JF Mezei wrote on Tue, 20 Nov 2018
18:34:08 -0500:

Video showing the updated Starlink config.

https://www.youtube.com/watch?v=QEIUdMiColU

The large constellation is at a 53° inclination so of no use service the
Arctic. (from 550km altitude, footprint not that big).


Note that in the full system there are satellites in polar orbits.


There appears to be a small constallation with polar orbits. Whether
they provide constant converage is not known. (the vodeo doesn't focus
on it as it appear to be a small part of the constellation).


The video doesn't talk about it because the video is largely talking
about 'first phase', which is just the 7500 or so satellites in lower
orbits. Why do you think they would bother to add polar satellites if
they don't provide coverage?


The "sales pitch" appears to be aimed at selling capacity between major
cities (such as between London and Los Angeles) as opposed to
connecting retail customers to the Internet.


What 'sales pitch'? You mean the examples mentioned in the video?


Latency may be low enough at one point in time, but consider the added
lag while links are renegotiated between satellite leaving and satellite
arriving, each with their own links to other satellites.


Latency stays low.


The renegotiation gaps may be acceptable for retail (as they are for
mobile phones when in a car/train), but not sure good enough for commercial.


Why would they be different?


Also, fibre has far more capacity than a laser. Not only can fibre
support simulteneous wavelengths, but there are a lot of strands in a
trans-atlantic cable for instance


Lasers are faster.


It's possible the satellite lasers will have multiple wavelengths, but
not likely to have multiple beams since aim would become difficult
between constantly moving staellites.


Did you watch your own cite? Rates of change are low. The current
design can handle 50% of the entire backhaul load of the current
internet and around 10% of the uplink load from even very dense target
areas.


(the north-south links between sateliotes in same orbital plane would be
stable, but those east-west links between staellites in different
orbital planes would need sophisticated tracking and have varying distances.


It's not THAT sophisticated. Rate of change is slow.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn