As many of you know, analog television broadcasting in the US will end on February 2009. Of course, the television networks refuse to let you forget this, constantly telling you that if you are using an old fashioned over the air antenna (rabbit-ears) to receive TV, you better get a converter box. They don't want to lose their valuable viewers.
Of course this is false; rabbit-ears aren't the factor at all; it's the receiver that's in your television. But I'm sure there will be folks that will panic about this and get converter boxes they don't need even though they have a new set.
That's not what I'm going to talk about, though. I'm going to talk about ATSC itself.
ATSC is a neat little standard. You can transmit a 19 megabit signal in the space that an old fashioned analog television channel used to use. You can support multiple sub channels, and resolutions up to 1920x1080 (1080i) high definition. However, there is a force at work that will probably lead to more frequent television receiver upgrades than you might have been used to.
The original television standard, NTSC, was pretty much static from the 1950s until today. The technology remained backwards compatible; heck you can use a 1960s television to watch today's analog broadcasts. However, digital technology is constantly improving at a high rate dictated by Moore's law and software design. Right now ATSC uses MPEG-2 transport streams to transmit television signals. MPEG-2 is already a fairly obsolete codec which requires much more bandwidth for a given image quality than newer codecs like h.264 AVC.
Since broadcasters want to cram more and more channels into an already tight spectrum, there will likely be a push to move to more efficient codecs in the future as technology marches on. Do you really think you're going to be using MPEG-2 transport streams to watch television in 2025? I'll bet you $1000 that you won't be.
There are three possibilities, really. The first is that broadcast television will stagnate. They will keep using the current ATSC standard to transmit the few, limited channels we already have and the spectrum use will become less efficient as time marches on. The second is that broadcast television will eventually die, and be fully replaced by cable TV and direct broadcast satellite systems. With these systems, upgrading the codec used is as simple as upgrading the set-top box. As codecs improve we can keep packing more and more channels of rubbish into the same space. The third possibility is that we're going to be upgrading our televisions every 10 to 15 years as new codecs are added to the ATSC standard. I wouldn't put it past the industry making people do this.
And the most amusing thing about all of this? There still won't be much of anything worth watching on television. Why do media companies think more channels is better? I'd be happy with five channels if the programming were decent.
And that's my geeky outlook on television standards. Carry on...