Update: In 700 MHz Interoperability Push, FCC Acts Promptly on AT&T Prompt

FCC implements key provisions of AT&T’s 700 MHz interoperability proposal while extending interim construction deadline for 700 MHz A and B Block licensees until December 13, 2016.

In September we reported on a voluntary industry solution, proposed by AT&T and DISH Network, looking to bring interoperability to the 700 MHz block.  Since AT&T required, as a condition to its proposal, that the FCC adopt a number of rules to AT&T’s liking by December 31, 2013, we expressed some skepticism as to the FCC’s ability to meet that ambitious deadline. But lo and behold, the FCC has managed to do just that in record breaking time. 

In a "Report and Order and Order of Proposed Modification" released on October 29, the FCC, among other things, has modified: (a) certain technical requirements for the Lower 700 MHz D and E blocks; and (b) AT&T’s B and C Block licenses, as AT&T had requested as part of the voluntary industry interoperability solution.  The Commission also extended the interim construction benchmark deadline for all 700 MHz Lower A and B Block licensees until December 13, 2016, and issued a waiver of the interim construction benchmark for certain Lower 700 MHz A Block licensees that must limit their deployments in order to protect incumbent Channel 51 operations. 

What’s particularly noteworthy in the Order is the inclusion by the FCC of various escape valves AT&T provided for itself, which could delay the roll-out of 700 MHz interoperable devices for at least six months. It’s not clear what the FCC would do, if anything, to extend the interim construction deadlines for Lower A and B Block licensees should AT&T miss the deadline to begin the roll-out of interoperable devices.

In keeping with the breakneck speed with which the FCC seems to be dealing with AT&T’s proposal, the Order has been published in the Federal Register already. The amended rules are set to take effect on December 5, 2013, although the Order itself will technically be subject to judicial review until at least January 4, 2014 (and longer, if anyone seeks such review prior to that date).

Coming to a Network Near You - 700 MHz Interoperability . . . Maybe

Its sieve-like “commitment” to interoperability leaves AT&T multiple convenient ways to get off the hook.

For years, the build-out process for 700 MHz wireless networks has been slowed because of interoperability concerns. The FCC has made noises about possible regulatory resolutions, but so far those noises have not turned into agency action. So now a couple of the private players have announced their own solution. 

FCC Acting Chairwoman Clyburn has loudly proclaimed that that “solution will resolve the lack of interoperability in the lower 700 MHz band in the most efficient manner”. But heads up – as the Chairwoman correctly notes, this is a “voluntary industry solution”. Here, “voluntary” is used in its conventional meaning (as opposed to when the Enforcement Bureau refers euphemistically to the “voluntary contributions” it extracts from targets of its investigations). 

Let’s peek behind the curtain to see what we’re actually getting, shall we?

[Blogmeister’s Note: If you’re new to the whole interoperability problem, check out our post from March, 2012 for some useful background.]

Small carriers holding 700 MHz licenses have long complained that it isn’t viable for them to build out their licenses unless there is interoperability with nationwide carriers. Small carriers operate in Band Class 12. AT&T and Verizon Wireless’s 700 MHz networks operate in Band Classes 17 and 13, respectively. Due to the different technologies and wireless protocols used, none of the classes can talk to each other. So user devices manufactured for Band Class 17 can’t operate on the networks of the smaller entities, even though Band Class 12 and 17 devices both operate on the B and C Blocks.

The recently-announced interoperability solution looks to fix that, at least for Band Classes 12 and 17 (which operate in the Lower 700 MHz B and C Bands). In separate “commitment letters”, AT&T and DISH both have made certain commitments subject to certain conditions. AT&T’s letter is the more interesting of the two as it contains very positive developments for 700 MHz interoperability if fully realized. DISH offers to implement voluntary power reductions to make the whole deal work.

What exactly does AT&T have in mind? 

