Re: PISC Informal Complaint and Petition for Rulemaking.

First of all, truly a very comprehensive and astute legal treatise. I found it very informative and quite sensible from the legal and policy standpoint, and even agree with most of the proposed rules. I firmly believe that spectrum winners should have exclusive rights to the spectrum they paid billions for and spend billions more to build and operate infrastructure. Further, I also believe there should be no Part 74 BAS operations is dedicated (unshared) PS spectrum as a matter of policy.

However, it's too bad the engineering concepts, and an understanding of the logisitics of Part 74 BAS device use in production environments don't come anywhere close to the same level of competency as the legal arguments.

So, let's look at some of the PISC “technical” points . . .

1) “. . . to prevent interference with public safety and commercial systems licensed to operate in the
bands currently allocated to channels 52-69 . . .”

I don't know how this was arrived at (do you have any tests, studies or complaints of a similar nature you could cite?) but to believe that a low power narrowband Part 74 BAS device, or even a cluster of devices as would be found in a large scale production could pose a significant interference potential to broadband data devices (future WSD's and PS data terminals) or high power narrowband communications (PS 700MHz two-way radio equipment), indicates no understanding (okay, maybe just enough to be dangerous) of RF propagation, free space path loss, body absorption, receive selectivity, digital transmission characteristics, digital receive decoding, FM transmission and reception principles, relative power level desense, high density Part 74 BAS device frequency coordination practices, channel bandwidth/guardband requirements, PS radio system architectures or PS radio practices.

Is it possible a PS person's radio could experience interference from a Part 74 device if in a fringe area? Sure; “anything” is possible. But if that EMS tech, police officer or fire fighter is truly in a fringe area with respect to his base station operations and with no mobile repeater link or other local ground operations to rely on, I would be *far more* worried about the cell phone or WSD on said PS officer's belt or the hundreds of WSD's roaming near him/her (and so should you) causing problems than a BAS device further away.

Further, if you're so concerned about Part 74 device interference to PS systems, why do you make no mention of banning Part 74 operations in T-band (470-512MHz) in the 13 MEAs and Gulf port region? I've not been able to find a single interference complaint from a T-band PS licensee that was due to a Part 74 BAS device, legal or illegal, since T-band was authorized over twenty years ago, but then I get flustered with the FCC search engine.
2) “PISC recommends authorizing the GWMS to use the 2020-2025MHz channel potentially available following resolution of the AWS-2 and AWS-3 proceeding pending before the Commission.”

This spectrum most definitely offers possibilities for non-audio quality critical applications (wireless intercom and IFB's) but it is not the answer you might believe it to be. RF propagation (body absorption and obstruction hindrance) at those frequencies is problematic enough that critical audio (the sound you as the paying audience member or TV viewer want to hear) would suffer too greatly. If the spectrum is that good, why not put WSDs in the millimeter wave spectrum?

(cont'd in next post . . .)

(. . . Cont'd)

3) “To grasp the immediacy and urgency of the situation, one need only imagine the problem of first responders summoned to an emergency at a performance of The Little Mermaid, only to discover that the radio systems they rely upon to penetrate walls and provide medical telemetry have encountered an ocean of interference from the intense unauthorized use of wireless microphones apparently common on Broadway.”

“If unauthorized wireless microphone use converts houses of worship, theaters, and other such venues of intense unauthorized use into concentrated pools of UHF interference, it will significantly impede future public safety operations in these venues. Medical first responders rushing to treat a cardiac victim at a Broadway Theater, or fire fighters and police combating a future natural catastrophe or 9/11-style terrorist attack, must be able to rely on their interoperable wireless equipment with absolute confidence.”

“As reported by unauthorized users in Docket 04-186, certain venues, such as theaters and large houses of worship (so called “megachurches”), use hundreds of wireless microphones intensively while in operation. This creates a veritable cloud of RF interference on the channels of the new commercial and public safety services on UHF Channels 52-69. A team of first responders summoned to treat a heart attack victim at a church running into such a wireless microphone cloud will find that their new radios capable of penetrating walls and providing medical telemetry are now useless. Firefighters and police could potentially find their new interoperative systems fatally unreliable in a building such as a theater or corporate conference center where such clouds of interference from wireless microphone systems left operating can spring up unexpectedly.”

*Sigh* I'll make you an offer: I won't argue points of law or regulation, you don't do RF engineering analysis. Okay, let me make you a different offer: You bring the PS radio devices of your choice (there's a significant selection of 700MHz equipment available on the market) and I'll provide the Broadway show (ask Michael Marcus how he liked Phantom last month. Better yet, ask him how he liked dinner - Rachel's is quite a nice restaurant. Though I must confess, I have yet to try what looks to be a great bottle of wine he presented.) The point is, these PISC statements are based on unsubstantiated hypothetical posturing worthy of some of Shure's or MSTV's more irresponsible doom and gloom boasts. (After reading your blog for several months now, I would have thought better of you.)
4) “For those concerned that bands outside the broadcast bands would not prove as useful, PISC notes that Ofcom in the United Kingdom recommended migrating wireless microphone users out of the broadcast bands to a single 8 MHz
channel.”

