Posts Tagged ‘FCC Spectrum Auction’

Spectrum Repacking and Channel Scans

In the wake of last year’s big spectrum auction, the FCC is chopping even more spectrum away from UHF TV stations and expecting (somehow) to jam all the remaining TV stations into low band VHF (2-6), high band VHF (7-13), and truncated UHF (14-36) channels.

In my neighborhood, stations are already packing up and moving. While conducting a recent test of a “smart” indoor UHF TV antenna, I grabbed some spectrum analyzer plots of all three television frequency bands. As expected, the RF spectrum from channel 56 to 87 (channels 2-6) was largely unusable due to high levels of impulse and main-made noise.

The high band VHF spectrum wasn’t much better, with some continuous RFI kicking up the noise floor by almost 20 dB. But it was the UHF spectrum I was interested in, and several former broadcasters were noticeable by their absence. Channels 29, 35, and 39 – previously in use for Univision, independent, and PBS stations – had all gone dark.

To get around the lack of available channels, TV stations are “channel sharing,” something the FCC frowned on as recently as a decade ago. What that means is that stations divvy up the available bits in an MPEG2 encoder and multicast several minor channels on one physical RF channel. This technique was almost impossible to pull off twenty years ago when digital TV broadcasts and HDTV were just getting started.

Now, thanks to very powerful processors and tricks like adaptive variable bitrate encoding and statistical multiplexing (a/k/a “stat muxing”), it’s not difficult at all, even though the jury is still out on the quality of HD and SD video using much lower bit rates that were not possible in 1998. NBC has done this in Philadelphia and New York, combining Telemundo channels with NBC programming and making room for one HD service from each.

Locally, an independent station in Allentown (WFMZ) will relinquish its 5-megawatt signal on UHF-46 and move to VHF-9, sharing bits with WBPH and the Lehigh Valley PBS station, WLVT (formerly on channel 39). This will have happened by the time you read this column and I’ll be curious to see just how much image quality has deteriorated for each minor channel after the new transmitter lights up.

Keep in mind that many stations auctioned off their channels in return for a nice pay day. Public stations in particular pocketed some serious change, money that went into facilities upgrades and balancing their budgets. If their multicast services hold up well with the latest in MPEG2 encoding, then they’ll come out of this smelling like a rose.

What this means to you as an OTA viewer is that you will need to re-run channel scans to catch all of these moves – otherwise, you’ll tune to a channel that has gone dark and will be standing there, scratching your heads in bewilderment. I’d perform a channel scan twice a month from now through the end of the year. (You might also pick up some newer, low-power translators and repeaters along the way, and you may find some channels are gone for good.)

Broadcast TV Spectrum Repacking: The Devil Is In The Details

The FCC has concluded its spectrum auction, and although the winning bids generated only about ¼ of what was expected, plenty of TV stations will be moving to new channels.

But there’s a catch. And you probably won’t be happy when you hear about it.

Currently, the majority of TV stations broadcast in the UHF television spectrum from channels 14 to 51. Another smaller block of stations use the high band VHF channels (7 through 13) while fewer than 50 stations transmit on low band VHF channels (2 through 6).

That is certainly going to change, as it appears all UHF TV channels above 37 will be re-allocated for a variety of services, including Wi-Fi, mobile phones, and a bunch of other “white space” operations. There may even be a few TV stations still mixed in with these services, and we won’t know how broadcasters will be re-packed until early April.

Finding new channels for broadcasters who gave up their channels in return for some nice cash will be a pain in the neck. And it will certainly require some stations to move back to those low-band VHF channels, which were once desirable back in the early days of television (Channels 2 and 3 were ‘golden’ then), but now make up what’s essentially the low-rent district of TV broadcasting.

Why? First off, much larger antennas will be required to receive these stations. A full wavelength at 56 MHz (channel 2) is about 5.4 meters, or about 17.5 feet. So a somewhat-efficient ¼-wave whip antenna to pull in that channel needs to be about 4.4 feet long. (Now you know why grandpa and grandma’s TVs had those long ‘rabbit ear’ indoor antennas!)

That’s not to say you can’t pick up these channels with smaller antennas – if the signal is strong enough, you probably can. But that means being much closer to the transmitter than you’d need to be with a high-band VHF or UHF signal, as it’s easier to design antennas for those channel that have some gain.

Here’s another problem. The spectrum from 50 to 88 MHz is historically plagued with interference from impulse noise (vacuum cleaners, electric motors, switching power supplies, lightning and other static). And during certain times of the year, atmospheric enhancement of radio signals occurs where distant stations will come in stronger than local stations, creating plenty of interference (ionization of the E-layer of the troposphere, a/k/a “E-skip”).

While the high-band TV channels are also susceptible to man-made and natural interference, it’s not as much of a problem. And UHF TV signals are essentially immune to impulse noise, although they can also experience signal ‘skip’ conditions; particularly in the late summer and early fall with tropospheric ducting.

