Why Arts and Cultural Venues Should Support White Space Devices (and be Critical Consumers of Shure's FUD).

"these WSD detractors have systematically ignored data showing that even the pre-prototype WSDs being tested by the FCC’s Office of Engineering and Technology work exceptionally well."

Could you eleborate on "work exceptionally well"? The testing to date has consisted only of sensing and detection of DTV and wireless microphone signals, not upload, download, RF propagation or transmit performance of any kind. Further, this testing produced questionable results: There were too many false positives (including channel 37!) and some false negatives that from an engineering perspective, there really is no justification to conclude they "work well." From a propaganda perspective however, one can interpret anything.

"What is particularly ironic is that unlicensed wireless microphones are already in use throughout the United States—these devices already use unused TV bands, and have done so for years; yet the same companies that manufacture and use wireless microphones are the ones saying that other devices won’t work."

Wrong. The entertainment production community is not saying the devices won't work (if designed and built properly, there's no reason they shouldn't), rather we're saying they'll cause detrimental interference to Part 74 devices.

"For Shure Incorporated, it means that a whole new generation of wireless microphones—white space device wireless microphones—will be entering the market, dramatically increasing competition and lowering the costs of this hardware."

and

"As WSD technologies are integrated into next-generation wireless microphones and other media equipment,"

How will an audio bandwidth limited, high latency device (the WSD) compete with current wireless microphone performance? Do you not understand that the goal of a wireless mic is to deliver audio quality the equivalent of a wired mic? That latencies of more than approximately 3mS and an audio bandwith less than 80Hz-15kHz is unacceptable for 99% of performance requirements?

"these systems will be substantially less prone to interference than today’s “dumb” equipment (which are often incapable of sensing whether other devices are transmitting on the channel they intend to use)"

It's apparent you're not familiar with standard wireless microphone practices. The first thing any wireless mic user does is turn on the *receiver only* and looks for clear frequencies, either manually or via the receiver's built in scanning feature. More professional users utilize external scanners or spectrum analyzers. Only *after* clear channels are determined is the transmitter tuned to that frequency and usage commences.

"Today more than 3,000 wireless ISPs and rural telephone cooperatives already rely on the current “junk” bands of unlicensed spectrum to provide broadband to remote customers, mostly in rural areas. Which is why the Wireless Internet Service Provider Association (WISPA) and the National Telecom Cooperative Association (NCTA) have been advocates of opening the TV white spaces for unlicensed access."

So. what's to prevent the UHF white spaces from becoming another "junk" band?

"The FCC is completing a critical phase of the process needed to bring WSDs to consumers. Extensive feasibility testing has been conducted and extensively documented, and this testing has demonstrated that WSDs can and do work. A new round of feasibility testing is currently underway and will add further support for the viability of WSD technologies."

Again, the only testing the FCC has done to date is sensing and detection of DTV and Part 74 device signals. There have been no tests of EIRP, out of band transmissions, timing sequene or any other criteria the FCC looks at when testing intentional radiators.

"For arts and cultural organizations, this process (and white space devices generally), have the potential to add much needed tools to help us conduct our work. New, less-expensive video and audio communications equipment . . ."

You'll really have to explain this one to me; broadband digital transmission schemes immediately preclude both high audio quality *and* low latency.

Sascha, I don't care what your policy position is, but please don't use faulty engineering or technical performance to support it. You're doing exactly what you accuse Shure, NAB, MSTV et al of doing and despise.

Great article. I'm going to point to this as a reference whenever I say "white spaces," and someone stares blankly.

Hi Henry,

Here's some quick links to various information to address your points...

You wrote:

"Could you eleborate on 'work exceptionally well'? The testing to date has consisted only of sensing and detection of DTV and wireless microphone signals, not upload, download, RF propagation or transmit performance of any kind. Further, this testing produced questionable results: There were too many false positives."

As I document in the Policy Backgrounder New America Foundation released last year, "Unlicensed 'White Space Device' Operations on the TV Band and the Myth of Harmful Interference," the Philips prototype performed perfectly (with a 100% accuracy rate) within its technical specifications (and even a bit outside of them). You can take a look at Figure 3-4 from the original FCC report to verify.

During the recent tests on Broadway, the Philips device once again correctly identified occupied channels. From what I've been told by people who were at the actual tests, the "false positives" you claim were due to wireless microphones operating within occupied TV channels -- i.e., even when the microphone was off, the WSDs were picking up TV station signals and thus (correctly) identifying these channels as occupied. The August 19, 2008 FCC filing by the White Spaces Coalition formally documents this fact.

Shared Spectrum's founder recently weighed into the white spaces debate -- the Washington post stated that "The broadcasters' position is 'not what the DoD thinks,' McHenry said. 'It works in the harshest environments.'" Unless one argues that physics works differently for the military, what works for them should work fine for the rest of us.

