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Than analog TV:

http://www.msnbc.com/news/752048.asp?0si=-&cp1=1

Quote:
The Federal Communications Commission requires the upgrades from analog to the more-efficient digital technology because HDTV uses about four to five times less bandwidth on the broadcast spectrum. The FCC wants stations to return the analog signal leases to the government by 2006.
Also, from their interactive demo to the left:

Quote:
Few cities now have operational HDTV stations.
You have to wonder if these reporters even leave their desks to write this

stuff.


The things you learn if you read regularly !
 

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Caught that momentary puzzler this morning, too. Just seems like an 'inverse' of describing how it's normally put. Both NTSC and HDTV require a 6-MHz broadcast channel. HDTV, as CBS likes to put it, delivers some 6 times more detail (or 4-5 times, if you prefer; pinning it down gets into minutia quickly). Guess you could say that a PBS digital station putting five standard channels within 6 MHz is doing that.


Fox could use its 6-MHz channels for true 1080i or 720p HDTV, which requires sampling a scene or film originally at HDTV resolutions and sending those details along to viewers. Instead, if Fox or other stations don't transmit original HDTV resolutions, but take 480 signals and boost them (upconvert) to 720p or 1080i, or transmit 480p, that's not HDTV (16X9 at true 720X1280 or 1080X1920). It's upconverted 480, or enhanced or extended SDTV (such as 480i/p X 704 ). -- John
 

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Maybe he meant it takes 5 times less bandwidth to deliver a given resolution digitally? Who knows. But of course that wouldn't do anything lessen the frequencies used, since they get their 6Mhz whether they use it all or not.
 

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If you take the "H" out of "HDTV" there's almost a grain of truth in the statement.;)


Its true that, with multicasting, you could get three or four standard-defintion programs with quality that's comparable to one NTSC program using the same 6 MHz of spectrum. Hell, with improved encoding in the future maybe 5, who knows?
 

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DTV transmission does not require the vacant guard channels around every active channel as does the present analog system. In practice, the analog system requires more like 18 mHz of spectrum for each channel.
 

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Good point.
 

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"HDTV uses five times less bandwidth..." than [email protected] stereoscopic computer graphics.


Now that's a statement that makes sense, almost.
 

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Direct TV's signal from the sat is already compressed and digitized (even the analog channels) just not in HD, so it already takes up less bandwith than the OTA HD signals
 

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You can transmit four, maybe five SD programs in the same 6 Mhz bandwidth that will only accommodate one in analog. HD would require about 30 Mhz to transmit in analog. The increase in efficiency gained by broadcasting digitally is the government's main reason for pushing the transition.
 
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