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DirecTV National HD Listing/Maps Discussion Thread (Technical - Not Anticipation)

Discussion in 'DIRECTV Programming' started by Sixto, May 29, 2012.

  1. Jul 7, 2012 #321 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    It may not be worth picking at but 8-03-10 doesn't seem that long ago, and the pdf is dated October 2010 .
     
  2. Jul 7, 2012 #322 of 653
    Sixto

    Sixto Well-Known Member

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    What happened on 8-03-10?
     
  3. Jul 7, 2012 #323 of 653
    georule

    georule Hall Of Fame

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    We certainly have plenty of evidence that D*'s technical roadmap extends out several years at any given point.

    They had a new bird to play with at the end of 2009. They knew when they had D14 scheduled. I don't see it as all that unlikely that they could have identified this new technology in the 2009 period as something they'd want to implement in 2012, post D12 filling up, as a bw-increase bridge to D14. Why rush it when you've got D12? Let it mature, get rev'ed, etc.

    And no doubt the engineers would want to poke at it for a considerable length of time in the lab on the road to that, including competitve analysis of vendor implementations.
     
  4. Jul 7, 2012 #324 of 653
    inkahauts

    inkahauts Well-Known Member

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    I going to say I think it may be a mix of 1, 3, and 4. If you take all one things into consideration, and the fact that the article says each channel could be 20% more efficient, I think if they had all that going for them on five channel that might open up enough space for a sixth channel.

    It also could be the reason we are seeing this happen slowly is because they are upgrading encoders and spreading out the money they are spending on that process slowly over time.

    Plus something someone once said has me thinking the costs of these upgrades isn't soley being taken on by DIRECTV, but maybe that is also part of the process of getting new contracts for new channels.
     
  5. Jul 8, 2012 #325 of 653
    georule

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    Well, I don't own any Ericsson stock, so I don't have a problem with that observation. :D

    Sometimes, even in a competitive landscape, one vendor or another gets a engineering leap on the field for a year or two. It certainly happens. I haven't heard anything that leads me to believe that D* has some kind of fetish on the matter of vendors that would override their natural self-interest as a tech company.

    Because at its heart, that's what D* is. Yeah, there's all that marketing overlay, but they know they are selling state-of-the-art tech at the core, even once the marketing folks get done popularizing why the masses should care.
     
  6. Jul 8, 2012 #326 of 653
    harsh

    harsh Beware the Attack Basset

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    Fanboyism aside, how is it that DIRECTV is only managing to wring 5-6 channels out of 36MHz of satellite bandwidth?

    The answer (nor understanding thereof) has nothing to do with what provider anyone subscribes (or doesn't subscribe) to so there's really no need to visit there.

    For reference, Blu-ray is around 24MHz.
     
  7. Jul 8, 2012 #327 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    This makes no sense.
    As for 5-6 HD channels per 36 MHz BW, it has everything to do with the modulation type they're using.
    "For example" if it was the same as ATSC, then it would manage easily 6-7, 19.2 Mb/s channels.
     
  8. Jul 8, 2012 #328 of 653
    Sixto

    Sixto Well-Known Member

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    The key isn't as much the MHz as the data bandwidth per transponder, which is about 38Mbps as best we can tell. The translation form MHz to Mbps depends on the engineers desire for quality considering weather and the technology available, along with the type of transponder/license (Ka).
     
  9. Jul 8, 2012 #329 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Each type of modulation has its pros & cons and another example is my U-who that has 64 Mb/s while using 7.5 MHz BW.
     
  10. Jul 8, 2012 #330 of 653
    Sixto

    Sixto Well-Known Member

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    Exactly, and in this specific D1x case they're currently at 38Mbps as best we've calculated.
     
  11. Jul 8, 2012 #331 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Someone with a Spectrum Analyzer would be able to measure the BW.
     
  12. Jul 8, 2012 #332 of 653
    Sixto

    Sixto Well-Known Member

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    Yep, I haven't myself but others have.
     
  13. Jul 8, 2012 #333 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    A couple of differences between ATSC and the SAT modulation is my TV needs more than 13 dB SNR to stay locked without errors, while the SAT works down to about 8 dB CNR.
     
  14. Jul 8, 2012 #334 of 653
    georule

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    Hardware vendors have been known to gild the lily, certainly. . . but if you take the presentation seriously (and the presentation was not produced by DirecTV), 6Mbps x 6 = 36Mbps. Pg 27/28. As Sixto notes above, best calculations have the newest D* birds at 38Mbps per TP. Those calculations took place *before* the latest move to 6 HD per TP, so cannot be accused of trying to reach a pre-determined result to fit a theory.

    So, you can bag on D* all you like, and cry "fanboy!" to your heart's content, but it isn't just D* saying this is possible with the latest/greatest encoders; it is also Ericsson.

    Therefore, before you start doing the fanboy j'accuse, you better either disprove 38Mbps, or go after Ericsson credibly as liars.
     
  15. Jul 9, 2012 #335 of 653
    cypherx

    cypherx Hall Of Fame

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    Wow what modulation rate works down to 13 dB SNR? 256QAM has a MINIMUM of 32 dB and that's 38.8mbps in a 6 MHz wide channel. Helps when cable is a closed system though. I've had SNR's as high as 40 before on DOCSIS channels, though they hover around 37, 38.
     
  16. Jul 9, 2012 #336 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    OTA needs to work with weaker signals, than a CATV system.
    My OTA can be as high as 28-30 dB SNR.

    My U-Who runs at 28-29 dB "noise margin", but their minimum is around 12 dB, and maybe even 9 dB.
     
  17. doctor j

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  18. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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  19. P Smith

    P Smith Mr. FixAnything

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  20. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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