[opendtv] Re: Opinion: Mobile TV's New Free Market Economy
- From: Bob Miller <robmxa@xxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Thu, 19 Mar 2009 16:24:12 -0400
If we are only talking about mobile/portable reception and the need
for compact antennas what are the issues?
How much research is going on with M/H? How far are broadcasters
willing to go as far as building out SFN's? How well or possibly will
8-VSB/M/H work with MIMO, SFNs and vertical/horizontal polariztion?
How does all this affect the data rate? What does it matter what
research is done on the single carrier modulation 8-VSB/M/H if we are
stuck with some current limitations by law and broadcasters are mostly
in sub 700 MHz and therefore even more problematic spectrum anyway? I
am asking because I don't know.
I have said before that I think broadcasters will have their current
spectrum taken from them if few are using it. And the more efficiently
others can use the spectrum, the higher the economic value, the more
pressure from others to demand that it be released for other uses.
A lot of effort is going into making "other uses" more efficient with
"other modulations". So I wonder if it is indeed all about frequency
and received power. As we know received power wasn't and I believe
still isn't modulation insensitive as per 8-VSB. You can have good
receive power and no reception in Queens for example with 8-VSB
especially mobile.
Is 8-VSB/M/H an orphaned modulation as far as research?
The former TV spectrum recently auctioned off will most likely be used
with LTE, OFDM based. I was wrong it seems, broadcasting will most
likely not be used. I guess the broadcast model is getting just to
lame. But the 700 MHz spectrum that Verizon and AT&T will use is very
limited and needs all the help it can get from MIMO, possibly
verticle/horizontal polarization, sectoring and SMALL antennas. WiMax
has a lot more spectrum and already is better able to use OFDM with
MIMO etc.
The point is a lot of research is going on to get the most out of the
spectrum they will use. The players are willing to spend lots of money
to build out small sectored cells to reuse the spectrum as much as
possible and STILL will need more, ever more spectrum and higher data
rates to satisfy demand.
And they need antennas that will allow the maximization of data rate
and fit into a cell phone.
On the other hand you have broadcasters willing to restrict themselves
to MPEG2, 8-VSB/M/H and a business plan that says it is too expensive
to build out an SFN. It may be too expensive now considering the
recession, four years to a decent election cycle and the steady
erosion of ad supported OTA.
Here is something interesting on the subject. There seems to be a lot
of energy going into OFDM modulation research. Is there anything like
this on the broadcaster 8-VSB/M/H side? As far as OFDM because or
research it seems that the size and shape may no longer be limited as
before by wavelength. Is this true of M/H or 8-VSB?
http://sev.prnewswire.com/computer-electronics/20090318/LA8547318032009-1.html.
It seems to me that research level, modulation, frequency, datarate,
interest, committment, political power and wealth of the parties
involved and last power in kWs would all be important and in that
order to determine if broadcasters will be still using their current
spectrum long term. Current broadcasters dedication to their residual
spectrum just doesn't seem like it is enough.
Bob Miller
On Thu, Mar 19, 2009 at 3:10 PM, Manfredi, Albert E
<albert.e.manfredi@xxxxxxxxxx> wrote:
> Bob Miller wrote:
>
>> Doesn't almost everything except 8-VSB and M/H? I was
>> responding to the antenna on each ear for mobile 8-VSB or
>> M/H reception I thought.
>
> You need an antenna for COFDM just as you do for QAM or VSB. The shape
> and size are more a function of wavelength than anything else.
>
> In the early days of 8T-VSB, it was the p*ss-poor multipath compensation
> performance of the receivers that made it seem like VSB required a
> different antenna, or more accurate aim, or whatever. Those days are
> gone, at least for the better receivers.
>
> Besides which, when John Shutt receives XM-Radio, as far as I know, ALL
> he is getting is QPSK, single frequency, from the satellite. No COFDM.
> Or do you guys have terrestrial stations in Lansing these days, John?
>
> 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:
