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Each satellite has a bandwidth limit and can cover a certain area (more satellites per area close to the poles). It's not that they "can't" it's that they won't

by coryrc 6y ago

Each satellite has a bandwidth limit and can cover a certain area (more satellites per area close to the poles). It's not that they "can't" it's that they won't be able to be competitive in most suburbs, at least not at this time.

mlyle 6y ago
Basically, fixed wireless should win every time over satellite when fixed wireless is possible. Less path loss means more bits per Hz of bandwidth. Less exotic equipment (no beam-steering). More opportunity for densification to increase capacity. The possibility of wired backhaul. It's only when population density is low, or fill-in for areas where towers don't quite reach, or for specialized uses (military, redundancy in access, some mobile use cases, some financial use cases with reduced latency) --- that satellite is a clear win. Starlink can have a plenty big business addressing the most rural and fill-in, though.
- zamadatix 6y ago
  Fixed wireless is plagued by line of site. The other problems haven't really been an issue for Starlink, even for being in the early phases, it's really just the density issue that bites it.
  - mlyle 6y ago
    Line of sight is a bit of a pain. So is needing sky in all directions to 10-20 degrees of elevation. Satellite is great for A) where it's not worth putting up towers to reach just a few residents, and B) filling in where there's little holes in tower coverage. (This is what I tried to say in the comment you're replying to). > The other problems haven't really been an issue for Starlink, even for being in the early phases, it's really just the density issue that bites it. Capital costs are high per simultaneous user served in an area. Densification is hard. Spectral efficiency is the key figure of merit (how many bits you get to users per limited bit of radio spectrum). That is, the things I mention *are* the reasons for the "density issue".
    - Retric 6y ago
      Spectrum is different with satellites as it’s using directional antenna. In theory you can have nearly arbitrary satellite density depending on efficiency. The only effective limit is the user density you’re aiming to support.
      - mlyle 6y ago
        Fixed wireless uses directional antennas, too. Towers can have sector antennae, and you can have multiple towers servicing an area, too. (Indeed, small LEO satellites' ability to spot beam is limited, but sectors on fixed wireless can provide a -lot- of densification).
        Retric 6y ago
        Directional antennas on the ground are a much higher risk from obstructions. Multipath propagation is essential for large wireless networks without building giant towers everywhere.
        mlyle 6y ago
        > Directional antennas on the ground are a much higher risk from obstructions. Giant towers / hillsides for the central point; small towers or rooftops for the other end. Between two hills over my suburb, you can see 80%+ of houses. If your point is that this doesn't work well for dense cities: you're right, but it breaks down at a higher population density than satellite does. Relying upon multipath and diffraction can work to get moderate quality LTE service everywhere, but in general this is not what WISPs are doing, because it doesn't work. (And in any case, MIMO + multipath are friends, too, which provides its own densification, and sector antennae are effective, too).
        Retric 6y ago
        This is why WISPs are so location specific. With the right geography, population density, etc it can work but we don’t have these companies going nationwide.

by coryrc 6y ago

mlyle 6y ago

Basically, fixed wireless should win every time over satellite when fixed wireless is possible. Less path loss means more bits per Hz of bandwidth. Less exotic equipment (no beam-steering). More opportunity for densification to increase capacity. The possibility of wired backhaul. It's only when population density is low, or fill-in for areas where towers don't quite reach, or for specialized uses (military, redundancy in access, some mobile use cases, some financial use cases with reduced latency) --- that satellite is a clear win. Starlink can have a plenty big business addressing the most rural and fill-in, though.

zamadatix 6y ago
Fixed wireless is plagued by line of site. The other problems haven't really been an issue for Starlink, even for being in the early phases, it's really just the density issue that bites it.
- mlyle 6y ago
  Line of sight is a bit of a pain. So is needing sky in all directions to 10-20 degrees of elevation. Satellite is great for A) where it's not worth putting up towers to reach just a few residents, and B) filling in where there's little holes in tower coverage. (This is what I tried to say in the comment you're replying to). > The other problems haven't really been an issue for Starlink, even for being in the early phases, it's really just the density issue that bites it. Capital costs are high per simultaneous user served in an area. Densification is hard. Spectral efficiency is the key figure of merit (how many bits you get to users per limited bit of radio spectrum). That is, the things I mention *are* the reasons for the "density issue".
  - Retric 6y ago
    Spectrum is different with satellites as it’s using directional antenna. In theory you can have nearly arbitrary satellite density depending on efficiency. The only effective limit is the user density you’re aiming to support.
    - mlyle 6y ago
      Fixed wireless uses directional antennas, too. Towers can have sector antennae, and you can have multiple towers servicing an area, too. (Indeed, small LEO satellites' ability to spot beam is limited, but sectors on fixed wireless can provide a -lot- of densification).
      - Retric 6y ago
        Directional antennas on the ground are a much higher risk from obstructions. Multipath propagation is essential for large wireless networks without building giant towers everywhere.
        mlyle 6y ago
        > Directional antennas on the ground are a much higher risk from obstructions. Giant towers / hillsides for the central point; small towers or rooftops for the other end. Between two hills over my suburb, you can see 80%+ of houses. If your point is that this doesn't work well for dense cities: you're right, but it breaks down at a higher population density than satellite does. Relying upon multipath and diffraction can work to get moderate quality LTE service everywhere, but in general this is not what WISPs are doing, because it doesn't work. (And in any case, MIMO + multipath are friends, too, which provides its own densification, and sector antennae are effective, too).
        Retric 6y ago
        This is why WISPs are so location specific. With the right geography, population density, etc it can work but we don’t have these companies going nationwide.