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DIRECTV Satellite Discussion D-14 @99W

Discussion in 'DIRECTV General Discussion' started by Sixto, Jun 17, 2010.

  1. harsh

    harsh Beware the Attack Basset

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    The Spaceway birds don't have beams at all. They have an array of antennae that can fabricate beams.

    I'm betting the transponder bandwith is NOT variable.
     
  2. HoTat2

    HoTat2 Hall Of Fame

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    From the FCC data it doesn't;

    In non-processor or "bent pipe" mode the Spaceways form 62.5 MHz wide slots which imitate actual Ka-hi band transponders of that width which a digital transmission may use from some up to all of it.
     
  3. Diana C

    Diana C Hall Of Fame DBSTalk Club

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    I was using "bandwidth" in the digital sense (the number of bits transmitted per second) rather than the RF sense (the number of cycles per channel). While the first is dependent on the second, other factors also influence digital bandwidth, such as amplitude of the signal, the encoding method used, etc.
     
  4. Diana C

    Diana C Hall Of Fame DBSTalk Club

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    Power and fuel are the two most significant limiting factors in satellite operations. The amount fuel limits the ability to maneuver and ultimately the lifespan of the satellite. Power limits how many services can be supported. If two satellites are available, one with a set of fixed transmission characteristics that can carry 100 channels and one that has highly flexible transmission characteristics but carries only 90 channels, which one would use to fill a satellite slot (assuming they can both provide service to the desired footprint)?

    I agree that they won't be de-orbited...they are very useful as spares. But I think DirecTV would like to have more efficient satellites in their place wherever and whenever possible.
     
  5. P Smith

    P Smith Mr. FixAnything

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    Ku [MPG before, now APG kind] tpn's muxes organized by DSS mode; Ka [DVB-S2D/H.264/etc] tpns are names as DSS-3 mode. Plus, some [tp25 119W, a few tpns at 95W DLA] converted into DSS-3 mode what include DVB-S2D type.
     
  6. Diana C

    Diana C Hall Of Fame DBSTalk Club

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    My error...yes, it is DSS. But I was under the impression that DSS and DVB we're not that different, and that DirecTV was part of the original DVB standards committee, but went with their own implementation of DSS because the DVB standard wasn't ratified in time for their service launch date. I do recall that, during the Dish/DirecTV merger attempt, lots of people have said that the two systems could be made compatible quite easily and that DSS and DVB are very similar.
     
  7. P Smith

    P Smith Mr. FixAnything

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    would be a spectrogram of Ka L/R tpns [500 MHz] enough to convince you ?
     
  8. LameLefty

    LameLefty I used to be a rocket scientist

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    Reads HoTat2's entire post and THINK about it before snipping a small piece out of context.
     
  9. P Smith

    P Smith Mr. FixAnything

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    well, known both streams inside out [not 100%, but good enough] I wouldn't say so
    reading DTV patents about proprietary MPG [sort of revealing 'secret' DSS design) would show you the difference, if you will compare it to open standard DVB-S

    BTW, conversion DSS stream [131 byte DSS packets to 188 bytes DVB bytes, MPG, V/A] to DVB has been done by one guy who wrote such plugin for TSReader
     
  10. HoTat2

    HoTat2 Hall Of Fame

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    Convince me P.Smith?

    it's not really about convincing me one way or the other.

    As LL states, my post in context is quoting the data about the Spaceways' operation as filed by DIRECTV in their LOA Narrative with the FCC.

    Now if you dispute the filing as incorrect, then please blame DIRECTV and I suppose Boeing Satellite Systems too who actually built the satellites, for the error and botching this technical information big time and not seemingly accuse me of being obstinate on the issue.

    For instance, regarding SW1, the FCC Narrative illustrates and reads at one point among others on this;

    Spaceway Frequency Band-Modes Chart.jpg

    Where in the following paragraph it states here and repeatedly in other places;


    The same data in given the the LOA narrative for SW2 as well.

    So what do you expect me to say to that then? ....