I would agree with you that these devices are still prototypes and will be improved over time, but there's more than enough evidence that they work exceptionally well to move forward with the FCC developing technical specifications.

You wrote:

"The entertainment production community is not saying the devices won't work (if designed and built properly, there's no reason they shouldn't), rather we're saying they'll cause detrimental interference to Part 74 devices."

The evidence collected thus far is that WSDs are able to sense and avoid Part 74 devices, which directly addresses this concern. However, New America Foundation and many other groups have also proposed the use of wireless beaconing technology specifically to further ameliorate this concern. Adaptrum just put in a filing yesterday that's worth a read -- they actually built and tested a prototype beaconing system as a proof-of-concept and included their data and methodology in their FCC filing. As we've been stating for quite some time, there are numerous ways to protect wireless microphones, any one of which is more than adequate to ensure non-interference. Comprehensive testing by the DoD likewise backs up the claim that WSDs can operate between occupied channels without causing harmful interference.

You wrote:

"How will an audio bandwidth limited, high latency device (the WSD) compete with current wireless microphone performance? Do you not understand that the goal of a wireless mic is to deliver audio quality the equivalent of a wired mic? That latencies of more than approximately 3mS and an audio bandwith less than 80Hz-15kHz is unacceptable for 99% of performance requirements?"

The premise of your question is that WSDs and wireless microphones would operate on the same frequencies -- which is simply wrong. As you know, WSDs avoid wireless microphones and other legally licensed uses of available spectrum and utilize vacant frequencies -- so I'm not sure what your point is.

In response to my statement, "these systems will be substantially less prone to interference than today’s 'dumb' equipment (which are often incapable of sensing whether other devices are transmitting on the channel they intend to use)," you wrote:

"It's apparent you're not familiar with standard wireless microphone practices. The first thing any wireless mic user does is turn on the *receiver only* and looks for clear frequencies, either manually or via the receiver's built in scanning feature. More professional users utilize external scanners or spectrum analyzers. Only *after* clear channels are determined is the transmitter tuned to that frequency and usage commences."

Actually, you are making making my point exactly -- today's equipment (as you state yourself) is "dumb" and requires human intervention to identify unoccupied frequencies. On the other hand, WSDs automatically conduct the assessments that "more professional users" do and integrate them into their normal usage patterns -- they don't require human intervention to conduct their spectrum analyses. In essence, a WSD's microprocessors replace the need for human fine-tuning (in much the same way that most of today's AM/FM radios don't need humans to turn knobs to tune into specific stations).

You wrote:

So. what's to prevent the UHF white spaces from becoming another "junk" band?

First of all, "junk" is quoted because the 2.4GHz band has been anything but junk -- it's been an incredibly valuable, useful, and much-used area of the electromagnetic spectrum. More to your point, low-powered access, the size of the new spectrum made available, improvements in spectrum access efficiencies, and continuing efforts to open up additional bands of the public airwaves to public access all make it exceedingly unlikely that any one band would become congested enough to attain "junk" status. The only reason why 2.4 GHz has become so crowded is because so many people have fought for so long against opening up new spectrum -- in essence, the artificial scarcity caused by the length of time it's taken to open up new frequencies has caused the problem and now people are arguing that the very problem they've helped cause is a rationale for not moving forward. This FCC proceeding (04-186) began almost half-a-decade ago (and if you count the 2002 proceedings before that, you can tack on a few more years to the timetable).

Studies of actual spectrum use show that at any given point in time, less than 10% of the available spectrum is in use. Because the FCC's spectrum regulations have failed to keep up with changing technologies, it's created enormous artificial scarcities. This is the basis for the new analysis that my colleague, Victor Pickard, are working on -- we'll be talking about our paper, "Revitalizing the Public Airwaves: Opportunistic Unlicensed Reuse of Government Spectrum," at the upcoming Telecommunications Policy and Research Conference.

You wrote:

the only testing the FCC has done to date is sensing and detection of DTV and Part 74 device signals. There have been no tests of EIRP, out of band transmissions, timing sequene or any other criteria the FCC looks at when testing intentional radiators.

There are an infinite number of different tests, procedures, and analyses that could be conducted. The folks that don't want to see WSDs have managed to draw out this process for years through their continuing claims that yet more testing needs to be conducted. But the purpose of this phase of the FCC's due diligence is simply to determine whether WSD technology is viable. Clearly it is (especially if the military is already deploying it for battlefield use). The problem is that folks that want to believe that there could be a problem can always come up with some other way in which WSDs might (under certain circumstances and conditions and assuming particular criteria) cause problems. The fact is, even these first-generation prototypes have fared quite well -- the next step is for the FCC to create technical specifications for how WSDs should operate -- obviously, they're not going to create specs that cause massive out-of-band emissions or other interference problems. What anti-WSD folks don't want people to know is that all of this additional due diligence was never done for 2.4 GHz (Part 15) devices -- the FCC created the tech specs and just let them loose into the world. Amazingly, TV didn't end, cell phone systems didn't explode, and all other manner of "the sky is falling" paranoia didn't come to pass. And when WSDs are a reality, a number of folks who have so vociferously argued against them are going to look pretty foolish in hindsight.

You wrote:

You'll really have to explain this one to me; broadband digital transmission schemes immediately preclude both high audio quality *and* low latency.

I'm not sure what you're arguing here -- the notion that broadband digital transmissions preclude high audio quality and low latency is verifiably wrong. I'm certain you must have meant to say something else.

You wrote:

Sascha, I don't care what your policy position is, but please don't use faulty engineering or technical performance to support it. You're doing exactly what you accuse Shure, NAB, MSTV et al of doing and despise.

What are you referring to when you say I'm using "faulty engineering or technical performance"? I'm basing my assessments on primary sourcing from the FCC's own reports on WSDs. Shared Spectrum has also put out a lot of information on it's WSD development efforts for the DARPA XG program -- you can read the results from their field tests (back in 2006!) here and download the synopsis and methodology here (this is a 13MB file). So before you go accusing people of making things up, you should check their sources. Thus far, Shure, NAB, and MSTV have been engaging in a massive misinformation campaign to convince people that WSDs won't work. My question to you is, what happens when they're shown to be wrong -- after all, NAB was against satellite TV, cellular phone information services, cable TV, the VCR, TiVo, and low-power FM radio -- to name just a few of the technological innovations they fought so vociferously against.

*** Sascha - My responses to your points. ***

Hi Henry,

Here's some quick links to various information to address your points...

You wrote:

"Could you elaborate on 'work exceptionally well'? The testing to date has consisted only of sensing and detection of DTV and wireless microphone signals, not upload, download, RF propagation or transmit performance of any kind. Further, this testing produced questionable results: There were too many false positives."

As I document in the Policy Backgrounder New America Foundation released last year, "Unlicensed 'White Space Device' Operations on the TV Band and the Myth of Harmful Interference," the Philips prototype performed perfectly (with a 100% accuracy rate) within its technical specifications (and even a bit outside of them). You can take a look at Figure 3-4 from the original FCC report to verify.

*** This was a DTV sensing test only with the DUT connected directly to the DTV signal generator, which immediately precludes the DUT from having to demonstrate selectivity, IM and IP3 performance. No wireless mic signals were tested. So not a very conclusive or comprehensive test on which to base an absolute positive or negative. Just because you can swim well in a calm swimming pool, doesn’t mean you’re effective in the turbulent waters of an ocean. ***

During the recent tests on Broadway, the Philips device once again correctly identified occupied channels. From what I've been told by people who were at the actual tests, the "false positives" you claim were due to wireless microphones operating within occupied TV channels -- i.e., even when the microphone was off, the WSDs were picking up TV station signals and thus (correctly) identifying these channels as occupied. The August 19, 2008 FCC filing by the White Spaces Coalition formally documents this fact.

*** Not quite. At the Broadway test (at which I was present and Ed Thomas was not), there were two TV channels the Philips unit showed as being available during the first sweep which was with all mics turned off. In the second sweep with the mics were turned on, the Philips device showed both those channels as being occupied - except that there were no mics transmitting in either of those two channels. And one of the “occupied” channels was 37. Again, not what an engineer would consider to “work exceptionally well”. ***.

Shared Spectrum's founder recently weighed into the white spaces debate -- the Washington post stated that "The broadcasters' position is 'not what the DoD thinks,' McHenry said. 'It works in the harshest environments.'" Unless one argues that physics works differently for the military, what works for them should work fine for the rest of us.

*** If the white space device manufacturers are going to employ the same level of design, component and build quality of military systems, with little regard to size and cost, I have little doubt they would work quite well. None would be sold due to size and cost, but they would work. Further, the Shared Spectrum proof of concept device is a large scale test bed without the effects of small scale component and package interaction between the IF, LO and PA sections. ***

I would agree with you that these devices are still prototypes and will be improved over time, but there's more than enough evidence that they work exceptionally well to move forward with the FCC developing technical specifications.

*** There is *not* more than enough evidence that they work exceptionally well. There is proof of concept and more than enough evidence to continue to expend R&D resources to improve the hardware and software design to produce a viable product. ***

You wrote:

"The entertainment production community is not saying the devices won't work (if designed and built properly, there's no reason they shouldn't), rather we're saying they'll cause detrimental interference to Part 74 devices."

