Unfortunately, You Can't Make

the Wireless Microphone

Problem Go

Away by Taking a Different

Tack in TV White Spaces

There seem to be repeated rumors coming out of FCC that maybe they should take a different approach to utilizing TV "white spaces" by licensing them for broadband. Perhaps some think this will solve the wireless microphone problem painlessly - it won't.


TV white spaces are the inevitable result of TV broadcast licensing, especially when there is uneven terrain and uneven population distribution. There will always be places where there is no usable TV signal on a channel and were lower power use of that channel by other services is possible without interference. Under analog TV there was a lot more such white space due to the "UHF taboos" necessary to avoid neighboring channel interference to TV sets with mediocre selectivity. (FCC efforts in the 1970s to improve TV selectivity and decrease white spaces went down in flames due to broadcaster opposition.)


Wireless mics can use TV white space to provide a useful service, but in doing so inevitably use spectrum inefficiently compared to other possible users of white space. Why? Wireless mic use is intermittent in both space and time and only uses a tiny fraction of the space/time/spectrum resource made available by TV white spaces. Hence use is heavy in the Broadway theatre district of Manhattan and in a few other theatre districts. Use is heavy near churches for a few hours a week. But reserving TV white spaces for the exclusive use of wireless mics denies the spectrum to other that can use it much more intensely.


The current wireless mic mess is a result of both benign neglect of FCC towards this sector and aggressive merchandising by mainly Shure, Inc. to large numbers of users ineligible under current FCC rules to use them. (The hypocrisy of the TV broadcasters for opposing Part 74 eligibility for the churches and theatres for years, if not decades, and then becoming Shure's "best buddy" during Docket 04-186 is certainly a case of "strange bedfellows".)


I have repeatedly written here that "wireless mics are a legitimate use of spectrum (that) deserves more from FCC than benign neglect that allows most users only criminal spectrum squatting" . Yet FCC has taken no action even on the relatively simple issue in Docket 08-166 of evicting wireless mics from the spectrum that is now licensed to others after the DTV transition, let alone the more complex issue in Docket 08-167 of whether action should be taken against anyone for flaunting the Commission's rules and creating a de facto reallocation of spectrum.


The only way to avoid the inefficient use of white space that would result from preserving the present squatting of large numbers of users is to move towards a new method of serving wireless mic needs that does not give them exclusive, hence inefficient, spectrum. Let me note that CMRS licensees already have the regulatory flexibility offer femtocell-like systems that transmit wireless mic signals on CMRS spectrum without interconnection to the public network - one way connections from the microphone to the theatre/church audio panel. While the microphones and analog-to-digital convertors (DAC) used in cell phones are not of sufficient sound quality for many wireless mic applications, there is enough CMRS bandwidth available now to permit adequate quality with better mics and DACs. If the CMRS crowd really wants 800 MHz below 3 GHz , maybe it should seriously think about helping FCC by proposing a practical alternative to the wireless mic impasse.


Another approach to solving wireless mic spectrum problems is to move this use to another band where it will have a compatible spectrum sharing partner. Since wireless mics are a distinctly short range service, such sharing should be possible. For starters, the 1435-1525 MHz aeronautical telemetry band might be considered.


But letting wireless mics just sit in white spaces will inevitably cause problems for both the current policy adopted under Docket 04-186 and any alternative path the Commission might go down.

CTIA, NENA, APCO, and NPSTC Ask FCC to Act on Wireless Microphones and 700 MHz

On 2/23 CTIA - The Wireless Association®, the National Emergency Number Association ("NENA"), The Association of Public-Safety Communications Officials - International ("APCO"), and the National Public Safety Telecommunications Council ("NPSTC") filed a joint letter with FCC in WT Docket No. 08-167 asking it to act on the issues of wireless microphones' continued use of 700 MHz.

(Oddly the letter is not on the CTIA website even today, but was reported by FierceWireless.)

The letter stated,

"Harmful interference from unauthorized low-power devices operating in the 700 MHz band threatens to prevent licensees from realizing the benefits to public safety that the 700 MHz band promises. We understand that there is an item currently before the Commission to address low-power devices in the 700 MHz band and urge you to take action to curb the harmful use of these low-power devices.

It is of critical importance that low-power auxiliary devices do not cause harmful interference to critical communications - and the commercial communications that enable ordinary Americans to reach public safety in their moments of need. As both public safety and commercial licensees begin to utilize spectrum from broadcasters who have completed their digital transition, we ask that the Commission take action to clear the 700 MHz band of unauthorized low-power auxiliary users. By clarifying in an Order that low-power auxiliary devices must not interfere with authorized public safety and commercial licensees, and that those devices must accept all interference from licensed users, the Commission sends a strong signal to all users of these devices that the public safety benefits of the 700 MHz spectrum outweigh any - licensed or unauthorized - use of the band."

The joint parties then said they

"urge the Commission to require that operation of all low-power auxiliary devices in the 700 MHz band cease no later than one year from the adoption of an Order and issue a Consumer Advisory informing the public. Additionally, in order to speed the deployment of public safety and commercial systems in the 700 MHz band, the Commission should require low-power users to cease operation within 60 days of notice that a licensee intends to initiate or change its wireless operations such that the low-power devices will likely cause interference."

As we pointed out previously, this 60 day issue - originally proposed by NAB, MSTV and Shure - has the practical problem that almost all wireless microphones in use are illegal and hence not in any public database. (Perhaps Shure has such a database internally and might be willing to share it in exchange for immunity from criminal prosecution of their clients?)

So far Shure and fellow travelers have not addressed the points raised in this joint filing.

