SpaceX’s Thursday Launch Enables Starlink’s New Satellite-to-Cellphone Internet Service

“SpaceX has launched 20 of its Starlink satellites up into Earth’s orbit, enabling direct-to-cellphone connectivity for subscribers anywhere on the planet,” reports the tech blog New Atlas.

That completes the constellation’s first orbital shell, following a …

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congress will do what they’re told. Midterms aren’t far and they wouldn’t want to go against Trump and get primaried.

The whole party is completely beholden to Trump. Don’t try and pretend they’d go against him. Many GOP senators have already stated they are not happy with some of Trumps “crash and burn” nominees and intended to not confirm them. I don’t think all GOP congress critters are toadying up to Trump now that the elections are over. Perhaps some of the GOP will form a new caucus – the Moderate GOP. Be careful with that encouragement – he already has a dozen kids. A number of which won’t even speak to him. Instead of “a number” why not just say “one”? Requires fewer letters and doesn’t involve weasel words. No, I can’t say I recall any such event. Unlike you and the rest of Elon’s fan club, I don’t use twitter, so naturally I’d have no reason to recall such an event. But more importantly, how does a baby decide whether to speak to him? Now there’s an lmao moment if I ever saw one. >”So that’s it? We’re all in touch anywhere now, regardless of where?” Well, yes and no. The *potential* exists for it. It depends on who your phone service provider is and IF you subscribe to what is likely going to be an expensive, optional add-on service. And then, likely only if you are outside. Presumably, although the signaling is the same, it is likely to be much weaker. Imagine your handset trying to reach hundreds of miles into space instead of just fractions of a mile to a nearby land tower I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots? Besides, if the satellites are at 540 km, that is about 100 times further away than a base station on the ground. Even if it is uninterrupted, perfect line of sight, doesn’t the signal strength decrease with the square (cube?) of the distance? That is, it is 10 000x (1 000 000x) weaker than for ground based networks. How can this be enough?? Not entirely, but you’re not entirely off either – which is likely why it’s limited to text-only with voice and other functions theoretically “coming later” and the low bandwidth.

It would be pointless to use an omnidirectional antenna. They’re likely using rather directional antennas and targeting specific areas (thus the “per beam” comment). So they can ramp up the power to their antenna on the satellite, and also they don’t face some of the other line-of-sight constraints that a terrestrial system does.

But still, selling this as something revolutionary is… overselling at best. 10 megabit data squirts that can barely carry text signals is “better than nothing” for extremely rural zones outside of cell network coverage, but it’s also unlikely they’ll be able to ramp it up without needing something more akin to the “so you mounted a pretty-honking-large antenna to your car, truck or RV” existing starlink service that costs $50/month for a less-than-dsl, high-latency setup. There’s simply going to be too much noise in the signal trying to catch the output of an unmodified cell phone, to say nothing of what will happen with the slightest atmospheric interference (same thing that causes problems for satellite TV services that are just receiving the downstream beam during a thunderstorm). Going to point this out, in relation to the part of your comment relating to the standard starlink service:This is from a rural area but – Personal experience that starlink gets ~200mbps, and the “mini” antennas are /very/ small. No issues in /any/ weather (rain, snow, whatever.) So all of what you mentioned (about the existing service – not the new cell based ones) appears to be incorrect. Oh, and ~20 ms to major internet sites. It would be pointless to use an omnidirectional antenna. They’re likely using rather directional antennas ….

They can use high-gain antennas and high-powered transmitters on the satellites, but if they really can pick up usable signals from 3-watt “unmodified cellphones” using “standard LTE/4G protocols” from 340 miles (540 km) away, that’s impressive. (Which also suggests that military technology for surveillance is probably even more advanced.) It would be pointless to use an omnidirectional antenna. They’re likely using rather directional antennas ….

