Troposcatter for Wireless Data

Discussion in 'Wireless & RF Design' started by Yaakov, May 6, 2019.

  1. Yaakov

    Thread Starter Well-Known Member

    Jan 27, 2019
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    Looks like the technology that brought telephone and teletype circuits to the stations of the DEWLine (Distant Early Warning Line) during the cold war will be bringing "WiFi" to the battlefield.

    They keep saying "WiFi" but I am not sure that's exactly what they mean, at least not directly. Nonetheless, this is pretty neat stuff.

    https://www.raytheon.com/capabilities/products/troposcatter
     
  2. nsaspook

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    Aug 27, 2009
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    Marketing droid speak.
     
  3. Wolframore

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    Jan 21, 2019
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    The troposphere is used to reflect communications beyond line of sight. I don't see what's so new about this except being used for WiFi. Makes sense. It gives you about 150 mile range.
     
  4. joeyd999

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    Jun 6, 2011
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    Wouldn't it be incredibly easy to jam such a network -- thereby risking the blinding of your deployed forces?
     
  5. nsaspook

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  6. joeyd999

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    I figured as much. I just assumed that the S/N must already be really low to begin with -- and it wouldn't take much broadband energy to swamp the signal.
     
  7. nsaspook

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    It's been tried on all sides. With the proper spectrum encoding of RF you can decode coherent signals below the background noise level. The trade-off is bandwidth. In the the Shannon-Hartley formula there is no stipulation that SNR" must be greater than 1.
    https://en.wikipedia.org/wiki/Direct-sequence_spread_spectrum
     
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  8. Wolframore

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    Jan 21, 2019
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    On the other hand this subject does bring up some interesting points. WiFi means gateway to the world. Obvious issues with security come to mind, does this mean Netflix when people should be concentrating on more immediate issues? Will google help our soldiers in combat? Would it pose dangers?
     
  9. joeyd999

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    I doubt it's full duplex -- required for TCP/IP.
     
  10. Wolframore

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    Unless it’s linked to a mobile forward base. The article stated dual transmission. The more I read about this. More it sounds like a system I worked on about 30 years ago. Except WiFi and darpanet has advanced much more.
     
    Last edited: May 6, 2019
  11. nsaspook

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    We ran the old AUTODIN backbone on just about everything including Tropo networks.
    https://fas.org/nuke/guide/usa/c3i/autodin.htm
    http://rogerdmoore.ca/PS/ADINC.html
     
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  12. Wolframore

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    Hey @nsaspook were you AF? It would have been nice to be able to look up datasheets while I was working back then. Would have been a good tool and a bad distraction.
     
  13. nsaspook

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    No, I was Navy but many of our facilities were on airbases like the old Homestead AFB in Florida.

    https://luxexumbra.blogspot.com/2005/06/frd-10-endangered-species.html
    Our station mainly used them comms, not intelligence gathering.
     
  14. Wolframore

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    Jan 21, 2019
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    I just read they're still using the TRC170's... i did component level... it's a good chance you linked up to one if you were using tropo. It was very high tech back in early 90's... time for more high speed low drag. Hope the new ones are as dependable.
     
    Last edited: May 7, 2019
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