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Will 600MHz affect the future of 4K over-the-air broadcast?


red_dog007
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So, with the 600MHz auction looming, broadcast television is about to lose a big chunk of useable wireless airwaves. 

 

VHF-Lo is 30MHz (5 Channels)

VHF-Hi is 42MHz (7 Channels)

UHF has 228MHz, but with 600MHz auction looming broadcast, seems like about half of that is going to be reallocated for cellular.

 

I'm just wondering what kind of implication this will or might have on the future of 4K over-the-air broadcast television. 

 

I imagine that rural markets, there wouldn't be anything to worry about.  But in markets that have limited or no white space remaining in the broadcast spectrum range, things might be complicated.  And it would be these areas that would be the primary pushers for 4K. 

 

Im trying to find information on ATSC 3.0, and 4K OTA, but I'm not really finding much.  I'd imagine that the big providers (ABC, FOX, NBC, CBS, and maybe PBS) would make the shift. But I'd imagine that they would either need to occupy an additional spectrum channel, or have to remove some subchannel networks completely.

 

Do you think 2016 will be the year of 4K OTA broadcast or might we have to wait a little longer?

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In my market (Cleveland/Youngstown, OH), there's already interference in excess of FCC guidelines for at least two stations in my region, so the only option really left is either sharing of channels, which means less bandwidth, or find out how to make VHF, especially LOW VHF, work well for digital television. This is why I'm critical of this "incentive auction".

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In my market (Cleveland/Youngstown, OH), there's already interference in excess of FCC guidelines for at least two stations in my region, so the only option really left is either sharing of channels, which means less bandwidth, or find out how to make VHF, especially LOW VHF, work well for digital television. This is why I'm critical of this "incentive auction".

I'm interested in this also.  Sometimes we have problems getting certain channels (the channel varies).  I wonder if it's from this "interference".

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No, not band 12.  He likely means co channel interference from outside the TV market or adjacent channel interference from within the TV market.

 

AJ

 

If that happened, shouldn't FCC take action on the person who cause the interference?

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If that happened, shouldn't FCC take action on the person who cause the interference?

 

The FCC is not a detective squad nor a police force.  The broadcasters would have to report the interference to the FCC.  Maybe two broadcasters have reached an agreement to accept interference from each other.  Or maybe the interference comes across the lake from Canada where the FCC has no jurisdiction.

 

AJ

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Interference? How? From B12?

In this case it is interference between television broadcast stations. It is allowable if the interfering stations both agree to the additional interference caused to each other. The two stations I'm referring to are WYTV (with a station in Maryland) and WNEO (with a station in Indiana, I believe).

 

I'm interested in this also. Sometimes we have problems getting certain channels (the channel varies). I wonder if it's from this "interference".

Often times propagation enhancement over the lake (tropo) reaps havoc with digital broadcasts on the same channel (as well as results in some mighty fine DX when interference isn't a factor), and an analog versus a digital signal is even worse. WOIO has been plagued with this problem with CFPL for years on RF-10. The can't return to RF-19 because of adjacent channel interference with WFMJ on RF-20. Edited by Joski1624
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...

Do you think 2016 will be the year of 4K OTA broadcast or might we have to wait a little longer?

Last I heard, it was still in development. Experimental testing was done last year in the Cleveland area for ATSC 3.0 and it was found that the UHD transmissions needed more work, so I don't see 4K broadcast television happening in the near future.

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As the resident TV guy, let me address the interference piece of this.

 

TV interference is very tricky.  I say that in the sense that the rules are as clear as mud and full of oddities.  My work for the FCC is on software that does exactly those calculations. 

 

http://data.fcc.gov/download/incentive-auctions/OET-69/

 

This post may contain opinions.  Those opinions are my own and do not reflect those of the FCC or its commissioners.

 

Let me provide a link and then I'll explain how it all works in the link.  I've used WYTV here, since it was brought up.