First, Ofcom has only recommended this, they haven't formalized any regulation. Secondly, this is being vigorously fought by BEIRG (http://www.beirg.org.uk) because 8MHz is simply an insufficient amount of spectrum to present a medium to large scale event, using current FM technology. Third, there would still exist the half dozen or so license free frequencies allocated for PMSE.
5) “Similarly, in Docket No. 04-186, Marcus Spectrum Solutions has described how a transition to digital wireless microphone systems at alternative frequencies would improve both audio performance and spectrum efficiency. While these proposals demonstrate that a number of experts believe that wireless microphones could both function entirely outside the broadcast bands, and that removal of these services from the broadcast bands would improve spectrum efficiency . . .”

Not quite. Whereas digital wireless mics are and will continue to be more spectrally efficient, that's only one third of the digital trinity we have yet to solve. Just like “good, fast, cheap; pick any two”, we currently have a digital brick wall: high audio quality, spectral efficiency and low latency (<2mS); pick any two. Too bad you didn't site my comment to Michael's filing on his blog (https://www.blogger.com/com...). Oh, and ask any professional sound designer or mixer who's used them; the digital Sony's don't sound that good.

(cont'd in next post . . .)

(. . . cont'd)

6) “Furthermore, years of unauthorized use have demonstrated clearly that even unsupervised, widespread, and often intense use of wireless devices in the vacant broadcast bands does not interfere with television broadcast service.”

Because broadcast TV signals are static, known, measurable and the professional production community puts great effort in frequency coordination and band planning before BAS devices are deployed. Something you won't be able to do with auto scanning “everything else be damned” WSDs.
7) “. . . GWMS would have co-equal rights with any authorized white spaces devices and would not be eligible for “beacons” under consideration for licensed users. Rather, GWMS users and white space devices users would resolve interference issues through mutual negotiation.”

And how do you propose the BAS equipment provider/user mutually negotiate with the hundreds, thousands or tens of thousands of audience members with WSDs entering the performance venue an hour before show time?
8) “PISC observe that this represents a considerable improvement for unauthorized wireless microphone users, as they at present do not enjoy any rights as against interference from devices authorized by the Commission . . .”

Improvement? Going from a static, known, measurable transmission that for the most part can be easily avoided to a free for all dynamic undocumented mosh pit is hardly an improvement from an engineering standpoint. (Though I have no doubt the legal industry thrives on such confusion and disorganization in the marketplace.)

9) “Making GWMS users and WSD users coequal therefore provides adequate protection for GWMS users . . .”

Only legally, not operationally or in practice.
10) “And, in any event, sensing and other interference mitigation technologies will provide adequate protection for GWMS”

Only if WSD manufacturers don't cheat; provide the FCC with compliant samples to verify/certify, but flood the marketplace with product that doesn't meet that sensing specification. (Remember the FM radio transmitters for the Walkmans and iPods?)
Let me conclude with some points I've made previously on your blog and on Sascha Meinrath's and Michael's. Yes, I agree current FM technology based Part 74 BAS devices are spectrally inefficient, in widespread illegal use and this must change. We as industry professional and you as paying audience members or TV viewers will have to deal with lesser audio, be it quality or quantity, for the near future until some significant RF development is made to deliver the level of audio quality (frequency response and latency) we currently enjoy in a more spectrally efficient manner.

Spectrum lessees (auction winners) and public safety should have exclusive use of their spectrum as a matter of policy, not interference mitigation. If careful and proper frequency coordination by the BAS device user is not practiced, they will suffer tremendously greater interference than they will ever create. Thus self coordination is in the BAS device user's primary interest.

I continue to extend an invitation to you to come to a larger production where BAS devices are deployed; I'll happily show you what we do and how we do it long before the audience enters the room.

Henry:

I hope you will raise all these points if the FCC puts the Petition out on notice or takes other action, as the FCC indicated.

I will point out that while interference cases even in this environment are rare, they do occur. We cited one — in re Flecco. I also had a passing citation to a 2001 rulemaking with additional interference complaints.

The engineers I talked to said there is a real danger here of interference. I also suggest that while a 5 MHz channel in 2020-2025 MHz would not precisely replicate existing microphones as currently designed, they will prove sufficient for most purposes and thus relieve crowding in the remaining UHF bands — as well as provide an alternative to those who think sensing is black magic.

Come on Harold.

Fleco was about a non-type approved wireless mic system operating in an unauthorized frequency band. This has nothing to do with Part 74 service, equipment or standard practices.

If you're referring to the March 20th 2001 NPRM, I can find no references to any actual complaints regarding interference experienced by a licensee due to Part 74 BAS operations (please point them out if I missed them). I see only references to comments filed concerning possible interference that might happen. So, has there been any interference since the revision to the rules?

Engineering is more than just theory; it's in large part practice and practical application. Do any of the engineers you spoke with have practical experience with Part 74 BAS devices and operation in an entertainment production environment? Using your argument, the FCC should have immediately ordered the shut down of all 800MHz Nextel operations as soon as it was determined they were interfering with PS operations, on a nationwide basis no less.

But on a positive note, I'll happily take the 5MHz at 2GHz. I can put a not insignificant number of less critical, short range (relatively speaking) audio paths up there freeing up UHF for the money channels.

BTW, I'm quite amused by the Google ads that appear on the web page for this post: All for retailers selling wireless mics.