They can use high-gain antennas and high-powered transmitters on the satellites, but if they really can pick up usable signals from 3-watt “unmodified cellphones” using “standard LTE/4G protocols” from 340 miles (540 km) away, that’s impressive. (Which also suggests that military technology for surveillance is probably even more advanced.) I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots?I’m not an expert on 4g but that makes no sense to me whatsoever. The purpose of hoisting those on a tower to begin with is, in addition to getting around things like trees and buildings, to work around the 12.2 mile limit that you inevitably deal with due to the curvature of the earth. And the whole point of using 600mhz spectrum is to go even further than that, up to about 45 miles in rural areas, or about 72km. I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots? I’m not an expert on 4g but that makes no sense to me whatsoever. The purpose of hoisting those on a tower to begin with is, in addition to getting around things like trees and buildings, to work around the 12.2 mile limit that you inevitably deal with due to the curvature of the earth. And the whole point of using 600mhz spectrum is to go even further than that, up to about 45 miles in rural areas, or about 72km. No, you clearly are not an expert. You are completely wrong. Mansplainer. While you were womansplaining that, had it not occurred to you that LTE already commonly goes well beyond 6km? That is why I asked my original question. Duh! And yet a simple googling would have revealed that it already goes well beyond this. I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots?I’m not an expert on 4g but that makes no sense to me whatsoever. The purpose of hoisting those on a tower to begin with is, in addition to getting around things like trees and buildings, to work around the 12.2 mile limit that you inevitably deal with due to the curvature of the earth. And the whole point of using 600mhz spectrum is to go even further than that, up to about 45 miles in rural areas, or about 72km.Low-band LTE follows the curvature of the earth better. Your longer-range cell sites are likely to be 900 MHz or lower. That’s why they were in a hurry to drop 3G to free up those critical frequency bands.That said, there is a limit that has nothing to do with line-of-sight, and that second limit exists because LTE towers try to time things so that each cell phone occupies a single time slice at the tower for both sending and receiving data. To achieve this, the cell phone starts sending data ahead of that time window so that it will be received by the tower during that time slot. It determines the amount of delay after a handshake with the tower that results in the tower providing a timing advance value. Each increment of that value moves the cell phone’s transmission window earlier by about 0.52 microseconds. The anti-delay/premature transmission amount therefore gets larger the farther away the phone is. And unfortunately, that value is only 11 bits long, which probably seemed like a good idea at the time. :-DAs a result of that limit, the official upper limit for LTE, according to the spec, is 100 km, and even StarLink LEO satellites are at several times that limit. More than that, and you won’t be able to compensate for the latency, and the phone’s signal will overlap with some other phone’s time slot.But here’s the thing, the satellites *know* that they’re in orbit. Presumably they set a timing advance of zero for the ground position directly below the satellite and go from there. As long as the satellite covers a ground area with no more than a 100 km radius per cell, and as long as it allocates two time slices per cell phone — one for the transmit window and one for the receive window — then the rest is just software.I *think*. That said, this is mostly just me thinking about it off the top of my head. I’m not an RF engineer, and I haven’t dealt with any of this directly, so take that with a huge grain of salt. :-)There’s also a theoretical upper limit to speed because of doppler shift, but I’m assuming they’re compensating for that as needed, and given that the satellites are moving mostly sideways relative to you rather than towards or away from you, I’m not going to do the trig to figure out how bad the doppler shift would be, but that part might not even be outside the spec limit as long as they have enough birds to have one nearly overhead covering a narrow enough arc.Anyway, just thinking out loud, and feel free to correct me if I’m wrong on the finer points here, but I’m pretty sure that’s the gist, anyway. I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots?I’m not an expert on 4g but that makes no sense to me whatsoever. The purpose of hoisting those on a tower to begin with is, in addition to getting around things like trees and buildings, to work around the 12.2 mile limit that you inevitably deal with due to the curvature of the earth. And the whole point of using 600mhz spectrum is to go even further than that, up to about 45 miles in