Page 5 of 5 FirstFirst ... 345
Results 41 to 45 of 45

Thread: Interactive Beam Footprint Library

  1. #41
    Senior Member
    Join Date
    Oct 2016
    Posts
    334
    Or after some more thought is it possible the Schedule S is wrong on the frequency assignments given to the Ka band uplink beams?

    As perhaps they really should be ...

    3A1L/3A1R = 29.5-30 GHz
    3A2L/3A2R = 29.5-30 GHz

    3B1L/3B1R = 28.35-28.6, 29.25-29.29 GHz
    3B2L/3B2R = 28.35-28.6, 29.25-29.29 GHz

    Which would make a lot more sense and be consistent with the "A"/"B" lettering and center frequencies of the tp. "Channel IDs" listed later on in the Sch. S document.
    Last edited by HoTat2; 03-10-2019 at 07:37 AM.

  2. #42
    Super Moderator Tom Speer's Avatar
    Join Date
    Jul 2015
    Location
    Adirondack Mtns, NY and Eastern NC
    Posts
    1,308
    Quote Originally Posted by HoTat2 View Post
    Yes, I get all this Tom ...

    And after some more study I don't believe it's a mistake any longer. But an intentional mislabling of uplink receive beams for Castle Rock "3A2L" and "3A2R" which according to the Schedule S covers 29.25-29.29 GHz that is actually part of the Ka B band.

    But then again, they obviously couldn't label the beams as "3B2L" and 3B2R" as those designations are used to refer to the receive beams for CR on 28.35-28.6 GHz.
    That doesn't compute. Beam contours KRCL and KRCB are clearly labelled as transmit beams in the GIMS database, and their beam patterns are similar to all T16 CONUS transmit beams. All the Castle Rock uplink receive beam footprints are very narrowly focused on Castle Rock.

    I think we have been reading too much into the beam descriptions in schedule S . It is not the controlling document for their application to launch and operate at 103. What they are asking the FCC to grant is described in the Narrative of SAT-RPL-20180913-00071. That includes uplinks for all currently licensed Ka bands, both A and B, (except 29.29-29.5 GHz, which are the B band uplinks to the spot beams on D12). It distinctly applies for authorization for all of those, identically, from both CRBC and LABC.

    The Schedule S and beam contours are supplemental data, and I now think, describe the tests and calculations they have performed for representative samples of the satellite capabilities.

    The narrative description does not indicate that the Ka Band antennas and receivers are separated between A and B bands, and calculated beam footprints also are nearly identical. Any deviation could be attributed to frequency differences. The calculation of the KRCL and KRCR beam contours, may have been a “what if?” calculation, maybe considering using the reverse band antennas to substitute for the Ku band antenna following damage.
    Last edited by Tom Speer; 03-08-2019 at 03:09 PM.
    Tom Speer, N2HF, the curious otter. Part of the DataDigesters team.

  3. #43
    Senior Member
    Join Date
    Oct 2016
    Posts
    334
    Oh sure, I agree its a relatively minor point in the overall FCC documentation.

    But was just pointing out how the frequency band assignments DIRECTV gave in the Sch. S for the Ka band uplink for the LABC and CR are confusing, and in my opinion, mistaken.

    As they have the LABC uplink between 29.5-30 GHz for the A band which is correct. But list only between 28.35-28.6 GHz for the B band, and mentions no access to 29.25-29.29 GHz.

    Whereas the uplink from CR only list 29.25-29.29 GHz for the A band access (when that's actually part of the B band). And shows no access to the real A band between 29.5-30 GHz like the LABC has.

    Simarily CR's B band access shows as only between 28.35-28.6 GHz as the LABC does.

  4. #44
    Super Moderator Gary Toma's Avatar
    Join Date
    Jul 2015
    Location
    San Diego
    Posts
    441
    Quote Originally Posted by Tom Speer View Post

    ... Our initial posting has omitted beam T16_3B2R_CR, due to my error in extracting the GXT files from the GIMS database. Gary will add that when he gets a chance, but it is pretty close to 3B2L.
    Beam T16_3B2R_CR has been added to the library. Again: Thank You, Thank You, Tom Speer.

  5. #45
    Senior Member
    Join Date
    Oct 2016
    Posts
    334
    And the following was mistakenly posted in the TPN Map thread a few days ago, but should have been here related to this topic ...

    Or after some more thought is it possible the Schedule S is wrong on the frequency assignments given to the Ka band uplink beams?

    As perhaps they really should be ...

    3A1L/3A1R = 29.5-30 GHz
    3A2L/3A2R = 29.5-30 GHz

    3B1L/3B1R = 28.35-28.6, 29.25-29.29 GHz
    3B2L/3B2R = 28.35-28.6, 29.25-29.29 GHz

    Which would make a lot more sense and be consistent with the "A"/"B" lettering and center frequencies of the tp. "Channel IDs" listed later on in the Sch. S document.
    .

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •