|Originally posted by cwood:
At this point, few of us on this forum, much less the public at large, care! 8VSB is what we have in the US. It will invariably get better soon, in terms of receiver technology. Three years from now the technical arguments will be largely moot...except for those of course who have datacasting as an agenda.
My experience with 8VSB, under very difficult reception conditions in the mountains of Utah, has been excellent...far better than analog over-the-air reception.
And because of the lesser efficiencies of COFDM relative to 8VSB, broadcasters would pay a substantially higher electrical bill each month simply to achieve equivalent coverage area.
Finally, the entire concept of high power terrestrial television broadcasting, whether 8VSB or COFDM, is largely obsolete. What we need is a combination of satellites with spot beams to replace big stick transmitters, coupled with must-carry cable laws, with any reception gaps filled in by low power digital repeaters.
First this thread is about HDTV International so the "public" is interested at least the "public" that is international. Many international types do read this Forum but have been intimidated by inflamatory rhetoric here about other standards such as COFDM DVB-T and do not post. Most countries have chosen COFDM DVB-T. This is an Internet Forum which implies International and it does have an International clock. I don't see anywhere that it is a parochial endeavor or that the concept of HDTV is limited to the US.
I am happy that 8-VSB works for you and that you get better reception than with analog in Utah. That the US has decided to stick with 8-VSB works for me businesswise. I hope the US sticks with it for at least three years. This will give us (my company) a head start.
As far as those "who have datacasting as an agenda" that would emphatically include all US broadcasters who to a network are quoted as beleiving that datacasting is what will pay for the DTV transition. And of course datacasting is what you do when you broadcast digitally anyway.
You also agree with me that by the time 8-VSB gets better the question will be moot. OTA broadcasting will be dead and irrelevant as you say.
OTA broadcasting in the US will be dead but not in the rest of the world. With COFDM and using SFN's (Single Frequency Networks) and low power (on channel) repeaters (as you mention)OTA broadcasting will have a rebirth that will put the business plans of cable and satellite at risk.
One more thing about the technology question being moot. The simple fact is that that is already true in most of the world. Other than the few countries tied politically to the US such as Canada, Mexico and S. Korea, in most other countries the question is already moot. They have made a choice and there is no second guesing going on. They chose DVB-T COFDM.
As to the "lesser efficiencies of COFDM". Would you care to come to Toronto and demonstrate this? I have an open invitation to anyone to show me any spot that COFDM can not be received in and 8-VSB can. NO TAKERS SO FAR!
It seems that whenever any 8-VSB type wants to demonstrate their superior reception they will only do it under non-disclosure or behind curtains.
The simple fact is that in Toronto if you or anyone care to come we will demonstrate that at any spot you chose under the same power if 8-VSB is receivable COFDM will also be receivable. Further we will show you inumerable sites where 8-VSB is not receivable. We will then drive around the spots where 8-VSB is NOT RECEIVABLE demonstating that COFDM is receivable mobile at the same location. We will do this with HDTV content.
One last point. With current COFDM receivers and the same power level COFDM will equal 8-VSB in the far feild while blowing it away anywhere else. With SFNs that COFDM is made to work with and 8-VSB is not, the COFDM power requirement drops by up to 90%. With the new diversity receiver chips which take unique advantage of the COFDM architecture, the power advantage even with the big stick transmitter concept goes emphatically to COFDM. That is COFDM will either reach futher than 8-VSB or the same as 8-VSB but with less power. The advantage you talk about is from one laboratory report that showed a 2 to 4 dB advantage for 8-VSB in the far feild. It has never been demonstrated in the real world. With diversity receiver chips that laboratory advantage goes from plus 2 to 4 dB to minus at least 2 to 4 dB and in the real world it will be measurable as a plus for COFDM.
We hope to demonstrate diversity receivers in Toronto soon.
Most of the world is going COFDM. The economies of scale strongly favor COFDM. Already in Australia the HDTV receivers are half the price of receivers in the US. And COFDM has more labs around the world trying to improve it also.
One more thing. Let us assume that you are right that COFDM needed more power to get the same coverage that 8-VSB has. If both were allowed every broadcaster would immediately switch to COFDM and be all too glad to pay the higher power bill. IMHO and the opinion of all the broadcasters I have talked to about it.