 

http://www.rabbitears.info/contour.php?appid=1364510&map=Y

 

TV station coverage is based on the F(50,90) service contour.  That's the blue outline you see on the map.  This contour is "projected" through a terribly complicated and at the same time ridiculously out of date method that was developed in the 50s or 60s.  The short explanation is that you use the terrain between 2 and 10 miles away from the transmitter in a given direction, find the average elevation, compare against the transmitting antenna elevation, and then use a lookup table of that height differential along with the power (adjusted for the antenna pattern) and channel number to get a distance.  (It's actually not that simple, but the full explanation would take several paragraphs and probably a few diagrams.  That will get you pretty close, though.)  Plot for that direction, then move to the next azimuth angle.  Repeat until you've done this for the entire 360 degrees.

 

If you are outside this contour, sorry, you don't count.  (Growing up, I didn't count.  That's why I hate contours.)  If you receive interference, that's too bad.

 

If you are inside the contour, now we start getting more sensible.  You break up the area inside the contour into rectangular grid cells.  A point is chosen as the representative point of each cell by using a weighted average of the census population points within each cell.  (If there's no population, use the center.)  Then you use the Longley-Rice path-loss propagation model to calculate the field strength at that point from the TV station in question.  If you're predicted to be below the service threshold (for UHF, it's 41 dBuV/m + a factor that varies with frequency) then you are deemed to have no service, and if there's interference at that point, it doesn't count.

 

But even that's not the whole story.  The model isn't perfect; in some cases, it will determine that its own calculation is "dubious" and spit out an error code (kwx=3) along with its calculation.  While studies have shown that calculation is generally correct, the FCC's policy from the time it started doing this in the 1990s through today is to assume the cell has service and ignore any potential interference stations.  By the FCC's calculation, that cell is now immune to interference.  So, again, if there's interference in the cell, it doesn't count.

 

So now we've gotten to just the cells that are predicted to have reliable service predictions.  You now do the same process in that cell with respect to each potential interfering station within 300 km of that cell.  Now, that kwx=3 error may appear again; if a potential interfering station triggers that error, it's assumed to not cause interference.  So, again, if there's interference in the cell (from that particular interferer), it doesn't count.

 

Finally, having done all of that, the field strength of the station you're analyzing is compared against the field strengths of the interfering stations.  As long as the station is at least 15 dB (depending) above the interfering stations, it is assumed to be interference-free service.  And that 15 dB varies with a formula that makes the threshold higher as the signal gets weaker.  Oh, and only cells with population are actually counted; interference only counts if it impacts people as defined by the census.  And interference from LPTV stations doesn't count either. 

 

All of that technical jargon aside, now you can actually look at interference levels that TV stations have.  According to the FCC's predictions, WNEO receives 3.52% interference, while WYTV receives 6.2% interference.  For good measure, WFMJ receives 2.4% interference, while WKBN receives 23.63% interference.  As for the specifics of the two that were mentioned:

 

WYTV:

4.8% unique interference from WTTE in Columbus, OH.

0.2% unique interference from WGPT in Oakland, MD.

0.0% unique interference from WLNS Lansing, MI, CITS-DT Hamilton, ON, and WOUC Cambridge, OH.

The remainder is caused by more than one of the above.

 

WNEO:

2.9% unique interference from WDIV in Detroit, MI.

0.3% unique interference from WWAT-CD in Charleroi, PA.

0.0% unique interference from WXCB-CD in Delaware, OH.

The remainder is caused by more than one of the above.

 

Now you might ask, how did all of that interference come to be?  In general, it's because stations agreed to accept that interference.  In some cases it was because of how the FCC assigned the channels during the DTV transition, which was a best effort to give every TV station a second channel, but usually it's because it was accepted by the station in question.

 

As to the original question in the first post... if desired I'll address that later.  That was tiring to type up.

 

- Trip

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Last I heard, it was still in development. Experimental testing was done last year in the Cleveland area for ATSC 3.0 and it was found that the UHD transmissions needed more work, so I don't see 4K broadcast television happening in the near future.

