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Honestly, this is just awesome. It's a working demonstration of high-speed satellite internet, showing this approach is a viable solution for "anywhere on Earth" internet.

For all those people who don't have broadband available, this will be life-changing.

It'll only get better from here, welcome to the future :)

(and remember that perfect is the enemy of good)

3 comments

Having this kind of network is a good thing but the idea that any kind of satellite or wireless can replace wires is just fantasy.

Delivering just 10Mbps to 100 million customers is over 900 Tbps. There is absolutely no way a satellite network can clear that kind of downlink bandwidth. And that's just a tiny fraction of the market.

Physical cables/fiber represent several orders of magnitude more capacity and always will. So satellite is great for remote areas or unique situations but absolutely not a substitute for running cables.

Your math assumes all 100 million customers will be downloading at 10Mbps at the same time, all the time. Obviously that is not the case.

Not "all the time", but at any one time - at the same time (eg: watching superbowl - but of course any kind of multicast/broadcast is a little different).

At any rate, it's mostly about the bandwidth each satellite has to route. I don't know what the likely number of subscribers for any one LEO sattelite will be? Will it really be on the order of 100 million notalso served by 4g cellular, dsl and other broadband?

Say for new York state its a large area and population total but the area where you might want/prefer satellite service isn't very densely populated?

Maybe there could be a "broadcast" mode where starlink users can "tune in" to a fixed number of "channels" which broadcast extremely popular content.

Couldn't the satellites themselves cache content that are for world wide events like this?

Edit: Even further, if they're launching 12000 of these couldn't that be a CDN network itself?

    There is absolutely no way a satellite network can clear that kind of downlink bandwidth.

Evergreen comment. Encoding and compression software and hardware continue to improve. The only constant in technology is change. Will we be able to do this sort of bandwith to LEO eventually? Yes. Can we do it this very moment? No one has tried.

There are underlying physical limitations to spectral efficiency. The best modulation schemes in use today can hit about 60 bits per second per hz of bandwidth. Meanwhile, single fibers top out above 40 terabit. To duplicate the bandwidth of just a single fiber link with a radio downlink, you'd need over 600 ghz of available spectrum. That'd require advances pushing deep into the thz gap, but beyond that, the physics of propagation are so different between 6 ghz, 60 ghz, and 600 ghz that it's hard to conceive of a single system covering so much spectrum. And that's not even getting into issues with geometric limitations of radio beam widths.

While change is constant, this isn't an argument that any change you can imagine is physically realizable.

Fiber is here to stay for a very long time precisely because it starts out with such massive fundamental physical advantages. It's also a mistake to assume innovation only benefits one alternative. We're still learning how to make and run fiber cheaper too.

> 60 bits per second per hz of bandwidth

Between one transmitter and receiver. Starlink is designed to cheat Shannon by utilizing SDMA on a truly massive scale. Every antenna in the system, both on the satellites and on the ground stations, is a large phased-array antenna, capable of simultaneously emitting different signals on the same wavelength in different directions, and capable of discriminating between multiple different signals on the same wavelength that come from different directions.

This is how Starlink intends to push so much throughput over just ~50 GHz of bandwidth. Not by pushing more bits per hz per link, but by filling the sky with hundreds of simultaneously visible satellites, and having each of them to all use all of the available spectrum at the same time on every link between any of them and any of the ground stations.

For what it's worth, satellite is typically around 1-4 bits per second per Hz.

Context is important, though. Network performance advances are always relative. If satellite fully-congested download speed improves 10x while hardwire link performance improves 10x, satellite will still be perceived as "too slow" by some segment. Our experience thus far has been that advances in applications tend to consume the bandwidth available. Whether that trend continues remains to be seen. (To be fair, I have never saturated my bidirectional 1GBps fiber link and I don't foresee ever doing so except for very brief periods of time.)

> Encoding and compression software and hardware continue to improve.

But these would apply to both wired and wireless, no?

If encoding tech is specific to wireless then not really , just like improving cable medium , number of cable pairs etc will not improve wireless , better transmitter or receiver will not impact wired

> Encoding and compression software

What does that have to do with bandwidth ?

Sending less data over starlink (which is not tcp/ip btw).