AT&T dangles the prospect of lower 700 MHz interoperability. In particular, it spreads on the table an attractive set of steps it’s willing to take:

  • AT&T will implement its new Multi-Frequency Band Indicator (MFBI) features throughout its network by September 30, 2015.  According to AT&T, the MFBI capabilities will permit AT&T’s network to operate simultaneously as Band Class 12 and 17 networks, and support devices in both bands. 
  • Once MBFI has been fully implemented, AT&T will begin providing LTE roaming Band Class 12 devices, and begin a two-year “Band Class 12 device roll-out period”.
  • During the first year of the Band Class 12 device roll-out period, AT&T commits to having 50% of its handsets that operate on the 700 MHz bands to be Band Class 12 capable.  During the second year of the device roll-out, AT&T will have 75% of its 700 MHz devices Band Class 12 capable.  After the two year device roll out period, AT&T states that all of its 700 MHz devices will be Band Class 12 capable.  AT&T excludes “M-two-M” (or M2M) devices from its commitment.

Interoperability heaven, right? Not so fast.

When AT&T acquired its lower 700 MHz D and E Block licenses, the FCC restricted AT&T to operating those licenses under the same power and antenna height restrictions that apply to lower 700 MHz A and B block licenses, and also precluded use of the licenses for uplink transmissions.  AT&T would like to operate all E block licenses to modify that. So as a condition to making good on its interoperability “commitments”, AT&T is insisting that the FCC adopt an order by December 31, 2013 requiring that all E block licensees transmitting a signal with an emission bandwidth greater than one megahertz are restricted to an ERP of 1,000 to 2,000 watts/MHz and an antenna height of 305 meters above average terrain.  

And if the Commission doesn’t adopt such an order by December 31, or if it does adopt such an order but the order is subject to appellate review, then AT&T “reserves the right to declare these commitments null and void”.

Sort of cheapens the concept of “commitment”. Not what you’d call totally “enforceable”. If AT&T were to back off some or all of its offers, the FCC’s only recourse would be to proceed with a rulemaking to implement its own 700 MHz interoperability rules. Bear in mind that the Commission has had an open proceeding looking into such rules since March, 2012. In other words, that approach doesn’t seem likely to produce any near-term results.

How big is the escape hatch that AT&T has provided itself? First, the notion of getting the FCC to adopt an order along the lines AT&T is looking for by December 31, 2013 is optimistic at best. The Commission is not known for prompt action, and let’s not forget that a new Chairman (along with a new Republican Commissioner) is likely to take over sometime between now and then. That kind of circumstance can slow things down at the agency.

And even if the Commission were to adopt AT&T’s desired order, AT&T is insisting that that order not be “subject to appellate review”. The order in question would be a rulemaking order. Before anybody could appeal it, the order would have to be published in the Federal Register, a process which often takes several weeks. And once the order is published, would-be appellants have 60 days in which to file their petitions for review. That considerably stretches AT&T’s ability to get out from its “commitments”. And if anybody were to file an appeal, the appellate process would ordinarily drag on for at least 12-18 months.

In addition, AT&T could delay the implementation of the Band Class 12 roll-out for six months if it were to determine that the MFBI implementation would result in “significant negative customer impact.”  AT&T further states that if it encounters “obstacles beyond its control” that threatens its ability to meet its commitments, or undermines the quality of its services, then it reserves the right to “seek an extension of time or a waiver” as appropriate.  In other words, the way AT&T has set up its “commitment” enables it to change its timeframes to suit its own schedule simply by sending the FCC another letter.

Notwithstanding the sieve-like nature of AT&T’s “commitment”, it still provides the industry with some basis for hope that the 700 MHz interoperability problem may be resolved sooner rather than later. We’re crossing our fingers that 700 MHz interoperability will come to pass without too much delay.

TV "White Space" Devices Go Nationwide

New action follows December roll-out to eastern states.

TV “white space” devices, which operate on an unlicensed basis in locally vacant TV spectrum, are now authorized nationwide. This is pretty fast, by Government standards; just last December the FCC okayed the first large-scale roll-out to seven eastern states plus Washington, D.C. The class of approved coordinators for the database these devices rely on to find open channels is growing much more slowly. Also growing slowly is the number of FCC-approved devices that can use the service; we count just five so far.

FCC Approves "White Space" Devices in Eastern U.S.

New systems must protect many other services from interference.

Fully four years after adopting rules for unlicensed TV Band Devices (TVBDs), also called “white space” systems, the FCC has authorized roll-out beyond the two small test areas previously approved. Touted by advocates as “Wi-Fi on steroids,” TVBDs can now boot up in New York, New Jersey, Pennsylvania, Delaware, Maryland, Washington DC, Virginia, and North Carolina.

