Starlink's problem is going to be that most profitable areas are better served by terrestrial LTE/5G, leaving only truly remote areas that are low density enough. But not many people live there...
Spectral bandwidth doesn't matter so much with beamforming with reasonably narrow beams. At least not until you get to a lot of satellites overhead at once. Dishy probably obtains a beam ~3 degrees wide; there's a lot of 3x3 degree sectors in the sky.
Similarly, the ground "cells" are 300 sq km; there's a lot of these in view of the satellite.
> Starlink's problem is going to be that most profitable areas are better served by terrestrial LTE/5G
Yup, for the most part I agree. Still, there is a pretty large rural population.
Sure, how much data you can exchange per satellite is roughly proportional to the bandwidth.
Increasing bandwidth or increasing satellites increases data rate.
> it's why SpaceX pays so much on legal fees for fcc filings
Note that a whole lot of the paper that goes to the FCC relates to the FCC's statutory authority over space debris and constellation licensing.
Well, sure. It has a multiplicative effect with number of satellites on throughput. Not to mention the proxy warfare they've endured from other constellation vendors through the FCC.
The big point which I responded to was there was a claim that adding more satellites doesn't add throughput ("Do cheap launches help")-- that one could be purely spectrum limited and not benefit from additional satellites. Directional antennas make this not true for any reasonable number of satellites.
If you use a diameter for a circle area, you need to divide by 4, to get like ~7. I was just going to do 3*3 = 9.
> It looks like Starlink has 7 GHz total downlink bandwidth from satellite to customers. A cell may be ~300 sq km, but no way you can pipe all that bandwidth in adjacent cells due to interference
Both the downlink and the uplink are directional. Yes, there's some power lost in side lobes, but..
So, if you have multiple satellites overhead, you can have a mosaic pattern where satellite A illuminates a hex, and then other satellites illuminate its neighbors. And even though some energy spills over, it's strongly rejected by the receivers because it's coming from the completely wrong direction.
> How many people live in places with fewer than a few people/km^2?
In addition to the incorrect pessimism about downlink bandwidth (also, one should expect ~5bits/Hz)... You're not taking into account any reasonable capacity factor, and you're assuming each service is one person. You're also assuming that you sell through to 100% of the populace and there's no one in the cell served by other technologies. If 95% of a suburban area can get FTTH, cable, or reasonable LTE, that still leaves 5% as possible customers for Starlink to fill in.
> Only Alaska averages below that in the US.
OK, but people are concentrated into cities, leaving a whole lot of land area with concentrations below this even in states with much higher average population density.
Yes, obtained by channelization and OFDM, not by limiting modulation.
Reverse engineering of the 10 to 12.7GHz band has shown a mixture of 16-QAM and 64-QAM frames. There's a bit of periodic 4-QAM too, which seems to be for acquisition and synchronization.
Even 16-QAM can climb basically to 5 bits/Hz.
I think you meant 7 Gbps; that only works if the satellite itself has that much inbound, which may not be the case if the satellites around (for sat-to-sat links) it or the base station that it sees are maxed out.
> which may not be the case if the satellites around (for sat-to-sat links)
No real sat-to-sat links yet. The exact specifications aren't disclosed, but they'll likely be 100gbps symmetric links.
> the base station that it sees are maxed out.
You can expect spectral efficiency for the uplinks to be better because of big antennas, and for them to be provisioned with no problem illuminating all the satellites overhead.
> which effectively halve the available bandwidth
I disagree (and I'm not sure where this idea is coming from-- do you think they use the same spectrum or something?) I think they effectively "add" bandwidth for the system by allowing satellites that do not have saturated uplinks to "share" capacity. E.g. a satellite which is mostly over the ocean but can see a ground station can now be more useful.
Yes, sat-to-sat enables new use cases. But it also has other effects.
All the satellites above me have an uplink from a ground station.
Also, satellites above ocean with few people in their footprint can see my uplink but can't use it effectively, because they don't have many users in their footprint (possibly none, because of elevation angle restrictions).
If we have satellite-to-satellite links, then those satellites above ocean can share their bandwidth with satellites above me. Therefore, real system capacity goes up.