The evidence collected thus far is that WSDs are able to sense and avoid Part 74 devices, which directly addresses this concern.

*** Not in the tests I witnessed. ***

However, New America Foundation and many other groups have also proposed the use of wireless beaconing technology specifically to further ameliorate this concern. Adaptrum just put in a filing yesterday that's worth a read -- they actually built and tested a prototype beaconing system as a proof-of-concept and included their data and methodology in their FCC filing. As we've been stating for quite some time, there are numerous ways to protect wireless microphones, any one of which is more than adequate to ensure non-interference.

*** I agree. Let’s see proof of concept of the beacon proposal that doesn’t itself eat into spectrum. ***

Comprehensive testing by the DoD likewise backs up the claim that WSDs can operate between occupied channels without causing harmful interference.

*** Again, If the white space device manufacturers are going to employ the same level of design, component and build quality of military systems (with little concern of cost), I have little doubt they would work well. ***

You wrote:

"How will an audio bandwidth limited, high latency device (the WSD) compete with current wireless microphone performance? Do you not understand that the goal of a wireless mic is to deliver audio quality the equivalent of a wired mic? That latencies of more than approximately 3mS and an audio bandwith less than 80Hz-15kHz is unacceptable for 99% of performance requirements?"

The premise of your question is that WSDs and wireless microphones would operate on the same frequencies

*** No it’s not. The premise of my question is that a WSDs will never deliver the high audio quality and ultra-low latency of analog [relatively] narrowband FM. ***

In response to my statement, "these systems will be substantially less prone to interference than today’s 'dumb' equipment (which are often incapable of sensing whether other devices are transmitting on the channel they intend to use)," you wrote:

"It's apparent you're not familiar with standard wireless microphone practices. The first thing any wireless mic user does is turn on the *receiver only* and looks for clear frequencies, either manually or via the receiver's built in scanning feature. More professional users utilize external scanners or spectrum analyzers. Only *after* clear channels are determined is the transmitter tuned to that frequency and usage commences."

Actually, you are making making my point exactly -- today's equipment (as you state yourself) is "dumb" and requires human intervention to identify unoccupied frequencies. On the other hand, WSDs automatically conduct the assessments that "more professional users" do and integrate them into their normal usage patterns -- they don't require human intervention to conduct their spectrum analyses. In essence, a WSD's microprocessors replace the need for human fine-tuning (in much the same way that most of today's AM/FM radios don't need humans to turn knobs to tune into specific stations).

*** Given the size and price point manufacturers of WSDs are striving for, and the tests I’ve witnessed using large platforms with no cost barrier, I have serious reservations that an auto-sensing/tuning WSD will be as effective as a professional user of Part 74 devices with a $8k-20k spectrum analyzer. I would however expect that to eventually change, but not by next February, or even Christmas 2009. ***

You wrote:

So. what's to prevent the UHF white spaces from becoming another "junk" band?

First of all, "junk" is quoted because the 2.4GHz band has been anything but junk -- it's been an incredibly valuable, useful, and much-used area of the electromagnetic spectrum. More to your point, low-powered access, the size of the new spectrum made available, improvements in spectrum access efficiencies, and continuing efforts to open up additional bands of the public airwaves to public access all make it exceedingly unlikely that any one band would become congested enough to attain "junk" status. The only reason why 2.4 GHz has become so crowded is because so many people have fought for so long against opening up new spectrum -- in essence, the artificial scarcity caused by the length of time it's taken to open up new frequencies has caused the problem and now people are arguing that the very problem they've helped cause is a rationale for not moving forward. This FCC proceeding (04-186) began almost half-a-decade ago (and if you count the 2002 proceedings before that, you can tack on a few more years to the timetable).

Studies of actual spectrum use show that at any given point in time, less than 10% of the available spectrum is in use. Because the FCC's spectrum regulations have failed to keep up with changing technologies, it's created enormous artificial scarcities. This is the basis for the new analysis that my colleague, Victor Pickard, are working on -- we'll be talking about our paper, "Revitalizing the Public Airwaves: Opportunistic Unlicensed Reuse of Government Spectrum," at the upcoming Telecommunications Policy and Research Conference.

*** I understand what you’re saying, and even agree to a point. But as long as there’s going to be license-free spectrum for mass market products, that spectrum will become saturated in high population areas, no matter how efficient time, frequency or coding schemes become. ***

You wrote:

the only testing the FCC has done to date is sensing and detection of DTV and Part 74 device signals. There have been no tests of EIRP, out of band transmissions, timing sequence or any other criteria the FCC looks at when testing intentional radiators.

