Interactive Beam Footprint Library

Discussion in 'DIRECTV Tips and Resources' started by Gary Toma, Jun 17, 2011.

  1. May 23, 2014 #81 of 194
    HoTat2

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    Well P. Smith ...

    Maybe my terminology of "available" vs "occupied" transponder bandwidth wasn't the best choice, but it still seems like we are talking about the same thing here.

    If the total "available" bandwidth of a tp. like on the Spaceways when operated in their "non-processor" or "Bent-Pipe" mode is 62.5 Mhz, but only 36 Mhz of that is used by the spectrum of a 36M0G7W type transmission relayed by it. Then about 26.5 MHz (+/- 13.25 MHz on either edge for a frequency centered signal) of the transponder's available bandwidth is not being used.

    Or is "unoccupied."

    And a signal with a 36 MHz wide spectra centered on the tp. center frequency is what should register on a spectrum analyzer.
     
  2. May 23, 2014 #82 of 194
    P Smith

    P Smith Mr. FixAnything

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    good, that was my point - no signals out of 36 MHz range on each Ka tpn, regardless its design and FCC description
     
  3. May 23, 2014 #83 of 194
    slice1900

    slice1900 Well-Known Member

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    P Smith,

    When you say you saw 36 MHz wide tpns from SW1/SW2 on a spectrum analyzer, were they using 36 MHz of a 62.5 MHz slot like HoTat2 suggests, or were they spaced the same as other Ka tpns? According to the FCC filings, the 8 62.5 MHz tpns in the Spaceway sats are contiguous, which sounds to me like they could create the same output as Directv's normal Ka sats.

    The Ka mapping has a 12 MHz guard band at the start of a 500 MHz block, then a 36 Mhz tpn, then a 4 MHz guard, then a 36 MHz tpn, and so on with another 12 MHz guard at the end of a 500 MHz block. So SW1's first 62.5 MHz tpn could have data from 12-48 MHz and 52-62.5 MHz, and the next tpn has data from 0 to 25.5 MHz and 29.5-62.5 MHz, the next from 0-3 MHz, 7-43 MHz and 47-62.5 MHz, and so on...

    But it doesn't appear to work this way, despite the FCC filing suggesting it might, because if you look at the TPN map, you see 103 has 4 Ka hi tpns from SW1 and 16 Ka hi CONUS tpns from D12. That's kind of what I'd expect if those 4 SW1 tpns (2 per polarity) were using only 36 MHz of the 62.5 MHz available. This would take up the first eight (4 per polarity) slots when using the normal Ka mapping. Otherwise, there would be room for 4 more spots from SW1 or 4 more CONUS tpns from D12.

    If the Spaceway sats are being "wasteful" with spectrum by using only 36 MHz out of 62.5 MHz, I wonder if D14 will take over SW2's spots and SW2 be relegated to spare or internal-only duty? Otherwise the six SW2 spots shown will leave only 14 Ka hi CONUS tpn slots available for D14 to use.
     
  4. May 24, 2014 #84 of 194
    P Smith

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    that's outcome of SW-1/2 co-location with D110/11/12 ... check with Gary the middle freqs of 6 tpns at SW-1/2
     
  5. May 25, 2014 #85 of 194
    HoTat2

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    According to the Schedule S documents for the Spaceways, the tp. center frequencies for "Bent Pipe" mode are simply at multiples of 62.5 MHz, with half this bandwidth or 31.25 MHz on the upper and lower band edges.

    19731.25 MHz
    19793.75 MHz
    19856.25 MHz
    19918.75 MHz
    19981.25 MHz
    20043.75 MHz
    20106.25 MHz
    20168.75 MHz

    Tps. 1 - 6 marked in red (two tps. per freq.).

    Which the above must mean that in order to use all 6 transponders aboard SW1, either tp. pair 9/10 (centered at 19890 MHz) on D12 can't be used due to overlap or tp. pair 5/6 on SW1 is offset from it's center to somewhere toward the lower edge of its assigned band.

    But I think it's more likely only tps. 1-4 on SW1 (or the first two frequencies in red) can be used as at present with tp pair 9/10 of D12 active.
     
