Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Space Businesses The Internet

Can We Get Global Broadband From Low-Earth Orbit Satellites? (blogspot.com) 134

Posted by EditorDavid from the we-could-call-it-Skynet dept.
"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.
This discussion has been archived. No new comments can be posted.

Can We Get Global Broadband From Low-Earth Orbit Satellites? More

Can We Get Global Broadband From Low-Earth Orbit Satellites?

Comments Filter:

  • Why not? (Score:5, Informative)

    by nospam007 ( 722110 ) * on Saturday December 23, 2017 @03:59PM (#55797327)

    We already get internet by satellite from a dozen companies.

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

    • Re: Why not? (Score:1)

      by Anonymous Coward

      Yeah well, with 600 ms minimum ping a lot of the internet just ignores you and quietly drops the connection.
      Streaming video will not play nice with you until after midnight.
      Games are straight up out of the question unless you mean poker or chess.

      • 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 se

        • Movement (Score:5, Insightful)

          by JBMcB ( 73720 ) on Saturday December 23, 2017 @04:45PM (#55797529)

          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.

          • 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.

          • I don't think the satellite contact is a difficult as you think. Distances will be short -- a few hundred km at most. Ground stations may need to use a bit more power than we're used to -- 10s of watts maybe and bandwidth may not be great if frequency division is used to divide users users. (How would we/they synchronize time division multiplexing?) Directional antennae probably aren't required -- which is a good thing because satellite passes will probably be one or two hundred seconds. The satellite

          • Re: (Score:2)

            by mikael ( 484 )

            It never worked out for the Iridium satellite network:
            https://en.wikipedia.org/wiki/... [wikipedia.org]

            What if every cell-phone tower had it's own satellite dish?

            • It worked fine for iridium, in every technical sense. They simply failed to turn a profit because of rapidly expanding cell tower coverage making their market much smaller than they'd counted on. That's always a risk when you're launching a fleet of satellites that take a few years to get up there. Thanks to SpaceX they seem to be launching a lot faster with the new LEO constellations, though.

          • Getting a two-way connection from a moving satellite

            You may want to look up the definition of geosynchronous...

          • Getting a two-way connection from a moving satellite is a nightmare.

            It may be a nightmare, but it's a solved nightmare. The last time I was looking at ground stations for such systems at work (where you live on site for months, because it takes days to get to the site), you could get change out of $10000 for hardware costs, or change from $15000 if you wanted solidly-built equipment. It's not cheap, but it's not horrendous either. It's not $20/month.

            You'll either need a tracking dish, which will be expens

      • Re: (Score:3)

        by Junta ( 36770 )

        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 b

        • While they do have solar powered UAVs that can store sufficient energy to saw aloft 24/7, the energy requirements of the radio equipment would cause problems. If it was easy to do they would have done it already. First flights of a UAV flying 24/7 were done a while ago and since then there has been very little to report. But if someone knows of something I missed, please fill me in..
          • UAV radio retransmitters powered by a microwave beam from the ground station should work. No batteries or solar pannels required on the plane, and the broadcast power beam would double as your uplink. Getting more than 99.9% uptime would be difficult given all the moving parts but most of your market would accept that for the massive cost savings over sat.

    • Those providers are all in geosynchronous orbit at 23,000 miles. Low Earth orbit satellites would be less than 500 miles which would cut the latency to around 2% of the geosynchronous latency. Quite an improvement I would say.

    • Sattellite internet is slow and expensive. People who don't have internet now probably can't afford this, people who do have internet gain nothing from this. People with money and living/working in remote locations are a very small market who mostly already have several options. I don't see arctic oil drill camps as being a large enough market to pay for the launch costs.

      • Re: (Score:2)

        by jon3k ( 691256 )

        people who do have internet gain nothing from this

        The, I don't know, 90% of the country that only has a single cable provider as their only ISP certainly have a lot to gain. Just like they do from the deployment of fixed 5G broadband. It's called competition.

      • I don't see arctic oil drill camps as being a large enough market to pay for the launch costs.

        How about farmers? For as long as people continue eating, farms will continue to exist, and it will continue to make sense to put them outside of cities. Even in a highly developed place like California, there are millions of people who have no non-satellite internet options. An LEO satellite option with faster speeds and lower latency than GEO will find plenty of customers.

      • I don't see arctic oil drill camps as being a large enough market to pay for the launch costs.

        They've already got Iridium systems in place. Desktop systems for routine use, and a couple of hand-helds for emergency use - one in the drilling office, one in the life support office (sine life support is a critical operation in arctic work). The wife's worksite had a GLONASS system too - carried on orders from the Russian military.

  • Latency is the problem with satellite packet networks.

    • No it's not - the round trip to low earth orbit at the speed of light is less than 1ms, and the fact that signals travel in a vacuum between sats (rather than in glass or copper along the ground) means that at any distance between end points over 400 miles, latency is LOWER via LEO than via ground signalling systems.

      You're thinking of geosynchronous based systems.

  • Maybe (Score:1)

    by Anonymous Coward

    For varying definitions of broadband. How easy is it to overload a cell network? Each satellite is equivalent to one tower serving everyone under it. One tower for all of Chicago... Would it work as a contiguous network worldwide? Sure. Would it have enough throughput to be called broadband for a significant percentage of the world? I doubt it. Even given incredibly wide bands to operate over the number of customers under it is equally large.

  • Covering the globe with internet via low earth orbit would take a LOT of satellites, or you could use just three. Like these folks are planning. https://www.viasat.com/product... [viasat.com]
  • Hasn't Alaska suffered enough?

    • Re: (Score:2)

      by PPH ( 736903 )

      One of the problems that Teledesic had to solve (not sure if they ever did) was handling the fear on the part of totalitarian governments that it's broadband service could bypass their surveillance and firewalls. How could you convince China or Comcast that you were not encroaching on their exclusive territories?

      • "How could you convince China or Comcast"

        Don't know about China, but my experience was that one does not communicate with or to Comcast. It is an institution with no input ports.

      • Re: (Score:2)

        by thsths ( 31372 )

        Yes, that is a problem - and not just with totalitarian states. India also have severe restrictions on satellite phones - than is another market of 1 Billion people as good as lost. Implementing proper government surveillance for 200 countries and keeping all those governments separate must be difficult.

  • Latency is the Crucial factor (Score:4, Informative)

    by mysidia ( 191772 ) on Saturday December 23, 2017 @04:58PM (#55797585)

    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.

    • According to Wikipedia 2,000 kilometres (1,200 mi) is the upper bound of what's considered to be LEO.

      SpaceX is planning their constellations to be much lower.
      "...the larger groupâ"7,518 satsâ"would operate at 340 kilometres (210 mi) altitude, while the smaller groupâ"4,425 satsâ"would orbit at 1,200 kilometres (750 mi) altitude."

      So somewhere between 1/2 - 1/6 of your numbers.
      And when you consider longer distance communication between satellites, the initial hop up starts becoming irrelev

    • LEO is between 84 and 120 miles. Plus, your calculation was incorrect the correct result is between 1ms and 1.5ms of latency added. However, the communication between the sats in space will be at the speed of light in a vacuum, rather than the speed of electrical signalling in copper, or the speed of light in glass. Meaning that in the copper case, as soon as you're trying to transmit a signal 50 miles, space is the faster router. In the case of fibre connections, as soon as you're trying to transmit mo

      • Meaning that in the copper case, as soon as you're trying to transmit a signal 50 miles, space is the faster router. In the case of fibre connections, as soon as you're trying to transmit more than 400 miles, space is faster.

        It's less than 400 miles to my nearest caching CDN node, helpfully co-located at my ISP's regional central office. My Netflix, iCloud, google content doesn't all come from CA server farms in Silicon Valkey...

    • 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

      No. 1200 miles is 6.4e-3 light-seconds. Also, this topic is about LEO satellites which can be closer than 1200 miles. Furthermore, the minimum added latency due to speed-of-light signal propagation is a small part of the measured delay in previously deployed space-based Internet systems so there's not much intuition to be gained from studying this number in isolation.

  • SpaceX's solution (Score:4, Interesting)

    by EnsilZah ( 575600 ) <EnsilZah@@@Gmail...com> on Saturday December 23, 2017 @05:08PM (#55797639)

    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.

    • Re: (Score:2)

      by marcle ( 1575627 )

      This! The whole point of SpaceX was to make a convincing argument for commercial spaceflight. Convincing in the sense of something that would convince a businessperson.
      Re-use, economies of scale, and efficient use of resources through multi- and re- purposing, make for an enterprise with maximum probability of success.
      Good engineering all around.