I’d you can make 10Mb suddenly only require 900k of actual raw bandwidth by say adding a fpga or something then you can increase throughout to the users.

And even in remote areas, building out VDSL2 networks with relatively decent speeds (200Mbps down and 100Mbps up[1]) would be better, honestly.

Most homes already have a phone line and can support a DSL network... and in some countries a phone line is mandated by law, so the infrastructure already exists.

But, DSL is not nearly as "sexy" as thousands of satellites...

[1] https://en.wikipedia.org/wiki/VDSL#:~:text=VDSL%20offers%20s....

Even if DSL can get there, reliability of the connection in rural areas is often very suspect. A tree falls over in a winter storm, a bad crash that takes out an exchange box, a pole just plain falls over due to shifting ground, or maybe construction takes out a main trunk... these problems happen in cities too, but in a city you have maybe 1 km of infrastructure to worry about. In rural areas you could have 100 or 200 km of infrastructure just waiting for a calamity. Even just as a reliable alternative Starlink would be a big boon to rural users.

> Even just as a reliable alternative Starlink would be a big boon to rural users

Starlink is susceptible to cloud cover, rainstorms, lightning and other things that would interfere with signal quality (or render it unusable for periods of time).

Seems buried lines (either POTS for DSL, Coax for Cable, or Fiber) is the best solution. We just need to figure out how to incentivize it being built.

I haven't personally deployed VDSL2, but I have deployed DSL and other data-over-twisted pair systems including recent G.fast, G.hn and MOCA. I strongly doubt that VDSL can achieve those kinds of speeds reliably at the distances and densities needed to provide this service to the areas that need it most. In rural areas the copper lines are too long and too old to achieve these speeds (but they're fine for voice/POTS, so there's no mandate to upgrade.) Twisted pair is also really susceptible to noise and crosstalk, so in more densely populated areas once you start doing DSL to a lot of customers whose cables are bundled together they start to interfere with each other and everybody's service gets bad. In both cases the problem is signal to noise ratio - long cables mean poor signal, density means high noise, and twisted pair copper just isn't designed to deal with either very well.

What about VDSL2 Vectoring (G.vector)? Seems like it mitigates most of the crosstalk problems - but I admit I'm not an expert on DSL deployments.

It seems VDSL2 can achieve maximum throughput at run lengths under 1000ft from the DSLAM, with maximum performance beginning to degrade after. That sounds sufficient for most of the people currently stuck with slow access right now in the US (more rural areas outside major cities, but not actually remote as-in nearest neighbor is 1 mile away).

Also... surely solving this problem is cheaper than sending thousands of satellites into orbit every few years as they decay.

True, but their first customer is the U.S. Army which tells me this networks primary purpose is the same as the original intent of the internet itself. A mobile network that is available and reliable anywhere. Civilians usually get to do all the beta testing and provide feedback that improves the technology.

Also many of the places I have been looking at moving to don't even have POTS lines. This would fill the gap where POTS and VDSL is not available. I would certainly use VDSL if that were an option and use Starlink as a fallback in a very remote area.

> Also many of the places I have been looking at moving to don't even have POTS lines

Where are you, if you don't mind telling. I had thought, perhaps incorrectly, that in the US it was required by law to have POTS lines run to all homes - which led to it being installed during construction.

I mean, you're not wrong, VDSL in rural areas would be great! But it also hasn't happened.

The range just isn't there even for suburbs. The high speeds are only achieved with line length of less than 500m, and at 1600m it's similar to ADSL2... So not really a effective solution.

> And even in remote areas, building out VDSL2 networks with relatively decent speeds (200Mbps down and 100Mbps up[1]) would be better, honestly.

I live in the suburbs of Paris and the length of the phone line is still too long for VDSL2 (it's only available for distance less than 1 km) so I am not sure how feassible that is in rural areas.

I think they serve different purposes. Satellites serve areas where they can't run wires or it's insanely expensive for too few people. Think very rural areas and war torn areas. Imagine being able to get unblocked internet in China by using satellites? Or in Belarus. Or the middle of Amazon (rainforest)?

People keep bringing that up as a common use case, but how do you propose that people in China or wartorn countries will get their hands on the modems they would need to use Starlink?

