SpaceX Gets FCC Approval to Sell Wireless High-Speed Home Internet from Space | Hacker News Reader

SpaceX Gets FCC Approval to Sell Wireless High-Speed Home Internet from Space

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797 pointshsnewman524 comments

Every story about SpaceX satellite Internet (Starlink) is plagued by questions about high latency. I think Elon needs to plan on spending a lot of marketing money to overcome this specific misconception.

Starlink latency is quite good. LEO is a lot closer than GEO (less than ~1000 km* vs 35786 km.) SpaceX actually intends to compete with terrestrial systems on latency; many important routes will have significantly lower latency than any feasible terrestrial system.

Remember, fiber isn't latency free. It isn't even speed of light. It's about 70% SOL. Radio, on the other hand, is SOL (or so close it doesn't matter.) So there is a cross over point where the latency of a LEO satellite system is actually superior despite the uplink/downlink path.

*depending on which orbital "shell" is involved. figures range from 340 km to 1200 km.

SpaceX actually intends to compete with terrestrial systems on latency; many routes will have significantly lower latency than any feasible terrestrial system.

I would like to see a framework, where the backend of a cloud system can migrate opposite to the direction of orbit, so the same virtual cloud server could remain (by 'hops' where it serializes a copy of itself, then fails over to the copy) more or less geostationary. Such migrations would happen as seldom as once per 10 minutes.

My game server cluster isn't too far away from having such a capability. (I was planning a variety of capabilities, such as using cheap GCP "ephemeral" instances by quickly failing over to such copies.)

This is basically vmware's vmotion feature.

That's quite cool. I'm doing my feature at more of an API level. That said, many applications still need to be architected to do this sort of migration well. The turnkey version just guarantees a demo version. (As technology develops, the turnkey capability will increase, but people's demands on the technology will also increase.)

Why would you need to do this? The constellation still needs downlinks - and the downlink nearest the physical location of the user should always be where that traffic pops back onto the Internet.

For a game server cluster, I would be running a game loop implemented as a series of pure function functor-like objects, located "very near" a spatial database. In that case, I would be migrating to provide the very lowest latency, as if the system were running on a "geostationary" server just a few hundred miles overhead. (Which has to pause for a quarter second, once every several minutes.)

That sounds like a terrible experience. You want to avoid latency spikes at all costs. People might not like latencies as high as 100ms to 200ms but it definitively is possible to enjoy a laggy game like that. Suddenly getting a 500ms latency every minute will cause a lot of weird and unfair situations that can basically ruin the entire game.

I agree, jitter bigger than a synchronization time is worse than high latency. When player have high latency (and I was in top3 on NA Solo ladder in League of Legends while playing from Urals with 220ms), he could only predict the moves of the opponent because what you see is far behind the server state, but with stable latency he knows the exact delay between an input and registering it on the server which puts less pressure to mind to deal with desynchronization between the picture on a display and the actual state.

I agree, jitter bigger than a synchronization time is worse than high latency.

I'll always grant that fast twitch FPS will always have a problem with this. That's not the genre I'm interested in creating games for, and it's not what my server framework is designed to support. (It is real-time action, but the pacing is more akin to RTS than FPS.)

I didn't say that high latency isn't frustrating. But you can effectively shoot the air on the route of the opponent where you'd think he would be by the time server would have your input.

That sounds like a terrible experience.

The usual latency should be on the order of 30-40ms round trip.

Suddenly getting a 500ms latency every minute

No one said anything about that. The client should have some form of dead reckoning, and there should be an edge server that maintains connections. With the right kind of game mechanics, no one notices the server disappearing then reappearing behind the scenes. I cite 250ms as a worst case. It should be possible to get the impact as low as the server skipping one frame every few minutes. The clients don't need to skip any frames.

the edge server in this case would need to be in space, on a satellite.

That's going to be a very expensive edge server!

A bit off topic but what does the word 'constellation' mean? A quick Google didn't yield much, and I'm not entirely sure what field it's from. My guess is "a set of connected satellites"? Or is it more specific than that?

https://en.wikipedia.org/wiki/Satellite_constellation

Ahh thank you!

If only there was a large mass of rock and mud that was geostationary.

Wait, what? Are you planning to put your game server in orbit? Because otherwise I don't understand what you're asking - a server on the ground will always be "geostationary" - it's the satellites it talks to that will change.

He's halving altitude to 550 km, in ideal cases bringing latency to 15 ms. Some satellites will be even lower, 350 km, for populated areas. https://arstechnica.com/tech-policy/2019/04/spacex-changes-b...

I presume that's just one direction?

Is it 15ms to the satellite? If so, that's like 30ms to land, which would negatively impact gaming if it still needs to travel from where it lands to the end goal (via normal pathing?)

30ms is a good ping for games...

edit - yeah I forgot about the endpoint then to the game servers data center

The 30ms figure is just the earth->satellite->earth part though. It still has to go through terrestrial wires to the server, and then be processed, and back through wires to the transmitter.

Datacenters make deals with network providers. Why should it be any different with Starlink?

That's not 30ms ping, that's add 30ms ping.

Not always I don't think.

Maybe from me to a geographic location 400 miles away, yes. But what about 4k miles away, like coast to coast?

That would probably depend on how many satellites it has to bounce through and how far it has to travel terrestrial, but I would think there is a geographic distance where that 30ms is faster.

Up to three. After one bounce, it can be redirected into a geostationary or a polar satellite where the final bouncer would reach its LEO peer again.

That statement assumes no transmission latency on your current setup. Kinda doubt that's the case.

30ms would be you and the game server both on Starlink, on the same satellite. Otherwise, you have to add that to the latency between the ground station and the target server.

IIRC, the plan with Starlink is to have many stations that are supposedly easy to operate in many large-ish datacenters in major areas as opposed to systems like Iridium which have few, complex downlink stations in comparison.

A 550km trip at the speed of light should take just under 2ms. It looks like they've accounted for the other stuff.

I mean, I'm a gamer but really... its pretty low on the list of important reasons to support such a project.

1000 km / speed of light = 3.34 ms. Suppose you want to ping a server next door to you and your ISP is a satellite 1000 km away. The distance your signal travels is 1000km from client to satellite, 1000 km from satellite to server, 1000km from server to satellite and 1000km satellite back to client. 4000 km at the speed of light is 13.34ms (the transceiving latency is probably negligible in comparison, though I'm not 100% sure about the DSP requirements for this sort of system)

If the target server is far away and the signal goes 7000 km from satellite to satellite in space before coming back down, then your signal it will need at least 46.7ms more in space for a 14km round trip in space, which results in a minimum possible ping of 60ms to ping a server 7000 km away. Fiber-optics are 30% slower than radio links, so this 60ms minimum is 10% lower latency than the best fiber-optics can do: (7000 km / .7 speed-of-light) = 66ms

If the distance to your server is 2.333x the distance to your satellite you will have lower latency with radio than fiber optics. Bringing the altitude of the satellites down will make a big difference, but you also need a lot more of them in a constellation to have low average distances.

But for something more realistic for gaming, a player in Boston hitting a server in NY. The fiber message travels something like 200 miles, while the satellite message travels 2,200 miles.

Boston to New York is 215mi or a 430 mile round trip. At 200 miles up where they intend to put the satellites orbiting over major cities, it's going to be about 1000 mile round trip.

I thought that the US servers for most games are in the middle of the country to get the best average ping for a cross-country audience. Blizzard is like Chicago and Texas.

Not usually. In my experience, they usually follow the typical popular datacenter areas e.g. East Coast/West Coast. I've mostly only seen really popular games offer Central locations like Dallas/Chicago. But it's getting a lot better now that vultr (COD uses them) and other VPS providers get more and more locations.

Nope, the biggest AWS region is in Virginia (as well as a bunch of others, energy is cheap there). There are also lots of datacenters in Dallas, TX and San Jose, CA. NYC has a lot of connectivity (throughout the northeast, and transatlantic) but the cost of real estate is so high that it is uneconomical to operate lots of large datacenters there.

The majority of the population in the US is in the eastern half (1/3 in states on the East coast), so you don't actually decrease median latency by putting datacenters in the geographic center: https://commons.wikimedia.org/wiki/File:United_States_popula...

Nope, the mean population center of the contiguous United States is somewhere west of St. Louis.

https://en.wikipedia.org/wiki/Mean_center_of_the_United_Stat...

Actually not too far away from the geographic center which is somewhere in Kansas.

That doesn't disagree with what I said. The majority is still in the East (the mean is East of the geographic center), and you don't want to optimize for average latency anyway. You'll get the best median latency with two datacenters by putting one on the mid-Atlantic coast (~180M people East of the Mississippi) and one on the mid-Pacific coast (another 50M in Pacific Coast states). That means the latency for ~2/3 of the population is way lower, and the max latency is still about the same as putting them in the center of the country.

> Boston to New York is 215mi or a 430 mile round trip.

Assuming terrestrial lines travel as the crow flies, which is not all that likely (but probably not too far off).

> At 200 miles up where they intend to put the satellites orbiting over major cities, it's going to be about 1000 mile round trip.

Other people here are noting that fiber signals travel at ~70% the speed of light, while radio waves travel at very close to the speed of light. If that's true, it puts the optimal time for land based optical communication at ~3.3ms[1] ms, while the optimal time for a low orbit satellite at ~5.4ms[2] (if I didn't screw up the math). That's slower, but not by a whole lot, so it might even be better than you're predicting.

Also, are people actually getting sub 4ms round trip times between Boston and New York? If not, then the difference here might be entirely subsumed by other factors.

1: 430 Miles / 186,000 M/s / 0.70 = 0.0033 s

2: 1000 Miles / 186,000 Miles/s = 0.0054 s

Radio waves are faster than light going through a fiber optic cable, and the satellite mesh network will have fewer hops (switching packets on fiber is expensive time-wise).

The difference in latency won't be nearly as bad as a naive comparison of these two numbers would suggest. Depending on what hops your terrestrial traffic is going through, the satellite transmission could well be faster. To give you a trivial example, I'm seeing 11 ms ping right now to a server within my own city, that's only a couple miles away. This is ~0% signal transmission delay and ~100% switching delay.

It's still transmission delay, you are underestimating how fast routers forward packets today. Likely the server has a different provider and them and your ISP does not peer in your city, so you have to go somewhere else where they peer (or where their transit peers).

I think no ISP would connect to others with a huge coil of fiber to add that amount of latency.

No? But they do not connect to each other in every city either, which is why you can get this delay even if both parties are in the same city.

All the uplinks of my ISP with one exception (carrying traffic through various lines up to european IXs) are connected to the Internet through the same MSK-IX which is 900 miles away from my city and adds 4ms latency. I don't think GGP's traffic route is that long though.

Not sure what you are talking about. 900 miles is ~1500km, 1500km at the speed of light in fiber (2/3 of SOL) takes 7,5 milliseconds, so 15ms roundtrip.

But I don't see why it's relevant. Forwarding in modern ISP routers is on the tens to hundreds of microseconds level, even if there are many hops it does not add up to that much. So what he has is likely not "switching delay", and even saying that 11ms is 100% switching delay when it's the same city (low amount of hops even if multiple ISP's are involved) is just ridiculous.

> takes 7,5 milliseconds, so 15ms roundtrip.

Took that number (it was for one way trip though) from memory, might be scrambled. Just checked, RTT 17ms with 3ms jitter for me.

22ms RTT is still too much though. Even with centralized network for cross-border traffic like in my country, there are IXs way closer than those 1500km to any town on european part and obviously to the East of Urals (the longest distance between IXPs is ~3000km for Krasnoyarsk-Khabarovsk, the longest distance to the closest IXP of 1500km have Norilsk - the most northern city on the globe and it's satellite Dudinka).

edit: fixed some english.

So maybe satellites simply aren't the best-use case for gaming?

I don't think Elon is counting on gaming to be the backbone of this service.

Rural customers are use to 100+ ms response time. Even getting 60 ms response time would be a major improvement for many customers.

Has anyone published the expected lifetime of those satellites? At the lower end of that altitude range the drag is going to be pretty severe.

The high latency questions are only from people who really don't understand the industry. The question most analysts in the industry ask are about how they plan to be profitable.

"People who don't understand the industry" describes nearly all potential customers. I don't think this refutes the GPs point.

Most potential customers don't know the difference between bandwidth and latency, they just think of it as speed.

I disagree. I think people equate bandwidth with speed, because that's what all of the commercials and marketing materials say. Latency is hardly ever mentioned.

Put the average consumer on a gigabit connection with 5 sec of latency and ask them how fast it is.

Yes people have been burned by HughesNet and garbage like that. But it won’t take much to educate them, people can understand the difference. A simple graph showing the ping times and people will get it.

I suppose this argument works really well on HN. how many people do you think know or care about a ping time? if they did, don't you think we would see all of the commercials for broadband bragging about their latency instead of bandwidth? Streaming media dominates the internet today, and that's unaffected by high latency.

Steaming media is particularly poor application for Starlink, which is starved for bandwidth.

I agree, but that's the opposite of what people think.

ATSC 3.0 is a possible avenue for offloading some streaming traffic. It seems that the consumer hostile packages we've come to love are taking shape and 2020 may see some adoption...

https://www.atsc.org/newsletter/atsc-3-0-where-we-stand/

Is there a writeup anywhere what the bandwidth and latency is likely to look like? I assumed the latency would be worse that that of a land line.

It depends. If you're connecting to a data center across the street, the latency will probably be worse. If you're connecting to one on the other side of the world (or somewhere where the packets have to take a more circuitous route), the latency might be better. The satellites aren't that high up so latency won't be a huge issue.

I think bandwidth limitations will be more problematic. The Earth is really big, and there's not really a good way with LEO orbits to focus your satellites over urban vs rural areas. IOW you can focus coverage on lower latitudes but not really certain longitudes.

IIRC previous FCC filings said each satellite would have ~20 Gbps of bandwidth. That'll be great if you're in a rural area, and I think the gigabit speeds some people are hoping for are actually possible in certain situations. However a lot of people think that they're going to be able to replace the Wifi router in their apartment with a Starlink antenna... I don't think that will be practical any time soon. I'm not an RF person but I doubt there's enough spectrum for each satellite to have tens of thousands of users simultaneously.

edit: also, like with 5G the signal quality is going to be crappier when it is rainy or cloudy.

It's going to be a similar situation to cell phones. When you purchase the product, you know that it will be slow some times outside of your control, but that's the trade off for being able to get connectivity almost anywhere. With no hassle as long as you can see the sky. On your boat? Sure! On your farm 30 miles from anything? Sure!

It will be interesting to see if they geo-lock the base stations or will allow you to move them and then re-calibrate/re-register your location for load balancing.

