Oh, come on TV is a business. Aside from engineering, do you think there is a economic difference between a service that charges per minute (for individual connections) and one that doesn't and provides the same service for one and all? And, PLEASE don't go into the sfn b.s. If TV was delivered by SFNs, we will be paying the same per-minute rates for tv that we do for cell service. Or more. Also, I think you need a more generous budget for portable/mobile operations versus fixed, and well into the future, there will be no more than 1% of viewers tuned into mobile TV. EVEN WITH WIRELESS LINK BUDGETS. After all, economics is just as important as engineering in fashioning a real service. (Except in 'licence fee' countries, where the fee works against the interest of the viewers.) John Willkie -----Mensaje original----- De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En nombre de Eory Frank-p22212 Enviado el: Thursday, July 05, 2007 4:32 PM Para: opendtv@xxxxxxxxxxxxx Asunto: [opendtv] Re: DTT tuner design Dale Kelly wrote: >I fail to see the purpose for studying cell phone or DBS assumptions and >link budgets are already understood - made more difficult/dynamic for 8VSB >multipath demodulation. We all know well the FCC assumptions (planning >factor) for obtaining desired DTV coverage and the propagation of television >signals has been extensively studied and understood. Unfortunately the CE >folks failed to honor these assumptions and under pressure, adopted A74, >which is also deficient in certain critical areas. However, my BS remark was >as much aimed at Frank's very weak analogy as anything else.... My point about cell phone & DBS link budgets is that they are designed from the get-go to have margin -- a healthy, positive number of dB's under not just ideal conditions, or even average conditions, but even under poor conditions. Why? Because it's a business, and if there are too many dropouts or too many customers who can't get reception where & when they need it, the revenues will stop and the business will fail. It isn't perfect (especially cellular), but it's pretty darn robust for most customers most of the time. Apparently DTT isn't really a business -- or to be more correct, it doesn't require a robust wireless link in order to maintain its customer base and revenue stream. The FCC's link budget for DTT is extremely optimistic, especially if one relaxes the 30 foot mast antenna 'requirement.' It virtually guarantees that many viewers in each DMA will have spotty or no DTT service under conditions where they at least had some degree of NTSC service. Notice I didn't say anything about modulation. Because it doesn't really matter. Optimistic link budgeting is disasterous in wireless digital transmission, regardless of modulation. Just as optimistic financial budgeting is disasterous, whether your accounts are in dollars or Euros. I'm not sure why you thought my founding fathers' newspaper delivery analogy was such BS. Beautiful, wonderfully presented "content," but a less-than-robust delivery system that fails to ensure that the "content" reaches the full audience. I think the founding fathers would "get" my fancy newspaper/weak horse delivery analogy as it relates to our HDTV DTT predicament. Funny that you think I represent the CE position. I'm a chip designer who works for a chip manufacturer. We're the guys who get squeezed by the CE companies for every nickel of cost. We're the ones expected to make the R&D investment in all the wonderful new algorithms & architectures required to solve a technical problem that shouldn't exist -- one that was essentially created by politicians. And one which ultimately has no solution -- just varying degrees of compromise that will never satisfy all the people all the time. Oh by the way, I can't really blame the CE guys for squeezing chip vendors for every nickel. They get squeezed too. Everyone in the chain does, because at the end of the chain is the consumer -- who always wants more for less. I'm a consumer too and I want more for less, so I'm just as much a part of the problem as anyone. "We have met the enemy, and they is us." -- Frank ---------------------------------------------------------------------- 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.