Re: [Starlink] Starlink Internet Speeds Could Skyrocket to 2 Gigabits Per Second, SpaceX President Says

[Ulrich Speidel <u.speidel@auckland.ac.nz>]

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Right now, Starlink have reached capacity in quite a number of places.

The availability map on Starlink's home page shows that Starlink is 
"sold out" in many places, including London, Manila, Rio de Janeiro, 
Seattle, Portland, Sacramento (California), Edmonton, San Diego, Austin 
(Texas), Mexico City, Guadalajara, Brisbane, Accra, Lagos, Nairobi, 
Lusaka, Harare, and many more:

https://www.starlink.com/us/map

This isn't surprising given the fact that Dishys to date only use 
Ku-band, there's only 2 GHz of it for user downlink, and you can't use 
the same beam frequency in adjacent cells.

SpaceX have a modification application before the FCC that, if 
successful, would allow them to:

  * Up power flux density on the ground. This'd allow satellites to
    transmit with higher power. Note that none of the current beam
    transmitters on the satellites have sufficient EIRP to hit the
    current PFD limits across the entire Ku-band. But the Gen. 2 ones
    are supposedly only by a factor of about 2.7 off, so with Starship
    able to carry heavier sats, there might be room for a bit of growth.
  * Use satellites down to 20 deg above the horizon instead of the
    current 25 deg (this mightn't look like much, but if my calculations
    aren't wrong, means that they'd see about 43% more of the orbital
    sphere with that increase alone).

SpaceX have tried for a long time to get into lower orbital height 
shells. This makes sense from their perspective: Each satellite's beam 
footprint becomes smaller, which makes frequency re-use easier. Path 
loss decreases, and a ground station sees a smaller fraction of 
satellites in that shell, so they can argue that since the ground now 
sees transmissions from fewer satellites, EPFD limits are less critical, 
which allows them to up power. Makes for a couple of bits more per 
symbol perhaps. Latency goes down a little, too, and they now have the 
numbers in terms of satellites, so it doesn't matter so much that these 
shells need a larger number of sats to work.

Now there are drawbacks also: The lower the orbits go, the more residual 
atmospheric drag there will be, and this expresses itself in either 
shorter sat lifespan or the need to carry more fuel, which either means 
they'll need to launch at a faster rate or with fewer sats per launch. 
It's also a bit more crowded in lower space, as this is where a lot of 
earth observation spacecraft sit (if you want to take detailed pics of 
the Earth's surface, you want it to be as close to your camera lens as 
you can have it), and some of those aren't there for open source public 
good science.

On 23/11/2024 11:33 am, Dave Taht via Starlink wrote:
> To me, the additional speeds don't matter all that much.
>
> I am presently in gale force winds, my boat rocking, and my latency
> stable, and only about 50mbit down:
> https://www.waveform.com/tools/bufferbloat?test-id=a14b4467-16d7-4b6e-8736-1593813d6eda
>
> Maybe a little less packet loss would help, as my last (hour long)
> videoconference broke up twice, and bbr is seriously outperforming
> cubic. In addition for aiming for higher speeds, improving density and
> reliability would be nice, but otherwise I am a pretty happy camper
> with the service I have, compared to 5g.
>
> On Fri, Nov 22, 2024 at 2:16 PM Hesham ElBakoury via Starlink
> <starlink@lists.bufferbloat.net> wrote:
>> https://cordcuttersnews.com/starlink-internet-speeds-could-skyrocket-to-2-gigabits-per-second-spacex-president-says/
>> _______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starlink
>
>
-- 
****************************************************************
Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)

The University of Auckland
u.speidel@auckland.ac.nz 
http://www.cs.auckland.ac.nz/~ulrich/
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