The FCC expects to extend authorization nationwide by mid-January.

TVBDs are required to avoid causing interference to multiple services: broadcast TV; fixed broadcast auxiliary service links; receive sites for TV translators, low power TVs, Class A TVs, and multichannel video programming distributors; public safety and private land mobile; offshore radio telephone; radio astronomy; and “low power auxiliary service,” which includes licensed (and some unlicensed) wireless microphones. 

The complexity of the TVBD rules results from the need to ensure that all of these services can operate unharmed. In many metropolitan areas having multiple TV channels and heavy use of wireless microphones, vacant spectrum for TVBDs is already scarce. The FCC’s ongoing plans to consolidate TV broadcasters onto fewer channels, so as to free up more spectrum for wireless use, will only make things worse.

Simultaneously with the spread of TVBDs into the Middle Atlantic states, the FCC expanded its registration program for wireless microphones from those same states out to the rest of the country, keeping the wireless mic registrations a step ahead of the TVBD roll-out.

FCC Launches Nationwide Registration of Wireless Microphones

Registration is needed to protect qualifying events from interference caused by TV Band Devices

The FCC has expanded its registration program for wireless microphones from the Middle Atlantic states to the rest of the country.   Registration helps to protect qualifying wireless microphones that operate in vacant TV channels from interference caused by TV Band Devices (TVBDs), also called “white space” systems, that likewise use vacant TV slots.

When the FCC established rules for TVBDs, it required those devices to avoid interfering not only with TV stations, but also with several other categories of equipment operating on TV frequencies. The most populous of those, by far, are the wireless microphones that are ubiquitous in TV, stage, and film production.

Most wireless microphones used in TV and films are licensed by the FCC.  Most others – including those used in stage shows, churches, and the FCC meeting room – operated illegally until January 2010, when the FCC authorized low-power models on an unlicensed basis by waiver. (As it considers whether to make those rules permanent, the FCC recently sought to update the record on wireless microphone issues generally.)

Two TV channels in every market are closed to TVBDs, so as to leave room for wireless microphones. Licensed wireless microphones needing additional channels are entitled to interference protection from TVBDs. So are unlicensed microphones on other channels, but only if used for major sporting events, live theatrical productions and shows, and similar occasions that require more microphones than the set-aside channels can accommodate.

To implement protection, qualified events must register in the database that controls which frequencies TVBDs can use at each location. The FCC has authorized the operation of TVBDs in New York, New Jersey, Pennsylvania, Delaware, Maryland, Washington DC, Virginia, and North Carolina, and expects nationwide authorization by mid-January. Those who distribute or use wireless microphones should make sure any needed registrations are in place before TVBDs are deployed in their vicinity.

The details of the registration process are available here. The conditions and procedures are complex; and the FCC cautions that most uses of unlicensed wireless microphone do not qualify for registration. We recommend planning ahead.

Update: Revised "White Space" Rules To Take Effect June 18

Last month we reported on an FCC action that may mark the end of the decade-long “white space” proceeding authorizing the operation of some unlicensed devices in the broadcast television bands. The Commission’s Third Memorandum Opinion and Order (3rd MO&O), released in early April, disposed of a handful of petitions for reconsideration of the agency’s 2010 decision which had in turn tweaked technical “white space” specs adopted back in 2008. The 3rd MO&O has now been published in the Federal Register, which means that, barring any extraordinary intervening event (like the issuance of a stay – the approximate likelihood of which is pretty much zero), the rules as modified last month will take effect on June 18, 2012

FCC Adjusts "White Space" Rules

Minor changes may signal an end to almost a decade of rulemaking.

The FCC has released yet another decision in its long-running effort to implement rules allowing unlicensed “white space” devices in the television bands. The latest revision does not represent any wholesale changes, but will make it easier for some devices to operate.

White space devices (TV Band Devices or TVBDs, in the FCC’s nomenclature) rely on the fact that every location has some TV spectrum not being used. Those vacant frequencies typically show up as white spaces on a map of spectrum occupancy – hence the name. Technical studies show that properly controlled unlicensed devices can use these channels without causing interference to TV operation and other authorized users, including wireless microphones.

Following a Notice of Inquiry late in 2002, and a 2004 Notice of Proposed Rulemaking, the FCC first adopted rules allowing white space devices in 2006, but left the technical specifics for a later date. Those came in 2008, and then in 2010 the FCC responded to petitions for reconsideration with a number of revisions. Now the FCC has addressed petitions for reconsideration of the 2010 order.

The rules categorize each white space device as either fixed or mobile. A fixed device must have its location either professionally programmed in or determined by an on-board GPS device, and is subject to limits on operating power, antenna height, and antenna gain limits. Before operating, it must query a database of available spectrum for its location. A mobile device may similarly use GPS to determine its location and then query a database (Mode II devices); alternatively, it can contact another white space device that will in turn query the database (Mode I devices). The FCC has so far approved ten private companies to administer the databases, of which two have completed testing to the FCC’s satisfaction.

In its recent order disposing of the petitions for reconsiderations, the Commission provided the following changes and clarifications:

 Antenna Height. The 2010 rules limited fixed device antenna heights to a maximum of 30 meters above ground, and the height above the average terrain (HAAT) to no more than 76 meters. Several parties requested reconsideration of this restriction, particularly the HAAT portion. (According to one, the majority of the state of West Virginia would have been off-limits.) The FCC now allows fixed white space devices to have antennas up to 250 meters above average terrain, although still no more than 30 meters above ground level. At the same time, the FCC revised the separation distances between fixed white space devices and television contours to allow for the greater HAAT, but left unchanged the separations for wireless microphones and the exclusion zones around MVPD, LPTV, and BAS receive sites.  A device that provides database information to Mode I portable devices must comply with the previous HAAT limitations, so as to keep the Mode I device from straying too far from a known location.

Out-of-Band Emissions: The 2010 rules limited out-of-band emissions to 72.8 dB below the device’s highest in-band emissions. Now the out-of-band emissions are relaxed to 72.8 dB below the maximum power allowed within the 6 MHz bandwidth. The new order also cuts back the required occupied bandwidth from 6 MHz to 5.5 MHz, so as to ease the roll-off at the channel edges, and slightly increases the allowable power spectral density so as to leave total power unchanged.

Channel 52 Protection:  As part of the transition to digital television, the FCC auctioned former TV channels 52 and above for wireless use. The wireless companies have long sought restrictions on channel 51 TV operation to protect their frequencies just above, and similarly requested limits on white space devices on channel 51. The FCC refused, partly on procedural grounds, and partly on the principle that white space devices, being unlicensed, are already required to protect licensed wireless operations.

Classes of Devices: The FCC rejected a new class of white space device, similar to “Mode II” but for indoor use only, without GPS capabilities. The FCC feared these could be easily moved without updating their locations, thus creating interference. It also found the new class to be largely unnecessary, as Mode I portable devices may operate without geolocation (although they must query a Mode II or fixed device periodically).

Confidentiality of Database Information: The FCC makes publicly available all information required to be included in the databases that white spaces devices must search before operating.  A cable association asked the FCC to withhold certain data, including coordinates of cable headends and towers, claiming this type of equipment was “critical infrastructure” that could be subject to terrorist attack. The FCC disagreed with the premise and refused the rule change.

Finally, the FCC clarified two points. It emphasized that LPTV, television translator, and Class A television stations will have their receive sites protected based on the coordinates available in the existing CDBS database. The FCC will create a new web interface so that broadcasters can update the information. Second, the recent order corrects the coordinates of certain radio astronomy sites, which must be included in white spaces databases and protected by white spaces devices.

Most of the rule changes will take effect 30 days after publication in the Federal Register. Revisions to the filing of receive site information and entry of other information into the white spaces databases require OMB sign-off, and will probably take a few months longer.   Check back here for updates.

So far all of these rules control only a limited deployment in Wilmington, NC. But with the rules approaching final form, and more databases coming on line, white space devices may finally take the big step from PowerPoint to reality.

Update: Comment Deadlines Set in 700 MHz Interoperability Rulemaking

Less than two weeks ago the FCC released its Notice of Proposed Rulemaking (NPRM) exploring basic questions of interoperability of wireless services in the 700 MHz band. Acting with lightning speed, the Commission has hustled the NPRM has into the Federal Register. Publication in the Register sets the deadlines for comments and reply comments in response to the NPRM – and in this case the Commission has been generous to would-be commenters. Comments are due by June 1, 2012  and reply comments by July 16.

