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You're still sharing the medium (the sky), so at some point interference is going to be an issue. A quick search tells me the beams a satellite uses is measured

You're still sharing the medium (the sky), so at some point interference is going to be an issue. A quick search tells me the beams a satellite uses is measured in km, so you can only have one satellite serving several square km (you could have more channels of course).

Retric 2y ago
Let’s be pessimistic and say it’s ~25km^2 with current designs. Surface area of the earth is 510,064,472 km² so you estimate limits things to ~20 million satellites X however they can slice up the available spectrum. IE essentially unlimited satellites. As of September 2024 they have 6,371 operational satellites and ~ 4 million customers globally.
- CorrectHorseBat 2y ago
  How is that relevant? Adding satellites over the Pacific doesn't improve New York's service. The question is how dense of a population they can serve, not how many satellites Starlink could theoretically have.
  - Retric 2y ago
    The only way to add one satellite over NYC on average is to also add several satellites over the ocean and other low density parts of the earth. If you want low latency individual satellites must be in LEO which means they spend most of their time over water and low density bits of land. Which gets back to my original point where increasing the maximum density inherently reduces the average utilization of each satellite. There simply aren’t enough people living in Iowa etc to balance the east coast.
    - CorrectHorseBat 2y ago
      Sure, but my point was that there's a maximum density you can get which won't be enough for NYC or even a much less dense city.
      - Retric 2y ago
        The current network can handle 1 home per square km on average but averages over a very large area. So ~2,000 as many satellites and you can handle NYC’s population. It’s actually less than you expect because you can make use of satellites a hundred miles out to the sea, over the Hudson River, and even suburbs. And that’s before considering how few people would pick Starlink when they can use cheap fiber.
        CorrectHorseBat 2y ago
        Well no, that's my whole point. Because you're sharing the medium you'll get interference if multiple satellites service the same area. >And that’s before considering how few people would pick Starlink when they can use cheap fiber. Obviously we're talking about how dense an area Startlink can service on its own.
        Retric 2y ago
        > Because you're sharing the medium you'll get interference if multiple satellites service the same area I’m going to simplify because you seem to misunderstand what’s going on. Your eyes allow you to see a clear image of your surroundings because photons come from even slightly different angles aren’t interfering with each other. Starlink uses a phased array antenna to achieve a similar effect where satellites in different locations broadcasting on the same frequency can be clearly distinguished by two base stations physically next to each other. And similarly two different satellites can receive clear signals when two Starlink antennas are broadcasting when physically next to each other at the same instant. There’s physical limits and the phased array antenna in use are much worse than theoretically possible. But, the technology they are currently using really does scale vastly beyond what’s economical viable.
        CorrectHorseBat 2y ago
        I'm not at all misunderstanding what's going on, I know what phased array antennas are. It's not really like our eyes, we cannot perceive phase differences in light. A phased array is (at theoretically best) like a satellite dish which can move without actually having to physically move. >Starlink uses a phased array antenna to achieve a similar effect where satellites in different locations broadcasting on the same frequency can be clearly distinguished by two base stations physically next to each other If by next to each other you mean several km apart, yes. edit: Ok, I didn't think of that, if the satellites are far away from each other it'll work indeed since it's both the sender and receiver which have directivity. That indeed would make it scale better. Sure the technology can be improved, but there's only so much you can do at several hundreds of km distance and the sizes of antennas you have. Especially with mobile phones which are small and power limited I really don't see how it could work in anything but very low density areas.

Retric 2y ago

Let’s be pessimistic and say it’s ~25km^2 with current designs. Surface area of the earth is 510,064,472 km² so you estimate limits things to ~20 million satellites X however they can slice up the available spectrum. IE essentially unlimited satellites. As of September 2024 they have 6,371 operational satellites and ~ 4 million customers globally.

CorrectHorseBat 2y ago
How is that relevant? Adding satellites over the Pacific doesn't improve New York's service. The question is how dense of a population they can serve, not how many satellites Starlink could theoretically have.
- Retric 2y ago
  The only way to add one satellite over NYC on average is to also add several satellites over the ocean and other low density parts of the earth. If you want low latency individual satellites must be in LEO which means they spend most of their time over water and low density bits of land. Which gets back to my original point where increasing the maximum density inherently reduces the average utilization of each satellite. There simply aren’t enough people living in Iowa etc to balance the east coast.
  - CorrectHorseBat 2y ago
    Sure, but my point was that there's a maximum density you can get which won't be enough for NYC or even a much less dense city.
    - Retric 2y ago
      The current network can handle 1 home per square km on average but averages over a very large area. So ~2,000 as many satellites and you can handle NYC’s population. It’s actually less than you expect because you can make use of satellites a hundred miles out to the sea, over the Hudson River, and even suburbs. And that’s before considering how few people would pick Starlink when they can use cheap fiber.
      - CorrectHorseBat 2y ago
        Well no, that's my whole point. Because you're sharing the medium you'll get interference if multiple satellites service the same area. >And that’s before considering how few people would pick Starlink when they can use cheap fiber. Obviously we're talking about how dense an area Startlink can service on its own.
        Retric 2y ago
        > Because you're sharing the medium you'll get interference if multiple satellites service the same area I’m going to simplify because you seem to misunderstand what’s going on. Your eyes allow you to see a clear image of your surroundings because photons come from even slightly different angles aren’t interfering with each other. Starlink uses a phased array antenna to achieve a similar effect where satellites in different locations broadcasting on the same frequency can be clearly distinguished by two base stations physically next to each other. And similarly two different satellites can receive clear signals when two Starlink antennas are broadcasting when physically next to each other at the same instant. There’s physical limits and the phased array antenna in use are much worse than theoretically possible. But, the technology they are currently using really does scale vastly beyond what’s economical viable.
        CorrectHorseBat 2y ago
        I'm not at all misunderstanding what's going on, I know what phased array antennas are. It's not really like our eyes, we cannot perceive phase differences in light. A phased array is (at theoretically best) like a satellite dish which can move without actually having to physically move. >Starlink uses a phased array antenna to achieve a similar effect where satellites in different locations broadcasting on the same frequency can be clearly distinguished by two base stations physically next to each other If by next to each other you mean several km apart, yes. edit: Ok, I didn't think of that, if the satellites are far away from each other it'll work indeed since it's both the sender and receiver which have directivity. That indeed would make it scale better. Sure the technology can be improved, but there's only so much you can do at several hundreds of km distance and the sizes of antennas you have. Especially with mobile phones which are small and power limited I really don't see how it could work in anything but very low density areas.