There will need to be some level of geo-locking, since the price variation between poor/rich countries will likely be 10x

Latency, yes: http://nrg.cs.ucl.ac.uk/mjh/starlink-draft.pdf with a nice video of the simulation here: https://www.youtube.com/watch?v=AdKNCBrkZQ4&feature=youtu.be and a bunch of vidoes that include updated information here: https://www.youtube.com/channel/UC-k1j7M2-hBfXeECd9YAQ_g

Bandwidth, not to my knowledge. As the nice paper above says its too speculative.

Nothing official.

Thanks, great video.

Imagine every one of those satellites running BGP!

They probably won't... Links between satellites will use a different routing scheme. Traditional network protocols will "disappear" at the sending ground station, only to "reappear" on the receiving one.

A video link of a simulation was posted on a different comment that shows the "routing" between multiple satellites.

Why wouldn’t they use something like BGP to route between the satellites? Because the topology is explicitly known ahead of time and so the routing can be more “hard coded?”

An interesting side effect of this network is that latency experienced by any two users, anywhere on the network, should be close to equal.

Being profitable is their problem (I can purchase a connection from someone else), but latency is something I have to worry about.

High latency has been the dealbreaker for satellite internet. No one wants to use satellite internet if they can avoid it.

How badly does "weather" affect TCP latency over an LEO satellite internet pipe?

Depends on the frequencies being used. Starlink is in the ku and ka band so it will be affected by weather, especially heavy rain or snow(called rain or snow fade in the field)

Standard solution to rain fade is to make sure you have a power budget and can ramp power when heavy rain starts.

Thanks! Especially thanks for the terminology, that's very helpful to look up more about it.

Here is a neat simulation of a proposed network: https://www.youtube.com/watch?v=QEIUdMiColU

Admittedly I haven't researched it that well, but I'm curious how often they would have to aim their sensors at the sun to receive from a neighboring satellite. I'd have to assume those links would need to be subtracted from the system, which could slightly drive up latency around sun up and sun down for a part of the planet.

The sun is pretty small compared to space, something like .0005% of the full sky sphere, and almost half that time it's covered by Earth. Since there's no atmospheric glare in space, I suspect it's not a problem given decent engineering.

There are still internal reflections within the optical system - glare from that will likely be much larger than atmospheric glare

Given communication is point-to-point, and very coherent, I'd think this is extremely easy to solve if glare in the system was a real issue. Aim the receiver through a tube (or array of tubes) painted black, for instance. Certainly easier than building an equally precise telescope.

Could you define the acronyms you use please? LEO, GEO, SLO

LEO - Low Earth Orbit

GEO - Geosynchronous Earth Orbit

SOL - Speed of Light

I believe:

LEO - Low earth orbit (close to the earth)

GEO - Geostationary equatorial orbit (further from the earth, more efficient in terms of energy required to maintain a fixed position[1])

SOL - Speed of Light (a limiting factor in fiber optic communications - and over the air communications as well)

[1] From reading a bit, maintaining a fixed position relative to the ground at lower altitudes involves a constant velocity adjustment in the form of fuel expenditure - the equilibrium for each orbital period corresponds to a single altitude, so different orbital periods (when minimizing fuel usage) imply different distances.

Re [1], you generally can't do fixed positions anywhere else but GEO. Trying to stay stationary at a lower altitude would require using amounts of fuel that are way beyond what we can put in space.

Note that GEO satellites do carry fuel with them for "stationkeeping" - between errors in navigation, variation of Earth's gravity (due to it's irregular shape and composition) and influence of solar radiation and other celestial bodies, those satellites do have to occasionally and very slightly adjust their orbit to stay stationary.

Sorry yes, I was trying to express that but I think it came across unclearly - maintaining an unstable orbit requires a constant expenditure of fuel.

The problem I have heard isn't so much latency but path to profitability. Unlike GEO satellites, LEO based internet is not going to be fully operational until a significant number of satellites are up there to provide continuous coverage at a single point on earth. Financially, this makes for a very front-loaded-capital / debt-intensive business which will falter unless subscriber numbers and technology all pan out exactly as estimated.

If you could actually compete against fiber I feel like the funding would be very easy to acquire if your first step was linking up the various stock exchanges - those guys pay up the nose for even slight latency decreases.

This isn't going to be lower latency than existing low latency solutions.

EDIT: For more context, the old low latency fiber path between Chicago and New York was under 7ms, and current low latency radio solutions are under 4ms. SpaceX's solution is marketed as being "as low as 25ms".

It will matter for international trading, however.

No consumer will worry about latency or any other component of the physical feat of delivering internet via Starlink. Consumers are currently buying downstream bandwidth by the mbps from one or maybe two providers with no other options. Only technology oldheads who remember satphones and Hughesnet will worry, then research, then try it out for themselves. Starlink has the added benefit of being very easy to give a “consumer trial period.” It will sell itself, in the USA at least.

> No consumer will worry about latency

I think this would only be true if internet gamers weren't a thing, but they are, and they'll care.

competitive gamers make up a very small percentage of all internet users (or even gamers!). Like professional athletes, they will move or go to a special facility for this sort of latency requirement.

Many games are not as latency sensitive as you think - people used to play over modems!

Starcraft on my dial-up!

The latency is copper to your home. Dial ups are as fast as broandband but throughput low.

You might want to do some googling, that is absolutely not true for a few reasons that are not about throughput.

You forget about the decoding tone signals and telephone exchange load. Long distance calles have a very big latency for a reason.

If by "competitive" you mean anyone who plays any sort of real-time game such as RTS, FPS, or even real-time mobile game. Many consumers may take a while to figure out that latency is the reason they lose/die when it doesn't look like they should, but they will feel the effects immediately.

Granted users in rural areas are likely the most apt to benefit from this service and those users don't likely fantastic internet to begin with. However, if SpaceX markets this to areas with decent quality internet they're likely to get a bad reputation for "crappy" internet.

Yes, even those people make up a tiny fraction of the internet. Satellite internet typically will not work for those people, and there is no point in trying to sell to them.

Kids who play Fortnite are absolutely not “a tiny fraction of the Internet”.

Kids who play fortnite don't have any decision authority when it comes to whether or not to use cable or satellite.

Ehhh, not sure about this. If you're a parent and your kid is begging you to get faster internet, you might listen to them a little bit. If their marketing can get those kids to do that, then that might be a successful campaign.

I agree in principle that kids can influence parental purchasing, and that marketing is geared to take advantage of that. But the effect appears to be most effective for items that are exciting and tangible objects in front of the child; think checkout aisle candy, not “boring” adult things like finance and bills.

Here’s an interesting parallel; how much say does any child have in the cell phone plan that a family uses? Probably damn close to 0. That’s a decision that the parents make on their own, and dictate the rules of usage to their children. I suspect that internet service will remain that way as well.

The huge amounts of marketing aimed at kids would suggest kids on average have a lot of influence on decisions in their household

For candy and toys, sure. But there are a wide range of goods and services where the child has 0 say. Cars, homes, and even cell phone companies never market to kids in order to influence the parents, implying that children have no meaningful impact in these areas.

Now these services advertise to adults with children, such as being able to call your kids whenever with the unlimited cell phone plan, but that’s still advertising to the adult, not the child.

Sample of things kids who play Fortnite have (indirect) decision authority on:

fortnite v-bucks default gift for birthdays, displacing the movie gift cards

racking up hundreds of dollars worth of v-bucks per year

getting family to buy a Samsumg S10+ so they can reap the associated "skin" to their Fortnite account

graphics cards upgrades

(expensive) gaming mice and other gear pushed by youtubers

general merch like toys

2.4% of internet users play fortnite. Is that a large percentage to you?

That's the same percentage as Linux users, and just yesterday I closed my Box.com membership because the don't have a Linux client "due to low demand".

It pretty much is imho because it's just this one game and there are more.

People outside the western world still very much use internet cafeś / game cafes to play games on decent hardware and with a good connection.

I play League of Legends and have only DSL but my ping is only 35 ms and I can't complain -- many other players have it worse than me.

What did make it impossible for me to get kills was having 30 ms of latency in my display system. I think the network latency is well-compensated (if the typical user has 50 ms of latency, just delay me by 20 ms) but the display latency kills me. When I switched to a different monitor I started playing much better in about five games.

I think the game generates a 10 MB log for a 30 minute session so the bandwidth requirement is not much.

I had the same experience playing Titanfall earlier; in that case turning on the "Game Mode" on the TV turned me from someone who couldn't win at all to somebody who could get halfway up the ladder.

Display (and input!) latency are real things, and matter quite a bit. There have been studies in the past where people measured the full button press to frame update time using high speed cameras, and not all games are equal. As for game mode on TV's, that specifically why it exists. As a passive medium a little latency doesn't matter, but when a system is responding to input, latency is noticeable.

If you're interested in how different TV's perform, segregated by their individual input ports (in cases where some ports are optimized) and modes, check out https://www.rtings.com/. I used it a couple years ago to pick out a good 4k TV as a monitor, and the very thorough information helped me pick out something that works well as a computer monitor (and also for the occasional gaming).

This is a legit question.

How does 30ms of display latency affect LoL gameplay? I don't play it, but I've seen videos of it a few times and with it not being a FPS I wonder what aspects of the game are that greatly affected with an additional 30ms of display latency.

Mind you, any mouse lag drives me up the wall. I've never measured at what point I perceive that mouse lag, but it's a fairly low number I'm sure.

If the latency is 700ms you can’t even have a decent Skype call.

Try having an RDP session to fix Windows servers based in Australia with 400+ ms latency (Europe is unfortunately nowhere near Australia) on your GUI, the ordeal will leave a permanent scar on your psyche.

The speed of light is insignificant for such a short distance. Even if the signal travels as much as the circumference (40000km) of the earth at 70% lightspeed it shouldn't take more than 180ms. The lowest possible latency between Australia and Europe would be 60ms. Congested networks and network routers with suboptimal routes introduce far more latency than the distance. I regularly get between 100ms - 200ms latency between California and Germany and the latter number includes the realtime encoding/decoding of the video stream.

I've found RDP to be infinitely better for shitty networks than say VNC, if that's the other option.

I guess it depends on the game being played. When I played C&C in the 90s over modem, the latency was huge but it wasn't a major concern for that type of game.

Now that I play real time sports, and I'm no professional, it still makes a big difference in my enjoyment of the game when I'm playing at home with ethernet and top tier internet service vs playing at my parent's house on wifi and basic internet. The lag can really affect my ability to play my best and it sucks losing because you don't have a low latency connection.

That said, I'm very curious to see what the latency will be, because if it's within a reasonable range it could be acceptable. Either way, I don't think even casual gamers will have a significant impact on their sales, but it will have some if the lag is too great for some of today's games.

I’m just pointing out that the slice of consumers who are a) internet gamers b) concerned about Starlink latency and c) still think Starlink is old school geosynchronous satellite. Gamers will of course worry about latency just like they optimize every other aspect of their setup, but not to the effect that SpaceX needs to mount a marketing campaign to that effect.

That's a pretty small market and definitely not the target of this technology.

With the right type of architecture, low-earth satellite could offer better latency than terrestrial.

terrestrial internet goes through optic fiber in which the speed of light is maybe half the speed of light in a vacuum. Already HFTs use microwave links to shave off a few milliseconds between New York and Chicago. From Boston to Seattle the extra 600 miles up and down from the constellation would be overcome by the fast path along that route.

Note that requires switching from one satellite to the next, not the "bent pipe" architecture to your local rent seeking wireless company that StarLink and other LEO constellations plan.

Terrestrial microwave has almost the same speed as light in a vacuum, so I think it's possible a microwave network beats Starlink.

Remember each ~25 km you'd need a relay after you hit the horizon. That adds non-zero latency vs a longer-range-through-vacuum transmission.

25 km is less than typical, but remember each direct LEO path between popular destinstions is likely to be congested.

I’ve read the paper that started this idea of Starlink being a low latency alternative for hft (http://nrg.cs.ucl.ac.uk/mjh/starlink-draft.pdf) There are a couple of problems with the paper. The first is that they establish a range of acceptable latency as existing between the great circle route and the fastest ping time on the internet between two points. For example they found that NY to London was 75ms round trip on the internet. However the long time standard bearer for a pure fiber path had been 64ms until the latest gen cables arrived in 2016. At that point the latency was sub 60 ... very comparable to the 55ms great circle route. But it’s important to understand that the starlink point to point route will be constantly changing — so only in one or two instances will that latency even come close to the existing terrestrial routes. More often than not the latency would trend closer to the 70ms range - well beyond anything considered competitive either in the current generation of routes much less the prior generation. It’s as if the authors simply had no idea about the hft market and what latencies might be needed (all of which has been published publicly). But there’s another problem with the study. For the solution to work, spacex would need to dedicate one of its laser links to enable communications across other satellites and dedicate that capacity to this application. And further, the study did not address the issue of optronic delays within the satellites. Most microwave manufacturers care little about hft latency tolerances and intermachine delays can be 1-2ms per hop. Assuming starlink to not to be much different (although I don’t know this to be true or not) that would definitely add even more latency to the equation. So all in all while it’s interesting and will do amazing things for consumers and enterprises, I don’t see starlink being a competitive hft solution unless the route in questions is really long and a lot of other engineering stuff can be made to work to enable it. Call me a skeptic but I don’t think we will see it.

> terrestrial internet goes through optic fiber in which the speed of light is maybe half the speed of light in a vacuum.

What's your source for this? According to my quick search, it's typically 0.66c - 0.76c while researches have reached 0.99c.

Yeah, and they'll care enough to actually find out what the latency is rather than reflexively shooting things down. And don't forget word of mouth. All it takes is one prominent streamer that you follow, or anyone in your friend group, saying good things about it -- and now it's on the table for you.

Internet gamers are fine with double-digit millisecond latencies, and this is what Starlink will offer. It takes less than 4ms to reach 1000km LEO orbit, so 16ms for the full round-trip (you -> sat, sat -> server, server -> sat, sat -> you). Make it 2ms ground-to-satellite and 8ms round-trip if you believe the model from this thread[0] (satellites at ~600km). Using its numbers, add 2x 2ms for each inter-satellite link you have to travel back and forth.

It still adds up to sub-100ms latencies. It ain't bad.

[0] - https://www.reddit.com/r/Starlink/comments/9wrkhm/starlink_l...

What do you mean remember HughesNet? People are still on it. Some of those people are young. All of them have been taught what latency is by having satellite internet.

There are plenty of non-technical consumers who have had a very unwilling education in what latency is and how it differs from speed.

You are correct, it’s more prevalent than I realized, but those people will most likely welcome Starlink with wide open arms.

Starlink (and other similar systems that are hopeful to launch) are the real competitive threat that Google Fiber only partially lived up to being.

