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<p>Thanks for that! Another few interesting pieces to the jigsaw
puzzle.</p>
<p>I've been a bit reluctant to enter the performance measurement
game around Starlink myself, chiefly because it's a moving target
in more than one sense, so essentially you end up producing
(nevertheless useful) snapshots. There's the rapid growth in
satellite numbers and hence the associated change in Dishy
behaviour and improved performance in conditions where Dishy has
obstructions to deal with. There's the advent of the ISLs. There's
also the fact that we don't know which underlying changes are made
by SpaceX in terms of network configuration.</p>
<p>5G is also a moving target in its own right.</p>
<p>Handovers: I think it's important to consider that while your
Dishy might not get handed over, others operating via the same
satellite might move away and yet others again might join the
satellite you're on. So it's not just the potential of you moving
away to a satellite that looks different in terms of load, it's
also a matter of your satellite's capacity changing during someone
else getting handed over to it with cwnd wide open and being
allocated fewer slots than before. But, again, as mentioned above,
good on SpaceX if they're using some form of AQM to try and manage
this.</p>
<p>My most serious concern about Starlink as a system remains the
fact that it puts a pipe between the end user and the first
network hop (the satellite) that is in principle very difficult to
scale: There's only so much extra spectrum one can use, spatial
diversity (beamforming) has limited potential, and unlike in
cellular networks, you can't really shrink the cell size to
accommodate more end users through frequency re-use as your cell
size is determined to a good part by orbital altitude. That all
but rules out the scaling effects that CDNs have brought to the
rest of the Internet, which keep orders of magnitude worth of
traffic off long distance cables. There simply isn't an obvious
place in LEO topology to put a cache that'll produce a decent
number of hits while being able to serve this content to end users
through a large collective bandwidth.</p>
<p>The interesting question for me is how much we can scale Starlink
and its up-and-coming cousins from the few million users Starlink
has now. To 100 million? To 200 million? Half a billion even?</p>
<div class="moz-cite-prefix">On 27/02/2024 7:12 am, Nitinder Mohan
via Starlink wrote:<br>
</div>
<blockquote type="cite" cite="mid:etPan.65dcd4b4.593a6eed.2c4@in.tum.de">
<style>body{font-family:CMU Sans Serif,Arial;font-size:14px}</style>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">Hi
folks,</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; "><br>
</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">Our
comprehensive multifaceted measurement study looking at Starlink
global and last-mile performance is now available online: <a href="https://arxiv.org/abs/2310.09242" moz-do-not-send="true">https://arxiv.org/abs/2310.09242</a>. </div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; "><br>
</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">TL;DR:
See the summary in this nice teaser video we made: <a href="https://youtu.be/WtE3MoK8J80" moz-do-not-send="true">https://youtu.be/WtE3MoK8J80</a> </div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; "><br>
</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">We
looked at several third-party measurement sources (M-Lab, RIPE
Atlas) and performed our own measurements over multiple Starlink
dishes to uncover the following:</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; "><br>
</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">1.
How different is Starlink network performance globally? How do
ground station and PoP availability impact performance?</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">2.
How much latency is consumed by the satellite part of the link?</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">3.
Is Starlink connection affected by bufferbloat?</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">4.
Are satellite handovers the root-cause of Starlink 15-sec
reconfigurations?</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">5.
How good is Starlink compared to terrestrial cellular networks
for real-time applications, specifically Cloud Gaming and Zoom.</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; "><br>
</div>
<div style="font-family:CMU Sans Serif,Arial;font-size:14px; ">The
study has been accepted and will appear in <a href="https://www2024.thewebconf.org" moz-do-not-send="true">ACM The Web Conference 2024</a> (WWW),
which is a flagship venue that has historically housed several
pioneering works central to Internet success.</div>
<div><br>
</div>
<div>Feel free to let me know if you have any questions related to
the work. </div>
<div><br>
</div>
P.S. We also thanked this mailing list in our paper for providing
us several key insights and inquisitive discussions :)
<div><br>
<div class="gmail_signature"><font face="CMUSansSerif"><span style="font-style: normal; font-size: 14px;">Thanks and
Regards</span></font>
<div><font face="CMUSansSerif"><span style="font-style: normal; font-size: 14px;"><br>
</span></font></div>
<div><font face="CMUSansSerif"><span style="font-style: normal; font-size: 14px;">Nitinder
Mohan</span></font></div>
<div><font face="CMUSansSerif"><span style="font-style: normal; font-size: 14px;">Technical
University Munich (TUM)</span></font></div>
<div><a href="https://www.nitindermohan.com/" style="font-style: normal; font-size: 14px;" moz-do-not-send="true"><font face="CMUSansSerif">https://www.nitindermohan.com/</font></a></div>
</div>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
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</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
****************************************************************
Dr. Ulrich Speidel
School of Computer Science
Room 303S.594 (City Campus)
The University of Auckland
<a class="moz-txt-link-abbreviated" href="mailto:u.speidel@auckland.ac.nz">u.speidel@auckland.ac.nz</a>
<a class="moz-txt-link-freetext" href="http://www.cs.auckland.ac.nz/~ulrich/">http://www.cs.auckland.ac.nz/~ulrich/</a>
****************************************************************
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