Assuming that ground stations are upgraded as the size of the constellation grows-- they're strongly directional. Their throughput is the uplink bandwidth * the spectral efficiency * the number of satellites within LOS of an uplink ground station. Intersatellite links let you use more of this throughput without it going unused and "spoiling"-- that's the main point.
In the current era of phased array antenna prices falling sharply, and assuming they're willing to go for a folding antenna, I think they could probably easily get a 10x antenna area boost without much extra cost.
I don't get the question. Do costs matter when revenue is limited?
Of course they matter. They matter even more the more limited is the potential revenue.
And just because Rosenworcel was appointed by Obama instead of Biden doesn’t mean she’s not a loyal part of the Biden administration.
why not? seems like they should have had to
Again wrong. SpaceX in fact has already appealed the decision to the full Commission. But the chairwoman can legally just sit on that petition for a very long time. And SpaceX can’t sue in court until the FCC makes a decision on that, since you have to exhaust administrative remedies before going to court.
I'm not sure why you're calling me a leftist or what politics have anything to do with this topic. The FCC has been unusually nice to SpaceX over the years to the point where virtually all other satellite companies were suing because they were being given preferential treatment on things that the FCC never allowed before. Now that the playing field is fair (well, not quite since nobody else in the space got RDOF money), SpaceX isn't so magical.
ajit pai is the one you should be blaming for giving it to them in the first place when it was obvious to anyone with satellite knowledge that they could not offer that service to the amount of people they said in the time they claimed.
That’s not quite right. They can take it if they conclude you will not meet the target. Ups and downs on the way there are totally fine under the rules.
Starlink can scale dramatically just by launching new satellites. The FCC is keen on stopping that too, refusing to approve all of Starlink’s satellite launch proposals and instead making them slow walk their growth.
In addition to hating Musk, the White House thinks fiber to the home is like rural electrification. Starlink, by providing very much good-enough universal service (though they can scale up to gigabit speeds, it’s just a matter of how many satellites they have), is threatening to undermine political support for spending money on fiber buildouts.
It’s not some crazy conspiracy. This is the whole point of winning elections. The people in charge of tech policy in this admin want universal fiber service. You don’t get tens of billions from Congress every year for that unless there’s public demand for it. Starlink would undermine that demand despite not being good enough to replace universal fiber service, in the eyes of the administration.
Also you’re free to look up how Starlink’s launch proposals have been slow rolled at the FCC. You can also look at the Republican Commissioner’s statements on the revocation of Starlink’s RDOF award.
this excludes a lot of the population outright since they don't have a payment plan for lower income users to afford it.
the FCC's letter says that they determined they could not deploy a system of the size they promised in the timeframe they promised. whether you agree with it or not, that assertion has been correct so far.
And the letter of course says that. That doesn’t mean it’s their real motive or a correct conclusion.
Do you have a source for them burning money at a pace that requires starship in the near future?
Looking in from the outside, their amount of falcon launches don't reflect that.
https://spaceflightnow.com/2023/02/26/spacex-unveils-first-b...
I didn't expect that, since the company makes a lot of money. I guess they also invest a lot.
Anyway, thinks for the info update!
starlink is a project worth billions with years of planning, there's no fake it till you make it in that league
do you seriously think this is something they stumbled onto? they are rising the prices because they can, it's not a non-profit.
even the article mentions that the service is within stated expectations.
Starlink is still not profitable. Musk and Shotwell have hinted at this or directly said it. It requires an immense amount of money to fund the engineering, support, and launches to keep even the current number of subscribers they have.
While Starlink is "successful" by your definition, you have both Oneweb and TeleSat's lightspeed both being relative failures. This isn't because they were worse systems. In fact, Telesat's was supposed to have the best bandwidth economics. But it failed largely because it didn't get the funding SX gets due to Musk, and they realized the economics of a LEO constellation are nearly impossible to sustain.
What you're seeing right now is an ISP that's akin to Uber or Lyft. Are they profitable? No, but they're around and they're big names. Your rides are subsidized from VC money hoping one or the other will lose and the other can raise prices.
Starlink is raising prices because they have to. Not because "they can". They are decreasing prices in unfilled areas just to use the capacity that is otherwise completely stranded. Once those areas fill, wash, rinse, repeat.
The honeymoon phase of starlink is over. in the best case scenario with starship they can add capacity much cheaper. but even the business case for that is going to be hard to close given the amount of money they're already burning.