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Incentive Auction FAQ

I've read a number of posts and comments on message boards and mailing lists over the past several months, and I continue to read a lot of misinformation about what the incentive auction is and how it works. In the interest of educating those who don't know the facts of how this process will work, I've written an FAQ which attempts to be as unbiased as possible, which you can read by clicking the link below.

Opinions contained in the following FAQ represent my personal opinions and readings of the various documents, and are not necessarily reflective of the opinions of my employer. Also, even if the very long question about OET Bulletin 69 does not interest you, please note there is a final FAQ question below it at the bottom.

Where did the TV Incentive Auction come from?
The TV Incentive Auction was proposed in 2010 in the FCC's National Broadband Plan and legislation mandating such an auction was passed by Congress and signed by the President as a part of the Middle Class Tax Relief and Job Creation Act of 2012. The FCC issued a Notice of Proposed Rulemaking in Fall of 2012 about how to implement the auction, which was adopted in the May 15, 2014 Report and Order. Here is a high level summary of the Report and Order.

What is the TV Incentive Auction?
The TV Incentive Auction is designed to be a market-based approach to spectrum reassignment. UHF and high-VHF TV stations can volunteer to participate in a process known as the “reverse auction” by agreeing to channel share, move to high-VHF or low-VHF, or go off the air, for a price. Wireless companies bid on the resulting freed spectrum in a more traditional "forward auction." From the proceeds, the FCC will pay to relocate the remaining stations to other channels (called "repacking," not "repackaging" as I keep reading) and thus clear contiguous spectrum from channel 51 down. Additional proceeds go to paying the FCC's costs, paying for a first responder network ("FirstNet") and paying down the national debt.

Can stations be forced to channel share, move to VHF, or go off the air?
No, they cannot. Stations cannot be required to do any of those things. The auction is strictly voluntary. Stations cannot be required to channel share, and they cannot be required to go off the air. They cannot be required to move from UHF to VHF, nor from high-VHF to low-VHF.

Which stations are protected?
All full-service and Class A stations are protected and subject to being compensated for repacking costs. LPTV and translator stations are not.

Will stations below the channels that are cleared be moved as well?
Almost certainly. Any full-service or Class A station is eligible to participate in the auction. TV stations that remain on the air after the reverse auction on channels below the cleared band could be repacked to allow all of the non-participating stations outside the shrunken UHF TV band to find homes. Sophisticated software, powered in part by the TVStudy software I work on at my day job, will optimize the channels assigned to every remaining station while preserving the current interference-free service areas of those stations.

As a simplified example, WPXN in New York, WPPX in Wilmington/Philadelphia, and WTIC in Hartford are all on channel 31. WNBC, currently on channel 28, does not have co-channel interference from stations in Philadelphia or Hartford. As such, if WPXN were to be sold in the reverse auction, while WPPX and WTIC were to not sell, WNBC could not be placed onto channel 31 because its current interference-free service area would be reduced by such interfering stations. The Repack Check tool I wrote last year uses example FCC data to show these relationships, and given changes that were adopted in the Report and Order, an update to the FCC data is anticipated.

What happens if not enough stations participate in the entire country?
There is a minimum amount of money the auction must make in order to "close," and thus complete. It must pay for the costs of repacking incurred by non-participating broadcasters, pay the cost of the spectrum purchased from participants in the reverse auction, pay the FCC's costs, and fulfill the remaining part $7 billion requirement to fund FirstNet. (The H-block auction earlier this year raised about $1.56 billion toward the FirstNet requirement.) There is also a minimum spectrum requirement, to be determined, as it would make no sense to expend billions of dollars to free up only 12 MHz of spectrum. Essentially, if nobody volunteers, nothing happens.

What happens if not enough stations participate in a particular area, such as near the borders?
The goal is to have a single 600 MHz wireless band nationwide based on what the majority of the population could use, but it could be slightly smaller in a few select places where the full 600 MHz band cannot exist due to the number of TV stations. If a large percentage of the country's population has channels 14-36 for UHF TV, as an example, that would be the nationwide plan, with some additional TV channels above 36 where necessary to accommodate those few markets where that amount is not reached. What will not happen is the reclamation of additional spectrum in rural areas beyond that which is available to a majority of the nation's population. For example, Glendive, MT has no UHF full-service or Class A stations, but if the UHF TV band were to be channels 14-36 in most of the country, that would also be the UHF TV band in Glendive.

The Report and Order postponed a decision on how to avoid interference between wireless and TV stations in these areas. Earlier this year, the FCC proposed standards for evaluating inter-service interference (ISIX), which could come into effect in the event that a certain portion of the country has less available spectrum than the rest of the country.

What changes does TVStudy make to the "methodology described in OET Bulletin 69"?
Disclaimer: I work on TVStudy as my day job. Please read my response through that lens, and feel free to use as many grains of salt as you wish.