700 MHz Interoperability Issue Reaches Primetime

FCC tackles key questions about the future of the band.

In response to years of increasingly urgent agitation about the need for interoperability in the 700 MHz band, the FCC has issued a Notice of Proposed Rulemaking to look into the basic questions of whether there are any interference issues raised by interoperability and whether there is a need for regulatory intervention to ensure that users of all licenses in the band have roaming access to each other’s spectrum and can get affordable handsets.

The problem arises because AT&T and Verizon have significant holdings in the 700 MHz band. Verizon has many licenses in the Lower A and B Blocks and the entire Upper C Block, while AT&T has Lower B and C Block licenses and all or most of the Lower D and E Blocks.   The 3GPP (i.e., 3rd Generation Partnership Project) standards setting body has established Band Class 12 to cover operation over the entire lower 700 MHz band and Band Class 17 to cover operation in only lower B and C Blocks. This means that user devices manufactured for Band Class 17 will not be able to operate on the A Block where the licenses are held mostly by smaller entities, though the A Block licensees will be able to operate on the B and C Blocks.

You might think that it would be the Verizon and AT&T customers who would have the most to lose from this situation, since they would have Class 17 handsets and would not be able to roam in many of the smaller rural areas where A Block licensees will be building out.   To be sure, AT&T and Verizon customers will find that they are unable to get 700 MHz service in places where only A Block service is available. But the thing that gives A Block licensees nightmares is not so much the loss of that significant roaming revenue, but the inability to get handsets at all.

It seems that handset manufacturers know very well where their bread is buttered. If they can get orders in the millions from Verizon and AT&T, why should they bother designing, testing and producing a different handset for the limited market represented by A Block licensees? That market segment is simply not attractive enough to justify major investment from the big equipment vendors. Even a firm the size of C-Spire had difficulty getting A Block handsets at economically reasonable levels.  One question left unanswered by the FCC or the comments to date is “what about Verizon’s A Block licenses?”  Since Verizon is also a large A Block licensee, it will presumably have to place orders for units using Band Class 12, which would break the ice for other carriers to buy similar equipment from the same manufacturers. (This assumes, of course, that exclusive manufacturing arrangements have not been entered into by Verizon that preclude A Block sales to independent carriers – not always a safe assumption.)

The interference claims raised by Verizon and AT&T in support of the separate Band Class arise from the proximity of TV Channel 51 to the A Block.    Recall that the 700 MHz block was created out of the old UHF TV Channels 52 to 69 that were vacated by the Digital Transition in 2009. TV Channel 51 continues to sit adjacent to the A Block, and digital TV licensees can operate at up to a million watts in power. There is therefore theoretically the potential for adjacent channel interference from that high power source in many parts of the U.S. Since the B and C Blocks don’t need to worry about such interference, they can be designed without that issue in mind. AT&T says that if the interference concern can be resolved, it has no problem going with Band Class 12.

So this all leaves the FCC with a few basic questions. Is there really potential interference from Channel 51 that cannot be safely avoided by appropriate filters in 700 MHz handsets? Is the market really not functioning to permit independent licensees to buy Class 12 handsets at a reasonable cost?   Does the FCC even have the power to do anything about this since it has limited direct authority over equipment manufacturers?   This proceeding must be wrapped up quickly since Verizon and AT&T are already rolling out LTE service on their 700 MHz bands using Class 17. The more that such units get out into the marketplace, the harder it will be to impose a consistent policy across the whole user community.

The FCC candidly admits that it is hoping that the industry itself will work out a solution to this problem without regulatory intervention.   So far it has been loath to impose interoperability conditions on AT&T and Verizon in the context of their spectrum acquisitions, but the need for a global solution is becoming increasingly urgent for all parties as the initial build-out deadline for 700 MHz licensees approaches and the need for broadband spectrum becomes more intense.  Both of the new Commissioners whose confirmations have been languishing in the Senate for many months are well aware of the interoperability issue and seem to have expressed some sympathy for A Block position, so their entry onto the scene may also help to sweep the FCC to action.