It threatens the existing entrenched providers everywhere. They can't hide from it. They will have no choice but to respond. They face a scenario losing tens of millions of access customers over time to this approach. And the existing options are priced so high in the US, it provides a big fat margin opportunity for Starlink & Co. to target (and ride for the benefit of paying for the buildout).

We had to go to space to route around the cable oligopoly, beyond their local crony jurisdictions.

Nope, Starlink would be crushed by tens of millions of customers (mostly concentrated in major metro areas) in the US and those customers would switch right back to cable. The capacity isn't there.

Can you show me the definitive proof that Starlink (along with its competitors, who will plausibly also launch a vast number of satellites) can't support eg 20 million customers in the US over time? I'd be very interested in that demonstration of the limits on the market.

Also can you support the premise that their customers would be concentrated in major metros, when the biggest beneficiaries will be outside of metros where broadband options are drastically worse (which is why the primary market for HughesNet the past two decades has not been concentrated in major metros).

Access providers in metros can soundly compete with Starlink. They'll lower prices, increase speeds, improve bundles, etc. Their infrastructure and customers are already in place there, they won't just ignore Starlink, they'll compete. That heavily limits the upside potential for the Starlink concept in metros. It's everwhere else, mostly lacking any real broadband, that Starlink & Co will face minimal competition and will particularly lure customers. It's why HughesNet still has over a million customers today.

I've seen a lot of people claim - with very little supporting evidence thus far - that the market is extremely limited due to capacity restraint.

While you're proving out your claim, if you don't mind given that you've got a strong handle on the market ceiling, please provide what you believe to be the maximum subscriber potential for Starlink - and the approach in general - in the US over time.

I think Starlink is for rural customers and can't compete with decent wired broadband. You were the one who seems to be putting it against cable (which exists in the metros, not in rural areas).

The MIT work linked in this thread calculates a total worldwide capacity in the ~20 Tbps range for Starlink.

I didn't see the link, but here's the presentation[0] I believe you're referring to. It estimates Starlink's max total system forward capacity at 23.7 Tbps.

0. http://www.mit.edu/~portillo/files/Comparison-LEO-IAC-2018-s...

EDIT: Sounds like this site's measurements for satellite internet are incorrect. Maybe HughesNet partners with fiber providers in some areas and therefore brings average speed down.

We could use objective reporting of internet speeds in finer detail. Any ideas?

Original comment:

--HughesNet's average latency is now 62ms, 58 ms jitter,--

https://broadbandnow.com/HughesNet-speed-test

--That's quite reasonable.--

That is incorrect. Round trip is still 20k+ miles that is ping to ground station before it's sent to one of the sats. It will still be 600ms+

That's unfortunate. Looks like we don't have an objective measurement of satellite internet speeds, then.

Sure we do, we have the laws of physics. HughesNet has geostationary satellites. They orbit at ~22,200 miles up. Assuming speed of light, it's going to take ~120ms per hop. There's a minimum of 4 hops (you -> satellite -> ground station -> satellite -> you), or 480ms.

And that's assuming perfect conditions and ignoring the rest of the normal latency encountered online. It's physically impossible to have a latency lower than ~480ms with geostationary satellites.

Color me skeptical that Starlink will reach its theoretical maximum capabilities, or that it is competitive with 5G. I'm fine with fiber until then. It's affordable in most of the world. The problem of broadband monopolies in the US is not going to be resolved by a new privately-owned technology. We should hold local politicians' feet to the fire, not throw money at new tech from a monorail salesman.

>> We should hold local politicians' feet to the fire, not throw money at new tech from a monorail salesman.

We need to do both, as Seattle has proven with its sporadic availability of gigabit fiber and the shutdown of third parties attempting to bring it here.

In fact, doing the latter IS doing the former.

Centurylink covers 70÷% of the city with gigabit for $65 a month, take a look at the cable franchise map before throwing stones: http://www.seattle.gov/tech/services/cable-service/cable-fra...

Yeah, I happen to live in an area that CL offers 6mbps maximum to, and it is weirdly in a minority-dense part of Seattle metropolitan. They have zero plans to expand to our area, they've stated repeatedly.

I'll throw stones as much as I like, thanks.

The city contract requires they service the lowest income parts of the city first, hence the extremely patchwork rollout over the last few years.

Due to the mandatory client base skew, the city is causing them to redline middle and high income areas of the city. Fiber is in Georgetown and Rainer Valley, but your SoL in Fremont's built up areas and in Sand Point.

Universal coverage should have been mandated, but its easy to end up like Kenmore (which required total Fios coverage from Verizon, now Frontier) and has seen Finn Hill go unserviced for years. Enforcement of the franchise contract is just as critical as initial negotiation.

Outside of a few select areas, most of Seattle only ever saw ADSL (or no DSL in parts of the north end) as we didn't allow large VDSL2 cabinets in the public ROW. I think this has caused Centurylink to build fiber in the city, as they've rarely overbuilt VDSL2 areas like Bellevue, Kent & Auburn.

>> Rainer Valley

Nope. I live square in the middle of it, can't get double digit mbps download speeds from them.

I would encourage you tp double check during the daytime on https://shop.centurylink.com/MasterWebPortal/freeRange/shop/...

I've noticed they seem to offer ADSL (6mbps) after 6pm or so at addresses that already have fiber, presumably their prequal database for fiber goes offline for a few hours a day.

I've called multiple times and schedule a check every three months to see if it's been updated. Been doing that for years. Won't give you my cross streets but I assure you, they have nothing for me.

They say it's available just a few blocks over. That's been the case for a long time and they can't seem to get it about 0.25 miles further. Been that way for years.

> it's affordable in most of the world

I'm afraid you are drastically underestimating how much it actually costs to install fiber.

Good point. I meant the developed world.

Regarding the 3rd world, Facebook offered India free internet with strings attached, and IIRC they rejected it. That idea wasn't too popular there or here.

Would Musk be given a pass for offering discounted or free internet to 3rd world countries, and what strings would investors suggest he attach?

> Would Musk be given a pass for offering discounted or free internet to 3rd world countries, and what strings would investors suggest he attach?

Why would he want to do that? Facebook wanted to do that, because that would drive more users to their platform. SpaceX wants to use Starlink in order to bankroll BFR[0], so what they want is to simply sell the service at a price point that generates them enough money. It's not beneficial to them to discount it, make it free, or play other shenanigans.

[0] - Or whatever it's called now; it'll always be the BFR in my heart.

> Why would he want to do that?

Because granting internet fast lanes to certain content providers is a way to generate revenue.

Zero-rating is already happening [1].

[1] https://en.wikipedia.org/wiki/Zero-rating

If you have a lot of market power and you want to make as much money as possible the rational thing to do is to charge people according to their willingness to pay[1]. You can't do this perfectly but this is what is behind senior discounts and Intel's huge number of SKUs. Since people in Botswana can't profitably resell their internet in England, since Starlink can easily charge different amounts in different countries, and because the marginal cost of servicing a new region is approximately zero it would be crazy for Starlink not to do geographic pricing tiers.

[1]https://en.wikipedia.org/wiki/Price_discrimination

That sounds like a yes.

If money is your only goal, that's completely rational. However, that's not how I've typically heard people champion Musk. He's been lauded as a progressive person whose aims are meant to serve humanity, not merely his wallet. Supposedly.

It's not like serving humanity and making money is mutally exclusive. If there are markets in developing countries he can serve cheaper than anyone else both sides profit: he makes money, the people get cheaper internet.

That said, internet already tends to be the infrastructure demand best satisfied in developing countries. Building cell phone towers is much easier than building roads, and with cheap labor and no purchasing power comes cheap internet.

> If there are markets in developing countries he can serve cheaper than anyone else both sides profit: he makes money, the people get cheaper internet.

Let's see whether it is net-neutral internet or not, then judge. My guess is it will have exclusive offers to content distributors in order to lower cost.

All human beings are complex and you can't just sort them into good people and bad people. Elon seems to be more idealist than most about the fate of humanity as a whole but also seems to be willing to work his employees to the bone, drive sharp bargains, etc to pursue that goal. He's said that he sees Starlink as a cash cow that'll fund future Mars colonies and I don't have any reason to believe that he isn't being sincere about that.

> All human beings are complex and you can't just sort them into good people and bad people.

Some would make the argument that if everyone worked with only their wallet in mind, we'd be better off. I wouldn't.

> Elon seems to be more idealist than most

Elon is not an idealistic engineer, he is a businessman. He actively misleads about products he must have been told will not meet the timelines he promotes.

> about the fate of humanity

Not sure where you get this idea. The way he talks about AGI taking over the world is creepy. He thinks it's inevitable, nevermind that we have no idea how to design anything close to AGI.

>Good point. I meant the developed world.

I think your parent also meant the developed world.

In devloping countries it's sometimes much easier to get fibre. No or very little infrastructure means no old copper wires lying around. You can go fibre instantly this way.

It’s cheap to get fiber in developing countries because labor costs are extremely low and government regulation is lax.

Australia would like to argue this point, but the latency of our replies would make it seem like they're coming from the late 1990s.

Who's the "we" that is throwing money at this? Starlink is privately funded.

Fiber is affordable in cities (a market nearly impossible to service by satellite anyways). Even developed countries struggle with deploying fiber in rural environments.

Every satellite internet offering targets rural settings, ships and planes. StarLink is no different, just that they will be competitive in a wider range of such settings.

Why can't you avoid the ground station and just do satellite to satellite for relay? I believe that's precisely how starlink works.

In GP's post the second satellite is the same satellite, just on the way back. The post assumes for demonstration that the ground station is the destination.

You're pinging a device on the ground

  t=0 You send out ICMP request
  t=120ms it hits the satelite
  t=240ms it arrives at the ground station, ICMP reply occurs
  t=360ms hits satelite
  t=480ms arrives back at the originating machine

The only way doing satelite-satelite at a GEO level would be useful would be

1) You're pinging a device on satellite in GEO (one you don't have LOS to)

2) You're pinging a device that's also connected via a different GEO 120 degrees away from the first

in this case you'll

  t=0 You send out ICMP request
  t=120ms it hits the satelite
  t=240ms it arrives at the ground station 1
  t=280ms arrives at ground station 2
  t=400ms hits satelite #2
  t=520ms arrives back at the destination
  t=640ms response arrives at sat #2
  t=800ms response arrives at ground station 2
  t=840ms response arrives at GS#1
  t=960ms response arrives at sat #1
  t=1080ms response arrives back at originating machine

You could change that, but you won't save much in GEO as you're connecting to two different satelites, 120 degrees apart or 70,000km (235ms)

  t=0 You send out ICMP request
  t=120ms it hits the satelite
  t=355ms hits satelite #2
  t=475ms arrives at destination
  t=595ms response arrives at sat #2
  t=830ms response arrives at sat #1
  t=950ms response arrives back at originating machine

Reality of course is that typical satelite latency is 800ms or more (depending how much you pay to skip buffering) rather than 480ms.

I was going to ask, "Didn't HughesNet try this?" .. I didn't realize they were still around, although it does make sense for a lot of rural areas with limited broadband options.

Or RVs. Even chain stores use the service: easier to manage 1 big Hughes subscription instead of 500 or 5000 different local ISP contracts, each with their own quirks.

LTE may have put a dent in that model though.

LTE hasn’t made as much of a replacement in Home Broadband in rural as much as you’d think largely due to tower congestion. Cell site density is so low — plus deprioritization at 30/50gb.

In addition you’ve usually got only 1-2 networks in deep rural.

Source : I run an MVNO.

Customers of HughesNet know about latency but it's low on their list of concerns. The top three being data caps, price, and data caps.

> All of them have been taught what latency is by having satellite internet.

Yes, life is a great teacher.

HughesNet sends me a post card every quarter or so. Sure I live in the middle of nowhere and would seeming be likely to want it. What makes me laugh is even the old people in the area who you'd think wouldn't know how to use a computer will warn friends, neighbors and community not to use them. They may not know the term latency, but they know that the quality of calls are poor and they know uploading videos from their phones takes way too long.

I don't think you're allowing for the the temerity of terrestrial services. They will conflate the poor performance of legacy satellite systems with this system. They will exaggerate the latency deficit over short paths and allow people to think this is the general case. They will do this to leverage the preexisting perception of poor satellite service performance that so obviously prevails.

Only a solid marketing campaign can deal with this problem.

> Consumers are currently buying downstream bandwidth by the mbps from one or maybe two providers with no other options.

Isn't this going to improved with 5G? Verizon already has plans to offer 5G internet at homes in 10 cities by end of this year.

"in cities". there are a lot of people that don't live in major cities.

I would say there are a lot of people who live in cities/towns instead. You need the scale for things to work. I hightly doubt this project is only aiming at people not living in cities.

At some point Verizon and AT&T will get the service requirements relaxed so that 5g counts as servicing a home. At that point they’ll run through and service all of the old rural installations. Hopefully the rural power companies do the same with the fiber they run inside their steel lines. There’s my guess anyway.

There is a reason for this as there are a lot of customers in on place. Satellite based internet allows you to have your infrastructure where you need it, even this requires a close control of your orbits. And then question is whether satellite internet will be a) faster b) be more reliable and c) cheaper than ground based fibre and 5G. If yes it might give these two alternatives a hard time even in metropolitan areas. If not satellite based internet will only be interesting for rural areas. Not sure if the potential higher prices off-set the smaller customer base. And in developing countries higher prices are basically off the table anyway.

Satellites still are in space, so everything is more expensive up there, getting things up, repairing things, building things for space, operating things in space...

Another thing is jitter. By design flying satellites are going to create jitter, and even with good latency, it can be bad for stable video streaming, video calls, etc.

The jitter will be unlike regular jitter though.

The moving satellites will lead to the latency of all packets being the same, but vary over many minutes.

The bad jitter is the stuff that varies on a packet to packet basis.

No consumer will worry about latency or any other component of the physical feat of delivering internet via Starlink.

Gamers and nerds of various kinds will worry.

The article says 15ms. Even 2x that at 30ms or 4x is totally playable on most every game.

30ms round trip is very good. 60ms round trip is quite noticeable for expert players.

VOIP. 150 ms max recommended, noticeable degradation of UX at 250ms. Many phone operators use wifi to connect when they can. If people's phone does not work well, they'll complain.

To get better than 10mb down and 2mb up, I'd have to buy it from another country. Please let me be the first customer.

How can it be worse than literally all I can get?

>It will sell itself, in the USA at least.

Sorry for this shallow comment but I've read the title several times now, my mind races to the same thought:

>...to sell wireless high-speed internet from space!

