In a message dated 1/10/2004 9:48:13 PM US Mountain Standard Time, 
Plug@BryceCo.Net writes:

the very same reason why the FCC is mandating DTV, the digital signal
will weaken with distance but it will not degrade; a one is still a one
and a zero is still a zero no matter how faint. 

It will degrade because there has to be a bound on what consitutes 1 and 0 to 
differentiate data from noise.  If you can't make out a "1", it's degraded.  
Also note that you could have "additive" RFI-- like the white lines you get if 
you turn the vaccuum on near the TV

The story I hear is that DTV is more efficient on spectrum (the current space 
for 1 analogue channel can have 4 digital ones of equal quality), so they 
want to sell off a lot of spectrum (I believe 20 channels worth or so).