None. OET-69 is a paper bulletin which describes how a piece of software can be written to evaluate TV station coverage and interference. However, it does not describe all of the parameters that are required for such an implementation, and in a public notice sought comment on adjusting some of the unspecified parameters from how they were implemented in previous software implementations. The National Association of Broadcasters (NAB) has repeatedly argued in its various comments and public statements that OET-69 is also a piece of software, in addition to a paper bulletin; however, the FCC has at least three different implementations: FLR, tv_process, and dlptv_study. Each has different settings and parameter choices made, and thus each can give a different set of results. In addition, there are even certain areas where the settings vary from the parameters strictly laid out in the paper bulletin in all three implementations.

So just what adjustments to the non-specified parameters are being made? Here is a brief description of the adjustments stated in the Report and Order, along with one that was proposed but not adopted.

  1. The old implementations all used 3-second terrain, compiled from seemingly different sources, which the USGS no longer provides nor supports. These data sets had known errors, including an inability to handle negative elevations such as in the Imperial Valley of California, and one implementation which had no terrain data at all for Alaska. TVStudy will use 1-second terrain, which is fully supported and updated by USGS.
  2. The old implementations used 1990 or 2000 Census data for population analysis. TVStudy will use 2010 Census data, the most current available.
  3. The old implementations did not attempt to correct obvious errors in the FCC database. In addition to recent efforts to clean up the database, which I was personally involved in, TVStudy has the ability to fix obvious errors that slip through the cracks, such as fixing negative beam tilts which would aim most of the power toward the sky instead of toward viewers on the ground.
  4. The old implementations assumed all stations had an electrical beam tilt of 0.75°. TVStudy will use the actual value found in CDBS, which is presumed to have been selected to maximize service.
  5. The old implementations did not properly calculate the angle from the transmitting antenna to the receive point on the ground. TVStudy fixes this error.
  6. The old implementations rounded the coordinates of Census data points to the nearest second, presumably due to memory limitations of the computer used when the old implementations were first written in the late 1990s. TVStudy will not round these values.
  7. The old implementations established signal evaluation points based on an independent "local grid" unique to each station. TVStudy will use the same set of evaluation points in a "global grid" for all stations, thus allowing apples-to-apples comparisons of coverage and interference, and allowing such calculations to be cached and recycled in order to significantly improve performance.
  8. The old implementations replicated stations to different channels by creating a directional antenna which matched the old contour at a specific power level. This often made omni stations directional and produced antennas that were impossible to build. TVStudy will instead hold the antenna pattern constant while increasing or decreasing power to match the area inside the old contour.
  9. The one proposal which was not accepted in the Report and Order was to change the treatment of Longley-Rice warnings. The Longley-Rice model is based, in part, on a multitude of actual real-world measurements, but as one might expect, not all possible signal paths were tested, such as those where the first terrain obstruction occurred at an angle of greater than 200 milliradians (11.46°). In those cases, the model extrapolates based on the data it does have to calculate a result, but it also throws "kwx=3" warning which means the result may be "dubious or unreliable." Comparing these calculated values against later measurements has shown that the two seem to generally agree, but the FCC has historically thrown away the calculated value and assumed service in the cell, even if an interfering signal does not throw "kwx=3" and would otherwise cause interference. Though the public notice proposed to accept the result, the FCC declined to change this behavior and decided to continue assuming service and completely ignoring any interference in these cells.

The FCC has an obligation to use the best and most up-to-date available inputs and software, and these adjustments are how the FCC will meet that obligation while staying within the confines of OET Bulletin 69.

The following is strictly my personal opinion, and not necessarily reflective of the opinions of the FCC. If not for the confines of OET Bulletin 69, there are a number of changes I would have personally liked to have made to more accurately reflect station coverage, such as:

  1. To avoid some "kwx=3" warnings, after determining the evaluation point for a given grid cell, if it contains population, moving the evaluation point to the nearest point which has population. This would prevent an evaluation point from being placed at the bottom of a lake or river, for example.
  2. An urban noise adjustment for VHF, to reflect the reduced signal strengths that VHF stations experience in those areas.
  3. Decreasing the cell grid size from 2 km on a side to 1 km on a side.
  4. Using mechanical beam tilt for stations which have accurate horizontal and vertical patterns in the database, and encouraging stations with mechanical beam tilt to file those patterns to have as many of them on-file as possible.
  5. Using actual elevation patterns for any stations which have them, and encouraging stations to file those patterns to have as many of them on-file as possible.
  6. Mirroring the generic vertical pattern to reflect that antennas do not radiate at full power toward the sky.
  7. Decreasing the receive antenna height from 10 meters to 9 meters for a better match of the assumption of a "30 foot high" receive antenna.
  8. Increasing the number of terrain points used for Longley-Rice calculations from 1 point per kilometer to 10 points per kilometer.
  9. Increasing the number of terrain radials used to calculate contours from 8 to 36, 72, or 360. (The RabbitEars contour maps use 360 radials, and the old implementations actually use 72 despite OET Bulletin 69 specifically saying 8.)
  10. Changing the method of calculating contours from the present "F Curves" method to a Longley-Rice based method that incorporates actual terrain roughness and path loss calculations.