4K was broadcasted for CES this year. ATSC article says LG was show casing 4K with HDR off Channel 18 (KHMP). So at least a 4K over-the-air live demonstration at a major technology convention. :-)

 

Though looks like they did it last year too in 2015. :-/

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Thanks for the information, Trip. I thought that you might chime in. ;) It looks like the theoretical interference between broadcasters is more widespread than I thought. :o

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Im trying to find information on ATSC 3.0, and 4K OTA, but I'm not really finding much.  I'd imagine that the big providers (ABC, FOX, NBC, CBS, and maybe PBS) would make the shift. But I'd imagine that they would either need to occupy an additional spectrum channel, or have to remove some subchannel networks completely.

 

Do you think 2016 will be the year of 4K OTA broadcast or might we have to wait a little longer?

 

Not in 2016.  Not in 2017.  Look to a 2018-2020 timeframe -- at the earliest.  ATSC 3.0 will require a new set top box/tuner distribution program.  We already went through that process with the DTV transition just a few years ago.  It will be a few more years before we hit the reset button and do it again.

 

And I realize that with another ATSC standard, it might as well future proof with 4K.  But 4K OTA, honestly, is superfluous.  Get all 1080i/60 up to 1080p/60.  That is a more sensible goal.  Interlaced scan no longer has any place in 2016 and beyond.

 

AJ

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Maybe two broadcasters have reached an agreement to accept interference from each other.

Isn't this an extremely rare case? I know as far as FM, full service stations have to respect other full service stations' 1st, 2nd, and 3rd adjencent channels (all according to class/distance). Only cases I know of in which stations can overstep on co-channels are grandfathered cases (KGSR-FM and KLBJ-FM in Austin and KLVJ-FM and KGB-FM in San Diego come to mind)

maybe the interference comes across the lake from Canada where the FCC has no jurisdiction.

 

AJ

I always assumed that the FCC had TV spacing, power, and interference agreements with Canada's CRTC and Mexico's IFETEL (formely COFETEL, but just as corrupt) just like they do with Radio. Is that not the case?
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Isn't this an extremely rare case? I know as far as FM, full service stations have to respect other full service stations' 1st, 2nd, and 3rd adjencent channels (all according to class/distance). Only cases I know of in which stations can overstep on co-channels are grandfathered cases (KGSR-FM and KLBJ-FM in Austin and KLVJ-FM and KGB-FM in San Diego come to mind)

 

No, not if they come to contractual agreements to accept certain levels of interference.  T-Mobile has expedited its band 12 deployment by paying off broadcasters.

 

AJ

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Isn't this an extremely rare case? I know as far as FM, full service stations have to respect other full service stations' 1st, 2nd, and 3rd adjencent channels (all according to class/distance). Only cases I know of in which stations can overstep on co-channels are grandfathered cases (KGSR-FM and KLBJ-FM in Austin and KLVJ-FM and KGB-FM in San Diego come to mind)

I always assumed that the FCC had TV spacing, power, and interference agreements with Canada's CRTC and Mexico's IFETEL (formely COFETEL, but just as corrupt) just like they do with Radio. Is that not the case?

 

The FM rules are very different from the TV rules.  The DTV transition did away with the TV distance separations that still rule FM and replaced it with the OET-69 method I described above.  It also allows stations to negotiate to accept interference either for a price or for mutual benefit.  Or if a station is applying for a new facility, as long as it doesn't cause more than 0.5% interference, if it receives interference, it is assumed to accept that interference by default.

 

(And for the record, even FM isn't strictly distance-based.  Aside from grandfathered pre-1964 stations, it is also possible to use contour protection to short-space stations closer than the minimum distances so long as there is a location where the allotment would be fully-spaced.)

 

As far as international spacing, the protections are different at the borders due to those agreements, and the propagation model on either side does not take into account lake effects on propagation. 

 

- Trip

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Not in 2016.  Not in 2017.  Look to a 2018-2020 timeframe -- at the earliest.  ATSC 3.0 will require a new set top box/tuner distribution program.  We already went through that process with the DTV transition just a few years ago.  It will be a few more years before we hit the reset button and do it again.

