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Can We Get Global Broadband From Low-Earth Orbit Satellites? (blogspot.com)

"The internet is unavailable to and/or unaffordable by about 50% of the world population," writes Larry Press (formerly of IBM), who's now an information systems professor at California State University. But he's also long-time Slashdot reader lpress, and reports on new efforts to bring cheap high-speed internet to the entire world. SpaceX, Boeing, OneWeb, Telesat, and Leosat are investing in very large projects to deliver global, high-speed Internet service [using low-earth orbit satellites]. This could be a significant option for developing nations, rural areas of developed nations, long-haul links, Internet of things, and more by the mid-2020s.
Parts of Alaska could see internet-via-satellite as soon as 2020, according to Larry's article, which adds that the technology could even be used to bring high-speed internet access to ships at sea.

15 of 134 comments (clear)

  1. Why not? by nospam007 · · Score: 5, Informative

    We already get internet by satellite from a dozen companies.

    Here are the top ten.
    http://www.toptenreviews.com/s...

    1. Re: Why not? by K.+S.+Kyosuke · · Score: 2

      With LEO satellites, there's significant number of advantages, though. The signal is much stronger, obeying the inverse square law. Compared to GEO, it's several hundred times stronger. Spatial resolution of targets on the ground is much better, too, giving more bandwidth just from improved spatial separation. This compounds with the stronger signal, obviously. And the latency is way lower, too. None of it still beats landlines in cities, but outside of cities, chances are that satellites would perfectly serve all the locations that ISP refuse to connect properly. (Even in cities, the situation could improve this way *a lot* for people stuck in ISP-shitty spots.)

      --
      Ezekiel 23:20
    2. Re: Why not? by Junta · · Score: 2

      Depends on how low earth we are talking, and how many.

      It seems that a minimum practical orbit for satellites would be 300 km. At that altitude, assuming you wanted to minimize the count of satellites then you'll be having to reach a satellite on the horizon which would mean 2,000 km at that altitude, for a worst case round trip of about 130 ms, and a best case of about 2 ms, depending on the best positioned visible satellite. Adding more satellites can result in achieving some cap on worst case.

      It could be possible to have acceptable latency, but the cost may be too great (the lower the orbit, the more fuel needed to maintain orbit before it falls).

      Of course, another thing to ponder would be solar powered UAVs (https://en.wikipedia.org/wiki/Qinetiq_Zephyr). A lot more would be needed and would have to rotate in and out of service, but being reusable could be a huge plus (and the latency goes to worst case 3 ms round trip). Also could be more specifically deployed (a satellite orbit will necessarily provide coverage over it's orbit, which may include a lot of empty surface area).

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    3. Re: Why not? by dszd0g · · Score: 3, Informative

      Not even if it went around the world across the Atlantic ocean, Europe, Asian, and the Pacific ocean rather than directly unless you made a trip out of the way (for example, from Europe to northern African along the way).

      Current satellite Internet uses geosynchronous orbits of 22,000 miles away. The equatorial circumference of the earth is about 24,900 miles.

      The circumference at the Chicago and New York latitudes of 41.9 and 40.7 respectively is less. The radius of the earth is about 3,959 miles.
      The circumference at a latitude of 41.3 is approximately:
      =2*pi*r
      = 18,687 mi
      Or you can also do:
      (equatorial circumference) * cos (latitude in radians)
      24,900 miles * cos((41.3/180)*pi)
      = 18,706 mile
      Which is slightly different because the earth isn't exactly a circle.

      https://en.wikipedia.org/wiki/...
      http://mathforum.org/library/d...

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  2. Movement by JBMcB · · Score: 4, Insightful

    Getting a two-way connection from a moving satellite is a nightmare. You get all kinds of frequency-shift, Doppler, atmospheric, and localized multi-path problems. You'll need a big chunk of spectrum for all the error correction and sync signals required. You'll either need a tracking dish, which will be expensive, or a phase-array, which is cheaper to build but will require a more complicated and expensive front-end.