The deadlines for comments and reply comments in response to the Notice of Proposed Rulemaking will be established when the Notice is published in the Federal Register. Check back here for updates.

Wireless vs. Broadcast: Chalk One Up for Wireless

FCC moves to protect broadband licensees from TV Ch. 51

Perhaps frustrated at the slow pace of Congressional cooperation in passing incentive auction legislation to allow it to take a meat cleaver to the TV spectrum and serve up a chunk to wireless operators, the FCC is starting to chip away at TV with a small ice pick. The first move is to put Channel 51, the uppermost TV channel, on ice, imposing an immediate freeze on applications for new stations and improvements in existing stations on that channel.

As we wrote back in March, Channel 51 is immediately adjacent to the 698-746 MHz band (formerly TV Channels 52-59), which have been reallocated to wireless services. Channel 52 has been auctioned, and the winning bidders don’t like the idea that the high power used by TV stations might blast their smaller wireless devices into oblivion. They asked the FCC to, in effect, create a guard band on the TV side of the border rather than the wireless side by stopping any growth on Channel 51.

The FCC has obliged, with a combination of steps that freeze and thaw at the same time, apparently intended both to stop growth on, and to encourage abandonment of, TV Channel 51.

Remember that while the FCC is considering how much of the TV band it can chop off for wireless use, it has already frozen growth in the entire TV band. No new applications or channel changes are allowed for full power stations, and no new applications are being accepted for low power TV stations on any channel. All of this is to ensure a fixed database when the FCC is ready to use the cleaver. 

But clearing Channel 51 has risen to a higher priority than having a fixed database, so the scramble is on.

Full power TV stations on Channel 51 are invited to get out of Dodge right now and move to any lower channel they can find. Their rulemaking petitions to amend the TV Table of Allotments and their applications for construction permits to change channel will get the warm fuzzy treatment. On the other hand, pending applications for new LPTV stations on Channel 51, most of which were filed in 2009 and 2010 and were being processed up to now, have been given the liquid nitrogen treatment and flash frozen – except that before the freezer door is shut and locked, they too can enjoy a thaw in the form of a 60-day window to change channels. Channel-change amendments are normally major changes that were previously forbidden, but they will now be classified as permissible minor changes for those who can find a lower channel.

Existing full and low power stations authorized on Channel 51 may continue to operate undisturbed -- undisturbed, that is, except for the long, dark  shadow now cast on their long-term future. They will be permitted to file minor change applications, but only if they do not propose to cover any new area they did not cover before. That will place a considerable damper on LPTV stations that are used to hopping round and inching toward larger markets.

The new dance floor is for only Channel 51 stations and applicants. Anyone on any other channel remains subject to all the old processing rules: full power stations may not change channels, LPTV applications will be processed but no new applications will be accepted, and any station may file for a minor change even with an expanded service area.

There are some things we still don’t know. One is whether any priority will be given to Channel 51 abandoners. Obviously full power stations may move to new channels and exterminate secondary LPTV stations in their way, both incumbents and applicants. But what about existing LPTV stations that do not have to abandon Channel 51 but want to skeedaddle while the skeedaddling is good? Will they be allowed to claim that they are displacement and move now? If so, will their applications take priority over ungranted earlier-filed applications for new LPTV stations or changes in existing stations, the way that displacements from Channels 52-69 do? Will Class A stations be treated any differently from LPTV stations? Will amendments to pending Channel 51 LPTV applications take priority over pending applications on lower channels? And what about granted but unbuilt construction permits for new LPTV stations on Channel 51? May they build on 51? If they prefer to move, may they do so as a minor change the way pending applicants may do?

And you thought that the TV database was going to be held in place pending further notice. It looks more like the hopscotch game has begun.

Update: FCC Seeks Comment On Channel 51 Licensing Limits

A week ago, we posted about a “range war” in the spectrum around TV channel 51. The wireless providers who bought spectrum just above channel 51 at auction must configure their operations to protect channel 51 TV reception. They have since asked the FCC to limit channel 51 licensing so as to minimize their own burden. See the original post for details.

The FCC has now requested comment on the wireless companies’ request.   Comments are due on April 27, 2011, and reply comments on May 12, 2011. Note also that the FCC has made this a “permit-but-disclose” proceeding, which means that face-to-face meetings between interested parties and the Commission’s staff are OK, as long as the niceties imposed by the FCC’s ex parte rules are honored.