"I wish them wild success, it's promising to see the opportunity for disruption of our telcom mafia as wireless comms tech evolves, but selling internet from space... total horseshit! Success or not, most space internet subscriptions will be sold from a call center in India." /s

That's true and bandwidth is actually something I've been wondering about: what kind of bandwidth can an inexpensive ground-based system get, reliably? Sending bits in a fiber is famously free of interference, while hundreds of miles of atmosphere is notoriously bad as a transmission medium. I haven't seen any kind of calculations around this. How many clients can hook up to one satellite concurrently, what kind of bandwidth will each get, realistically (theoretical max bandwidth is not so interesting). Without more information, my first thought has been that Star link sounds like an excellent, satellite-based internet technology ideal for connectivity in isolated places (far from urban areas, on ships and airplanes, etc) but which may not really be competitive for consumer internet access in urban areas. Hope I'm wrong.

The atmosphere shouldn’t be too much of a problem. It thins out very rapidly over a few km altitude, and the beam is going almost straight up. It’s nowhere near as bad as the same distance through the atmosphere at near ground level.

> what kind of bandwidth can an inexpensive ground-based system get, reliably?

Theoretically 56 Kbit, but practically closer to 40 Kbit. I'm being serious! Given the choice between hugely expensive and high latency satellite Internet and dial-up, many have opted for dial-up, even in this day and age! We're not even talking that far away from urban centers, either, especially in hilly areas. A couple hour's drive outside of San Francisco is enough to get to cell-phone network dead spots, never mind LTE. There are some hyper-regional wireless ISPs using 802.12-based gear (Uniquity), but those are the exception.

Given that, (which is so extreme that I'm sure that not everybody that reads this will even believe me), any competition to HughesNet will be very welcome. Prior to SpaceX, the cost of getting a constellation of satellites into orbit was prohibitively expensive, but with this being done by SpaceX, the launches for this will be done "at cost", (corporate accounting and cost centers notwithstanding). (Which, mind you, is still several million dollars per launch in rocket fuel.)

Hopefully that means a genuine competitor to HughesNet, but that's a low bar. There is a large initial investment (of time and money), but FCC approval is an important first step towards providing this service.

I think that the key competitive advantage is exactly how cheap it is to acquire new users. Anyone that is off the main grid can still get decent internet without signing up to a long term landline contract. This removes one of the big barriers to entry and changes the industry as a whole.

I am excited about the possibility and think it will (eventually) sell itself though word of mouth (how exactly do you advertise better Internet access to a market with poor Internet access? Billboards and USPS mailers?). I doubt most consumers have the background to know difference between latency and bandwidth, so hopefully this is price competitive with HughesNet!

Elon should really do a John Henry if he can afford to set it up. Run a head-to-head data-transmission with checksum validation in some theatrical setting. For bonus points he could (if it's possible) run a self-driving car demo where the computation is being done and relaid by a LEO uplink.

Also, I hear what you're saying but... Right now the Algorithmic traders all use fiber and new fiber is constantly being rolled out to support even lower latency connections so I'm skeptical - if it was competitive wouldn't G&S be using it to contact the London stock exchange? Or, is it that fiber can produce lower latency in idyllic scenarios but that congestion pushes the latency beyond that accomplishable by an LEO setup for us plebs?

I remember reading about line-of-sight microwave links being used for trading here on HN. I think line of sight is the key difference between fiber and radio.

Microwave, or even HF. Definitely using direct RF links though.

I dont know if I'd call it direct line of site, but low bandwidth directional microwave communication is definitely used over-the-horizon from say Chicago to London. This [1] Bloomberg article has a great rundown on microwave in finance.

Bandwidth is low, but latency beats fibre, and you can bounce microwave off the ionosphere between London and Chicago (and various other routes). This article doesn't mention the cross Atlantic transmissions, but it is possible, and does happen.

Disclosure: I have worked at several of the Chicago based firms mentioned in the linked Bloomberg article.

Edit: grammar, formatting.

I wasnt directly involved in any of the microwave networking, but ask me what you want and I'll answer to the best of my ability.

[1] https://www.bloomberg.com/news/features/2019-03-08/the-gazil...

More than you can possibly ever want to know about this subject here:

https://sniperinmahwah.wordpress.com/2014/09/22/hft-in-my-ba...

Serious algorithmic traders use point-to-point microwave links, because the speed of radio waves in air is about 50% faster than light in a glass fiber.

With a phased array could you link this through a LEO swarm to hit targets hidden beyond the horizon?

I'm super unfamiliar when it comes to this sort of hardware.

The majority of the latency improvment from these hft networks is because the path taken by them is more direct. Fiber routes follow roads and railroad tracks. The series of point to point antennas takes closer to a straight line.

As far as I'm aware, there aren't any LEO satellite internet providers at the moment (a few in GSO, but the latency there is probably too long to make it relevant for trading), so I think that it just isn't an option. It'll be interesting to see what happens when the first LEO constellations come online.

> if it was competitive, wouldn't G&S be using it to contact the London stock exchange?

They will, but no such satellite network currently exists. Right now, all of the satellite internet services are using satellites in high orbits. That means they can cover more of the Earth's surface per-satellite, and the satellites last a long time. This was necessary when rocket launches cost >$10,000/kg.

SpaceX is drastically lowering the prices of launching satellites ($1k-$2k/kg, Starship will probably be <$500/kg), and they are taking advantage of that by launching thousands of satellites into LEO (Low Earth Orbit). These satellites will have a 5-7 year service life, which will reduce the cost per satellite and allow for regular upgrades via replacement.

Newer hardware and lower altitudes means less latency and more bandwidth than previous satellites. It will definitely beat transatlantic fiber on latency, but bandwidth will be more limited.

Not everyone has realtime needs. If you're not voice chatting or playing realtime games it's not that bad.

Even in voice chat's case latency isn't a huge issue until you get really high numbers. But you're right, even higher latencies can fit the 80% or even the 90% use case.

A misconception probably due to an overestimation of how far away space really is; the ISS only orbits at roughly 240 +/- 30 miles, and the (admittedly arbitrary) boundary of space is at 60 mi (100 km).

The boundary of space varies depending on who you ask.

https://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line

The article implies more uncertainty than there is. To my knowledge everyone agrees to define the edge of space at 100km (about 62 miles), with the exception of the US where for historical reasons the edge of space is seen as 50 miles above sea level. There is no international agreement, but even though the line is arbitrary there is no huge variety of widely held opinions.

> So there is a cross over point where the latency of a LEO satellite system is actually superior despite the uplink/downlink path.

There is, but given the rise of the use of edge caching and edge compute for latency-sensitive applications, with edge locations located to optimize access to masses of users, that crossover is unlikely to be actually reached in many of the cases where latency is actually a concern, and Starlink is going to be stuck behind unless it is able to both get edge caching and edge compute on its satellites and get content/service providers to use it, and comsats aren't exactly optimal locations for that.

Latency is also much less important with highly cacheable content. At least, I can’t really think of examples to the contrary. My patience for loading pages browsing is many orders of magnitude higher than realtime uses. Bandwidth seems to dominate in this context.

Latency of multiple seconds, like you can see in some places around the world, is much more frustrating than the kind of latency discussed wrt Starlink.

The lack of a close edge node is kind of interesting, though, so i’m not trying to dismiss your comment in the least.

Edit: wording

>many important routes will have significantly lower latency than any feasible terrestrial system

Is that accounting for recent developments in hollow core fibers?

>"The researchers successfully demonstrated the first high-capacity, low-latency data transmission experiment performed using a hollow-core fibre. In this, they found that light propagated 31 per cent quicker than in a solid core fibre, increasing from 70 per cent of its full speed in a vacuum to 99.7 per cent. To put this in context, this means that data propagating in this fibre would arrived 1.54 microseconds/per km earlier that it would in an equivalent length of conventional solid fibre. Not only did the light almost travel at its fastest possible speed, but it did so with a very low loss of 3.5 dB per kilometre."

https://www.southampton.ac.uk/news/2013/04/speed-of-light-fi...

> Is that accounting for recent developments in hollow core fibers?

No, it doesn't.

You're citing a story from 2013. Has this seen deployment in the field? I haven't found any evidence of this. That makes me wonder what is missing in this story.

That story was the first ever measurement of light speed in a new fiber technology, so it was obviously still in the lab at that stage.

It is still really an emerging research field, here's something more up to date -

https://www.laserfocusworld.com/articles/print/volume-54/iss...

But you can purchase it these days -

https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=91...

Also, I would think that the first transatlantic cable of this stuff might be kept pretty exclusive, given the economic opportunity presented by pissing around on the stock exchange.

edit - here's some more recent press from the Southampton lot - https://www.ses.ac.uk/2019/04/03/fibre-optics/

Latency's not going to be a problem. What is going to be a problem is what nobody is talking about: LEO satellites move. This means the downlink antenna has to have motors and move too, or it has to be a phased array and be expensive.

That's the innovation this is taking advantage of -- the downlink antenna will be tiny and can be embedded.

This is a new market, not entering into an existing market.

I'm sorry but you are incorrect. You cannot innovate your way around the laws of physics. Do you want 5 Mbps from a LEOSAT? Fine, you need a pointable antenna. An Iridium-style omni antenna cannot accomplish this. The S/N ratio is simply too low.

Sorry, but there are no laws of physics preventing innovation in the antenna space.

I suggest you study information theory and antenna theory. What you are suggesting is theoretically impossible. If a satellite could paint the continent with a megawatt, it might work. But satellites transmit with tens of watts, which gets spread over a large geographic area. The ground antenna must be pointed for decent bandwidth, either physically (with motors) or virtually (phased array) to achieve the requisite S/N ratio.

This is correct. Basic antenna theory covers C/N and how it relates to antenna size. There's no magic allowed.

> What you are suggesting is theoretically impossible

But then...

> it might work

Are you an expert in this field? I'm guessing no based on this exchange...

Your deceptive edits are...deceptive. The “it might work” was preceded with a hypothetical condition and then followed with the real condition. It wasn't “its theoretically impossible but it might work”, but, “its theoretically impossible; if satellites could carry transmitters two orders of magnitude more powerful than they actually can, it might work.”

That's not what "theoretically impossible" means. You literally just described a scenario where what I said would be theoretically possible, based on your own understanding of the technology, which is decidedly incomplete.

You also didn't answer the question about your expertise, I'm assuming because your answer is, "No". Maybe leave the correcting of others to the actual experts...

> That's not what "theoretically impossible" means.

Sure it is, if the hypothetical is pointing out a constraint on the boundaries of theoretical impossibility (or, in theory, if the hypothetical is itself possible to describe but theoretically impossible because of physical limits, though that doesn't appear to be the case here; there might be a theoretical lower limit on the size of a transmitter of the require power output or the supporting power system, but in theory there is no limit to the size of a satellite except the bound at which it becomes the primary because it's larger than the thing it is supposed to orbit.)

> You also didn't answer the question about your expertise

A careful examination of the thread will find that no such question was previously raised. There are more than two people on HN, so just because you get a response that doesn't make the person responding necessarily the person to whom you were responding. HN shows comment authors handles in case you ever need to know to whom it is you are responding, which you might want to do before attacking them based on assumptions about their identity.

If you can't see how something can't both be theoretically possible and impossible at the same time, we have nothing more to discuss.

If getting paid to design ground stations for LEO satellite constellations counts as expertise, then yes, I'm an expert in this field.

It will not be tiny, but they are designing a pizza box sized phased array antenna with a target price of $100-300.

> phased array and be expensive

There isn't any question about the type of antenna. The details have been filed with the FCC. The antenna will be phased array.

Obviously there is a high front loaded capital cost to developing a phased array transceiver for this system. The scale of the market, however, is vast; hundreds of millions of units. I believe the per unit cost of manufacturing these transceivers will be low due to this scale.

I can't know that however, so we'll have to wait and see.

Thanks. I suspected it would be PA, but I have not read the filing.

Why hundreds of millions? At most this service will have a couple million people on the entire constellation if you want the speeds musk is saying. Otherwise, you have much lower speeds and cram more people, which is a trade-off all satellite technology has.

We can't compute credible figures at this point because a lot of the technical information is proprietary and the business model isn't known. I don't believe Elon has committed to any specific bandwidth; searching yields claims of "up to" 1 Gbps.

Given the rates cited here[1] (20 Gbps/satellite) I seriously doubt that 1 Gbps is going to be offered at a price level that allows it to be widespread. More likely we'll see service offered in the 10s of Mbps.

So the best we may achieve is some napkin level estimates. Let us assume 100 Mbps as a realistic subscriber rate. 12000 satellites[2] * 20 Gbps/satellite * 100/1 over-subscription (typical, see here[2]) / 100 Mbps = 240 million theoretical subscribers.

Obviously every figure here is open to endless dispute, but we're in the right order of magnitude. I believe this is the scale Elon is thinking at; he's trying to fund interplanetary space travel with this. In any case there will need to be a couple mountains worth of transceivers for the plan to work, and making fixed function electronics at that scale is typically highly cost effective.

[1] https://www.reddit.com/r/Starlink/comments/7xzkl5/starlink_s...

[2] https://en.wikipedia.org/wiki/Starlink_(satellite_constellat...

[3] http://www.ctcnet.us/wp-content/uploads/2014/02/CTC-Connecti... "Cable modem and DSL providers often have a 100:1 or greater oversubscription ratio for residential users and a 50:1 ratio for business users."

I'm on a small island in the Pacific. If I can get 100 Mbps, by any means, whatever the latency, it will competitive. Right now I pay for 25, the two ISPs on island swear they're building out to 50, and I average 15 down and 1.3 up. my latency sits around 250-300 ms to North America and 150-250 to Asia.

Your math left out the biggest factor, which is useable bandwidth. Most satellites will be over water at any given time, so the number of users will be far less. Any you're talking about full build out, which is a decade away. Internet consumption has been growing nearly exponentially.

That's a great point. Figure 80% of the Earth is ocean, 240e6 * 0.2 = 48 million subscribers. Still large enough to justify, for instance, the custom ASICs necessary to achieve a low cost phased array.

Elon has previously said they are targeting $100-300 for a pizza box sized antenna.

Latency does not worry me, but the economics do.

An LEO satellite constellation has a bad urban/rural problem because most of the Earth's surface is ocean, uninhabited or uninhabitable. In the meantime, people from New York City and Detroit who hate their cable company will compete for network resources for people in the middle.

To take advantage of those thousands of satellites, subscribers will need to install high-performance phased array antennas that will probably cost at least $6000. There will be the capital costs for the space segment, also since the system is just a bent pipe to Verizon, AT&T or whoever your local rent-seeker is, they will take a cut.

Thus it is likely to be a very expensive service.

Any source on needing a $6,000 antenna to get spaceX internet? That would be a deal killer but haven't heard that.

Why do you think people who live in cities will want satellite internet?