During one of my RF and wireless classes at InfoComm, we aimed an antenna from the 2nd floor North Hall meeting rooms toward Black Mountain, a line-of-sight path parallel to the Las Vegas Strip, to try and bring up channel 2 (KSNV). Guess what? We couldn’t even find the signal using a spectrum analyzer, due to all an extremely high noise floor of about -50 dBm. (The noise floor at my home office is about -88 dBm, which is moderately quiet.)

Reception of channel 2 became such a problem for KSNV that they eventually relocated to UHF channel 22, where they can easily be picked up with an indoor antenna. But other stations won’t be as fortunate, as the spectrum will be fully packed after this year with no place to move for a ‘do-over’ if reception is a problem.

When the DTV transition happened in June of 2009, three stations in Pennsylvania, New York, and Connecticut had to move to channel 6. It became apparent very quickly that DTV converter boxes weren’t selective enough to reject interference from nearby high-power FM broadcast stations. So WPVI in Philadelphia and WRGB in Schenectady applied for and got permission to double their transmitter power in hopes of fixing the problem.

WPVI’s signal on channel 6 is having a hard time up against the many Philly-area FM stations just higher in frequency.

You can see how much of a challenge this downward move will present to people using indoor antennas. Figure 1 shows how WPVI’s 8VSB carrier looked when I tested the Antennas Direct ClearStream Eclipse loop antenna with an amplifier, while Figure 2 shows channels 9 and 12 with the same rig – but a much lower noise floor. Note the strong FM stations immediately to the right of WPVI, a potential source of interference and receiver overload that would not be an issue on high-band VHF and UHF channels.

This view of WBPH-9 and WHYY-12 shows both carriers standing tall above the noise floor (about -85 dBm) and easy to receive.

Figure 3 shows a bunch of UHF channels received the same way – the Eclipse has some resonance at these frequencies as it is close to a full-wave loop antenna, so indoor reception is relatively easy.

Pulling in UHF TV stations is a much easier task for a small indoor antennas like the Eclipse. A low noise floor (-87 dBm) doesn’t hurt, either.

I have two pretty sophisticated rooftop antenna systems (one on a rotator) and I have trouble picking up KJWP-TV in Philadelphia on channel 2 – the signal breaks up frequently and there’s lots of broadband noise showing on my spectrum analyzer when I point the antenna in that direction. There’s also a station on channel 4 (WACP) that pops in from time to time, although in the other direction toward New York City.

If a station you like to watch has to relocate to the low-rent district, you may need to spring for a better antenna, and it might be larger than some of the indoor models you’re used to seeing. If you are 20 or more miles away from the transmitter, you can forget those small picture frame or box-shaped models – they won’t work.

You might even have to (“gasp!) go back to using a pair of rabbit ears. Yes, they still make these; I found a pair in Best Buy the other day for about $15. Or it might be time to consider an outside antenna, and even that will have to be larger.

I’ll have more news once the spectrum repack is done later this month, and the FCC usually provides a link to a listing of TV station channel assignments. If you live near a large city where most of the high-band and low UHF channels are Being used by major networks, you’re probably not going to see much in the way of musical channels.

But if you live in a market where all of the active channels are on UHF – say, like Syracuse, NY or Scranton/Wilkes-Barre, PA – don’t be surprised when you can’t pick up some of those stations in the future. They might have moved down the street…




One Man’s Junk IS Another Man’s Treasure!

Next March marks a defining moment in the history of broadcasting: The Federal Communications Commission will hold an auction to see if TV stations REALLY want to stay on their UHF channels, or sell their spectrum space off to the highest bidder and either (a) move to another UHF channel, (b) move to a VHF channel, high or low-band, or (c) just throw in the towel and be done with broadcasting for good.

I’ve been alive for enough decades to remember when UHF TV reception was mostly black magic, and stations located in that band (originally from channels 14 through 83) were desperate to get a few hundred viewers. Some TV markets found the only way they could get licenses for broadcasts was to use these forlorn, unwanted channels; Scranton, PA being one example.

For my senior thesis in college in the mid-1970s, I wrote about the FCC’s All Channel Receiver Act of 1962, which mandated that “…that apparatus designed to receive television pictures broadcast simultaneously with sound be capable of adequately receiving all frequencies allocated by the Commission to television broadcasting.”

In an era where the major networks (ABC, CBS, and NBC) had the “plum” low-band VHF channels and some high-band VHF channels locked up, UHF was the only place to go. And it cost twice as much to operate a UHF transmitter and achieve comparable signal coverage, but without enough viewers, it was difficult if not impossible to attract enough advertising.

A year later in graduate school, I followed up on this topic to see how effective the ACRA had been to accomplish parity between VHF and UHF TV stations. Truth be told, the picture didn’t start to look rosy for UHF stations until the 1980s, by which time the band had been truncated to channels 14-69. But TV tuner performance had improved markedly, and many public TV stations started lighting up as did some high-power independent stations, translators, and repeaters.