rural areas, or about 72km. I thought the timeslot limits in cell phone network limited the range to something like 3 km, 6 km if you used the double amount of time slots? I’m not an expert on 4g but that makes no sense to me whatsoever. The purpose of hoisting those on a tower to begin with is, in addition to getting around things like trees and buildings, to work around the 12.2 mile limit that you inevitably deal with due to the curvature of the earth. And the whole point of using 600mhz spectrum is to go even further than that, up to about 45 miles in rural areas, or about 72km. Low-band LTE follows the curvature of the earth better. Your longer-range cell sites are likely to be 900 MHz or lower. That’s why they were in a hurry to drop 3G to free up those critical frequency bands. That said, there is a limit that has nothing to do with line-of-sight, and that second limit exists because LTE towers try to time things so that each cell phone occupies a single time slice at the tower for both sending and receiving data. To achieve this, the cell phone starts sending data ahead of that time window so that it will be received by the tower during that time slot. It determines the amount of delay after a handshake with the tower that results in the tower providing a timing advance value. Each increment of that value moves the cell phone’s transmission window earlier by about 0.52 microseconds. The anti-delay/premature transmission amount therefore gets larger the farther away the phone is. And unfortunately, that value is only 11 bits long, which probably seemed like a good idea at the time. 😀 As a result of that limit, the official upper limit for LTE, according to the spec, is 100 km, and even StarLink LEO satellites are at several times that limit. More than that, and you won’t be able to compensate for the latency, and the phone’s signal will overlap with some other phone’s time slot. But here’s the thing, the satellites *know* that they’re in orbit. Presumably they set a timing advance of zero for the ground position directly below the satellite and go from there. As long as the satellite covers a ground area with no more than a 100 km radius per cell, and as long as it allocates two time slices per cell phone — one for the transmit window and one for the receive window — then the rest is just software. I *think*. That said, this is mostly just me thinking about it off the top of my head. I’m not an RF engineer, and I haven’t dealt with any of this directly, so take that with a huge grain of salt. 🙂 There’s also a theoretical upper limit to speed because of doppler shift, but I’m assuming they’re compensating for that as needed, and given that the satellites are moving mostly sideways relative to you rather than towards or away from you, I’m not going to do the trig to figure out how bad the doppler shift would be, but that part might not even be outside the spec limit as long as they have enough birds to have one nearly overhead covering a narrow enough arc. Anyway, just thinking out loud, and feel free to correct me if I’m wrong on the finer points here, but I’m pretty sure that’s the gist, anyway. o|= Nowhere to run to, baby – nowhere to hide. o|= It’s ‘handy’ to have massive MIC contracts. They’ll try to set the 5G satellites on fire. Too bad for the argument that using a phone on a plane will somehow interfere with equipment on the ground. Now these signals are coming from satellites which are much higher.Using a cell phone on a plane just plain won’t work unless you’re flying low and slow. The cell towers are aimed so that they don’t cover anything above about 10,000 feet until you’re so far out that you are likely beyond the 100 km limit for LTE (which has to do with the way time slots work; see my post elsewhere in this thread for details).Additionally, although LTE by default can support speeds up to 220 MPH in all bands (and up to 310 MPH in specific bands), it is only efficient up to about 75 MPH. Th Too bad for the argument that using a phone on a plane will somehow interfere with equipment on the ground. Now these signals are coming from satellites which are much higher. Using a cell phone on a plane just plain won’t work unless you’re flying low and slow. The cell towers are aimed so that they don’t cover anything above about 10,000 feet until you’re so far out that you are likely beyond the 100 km limit for LTE (which has to do with the way time slots work; see my post elsewhere in this thread for details). Additionally, although LTE by default can support speeds up to 220 MPH in all bands (and up to 310 MPH in specific bands), it is only efficient up to about 75 MPH. Th There may be more comments in this discussion. Without JavaScript enabled, you might want to turn on Classic Discussion System in your preferences instead. Google Says Its New PaliGemma 2 AI Models Can Identify Emotions. Should We Be Worried? Does the New ‘Y2K’ Comedy/Disaster/Horror Film Give the ’90s the Ending It Deserved? To be or not to be, that is the bottom line.

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