<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:"MS Mincho";
panose-1:2 2 6 9 4 2 5 8 3 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"\@MS Mincho";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:blue;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=EN-US link=blue vlink=blue>
<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>All excellent points and right on! Thanks!<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>RR<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=3 width="100%" align=center tabindex=-1>
</span></font></div>
<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'> Mike Puchol
[mailto:mike@starlink.sx] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, February 21, 2022
11:42 PM<br>
<b><span style='font-weight:bold'>To:</span></b> 'Daniel AJ Sokolov'; 'David
Lang'; dickroy@alum.mit.edu<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
Roaming</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>
<div name=messageBodySection>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I did over-simplify so the point was better understood. On the optical
gateways, these exist already: <a
href="https://mynaric.com/products/ground-capabilities/" target="_blank">https://mynaric.com/products/ground-capabilities/</a><br>
<br>
Once you have an optical mesh in orbit, the only practical way to provide it
with massive capacity is optical links - there isn’t enough radio spectrum that
would do it (without a massive ground gateway network with enough physical
separation). You can create a network of optical gateways that guarantees a
number of them will not be impared by cloud cover at any given time. Optical
has the advantage of being license-free, too.<o:p></o:p></span></font></p>
</div>
</div>
<div name=messageSignatureSection>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Best,<br>
<br>
Mike<o:p></o:p></span></font></p>
</div>
</div>
<div name=messageReplySection>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Feb 22, 2022, 10:20 +0300, Dick Roy <dickroy@alum.mit.edu>,
wrote:<br>
<br>
<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'> </span></font><o:p></o:p></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=3 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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'>Starlink [mailto:starlink-bounces@lists.bufferbloat.net]
<b><span style='font-weight:bold'>On Behalf Of</span></b> Mike Puchol<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, February 21, 2022
9:35 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Daniel AJ Sokolov; 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
Roaming</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<div name=messageBodySection>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>Actually, laser
links would make gateway connectivity *worse*. If we take the scenario
attached, one gateway is suddenly having to serve traffic from all UTs that
were not previously under coverage. <br>
<br>
A satellite under full load can saturate two gateway links by itself. If you
load, say, 20 satellites in an orbital plane, onto a single gateway, over ISL,
you effectively have 5% of each satellite’s capacity available (given an equal
distribution of demand, of course there will be satellites with no UTs to cover
etc.).<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><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] I think to do this analysis
correctly; one needs to consider the larger system and the time-varying loads
on the components thereof. What you say is true; just a bit over-simplified to
be maximally useful. Routing through complex congested networks is well-studied
problem and hnts at possible solutions can probably be found there</span></font></i></b><b><i><font
size=2 color=navy face=Wingdings><span style='font-size:10.0pt;font-family:
Wingdings;color:navy;font-weight:bold;font-style:italic'>J</span></font></i></b><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'>)</span></font></i></b><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
<br>
Eventually they will go for optical gateways, it’s the only way to get enough
capacity to the constellation, specially the 30k satellite version.<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><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] What do you mean by
“”optical gateway”? An optical link from the satellite to the ground station?
That would be real expensive at least power-wise and unreliable.</span></font></i></b><o:p></o:p></p>
</div>
</div>
<div name=messageSignatureSection>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
Best,<br>
<br>
Mike<o:p></o:p></span></font></p>
</div>
<div name=messageReplySection>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>On Feb 22, 2022,
05:17 +0300, David Lang <david@lang.hm>, wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>On Mon, 21 Feb
2022, Daniel AJ Sokolov wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>On 2022-02-21 at
13:52, David Lang wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
They told me that I could try it, and it may work, may be degraded a<br>
bit, or may not work at all. They do plan to add roaming capabilities in<br>
the future (my guess is that the laser satellites will enable a lot more<br>
flexibility)<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
Isn't that a very optimistic assessment? :-)<br>
<br>
Laser links are great for remote locations with very few users, but how<br>
could they relieve overbooking of Starlink in areas with too many users?<br>
<br>
The laser links can reduce the required density of ground stations, but<br>
they don't add capacity to the network. Any ground station not built<br>
thanks to laser links adds load to other ground stations - and, maybe<br>
more importantly, adds load to the satellite that does eventually<br>
connect to a ground station.<br>
<br>
Can laser links really help on a large scale, or are they just a small<br>
help here and there?<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
My thinking is that the laser links will make it possible to route the traffic<br>
from wherever I am to the appropriate ground station that I'm registered with
as<br>
opposed to the current bent-pipe approach where, if I move to far from my<br>
registered location, I need to talk to a different ground station.<br>
<br>
Currently there are two limits in any area for coverage:<br>
<br>
1. satellite bandwidth<br>
2. ground station bandwidth<br>
<br>
laser links will significantly reduce the effect of the second one.<br>
<br>
We know that they can do mobile dishes (they are testing it currently on Elon's<br>
gulfstream, FAR more mobile that I will ever be :-) )<br>
<br>
David Lang<br>
_______________________________________________<br>
Starlink mailing list<br>
Starlink@lists.bufferbloat.net<br>
https://lists.bufferbloat.net/listinfo/starlink<o:p></o:p></span></font></p>
</div>
</div>
</div>
</div>
</body>
</html>