    It may work for niche cases for low-bandwidth applications in remote areas. I'm guessing the uplink hardware will be so expensive that you'll have micro-ISPs serving small areas.

    --
    My Other Computer Is A Data General Nova III.
    1. Re:Movement by K.+S.+Kyosuke · · Score: 2

      It's tricky, surely, but with modern solid-state systems, I would be more careful about dismissing the possibility. I'm pretty sure your ordinary cell phone would seem of possibly alien origin to RF designers from thirty years ago, too.

      --
      Ezekiel 23:20
  3. Latency is the Crucial factor by mysidia · · Score: 3, Informative

    LEO Satellites at 1200 miles up will have a minimum Earth-Ground latency of 24 milliseconds and Earth-Ground-Earth Latency of 48 milliseconds because of the speed of light ---- this is a major latency issue unless there are MANY infrastructure Earth stations at major colocation facilities AND the traffic can be efficiently routed, so we're not landing traffic in a NEW YORK internet exchange that then needs to be routed to SAN FRANCISCO, or Atlanta, and thus appending another 50 milliseconds of ground latency after the satellite hop, for example.

  4. Re:Latency by techno-vampire · · Score: 2

    I used to do tech support for an ISP, and I had to deal with issues like this every day. Just to get a response from your ISP's router, your packet has to go up to orbit and back. Twice. That can add quite a bit to your response time. However, given the choice between that and no connection at all, it's something that can be lived with.

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    Good, inexpensive web hosting
  5. Re: Even terrestrial wireless... by mysidia · · Score: 2

    Well, at least the ground-based 2005 wireless systems we have can survive common X-Class Solar flares and normal-magnitude CMEs we occassionally see without risk of equipment being permanently destroyed .

  6. Re:Latency by Junta · · Score: 2

    Of course, right overhead is a rare optimistic case. Worst case would be satellite on horizon, there your round trip would be at least 130 ms (assuming at least 300 km orbit). By satellite standards pretty good and serviceable for most non-gaming situations.

    Adding solar UAVs to the mix may confer a lot of the benefits of geosyncronous satellites, though would require a ton more of them.

    --
    XML is like violence. If it doesn't solve the problem, use more.
  7. Re:Latency by Junta · · Score: 2

    Of course *all* satellite communication is at the speed of light, whether optical or not.

    --
    XML is like violence. If it doesn't solve the problem, use more.
  8. SpaceX's solution by EnsilZah · · Score: 3, Interesting

    Being somewhat familiar with SpaceX's plans here are a few advantages of their approach, I guess compared to traditional satellite providers:

    They're planning to deploy thousands of cheap, small, short-lived satellites in LEO, which means:
    -They get the advantages of cheaper production due to economies of scale, orders of magnitude better than something like GPS or Iridium.
    -So many units means they can just over-provision, use less hardened, cheaper components, and just replace units as they fail.
    -Being in LEO means they have a shorter lifespan due to atmospheric drag, so they stay up for maybe 5 years, drop into the atmosphere and are replaced by newer, better hardware.
    -I did a back of the envelope calculation once and I think I came up with something like 1/3 the latency of fiber when going halfway around the earth, due speed of light in glass vs air/vacuum, and the various geographical features cables need to contend with.
    -One of the reasons I remember being mentioned for SpaceX getting into building their own satellites when their rocket reuse program was just getting off the ground is they'll eventually end up with a supply of rockets that's larger than the entire launch market is going to need, at least in the short term, so this is a way for them to be their own customer and amortize the cost of the rocket by reflying it 10 times with cargo they can afford to lose.

  9. I hope not. by plopez · · Score: 2

    Places free of the pollution of the internet are getting rarer by the day. Digital quiet is a disappearing resource. What about VLA and people who prefer to live and vacation in places without connections?

    --
    putting the 'B' in LGBTQ+
    1. Re:I hope not. by sa.naidu.1958 · · Score: 2

      Just turn your device off.

  10. What ROI? by manu0601 · · Score: 2

    I am surprised to see corporations investing on poor countries. What kind of return on investment do they expect here?