700 MHz and Wireless Mics:
No Resolution Yet

Readers may recall that on November 28, 2007 we published a posting entitled "700 MHz Auctions About to Start - But FCC Hasn't Evicted Wireless Microphones Yet". Well, in the past 13+ months:

• FCC has finally proposed evicting them,
• NAB, MSTV, and Shure have asked for an extended phase out period including public safety and other licensees being required to notify wireless mic users to vacate - but not giving the slightest hint how to find this unlicensed and lawless crowd; and recently
• A coalition including Alcatel-Lucent, APCO, AT&T, CTIA, Motorola, NENA, PISC, Qualcomm, and Verizon Wireless wrote FCC on this issue.
  

The coalition letter urges

"the Commission to take swift action to ensure that the use of low power auxiliary stations (e.g., wireless microphone systems) in the 700 MHz band does not threaten the future use of important spectrum that is being made available with the DTV transition."

So a lot has happened since SpectrumTalk first pointed out the problem, but nothing has been resolved. Maybe when FCC has to deal with deciding between pleasing the broadcasters and pleasing public safety it really doesn't know what to do?

Wireless
Microphone Update:

The Twisted Logic of NAB and MSTV - Now Locked
in Conflict with APCO and CTIA

Faithful readers will recall that we have talked a lot here about the saga of wireless microphone use in UHF-TV channels. While we have discussed that most wireless microphone use is illegal, we have also stated that "wireless mics are a legitimate use of spectrum (that) deserves more from FCC than benign neglect that allows most users only criminal spectrum squatting. (3/10/2008)

While CTIA and the cellular establishment were ignoring the wireless mic issue and seeing the TV whitespace docket (04-186) as a way to covet more spectrum and while the public safety establishment was asleep on this issue, concentrating on the D block, SpectrumTalk reported a year ago that FCC had still taken no action to evict legal, let alone illegal, wireless microphones from the 700 MHz band (TV channels 52-69) -- even as they were giving part of the band to public safety users for critical needs and auctioning off the rest for billions. (11/26/07)

Well, finally FCC woke up after the PISC petition/complaint. In August FCC released an NPRM/Order in Dockets 08-166 & 08-167 addressing the petition and announced (at long last) "that the Commission’s Enforcement Bureau has initiated an investigation relating to the marketing practices of various manufacturers of wireless microphones." (However, there is no visible sign of that investigation or its results.)

The order part of the NPRM/Order was amusing. It stated,

"In light of our tentative conclusion above not to permit the operation of low power auxiliary stations on 700 MHz Band frequencies (698-806 MHz) following the end of the DTV transition, we also find that continuing to accept new license applications for low power auxiliary station licenses that involve the operation of such stations on this spectrum after February 17, 2009 would impair the objectives that we are proposing in this proceeding." (para. 23)

The problem here is that the vast majority of all users here are not licensed since their use is illegal. Therefore, stopping new licenses will have no impact. Indeed, it is unlikely that any new licenses are issued normally. There are only 156 current legal licenses in the whole country for wireless microphones and other low power auxiliary equipment in the 700 MHz band. (It is likely that many broadcaster wireless microphone operators who are eligible for licenses have never applied for them, why should they if no one else does?)

How did we get into this mess? The comments of Nady Systems, Inc. are both candid and informative (a refreshing change from their self serving competitor, Shure., Inc.):

"The FCC's Policy Toward Unlicensed Wireless Microphone Use Was
Tacit Allowance and Benign Neglect

Throughout the 1980s and early 1990s. John Nady several times raised with FCC officials the question of whether FCC regulations needed changing so that the growing class of wireless microphone users who were ineligible to be licensed under the existing rules could become officially authorized. The officials told him that there is no need to change the licensing regulations - a cumbersome process - because since the FCC has not received complaints of wireless microphone interference with TV reception unlicensed use is not a problem. For over thirty years. the FCC has known about unlicensed wireless microphone use in the TV spectrum for purposes not authorized by regulation and has tacitly allowed that use to continue. For example, in opening up the 171-216 MHz TV spectrum to wireless microphones, the Commission noted '..the need for wireless microphones used in special events coverage and in dramatic presentationshaving a large number of performers:') The Commission stated: 'We are confident that groups other than broadcast licensees can use these frequencies responsibly. obtaining the benefits of such use while being aware of the interference possibilities associated with it.' In 1992. the Commission observed, 'commentators argue that experience with wireless microphones in the TV spectrum has shown that devices of this type end up being used by all sorts of people in places where they are not authorized by the rules')

The FCC's policy of benign neglect toward unlicensed wireless microphone use in the TV spectrum has allowed the wireless microphone industry to develop technologically, fill a market need, enabled prices to come down as a result of volume production and opened up the benefits of wireless microphones to professionals not limited to the TV radio-motion picture industry."

There is an important moral here: when the Commission focuses its efforts almost entirely on petitions from major parties and ignores actual technical and market developments, its rules drift farther and farther away from reality. "Rule maintenance" is needed to prevent this, but that is not a sexy topic at FCC and gets little management attention. Focusing policy resources on "buying IBM" is less risky for managers at FCC. But technology and the communications market move at "Internet speed" while government regulations move at "government speed".


Which brings us to the 10/3/08 joint comments of MSTV and NAB. Having aligned themselves with Shure in Docket 04-186, MSTV/NAB continue to follow Shure's policy of protecting its lawless user base even though NAB usually advocates strict compliance with Title III licensing. The really twisted logic is at the very beginning of the comments, not hidden in the middle or an obscure footnote):

"MSTV and NAB propose that wireless microphone operation on a specific frequency and geographic area end upon the earlier of (1) sixty days prior to the date on which the 700 MHz wireless entrant intends to begin service, per a notice sent to the affected wireless microphone licensees, or (2) February 2012.
...
Under the plan proposed by MSTV and NAB, any commercial wireless or public safety licensee will be able to ensure that its frequency is cleared of wireless microphone use prior to beginning service — even if that date of first service is February 17, 2009." (emphasis added)

Questions for MSTV/NAB: As has been said repeatedly in both 04-186 and 08-166/7, without any contradiction at all in the public record, the vast majority of wireless microphone users are unlicensed and not eligible for licenses. Indeed, they are in criminal violation of 47 U.S.C. 301. No one knows who they are or where they are. (In the past NAB has opposed expanding Part 74 eligibility so NAB is not exactly an innocent party here.) So how does the public safety licensee or auction winner find these people to give them 60 day notice to vacate?

