| ▲ | daRealDodo 18 hours ago |
| Can anyone explain how upload would work? How can an unmodified cellphone upload data to a satellite? |
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| ▲ | emusan 16 hours ago | parent | next [-] |
| There are a few factors that make this possible: 1. As others have pointed out, the link budget (how much energy loss a particular radio link can handle before it is broken) for D2C satellites assumes a nearly direct line of sight from your handset to the satellite. This is much easier to achieve with satellites in space than it is with traditional cell towers that might have numerous walls/buildings in the way. 2. The D2C satellites use massive phased array antennas that are able to point a very narrow beam very accurately to the ground. This provides a substantial amount of antenna gain that further helps the link budget. The gain from the antennas allows the satellites to pick up even relatively weak signals from a handset. There are other tricks as well, but these account for the largest differences. Of course, doppler gets in the way, but it is a solvable problem. |
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| ▲ | bilsbie 15 hours ago | parent [-] | | So the satellite can point a narrow beam. How does it handle multiple connections. Can it aim 1000s of beams at once? | | |
| ▲ | pbmonster 6 hours ago | parent | next [-] | | In theory, yes. Phased arrays can steer as many independent beams as the connected electronics support. I real life, it's probably going to be dozens or maybe hundreds of beams. | |
| ▲ | kumarvvr 11 hours ago | parent | prev [-] | | I guess the narrow beam, covers quite a bit of area on earth. I guess the "narrow" in the current context is the beam widening to hundreds of miles on earth. | | |
| ▲ | lutorm 6 hours ago | parent [-] | | IIRC the current Starlink beams are of order 10 miles on the ground. So much narrower than you guess. |
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| ▲ | mbreese 18 hours ago | parent | prev | next [-] |
| My thinking is that you can think of Starlink satellites as LTE towers that just happen to be ~350 miles away from your phone. It happens to work because while they are far away, the satellites have a very clear line of sight (directly down) with few (no) obstacles. The complication is that the base stations will be moving much more rapidly than traditional terrestrial towers. |
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| ▲ | maccam94 18 hours ago | parent | prev | next [-] |
| very slowly, with the radio at maximum power, and no obstructions |
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| ▲ | silisili 16 hours ago | parent [-] | | Yeah, this is going to decimate your battery life. It's great to have in an emergency, don't get me wrong, but I'd probably leave data off otherwise when out remote. |
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| ▲ | mise_en_place 18 hours ago | parent | prev [-] |
| Your cell phone uses the nearest base station, the base station will handover to the satellite infra. |
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| ▲ | Gare 18 hours ago | parent | next [-] | | Why do you need satellite if you can connect to a base station? This makes no sense. No, they claim direct phone to satellite link. | |
| ▲ | rblatz 18 hours ago | parent | prev | next [-] | | No, that’s just satellite backhaul for a cell tower. That’s not hard, but also typically if you can get power to a base station you can run fiber along the same poles the power runs on. This is direct from handset to satellite, it’s clearly explained in the link. | | |
| ▲ | Gare 18 hours ago | parent [-] | | > That’s not hard, but also typically if you can get power to a base station you can run fiber along the same poles the power runs on. Or a directional microwave link to the next station in sight. |
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| ▲ | navigate8310 18 hours ago | parent | prev [-] | | Aren't those satellites going to generate simulated cell tower signals so you won't require any modification whatsoever? |
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