In any given place there are 3-4 Starlink satellites visible at a time. The bandwidth on each is somewhere in the 20 Gbps range.
So if you have 200 people using one satellite that’s no problem. 800 people using that whole cluster of visible satellites is also no problem. With 8000 simultaneous users you’re all down to 10 Mbps which is starting to get a bit limiting.
Each satellite covers an area about 15 miles across. About 100 square miles.
So… that works out to… something like 100 simultaneous users per square mile max.
That’s all back of the napkin math obviously… 1000 users packed into a small city surrounded by corn fields would be fine. 1000 users around every subway stop in NYC wouldn’t work even if the density is the same.
We've known how to efficiently broadcast TV programs to hundreds of millions of viewers simultaneously over satellite for decades now – in fact, that's how it all started :)
I wonder how hard it would be to add multicast capabilities to Starlink? Receivers could even cache popular content on a client side disk the way e.g. US satellite TV operators do for local ad insertion.
Good point about multicast - BT use it in the UK on their fibre/ADSL network to deliver live TV to their set-top boxes. I have never understood why it's not supported cross-ISP.
I believe it's very hard to implement across networks in a way that does not require core routers to become quite stateful and/or risks flooding parts of the network with multicast data nobody asked for.
There was a short conceptual revival of the multicast idea as an overlay network on top of unicast IP, under the banner of "content-addressable networks", but I haven't heard anything about that in a while.
So if you have 200 people using one satellite that’s no problem. 800 people using that whole cluster of visible satellites is also no problem. With 8000 simultaneous users you’re all down to 10 Mbps which is starting to get a bit limiting.
Each satellite covers an area about 15 miles across. About 100 square miles.
So… that works out to… something like 100 simultaneous users per square mile max.
That’s all back of the napkin math obviously… 1000 users packed into a small city surrounded by corn fields would be fine. 1000 users around every subway stop in NYC wouldn’t work even if the density is the same.