But MSTV/NAB are not just worried about the illegal users. They add,

"Adoption of such a short timeframe for licensed wireless microphones to transition to other bands inevitably will result in service disruptions. Re-tuning equipment to cease operation in the 700 MHz band will cost on average $50,000 to $75,000 per station. Stations’ budgets, which already have been completed for the year, do not account for this expense; station resources have been allocated to complete the digital television transition. Even if stations could afford to purchase new equipment to operate in different bands in such a short timeframe, manufacturers may not be able to meet the unexpected demand. Of course, a significant increase in demand is also likely to add to the cost of obtaining new or re-tuned equipment."

Dane Ericksen, a former FCC enforcement official and prominent broadcast consultant, blasts away all the MSTV/NAB arguments (as well as the wireless mic interests') in his reply comments. ( Guess no more consulting work for him from MSTV or NAB. They are both reputed to demand "loyalty" from their consultants.)

Did not MSTV/NAB members, of all people, know that the DTV transition was coming? Had they read about the 700 MHz auction? Even their favorite magazine, Broadcasting & Cable, wrote about the 700 MHz auction!

Are MSTV/NAB members paupers? Maybe NTIA should issue special coupons for low income broadcasters to subsidize their wireless mic replacements?

Please explain under your plan how "any commercial wireless or public safety licensee will be able to ensure that its frequency is cleared of wireless microphone use prior to beginning service — even if that date of first service is February 17, 2009."

We promise to post without editing, any reply from broadcasters and wireless mic interests (and others) as long as the wording is appropriate for current FCC broadcasting content limits. (Fleeting expletives OK.)

This 700 MHz issue has now become an "irresistible force/immovable object" topic as CTIA and APCO ("APCO urges the Commission to take aggressive steps to eliminate those nonconforming uses as quickly as possible") have staked out opposing positions. MSTV and NAB usually get their way at FCC in practice, but this time they may have "bitten off more than they can chew".

Wireless Microphones:
FCC Finally Starts
Seeing Reality

Yesterday FCC released a Notice of Proposed Rulemaking and Order in Docket 08-166 dealing with the wireless microphone issue. [Washington Post article.]

The gist of the document is given below:

"2. In this Notice of Proposed Rulemaking and Order (“Notice and Order”), we consider broadcast low power auxiliary stations, which have been permitted to operate on TV Channels 52-69 in the 700 MHz Band, as well as in several other bands, on a secondary non-interference basis. In the Notice of Proposed Rulemaking (Notice) below, we tentatively conclude to amend our rules to make clear that the operation of low power auxiliary stations within the 700 MHz Band will no longer be permitted after the end of the DTV transition because such operations could cause harmful interference to new public safety and commercial wireless services in the band. We also tentatively conclude to prohibit the manufacture, import, sale, offer for sale, or shipment of devices that operate as low power auxiliary stations in the 700 MHz Band. In addition, for those licensees that have obtained authorizations to operate low power auxiliary stations in spectrum that includes the 700 MHz Band beyond the end of the DTV transition, we tentatively conclude that we will modify these licenses so as not to permit such operations in the 700 MHz Band after February 17, 2009. We also seek comment on issues raised by the Public Interest Spectrum Coalition (PISC) in its informal complaint and petition for rulemaking (“PISC Petition” or “Petition”).

3. In the meantime, in the Order below, we impose a freeze, effective upon release of this Order, on the filing of new license applications that seek to operate on any 700 MHz Band frequencies (698-806 MHz) after the end of the DTV transition, February 17, 2009. In addition, we impose a freeze on granting any request for equipment authorization of low power auxiliary station devices that would operate in any of the 700 MHz Band frequencies. We also hold in abeyance, until the conclusion of this proceeding, any pending license applications and equipment authorization requests that involve operation of low power auxiliary devices on frequencies in the 700 MHz Band after the end of the DTV transition.

...

22. We seek comment on the various elements found in PISC’s Petition, particularly to the extent that we are not addressing those elements elsewhere in this Notice and Order. We note that the Commission’s Enforcement Bureau has initiated an investigation relating to the marketing practices of various manufacturers of wireless microphones. "

So almost 7 months after the start of the 700 MHz auction that produced income of $19 billion, FCC is finally getting around to kicking the wireless microphones out of the band they have sold to others for use starting in 2/09, less than 6 months from now.

But don't expect immediate action. The NPRM only proposes to stop legal use of channels 52-69 for wireless microphones. But since most use is already illegal the real impact is questionable. It proposes to stop approving new models and freezes all pending applications for equipment authorization, but previously approved models can be imported and sold by the thousands pending further action.

As quoted above, it also announces the opening of an investigation into the marketing practices of the wireless microphone manufacturers.

It does not raise the issue of innovative approaches to serving the legitimate needs of wireless microphone users such as:

• new technology like the Sony digital wireless microphone sold in the UK or
• the Audio-Technica UWB wireless microphone
• using a coordinator/band manager for all wireless use who has the incentive to find ways to use spectrum more efficiently as the FCC's UK counterpart, Ofcom, has done
  
• or access to sharing new bands, as Europe is considering for L band.

Shure Cleans Up Its Act - A Little Bit

In a previous post I reported that Shure was ignoring public safety use of TV channels 14-20 in making recommendations to their generally not legally eligible customers for their illegal use of UHF spectrum. A mutual acquaintance discussed this with Shure and reported back that it was an unintended software bug and that they had intended to warn the illegal users, i.e. their customers, to avoid public safety spectrum. He also reported that Shure would correct this specific problem.

The good news is that Shure has acted as promised.

Shure's listing of Chicago UHF spectrum use in channels 14-51

Above is the latest data from Shure's "Wireless Frequency Finder". (See, who needs Chairman Martin and the FCC?) In the case of Chicago, channels 14 and 15 are clearly marked as used by "safety" just like 47 CFR 90.303 says. Perhaps APCO will give Shure an award for this support to public safety?

Indeed Shure goes beyond this if you look a little higher in the spectrum.

Shure's listing of Chicago UHF spectrum use in channels 29-69

Now Shure even advises this customers that channel 68 and 69 have been "reallocated for public safety". Shure also advises that US customers avoid purchasing "UA band" (782.125 - 805.750 MHz) systems although in 2004 they were hyping this band. (Let's ignore the issue that Canada will use the same public safety block as the US and there is no guidance for Canadian clients - Industry Canada will have to handle that one alone.)

But why channels 68 & 69?

Upper 700 MHz band plan

Above is the current 700 MHz band plan. You can see why Shure's UA band is such a problem. Is Shure offering a deal to those who were tricked into buying them in recent years? But why the focus on channels 68 and 69? Note that there are 2 public safety blocks here in the former channels 62-64 and the former channels 67-69. Note also that the famous "D block" covers the remainder of channels 62 and 67 and, if the FCC ever resolves the auction issues of this band and public/private sharing, will carry public safety traffic at times of heavy load. Why are only 68 and 69 identified as worthy of special attention?

Oddly, on another part of its website Shure does say that "the FCC has reallocated four UHF TV channels for use by Public Safety stations" but doesn't mention what they are. Also, if D block is included there are 6 channels that will be used by public safety. But in any case, all wireless mics (legal and illegal) should be totally out of channels 51-69 by February!

A non-public safety issue I noticed in the Shure tables above deals with channel 55. Note that Shure does not identify any present TV use of it in Chicago. They're right! However, did Shure miss the news in Wikipedia that Qualcomm has a nationwide license on channel 55 for its MediaFLO service (which is resold to consumers under other names by AT&T and Verizon Wireless)? Qualcomm MediaFLO is secondary to TV stations until next February but is now operational in the cities listed below:
Note that MediaFLO is operational in Chicago on channel 55 as well as a lot of other cities. While it is secondary with respect to licensed TV stations, I am reasonably certain that it is primary with respect to noneligible/illegal users of their spectrum. It also is a potential source of interference to wireless microphones if they are near a transmitter site. (And wireless microphones are a potential source of interference to consumers using MediaFLO-based services.)

Readers interested in more news on wireless microphones are referred to the recent post on the PISC complaint that alleges that not only is Shure's customers' use of these frequencies illegal but that Shure itself is acting illegally

"for willfully and knowingly marketing and selling wireless microphones to unauthorized users for ineligible purposes in violation of Part 74, Subpart H, and for engaging in deceptive advertising practices designed to persuade ineligible users such as houses of worship, theaters, corporate event venues, and members of the general public that they could legally purchase and operate wireless microphones operating on vacant broadcast UHF Channels without a license and for purposes prohibited by the Commission;"

and to my recent FCC filing pointing out the CEPT, the European spectrum regulator, has proposed to move wireless microphones to an entirely new band as part of their digital transition.

As I have said before, wireless microphones are a legitimate use of spectrum and deserve more from FCC than benign neglect that allows most users only criminal spectrum squatting. I have advocate a responsible solution to this mess; PISC includes with their complaint a responsible proposal for solving the problem; but Shure seems to just demand the status quo. FCC is strangely silent on the wireless microphone issue other than considering offers of venues, many of which are illegal users, for Docket 04-186 testing of wireless microphone detection.

My client, Adaptrum, pragmatically also supports protection of wireless microphone users but has told FCC that a combination of safe harbors (for small users) and well placed beacons would be more effective than the passive detection advocated by other Docket 04-186 proponents.

Update

I just discovered that the National Public Safety Telecommunications Council (NPSTC) wrote Chmn. Martin on June 30, 2008. The letter stated,

• The Commission should take specific action to ensure that all
  manufacturers cease certifying, marketing and importing wireless microphones and
  similar devices capable of operating in the public safety 700 MHz band spectrum
• NPSTC recommends the Commission expeditiously initiate an aggressive and rational transition within which users must find other solutions for any microphones operating on the 700 MHz public safety spectrum
• Unlicensed microphones present a different situation. Legally, unlicensed
  wireless microphones already have no authority to operate.
  
• (The Commission should) expeditiously issue a Public Notice targeted toward wireless microphone manufacturers and dealers advising of the transition in use of the 763-775/793-805 MHz spectrum and need to cease unlicensed operations in those band segments.

In view of the great apparent interest in public safety at FCC it is amazing that no action has been taken on any of these points in the more than a month since the letter was sent.

Oddly, NPSTC did not address the issue I have raised about the legal ambiguity of wireless microphone use of land mobile spectrun in TV channels 14-20.

New Wireless Microphone Complaint and Petition

This week the Public Interest Spectrum Coalition filed with FCC a complaint about the massive marketing of wireless microphones to users who could not legally use them - creating de facto allocations and service rules without the benefit of policy deliberations and consideration of the long term implications.

This petition results, in part, from some work I did for the New America Foundation, a PISC member. The concepts are also related to my March 10, 2008 post entitled "Wireless Mics are a Legitimate Use of Spectrum:They Deserve More from FCC than Benign Neglect that Allows Most Users Only Criminal Spectrum Squatting".