Because they hate the cable company, because some of them have outrageous amounts of money, because some of them would like to have a backup connection, and because they are crammed in tight so even if the takeup is only 1% they still will consume a lot.

Isn't a lot of demand good for the economincs of this service?

> will probably cost at least $6000

What is your source for that figure?

If it's military/aviation/naval phased array radar this is a very different use case. The targets are transceiving from well known locations, not maneuvering to reduce signature. The orbiting target is well above the horizon, not hidden in clutter. There are well defined frequency bands so high frequency agility is not necessary. There are no purpose built enemy jammers to overcome so extraordinary power levels or heroic filters aren't necessary. There are no afterburners or naval catapults to withstand.

About the worse case I know of with the bands involved in this system is rain fade or snow cover.

We already have MIMO beamforming transceivers at nearly disposable prices in the form of wifi routers. I think it's entirely feasible to develop a fixed function civilian phased array at a reasonable cost.

Anyhow, with any luck we'll know soon.

> at least $6000

SpaceX is working on making a low-cost phased-array antenna the size of a pizza box, targeting $100-300.

Direct source is a presentation Elon Musk made in 2015, video linked in this faq: https://www.reddit.com/r/Starlink/comments/ayec7p/starlink_f...

I just spent half an hour searching for that too...

Transcript for those who prefer text: https://web.archive.org/web/20150329174815/http://shitelonsa...

Cool idea, but sounds a lot like your typical Elon announcement. SpaceX ia doing great in the rocket business sue to clear advantage regarding development costs (I still have my doubts regarding their true launch costs, so). Pushing them to develop new antennas shifts the focus, not sure if that is such a good idea...

I feel like a majority of people falsely think the cell phone in their pocket talks to satellites anyway. So a space delivered ISP might not be a big shock for people.

As someone who has run a tiny ISP in a tiny town, I assure you “people” are much more knowledgeable than you assume. I was actually able to disable all monitoring systems, since I would get a phone call, immediately following any event that caused high latency, or any kind of internet disturbance. I learned that people who live in smaller rural towns are in some way much more dependent on the internet to provide things like entertainment, news, info, media, since there are fewer social events, theaters (etc, etc).

> "I would get a phone call, immediately following any event that caused high latency"

Also at like 04:00 in the morning? :- )

Probably means someone thinks your service is shoddy and they set up their own monitoring.

> fiber isn't latency free. It isn't even speed of light. It's about 70% SOL.

There's use cases (high-frequency trading) where maintaining faster-than-fiver microwave links makes a lot of sense.

https://arstechnica.com/information-technology/2016/11/priva...

It will only take a few real customers talking about the latency being fine to make this a non-issue. It's very easy for people to test on their own. I doubt they'll have to do much specific marketing about this issue.

Why do you think that satellite to satellite routing will be particularly fast? There are a lot of hops, some satellites are moving relative to one another, and the satellites are power and bandwidth constrained. It sounds like a latency nightmare.

Consumer connections will use bent pipes. Satellite to satellite links are limited and will be mostly used by high paying customers like high frequency traders.

I wonder if this is a temporary software design problem. I mean, we have response time to burn these days, so we design with that in mind. If latency became a fact of life due to demand for a better deal on Internet access, maybe people will figure out how to make software that doesn't depend so much on a tight server loop.

Given that speed of light is ~3×10⁸ m/s an additional ~1,000 km (10⁶ m) up and down and back again would increase latency on the order of ~10 ms (10⁻² s).

~10 ms of additional latency isn’t wildly out-of-sync with real world latencies of ~40 ms within North America and ~70 ms across the Atlantic. [1] And if we factor in the ~30% reduction of speed of light in fiber, the delta might actually be less than ~10 ms.

[1]: https://enterprise.verizon.com/terms/latency/

Most people think their cell phone signals go to space.

>many important routes will have significantly lower latency than any feasible terrestrial system.

Neutrinos brah.

Sorry no offence but why is this even a conversation? I use Hughes which is geostationary. 600 to 900ms latency. That is around 35000 km altitude. These will be hundreds of km altitude. Kinda basic math to get the answer here.

And Ground infrastructure doesn’t exactly take a straight path either. Add 5-10% slack in the line for loops/splice trays/pole movement, and then going around artificial and natural barriers...

When AWS introduced Ground Station [0] I was unsure as to their motivation. Looking back on it, this kind of endeavour might have been the impetus for the service. In fact, given how much of the "Internet" depends on AWS, SpaceX using Ground Station might actually lower latency to your favorite website.

[0] https://aws.amazon.com/ground-station/

I don't know about the LEO numbers but quick back of the envelop calculation assuming 1000 km means this latency would be nearly 3 ms.

Honestly I will be fine with bad latency if I can get reliable wireless internet anywhere on earth. If I need good latency, like for playing games, I will go to a location with fiber.

I really, really think SpaceX Internet can do a lot of good. It may force competition. It may give internet access to many countries where it's not an option. It may even help fight censorship, or open the door to an alternative to the current internet network.

Lots of potential.

Reminds me of the story recently which mentioned Grace Hopper and her famous visual representation of how far information could travel in a nanosecond when answering a question about why satellite communications takes so long.

Local latency might be okay (worse then fiber, slightly worse than cable) but using space based routing is going to be a poor experience. There are a lot of latency-adding hops in space, and the terrestrial link bandwidth is so poor that popular destinations (LA or NYC) are going to be congested at their terminal endpoints, meaning you'll go the long way around and exit the satellites at a farther, more rural base station than is ideal, and use fiber for the final hops.

LEO vs. GEO networks are like plutonium bombs vs. uranium bombs.

One is simple to engineer, but resources are limited and expensive. The other is extremely complicated to engineer, but resources are cheaper and more available.

In this case GEO systems are simple: satellite is stationary (ignoring slight drift which causes microsecond changes in latency), beams are stationary, antennas on people's roofs have no moving parts. However, the GEO satellite is extremely expensive, the spectrum it is using is expensive, and the GEO orbital slot is expensive. Also, it's so far away that it's high latency making online gaming nonviable.

LEO systems are extremely complex by comparison: satellites are moving, thus the beams are moving, antennas are moving (motor driven, unless using electronic phased array which are currently super expensive). With everything moving you have to do constant beam hand offs, doppler correction, etc. But, the satellites are much cheaper and the latency is much smaller.

Kudos to whomever can pull it off - there are several contenders other than SpaceX like OneWeb.

I believe the plan is for phased arrays, at both ends, at substantially lower prices than are currently commercially available.

Since SpaceX has already built the "first batch" of satellites (delivered to launch site as of a few days ago), one has to imagine they've largely solved the manufacturing problem and reduced the cost from 250k per antenna.

IIRC, OneWeb's initial plan was to use phased arrays as well, but it proved too expensive and they switched to mechanically steered antennas (at least for first gen).

Phased array is definitely the way to go if you can get cost down. No moving parts means fewer hardware/mechanical failures and less noise

What is the difference between phased array and MIMO? Isn't MIMO a solved problem and shouldn't the technology be transferable to this use case?

A difference is that phased arrays need sub-wavelength tolerances in phase between emitters to work

I can easily imagine economies of scale in MMICs (Monolithic Microwave Integrated Circuits) bringing the price down enough to make phased arrays affordable. I sincerely hope it happens.

Why are electronic phased arrays so expensive? I am no radio expert, but it seems that the pricey bit might be the engineering required rather than cost of production. From what I remember of my polar calculus, it sounds like a lot of painful calculus written once and fed henceforth into a computer.

Presumably you need a high-end FPGA or a custom VLSI chip to process the signals.

Both of these are very expensive in low-volume.

It also needs to be rad-hard for space. Terrestrial FPGAs are subject to occasional "SEU" (single event upsets)[1] which can arbitrarily affect behavior because gates can flip. Robust terrestrial FPGA systems have to handle SEUs; you have to imagine that these events are more frequent in space and need to at least be handled.

(This may something you already had in mind, summarized as "high-end FPGAs;" I just wanted to add some interesting color some folks might not be aware of.)

[1]: https://en.wikipedia.org/wiki/Single_event_upset

Good to know, thanks. I suppose at the scale of SpaceX, ASICs may be an option.

I'm not sure 4000 is enough to break even on ASICs, but I'll admit I don't know much about the costs of either high end FPGAs nor ASIC production at quantity 4000.

From what I am reading here, a large part of the cost is up-front with chip design and setup. I suppose it depends on pricing. They also may wish to sell more after those four thousand units.

http://blog.zorinaq.com/asic-development-costs-are-lower-tha...

Ground station cost is actually more of a concern than satellite cost, from market analysis I've heard. Going to need more of them.

In LEO it doesn't need to be rad hardended, especially for something that isn't life critical (compared to say, the control system of a space shuttle). At this altitude, the atmosphere and magnetic field provides a lot of protection still.

At the very least SpaceX would test the devices to see what effects the higher radiation would have. However it's not unreasonable to just have the software detect and reset itself, if a high energy event is detected. There are going to be a lot of these satellites and a lot of redundancy in coverage, so if one is down for a few minutes it's not that big of a deal.

Yes, as long as radiation only causes upsets and not permanent failures — satellites are somewhat expensive — and as long as software can detect faults and reset.

4000 satellites is enough to hit economies of scale. Per piece they are probably among the cheapest satellites in orbit.

Sure, but that isn't saying an awful lot; most satellites are very expensive. SpaceX would want to weigh the cost of hardening the system against radiation versus the cost of another launch to replace failure(s). I'd guess radiation-hardening of some kind (at least sufficient to prevent most permanent damage) would win out in that calculation, but I'll happily admit I don't have any particular factual basis for that guess.

You do not need a high-end FPGA; you need a bunch of small antennas (potentially extremely cheap, as these kinds of antennas are often microstrip antennae etched into PCBs), and a bunch of microwave-rated components such as mixers, phase-shifters and capacitors. The phase shifters allow you to add up the signals in such a way as to form a coherent beam in a certain direction, this is known as beamforming [0], and with some admittedly complex precalculation, an electronically-steerable antenna array needs nothing more than a simple microcontroller to set the phase shifters for the desired array orientation. Of course you would want to adaptively steer it based on received signal, but this can be done without the need for fancy FPGAs; your receiver signal chain will include all the mixers, demodulators and signal processing elements needed already baked in silicon; similar to how a WiFi chipset does channel adaptation by analyzing the received signal without resorting to high-end hardware, the kind of system that SpaceX is building does not require particularly exotic hardware (although it would be custom, and expensive to develop).

Speaking of which, there's a neat project that sneaks into a particular Intel chipset and extracts the CSI (Channel State Information) from the wifi hardware so you can actually do things like estimate which frequencies are being attenuated [1]. It's out of date, but still shows the kind of live, complex, signal analysis that is possible with commodity-priced hardware.

In short, I think it is certain that a base station can be built for <$1000, and likely that it can be built for <$150, although without knowing the precise specifications, it's hard to say. We did a case study on this in my antennas course in grad school 3-4 years ago, and our ending numbers on our prototype designs (not fully built and tested, of course, but simulated and spec'ed out with real-world pricing) were around $150. I am certain that our design as it was would not work, but something similar to it likely would. ;)

[0] https://en.wikipedia.org/wiki/Beamforming [1] https://dhalperi.github.io/linux-80211n-csitool/

$1000 won't recoup the cost of their constellation, so they better hope you're way off.

That's the build cost, which needs to be as low as possible. The cost charged to customers is a different issue.

The microwave devices are the expensive part. The signal processing and software are straightforward with modern components like DSPs and FPGAs.

Are hand-offs really all that complicated? Cell networks have to handle it.

I don't think you need to move the antenna, but you need a wide footprint and probably overlapping coverage between satellites.

How does Iridium work? I'd think this has already been done(quite a while back even).

LEO satellite handoff is tough because you effectively need two antennas: One points at the "old" satellite while one points at the "new" one. You can achieve this with a single phased array antenna divided in half and controlled by software, but each half must still be large enough to give the needed S/N ratio.

Iridium uses an omnidirectional antenna which is fine if all you want is 1200bps. But if you want 5Mbps, you have to point the antenna. So Iridium is not applicable here.

Cell hand-offs don't happen nearly as frequently as they would for an LEO constellation.

The orbital period for a satellite at 550 km is ~01h 36m. That means any given satellite is going to be visible for a very short period of time, which means hand-offs will have to be extremely frequent.

Approximately every 2.5 minutes in fact.

That's per satellite; each satellite is going to have multiple beams, so you'll have to do a beam handover like every 15 seconds and a satellite handover every couple of minutes

> Are hand-offs really all that complicated?

The fundamental problem is this:

   https://en.wikipedia.org/wiki/Two_Generals%27_Problem

Don't know how cellular handles this.

This page is awful, here's the article's content:

"SpaceX just received approval from the FCC to launch 4,425 satellites into space to build a low earth orbit network of satellites to sell home Internet.

Unlike current satellite Internet, these devices will be in a far lower orbit and offer far faster speeds without the data caps current satellite systems use.

The goal is that this new system will offer robust high-speed Internet, especially in developing countries and rural parts of developed nations like the United States. While you may not be running out to buy this if you have fiber Internet, it could bring true wireless Internet options to Americans who currently have no real options.

“This approval underscores the FCC’s confidence in SpaceX’s plans to deploy its next-generation satellite constellation and connect people around the world with reliable and affordable broadband service,” SpaceX President Gwynne Shotwell said in a statement.

SpaceX has already launched several test satellites to prove the system works. Now they have permission to move forward with a larger rollout of 4,425 satellites.

The system also promises to help relief efforts that currently spend hundreds of dollars a day for 5 Mbps Internet. With this system, relief workers can access high speed Internet even in areas hit by a major disaster."

source: https://www.theverge.com/2019/4/27/18519778/spacex-starlink-...

Kudos for the text.

This would be truly remarkable if this comes to fruition as it has many applications for those parts of the world without ubiquitous access presently.

Looks like they've got the pair from the "distracted boyfriend" meme in their stock image: https://knowyourmeme.com/memes/distracted-boyfriend

https://i.imgur.com/KYkIKbg.png

Ha! Since it's SpaceX I wonder if that was an intentional Easter egg.

That's not a SpaceX page though.

Good point. OK, so just a stock image then!

That pair is apparently pretty popular in stock images. I saw them just the other day in a local newspaper. [1]

[1] https://sobranna.postimees.ee/4460337/kolm-sodiaagimarki-kes...