There are an infinite number of different tests, procedures, and analyses that could be conducted. The folks that don't want to see WSDs have managed to draw out this process for years through their continuing claims that yet more testing needs to be conducted. But the purpose of this phase of the FCC's due diligence is simply to determine whether WSD technology is viable.

*** Agreed. But my response was to your more far reaching statement of “Extensive feasibility testing has been conducted and extensively documented, and this testing has demonstrated that WSDs can and do work. A new round of feasibility testing is currently underway and will add further support for the viability of WSD technologies" which sounds to me as if you believe the testing to date includes all tests an RF *transmission* device is *required* to undertake, and it is not.***

Clearly it is (especially if the military is already deploying it for battlefield use). The problem is that folks that want to believe that there could be a problem can always come up with some other way in which WSDs might (under certain circumstances and conditions and assuming particular criteria) cause problems. The fact is, even these first-generation prototypes have fared quite well

*** They didn’t fair well from an engineering perspective in the test at which I attended and witnessed. They clearly show proof of concept and promise with further development. And again, you can’t equate military grade hardware to mass market consumer goods. ***

-- the next step is for the FCC to create technical specifications for how WSDs should operate -- obviously, they're not going to create specs that cause massive out-of-band emissions or other interference problems.

*** No, the specs won’t call for out of band emissions, but that doesn’t mean the actual products destined for consumers, not the certification lab, won’t be out of spec. The small FM transmitters for iPods and the first DTV transmitters are good examples of that.

What anti-WSD folks don't want people to know is that all of this additional due diligence was never done for 2.4 GHz (Part 15) devices -- the FCC created the tech specs and just let them loose into the world. Amazingly, TV didn't end, cell phone systems didn't explode, and all other manner of "the sky is falling" paranoia didn't come to pass.

*** Because TV and cell phones are in completely different bands, and there were no [legal or illegal] incumbent devices in 2.4GHz when Michael Marcus proposed opening it up. Your statement is akin to saying the proliferation of pleasure boating by the general population never detrimentally affected automobile highway congestion, so what’s the problem? Apples and oranges.***

And when WSDs are a reality, a number of folks who have so vociferously argued against them are going to look pretty foolish in hindsight.

*** No doubt succeeding generations of WSD will work well, but I think the first generation units, based on what I’ve seen, are going to be problematic. ***

You wrote:

You'll really have to explain this one to me; broadband digital transmission schemes immediately preclude both high audio quality *and* low latency.

I'm not sure what you're arguing here -- the notion that broadband digital transmissions preclude high audio quality and low latency is verifiably wrong. I'm certain you must have meant to say something else.

*** Sorry - I was insufficient in my response: I meant to say given the multitude of primary functions and price point of proposed WSDs, they will never deliver the equivalent audio quality of a dedicated higher end analog FM wireless mic. ***

You wrote:

Sascha, I don't care what your policy position is, but please don't use faulty engineering or technical performance to support it. You're doing exactly what you accuse Shure, NAB, MSTV et al of doing and despise.

What are you referring to when you say I'm using "faulty engineering or technical performance"?

*** You’re not taking into consideration the details of the testing setup or procedures, the individual sweep results, the sonic performance of current high end wireless mics, how wireless mics are deployed, digital versus analog transmission characteristics (both good and bad on either side), relative size and costs of military grade systems and devices versus consumer, relative received energy levels at incumbent device antennas, stationary versus roaming uncoordinated transmitters, effects and component stage interactions of miniaturized designs versus large scale test beds . . . All things with which engineers must consider and account. ***

I'm basing my assessments on primary sourcing from the FCC's own reports on WSDs.

*** Considering the FCC has not released their report on the second round of testing which is the only round to do field tests, nor has any *transmission* tests been performed, I don’t understand from an engineering stand point why one (Shure and NAB included BTW) would rely so heavily on that first report. ***

Shared Spectrum has also put out a lot of information on it's WSD development efforts for the DARPA XG program -- you can read the results from their field tests (back in 2006!) here and download the synopsis and methodology here (this is a 13MB file). So before you go accusing people of making things up, you should check their sources.

*** I did: Again, the difference between military grade and consumer grade equipment, no engineering consideration given to the effects of device miniaturization and no consideration to target price points. ***

Thus far, Shure, NAB, and MSTV have been engaging in a massive misinformation campaign to convince people that WSDs won't work

*** True. But WSD proponents have been waging their own campaign that includes technical misinformation - The very reason and point of my comments to your and Harold Feld’s postings. Interesting however, that my similar comments to Michael Marcus’ (a degreed and experienced engineer) postings have yielded his interest in the details and practices of Part 74 device deployment and the ‘modifying’ of his position to not saying the WSD prototypes are unqualified successes. ***

My question to you is, what happens when they're shown to be wrong -- after all, NAB was against satellite TV, cellular phone information services, cable TV, the VCR, TiVo, and low-power FM radio -- to name just a few of the technological innovations they fought so vociferously against.