The basic points of the FCC filing are:

• Begin an investigation against Shure, Inc., and the other manufacturers listed in the informal complaint, for willfully and knowingly marketing and selling wireless microphones to unauthorized users for ineligible purposes in violation of Part 74, Subpart H, and for engagingin deceptive advertising practices designed to persuade ineligible users such as houses of worship, theaters, corporate event venues, and members of the general public that they could legally purchase and operate wireless microphones operating on vacant broadcast UHF Channels without a license and for purposes prohibited by the Commission;

•Grant a general amnesty to all unauthorized users of wireless microphones deceived by the
illegal and deceptive marketing of manufacturers, permit use of the illegal equipment on a
going forward basis until the Commission authorizes the proposed GWMS, and require those
manufacturers that engaged in illegal marketing to migrate the unauthorized users of Part 74,
Subpart H equipment to the new GWMS by replacing equipment authorized for Part 74,
Subpart H with equipment authorized for use in the GWMS;

•Immediately reclassify all licensed wireless microphone systems operating pursuant to Part 74, Subpart H as secondary to all advanced wireless service (AWS) and public safety systems authorized to operate on television Channels 52-69 following the shut off of analog television transmission;

• Order that manufacture, sale, and advertisement for sale of wireless microphone systems operating on channels 52-69 cease immediately; and

• Create a new “General Wireless Microphone Service” (GWMS) licensed by rule pursuant to Section 307(e) to operate on vacant broadcast UHF channels below Channel 52 on a secondary basis to broadcast licensees and individually licensed wireless microphone systems, and authorized on a primary basis to operate on the 2020-25 Band currently authorized for broadcast ancillary service (BAS) and under consideration for reallocation in Docket Nos. WT 07-195, WT 04-356 (“AWS-2/AWS-3 Proceeding”).

It has always amazed me that in a law and order-oriented Republican administration this lawless behavior has been tolerated even when it involves the illegal and dangerous use of public safety spectrum. (In the case of immigration reforms, don't most Republicans think that those who have violated the law should not be given amnesty and should go to the "back of the line" with respect to benefits? In this case, the "liberal" members of PISC are at least consistent with the liberal view of immigration issues. It will be interesting to see how Republicans view the issue.)

Indeed, it is amazing that this complaint comes from PISC, not CTIA or its cellular behemoth members that have recently spent billions for the spectrum that Shure encourages their customers to use and not from APCO that hounds the FCC for more spectrum but has ignored protecting the spectrum from such intruders. (While there may not be a documented case of wireless mic interference to public safety in the FCC records, we all know that public safety systems frequently have marginal repeater coverage inside buildings. (Remember what happened at the World Trade Center when the firemen couldn't get receive the order to evacuate?) When the downlink signal is marginal, small cochannel signals can easily cause interference. So CTIA and APCO members might want to ask their trade associations why they have been ignoring this spectrum squatting for so long.

Discussion in Harold Feld's blog including exchange with Henry Cohen, an engineer active in Broadway use of wireless mics.

AP story

Chicago Tribune story. Includes this discussion of Shure's views,

Shure spokesman Mark Brunner said the company is aware of the potential interference problem from the digital transition and hasn't sold products for that spectrum since late 2007. [Wow - they stopped in the past year. Maybe they finally read something in USA Today about the 700 MHz auction! Maybe news travels slowly "outside the Beltway? What have they told customers that bought this equipment? The world wonders. - MM]

As for the broader issue of how so many unauthorized users were allowed to purchase wireless microphones, Brunner said technological advances and market practices of the last several years simply overtook the outdated FCC rules.

"Those rules were written several decades ago, when wireless microphones were a bit more crude than they are today. … Over time, no interference complaint has really resulted," Brunner said. "The technology got better and more industries decided they were interested in using these products. … The rules were never really updated to reflect that."

Did it ever occur to Shure to ask FCC to change its rules rather than selling hardware to users who use of it would be in violation of criminal law and might endanger public safety where the FCC's tolerance of interference risk is rightfully near zero?

Wireless Microphones and
Docket 04-186: Two Different Viewpoints

On May 1st, the Sports Technology Alliance, a trade group consisting of the major professional sports leagues and ESPN, submitted an ex parte filing to FCC on why the FCC should reject the TV whitespace proposals of Docket 04-186 because of the threat of harm to the production of live sports events or the possible resulting requirement that using beacons to protect legal wireless microphone use "would result in significant additional expense to acquire new equipment merely to enable existing equipment to continue to function." Presumably the "existing equipment" they mention is the analog FM FDMA equipment that is being replaced now in almost every other radio service by more efficient equipment.

To bolster their technical points, this group has hired Harbour Group, a Washington DC PR firm to explain the advantages of the status quo. Harbour's website explains their approach to advocacy:

“We have helped clients sharpen their messaging and delivery to provide support to their allies and put pressure on opponents, shaping the policy environment... Managing the public policy issues that can affect an organization’s success starts with identifying and prioritizing challenges. We conduct thoughtful research, target key constituencies, build successful alliances and mobilize supporters. Our collective backgrounds provide a powerful combination of expertise and experience that allow us to help shape policy development and deliver results.”

Oddly, Harbour has never mentioned why these multibillion dollar clients need continued cost free access to spectrum on demand anywhere in the US even if it denies the use of the spectrum to others and why they cling to using dated FM FDMA technology when even your neighborhood taxi is transitioning to more efficient technology.

SpectrumTalk welcomes Harbour Group to the fray and looks forward to the "pressure" they promise. However, the wireless microphone community might do better hiring technical advisers to see what their technical options really are rather than clinging to technical and regulatory approaches of the past.

Marcus Spectrum Solutions LLC has filed with FCC today a response to the Sports Technology Alliance. Readers are encouraged to compare the two viewpoints and comment on them. While I nominally "moderate" comments on this blog to prevent spam, all comments received will be posted below except those that are clearly spam or contain words not fit for broadcasting. I suppose Harbour Group would not suggest that the other side be as open.

A Wireless Microphone Manufacturer's Approach to Spectrum Management

In Docket 04-186 (TV Whitespace) the wireless microphone community has been making numerous complaints about how they can not be subject to any interference because they are such a vital service. Of course, the vast majority of present wireless microphone users are not eligible for licensed under Part 74, Subpart H so such use is actually a criminal violation of 47 USC 301. But setting that aside for the moment, let's see how responsible they have been. Below is a web page I downloaded for Shure's Wireless Frequency Finder website. I have made several annotations.