For the frequent commenters about people not understanding latency, or the differences in technical terms around bandwidth, LEO/GEO, etc, imagine this: You may not be an economics or fiat currency expert, but given a choice of US dollars or Mexican Pesos, which would you pick? How do you know this? Do you work for the government or post frequently on the currency version of hacker news? No. You learn from people around you pretty quickly. If you're in a small town, you have limited options for bandwidth. There's Hughes Net (Satellite crap (high latency), but works if the only option) there's a new small Cable provider, there's DSL (phone company), etc. People chat, they gossip, they figure out how to get the best connection, in some ways embodying things straight out of movies like Hackers/The Matrix, even though they may own the local feed store. It's interesting to see. Don't underestimate people.

why link to this low quality scammy page instead of the original source: https://www.theverge.com/2019/4/27/18519778/spacex-starlink-...

I agree.

I wonder if this is a situation where flagging the submission helps attract the attention of the mods, so they can consider changing the link?

Can we update to the original source? https://www.theverge.com/2019/4/27/18519778/spacex-starlink-...

I have a friend who just started working on the assembling of these satellites and they are hiring like gangbusters. I was initially dubious that they would be able to make their number goal but they have people working 6 days a week 16 hour days to scale up to this goal. 4000 is a huge amount of things to build that you can shoot on top of a rocket. Not sure the longevity of the hardware.

People working 96 hour weeks deliver shitty quality.

I'm pretty sure he meant the production line is running 96 hours a week. They probably have it split between 2 shifts so each person is only running the line half the time.

2 shifts but the push is def to have people work more hours. Seems the main goal is figuring out how to make all the satellites with relatively unskilled staff(relative to satellite building. prior to this my friend worked at a bike shop and construction and has a BS in physics).

> I was initially dubious that they would be able to make their number goal but they have people working 6 days a week 16 hour days to scale up to this goal

If they have to make people work 96 hours a week isn't that evidence against them making their goal, not for it? If they were progressing according to schedule, with buffer for unexpected events, surely people would be working sane and sustainable work weeks?

They started with this schedule even before they had full public approval.

Regardless of latency, I’m signing up. Anything’s better than Comcast!

This right here is what they're banking on :)

And they have plenty of reasons to bank of that ;) .

Comcast being slow hasn't been a problem for the majority, Comcast being expensive may have been.

Comcast having terrible customer support is another big problem.

How often do you need to call the customer support? I have had Comcast for 6 years now and I call them once a year to renegotiate the deal or move the connection.

That's a terrible excuse for having bad customer support.

High latency satellite internet already exists (re: HughesNet)

I'm genuinely curious, can you have it without your landlord (if you rent) approval and also install the ground transciever without HughesNet technicians? Sometimes they refuse to install in particular locations on the grounds of perceived landlords disapproval (?)

Yes you can. More here: https://www.fcc.gov/media/over-air-reception-devices-rule

Not a lawyer but there is definitely a law in the US which prevents landlords from not allowing tenants to install satellites for television. I'd imagine that the same law might cover generally any consumer telecommunications equipment

Interesting, I see reports of latency of 60ms on average [1]. Starlink claims it will offer as low as 25ms [2]

Is 35ms a significant value proposition, considering 5G is on the horizon?

> As of March 2019, HughesNet's average download speed is 11.04 Mbps. Throughout their coverage area, the average latency on HughesNet Internet speed tests is 61.87ms. For context, wired terrestrial Internet connections usually output latency results in the 5–70ms range. [1]

[1] https://broadbandnow.com/HughesNet-speed-test

[2] https://www.zdnet.com/article/spacexs-starlink-takes-a-big-s...

That doesn't seem right. Napkin math:

GEO Satellite is 22,236 miles above sea level[1]. Speed of light is 186,282 miles per second[2].

Therefore the absolute fastest information could travel on a GEO network is 22236/186282 = 119 milliseconds (one way at the speed of light), which is 238 ms round trip. In reality there are going to be internal and network latencies so I would expect something more like ~300-500ms RTT.

[1] https://en.wikipedia.org/wiki/Geosynchronous_orbit

[2] https://en.wikipedia.org/wiki/Speed_of_light

That's right. Geo will typically be around 600ms. The speed metric is incorrect/misleading as well. Both Hughes and ViaSat offer multiple speed plans that are vastly different. You can't simply take an average, or your speed isn't representative of what the service could do. Of course, satellite internet will pack a lot of users in there to fill up the satellite. I don't be naive about that, SpaceX will do the exact same thing.

> You can't simply take an average, or your speed isn't representative of what the service could do.

Why not? We're just comparing current satellite broadband offerings' known latency to what Starlink could potentially offer.

If your cable service offers 10, 25, 50, and 100Mbps plans, how is an average speed at all meaningful? It's just representative of how many people sign up per plan.

An existing offering does 60ms average, meaning its best case is better. Starlink would offer 25ms best-case scenario.

My post is clearly about bandwidth, not latency. You don't choose your latency.

> That doesn't seem right.

broadbandnow.com is a legit site that tracks internet providers and speeds by aggregating data.

Yeah but... it's claiming information can travel faster than light...

It must be averaging in terrestrial network latencies or something, because GEO satellites are literally hundreds of light-milliseconds away from earth

The solution to that problem is to get municipalities to exit their monopoly agreements with broadband providers.

Spending more tax dollars on satellites isn't helpful. That just gives your representatives an easy way out in the near-term, and probably results in everyone getting upset over wasted money in the long term.

What "tax dollars" are we talking about here? It's a private system.

Heck, I already have FIOS, but if it's reasonably priced I'll subscribe just to support it (and to have a backup). Musk is basically the closest thing we have to Tony Stark. If that's not worth supporting, then I don't know what is.

Everyone is super excited about this and I am sure its going to capture a significant market, but you have to realise what are alternatives and how much they cost.

I expect them to be utterly unaffordable at least for first half of decade.

Their biggest competitor is Iridium which offer similar service at $150 per 2kbps. I will let you extrapolate real life prices from here.

SpaceX should be able to undercut that some since they can launch their satellites at cost and using a booster that's already been up once or twice really brings that cost down.

Sure, but why would they undercut them by 6-7 orders of magnitude in price? Seems silly to just leave money on the table.

Bigger less profitable userbase vs larger more profitable user base. The question is if the bigger userbase option is big enough to make overall profits larger than they would have been with the smaller one. I have no idea.

Iridium is not their competitor. Different market. Even the CEO of the company said so.

Sure, terminals are likely to be different, but service is the same. I don't see enough differences between two.

So many latency questions. Do a basic search: https://en.wikipedia.org/wiki/Starlink_(satellite_constellat...

Yupp relevant bit from there:

Internet traffic via a geostationary satellite has a minimum theoretical round-trip latency of at least 477 ms (between user and ground gateway), but in practice, current satellites have latencies of 600 ms or more. Starlink satellites would orbit at 1⁄30 to 1⁄105 of the height of geostationary orbits, and thus offer more practical Earth-to-sat latencies of around 25 to 35 ms, comparable to existing cable and fiber networks[51] (although transmitting a signal halfway around the globe takes at least 67 ms at the speed of light).

Is your single page app not yet designed to be satellite compatible?

It looks like they are quoting "as low as 25 ms".

the biggest win here are productivity gains. After high speed internet is available, you'll be able to work in the bush with a laptop. away from ridiculous rents and rent-seekers.

Yes, this is going to change the world in a big way. High speed global communication is a paradigm shift. If SpaceX cheap reusability and Tesla all-electric really end up doing the things they promise on a huge scale, then Elon will be 3 for 3 on truly world-changing advancements.

There are at least 5 competing constellations that will be higher throughout and/or out first. Spacex's is not new.

Your going to have to give a lot more details than that blanket statement because I have been following starlink closely ever since it was announced.

Oneweb is their main competitor who has already launched test satellites but they are going to launch on other companies rockets which are much more expensive than spacex's especially now that spacex is getting reusability down.

Amazon just announced their constellation plans and they either have to launch on expensive non-spacex rockets or have to use blue origin which while they are planning to have fully reusable rockets, those are still years out.

What are the other 3 companies that will be out first and/or have higher throughput and/or how are Amazon/Oneweb better?

Oneweb, telesat, ViaSat, o3b (mpower), and Boeing have all announced. A study from MIT showed telesat's to be the most cost effective from the LEO bunch [1], which is important since it's not clear SpaceX has a path to revenue [2]. and if you've been following starling closely, you know that they will not have anywhere near their full deployment for over 5 years after the first launches. the entire fleet is required for the capacity they have been touting, not to mention the coverage.

And the argument that SpaceX has some kind of moat because of their launch business is simply not true. there are many launch providers out there, and launch costs have gone way down partly due to SpaceX, but also because satellite orders have decreased significantly. SpaceX as a company, needs as much revenue as possible to fund the satellite venture, since their entire company is depending on it. The launch business is not sustainable in providing enough revenue in the future to keep them in business. so SpaceX will have to fight for business from all the other satellites just as much as any other company.

1)https://www.google.com/url?sa=t&source=web&rct=j&url=http://...

2)http://tmfassociates.com/blog/2019/04/08/high-times/

> A study from MIT showed telesat's to be the most cost effective from the LEO bunch [1]

I just read that article and it makes no claims whatsoever in relation to costs.

> which is important since it's not clear SpaceX has a path to revenue [2].

Path to revenue? What does that even mean?

> if you've been following starling closely, you know that they will not have anywhere near their full deployment for over 5 years after the first launches. the entire fleet is required for the capacity they have been touting, not to mention the coverage.

US/Europe coverage is going to be their primary initial target as that is where the most money is and that requires a significantly smaller amount of satellites. Care to enlighten us on what other companies are planning to launch production satellites like spacex is doing next month because the only company I am aware of that has even launched test satellites is oneweb.

It gives a bandwidth efficiency ratio, which is directly tied to cost since the more efficient per bit the system is, the cheaper it is to run. If telesat's is 4x cheaper per bit, how would SpaceX compete?

Path to profit.

You are saying SpaceX launch a handful of these satellites is really going to have any effect?They already launched some and they had propulsion problems. They need upwards of 500 of these in the air just to compete with satellites that have been up for multiple years already.

> It gives a bandwidth efficiency ratio, which is directly tied to cost since the more efficient per bit the system is, the cheaper it is to run.

The source you linked said Telesat had a 4x Gbps/satellite bandwidth over spacex which is not directly tied to cost. Telesat has no mention of satellite weight and spacex plans to launch 40x the amount of satellites as Telesat for their initial constellation and 100x at full capacity if I recall correctly.

> Path to profit.

Spacex has reusable first stage rockets. I don't see how any of the other mass satellite constellation companies that you mentioned can have better margins than spacex.

> They need upwards of 500 of these in the air just to compete with satellites that have been up for multiple years already.

Do those 5 companies you just mentioned somehow don't?

Blue origin will have the same, or cheaper costs by the time it matters. Not sure what your last comment means, but 3 of those 5 are slated to have far more capacity in the sky by 2022.

Read the study again. It's useable capacity. You cannot use the 20Gbps number SpaceX advertises.

So who else is planning to have 1600+ satellites in orbit by mid 20's?

And can any of these competitors compete on orbital insertion price / rocket availability with SpaceX?

The entire concept is that SpaceX is basically going for backbone global fiber delivery, not end users as first customers at first at least.

As long as SpaceX can do the Satellite tech needed, I can't see how they can loose long term. Elon does not think small.

The number of satellites is not relevant. It's a single parameter a large number of them which describe how well the constellation will perform. Please see here for more detail:

https://www.google.com/url?sa=t&source=web&rct=j&url=http://...

The satellites are not the hard part, even though they are extremely hard. The hard part is going to be getting a suitable user antenna for a low enough cost that they will make the money back. So far they have not spoken publicly about their user terminal or cost, other than a couple sound bites musk said years ago about how low he wants the cost.

I can actually see this working as a backbone provider. Take any underserved area, rent space on cell phone towers or water towers or grain silos, and deploy an all-in-one kit that has the Starlink antenna along with a WISP transmitter and solar power. Also would work for apartment owners who want to get an additional revenue stream by being the sole provider of internet to their tenants.

So what? The entire purpose of Starlink is to increase global demand for launch capacity. That's the only way they're going to reach the economy of scale to be able to actually reduce launch costs as much as they're capable of. They can break even or even take a loss on Starlink and still achieve a valuable strategic goal.

Internet was supposed to change everything yet we are stuck in cesspool of misinformation.

100% sure Tesla will either apply great firewall in China or just shut sats down while they are there, because China will threaten shutting gigafactory.

The internet did change everything, despite its being used to spread misinformation. They are orthogonal.

It is no surprise that an ISP operating in China will be subject to Chinese law. The last-mile method is not really relevant.

It haven't really changed law and politics like cyberphunks hoped.

You can't change law with technology...

and with 600 ms ping you can't game, so that's even more productivity right there

600 ms is for those with geosats Internet. Low flying constellations offer 10-100 times lower latency, see other comments here.

Are you implying your laptop is going to have a phased array antenna mounted on top of it?

They already make Inmarsat (BGAN)/Iridium WiFi hotspots. This would be no different. Power and view of sky go in, Internet comes out.

What about rainy clouds and thunderstorms? While i want to be outside in sunny weather and work on my laptop during rainy day - that's when the connection quality is worst?

Heavy weather will almost always diminish satellite connectivity. Will depend on what Ka/Ku bands will be used between satellite and terminal.

Those antennas are extremely expensive and large, so the OP's dream is largely just a dream.

Google image search "iridium hotspot" and "bgan". They range in size from a small ipad to a large ipad. Pretty reasonable for global connectivity (although not built into a laptop's frame).

Those small iridium hotspots are also much lower bandwidth

2kbps to be precise

And the starlink antennae they "hope to get down to the size of a pizza box" (which also of course needs to be powered). This is not a mobile solution.

If I can fit it in a pelican case in a checked piece of luggage (62 linear inches, up to 50lbs), it’s mobile enough. Carry on luggage compatible would spoil me.

They also weight 800g.

You missed the "expensive" part, and iridium is not comparable when looking at speeds.

The target price is (was as of 2015) $100-$300. Really not that expensive.

https://web.archive.org/web/20150329174815/http://shitelonsa...

The target price means nothing. Musk hasn't talked about them in years. Other companies have tried (and failed) and low cost phased array. Until they're delivering at that price, think of it like musk's original Tesla production rate predictions.

Which he hit, to be fair.

This could pipe unfiltered Internet into places like China/NKorea/Iran.

One of my favorite features of it. No one can stop the dissemination of a free internet then.

It will be difficult to hide the dish that sits on your roof, blasting signals into space.

Sure - if the want to risk China/NKorea/Iran shooting those satellites out of space. Seems a bad gamble so I doubt they'll provide service to those countries.

No one has ever shot down a satellite that wasn't theirs in human history, I don't believe.

Not yet ;)

While the DPRK would have no means of doing this, the PRC could quite plausibly launch its own jammer constellation if it became enough of an issue.

