01/31/2018

In comments[1] to the FCC on a series of Technological Advisory Council (TAC) spectrum management policy recommendations, ARRL said that while some of the Council's recommendations are valid, it would be "highly inappropriate" to generalize about applying them broadly in all radio services. The comments, filed on January 31, were in response to a December 1, 2017, Public Notice in ET Docket No. 17-340. ARRL took the opportunity to strongly urge the FCC to reinstate a 2016 TAC noise floor study, which, ARRL asserted, apparently was terminated before it even got started.

"Indeed, it is difficult to imagine how the Commission can now?suggest the adoption of specific spectrum management principles, incorporating such concepts as receiver immunity, HCTs [harm claim thresholds], and interference temperature determinations without having?a firm grasp on ambient noise levels in basic RF environments and geographical areas," the League told the FCC.

ARRL reiterated its encouragement for the FCC to incorporate receiver performance specifications into US spectrum policy on a broader basis. "ARRL accepts?that increased spectrum user density is the inevitable result of new wireless services," the League said. "Given that this intensification of the use of the radio spectrum will necessitate new overlays of dissimilar radio services?in increasingly shared spectrum, it is necessary to depart from the traditional regulatory model that the Commission has utilized for spectrum allocations."

That model, ARRL said, has, almost without exception, placed limits only on transmitters, while the inability of some receivers to reject out-of-band signals "constrains new allocations in adjacent bands." This calls for what ARRL called "a 'holistic' approach to transmitter and receiver performance."

"Requiring better performance from receivers or RF-susceptible devices is a valid, reasonable, and long overdue requirement," ARRL said, "but the major goal of doing so should be to prevent instances of interference, not solely to allow the overlay of otherwise incompatible sharing partners in deployed spectrum to the detriment of incumbents."

ARRL argued, however, that the Amateur Service should not be subject to receiver immunity standards, because licensees employ a wide range of propagation, emissions, bandwidths, power levels, receivers, and antennas, making any receiver performance standards arbitrary and compromising the Service's experimental nature. They also are able to differentiate between interference from nearby spurious or out-of-band signals and that caused by receiver deficiencies. The HCT concept does not fit the Amateur Service particularly well, either, the League said; any interference hams suffer from each other is resolved cooperatively. Brute-force overload also occurs occasionally but is resolved by licensees without FCC intervention.

"Receiver immunity is not an intra-service issue in the Amateur Service," ARRL said. "The issue?is, rather, protection from spurious and out-of-band emissions from other services."

ARRL said that while the TAC's allocation principles include over-generalizations, the Council is "very much on the right track" with such concepts as receiver immunity standards for certain radio services and, especially, for consumer electronics "and the initiation of necessary and urgent programs, such as interference-hunting teams, to supplement the Commission's meager enforcement resources." ARRL said it looks forward to working with the FCC in developing an interference-tracking corps.

ARRL also supported the creation of a public database of past radio-related enforcement activities. "Given the very limited, and, recently, severely diminished, availability of [FCC] field enforcement resources, it is urgent to publicize those enforcement actions that pertain to intentional or harmful interference in order to maximize the deterrence value of each one," ARRL said. The longer a licensee gets away with violating the rules without visible FCC sanction, ARRL explained, the more the violator is encouraged to continue the behavior, which others may then imitate. What little FCC enforcement is necessary must be timely and visible, ARRL said.

ARRL returned, however, to its assertion that adopting any next-generation spectrum management techniques such as those the TAC recommends, "presupposes the existence of a knowledge database regarding ambient noise levels in certain environments. Sadly, that information does not exist, and it won't anytime soon," ARRL said, because the FCC took the TAC off the noise study project.

"That, in ARRL's view, is a big mistake," the League contended. "No system of spectrum management incorporating [harm claim thresholds] and receiver immunity levels can be accurately implemented" without the noise study data.

"That study is more important now than ever before," ARRL concluded, "and it is increasingly urgent as a prerequisite for any new spectrum management policies."


[1] https://ecfsapi.fcc.gov/file/10131291865923/201720COMMENTS20TAC20Policy20FINAL.pdf

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