Range War 2011: Broadcasters vs. Wireless Providers

Wireless companies in spectrum adjacent to TV channel 51 want their neighbors to vamoose.

In the Old West, even the vast wide open spaces were not vast enough and wide enough for everybody. Farmers and cattle ranchers fought over scarce resources, like water and grazing rights.   These conflicts were known as range wars.

The tradition lives on, but the turf in dispute today is spectrum, particularly TV channel 51. The wireless companies want to ease out the TV broadcasters, who may want to stay put. Better hunker down; the legal papers are going to fly.

The dispute is a by-product of the digital TV transition a few years ago. Digital technology allowed the geographic repacking of TV stations into fewer channels than before. That freed up 108 MHz of spectrum in the 700 MHz band, part of which the FCC auctioned off to wireless broadband providers for almost $20 billion. Even here in Washington, that counts as real money. The government got the cash; the broadcasters got to quadruple their video capacity; and the wireless companies got more bandwidth, over which customers could download more videos of cats riding on vacuum cleaners.

Now the happy honeymoon is over. Reality has settled in. The domestic-bickering phase has begun.

The immediate issue is TV channel 51, which (after the transition) is the highest TV channel at the highest frequency. Just above it in the spectrum, where channel 52 used to be, is the lower portion of the wireless 700 MHz band, known to the cognoscenti as A Block. But channel 51 and A Block are on different frequencies, right? So there should be no conflict.

That sounds logical, but it’s wrong.

The problem lies in receiver design. Channel 51 covers 692-698 MHz. Ideally a TV set tuned to channel 51 would receive everything in that range, and nothing above or below. Sadly, though, that is not possible.  You can build a receiver that comes pretty close, but it would add more cost to the TV than a consumer wants to pay. A real-world TV receives some signal above and below the channel it is tuned to. In particular, a TV tuned to channel 51 will pick up some signal from above channel 51, in wireless A Block. The TV does not show the cat on the vacuum cleaner, but the wireless signal can degrade or even block the TV reception. The reverse is likewise true: reception on an A Block mobile wireless mobile device can be impaired by a nearby TV station on channel 51.

Of course, that last irks the wireless companies. Even worse, from their standpoint, is their legal obligation to protect channel 51 TV reception. The strength of the wireless signal must not exceed that of the TV signal by more than a certain amount within the station’s service contour, which for this purpose is anything within 55 miles of the station.

Two factors make compliance difficult. First, some Block A devices are mobile handsets that can inadvertently stray into the 55-mile zone and put out more power than is allowed. This is hard to prevent. Second, although the viewing public thinks of TV stations as being relatively permanent, in fact they come and go and change their channels (all subject to FCC consent). So even if an A block wireless company can work around all the stations currently operating on channel 51, another one can pop up at any time.

The wireless company trade associations have filed a petition with the FCC to complain about these problems and request relief. The petition opens with several pages on the importance of wireless broadband (no mention of the cats). Then come three requests:

  1. change the rules to foreclose all future TV licensing on channel 51;
  2. in the meantime, freeze all future and pending TV applications to operate in channel 51; and
  3. streamline procedures for facilitating “voluntary efforts” to relocate existing channel 51 licensees to other channels.

To be sure, the problems facing A Block licensees should not be a surprise. The companies that bid on that spectrum knew they would have to protect channel 51 TV stations, including later arrivals, and they knew the risk of incoming interference from TV operations. They bought the spectrum anyway, “as is.” Yet now they want the FCC to control the number of channel 51s they must deal with. They also hint that people might seek channel 51 licenses “to exploit opportunities for personal gain” at the expense of an A Block licensee – in other words, to deliberately make trouble for a wireless company, with an offer to go away if paid enough money. On the other hand, the “voluntary efforts” mentioned in item 3 above appear to involve payoffs to existing channel 51 licensees from willing wireless A Block licensees.

The wireless companies could have solved their problem, in principle, by leaving the lower part of A Block vacant as a guard band. That would cost a lot of money. Instead, despite not having paid for it, they want the 6 MHz of channel 51 to be vacant.

The FCC has not yet put out the request for comment. We will let you know if and when that happens.