[opendtv] Re: (No Date: Tue, 28 Sep 2004 10:30:37 -0400

  • From: Terry Harvey <tjharvey@xxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx, <opendtv@xxxxxxxxxxxxx>
  • Date: Thu, 14 Oct 2004 21:39:24 -0700

The modulation mode in PSIP is simply a number: if needed a 'COFDM' 
modulation mode number could have been included under the modulation 
mode.  The modulation mode is therefore a non-issue. I feel the issue is to 
ensure that there are no conflicts is the PSIP/ DVB-SI schemes.

Recall that ATSC A/58 from 1996 is the "ATSC/DVB Harmonization" 
recommendation. Note that it was the basis to provide some sort of harmony 
to minimize table conflicts between ATSC and DVB. Also note that many ATSC 
broadcasters still ignore the recommendation in A/58 not to use 'Program 1' 
in A/58.

Terry Harvey



At 07:41 PM 10/14/2004 -0700, John Willkie wrote:

>For each virtual channel emitted in the 8-VSB, there is a modulation mode
>parameter.  There are provisions in A/65 for analog and digital services,
>and NTSC and 8/16 VSB modulation.  In ATSC A/81 (satellite ATSC) there are
>provisions for a variety of modulation modes.  No provision for COFDM.
>
>You asserted that COFDM could have been permitted without any change in
>PSIP. I challenged that.
>
>The problem is symmetrical: there is no provision in DVB-SI for NTSC or 8/16
>VSB.
>
>So, they both don't recognize the other.  To make COFDM useful in TV sets
>that also support VSB, there has to be common ground in the metadata
>schemes, beyond MPEG-2 SI (PAT) and PSI (PMTs).  I also am unaware of any
>way at the MPEG-2 level to signal modulation mode -- that's effectively
>"user private" with the users being DVB and ATSC.


 
 
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