Watchin’ a bit of TV on Sunday evening, and had a few comments – what else is new, eh?
Saw a commercial for Bank of America, where a woman ducks her head into a barbershop and asks, “Is there a Bank of America ATM around here?” In response, the shop residents all tell her about the incredible number of ATMs located on that street – probably about a dozen.
Now, this brings up two questions: 1) if there were that many ATMs, how in the world did this woman miss them?! and 2) just how many ATMs are necessary on one street? I guess the installation of a dozen ATMs on one street explains why we pay $3 every time we use one.
While flipping channels to see what was on in high definition tonight, I was struck by this thought – bear with me, it’s convoluted.
The digital television standard (the over-the-air type) includes something called PSIP, or Program Stream Information Protocol. This data that’s sent along with the program contains such information as the program name, guide information, and channel number. It’s useful because all the long-held channel numbers that we identify with are changing as the digital transition happens. For example, channel 4 here in DC, WRC-TV, uses “NBC4” as it’s moniker. But their digital channel is 48. They’re going to lose that channel number they’ve had for more than half a century, as are almost all TV stations as the digital revolution moves them up the dial.
PSIP allows stations to present a different channel number than the actual one they’re broadcasting on. Example: WBDC in Washington is analog 50 and digital 51. They’ve programmed their PSIP data so that your set-top tuner will display “50” instead of “51”. All the stations in this area are doing this, so you can tune to “4” and get WRC… the tuner automatically maps this number to frequency 48. Make sense? To make it more confusing, DTV allows for “subchannels”, so a station can broadcast multiple programs on different subchannels, i.e., 48-1, 48-2, etc.
Well, here’s one problem I never thought of. For some reason, WBDC on channel 51 is mapping it’s one program stream to: 50-1, 50-2, 75-1, and 75-2. They’re broadcasting just one signal, but the PSIP makes it appear on four different channels of my tuner.
Now, imagine for a moment a new marketing plan for a TV station: to make sure that viewers can never escape your influence, you simply program the PSIP to make your channel appear 10 or 20 times on a viewer’s tuner. You get all the benefits of broadcasting on many different channels, without having more than one transmitter or station.
I’m sure this is just my fevered imagination, and no station would deliberately do such a thing. I’m sure the fact that I have 4 different outlets for WBDC is just a mistake.
Warning – PSIP also includes conditional access protocols so that you can be locked out of certain programs that are broadcast free over the public airwaves; and a protocol that allows a station to change your channel without your knowledge or permission. Like any technology, it has a positive side – During the Channel 4 news, they could set aside a portion of the newscast for local news from your county, and send a signal to your box to switch to, say, channel 4-3 where they show news for your county. That’s a useful function. But they could also change your channel to suit their own ends. It’s scary how this industry has shifted to make it harder and harder for people to just watch TV; putting so much emphasis on preventing people from watching or recording it and controlling how we access it. All this on frequencies owned by us…
Related gripe. I’m certain, but can’t prove without doing a study, that all of my favorite tv channels coordinate commercial breaks to preclude my surfing for real content on Discovery while History is airing commercial drivel.
A search by topic turned up little, but it can’t be coincidence tonight when Discovery, History, Travel, Biography, TLC, Wings and Science all had commercial breaks at the same times for an hour!
As the old timey magazine feature once said, “There oughta be a law!”
RDF
Ah, you’ be right there – they *do* coordinate commercial breaks to ensure that you don’t drift away from their program and off to another channel. In fact, one new twist is that advertisers “strip” commercials by buying a spot on several channels that will air at the same time on all of them, so when you surf you run into the same ad on every channel. This is possible because commercials, like the programs, are rigidly scheduled.
It seems to me that they ought to list commercial schedules right along with programs. That way I could be sure to be home for the next airing of my favorite ad.
Another insidious plot: making television programs start a minute early to capture your eyes before you change the channel.