Possession of unauthorized satellite equipment is as good as getting caught red-handed at a dead drop. A paranoid security state wouldn't blink at executing every such person as a spy.

Will Starlink even be able to legally sell internet services in China? Would they not have to comply with CCP's censorship policies and disconnect people at their will?

I strongly disagree with CCP's policies here, but that's not for us to decide.

In rural areas, we have LTE-based FWA.

10 MHz wide channel with 256-QAM can push 100 Mbps down.

I'd argue if you get 100 Mbps down, you're not all that rural.

Economies of scale work massively in your favor in this situation. You definitely do not need to sell the bandwidth 1:1, and the more customers you aggregate the more you can oversell. With 1gbps upstream bandwidth you can comfortably provide 1000 customers with 10mbps Internet service and they will virtually never see speeds lower than 10mbps.

> Delivering just 10Mbps to 100 million customers is over 900 Tbps.

50 Gbps * 12000 satellites is 600 Tbps.

Most of those satellites will be over the middle of nowhere at any given time. But those customers don't use 10Mbps 24/7 either.

It also may not be limited to 12,000 satellites. They're seeking approval for up to 42,000.

Oct 2019: "SpaceX submits paperwork for 30,000 more Starlink satellites"

https://spacenews.com/spacex-submits-paperwork-for-30000-mor...

100Gbps microwave links have been shown on land. If you take that as a theoretical limit, 12k satellites can give you 1200Tbps.

That's not comparable to sending a signal from space.

I'm pretty sure it could with that DIDO technology that Rearden Labs produced. The think the sub company they started it under was Artemis. I always thought they're tech would work very well with satellite constellations.

Artemis was vaporware. It never made it into the field.

Vaporware is not an accurate description. I'm pretty sure you they have manufactured hardware that you can deploy for a test deployment. Also pretty sure they're working with the military for weaponization and wireless power transmission.

And yet such a satellite network is being built and deployed.

The people building this have obviously done the math and have a solution which they're implementing while you're busy saying that it can't be done :)

10Mbps to 100 million customers equating to 900 Tbps would be more akin to serving 1 billion customers, since on average someone isn't even close to saturating their bandwidth.

One satellite cannot route 900tbps of course , just like your local ISP cannot handle that either .

However over 40,000 satellites that’s just 22.5 gps per sat , quite achievable

I’m still not sure we won’t get develop Kessler Syndrome (runaway debris situation in LEO) so let’s hope you are right.

LEO is not as much of a problem as higher orbits. At the height that Starlink operates unpropelled debris falls out of the sky relatively quickly due to drag.

The greater the surface area the quicker the decay. So if these satellites naturally fall after 3-5 years that means that if they somehow collided with each other creating millions of pieces of debris they would clear out with in less than a year because of the loss of energy during the collisions and the increased surface area.

I wonder what happens on a cloudy day.. currently the satellite based DTH television displays a cloud and refuses to work. Technically is there a work around to that?

Cloudy days will 100% affect internet speeds. But it's also possible for them to have better equipment at LEO due to lower launch costs to overcome that affect.

It's kinda funny because cloudy cover are a smaller portion of signal loss at GEO, (most loss is due to distance), but it affects that signal quite a bit once satellites are tweaked to get signal to Earth. Most GEO satellites try to have something like 95+% uptime due to average cloudy days in an area, which means they account for those really bad days where the clouds are just too thick. They use weather stats to project how much cloud cover each region will get so they can build bigger beams for that area.

In the past those beams would cover large areas (Like the entire USA). Now they're getting smaller (State Sized) so they can tweak how much signal could go to say Washington vs. Idaho. They're always trying to make this stuff better. But those newer sats at GEO cost 300+ million dollars per sat and are expected to last 20+ years. So it'll be a while before this new generation of GEO sat is out there.

The workaround would be. More signal power at the satellite (costly), or you as a consumer get a bigger/more powerful receiving antenna.

Existing satellite internet doesn't go out with clouds, and only with heavy rain.

Well, on a rainy day both LTE and point-to-point wifi here go bad anyway, so it's still an improvement (more signal routes = more chance one works).

People keep comparing Starlink to their ideal non-rural internet connection. That's not what it needs to compete with.