With the advent of digital TV in the early 1990s, interest in UHF broadcasting picked up as it was discovered that UHF DTV signals penetrated into buildings much better than VHF signals. And UHF signals didn’t require very large antennas – even a small bow-tie loop antenna was sufficient to do the trick.

As the digital TV transition wound on, successive generations of DTV receivers came to market, employing ever-powerful adaptive equalizers to overcome the effects of multipath. When the time came to make the move to DTV and abandon analog NTSC forever in 2009, many stations also abandoned the once-prized low band VHF channels (2 – 6) in favor of high-band channels or “low” UHF assignments.

So, in a period of about 50 years, UHF channels went from being worthless real estate to prime property. (Just like fracking!) And it wasn’t just broadcasters who coveted it – the mobile phone companies, led by the CTIA (Cellular Telephone Industry Association), CEA (Consumer Electronics Association), and service providers including Verizon, AT&T, and Sprint were also casting a covetous eye on these frequencies.

Their case was bolstered by former FCC chairman Julius Genachowski, who claimed as the DTV transition was happening that we were facing a “wireless spectrum crisis” and that at least 120MHz of broadcast spectrum needed to be freed up for “wireless services” to solve the problem. (Never mind that TV channels 52 through 69 had just been returned to the government by broadcasters as the 2009 transition took place).

Depending on whom you talk to, the percentage of Americans who still watch over-the-air (OTA) television measures as low as 8% and as high as 20% – and that skews differently by geographic location and ethnic group. Still; if you accept a practical number of 15%, it’s easy to see why there is increasing demand by wireless companies for those UHF channels.

Accordingly; seven years after the DTV transition, we will see an open auction where broadcasters can entertain bids for their channels, or conduct a reverse auction by setting a minimum bid and see who antes up. A few days before I wrote this column, the National Association of Broadcasters released the list of minimum bid prices posted for TV stations (many of whom are on VHF channels, surprisingly!).

And the buy-in prices are staggering. Want to buy CBS’ flagship channel 2 (physical channel 33) TV station in New York City? A cool $900,000,000 (that’s $900 MILLION) is the opening reverse auction bid. Down the street, Comcast’s WNBC-4 (physical channel 28) starts at $869 million. And both those prices are to take the stations off-air for good: To relocate WCBS to a UHF channel – if one can be found – will cost a bit less; just $675M, while WNBC will require about $652M.

How about Los Angeles? You can kick KABC-7 off the air for just $305M, although no one is exactly pining for high-band VHF channels to provide mobile phone service. KCBS’ UHF channel can be vacated completely for a minimum bid of about $545M, or moved to another UHF channel for around $218M.

There are also some relative bargains out there. KXGN in Glendive, Montana will pull the switch on its UHF station for just $1.2M. (That’s the #210 and smallest TV market in the 50 states.) In Watertown, New York (near where my father grew up), there are several VHF and UHF stations that make up the #177 TV market. You can move any of them off the air for $45M to $88M, with the highest reverse bid being that of the local PBS station.

What do these prices tell us? First off, it would appear that many major-market broadcasters aren’t all that interested in shutting down operations, based on their astronomically high reverse bid prices. That is good news for cord-cutters and automobile dealers; the latter being the #1 source of ad revenue for TV stations. The prices for relocating channels are much lower than those for turning off the switch, which means that both independent stations and network-owned stations still see quite a bit of value in holding onto a 6 MHz digital channel someplace.

Secondly, in an industry where just about every American has a mobile phone and where price erosion is the story of the day (two-year contracts are going the way of the dodo, and voice and text plans are basically free these days), the likes of Verizon and AT&T aren’t likely to shell out hundreds of billions of dollars to expand LTE services. But we may see new companies coming in to offer wide-area Wi-Fi service, although that didn’t work out in the past with WiMax.

Third, anyone whose living depends on wireless audio operations could be in real trouble if more UHF channels TV disappear. In some worst-case studies I’ve seen, we could lose everything above channel 26. Or maybe just everything above channel 44. Or, we might see some TV broadcasts relocated to open UHF channels, intermixed with LTE, Wi-Fi, and white space devices. And there will be new “duplex” guard bands in the reallocated spectrum. (In any case, the sacrosanct nationwide channel 37 will remain so – for now.)

The truth is; no one really knows how any of this is going to play out. Will media giants like CBS decide they don’t need to be in the TV station business anymore? How about CBS affiliates? Would ESPN decide to do subscription DTV broadcasts, direct to viewers? Would Comcast continue to operate its owned NBC TV stations? How will public broadcasters be affected? Can we really dovetail TV broadcasts and LTE networks together?

And what happens if the FCC doesn’t get enough stations to participate? How much spectrum are they really looking to recover from broadcasters? Have we seen the last of these TV spectrum auctions for a while? (Bear in mind the current FCC chairman, Tom Wheeler, once ran the National Cable Telecommunications Association (NCTA) and CTIA. Food for thought!)

Talk about March Madness! Stay tuned…