Re: FCC Orders All TV's To Have Digital Tuners By 2007

[Garrett Wollman <wollman@lcs.mit.edu>]

<<On Sat, 10 Aug 2002 21:03:13 -0400, "Aaron 'Bishop' Read" <aread@speakeasy.net> said:

> Yes and no...as long as we're being "nitpicky"  (I prefer to think of it as 
> "thorough" :-)  IBOC stands for In-Band, On-Channel.  That's a reference to 
> the fact that the IBOC signal is both in the same band as the analog 
> signal, and also on the same channel (frequency).

It's only ``on channel'' if you redefine the channels to be 20 kHz
wider than they currently are.  However, in the whole murky history of
this mistake, ``in-band adjacent-channel'' refers to something
different: an independent carrier with center frequency the same as an
adjacent AM channel.  The perpetrators of this mess chose the wording
``on-channel'' to emphasize the fact that their digital carrier is
designed to coexist with traditional AM on the same center frequency.

There were, as I recall, four main proposals for coexistance:

- in-band on-channel (i.e., what iBiquity is pushing)
- in-band adjacent-channel
- in-band alternate-channel (e.g., the DTV transition plan)
- out-of-band (e.g., what the rest of the world is doing)

-GAWollman