 

And I realize that with another ATSC standard, it might as well future proof with 4K.  But 4K OTA, honestly, is superfluous.  Get all 1080i/60 up to 1080p/60.  That is a more sensible goal.  Interlaced scan no longer has any place in 2016 and beyond.

 

AJ

 

DTV was mandatory though.  So a voucher program made sense.  I doubt ATSC 3.0 is going to be mandatory?  ATSC 3 should have been ready when 4K TVs got cheap. :-(.  That way the market could be getting seeded already with built in tuners.  4K sets are so cheap now.  

 

And most importantly, will there be enough bandwidth to provide 4K after the loss of 600MHz? If there was enough spectrum out there, only the big network names will be in 4k.  They could have duplicate stream on another channel but it be the 4k channel. Wouldn't have to go through any distribution program. 

 

But if there isn't enough spectrum to have duplicate dedicated 4k streams, seems like a transitional period would be a lot more complicated than DTV was.  

 

 

 

As far as 1080p content goes, tell that to satellite and landline providers. :-P 

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DTV was mandatory though.  So a voucher program made sense.  I doubt ATSC 3.0 is going to be mandatory?  ATSC 3 should have been ready when 4K TVs got cheap. :-(.  That way the market could be getting seeded already with built in tuners.  4K sets are so cheap now.

Not everyone will have a 4K TV soon.  Not even close.  Heck, current 4K TVs are not ATSC 3.0 tuner compatible.  The FCC and broadcasters cannot just screw over most of the installed OTA TV base.  A tuner/converter voucher system will need to be implemented.

 

And most importantly, will there be enough bandwidth to provide 4K after the loss of 600MHz? If there was enough spectrum out there, only the big network names will be in 4k.  They could have duplicate stream on another channel but it be the 4k channel. Wouldn't have to go through any distribution program.

One, the 600 MHz incentive auction has not yet happened. It still may fall flat on its face. Two, even if/when 600 MHz UHF gets refarmed to mobile, that has no effect on the remaining channels below the 600 MHz band.  You seem to assume that 4K will be broadcast in greater than the 6 MHz legacy channel bandwidth, thus require multiple RF channels.  That is highly unlikely.  Any 4K OTA will stick to the same RF channel bandwidth as ATSC and NTSC before it.  Congress no longer will allow the FCC to hand out additional RF channels for free -- especially just for 4K.  And broadcasters will not pay for additional RF bandwidth.

 

AJ

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Not everyone will have a 4K TV soon.  Not even close.  Heck, current 4K TVs are not ATSC 3.0 tuner compatible.  The FCC and broadcasters cannot just screw over most of the installed OTA TV base.  A tuner/converter voucher system will need to be implemented.

 

One, the 600 MHz incentive auction has not yet happened. It still may fall flat on its face. Two, even if/when 600 MHz UHF gets refarmed to mobile, that has no effect on the remaining channels below the 600 MHz band.  You seem to assume that 4K will be broadcast in greater than the 6 MHz legacy channel bandwidth, thus require multiple RF channels.  That is highly unlikely.  Any 4K OTA will stick to the same RF channel bandwidth as ATSC and NTSC before it.  Congress no longer will allow the FCC to hand out additional RF channels for free -- especially just for 4K.  And broadcasters will not pay for additional RF bandwidth.

 

AJ

 

So maybe we won't get any 4K potentially.  I know that 4K won't require the use of a second channel.  CES showcases that 4K can easily get it done in one 6MHz channel.  But, I don't know what the bitrate is/was.  If 4k is such that broadcasters would need to drop subchannel networks, they may not want to do that.  And if they are unwilling to pay for a channel dedicated for 4K.  Unless codecs get good enough such that a channel with 4K can handle some 480p subchannels.  

 

I know 4K TVs aren't ATSC 3.0.  3.0 isn't even finalized.  I was saying that 3.0 should have gotten finalized by the time 4K got super cheap.  You can get a 4K TV for just a few hundred bucks now.  

 

If Congress won't let the FCC handout whitespace spectrum for 3.0 use, then why would Congress fund a voucher program unless they force the broadcasters to update to 3.0 by law.  The only reason why there was a voucher program before is because it was law to change to DTV.  You think it will be law to change to ATSC 3.0?

