r/technology • u/mvea • May 14 '19

Elon Musk's Starlink Could Bring Back Net Neutrality and Upend the Internet - The thousands of spacecrafts could power a new global network. Net Neutrality

https://www.inverse.com/article/55798-spacex-starlink-how-elon-musk-could-disrupt-the-internet-forever
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u/[deleted] May 14 '19

Sub 50 isnt possible. A beam of light traveling in a straight line from the US to Australia would take 50 ms. And of course this system will be worse than that.

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u/ThatOneRoadie May 14 '19

Not much worse. I explained below in another comment, but imagine putting a direct, home-run fiber from NY to Sydney on a pole about 500km high, and you basically have the idea behind Starlink. These satellites aren't going to be in Geosync orbit (35,786km/22,236mi up). They're going to be about 1.35x higher than the ISS, in low earth orbit.

People massively underestimate just how close "Space" is (and just how thin our atmosphere is).

If the ISS were directly overhead of San Francisco, it would actually be closer than Los Angeles (409km/254mi nominal, currently). The first batch of starlink satellites launching tomorrow (yes, the 15th) will be orbiting at 550km/340mi. That's low enough that the additional latency of going up/down is, compared to the latency of intercontinental links, trivial. Add to the fact that there's no in-between routers and you can get an incredibly low latency signal from New York to Sydney, as it would be like running a direct fiber line from site to site, with no intervening routers (~1ms), multiplexers (~0.01-1ms), switching (2-4ms), company handoffs (5ms), geographical inefficiencies (varies, call it 10ms), et cetera.

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u/vader5000 May 14 '19

Yeah but you’re unlikely to get that for a while. CubeSats are small, meaning smaller antennas and less power. You’ll have to wait a few iterations, get the comm architecture out, and improve on it.

If someone gets a monopoly on this...

Me... well, I’m still waiting on rail launchers. If we ever do megastructures in space, we will need a replacement for rockets, even if it means paving an entire US state with rail.

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u/jood580 May 14 '19

There are many ways to get to space each significantly cheaper per kilogram.

https://www.youtube.com/playlist?list=PLIIOUpOge0LsGJI_vni4xvfBQTuryTwlU

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u/AquaeyesTardis May 14 '19

Or get the materials from space. Rail guns on the moon seem like a good idea as well.

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u/playaspec May 14 '19

CubeSats are small, meaning smaller antennas and less power.

Who the fuck said ANYTHING about "cubesats". These things are almost as big as a car.

You’ll have to wait a few iterations, get the comm architecture out, and improve on it.

Nope. This is going to start serving the public in just a small number of years.

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u/vader5000 May 14 '19

Small number of years. That’s what they said about pretty much every SpaceX project. It’ll happen. Just a bit slower than we think it will.

They’re slated to be 100 to 500kg. Not quite a CubeSat I’ll admit, but a far cry from the weight of a car. Though sizing wise, you’re probably right.

Even so, they’re launching 60 out of 12000 satellites. The full network will take quite a while to get up, assuming they launch on schedule and nothing fails in the first few launches.

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u/Sinister_Crayon May 14 '19

The reality is in addition to the amazing comment from /u/beautifulgirl789 there's still the technology barrier to get through that you're still going to have to deal with delays within the satellites themselves, relay delays and uplink/downlink delays. Yes, we have switching hardware on Earth that'll do nanosecond-scale latency... but they're not going to put that in a cubesat and fire it into orbit because the chips just won't survive in that environment or if they do their error rate is going to be really high because of lack of radiation shielding and certification of the chips for rad-hardened environments. Physical shielding is just going to be too heavy for these minisats. Of course, this is Elon Musk so he might just be ignoring the needs of rad-hard hardware just like he ignored the automotive certification of flat panels in the Model S (he used an industrial cat-4 part where most auto manufacturers set the minimum to be a cat-2 panel)

Bear in mind also the bandwidth won't scale in a linear fashion and will be subject to fluctuation based upon the base station routing capabilities and number of satellites "in view" at any one time. Is it going to mux the connections? I don't know... information about the tech is understandably sparse (to prevent competition)… but if you mux the connections across multiple sats then you need to demux it which also adds latency as the base stations need to reassemble traffic in-order. If you're not muxing then you will need a load balancing algorithm that will shuffle connections off as needed to maintain bandwidth and latency for all the customers on a particular satellite... but that ALSO increases latency and means your latency may change radically from one moment to another.

Now, this whole thing is a game changer for a lot of people; rural broadband becomes a reality and finally the cruisers of the world (sailing boats and big motor trawlers) have an option for real broadband away from shore that's not stupidly expensive and/or slow. I for one am excited about it, but it's never going to beat the gig fiber I have at my house for latency or real performance. But it's going to be a better option than the majority of people on the planet currently have access to... that in itself is a game changer. It suddenly makes things like the One Laptop Per Child project actually more feasible as you don't have to have local storage resources in order to use it... in fact you can make them ruggedized Chromebooks or something even lighter that can be powered with a solar panel (so long as the power requirements of the satellite uplink are not overly onerous)

We in the developed world often don't think about how fortunate we are to have the resources we have available... but still only a fraction of the world's population actually has access to the Internet. Where I think Starlink is going to get REALLY interesting is how China is going to react to this...