The most interesting aspect is that an import ban on LEO satellite modems becomes exponentially harder to enforce when you’re the only country that can manufacture them at scale in the first place.

I'm 90% confident that if SpaceX ignored international (and Chinese) law and started broadcasting into China without permission the PRC would be delighted at the excuse to test anti satellite weapons instead of trying to jam them.

Of course, SpaceX wouldn't dare risk the international firestorm of doing so intentionally. But if the service were available in Taiwan, mainland China is only about 100 miles away across the Taiwan Strait.

The connection might be slow and spotty from Fuzhou, but all you'd need is a modem sold out the backdoor of a factory and an account created in Taiwan (perhaps a friend you Alipay for the subscription), and you'd have unfiltered internet in eastern Fujian.

Repressive regimes will ban importation and possession of the antennas, and will prevent citizens from paying for services. A few courageous dissidents will defy the bans but not enough to matter.

I don't see pieces of metal being possible to ban. Even a pizza pan would do.

You have to pay for the subscription.

A pizza pan will not do. This service requires specialized active antennas with beam steering ability.

I.e. Russian law has a catch for satellite antennas: you can't set them up without a license with a penalty by confiscation and a small fine.

What's going to be the power and size requirements of the ground transceiver? Do we have details on that?

If Starlink can provide 4g quality service to Canadian cell subscribers at a reasonable price, they would have millions of users in months.

It requires a receiver about the size of a pizza box so it is not intended for cell phones.

Then again based on the trajectory of phone sizes the past few years, it might not be too far off in a couple of years. ;)

I'm not a hardware guy, but i doubt it. They would need to reduce the size and power requirements by an order of magnitude each of which we are currently struggling to do nowadays. Most importantly though, the wavelengths they are using i do not think penetrate buildings well and I don't think any of other wavelengths can effectively transmit that much bandwidth through buildings from space efficiently/economically.

Not only that, but phased array relies on the radio signal hitting different antennas at different times. So the array of antennas have to be spaced a minimum distance apart depending on the wavelength used.

No, elcritch is saying that phones will be the size of a pizza box in a few years.

No, it's impossible. Antenna theory dictates what the size of an antenna can perform at. Without significantly reducing the noise temperature of the antenna much farther than anything else out there, it will never happen. And noise temperature is pretty much guided by physics at this point.

He's saying we might soon have pizza-sized phones.

Ah, that's more likely :).

It can't. The size of a receiver is that of a pizza (this is the only way I've ever seen it described, I wonder if there is a more precise description somewhere) not that of a cell phone antenna.

It might contribute to providing backhaul services making cell-towers cheaper to deploy, and it might enable things like sticking an antenna in a vehicle, but it can't provide 4g style cell phone service.

Would it be feasible for them to build standalone cell towers of their own that connect to these space networks? So rather than "no cell towers at all", the benefit they provide is "no cables at all". They would just go around to remote areas and build towers without needing to lay down the cables. (disclaimer: basically don't understand this stuff at all haha)

Yeah, that's basically feasible and your intuition of the cost-savings / requirements is accurate. A cell phone monopoly doesn't have any incentive to pass on those savings to customers, but maybe a small group could band together and buy a portable base station to share.

Remote towers often have wireless backhauls anyway. But if you only want a cell or two of coverage surrounded by a vast dead zone then it's likely viable somewhere.

Yes! Many comments on r/spacex suggest that being a good use case for them but they have one major downside. Weather can affect satellite network connectivity which brings their availability down a few nines and many people expect most everything to run 100% of the time. I know growing up, I convinced my parents to try out directtv and my dad always got so mad when the weather caused the satellite tv to go out so it isn't perfect. Therefore, I don't expect it to be used by most people unless their only other opens are hughesnet or dsl.

In theory yes, but SpaceX would have to purchase 4G/5G terrestrial spectrum which is extremely expensive or sometimes unavailable at any price.

https://twitter.com/elonmusk/status/1020479995028754432

Random twitter user (Anner J. Bonilla🇵🇷 <more emoji's, for some reason only 1 renders on HN>)

> can Starlink be used to back haul LTE/regular cell in rural areas or emergency situations/disasters? Seems like a great thing for disasters where back haul is damaged but not sure how useful it be due to bandwidth/latency?

> Would have been super useful in Puerto Rico.

Elon Musk

‏ > Yes, that will probably be its first use

Sure - but unfortunately Rogers/Bell/Telus will be sure to embargo any such customers as "likely spammers" to keep their ridiculously high prices up.

folks, the latency of other space-based internet services is because you're talking to satellites out at geosynchronous orbit. starlink is low orbit, and depending on the route your packets need to take, might be lower-latency than ground-based links.

The sheer ambitions and speed of execution of SpaceX (and even Tesla) is exhilarating. I hope they make it happen and put a dent in the deeply entrenched incumbent monopolies who are abusing their position. I would buy the service in a heartbeat.

What are the odds that all Teslas magically get Starlink? Seems like a nice way for Musk to prop up one of his ventures with service fees from another.

I could see this actually reduce the costs in fact. Right now Tesla's all need gsm/lte support for updates. This would let the updates work anywhere in the world without the other infrastructure that's needed.

Someone still needs to invest in Starlink and pay for upkeep.

Just because you own multiple companies doesn't mean one company can provide services to the other for free.

That would be like your family member working for you and you not paying them because they're family.

Musk has specifically said that this is not a mobile solution and won't be used for his vehicles. The antennae is too large to be practical (the size of a pizza).

Can you quote a source for that? I did a bit of searching and can't find one. I don't see why a pizza sized antenna is much of a problem for a car.

SpaceX won a $28.7 million fixed-price contract from the Air Force Research Laboratory for experiments in data connectivity involving ground sites, aircraft and space assets [0] so they definitely are looking to put these onto vehicles.

[0]: https://www.geekwire.com/2018/spacex-strikes-28-7m-deal-air-...

This is right on. And I suspect it will also be used for Tesla to Tesla communication so Tesla vehicles share information (slow down ahead, etc) with each other.

How is it helpful for my car to send a message to space and back in order to communicate with the cars around me?

There are possibilities that can be enabled if the vehicles can communicate with each other. In the absence of other alternatives, using Starlink may be the way to do this.

Who else besides the FCC needs to approve SpaceX launching over 4,000 satellites into space? That seems like a fairly significant number of satellites, but admittedly I am a layman in this area.

FAA: https://www.faa.gov/about/office_org/headquarters_offices/as...

Space is pretty big

Until it’s not - https://en.m.wikipedia.org/wiki/2009_satellite_collision

The ITU as well. Part of their proposal involves reuse of spectrum currently allocated to geostationary satellites, and the mechanism for noninterference is physical separation: while they may transmit on the same color as a GEO-sat, they won't be simultaneously visible from a normal antenna for GEO use as they will point in a different direction. The GEO-sats (and their spectrum allocation) is confined to the ecliptic, while these LEO-sats will be transmitting from any direction except overlapping the ecliptic.

Each country more or less is responsible for regulating itself. The International Telegraph Union sometimes comes into play for spectrum issues, but I think most of their influence is in GEO since they handle slotting there.

It is a pretty significant number of satellites. For whatever reason the FCC has taken up the role of regulating satellite collisions and such, and if you go dig up SpaceX's fillings you can see them discussing mitigating issues related to this (keeping probability of a collision for the entire constellation less than the acceptable number for a single satellite, making sure the satellites burn up on re-entry to mitigate "a satellite fell on my head" risks, etc).

I'm curious specifically about the prospect of circumventing firewalls in China or other places where internet access is heavily restricted and censored. I imagine that China could tell the US government to tell SpaceX to cut it out and cite various relevant international treaties, but in a lot of ways it's more of a political question than a legal one. I doubt many people outside the North Korean leadership would object to providing Internet access to North Koreans, for instance.

China has the ability to shoot satellites out of the sky. Now if they have the political will to do so remains to be seen. But they can also easily jam them in their own backyard.

How would the Starlink solution compare to Iridium's NEXT? Is Starlink simply a larger-scale version of the same idea, or is there some special sauce in Starlink vs NEXT that would differentiate their potential use cases?

From what I can tell, they are both LEO solutions but Iridium is using far fewer satellites to achieve 100% global coverage. I assume there is some reliability metric or other more obscure aspect that would make someone want to choose one over the other for some particular application.

The only tangible differentiator I can come up with right now "in favor" of Iridium (aside from the fact that it's already up there and working) is the multi-mission aspect of the constellation - science experiments, DoD contracts, ADS-B for Aireon, etc. But, for someone who is seeking an affordable, satellite-bound 50+ mbps pipe to the internet, a 1000-10000 satellite constellation sounds like it's more appropriate.

One big differentiator is the nature of the antenna needed. The phased array antenna for starlink is apparently the size of a pizza box. Iridium satphones are comfortably handheld.

Is this a consequence of Iridium having L-band capabilities, or is it something else in the design?

It has to due with the phased array antennas being used, which is basically a grid of antennas where each receives the signal at a different time (due to speed of light propagation). By delaying the processing of signals an appropriate amount from each antenna, all the individual signals can be combined to be the equivalent of pointing a dish antenna directly at a given satellite all the time as it is flying overhead.

Fun idea: On-orbit CDN endpoints with predictive caching to warm up the next satellite before it passes overhead.

If you think of this as a graph database problem, it becomes pretty easy to solve. I'm sure this is how they will load balance between the satellites that you can see in the sky as any one moment.

Even better, you can pre-calculate this as long as you know where all the base stations are. Dynamic registration should be pretty easy to do too as it will need a GPS chip in it.

Why only wireless internet from space? Will they provide a wired option in the future too?

(Edit: this was a wires to space joke)

Less infrastructure. Why build towers when you can buy internet from space. Also you can sell world wide in seconds. You can sell it in china behind the firewall. In india in the middle of nowhere. In south america. All with no towers or wires.

> You can sell it in china behind the firewall.

That sounds like a stellar way to get your satellites shot down.

Or they'll just block import of your antennas...

Can China disrupt the frequency somehow? Considering there will be thousands of them in constant orbit that sounds like a difficult thing to do.

Much easier to regulate the "pizza box" receivers I guess. But they can be mobile and taken down when not in use.

SpaceX could disable ground to satellite connections over China if they requested that.

> You can sell it in china behind the firewall.

Yes, because the police can't figure out how to raid someone who puts a satellite dish up on their roof.

Please tell me you're joking.

These satellites are 100km up, moving at 8km/s. You're not going to be able to run a cable from them to your house.

550km

The op clearly means a traditional wired service like Google Fibre. E.g 'SpaceX Fibre'

Why would SpaceX run fiber? Wouldn't that be more in the boring company's line?

Strictly speaking the boring company is part of SpaceX. Not that this addresses your question.

I don't know. I'm not the one who asked the question. I'm simply clarifying what someone asked.
Alternatively, they could be asking for 'wired' in the where there's a central base station, and each individual home has wired connection to that.
Regardless, I assuming the op _didn't_ mean running a physical wire from a sat in space.

FWIW, the OP's wording was confusing. It took me a minute to realize that they were talking about something like Google Fiber, not literally running a wire from Earth to an orbiting satellite.

"SpaceX Fibre" sounds like a space elevator product from SpaceX ...
... which then probably could technically supply "wired internet from space"

That was the joke actually

Not with that attitude

SpaceX has a competitive advantage because they own the (reusable) rockets. I mean, it's in their name...

I'm curious if this will become an ideal service for hackers or others seeking to hide identity to use as a random and mobile location from which to operate? Assuming it becomes ubiquitous as there are multiple companies racing to offer these "constellations".

You are triangulating yourself, while broadcasting kinda loudly to the sky. So not directly. This is no hackers pancea. But a network of them hidden on rooftops connected via side channel may find effective use.

I do wonder a bit why why they need THAT many satellites. Assuming an orbit at 200 miles altitude, we have a horizon distance of about 2000 miles. Comparing the area of that 2000 mile radius ground patches with the surface of the Earth, we need about 10 such patches. Filling in the gaps between patches might require 10 more satellites. Naively I would have assumed that orbital mechanics costs us another factor of two, so fourtyish satellites required. But they plan to launch more than 4400 satellites. More than 100 times the naive estimate. And at the cost involved they don't do it for fun. Where does that discrepancy come from?

Is your horizon distance calculation based on no obstructions? Most people don't live on the plains ;)
I am genuinely curious how you arrived at that number, FWIW – I don't know how to go about calculating something like that.

That does indeed assume a sphere. If you are curious about the geometry, maybe https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizo... can help.
If you run the calculation the other way around, every satellite has to service a ground patch with about 380 miles radius. And your antenna has to swivel to a point that might be more than 60 degrees away from zenith. So every obstruction of more than 30 degrees above the horizon will lead to at least intermittent disconnects.

Better to get approval for too many than not enough?

More bandwidth and better resilience against loss of individual satellites? Similar rational to how when you install a wifi network in a high density usage environment you want to use a lot of lower power access points each covering a small area to get better throughput for a large number of users rather than trying to cover the whole area with a small number of higher power AP that each cover a wider area.

I have thought about bandwidth, but that should only matter once you have a lot of customers.

You launch that many you expect a lot of them fall down I suspect. Probably some go into a higher orbit and serve as spares until they decay into some more appropriate orbit.

Area of earth is 170 million square miles. 2000 mile radius patches have 12.5 million square miles. Even assuming perfect tiling, 10 wouldn't be enough.
Throw in realistic angle limitations (not horizon) and coverage per satellite rapidly decreases

Ok, make it 14 instead of 10 then. That's a small correction. Filling the gaps on the other hand does not require a factor of two, but only 2 \pi / sqrt(27) or about 1.21. Multiplying the 14 with that gives us 17 instead of the 20 I estimated. I don't want to squabble about 20% here, but ask about the factor 100 discrepancy between naive estimate and projected number.

That is because you’re expecting ground access points to magically communicate with a satellite at 0 degree elevation. With a realistic elevation to deal with obstacles, diffraction, and electronic steering limitations, you’ll end up with a radius of coverage closer to 200 miles, which would give you that factor of 100. This shorter radius also limits losses due to distance attenuation. Your naive calculation assumes the limiting factor is the curvature of the only planet, which it is not; the earth could be a flat slab and you’d still need the same number of satellites.

This is just a guess, but maybe to simplify the tracking requirements on the ground?
With a minimal satellite system, your tracking needs to follow satellites all the way across the sky, and probably also needs to be able to rapidly make large changes in where it is aimed.
With a very large number of satellites, a ground station might be able to get by with only having to be able to track within a small part of the sky.
If you have enough that there are many of these small areas that always have a satellite in them distributed all across the sky, then even places that have a lot of buildings or trees blocking much of the sky should still have some patch they can view that works.