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I have a few minutes, so I'll address a few things here about ATSC 3.0.

 

This post may contain opinions.  Those opinions are my own and do not reflect those of the FCC or its commissioners.

 

First of all, the original DTV transition was requested by broadcasters as a means of getting them into the digital age.  Each broadcaster was assigned a second channel with the understanding that at the end of the transition, they would relinquish one of the two and the TV band would be shrunk by about 100 MHz, some of which is now found as Bands 12, 13, 14, and 17, among others outside the US.  Since that spectrum shrinkage would result in auctions and became Congressionally mandated, money was available to pay for the voucher program.

 

The 600 MHz auction envisions buying out some TV stations and moving the remainder to lower channels to clear the top ones for auction.  Congress has not mandated a transition to ATSC 3.0 as part of this, and it was not requested by broadcasters like the original DTV transition, which is also why there is a reimbursement fund for broadcasters that did not exist in the DTV transition.  Combining a move to ATSC 3.0 would increase the cost to government, not decrease.

 

As such, any transition to ATSC 3.0 is going to be voluntary, and on the stations' dime.  There will be no second channels involved; private agreements between broadcasters will make any transition to ATSC 3.0 happen. 

 

Imagine, for a moment, that you have three stations, A, B, and C, all currently broadcasting in ATSC 1.0.  As the transition starts, station C converts to ATSC 3.0.  Its programming is now aired on A and B.  C, meanwhile, carries the programming of A and B in ATSC 3.0, so a viewer who converts to ATSC 3.0 can get all of the programming on both.  The added efficiency of ATSC 3.0 makes this possible, as long as we're not talking about 4K, and just existing HD standards.  Then, after a while, a significant number of people have the receivers.  Station B now converts to ATSC 3.0 as well.  Some of the subchannels from all three disappear, but the main streams from stations B and C now also appear with the programming of A on A's signal.  Meanwhile, A's programming is carried on B and/or C in ATSC 3.0, and new services on ATSC 3.0 can begin.  Finally, when you get almost everyone watching ATSC 3.0, now you convert A, and everyone is in ATSC 3.0.

 

Another note is that if you've used the HDHomeRun receiver, I suspect something like this is envisioned as the converter box of the future.  Essentially, you would have your antenna hooked to a receiver near the antenna, then apps either on a smart TV or smart device like a Roku or smart phone in the home would be able to stream the programming from the receiver.  This would eliminate the need for a box at each set, assuming the set has smart functionality.

 

None of this addresses your original question about 4K though.  The short answer is, we don't know.  Personally, I don't find 4K to be very impressive in the way HD was over SD, and I don't think most people will think so.  Where ATSC 3.0 will be important is in providing more content in the existing SD and HD formats and, potentially, transmitting to mobile devices.  The auction may reduce the number of stations overall but if the transition occurs, it won't be a major obstacle, I don't think.  If anything, it will allow stations to replace any lost TV stations with additional programming through increased capacity in the long term.

 

- Trip

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...And most importantly, will there be enough bandwidth to provide 4K after the loss of 600MHz? If there was enough spectrum out there, only the big network names will be in 4k. They could have duplicate stream on another channel but it be the 4k channel. Wouldn't have to go through any distribution program.

...

Just wanted to mention that 4K will be using HEVC encoding which is way more efficient than the MPEG-2 used for current HD broadcasting.

Edited by GoWireless
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If that's true, then both them and the 850MHz wireless carriers need to start paying. 

 

Paying what?  Once a license is awarded, other than regulatory and renewal fees, that's it.  Sprint doesn't spend billions of dollars every year on spectrum licenses they hold.  What they paid for it, versus current valuation, is irrelevant.

 

If I gave you a baseball card 10 years ago for free, then today it turned out to be worth millions, would you owe me money?

 

Not to mention that TV broadcasters have piles of regulations on them that do not apply to wireless companies, such as E/I programming, public files, public access to the studio, local programming, indecency rules, etc.  Those things aren't free.

 

- Trip

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