Wednesday 7 February 2018

FCC's Noise Floor 'Study'?




It seems like the FCC's recent interest in doing an in depth study of the growing RF spectrum noise floor has taken a new twist.



The FCC's apparent lack of real action in gathering the data needed to make serious inroads into RF noise pollution has drawn the attention of the ARRL, which voiced their concerns in a recent ARRL Letter as well as in their formal response to the FCC.

In response to the FCC's Public Notice (ET Docket No. 17-340) Spectrum Management proposals, the 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." It would seem that the proposed in-depth study never even happened and the term 'noise' has morphed into an 'interference' issue!

The FCC's paper proposed a number of guiding 'principles' in going forward with spectrum management policies, loosely based on the concept that more emphasis on eliminating 'interference' should be placed on receivers along with continued development of transmitter spectral purity and that with increased spectrum crowding, users will simply have to expect and accept certain, as yet unspecified, levels of interference!

It sounds suspiciously as if the FCC has decided that the source of any noise / interference problems have become too large to control and have passed the buck to equipment manufacturers in order to solve the growing problem for users!

“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.

In their series of guiding principles relating to 'interference realities', the FCC has issued a number of broad, somewhat ambiguous statements, that might be interpreted in any number of odd ways ...

"Principle #1 -- Harmful interference is affected by the characteristics of both a transmitting service and a nearby receiving service in frequency, space or time;

Principle #2 – All [radio] services should plan for non-harmful interference from signals that are nearby in frequency, space or time, both now and for any changes that occur in the future;

Principle #3 – Even under ideal conditions, the electromagnetic environment is unpredictable. Operators should expect and plan for occasional service degradation or interruption. The Commission should not base its rules on exceptional events;

Principle #4 – Receivers are responsible for mitigating interference outside their assigned channels;

Principle #5 – Systems are expected to use techniques at all layers of the stack to mitigate degradation from interference;

Principle #6 – Transmitters are responsible for minimizing the amount of their transmitted energy that appears outside their assigned frequencies and licensed areas;

Principle #7 – Services under FCC jurisdiction are expected to disclose the relevant standards, guidelines and operating characteristics of their systems to the Commission if they expect protection from harmful interference;"

The ARRL response argued that:

“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 ..."

Specifically they argue that amateurs are unique users and able to recognize harmful interference beyond their control and should not be subjected to the same restrictions (ie. get ready to accept new levels of yet undefined interference levels) as commercial users.

"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."

The ARRL seems somewhat forgetful when it comes to several long-standing complaints of inappropriate amateur-generated interference and bad behaviours which have been ignored for far too long ... problems well beyond 'cooperative resolution' by affected amateurs.

Although the ARRL does agree with many of the FCC's proposals, they doggedly insist that the FCC's apparent quashing of their original noise data investigations is critical to going forward:

“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.”

With Washington's drastic cutbacks in FCC field-office investigators and overall budget trimming, it seems that the FCC is still relentlessly driven to eradicate all forms of illegal (pirate) broadcasting. It's a pity that they don't display the same zeal for dealing with the illegal imports and distribution of the offshore equipment that is quickly killing our ability to hear anything on the ham bands ... without selling-off and moving to several acres in the country.

2 comments:

Photon said...

A very interesting post - thank you.

One always tries to be positive, even in these dark days. But the reality is pretty much as you conclude: there is no money, and expensive investigations and enforcement actions are now firmly to be avoided as far as possible.

The situation is much the same in the UK. The clear message is a perverse: 'yes, we import Chinese rubbish without much or any import checks, and we know they fiddle the CE/FCC checks. But we can't possibly police everything and, so, you hams who only bring us grief and no money, will have to put up with it. After all, you are hardly of any political influence or relevance, are you?'

Rather than accept we are being treated as mugs, I fear the self-importance of many of these 'representative bodies' means they (a) continue to do more of the same and, as a result are (b) demonstrably ineffective.

I can't afford tens of acres of land, but I have thankfully been given permission to use such isolated land, and make the very most of it!

Steve McDonald said...

Thank you for your excellent analysis! Unlike you, I do feel that indeed, 'the sky is (slowly) falling', when it comes to amateur radio as it has been for so long and many of the digital modes are the only thing keeping some folks from packing it in altogether.

Ham radio from the once-quiet city is, for so many, no longer possible and even the suburbs are a challenge. Of course, many do accept this as a challenge and some remarkable work can be done ... I see it every day on 630m, a noisy band where many city or suburbanites with small backyard antennas, are having great success in working across North America. Ham ingenuity at its finest. So maybe the glass is 'half-full' as you have suggested!

Truthfully, we can no longer look to federal agencies to police what crap is being sold and the noise-floor din continues to rise every year ... that's the 'half-empty' part I guess!