From now until July, TV
broadcasters in the U. S. are in the final phases of a grand reshuffle of
broadcast frequencies that has been going on for several years. Unless you happen to watch TV the
old-fashioned way—by getting a signal from a rooftop or indoor VHF/UHF antenna
directly from the terrestrial broadcast transmitter—you probably haven’t even
noticed. But this is the tail end of a process
that began back in 2012, when the U. S. Federal Communications Commission (FCC)
auctioned off a slather of frequencies in the 600-700 MHz range to be used as a
part of the new 5G mobile-phone plan.
You may not think of the
radio spectrum this way (if at all), but it is a limited natural resource, like
fresh water or land. As humanity has
learned how to exploit it in increasingly effective ways, the value of various
parts of it has fluctuated, mostly upward, but not always. For the first seventy years or so of the
FCC’s existence, the agency treated the spectrum like the federal government
treated federal land: if you qualified,
you could just get some of it for free, and then it was yours to use or sell
just like any other private property.
This wasn’t always the best
or the fairest way to do things. Back in
the 1920s, when it wasn’t clear that radio would amount to much more than some
hobbyists annoying their neighbors with loud spark-gap transmitters, it seemed
like a reasonable approach. But by the
1950s, when radio and then television frequencies were valued on the private
market in the millions of dollars, politicians began to pull strings and the whole
thing got very complicated. For example, how much of a coincidence was it
that the application for a new TV station that then-Senator Lyndon B. Johnson wanted
to build in Austin in the early 1950s was the only application filed in that city? None at all, because everybody else knew that
LBJ was so connected in Washington that filing a competing application would be
a waste of time. So LBJ’s family became
the proud owners of the first TV station
in Austin in 1952, and the next TV station there didn’t open until 1965.
Eventually, laws were passed
so that the FCC could actually hold auctions to allocate new spectrum
frequencies. This change acknowledged that
the radio spectrum had value, and probably a better way to allocate it than political
influence was to sell it to the highest bidder.
And of course, technology
wasn’t standing still during this time, either.
When the first UHF TV band was opened in 1952, it was viewed as the most
wasted part of the “vast wasteland” of TV, in the words of a cynical
FCC commissioner. Originally it covered
the entire frequency range from 470 MHz to 890 MHz, with channel numbers
designated 14 through 83. Because a TV channel then occupied about 6 MHz, in
principle there was room for almost 70 channels in the UHF band. But for many years, that promise went largely
unfulfilled for technical reasons.
It was a considerable
challenge to early consumer-TV makers to build a UHF tuner, which is the
“front-end” part of the TV that takes the signal from the antenna and
converts it down to a reasonably low frequency to be demodulated and used. Those old UHF tuners were fussy, handmade
devices that you tuned with a continuously-rotating knob, like a radio
dial. And they were very subject to
interference from other UHF stations.
Because of these problems, the FCC handed out a whole lot fewer UHF
frequencies than it looked like at first glance you could fit in that huge
range, because if the spectrum got anywhere close to crowded, all the UHF
tuners would start picking up the wrong signals and everything would go to
pot. Also, UHF signals didn’t carry as
far as the lower VHF frequencies (channels 2-13), so a lot of early UHF
stations were local low-budget affairs that couldn’t afford anything better.
Technical times changed, as
they always do, and around 2000 the TV industry made its move to digital broadcasting. This change, plus advances in tuner design,
rendered the old super-cautious FCC allocations pointless. And with the advent of cable TV, the importance
of over-the-air broadcasting began to wane, and once tuning your TV became a job
for a computer, the channel numbers no longer had to be irrevocably fixed to
particular frequencies, as they had to be with electromechanical tuners.
Fast-forward to 2012. The new 5G mobile phone service plan includes
the use of a 600-700 MHz band that will allow base-quality service over a much
wider area than the current higher-frequency mobile phone cells permit. The problem was, there were still a lot of TV
stations in that frequency range, hanging on to their old UHF TV
allocations. The FCC made them a deal: if you let us auction off your frequency for
5G, we’ll either share some of the profits with you and you can take the money
and go off the air, or move to another frequency. Either way, we’ve got to clear this band for 5G. Kind of a spectrum-allocation eminent-domain
action, as it were. Some stations took
the money and quit. Others have been shifting
up and down the frequency spectrum in a ten-phase process that will be
completed by July of 2020. While this can
be a big deal for the broadcasters, involving costly new transmitters and transmitting
antennas, the most that even off-the-air consumers will notice is that a
station may go blank, but all you have to do is “rescan” your digital
TV, and it will automatically hunt for the new frequency and find it for you.
To a geezer like me, who
grew up having to get up off the chair and twiddle with the fine-tune control
on the TV tuner every so often, it all seems too easy. And there’s something odd about the fluid
shifting going on behind the scenes.
Back when a channel allocation was something to be proud of, stations
often incorporated their channel number in their logo. For example, in Fort Worth, the local independent
station was Channel 11, and their logo featured the two numeral 1’s as
two nattily-dressed guys in little white suits, complete with handkerchiefs in
their breast pockets (I may be imagining the handkerchief part, but you get the
No longer. It’s all as invisible as sewer pipes now, and
about as interesting to the average consumer.
But in case you were wondering where your off-the-air station went, this
may be part of the explanation.