  6. May 25, 2014 #86 of 194
    slice1900

    slice1900 Well-Known Member

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    The center frequencies for the physical transponder don't matter, it is the center frequency of the 36 MHz wide signals they're broadcasting today that matter. Do they have a 36 MHz wide signal centered on those frequencies, or are they using several of those 62.5 MHz tpns to broadcast a larger number of 36 MHz wide signals centered along the usual Ka plan? I think we'd need a spectrum analyzer's output to answer that.

    I believe the schedule S just describes the hardware and what it is capable of. If they need to file amendments as the use of that hardware changes, there should be an amended schedule S filing that describes 36 MHz wide signals somewhere. If they don't mention that anywhere, I think it is just telling us what the hardware can do, which we already know, not telling us how it is being used today.
     
  7. May 25, 2014 #87 of 194
    HoTat2

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    But what is hard to understand there is unless they are treated as physically distinct 62.5 MHz wide transponders, how can they be individually assigned to distinct spotbeams for up/and downlink?

    That is to say, how can a 36 MHz wide 36M0G7W transmission straddling one of the 62.5 MHz demarcations in your prior example be assigned to an actual spotbeam?
     
  8. May 25, 2014 #88 of 194
    slice1900

    slice1900 Well-Known Member

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    Ah yes, that is a big problem isn't it! So I guess it must be wasting spectrum and using only 36 MHz out of each 62.5 MHz transponder.

    Which is why I wondered about this, since it would seem to make sense for Directv to take SW2 off spotbeam duty once D14 is fully operational. Otherwise they'll effectively be wasting 1/6 of their Ka hi bandwidth from 99.
     
  9. May 25, 2014 #89 of 194
    P Smith

    P Smith Mr. FixAnything

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    same for 103W with SW-1 ... any tpn for DTH signal in Ka coming as 36 MHz bands
     
  10. Jun 4, 2014 #90 of 194
    Gary Toma

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    Yes, 'spear61' is on top of things...

    He is aware of the D15 Satellite filing and hopes to have our Beam Footprints ready in the next few days.
     
  11. Jul 16, 2014 #91 of 194
    HoTat2

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    Hey Gary;

    Note of correction here;

    It seems DIRECTV filed a little later on 6/12/14 for a modification to the RB-2 license so the RDBS payload antenna aboard D15 will be multi-beam to cover ConusPlus, PR, and HI., as well like with the Ka and Ku payload antennas are.

    http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/attachment_menu.hts?id_app_num=104110&acct=624514&id_form_num=15&filing_key=-265801

    So no longer just the single beam "D15 KBUS ConusPlus BSS" in the earlier D15 filing marked in red above.

    Perhaps you can notify spear61 that three new plots are needed for downlink beams of "GXT1," "2", and "3" from the link above to correct the single BSS (RDBS) beam entry for D15 here as well as for RB-2 on page 1.

    Their should be a similar filing for a modification to RB-1's antenna as well I would think. But I can't find one.

    I also think it's pretty safe now to drop Mexico and S.A. beam from both the RB-1 and 2 entries on page 1 as they appear to be only for the CONUS+, HI, and PR.
     
  12. Jul 16, 2014 #92 of 194
    Gary Toma

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    The D15 Beam Footprint post has been updated with the three new BSS Beam Footprints. How is THAT for a speedy response?? Yes - thank you once again, spear61 !

    One new feature begun with these three new BSS Beam Maps that some folks (translated: HoTat2) should really enjoy:

    While displaying the Beam Footprint, open up the GoogleEarth 'Sidebar' display. [View/Sidebar] There in the Sidebar you will see a "Space Station Call Sign" displayed. For D15, for instance, it is 2712. Clicking that call sign link will take you to the FCC filing documentation from which the Beam Footprint was derived. It is a neat way of linking the FCC documentation and the resultant Beam Footprints.

    And yes, we will be working at building in those FCC links to all our existing Beam Footprint displays.
     
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  13. Jul 19, 2014 #93 of 194
    HoTat2

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    Hey Gary;

    Many thanks for the work of you and spear61 on this so far.

    Sorry to be a PITA though, but unfortunately I don't think we're quite out of the woods yet on this. :)

    Carefully re-reading the narrative and studying the newly posted Schedule S for D15 in pdf. format, it seems that the Ka band CONUS+ has two distinct beams (surely completely overlapping of course) for the Ka A and B (or hi and lo) transponder sets respectively.

    http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/attachment_menu.hts?id_app_num=104012&acct=624514&id_form_num=12&filing_key=-265083

    See the "Schedule S Tech Report," also note the beam_ids for GXT 1 ("KBUS") and 2 ("KAUS")

    From the Narrative P. 7

    DIRECTV-15 Beams.png

    So correct me if I'm reading this wrong, but it appears the D15's Ka downlink beam designations are;

    KAU - "Ka A-Band U.S.?"

    KBU - "Ka B-Band U.S.?"

    KAHI - "Ka Band Hawaii?" (i.e. A single beam for both Ka A and B bands)

    KAPR - "Ka Band Puerto Rico?" (Again, means a single beam for both Ka A and B bands)
     
  14. Jul 24, 2014 #94 of 194
    Gary Toma

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    A good reference from spear61:

    You will see all kinds of different descriptions of the new frequencies in the filings and forum posts. A real mix of descriptions for the same bands and can get confusing.

    When in doubt, use the FCC technical definitions.

    For reference, the definitions as specified in Title 47 of the US Code are:



    12/14 GHz bands. The 11.7-12.2 GHz Fixed-Satellite Service (FSS) space-to-Earth band and the 14.0-14.5 GHz Fixed-Satellite Service Earth-to-space band.

    17/24 GHz Broadcasting-Satellite Service (17/24 GHz BSS). A radiocommunication service involving transmission from one or more feeder-link earth stations to other earth stations via geostationary satellites, in the 17.3-17.7 GHz (space-to-Earth) (domestic allocation), 17.3-17.8 GHz (space-to-Earth) (international allocation) and 24.75-25.25 GHz (Earth-to-space) bands. For purposes of the application processing provisions of this part, the 17/24 GHz BSS is a GSO-like service. Unless specifically stated otherwise, 17/24 GHz BSS systems are subject to the rules in this part applicable to FSS.

    Direct Broadcast Satellite (DBS) Service. A radiocommunication service in which signals transmitted or retransmitted by Broadcasting-Satellite Service space stations in the 12.2-12.7 GHz band are intended for direct reception by subscribers or the general public. For the purposes of this definition, the term direct reception includes individual reception and community reception.
     
  15. Aug 30, 2014 #95 of 194
    Gary Toma

    Gary Toma UNIX

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    For Sanity:


    The DIRECTV D15 KA payload is Space Station 2930.

    The DIRECTV D15 BSS 17/24 payload is Space Station 2712

    The DIRECTC KU payload will be one more Space Station license application, when and if they choose to use it.

    There can be multiple 'Space Stations' on one physical satellite.
     
  16. Sep 19, 2014 #96 of 194
    slice1900

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    I have been curious for a while about the various Directv facilities and what they do, to learn more about how the locals work and how spot beams are uplinked. I had to sit in on a long useless con call earlier today, so I used the time to dig into the FCC filings. I was hoping for a bit more specificity on which sites uplink to 101, but it does provide a good map of what sites are out there and what they can do. This covers every facility Directv is currently licensed to uplink from in the US, so I guess in a way it is the reverse of the footprint library :)

    NAME LOCATION Ku uplink Ka uplink RDBS uplink

    CANOGA PARK Los Angeles, CA 99/101/103[*]
    CRBC Castle Rock, CO 101/110/119 99/101/103 99/103
    CRDUF Englewood, CO 101/110/119 99/101/103
    ECUF Winchester, VA 101/110/119
    LABC Los Angeles, CA 101/110/119 99/101/103 [!]
    LADUF Long Beach, CA 101/110 99/101/103
    LITTLETON Littleton, CO 99/101/103
    MWDF Big Lake, MN 99/101/103
    MWUF Oakdale, MN 101/110/119 99/101/103
    NEDF Littleton, NH 99/101/103
    NEUF New Hampton, NH 99/101/103
    NWDF Ellensburg, WA 99/101/103
    NWUF Moxee, WA 99/101/103 99/103
    PAS ATLANTA Atlanta, GA 101/110/119
    SWDF Benson, AZ 99/101/103
    SWUF Tucson, AZ 99/101/103

    [*] Ka hi only
    [!] Yes, LABC is not currently licensed for RDBS!

