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Comment by portillo | Hacker News Reader

You could provide home broadband using a wireless, mobile-network like system if you wanted to.

It is not happening because it's very difficult to do that with the spectrum allocated for mobile services. A network of towers can provide higher capacity densities than what SpaceX's 30k satellite systems will be able to.

In big cities, they will fall very sort of the capacity required. The current 4,409 satellite proposal has beams of ~700 Mbps, and each of those covers a surface larger than the whole NYC metropolitan area. The capacity scales linearly with the number of satellites in line-of-sight (LoS). Right now, with the 4,409 satellite system you can have ~40 satellites in LoS, so they can provide ~28 Gbps of throughput to the whole city. Even with 30k satellites, they will only be able to provide ~196 Gbps. That is not enough to offer any uncapped data plan.

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> You could provide home broadband using a wireless, mobile-network like system if you wanted to.

Why do you continue referencing one of the most densely populated cities in the world as the unit of measure? This is for un-served and under-served areas which is half the globe. Of course they aren't building this to displace NYC's current ISPs. They clearly ran financials before investing... you seem like you're just trying to find a reason to say it's stupid without bothering to consider that someone smarter than you MIGHT have done a little research before spending a couple billion dollars.

My PhD research is on how to use space and aerial networks to serve the unconnected and undeserved. I have been studying these networks (and things like Google's loon, mmwave, etc) for the last 4 years. I have simulated these networks in detail, assessed their capabilities, and ran a lot of financials myself.

According to my analyses, there needs to be a disruptive change in how we receive broadband Internet to close the business case (that's why I keep talking about Displacing ISPs). The unconnected and undeserved broadband market plays great in the US and Canada, but in the rest of the world, there is simply not such a market. At best, you are going to try to provide backhauk for a cell phone network or some other kind of access point. The whole 3B of unconnected people rethoric is very slim. Those people can afford to pay very little every month for connectivity, so it's very hard to make money out of it (even to offset your marginal costs).

In terms of performance, there are diminishing returns on each extra satellite that you launch. The ones already up there are already satisfying a lot of the demand, so each newly launched satellite is active for a shorter and shorter percentage of time.

Starlink is a (in my opinion) very oversized system. I do not think they will launch the full 4,409 constellation (as it stands today), and I am pretty confident they will not launch a 30,000 satellite constellation.

Finally, LEO networks are not the most cost effective space networks. GEO HTS and MEO networks have lower CAPEX/GB.

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