[opendtv] Re: The "real" problem with OFDM in the U.S.
- From: Tom Barry <trbarry@xxxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Sun, 06 Mar 2005 21:41:46 -0500
> I'm not sure what would have been a more appropropriate
> stategy.
If it was not desirable to suddenly allow longer range reception then
possibly they should have chosen a strategy that focused more on highly
reliable indoor reception with set top antennas. It just seems silly to
design a new system with a criteria that it cannot surpass the old one.
And in this day and age a high tech system with that goal cannot
survive. I still maintain it was a DUMB choice.
- Tom
Manfredi, Albert E wrote:
> Tom Barry wrote:
>
>
>>Yes, I guess that is true but it's such a bad decision I
>>wish we wouldn't perpetuate it.
>
>
> Not quite the case. FCC 96-317 (from 1996)
>
> ftp://www.fcc.gov/pub/Bureaus/Engineering_Technology/Notices/1996/fcc9631=
> 7.pdf
>
> summarizes past decisions and makes new rules. One of the new
> proposals, by the way, was to add VHF into the spectrum
> available for ATSC, but to limit DTT to channels to 7-51.
> Before that, only UHF was being considered for ATSC.
>
> Anyway, on the subject of coverage, the FCC had to establish
> a frequency plan for DTT, which included questions of
> radiated power and antenna height. So they had to set down
> criteria for the new ATSC service.
>
> To do this, you need an objective. The objective proposed
> in this document was to equal NTSC (grade B) coverage of the
> analog signal of each station with the digital signal of
> that same station. Now the FCC could figure out how much
> signal the DTT stations would need to transmit, and how to
> prevent interference with other markets and with existing
> NTSC stations.
>
> Greater than NTSC coverage would be gravy. But that couldn't
> be allowed if it created interference. So this is NOT a
> question of "no greater than NTSC," but rather "at least as
> good as NTSC," subject to a set of (sensible) constraints.
>
> I see nothing bad about any of this. It seems quite logical.
>
> Anyway, here's the part that addresses coverage compared with
> NTSC. Notice the part about going beyond this amount of
> coverage, as long as it didn't interfere with other signals:
>
> -----------------------------
> 13. Proposal. In reviewing this issue, we agree with those in
> the broadcasting industry who have argued that replication of
> existing service areas in the new DTV allotments offers
> important benefits for both viewers and stations. Replication
> would generally maintain the 19 service areas of existing NTSC
> stations, thereby preserving viewers' access to off-the-air TV
> service and the ability of stations to reach the audiences
> that they now serve. Accordingly, we are proposing to identify
> digital TV allotments that, to the extent possible, will allow
> all existing broadcasters to provide digital TV service to a
> geographic area that is comparable to their existing NTSC
> service area. In this regard, we also propose to specify for
> each DTV 21 allotment a maximum permissible effective radiated
> power (ERP) and antenna height above average terrain (HAAT)
> that would, to the extent possible, provide for replication of
> the station's existing service area. Furthermore, as discussed
> below, we are proposing to allow stations to maximize or
> increase their service area where such an increase would not
> create additional interference. (Footnote 22)
>
> 14. We request comment on all aspects of our proposal to use
> the service replication plan in allotting and assigning initial
> channels for digital TV service. We also request comment on
> whether it might be more desirable instead to adopt our
> original plan to allot DTV channels using an approach that
> maximizes the service areas of all DTV stations. This approach
> would tend to equalize the coverage areas of all stations
> within a market and reduce the current disparities among
> stations. We request comment on whether our original approach
> would be more appropriate and would provide more incentives for
> broadcasters to implement digital service more quickly than the
> service replication approach.
>
> Footnote 22. Stations would be permitted to increase their
> power and antenna height up to that permitted for maximum
> facilities, as discussed below in Section IX.
> -----------------------------
>
> I'm not sure what would have been a more appropropriate
> stategy.
>
> Bert
>
>
> ----------------------------------------------------------------------
> You can UNSUBSCRIBE from the OpenDTV list in two ways:
>
> - Using the UNSUBSCRIBE command in your user configuration settings at
> FreeLists.org
>
> - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
> unsubscribe in the subject line.
>
>
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
