Comment by wmf
1 day ago
I heard in some European countries they packed digital SD channels into less spectrum (one 6 MHz channel can carry 4-5 TV channels). We should have done that here instead of broadcasting HD.
1 day ago
I heard in some European countries they packed digital SD channels into less spectrum (one 6 MHz channel can carry 4-5 TV channels). We should have done that here instead of broadcasting HD.
That's already widely done in the US.
If you plug in an antenna and scan for local channels, what used to be one analog TV channel on colloquially-named "channel 7" in the defined channel 7 frequency range will now be seen as "channel 7-1" which is often (but not always!) actually broadcast on the old frequency. During the ATSC transition, it was important to retain the branding and consumer memory of "channel 7" even when the RF transport frequency changed.
The transition opened the ability to have an arbitrary number of digital subchannels, 7-2, 7-3, etc etc. The total bitrate available on a given ATSC broadcast is fixed, but it can be partitioned among multiple MPEG streams. The typical setup is one (occasional two) HD channels and several SD channels. Obviously there's a balancing act between bitrate and visual quality for each subchannel. It's often used as a way to broadcast older (read: cheaper) syndicated SD content on which they can run more ads while keeping the main HD channel quality reasonably acceptable.
That's not what I'm talking about though. We should have repacked ABC, NBC, CBS, and Fox onto a single channel.
Seventeen years ago, when we transitioned, the state of available and deployed equipment, codecs, and home receivers would not have permitted it.
I mean sure, you could pack four streams into one 6MHz channel. They could even be "HD" insofar as the transmitted stream is 720p or 1080i.
The result would have been MPEG-2 program streams of about 4.5Mbit each instead of about 18-19Mbit (assuming no other subchannels). That would make live sports or anything with significant motion look like absolute dogshit.
You might say that you don't care about that, and that is fine for you. However, in that case, I would respectfully submit that opinion to be far from the center of the bell curve of television-viewing American public of that era.
We could do a lot better with ATSC 3.0. So, there might someday be a second round of broadcast frequency reclamation, just as there was with ATSC 1.0.
5 replies →
Atsc 3.0 does this in a lot of areas, it is in my area, all the channels are multiplexed from one broadcast, although it's hard to tell on the tv since you get the virtual channel numbers that are different and the same as the atsc 1.0 channels
1 reply →
If you're gonna smash everything onto a single channel, you may as well turn the whole thing off.
Gonna look like absolute trash. Might be almost acceptable with atsc 3, except for the diaster of DRM and new proprietary audio codecs that brings.
Here in the US I get PBS on Channel 10 - there's 10.1 (straight PBS), 10.2 (PBS-World) and 10.3 (PBS kids) - do each of these take a separate 6MHz bandwidth, or are they packed into that single 6MHz bandwidth like in Europe?
Yeah, that's one channel. IMO it's wasteful to give PBS an entire 6 MHz.
Why shouldn't they get 6 MHz? My PBS station broadcasts 4 subchannels: the main PBS channel, PBS Kids, a channel with programming about our local region (which airs live coverage of our state legislature when it's in session), and a loop of weather information with audio from the local NOAA Weather Radio broadcast. Those are all useful public services. PBS Kids in particular I think has a very good reason to exist, considering the absolute wasteland that is young children's media on streaming.
ESPN, however, demands that they get the full 6 MHz.