Comment by mbreese
6 hours ago
All satellite based internet access works the same way… (mostly)
1) you send a signal to the satellite
2) the satellite relays the signal down to a ground station
3) from here your packets go out on the Internet like any other ISP
The answer then goes in reverse: back to the ground station, up to the satellite and down to your dish.
Starlink’s special sauce is the low earth orbit. Older satellite internet companies operated in geosynchronous orbit. This meant they only needed one or two satellites to cover a large area. You also only needed a small number of ground stations. The satellite needs to be able to see your dish and the ground station at the same time. But this is very high up, so latency was horrible (the distance up and down before the packet even hits the internet). Bandwidth was also limited, but much less of an issue.
With low earth orbits, you have great latency. But, because you still need to be able to see the ground station and the customer’s dish, this means that you need more ground stations. This is just geometry.
Starlink adds one more feature that is relevant here - direct satellite to satellite communication. Instead of the signal going from:
Customer - satellite - ground station - internet
The signal can go from:
customer - satellite A - satellite B - ground station - internet.
This later setup might be what you were thinking about. You still want to limit the number of hops from satellite to satellite you have (latency again), but this should make the service more resilient to the loss of a single ground station.
> Starlink’s special sauce is the low earth orbit.
Arguably Starlink's special sauce is quantity of satellites and massively higher bandwidths combined with high-gain, electronically steered beams on both sides (i.e. terminal and satellite).
None of these are net-new as technologies: We've had LEO based telecommunications satellites for over two decades now (Iridium and Globalstar, the former of which even has in-space forwarding as well), as well as directional beams on both sides, but rarely all in one system and never at this scale.
In my opinion, the quantity of satellites needed is a function of the height of the satellites. You only need a large constellation because they are moving so fast relative to the earth. This means that each satellite can only see a limited arc at a time. So, in order to cover a large enough area, you have to have multiple satellites following after each other.
The phased array antenna is also a function of this. Each satellite is moving so much that you need to have an antenna following the satellite across the sky.
So, once Starlink decided to have a low earth orbiting constellation (for better latency and bandwidth), the other features (quantity and a steerable antenna) became requirements to have a functional system.
Altitude does impose a lower bound for the number required for global coverage but they have much, much more than geometrically needed. Iridium gets by with about 70 and is only marginally higher.
As for steered terminals, you actually only really need these once you have more than one satellite visible in the sky at the same time. Without that, they’re purely a power efficiency feature.
Is that true though? 5g is significantly faster than starlink
yes it's true that starlink has shitloads of satellites
What you are calling 'internet' is the land based backbone that's connecting to the 'rest of the internet'. The term is thus relative. Now of course there is next to no servers directly on the sate to sate network save for a few companies with special contracts. But with the AI sate halo there will inevitably be other server sate.
but there are other LEO Internet services, like Iridium and Globalstar that just don't compare, like 100x slower at 5x monthly price for 1000x less data.
"because LEO" don't explain why Starlink is like million times cheaper and faster than competitors while singlehandedly being reponsible for like 75% of man-made objects in space currently and past.
If you are stuck on a ship in a typhoon, iridium is precisely the system you want to be using.