(Click on any of the images in this post to get a clearer version of the information shown)

First, next to the letter A is the following quote:

"As a rule, a wireless system should NOT operate on the same frequency as a local TVstation. The signal strength of a television transmission is many times stronger than that of a wireless system, and will result in interference."

I note that "rule" is not capitalized, so I assume that Shure is not referring to FCC Rules. You see the reason you should not pick an active local TV channel is that you might get interference. Shure apparently isn't concerned that TV viewers might get interference. Shure also isn't concerned about interference to weak distant TV stations, the problem that MSTV keeps complaining about for the proposed white space devices. Why is MSTV so worried about cognitive radio-based WSDs and oblivious to the present illegal use of UHF spectrum by "dumb" wireless mics?

Next, near the letter B, we have the following quote,

"Shure wireless microphones and PSM systems designed for use in the United States operate on standard VHF (TV channels 7-13, 174-216 MHz) and UHF, TV channels 14-69, 470-806 MHz, frequencies."

470-806 MHz? Does that sound familiar? Doesn't that include the frequencies that FCC
just auctioned off for $19B and AT&T and Verizon expect to start using in 306 days? Doesn't it include blocks that have been allocated to public safety? Did Shure forget to tell its customers? Perhaps they didn't read the newspapers about the auction? What are their customers really expecting? When is Shure going to urge them to move out of these 700 MHz channels? Note that the whole tone of the "spectrum finder" is that users should listen to Shure and just ignore FCC and everyone else.

Then I entered the FCC's ZIP code, 20554, in the Shure "frequency finder" and asked for frequencies in the DC area. Here are the results:

Well at least Shure does not recommend the frequencies that have been auctioned. But wait, isn't there something special about channels 17 & 18 in the Washington DC area? Weren't they allocated for TV Land Mobile Sharing in Docket 18262 in the 1970s?

Pulling out my brand new copy of 47 CFR I look up 90.303. Voila, in the Washington area 17 & 18 are land mobile public safety channels!

So I went to ULS and looked up the specific use of channels 17 and 18 in the DC area. Above is the list of 28 public safety agencies in the Washington area that use these frequencies. Did Shure ask them if it was OK for illegal nonlicensed users in a band subject to mandatory licensing to share their frequencies?

How could Shure have missed that? If Shure thinks sharing with public safety is so easy, why don't they file a petition and see what APCO thinks about it?

I have written previously that wireless microphones are a legitimate use of spectrum and that FCC should accommodate them in some way, but not necessarily with the same obsolescent technology forever and not necessarily in the same valuable spectrum that they use inefficiently (in terms of time and space availability) if they exclude all others. But the wireless microphone crowd should start acting responsibly first, not just urging their customers to squat on all sorts of frequencies including public safety frequencies.

Considering the lawless, reckless nature this group has shown, it is amazing that established trade groups like CTIA, NAB, and MSTV are all pandering to them. Normally these groups protect their own interests by stressing the need for compliance with FCC regulations, not explicitly condoning violations of them.

Wireless Mics are a Legitimate Use of Spectrum:
They Deserve More from FCC than
Benign Neglect that Allows Most Users
Only Criminal Spectrum Squatting

My former FCC boss, Dale Hatfield, used to say "if you are looking for interesting new ideas in spectrum policy, look what people are doing illegally and legalize it."

Well most wireless microphone use at present is illegal, a point that many people like to ignore - like the elephant in the room. Why are they illegal? Most wireless microphones in the US are physically Part 74 (broadcast auxiliary) devices operating in UHF TV spectrum in "white space channels" and require licenses. Only those industries specifically enumerated in Part 74 are eligible for such licenses and these are basically only NAB members and Hollywood moguls - all of whom have effective lobbyists in Washington. It is a cozy arrangement born in a different era of both technology and spectrum policy but it is a bad anachronism.

How did we get there?

In ancient history there was only analog television in UHF spectrum. The "UHF taboos" that resulted from both NTSC technology and 1953 estimates of how well future production TV sets could reject signals on nearby channels became self fulfilling prophecies and resulted in only 1 out of 6 channels being used in a given city. There was always tons of white space under this regulatory scheme. The "club" of broadcasters in a given city knew each other well and could work out deals to use this white space in support of their operations without interference. They sought and received FCC blessing for this exclusive use, although at some point Hollywood weighed in and became eligible also. Live theater productions, live concerts, churches, and conference centers are not eligible under Part 74 so their only legal options are low powered unlicensed systems that are secondary (and hence have greater risks of receiving interference) or Part 90 systems with complicated licensing requirements that probably have license transaction costs that exceed hardware costs in many cases.

Some unethical manufacturers and their dealers took advantage of this scenario and started marketing Part 74 wireless mics to noneligibles and "fuzzified" the legal issues. One even has on its website a "Wireless Frequency Finder" to help its customers find frequencies to use illegally. Apparently the FCC has turned a blind eye to this situation for years.

Lord Nelson raising his telescope to his blind eye in the Battle of Copenhagen

That was then, this is now

All of this was tolerable when spectrum was not in great demand, the dominant spectrum policy model was "command and control", there were few technical options for other use of the this spectrum, and there was plenty of white space. But that is all obsolete or becoming obsolete. Even as I write this the 700 MHz auction is winding down and next year TV channels 52-69 will be in the hands of new licensees who will expect to use them after a multibillion dollar auction. The NPRM in Docket 04-186 proposed 3 different options to use white space for broadband distribution in both urban and rural areas. While the broadcasters question the listen-before-talk option and have dragged everyone into obscure testing issues as a delaying tactic, the other 2 options are still on the table without significant objections.