    Based on this it is a little easier to explain/understand how spot beams work, since 119 makes for a nice simple example. There are five sites licensed to uplink to 119. [Edit: the site in Atlanta was originally missed, so there is an additional site not included when I wrote this] The two in Colorado are only 20 miles apart, so can probably be considered as one for the purpose of uplinking unless the satellite can aim its receiving antenna a lot more precisely than I would think!

    ECUF and MWUF collect the locals uplinked to 119 from the eastern US and midwest, respectively, and LABC and/or CRBF collect the locals out west. One of those two main broadcast centers uplinks the 7 CONUS transponders for 119, the other would uplink the western US spot beams, and the ECUF and MWUF would uplink their own locals. The allocated uplink frequencies for all 11 transponders Directv is licensed for would be used to do this. Thus, the three sites could uplink a maximum of 33 spot beams; there are in fact 29 spot beams broadcast from 119.

    While it would be impossible to ever determine what is uplinked from where for the spots from 99 and 103 based on this information, it seems clear that there's absolutely no role for 101's Ka capability in all this. HoTat2 recently posted details on the uplink/downlink for Ka from 101, and it makes even less sense now that I've dug up the complete list of Directv sites.

    D8 has "receive spotbeams from Seattle, Atlanta and NY". Directv has no licensed Ka uplink facility in any of those places! It also can receive a spot beam from CRBC as an alternate path to LABC, where it has a downlink. It has a second downlink to Kansas City, but Directv has nothing there unless it is receive-only and doesn't need to be licensed. D9 can receive a spot beam from LABC and Boise, ID (nope, Directv has nothing there either) and can downlink to MWUF or SWUF. So essentially all 101 can do is provide an alternate path from CRBC to LABC, and LABC to MWUF and SWUF.

    Edit: Added PAS ATLANTA which was missed previously, which adds an additional site able to uplink to 119
     
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  17. Sep 20, 2014 #97 of 194
    HoTat2

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    Nice post;

    And thanks for taking the time to dig all this up.

    Just a couple of points, DIRECTV seems to have a Ku uplink facility at PAS Atlanta which is now an Intelsat site ---

    Two Ku 8.1m Dishes located at the PAS (PanAmSat) ATLANTA uplink site, which is now owned by Intelsat
    2857 Fork Creek Church Rd., Dekalb Co., Ellenwood, GA.
    33°39'50.00" N. LAT. 84°16'24.00" W. LONG.

    And DIRECTV has applied for an RDBS license at their NEUF to pair with their one at the NWUF. Changing plans for it at their SWUF.
     
  18. Sep 20, 2014 #98 of 194
    slice1900

    slice1900 Well-Known Member

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    I was doing a search on applicant/licensee name "directv", service "SES", application type "LIC" to keep the numbers manageable. For some reason that Atlanta site doesn't have a license application listed, so it was missed. Maybe a clerical error on the FCC's part?

    Is there any way to know if that site, or the one in Brooklyn, is still in use by Directv? Do they have to file anything if they shut it down, or will the license remain until it expires and nothing is filed to renew it?

    As far as RDBS, I was only grabbing active licenses. I know the situation will change over time as RDBS licenses are added, but they've got a pretty good collection of sites. Other than perhaps shutting down the Ku only locations like Brooklyn, Atlanta, and ECUF when they dump MPEG2 in a few years, there shouldn't think there would be many changes beyond additional RDBS licenses.
     
  19. Sep 20, 2014 #99 of 194
    HoTat2

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    Yes, I realize that and don't know why I even bought that point up.

    My apologies on that ....
     
  20. slice1900

    slice1900 Well-Known Member

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    OK, thanks for the updates. I removed Brooklyn from the list. I left Atlanta in for now. It doesn't make sense that Directv would file to transfer control of anything to AT&T before the sale is finalized, and only file to transfer this one station. Very odd.

    Anyway, for the moment it is still operated by Directv, and may uplink SD locals to 101 or 119 from DMAs down south so I'll leave it in.
     

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