    • I suspect that SpaceX will somehow find a way to use excess launch capacity on customer launches to squeeze in a few free LEO internet sats for themselves. (Having said that, I have no idea if that's physically possible with the different orbits that customers need vs what they need.)

  • I hope not. (Score:3)

    by plopez ( 54068 ) on Saturday December 23, 2017 @05:55PM (#55797833) Journal

    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?

    • Re: (Score:2)

      by tsqr ( 808554 )

      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?

      Having a connection requires a connected device at both ends, so people desiring "to live and vacation in places without connections" need only turn off their devices. VLA requires visitors to turn off their mobile devices (or have them in airplane mode and turned on only while taking pictures). [nrao.edu]

      • I know more than a few people that do like to disconnect even if their job requires them to be connected at all times.

        These are the ones that like to leave their phone on, even if they're off-duty, and don't answer calls or "decline" them so as to give the illusion that they couldn't reach the ringing phone in time before it goes to voicemail.

        Being in a place where there's no signal and/or having a device that is "not reachable at this time" means a lot to these folks.

        Once companies hear about practical, co

    • Sounds like a good reason to colonize Mars to me. That is until people put up so many satellites around Mars that no one can be free from internet there either. Then we colonize Venus, and so on and so on. People will be driven to explore every rock in the solar system large enough to build a house. Once we've expended that resource people will be driven to explore other stars.

      Just so they have a place to vacation that's out of reach of the internet.

    • Just turn your device off.

  • The problem is not whether it can be done, weâ(TM)ve done it already. The problem as always is cost.

    Pretty much all of inhabited areas these days has been wired with data-capable systems, even if itâ(TM)s just 56k or DSL for third world countries with a twisted pair. Most areas have wireless coverage of some sort. Whether or not the locals can or want to afford the connection is another thing.

    Putting stuff in LEO or space doesnâ(TM)t solve that problem of either bandwidth or cost, actually it

  • Do the math. First make an estimate of how much solar power your 300 (or whatever number of) satellites can catch. Then multiply that by the conversion to RF power and spread the resulting power evenly over the surface of the earth. You now have power density. Next, calculate the maximum antenna size/directivity a single user can use. His beamwidth can't be narrower than the inter-satellite angular spacing. Next after derating the above result based on necessary link margin for foliage, precipitation loss (

    • Re: (Score:2)

      by thsths ( 31372 )

      Shannon is problem, yes. A single satellite has a lot less bandwidth than a 10GB Ethernet cable.

      But it does not have to be omnidirectional - just like cell phone towers, it could broadcast in bundles, or even use beam forming. Iridium was designed in the 1990s, using technology available at the time. Technology has improved - we will soon have 5G, and space technology as improved, too.

      I think a new LEO satellite phone network would be doable, but it would need to be reasonably competitive with mobile phone

      • Re: (Score:1)

        by n6gn ( 851311 )
        A single satellite can easily have much more capacity than a 10 Mb Ethernet cable. Today's point-point IP radios can easily do 100 times that but a satellite's capacity is spread over a very large area. It doesn't solve the problem if you use beam forming. To cover the whole earth with N satellites, each satellite's available RF power must on average illuminate earth_area/N. That sets the best case power density with perfect patterns. In actuality it will be worse than this. On the ground, each user can no

  • Nothing more to add.

  • What ROI? (Score:3)

    by manu0601 ( 2221348 ) on Saturday December 23, 2017 @08:12PM (#55798251)
    I am surprised to see corporations investing on poor countries. What kind of return on investment do they expect here?

  • ..web..

    Seriously..how about we deal with what we have before asking for seconds .. (i'll wager 50% is a suspect figure)..

  • ever tried to point a dish at a low earth orbit satellite?

    • There are things called computers that are good at doing this sort of routine calculation. Have you heard of them?

  • "The internet has already grown to be available to and affordable by about 50% of the world population," writes Larry Press (formerly of IBM), who's now an information systems professor at California State University.

    FTFY.

  • no one wants satellite internet

Slashdot Top Deals

"The vast majority of successful major crimes against property are perpetrated by individuals abusing positions of trust." -- Lawrence Dalzell

Close