The same wireless mic manufacturers who created the present lawless situation want the FCC to kill off the 04-186 proposals and allowed endless illegal squatting of their customers. The basic problem is that this would result in negligible overall use of a valuable resource: In the best circumstances the spectrum would be used heavily in the Broadway theater district, near megachurches on Sundays, and on the Las Vegas Strip. In terms of space and time, overall spectrum use would be negligible and it would be denied to all other classes of users.

The new technology proposed in 04-186 would result in much greater spectrum user and benefit to both the economy and society, but this should not mean that wireless mic users should be "thrown to the dogs". The users of wireless mics perform valuable are entitled to spectrum access, but access consistent with the current concepts of spectrum policy. They seem to demand continued exclusive access to "free spectrum" - even for clearly commercial operations. Guys, that is not the current era of spectrum policy.

Options for the future

But FCC should find a way to legitimize spectrum access for these users. Keeping them in the UHF-TV band will deny this spectrum to more valuable users but just as FCC relocated hospital-based medical telemetry out of this band into other bands where sharing was feasible, it should enter into a dialog with the wireless mic community (amnesty?) to find new spectrum home(s) where wireless mic use can share with other users on an interference free basis. Maybe there is a need for a coordinator who will charge fees like in the UK. (JFMG is the Ofcom-designated coordinator what what is called "PMSE" in UK-speak.) Unlicensed use and Part 90 use remains an option for users with modest requirements. Audio-Technica, a major supplier, has invested in and developed high reliability ultrawideband-based systems that can

Audio-Technica UWB-based wireless microphone system using MSSI's technology

satisfy the needs of users with needs for less than 14 units in a theater and can live with 12 kHz upper audio range - adequate for many users, but not opera. (This appears not to be a basic technical limit, but rather problems of an initial design of a niche product that uses off the shelf components.) A previous post here described how a AWS (3G) spectrum-based service could serve upper end users with high density and high audio quality requirements. Yes, it would result in increased costs for spectrum access. But that is the past 20 years of spectrum policy in the US and many other countries.

Finally, one problem the US wireless microphone manufacturers face is that they are relatively small firms with niche markets and do not have a good R&D base or volumes that easily justify custom integrated circuits. Thus they tend to stay with the existing technology and not press the margins to get new products. Thus they also are spending money on lawyers to press the FCC rather than innovating - like the medical telemetry people did when they noticed the same problem with the TV band. Ausio-Technica, as mentioned above, stands out as a recent innovator because they contracted with Multispectral Solutions (MSSI) of Germantown, MD for their new UWB product. They didn't spend all their money on lawyers!

Conservative wireless mic companies watch out! The problem isn't just Docket 04-186, Sony is entering your field too with new technology. Surf over to www.sonybiz.net/go-digital and you will see that Sony believes that digital will work for wireless mics and has entered the UK market. Fortunately for the not so nimble US manufacturers the present Sony models only work in 798-862 MHz and can't be used (legally) in the US market except in a small segment that will disappear in 11 months. But it wouldn't take much to move these to another band other than UHF-TV. Marrying the Sony analog-to-digital conversion technology to 3G/AWS cell phone technology should also be straightforward.

But the key issue is that FCC is not now considering any other options for wireless mics at the moment. The status quo is an inefficient anachronistic use of valuable spectrum and will have real problems next year when the 700 MHz auction winners claim their spectrum.

Possible options that should be examined should include the possibility of opening a new band, other than UHF TV. that is more compatible with sharing with the wireless mic industry as it actually exists today along with use of more efficient technology than the current de facto monoculture of FM. The demands of the wireless mic users that the new spectrum access should have no cost should be considered but should not be treated as a "non-negotiable demand". UK wireless mic users pay for access so there is a relevant precedent. The longer FCC ignores this issue, the more difficult it will become.

================================
Harold Feld has published an interesting follow up to this post entitled "700 MHz Aftermath: Verizon, AT&T & the $16 Billion Termites"

700 MHz Auction About to Start - But FCC Hasn't Evicted Wireless Microphones Yet

In Docket 04-186, the "TV Whitespace" rulemaking, there has been a lot of discussion about wireless microphones. These are devices supposedly used only by TV broadcasters and other broadcast industry eligibles defined in 74.832. Of course, most users are other audio-visual operators whose use is illegal. Indeed, today I spoke at IEEE Globecom and used a Shure wireless microphone operating at 525 MHz. This is a misdemeanor violation of 47 USC 301. I feel guilty so I am confessing to my blog readers. (Perhaps this confession will make FCC come after me!)

January 24, 2008 the 700 MHz auction starts. But a review today of the current text of 47 CFR 74.802 shows , guess what, wireless microphones are still there and have no stated eviction date!

Here's the current text:

§ 74.802 Frequency assignment.

(a) Frequencies within the following bands may be assigned for use by low power auxiliary stations:

26.100–26.480 MHz

54.000–72.000 MHz

76.000–88.000 MHz

161.625–161.775 MHz (except in Puerto Rico or the Virgin Islands)

174.000–216.000 MHz

450.000–451.000 MHz

455.000–456.000 MHz

470.000–488.000 MHz

488.000–494.000 MHz (except Hawaii)

494.000–608.000 MHz

614.000–806.000 MHz

944.000–952.000 MHz

(Emphasis added)

Then the current text of 47 CFR 74.803 deals with who they can't interfere with:

§ 74.803 Frequency selection to avoid interference.

(a) Where two or more low power auxiliary licensees need to operate in the same area, the licensees shall endeavor to select frequencies or schedule operation in such manner as to avoid mutual interference. If a mutually satisfactory arrangement cannot be reached, the Commission shall be notified and it will specify the frequency or frequencies to be employed by each licensee.

(b) The selection of frequencies in the bands allocated for TV broadcasting for use in any area shall be guided by the need to avoid interference to TV broadcast reception. In these bands, low power auxiliary station usage is secondary to TV broadcasting and land mobile stations operating in the UHF-TV spectrum and must not cause harmful interference. If such interference occurs, low power auxiliary station operation must immediately cease and may not be resumed until the interference problem has been resolved.

