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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Ulrich Speidel
[mailto:u.speidel@auckland.ac.nz] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Saturday, March 5, 2022 1:43
AM<br>
<b><span style='font-weight:bold'>To:</span></b> dickroy@alum.mit.edu; 'David
Lang'<br>
<b><span style='font-weight:bold'>Cc:</span></b> starlink@lists.bufferbloat.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Starlink] Starlink
Digest, Vol 12, Issue 6</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On 5/03/2022 7:38 pm, Dick Roy wrote:<o:p></o:p></span></font></p>
</div>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt' type=cite
cite="mid:2DA12D3D736443699EBFD93FDC9325A2@SRA6"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="State"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place">
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>-----Original
Message-----<br>
From: Starlink [<a href="mailto:starlink-bounces@lists.bufferbloat.net">mailto:starlink-bounces@lists.bufferbloat.net</a>]
On Behalf Of Ulrich Speidel<br>
Sent: Friday, March 4, 2022 4:14 PM<br>
To: David Lang<br>
Cc: <a href="mailto:starlink@lists.bufferbloat.net">starlink@lists.bufferbloat.net</a><br>
Subject: Re: [Starlink] Starlink Digest, Vol 12, Issue 6</span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>True,
but Starlink is designed as a high bandwidth, low latency (OK, we <u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>won't
mention their bufferbloat issues again here), and (currently) low <u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>user
density service.<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>Bandwidth-wise,
good old Shannon and Hartley are agnostic about whether <u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier
Ne"><span
style='font-size:10.0pt;font-family:"Courier\000D\000A Ne"'>you
divide your channel between 1 or a million users. <u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoPlainText><b><i><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-weight:bold;font-style:italic'>[RR] But they are
assuming a “single” channel in the time domain. When you can
take advantage of other dimensions (eg. space) to create more channels, (aka
SDMA) the capacity goes up!</span></font></i></b><o:p></o:p></p>
</blockquote>
<p class=MsoNormal><b><i><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";font-weight:bold;font-style:
italic'></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype>Taken
as read - but it's beside the point. Shannon-Hartley allows you to do what was
proposed - turning a channel that supplies a small number of users with a lot
of capacity each into one that supplies a large number of users with a little
capacity each, and of course if you add diversity (space, polarisation, ...)
then this applies even more so. But the point is that each communication system
is designed around an expectation of how many users will access it, and that
you can't simply take an existing technology and somehow assume that it will
work with a larger number of users just because it's theoretically possible.
Basically, you can't simply throw more dishys at the problem if you need to
serve more users.</span></font></i></b><br>
<br>
<font color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><b><i><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:navy;font-weight:bold;
font-style:italic'>[RR] Actually, to a certain extent it depends on how the “dishys
are/could be connected” and how the satellites overhead are “configured”,
but that’s a story for another day and related to the point about the Maverick
show ))). That said, I agree that systems have to be and are designed/optimized
to handle a specified load (really a range of loads) and can not be expected to
perform as well outside that range, and I agree that anyone who thinks that Shannon
can be simply be ignored (as was tried in the past by a very famous corporation
we all know all too well) is simply delusional. As the saying goes, “you can
not make chicken salad out of chicken feathers!”<o:p></o:p></span></font></i></b></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br>
<o:p></o:p></span></font></p>
<pre><font size=2 face="Courier New"><span style='font-size:10.0pt'>-- <o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>****************************************************************<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Dr. Ulrich Speidel<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><st1:place
w:st="on"><st1:PlaceType w:st="on"><font size=2 face="Courier New"><span
style='font-size:10.0pt'>School</span></font></st1:PlaceType> of <st1:PlaceName
w:st="on">Computer</st1:PlaceName></st1:place> Science<o:p></o:p></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Room 303S.594 (City Campus)<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>The <st1:place w:st="on"><st1:PlaceType
w:st="on">University</st1:PlaceType> of <st1:PlaceName w:st="on">Auckland</st1:PlaceName></st1:place><o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><a
href="mailto:u.speidel@auckland.ac.nz">u.speidel@auckland.ac.nz</a> <o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><a
href="http://www.cs.auckland.ac.nz/~ulrich/">http://www.cs.auckland.ac.nz/~ulrich/</a><o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>****************************************************************<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre></div>
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