Have a question I didn't answer?
Post it in the comment. If it's general enough to belong in the FAQ, I'll add it in. If not, I'll try to answer it in the comments.


1. On Tuesday, June 3 2014, 13:28 by RingtailedFox

how will this affect Mexican and Canadian stations in border areas, like San Diego/Tijuana and Detroit/Windsor?

Will Mexico and Canada be pursuing their 600 MHz wireless band strategies as well, or is this a USA-only deal?

2. On Tuesday, June 3 2014, 16:23 by Trip Ericson

The report and order says basically that "international negotiations are on-going." Which isn't helpful, but basically means there is not yet an answer to your question.

3. On Tuesday, June 3 2014, 22:33 by itsthemultipath!

As I understand it, the uplink band (handset to tower?) will be from channel 51 down (698 Mhz and lower) while downlink (tower to handset?) from 36 down (602 MHz and lower).

If the auction were to max out, assuming the uplink and downlink spectrum are equally paired, does this mean that the downlink will be channels 23 (!) to 36?, with channel 22 likely being off limits to protect mobile from ACI like channel 51, and channels 14-20 shared with mobile, leaving a SINGLE CHANNEL (21) exclusively for UHF DTV?

Would not the downlink transmitters cause a front-end overload problem for DTV receivers (and especially antenna preamplifiers), as some are already experiencing from 700 MHz 4G LTE sites?

Finally, if the auction is partially "successful", would that mean that many areas would have no DTV on RF channels 32-36, nor on 47-51, but could have DTV on channel 45?

4. On Wednesday, June 4 2014, 08:12 by Trip Ericson

For purposes of making the auction software not crash, they had to have band plans for up to 30 channels, which would mean only channels 14-20 would be left in UHF, I believe. Nobody in the FCC or anywhere else actually anticipates that outcome.

You're correct that uplink is handset to tower, and downlink is tower to handset. It's not necessarily 36 down, it's the lower half of whatever the auction produces. So if 84 MHz (channels 38-51) is sold, then the uplink is 46-51 while downlink would be about 38-44, theoretically, with 45 being a duplex gap with no TV stations.

Most of the issues the FCC has seen, to my knowledge, are adjacent channel interference problems, either from 52 to 51 or 51 to 52. So having the 6+ MHz guard band at the bottom end is designed to mitigate that. It also makes a low-pass filter easier to build to solve any potential issues, as opposed to 51 and the A block on 52 having about 1 MHz of space (since LTE tends to operate 699-704 MHz).

I think I answered your final question earlier in this comment.

5. On Friday, June 6 2014, 16:15 by Isaac Valenzuela

Great post Trip, very informative even for a laymen like myself. In your opinion do you think the auction will be successful?

6. On Saturday, June 7 2014, 18:18 by Trip Ericson

I don't know that my superiors would like me sharing an opinion on that.

7. On Monday, June 9 2014, 00:03 by Mark

What impacts (if any) will this have on "T-Band" users (i.e. LAPD - Channel 20, LA Sheriff - Channel 15/16 and agencies on Channel 14?

8. On Tuesday, June 10 2014, 07:29 by Trip Ericson

None, at this point. They are considered in the "domain" file for the purpose of the auction, as channels unavailable for use by TV.

9. On Wednesday, July 2 2014, 13:06 by w9wi

Isaac, I'm thinking there's more than one definition of "successful" in this auction.

I suppose you could argue it will be "successful" if *any* spectrum in a large market can be repurposed for wireless. And even if *no* TV station agrees to sell their spectrum, I would imagine some repacking will be possible, some spectrum will become available.

We're pretty sure a few stations *will* sell their spectrum.

So I think we can assume it will be successful at at least a minimal level. Will it clear as much as the policymakers hope? I doubt it.

10. On Thursday, July 10 2014, 12:00 by Trip Ericson

If no TV stations were to participate, at most, 12 MHz could be recovered, not even enough for the guard band and a single 5 MHz block.

11. On Thursday, July 10 2014, 13:42 by w9wi

- With nobody participating in the auction (again, not a likely scenario) wouldn't the amount of recoverable spectrum solely through repacking vary by market? I can see difficulty recovering anything useful in the Boston/NYC/Washington corridor. Might repacking make more available in, say, Dallas, or Chicago, or Seattle, where the surrounding areas are not quite as congested?

- Can the allocation plan be changed to provide smaller blocks if not enough is recovered to provide a single 5MHz block?

(again, I don't think that latter scenario would prove necessary)

12. On Thursday, July 10 2014, 14:01 by Trip Ericson

It would vary, but if you're losing half the population of the US (think NY, Boston, Philly, DC, Los Angeles, and San Francisco) it's not worth it to the wireless companies, so the auction would never close. I'm also not convinced that you could repack Chicago if nobody participated.

The wireless companies won't bid on blocks smaller than 5 MHz, and would prefer to have contiguous 10 or 20 MHz pieces since LTE will go up to 20 MHz in width.