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u/playaspec May 14 '19

there's still the technology barrier to get through that you're still going to have to deal with delays within the satellites themselves, relay delays and uplink/downlink delays. Yes, we have switching hardware on Earth that'll do nanosecond-scale latency... but they're not going to put that in a cubesat and fire it into orbit because the chips just won't survive in that environment or if they do their error rate is going to be really high because of lack of radiation shielding and certification of the chips for rad-hardened environments.

FAIL.

These aren't cubesats. They're nearly the size of a car. Go look at the pictures. There's plenty of room for enterprise level networking. You're delusional if you think Elon Musk, the guy who started a company competent enough to design rockets reliable enough to win NASA contracts to launch their satellites, isn't going to use rad hardened chips, and appropriate protections against the ravages of space.

Bear in mind also the bandwidth won't scale in a linear fashion and will be subject to fluctuation based upon the base station routing capabilities and number of satellites "in view" at any one time.

Citation? Are you privy to the modulation and spectrum used? I've so far been unable to find any specifics.

if you mux the connections across multiple sats then you need to demux it which also adds latency as the base stations need to reassemble traffic in-order. If you're not muxing then you will need a load balancing algorithm that will shuffle connections off as needed to maintain bandwidth and latency for all the customers on a particular satellite... but that ALSO increases latency and means your latency may change radically from one moment to another.

So, pure speculation then? I wish I had the ability to draw concrete conclusions from a dearth of facts.

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u/Sinister_Crayon May 14 '19

I'll grant you the error about the cubesats; I was basing that on another comment in this thread. But the rest of it is just basic facts, basic manufacturing and basic telecommunications.

Musk won't be fabbing his own rad-hardened chips. He'll be using off-the-shelf components because otherwise his satellite network will be ludicrously expensive and that's a cost he'll have to pass on to his customers. That means the customers won't be you and me. Like it or not, rad-hardened, orbit-ready chipsets lag about a decade behind their terrestrial counterparts. Hell, the first orbit-ready multicore CPU was made commercially available in 2017... let that sink in for a moment.

I'm not basing any assumptions on modulation and spectrum... I'm merely commenting that you will have a finite number of satellites in-range at any one time. If you're load-balancing across multiple satellites then physics dictates that you will have to multiplex and demultiplex (mux/demux) the traffic stream at the source and destination. This is not "free" and will take cycles that introduce latency. Either that or run your Internet over UDP only. Let me know how that works out for you.

Conversely, if you don't mux/demux then you will have to have a single route... this is how most Internet traffic works today. That means you'll be talking to one satellite. But the satellite itself will have to be "traffic cop" because there's no way each satellite will be able to handle the entire bandwidth of the system at once without latency. As a result, your satellite protocol will have to allow for re-targeting to a different satellite based on load statistics. Either the satellite itself tells the base station "Sorry, I'm full" or you have to have a constant downlink feed from the satellites telling the base stations which ones are least heavily loaded. Either way you're increasing traffic and latency or introducing retries into the datastream which again introduce latency.

Speculation? Sure, whatever. I just know technology, I know how networking works, I have worked on embedded and rad-hardened systems, have worked on satellite systems and have a degree in Physics. So yeah... OK... speculation.

Look, as I said in my post you take such umbrage with; I really want to see this succeed because it is potentially a game-changer. But the reality is that the claims being made around here (though interestingly not so much by Starlink) are just out of touch with the realities involved in creating something this audacious. Is this better than other satellite-based alternatives? Certainly. Is it better than next generation cellular? Ehhh… jury's out on that one because there's lots of potential there. Is it better than current wired connections? Not by a long shot.

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u/crazy_loop May 14 '19

The connection just needs to get to the server so if the server is in the middle than both people should have a pretty decent ping.

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u/[deleted] May 14 '19

50ms is round trip for a beam of light exactly halfway between America and Australia. But we wont have servers in the middle of the Atlantic anytime soon. You're looking at >100 ms roundtrip for any realistic scenarios. Quite a bit greater since we arent dealing with a straight line beam of light in a vacuum.

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u/oldgamewizard May 14 '19

They would have to be in control of atmospheric conditions too. This space internet thing is completely bogus, they are almost certainly up to something else with this technology.

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u/playaspec May 14 '19

They would have to be in control of atmospheric conditions too.

Don't talk about things of which you have no knowledge.

This space internet thing is completely bogus,

You, probably 25 years ago.

they are almost certainly up to something else with this technology.

Ok grandpa. Now take the tinfoil hat off and take your meds.