Two reasons: more bandwidth, and more coverage in a specific region. One of the biggest downside with a LEO constellation is that only a few satellites are covering a given area at a time. Most of them, by far, are over water, where there's likely little to no usage. So because of that design, do you have to launch a lot of satellites to make up for the lack of throughput in the single areas.

Other people mentioned the issues with antenna obscura— buildings, walls, trees etc can all get in the way.
If you connect to a satellite at an oblique angle, it is also much further away. A satellite in a 500km orbit is 500km away from you when it's directly above you. But when it's on the horizon, it can be more like 2500km away.
This adds a little bit of latency (maybe 10-20 ms). It also hurts the signal, since going through atmosphere attenuates signals more than going through vacuum. Especially for Ka band signals, which particularly weakened by water vapor.
On top of that, SpaceX needs to have redundant coverage over an area. You don't want your customers' internet to stop working because a bit got flipped on one of your satellites or a thruster blew up unexpectedly. Also, a single satellite may be able to handle Alaska or Siberia but have bandwidth issues handling the state of California.

If you have any interest in this sort of thing, get your amateur radio license and start making contacts on AO91/AO85. It's so much fun to talk to someone 500 miles away with a walkie talkie, through a satellite.

This could eventually open up other markets for SpaceX. A communication network with that density would be able to offer a better resolution than GPS and sets up SpaceX to be a key backbone service provider for autonomous flying vehicles in any form. Be that personal transports/air taxis or courier drones.
Whilst not the intended market initially and might be some design considerations that prevent that level of branching out. But certainly, something to ponder down the line.

Offering a GPS-like service would require totally different hardware. Each GPS satellite has 4 atomic clocks. The StarLink satellites will basically be optical routers and their timekeeping needs can probably be handled by a cheap clock and NTP from the ground.

Could have multiple clock sources on earth that produce the clock signals for the satellites. So a satellite could get an accurate time if it locked onto a few ground based sources.
Just with that volume and density of satellites, kinda begs some lateral thinking.

The question i'd like to have answered: How long the sattelites actually last, considered the amount of space junk in orbit and amount of sattelites? Do they intend to launch several sats/day? https://www.reddit.com/r/Starlink/comments/9ud7s7/starlink_s...

A really interesting side-effect of the mass production of thousands of satellites for this constellation will be to make spacex a player in the satellite building business, bringing satellite production costs down significantly, and thus boost demand for their launch business, it will also demonstrate a high rate of launches. The two businesses can feed off each other, along with the revenue from starlink. Interesting strategy.

If their service is reliable, I would join right away. I'm in a populated area and our internet is absolutely terrible. My internet stops working at least 5 times a night. I called the provider numerous times and I plan on switching. The problem is that the competitor isn't much better. I can't wait until someone disrupts this POS industry.

I can see the appeal for customers who in rural areas with one or no real option for internet access, or if you like to vacation / travel via RV.
Will the SpaceX system use frequencies that allow decent reception and transmission (to the sats) if you're physically in a city? If you're indoors?

Is snooping on satellite internet traffic a thing? Wonder what security implications this could have.

It's a radio technology, so yeah. Similar problem space as WLAN, at least in the sat -> earth direction.

Oh it absolutely is. You park your collection satellite right behind the target satellite, so you soak up all the transmissions that overshoot.
http://spaceflight101.com/shijian-17-rendezvous-with-chinasa...
The NSA has been known to use their imaging satellites to find transmitters which they can then snoop on once they know where they are pointing.

The real end game has to be servers in space. Think about a potential extreme privacy model where servers exist outside the domain of laws on earth.
Of course, to be cynical, no earth-based company can escape being squeezed into doing what law enforcement agencies might need them to do.

Starlink I think can consider heavily leveraging a multicast or hypercast protocol considering most bandwidth usage is related to video streams. Many downlinks can accept a broadcast level packet.
How does a system link Starlink handle channel and spectrum allocation?

Are there informations available on the estimated cost to consumers for this service? Would it even be directly purchasable by individuals?
Edit: rephrased to emphasise cost for consumers (not launch cost), an engine search didn't return an answer

Musk said $50 USD or less at one point, but I don't have a source for that at the moment

How long till it's possible to deploy static content to "edge" nodes in LOA? Traditional CDNs typically advertise their geo-distributed POPs on a 2D map. I want my cloud provider to live above the clouds.

What are the implication with regards to space debris? I hear it's a very real, growing problem. Will those satellites be able to withstand hits? Will they produce a lot of debris (if 2 collide for example)?

There will be a more intensive commercial incentive to fix it, so that's presumably a good thing?

1. Space is really big so the odds of anything hitting each other are low.
2. They are launching their initial satellites in extremely low earth orbit such that atmospheric drag will cause them to decay and burn up in the atmosphere within 5 years. They are also attempting to design their satellites such that every single part of them will burn up in the atmosphere so that there is no risk of any piece hitting someone.
3. The US government is also concerned about this which is why spacex is doing their initial launch into a lower orbit that guarantees their decay into the atmosphere. Their future launches into higher orbits with longer decays will have extra considerations for such problem and thus will be evaluated by the US government individually so I would not be too worried.

They probably won't be able to withstand hits. However they have the ability to maneuver if necessary, and even if there's no maneuvering capability each one should deorbit on its own in less than a decade.
Probably the biggest concern (and this is still a very small concern!) is debris making it back to earth without burning up. The SpaceX FCC applications list some parts of the satellites that won't necessarily burn up on reentry, and some of them are large enough to ruin your day. That said, the surface of the Earth is really really big and unless something goes wrong with a satellite they'll intentionally deorbit it over the ocean so no one gets hit by space junk.

Once there are space hotels, surely they’ll be the default internet provider

How many of these satellites can they orbit with 1 Falcon launch?

For some reasons, I think underwater transoceanic cables are much more reliable for high speed internet that satellite based internet connectivity, for now at least.

Does anyone have more details about the ground transceiver? How large will it be? What are the power requirements? How much view of the sky does it need?

Does anyone know the EE/physics of the signal loss over that kind of distance?
What kind of band can reliably transmit that far with low power and high SNR?

Do you have to have a clear view of the sky to access this, or would it work under a roof?
Also, what's the total bandwidth available?

Is it time to seriously start worrying about Kessler Syndrome (https://en.wikipedia.org/wiki/Kessler_syndrome)?
The individual satellites might degrade relatively quickly, but a collision cascade could make the system unfeasible for years at a time and a certain percentage of the garbage would be kicked into higher orbits.

5G is going to kill any prospects this internet service will have in big cities within the next 5 or so years. That leaves the rural and less served areas. Can the service be cheap enough without subsidies when a big chunk of the population won't be using it?
10 years ago this would have been a great business. I suspect the business will end up being a place to sink money for Space X.

I think you underestimate how much of America is "rural area" , that alone is a huge market that towers will never fill.

A lot of area with few customers. Will this tech truly work well? I recall using a satellite dish for access to more TV channels years ago was never quite reliable enough to be enjoyable. One storm or decent cloud cover and it was out.
This feels like another of Musk's ideas that's like, "give me a ton of money and I'll make this happen, and it only works if I can launch 100 satellites which will cost a few trillion"
How many of these have panned out? When has Musk made a profit? Will investors do due diligence this time, or just throw money at him because they perceive him as successful, despite the fact that his only profit came from a lucky website sale just before the dot com bubble burst?
I guess banks will pump this so they can get the business, and the general economy will be left to absorb the blow when this fails to meet expectations, like the rest of Musk's promises.

People that are a lot smarter and more educated in this subject matter than myself have looked this idea over (at least I hope so). And based on my level of understanding, the phased array antennas should be able to dynamically adapt to interference similar to how MIMO antennas work on wifi routers (the ones that have 2 - 4 antennas on them). At least is seems like a plausible enough idea that multiple other companies are going to be attempting the same thing.
The legg up that Spacex has is potentially very low cost launches on reused rockets. But I have a strong feeling that the major cost savings will only appear if and when BFR is ready (and if it does what is claimed).

Musk continues to promise more and deliver less. In my opinion, the fact that he's never delivered a profitable company disqualifies him from leading any major venture.
> People that are a lot smarter and more educated in this subject matter than myself have looked this idea over (at least I hope so)
This was often said of companies before the dot-com bust, and very often said of Enron. Everyone thought someone else before them had done due diligence. Now that the economy has been doing well for awhile, it's worth taking another look at ideas put forth as "it can't fail".

It seems you're attacking Musk as a person more than the idea. SpaceX is doing undeniably well, who you can attribute that to is up for debate, but my point is you should be critiquing the idea, not the man.
How about hope for the best and if you don't believe in them, then don't invest?
Imo it's a really good idea, and I'm glad someone is trying to solve the broadband issue in rural America, because there's a serious one. I live out here, you're out of touch if you don't think there's a market.

To turn this idea on its head...maybe SpaceX will be able to compete with Verizon/AT&T etc. by providing a global Internet service that also has some way of connecting to phones. I'm imagining having an Internet and cell phone plan in one, all powered by Starlink, with no roaming or other B.S. to deal with.

Isn't this a solution in search of a problem?
I remember Robert Pera, founder of Ubiquiti Networks, poking fun at Facebook for floating [pun intended] the idea of a giant hot air balloon to provide internet access while pointing out that Ubiquiti is already bringing high speed internet to remote places all over the world. I agree - skip the satellites just buy some some Ubiquiti gear.

Ubiquiti has made WISPs cheaper and easier yet there still seem to be plenty of places that aren't covered by WISPs.

And in my area a WISP would have a hard time getting it's upstream bandwidth because of no nearby large cities and therefore no high-speed fiber for a good distance.

I love how they added “wireless” to the title, as if to imply there is a wired space internet.

For all the chinese users behind the wall, latency is not a problem at all for all.

Hopefully to see this wonderful innovations during my lifetime. I am 50 yrs old.

The economics of megacities, 5G and fiber strongly disfavor Starlink for the world's richest urban populations. They will have a difficult time finding enough paying customers in the barren spaces of the world.

How does this work when things need to be launched into space? I get that 4,400 spread out over such a large area makes them minuscule but it's still something.

They are tracked and avoided, just like all the other satellites already up there. Low earth orbit is a large place, you could increase that number by many orders of magnitude before you'd have to start worrying.

Couldn't the latency problem be at least partially solved by moving servers to LEO as well? At least as a CDN?

Servers break a lot, so no.

I hope they call it Skynet.

if anyone here thinks this stuff is super cool and wants to figure out how to solve internet for the public, by making it as cheap and as fast as possible, while private, please shoot me a note at james@communityphone.org (it's my life)

I guess it's time to move onto the next shiny thing to keep the fan-investors entertained. I wonder how long they can keep this up.

How do clients retransmit data without extremely high latency? Is it just that LEO satellites aren’t high enough for it to be a problem anymore?

The satellites are only a few hundred miles away, and light travels faster through the atmosphere than it does through copper or fiber.

Yes. LEO is a lot lower.

EDIT: I was wrong here to criticize the latency since SpaceX's implementation will attack the problem completely differently than traditional satellite internet which has has latency numbers measured in hundreds of milliseconds.

The latency numbers due to the laws of physics through space are lower than the latency numbers due to the laws of physics through fiber when talking about reasonable distances (e.g. new york to london stock exchanges).
Light travels faster in space than fiber. SpaceX's satellites (unlike existing constellations) are low enough that that benefit makes up for the small of extra distance.

To expand on this further, current "satellite internet" offerings are through the use of geostationary satellites 22,236 mi above the equator. The latency to the satellite and back to earth, plus whatever the latency is to get to wherever you are actually trying to go, is significant.
In contrast, the offering that SpaceX has just gotten approval for would use satellites that are about 342 mi above, and the network of satellites would be used to route the connection to a hop close to the destination.
The result of the above is latencies that are actually lower than even a direct fiber connection if the haul is long enough, because connections across Starlink would be at the speed of light (minus the amount of time it takes to process packets at each hop), and the speed at which data is transferred over fiber is some fraction of the speed of light.

For intercontinental routes, the satellite based connection might be noticeable faster even.

SpaceX's satellites are going to be in low-earth orbit, on the order of hundreds of miles -- you're thinking of traditional satellite internet which is typically in geosynchronous orbit 25,000 miles away. Depending on the number of hops, latency for these new constellations should be in the low milliseconds.
Since they're flying so low, they'll need thousands of satellites to provide wide coverage (instead of one super high satellite that can see half the earth at the same time), but they should be quite high performing.

Looking at latencies here [1], it’s not that bad. LEO orbit is under 1500 kilometers, adds a bit of lag, but may be compensated by a better route on the other end.
[1] https://www.google.ch/amp/s/www.nextbigfuture.com/2018/11/sp...

Most satellite internet deployments are in geostationary orbit (at 35,786km above the earth), which puts ground-to-satellite latency in the hundreds of milliseconds. Starlink will operate at just 550km, puting the theoretical latency at just 1.8ms. Even if the latency is 30x the theoretical, that's still in line with the latency of copper-cable deployment.

The satellites are in Low Earth orbit, not in geostationary orbit, thus signals have to travel at most 2,000 km, possibly only 400 km.

The Verge article claims 15ms latency, which honestly is really good, even if that's in addition to what you'd get if you were using a traditional internet connection.

TinTin A and TinTin B are at a similar altitude and achieve a reported 25 ms. That's a bit of an unexplained disconnect.

Isn't space based Internet really second rate due to latency?
Of course its great if there's no other Internet access, like rural areas, but it's a really poor service isn't it?
Happy to be corrected.

Last I read the Low Earth Orbit (LEO) systems will have fiber-like latency and gigabit speeds as they are ~200 mi away from Earth where Geosynchronous Earth Orbit (GEO) systems are 20K+ mi away.

That's definitely true for solutions in geostationary orbit where the signal needs to traverse 36000km twice between two ground stations, adding about 0.2 seconds delay for the request and again for the response.
SpaceX is planning a constellation in low earth orbit, that is supposed to route the traffic around the globe and down to a ground station near the point where the server is. That's saving the delay from having to go through an optically dense medium (fiber, speed of light is there about 200000km/s) and taking advantage of the much higher speed of light in vacuum.

I'm very skeptical that satellite-to-satellite connections have sufficient bandwidth to make that more effective than downlinking to base stations.

Why? (Genuinely curious if there is a reason, I'm not an expert on this)
Satellite-to-satellite connections are handled by pointing lasers at eachother. Ground-ground connections are handled by pointing lasers at eachother through a fiber. Fundamentally they seem pretty similar to me.

I wouldn't be skeptical about the bandwidth, I would be skeptical about the execution. There are existing inter-satellite links, but they are far lower bandwidth. You need much more precision and signal processing at higher bandwidths.

My understanding is that satellite-to-satellite is not legal.

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