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<p>It's 20 km in diameter, roughly.</p>
<p></p>
<div class="moz-cite-prefix">On 2/24/23 02:51, Ulrich Speidel via
Starlink wrote:<br>
</div>
<blockquote type="cite"
cite="mid:8828a1a5-0be7-da93-c08f-1e6b83b046a4@auckland.ac.nz">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Did you mean to say 20 km diameter or 20 km^2 area?<br>
</p>
<p>For those not familiar with RF engineering terms: A 3 dB
contour as Oleg shows it below in blue is the line where the
power flux density from the satellite drops to half of the value
at the centre of the beam. That's important as in RF engineering
of cellular or beam division networks, the minimum power you
need to receive a signal successfully can be several orders of
magnitude larger than the amount of power you need to cause
interference to off-beam unintended receivers. So in terms of
their interference contour, beams are actually much wider than
just a cell or so, and a power flux density half as high as at
beam centre doesn't mean that it's the perimeter of the beam as
such - the beam will happily interfere with anyone up to a few
cells down the road at least. <br>
</p>
<p>Incidentally, I'm seeing Dishy use more power when it's
receiving at higher rates, which is what you'd expect if its DSP
is busy digging out intended signals from unintended ones.<br>
</p>
<div class="moz-cite-prefix">On 24/02/2023 1:18 pm, Oleg Kutkov
via Starlink wrote:<br>
</div>
<blockquote type="cite"
cite="mid:9dd258eb-1bdb-4234-1301-744ee77b4097@olegkutkov.me">
<p>Yes. The cell size is ~20 km</p>
<p><img src="cid:part1.cRlcc4S0.L05gXlpy@olegkutkov.me" alt=""
class="" width="320" height="240"></p>
<div class="moz-cite-prefix">On 2/24/23 02:08, David Lang wrote:<br>
</div>
<blockquote type="cite"
cite="mid:q61966n4-ns93-25qn-899o-3r8os67q7qos@ynat.uz">they
can only narrow the radio beam so much (probably whatever
their cell size is). They can't change the footprint without
changing the antenna, so unless they have the beam move around
in the cell, the footprint should be slightly larger than the
cell size <br>
<br>
sometimes there is a lot of data going to one station, but
sometims it's only going to be a trival amount (think ack
packets for a lot of uploads), so they can save airtime by
using one timeslot to transmit to many stations at once. <br>
<br>
David Lang <br>
<br>
On Fri, 24 Feb 2023, Oleg Kutkov via Starlink wrote: <br>
<br>
<blockquote type="cite">Date: Fri, 24 Feb 2023 01:47:05 +0200
<br>
From: Oleg Kutkov via Starlink <a
class="moz-txt-link-rfc2396E"
href="mailto:starlink@lists.bufferbloat.net"
moz-do-not-send="true"><starlink@lists.bufferbloat.net></a>
<br>
Reply-To: Oleg Kutkov <a class="moz-txt-link-rfc2396E"
href="mailto:contact@olegkutkov.me" moz-do-not-send="true"><contact@olegkutkov.me></a>
<br>
To: <a class="moz-txt-link-abbreviated
moz-txt-link-freetext"
href="mailto:starlink@lists.bufferbloat.net"
moz-do-not-send="true">starlink@lists.bufferbloat.net</a>
<br>
Subject: Re: [Starlink] System and method of providing a
medium access control <br>
scheduler <br>
<br>
Oh, that's interesting. <br>
<br>
>> the satellite broadcasts the downlink radio frame
to all the user terminals in a group and they each retrieve
their respective data from the downlink radio frame <br>
<br>
I thought the satellite beamformer only sends data frames to
the appropriate UT. It looks like the given satellite covers
the whole cell at one TX channel. <br>
Otherwise, it would be too complex, I guess. <br>
<br>
On 2/23/23 23:53, Dave Taht via Starlink wrote: <br>
<blockquote type="cite">For those of you that don't look at
patents, don't look at: <br>
<br>
<a class="moz-txt-link-freetext"
href="https://patents.justia.com/patent/11540301"
moz-do-not-send="true">https://patents.justia.com/patent/11540301</a>
<br>
<br>
But I would welcome comment from those that do. <br>
<br>
H/T virtuallynathan. <br>
<br>
</blockquote>
<br>
</blockquote>
</blockquote>
<pre class="moz-signature" cols="72">--
Best regards,
Oleg Kutkov</pre>
<br>
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</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 moz-txt-link-freetext" href="mailto:u.speidel@auckland.ac.nz" moz-do-not-send="true">u.speidel@auckland.ac.nz</a>
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<pre class="moz-signature" cols="72">--
Best regards,
Oleg Kutkov</pre>
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