*** IF that happens, they will be embarrassed, will put a negative spin on it, and/or go silently into the dark. But I believe, based on what I’ve seen to date, the first generation of WSD will in fact be problematic because the people designing these things seem to be software coders, not RF engineers, and believe anything can be addressed by proper instruction sets and remedied with firmware updates and bug fixes with hardware a secondary consideration. ***

Henry, this is a really interesting discussion -- thanks for your responses. I remain optimistic about the viability of WSDs because of the rapidity of development and continuing testing successes. The article above was written after the first round of testing, but well before this second round on Broadway and at Fed Ex field was completed. As for the Philips device concern you raise, I'm not worried about devices claiming extra channels were occupied since that's simply affording more protection; however, do you know which channels these were? Given that several of the frequencies being tested were actually occupied TV stations (which is illegal for Broadway folks to do, but they were apparently doing that anyway), if folks were testing inside a big theater building, it's possible that these were just on the edge of the sensing threshold and thus it would be normal for the phenomenon you describe to occur. In terms of the transmitting issues you raise, New America Foundation hired University of Kansas researchers to test out a prototype WSD (see this article).

Perhaps the basis over our disagreement stems from the notion that WSDs would be secondary users of the spectrum, as are wireless microphones; as such neither has precedent, nor any protections over the other. What I hear many people arguing for is that Part 74 devices should be afforded protections above and beyond existing law and that barring that, no other users should be allowed on these frequencies. Part 74 devices are, in fact, auxiliary users of this space, they too must share this space. As the FCC states explicitly, "Low power auxiliary licensees will not be granted exclusive frequency assignments." Given that exceedingly few theaters even qualify to be legal users of wireless microphones (under Part 74.832) it's all the more important for those who are illegal users to start working more with public interest and consumer groups.

I am of the opinion that every effort should be made to protect existing users, but given that WSD prototypes have been remarkably successful thus far, I see no reason not to move forward with creating technical specifications. Opponents of WSDs will continue to claim uncertainty and spread fear about potential problems that may arise, but that's true whenever innovations are forthcoming.

In the end, I'm optimistic about WSDs -- having seen huge leaps and strides just in the past 6 months -- and feel that their technologies (along with the beaconing systems that are being proposed) offer more than ample protection for existing users (even if they're illegal -- and folks really should read Parts 74.6 and 74.832 so folks understand that theaters are by and large illegal and unlicensed users of wireless microphones. I'm very interested in finding ways to legalize these sorts of illegal users -- which is why I think it makes all the sense in the world to merge arts and cultural constituencies with public interest and consumer advocate constituencies. As long as Broadway folks take the position that they have rights that they don't actually have, and position public interest groups and consumer advocates as their enemy, they're both creating enemies that don't exist and placing themselves into a position that will afford far less protection and negotiating power to protect their own interests.

Either way, this is certainly a discussion that would be fun to have over a few pints. I'm not sure if you're DC-based or visit often, but it would be great to get together, grab some cocktail napkins and see if we can't draft up a mutually agreeable position on this. I think we'd find that we're in agreement more often than one would expect.

“I'm not worried about devices claiming extra channels were occupied since that's simply affording more protection; however, do you know which channels these were?”

I’ll get that to you when I return to my office on Monday.

“Given that several of the frequencies being tested were actually occupied TV stations (which is illegal for Broadway folks to do, but they were apparently doing that anyway)”

As opposed to ineligible user(s) operating without license?

“if folks were testing inside a big theater building, it's possible that these were just on the edge of the sensing threshold and thus it would be normal for the phenomenon you describe to occur.”

It’s normal for devices with low selectivity, not well designed front ends.

“In terms of the transmitting issues you raise, New America Foundation hired University of Kansas researchers to test out a prototype WSD (see this article).”

But Evans tested only interference potential to broadband DTV signals, not narrowband analog FM, and the two are completely different in terms of their interference susceptibility.

“Perhaps the basis over our disagreement stems from the notion that WSDs would be secondary users of the spectrum, as are wireless microphones; as such neither has precedent, nor any protections over the other. What I hear many people arguing for is that Part 74 devices should be afforded protections above and beyond existing law and that barring that, no other users should be allowed on these frequencies. Part 74 devices are, in fact, auxiliary users of this space, they too must share this space. As the FCC states explicitly, "Low power auxiliary licensees will not be granted exclusive frequency assignments." Given that exceedingly few theaters even qualify to be legal users of wireless microphones (under Part 74.832) it's all the more important for those who are illegal users to start working more with public interest and consumer groups.”

