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0 pointstzs4y ago0 comments

Starlink will not have enough bandwidth, even after the full constellation is deployed, to compete with even one cable company in a major metropolitan area. Starlink is designed for places where there is not a high customer density.

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serverholic4y ago

Do you have any resources to learn more about this?

tzsOP4y ago

Just random Googling. Google for things like "Starlink aggregate bandwidth" or "Starlink satellite bandwidth". Here's one article looking at this [1].

Each satellite is visible under idea circumstances from about 3% of the surface of the Earth at once. At an eventual 12000 satellites, that would mean 360 satellites would on average be visible from a given spot. The orbits are such that there will be much less coverage in the far north or far south and much more in between, so let's call it 1000 satellites on average visible in a given area that they will serve.

The next generation satellites are supposed to have 80 Gbps bandwidth to the ground. That's enough for 800 users simultaneously downloading. But most users most of the time are not going all out.

Let's try to estimate what average use is. Most Xfinity users have no trouble staying under their 1.2 TB/month cap. I've read somewhere that the average usage is only about 1/4 that. That would correspond to an average usage of around 1 Mbps, 1/100 of the speed of a Starlink connection. Using that, we can handle 80000 users per satellite, or 80000000 users for the 1000 satellites visible on average.

Taking into account the ground area in which a satellite is visible, we can work out the maximum ground density of customers at that usage level that stays within the bandwidth total. It works out to about 11 users/square mile (4.4 users/square kilometer).

In summary, Starlink should be able to deliver a decent 100 Mbps 100x oversold internet service in places where over the area visible from a satellite (about 7000000 square miles or 18000000 square kilometers) the customer density is under 11/square mile or 4.4/square kilometer.

The US population density is 94/square mile (36/square kilometer). California is 2.5x that, Florida and New York around 4x that.

The density it can support is probably actually a little lower than I got because I'm assuming that any satellite visible from your location can be used. My understanding is that the antenna is aimed in a good general direction at setup, and then uses a phased array to track satellites as they come and go. I'd expect that this limits you to satellites that are in front and not too far to the side of where the dish is pointed.

[1] https://www.techdirt.com/articles/20200928/09175145397/repor...

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