Between one transmitter and receiver. Starlink is designed to cheat Shannon by utilizing SDMA on a truly massive scale. Every antenna in the system, both on the satellites and on the ground stations, is a large phased-array antenna, capable of simultaneously emitting different signals on the same wavelength in different directions, and capable of discriminating between multiple different signals on the same wavelength that come from different directions.
This is how Starlink intends to push so much throughput over just ~50 GHz of bandwidth. Not by pushing more bits per hz per link, but by filling the sky with hundreds of simultaneously visible satellites, and having each of them to all use all of the available spectrum at the same time on every link between any of them and any of the ground stations.
Phased arrays aren't magic. The directivity of the beam scales logarithmically with array size / element count. The limitations are such that you should think of it as being able to send Nebraska one signal while you send Kansas a different one. You can't get much more specific than that.
Elon has been very explicit about starlink never being competitive vs telcos in urban areas.
Phased arrays are not magic, but they are better than you make them sound like. When the directivity of the beam scales logarithmically with the element count, it just means you need a whole lot of elements.
The beam sizes are in the FCC filings, and they will be able to fully re-use the frequencies for ground stations that are >20km apart. (Not with the same satellite, you want adjacent beam spots on the ground to come from different satellites, but with literally hundreds above you at any time, that's not a problem.) Availability of bandwidth does not really limit them until the satellite counts are up to really hilarious numbers.
The aggregate throughput numbers in the paper you linked are correct, for the initial FCC filing. Since then they have multiplied the size of the constellation by ~7 and the throughput per satellite by ~3 (for 2.0 satellites). (ISL's are still missing, though.)
Between one transmitter and receiver. Starlink is designed to cheat Shannon by utilizing SDMA on a truly massive scale. Every antenna in the system, both on the satellites and on the ground stations, is a large phased-array antenna, capable of simultaneously emitting different signals on the same wavelength in different directions, and capable of discriminating between multiple different signals on the same wavelength that come from different directions.
This is how Starlink intends to push so much throughput over just ~50 GHz of bandwidth. Not by pushing more bits per hz per link, but by filling the sky with hundreds of simultaneously visible satellites, and having each of them to all use all of the available spectrum at the same time on every link between any of them and any of the ground stations.