While I certainly agree that legally both Part 74 and white space devices must not cause interference and must accept any, my only point is that WSD proponents are making claims that WSD *won’t* cause interference when there’s been no transmission tests to date, so such a claim is premature.

“I am of the opinion that every effort should be made to protect existing users, but given that WSD prototypes have been remarkably successful thus far,”

Not by any valid or statistical engineering measurement I’ve seen demonstrated, though there is promise with further R&D.

“I see no reason not to move forward with creating technical specifications. Opponents of WSDs will continue to claim uncertainty and spread fear about potential problems that may arise, but that's true whenever innovations are forthcoming.”

I agree: Let’s establish technical performance specifications.

“In the end, I'm optimistic about WSDs -- having seen huge leaps and strides just in the past 6 months -- and feel that their technologies (along with the beaconing systems that are being proposed) offer more than ample protection for existing users”

But there’s only been a stand alone proof of concept by Adaptrum of beacons, not an integrated test with a WSD, though I’d love for this to happen asap.

“(even if they're illegal -- and folks really should read Parts 74.6 and 74.832 so folks understand that theaters are by and large illegal and unlicensed users of wireless microphones.”

Please believe when I say the entire non-broadcast, non-content production entertainment industry is aware of their [il]legal status regarding Part 74 operations.

“I'm very interested in finding ways to legalize these sorts of illegal users -- which is why I think it makes all the sense in the world to merge arts and cultural constituencies with public interest and consumer advocate constituencies.”

Strongly agree.

“As long as Broadway folks take the position that they have rights that they don't actually have, and position public interest groups and consumer advocates as their enemy,”

We’re/they’re not stating we have rights, rather we’re expressing grave concern for potential interference that will detrimentally affect the audio consumers pay a lot of money to enjoy at live, broadcasted and transmitted events.

“they're both creating enemies that don't exist and placing themselves into a position that will afford far less protection and negotiating power to protect their own interests.”

This I fear is the case with Shure and NAB, but please don’t completely bundle Broadway into that fold.

“Either way, this is certainly a discussion that would be fun to have over a few pints. I'm not sure if you're DC-based or visit often, but it would be great to get together, grab some cocktail napkins and see if we can't draft up a mutually agreeable position on this. I think we'd find that we're in agreement more often than one would expect.”

I’m based in NYC and of course welcome a meeting should you find yourself in this neck of the asphalt. I’m not scheduled to be in the DC area anytime soon, but will let you know if that changes. And make mine a strong stout please.

Henry -- some more thoughts...

You wrote:

Evans tested only interference potential to broadband DTV signals, not narrowband analog FM, and the two are completely different in terms of their interference susceptibility.

Correct -- at the time, we didn't know that wireless microphones were addressing the first major battle (where NAB said that devices couldn't work with DTV signals). Once we built devices that did that fine, the debate moved to wireless microphones. If things carried on another 6 months, I suspect we'd settle the issue of how to protect wireless mics just in time for a new "problem" to arise. One of the issues we're facing is a battle over where the goal posts are (they keep being moved around on us). I'm actually heading out to Shared Spectrum's laboratories today to get a demo of their most recent WSD technologies and discuss their capabilities. Avoiding interference with legal microphone users shouldn't be a problem (worse case scenario is that the venue uses a beacon like the one that Adaptrum just built -- their ex parte is in the 04-186 record).

You wrote:

While I certainly agree that legally both Part 74 and white space devices must not cause interference and must accept any, my only point is that WSD proponents are making claims that WSD *won’t* cause interference when there’s been no transmission tests to date, so such a claim is premature.

What I've been hearing is that WSDs can be built so that they won't cause interference and that they are exceedingly unlikely to cause interference under real-world operating conditions. If a WSD can ID an occupied channel it won't transmit on that channel -- it then becomes a question of designing technical specs so that transmitting on adjacent channels won't cause interference. Since this is a fairly straight-forward engineering problem (limiting OOB emissions), I think one is on fairly safe ground claiming that WSDs are exceedingly unlikely to cause harmful interference. The real hoop to jump through is determining how best to signal that channels that wireless mics are using are occupied -- especially given how many different types of mics are out there. But given the success of the tweaking that's been ongoing with the prototypes, it's clear that this is an entirely surmountable problem.

You wrote:

We’re/they’re not stating we have rights, rather we’re expressing grave concern for potential interference that will detrimentally affect the audio consumers pay a lot of money to enjoy at live, broadcasted and transmitted events.

Your concerns have been very much heard (and acted upon) by folks like myself and other key people working on the public interest side of things, within WIA, etc. As someone who has been actively advocating for continuing discussions with performance arts folk (and ran a venue for a number of years), I've been fairly vocal in my support of working with Broadway and its allies.