See any requirement not to interfere with 700 MHz CMRS licensees? So before you bid a few billion dollars, you might want to ask FCC to clarify what is going on here.

Microsoft Cognitive Radio Prototype Arrives at FCC

A 3/14/07 ex parte filing by the coalition of Dell, Google, HP, Intel, Microsoft and Philips confirms that the long awaited Microsoft-funded prototype cognitive radio has arrive at the FCC Laboratory for testing as part of Docket 04-186.

The coalition claims that this radio will function in the listen-before-talk mode and detect both TV stations and wireless microphones at low enough sensitivities in order to avoid occupied channels for TV band Wi-Fi-like use.

The FCC proposals in this proceeding have been extremely controversial, pitting new economy companies, such as the coalition members, against old economy companies like the TV broadcasters and manufacturers of UHF FM wireless microphones. At stake is providing low cost broadband access in rural America where TV frequencies are especially useful for long range communications in sparsely populated areas. The broadcasters claim the future of "free TV" is at stake.

The docket has accumulated 860 documents to date and no end is in sight.

I wrote the following article for the March 2007 issue of PolicyTracker, a London-based European spectrum newsletter and am using it here with their kind permission. So if the spelling seems a little unusual ... The wireless microphone issue is now getting a lot of attention at both FCC and the UK's Ofcom.

Wireless mics can enter the digital era

Complaints from the theatrical community in both the US and the UK are unjustified, says consultant Michael Marcus. He argues the problem is not an engineering one, but an issue of policy and economics.

A friend of mine in the US recently mentioned that he heard Sir Andrew Lloyd Weber on National Public Radio, the closest thing in the U.S. to BBC Radio 4, talking about the U.K.’s wireless microphone problem and the resulting threat to live theatre in London. I don’t know if any comparable U.S. figures have gone to London to give media coverage about their wireless microphone problem with FCC which allegedly threatens Superbowl coverage. How did this all start? In the days of analog TV, limitations of receiver technology made “whitespace”, i.e. vacant TV channels in a given area inevitable. Use of FM wireless microphones in this whitespace by broadcasters and theatres was a simple way to recycle this idle spectrum for something useful. Limiting eligibility to a small set of users meant they could mutually agree on its use. In this era, there was relatively little demand for spectrum anyway and no viable alternative for manual coordination. A lot has changed. DTV can use a higher fraction of available spectrum in a given region since receivers are more robust than analog receivers. This more intensive use of spectrum/ channels creates the “digital dividend” issue: one can either have more TV signals in the same amount of spectrum or pack the existing signals into a smaller TV band and ‘recycle” the remaining spectrum In the U.S. the TV stations of channels 2-69 will be packed into channels 2-51 in February 2009 as directed by Congress. There is also much more demand for wireless spectrum today than there was when the current wireless microphone use first developed. New cognitive radio technology now offers a more flexible alternative alternative to manual coordination of limited users for whitespace use. Thus a major policy challenge in both countries is how to address the needs for wireless microphones in today’s environment. In the U.K. Ofcom has proposed reserving one TV channel exclusively for wireless microphones. The broadcasters and theatres, ably represented by Sir Andrew, have stated that this will not be enough because they can only use today’s analog technology since digital technology will lead to audio delays that are unacceptable in live performance. ( See Digital Dividend Review: Ofcom fails to placate PMSE sector PolicyTracker 20.12.06) Now as a great admirer of Sir Andrew’s music, I am disappointed that he has taken to making poor engineering judgments. Does analog-to-digital conversion (DAC) always lead to large delays? No! No fee spectrum is part of the problem Linear predictive coding (LPC) is a DAC technology developed in the late 1970s for highly efficient compression of voice to binary data and is widely used in cell phones. Like other types of “source coding”, e.g. .zip and .jpg files, LPC involves a trade-off between delay and compression efficiency. But there are LPC parameter choices that trade-off delay for output data rate. There are also traditional DAC technologies without source coding where the delay is limited to the sampling interval, a small fraction of a millisecond. In wireless microphone applications distances are short so low data rates are not critical since the total amount of spectrum resource consumed in terms of bandwidth times area is small. 3G cellular technology can handle arbitrary digital streams including DAC from wireless microphones. Does the 3G industry offer a high quality wireless microphone today? No. There is no demand and hence no product development for spectrum efficient wireless microphones as long as low tech FM units have access to free spectrum use. Free spectrum is always cheaper than efficient wireless technology! Ofcom has proposed to dedicate one TV channel to wireless microphone use. In the U.S. FCC has proposed in Docket 04-186 to allow new unlicensed “TV band devices” to use TV whitespace alongside wireless microphones. The wireless microphone interests in the U.S. have strongly objected to the FCC proposals citing the technical complexity of protecting wireless microphones, which in theory are licensed, from the new unlicensed devices. They conveniently ignore the fact that most wireless microphone use in the U.S. appears to be by users who are not eligible for licenses under present FCC rules. Wireless microphones have real societal value as their proponents on both sides of the Atlantic argue. But the exclusive dedication of whitespace spectrum to them as in the U.S. status quo and the Ofcom proposal is clearly an inefficient use of spectrum since the spectrum use of this narrow application in time and space is quite limited. In view of the growing demand for all spectrum uses it makes more sense to accommodate the wireless microphone requirements in bands that are shared with other users and can give the wireless microphone systems the quality they need. The U.K. wireless microphone anti-digital claim is either a smoke screen to avoid increased costs for spectrum and equipment or arises from technical confusion. In any case, it is unlikely that there will be any development of more efficient alternatives for wireless microphones as long as regulators in the U.S. and U.K. allow indefinite use of today’s low tech models and don’t consider the opportunity cost of denying the whitespace spectrum to other users who could use it more effectively. •