The League has petitioned the FCC to permit CW and other modes on 60 meters, in addition to the presently permitted upper-sideband SSB.

After studying the topic several years, the ARRL Board of Directors continues to support the principles of regulation by bandwidth contained in the original RM-11306 petition.

“Regulation by bandwidth provides a better regulatory framework, not only for the introduction of future digital emissions but for the protection of traditional narrowband modes as well,” Sumner asserted this week. He expressed the hope that the subset of RM-11306 modifications offers an alternative that “will make it easier for the FCC to move at least part of the way in that direction.”