More importantly, the concerns that folks have raised have been an integral part of the public interest groups' positions for quite some time. However, when performance arts folks have weighed in at the FCC, they've often done so with remarkably blunt instruments -- the story that's being heard (regardless of the story that was meant to be told) is that these performance arts groups are, as illegal users, demanding protections they don't have a legal right to and, at the same time, advocating against white space devices.

I've had a remarkable number of private conversations with folks from various performance arts groups where they've stated that they're very much in favor of white spaces and are simply interested in ensuring that co-existence protects wireless mic use. But the public face has been perceived as fairly adamantly opposed to WSDs.

I actually think that Broadway's hands would be strengthened by working with public interest groups to both support WSDs *and* support wireless mic protections and the legalization of wireless mic use. It's a clear win-win and I'm at a loss why there hasn't been a lot more forward movement on this idea.

You wrote:

This I fear is the case with Shure and NAB, but please don’t completely bundle Broadway into that fold.

Agreed -- I've heard this from a number of folks in this arena. But what it really comes down to (in the FCC policy realm) is what's on the public record -- which is where the differences between the Shure/NAB position and Broadway/performance arts groups position are nearly non-existent.

As I mentioned, clarifying areas of concern and agreement would go a long way towards building bridges with both public interest folks and high tech firms. In the end, I actually think these constituencies are far closer in our goals than one would expect reading through the 04-186 proceedings -- what I would really like to see is a way to jointly address everyone's needs.

I can definitely round up public interest folks (and high tech folks if that's helpful) -- I know some folks have already talked with me about visiting. I'd be willing to go to bat to help formulate a joint statement to the FCC if there was interest on your side of things to do this. Bringing folks together on this issue would send a strong message to the FCC and help ensure that both performing arts and public interest groups get what they need from this proceeding.

Anyway, maybe it's time to take this conversation private -- feel free to drop me an e-mail if you're interested.

" 'I'm not worried about devices claiming extra channels were occupied since that's simply affording more protection; however, do you know which channels these were?'

I’ll get that to you when I return to my office on Monday."

The two channels that had neither usable TV signals or wireless mics operating within were 23 and 37. The Philips unit showed both these channels as available during the first sweep with all mics turned off. During the second sweep with mics on (in channels 26, 35, 39, 46 and 48), the Philips unit showed both 23 and 37 as occupied.

I have nothing against false positives per se, except that 1) it indicates very poor selectivity and 2) it's likely an indicator of other less than competent design parameters. If they can't get good selectivity and accurate math in a very large scale, cost no barrier test bed with an external full wave dipole antenna, what'll happen when the device is shrunk down to handheld size with an internal surface mount antenna and a price point attractive to the "millions of people on the wrong side of the digital divide"?

Or, let me pose my other concern: Lots of false positives keep subscribers from connecting. They get angry and drop the service or complain - alot. Manufacturers, already having product certification or type approval, decide to reduce sensitivity to ensure subscribers connect more often. My guess is they'll figure with millions of devices out in the marketplace, there's no way they can be recalled; they'll simply pay whatever meager fine the FCC levies, consider it CODB and count their profits. But that's just me.

As resources in all facets of our life (including technology) become scarcer, I think finding innovative ways to use what we have (and new ways to use previously unused frequencies or additional parts of technology pieces) becomes more important than ever before.  Equally important as technology creeps into every area of life beyond just “high-tech” areas (such as many formerly untouched areas of arts and culture) is making sure it actually helps rather than hinders that to which the technology is being applied.  Thanks for this article!  It certainly does raise some interesting questions. 

I've been following this issue marginally since it developed (and have worked with RF devices for my entire career).  While I have my own views on the topic, I think the biggest challenge to observers is to understand both sides of the issue without bias. 

One of the biggest problems concerning RF transmission is that, despite what some may claim, it is impossible to completely predict the a priori behavior of all receivers in a coverage area; one can only describe the statistical reliability of reception, and those statistics only come about a posteriori, i.e., after the devices have been deployed.  By that time, "Pandora's box" has been opened.

Broadcasters don't want their business endangered, and the free market wants access to spectrum.  By necessity, each proponent will of course attempt to justify why their position is correct, to the contradiction of the other's; and each party will display some extent of prejudice. 

The FCC exists to regulate spectrum interference, and is hoped to be neutral - and therefore an appropriate judge - in the matter.  But people are often swayed by politics, and that makes the issue complex, as always.

I am in DC and NYC on occasion, and would welcome an ale with either Meinrath or Cohen.

-agc

Mr. Cugnini,

    Please don't hesitate to contact me the next time you're in NYC. Where in northern NJ are you? I'm 45 minutes from the Meadowlands.

 Henry Cohen