    DIRECTV and BSS don't know what they are talking about? :shrug:
     
  11. P Smith

    P Smith Mr. FixAnything

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    I can't believe I'm only one here who have spectrum analyzers and do fall in awkward position when I'm going against official papers
     
  12. slice1900

    slice1900 Well-Known Member

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    So "8 contiguous 62.5 MHz channels". Keyword, 'contiguous'. As in, no guard bands between channels in that 8 x 62.5 = 500 MHz range.

    Sounds to me like it could output something that mimics what you'd get from a normal satellite using 36 MHz wide transponders separated by guard bands. In that respect, it sounds very much like what the FCC application states the 250 and 500 MHz wideband Ka transponders on D8 & D9S are capable of (though currently they're apparently only being used to output a single wideband signal to make maximum use of the bandwidth available to them)
     
  13. LameLefty

    LameLefty I used to be a rocket scientist

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    Are you being intentionally difficult or do you really not comprehend what HoTat2 posted? It seems slice1900 gets it just fine.
     
  14. Dec 1, 2013 #1054 of 3078
    HoTat2

    HoTat2 Hall Of Fame

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    Oh well ...

    According to the correspondent keeping tabs on the latest Arianespace scheduling info. at the NasaSpaceFlight.com Forum, D14's launch has been now been bumped to sometime in 2014's second quarter.

    From "Salo";

    Not really sure what "NET" means, but I assume it's synonymous to "sometime within."

    Don't know if Arianespace is behind schedule or SS/L or both, but either way looks like a February launch is off. :(

    Guess I should have anticipated as much, as I really felt things were moving along a little too briskly and setback-free for D14's launch to take place in early '14 given the nature of this business.
     
  15. Dec 2, 2013 #1055 of 3078
    HoTat2

    HoTat2 Hall Of Fame

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    OK "NET" apparently means;

    "No Earlier Than."

    So D14's launch has been bumped to " 'No earlier than' the second quarter of 2014." according to the Nasaspaceflight.com Forum's thread for the Arianespace launch schedule anyhow.
     
  16. Dec 2, 2013 #1056 of 3078
    harsh

    harsh Beware the Attack Basset

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    That's old news. See post 987.
     
  17. Dec 2, 2013 #1057 of 3078
    HoTat2

    HoTat2 Hall Of Fame

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    You're right;

    Should have kept better tabs on that site.

    Sorry for the outdated info.,

    And even more sorry I've been repeating that prospective February launch date in other threads recently.

    As I said, got to remember to keep the frequent delay/rescheduling-ridden nature of this business in mind when posting definitive dates for launches.
     
  18. Dec 2, 2013 #1058 of 3078
    HarleyD

    HarleyD Hall Of Fame

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    If every Arianne launch was not pushed back then I have to suppose that this is coming from either DirecTV or SS/L.

    However I'm not necessarily saying that there's a "problem". It could have been decided to hold off for any number of reasons. Anything from hardware to software to firmware to peopleware.

    Any word if D15 is being pushed out to 2015?
     
  19. Dec 2, 2013 #1059 of 3078
    inkahauts

    inkahauts Well-Known Member

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    Heck someone could have paid DIRECTV to swap launch dates even. In sure that kind of thing happens sometimes.
     
  20. Dec 3, 2013 #1060 of 3078
    harsh

    harsh Beware the Attack Basset

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    As the original DIRECTV 15 announcement said that DIRECTV 14 had been "accelerated" due to the impending failure of DIRECTV 10, I kinda doubt that they would have agreed to step aside unless they're supremely confident that DIRECTV 10's backup propulsion system isn't going to fail.

    http://www.spacenews.com/article/astrium-picked-build-directv-15-telecom-satellite

    As SS/L is usually quite good with their on-time deliveries (assuming there aren't a mountain of change orders), I suspect the delay must lie with either Ariane (engine sourcing?) or DIRECTV.

    DIRECTV 15 seems to be unrelated to DIRECTV 10 or DIRECTV 14 so I can't imagine why they would change its schedule unless one of the 101W satellites gets crufty or the whole Ariane schedule is sliding.
     

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