[opendtv] Re: Digital TV: Brazil to Adopt Anything But the American System
- From: Tom Barry <trbarry@xxxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Sat, 11 Feb 2006 21:11:00 -0500
Indoor and mobile reception will be necessary for the future survival of =
(free or not) OTA TV. Of course even that will be threatened eventually =
by mega-broadband 2-way fiber with pervasive wireless hot spots.
I think OTA TV is really just legacy multi-casting but there is still no =
reason the broadcasters can't move into the future as technology advances=
=2E
- Tom
Albert Manfredi wrote:
> Ian Mackenzie wrote:
>=20
>=20
>>Doug
>>
>>Your'e the one who is deluded. You have been blowing this trumpet
>>for years and the tune is a little old now. Why don't you admit that
>>ATSC is the one out of step with the rest of the world.
>=20
>=20
> Just like NTSC was, and is. Come guys, let's not fight.
>=20
> Doug is right to argue that ATSC does not mandate use of outdoor antenn=
as,=20
> any more than DVB-T does. John Shutt keeps referring to the antenna mou=
nted=20
> on a 30' mast as if that were a requirement for ATSC. It might have bee=
n=20
> used as a planning factor, but once again, "compared to what"? We shoul=
d=20
> always ask compared to what?
>=20
> John and other might be surprised to know that the French TNT (televiso=
n=20
> numerique terrestre) also uses a 30' mast planning factor (actually 10 =
> meters, but who's quibbling).
>=20
> Here's a little gem I found:
>=20
> --------------------------------------------
> http://www.csa.fr/pdf/Rapport-GT2-Aspects_Radiofrequence_de_la_TNT.pdf
>=20
> En France, le CSA a effectu=E9 la planification des fr=E9quences en pre=
nant=20
> comme hypoth=E8se l=92utilisation des param=E8tres suivants :
>=20
> Modulation : 64 QAM
> Rendement de code : 2/3
> Mode de r=E9ception : fixe (canal de transmission de type Rice)
> Mode : 8k (6817 porteuses)
> Intervalle de garde : 28 μs (Tu/32)
> Rapport du groupe CTE-TNT/GT2 =AB Radiofr=E9quence =BB doc. GT2-78
>=20
> Avec ces param=E8tres, le niveau de champ m=E9dian minimal =E0 planifie=
r1 =E0 une=20
> hauteur de 10 m par rapport au sol est de 53 dBμV/m en bande IV et=
de=20
> 57 dBμV/m en bande V.
> -----------------------------------------------
>=20
> So, the planning factors assume 64 QAM, 1/32 guard interval (which mean=
s=20
> very short distance between the towers of an urban SFN), Ricean fading =
> (which is relatively benign), and the power density measured 32.8' abov=
e=20
> ground level.
>=20
> No one should conclude from this that indoor reception is impossible. B=
ut=20
> everyone should conclude that if coverage area is calculated on this ba=
sis,=20
> then indoor reception will certainly not be guaranteed for everyone in =
the=20
> market area.
>=20
> Just like here in the US.
>=20
> Bert
>=20
> _________________________________________________________________
> Express yourself instantly with MSN Messenger! Download today - it's FR=
EE!=20
> http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
>=20
> =20
> =20
> ----------------------------------------------------------------------
> You can UNSUBSCRIBE from the OpenDTV list in two ways:
>=20
> - Using the UNSUBSCRIBE command in your user configuration settings at =
FreeLists.org=20
>=20
> - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word =
unsubscribe in the subject line.
>=20
>=20
----------------------------------------------------------------------
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:
