From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vsmx002.dclux.xion.oxcs.net (vsmx002.dclux.xion.oxcs.net [185.74.65.108]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 3D95E3B29E for ; Tue, 22 Feb 2022 05:01:56 -0500 (EST) Received: from proxy-2.proxy.oxio.ns.xion.oxcs.net (proxy-2.proxy.oxio.ns.xion.oxcs.net [197.248.130.130]) by mx-out.dclux.xion.oxcs.net (Postfix) with ESMTPA id 993718C0308; Tue, 22 Feb 2022 10:01:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=dclux.xion.oxcs.net; s=mail1; t=1645524115; bh=lLYyboq08Z4szN7gnq43m6UETpZBc8DBkbFpZ7vWzkg=; h=Date:From:To:Cc:In-Reply-To:References:Subject:From; b=Fo1wE87I6jy/wwg/1d/zRPr9fdZP8U4v49jKI2dQSGsENfnYp5M6n34KszZI/tMI0 KDXXauaumfUL4JATqYu/D6enaG4e38STmHB/YTM0fKIMiRhuqfIUnAxQ95RRmfEchb ufcgvCWOfA5mcCD7aZXp9EPmslOSZwaLbhO/yvLfjK9iMDnkyyaTaV7NxaLnUt/PBY 86Yf2nw4H9YwOShskdVJdx8F4J3lxxufNnCNl/yLJFA6wE9c1VSfZx1YGvEIuEYbX7 Iy5hcM15vR5+KPNNTUI5j2cXsr3p/4MxgLZ7jmS3i1g8Z69IoRc58PX1QOv2jqeCki L+dEZvfXk2A0A== Date: Tue, 22 Feb 2022 13:01:39 +0300 From: Mike Puchol To: Sebastian Moeller Cc: Daniel AJ Sokolov , David Lang , dickroy@alum.mit.edu, starlink@lists.bufferbloat.net Message-ID: In-Reply-To: <282F58AF-C9A9-4438-AB82-34C717384DBE@gmx.de> References: <1p492142-q944-r494-6s6r-p6q37s57qnq4@ynat.uz> <1F1EB112F8CB446FAB4BF308A76955FA@SRA6> <0ac195f5-3668-4c96-8dec-8a2d59a0bd52@Spark> <866405-s043-n12n-6pqs-46o38r189218@ynat.uz> <38pr9p5s-3ro4-49p9-9535-7o92oqrq62r1@ynat.uz> <80753e77-f7ba-466f-8222-66c16059f600@Spark> <66B75B7A-82DF-4A92-BC74-CB0422E2BABC@gmx.de> <0ecefa3c-da5c-48c6-b60d-e2e121d1319c@Spark> <282F58AF-C9A9-4438-AB82-34C717384DBE@gmx.de> X-Readdle-Message-ID: bfe1b5f8-4ab2-40fd-b9b6-b0cd8560c4c6@Spark MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="6214b489_580bd78f_2ed6" X-VadeSecure-Status: LEGIT X-VADE-STATUS: LEGIT Subject: Re: [Starlink] Starlink Roaming X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2022 10:01:56 -0000 --6214b489_580bd78f_2ed6 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline It all depends on the power. We operate =46SOC terminals that can do 20 G= bps at 20km+, and are eye-safe (un-aided, if you look at one using binocu= lars, different story). Power also depends on receiver sensitivity, if you can reconstruct a sign= al from less photons, your power requirements drop, and efficiency increa= ses. There is a lot of research going on in this field, and there are man= y companies that are trying to get into the ground-to-air optical link ga= me. Mynaric is one of the more visible ones. Best, Mike On =46eb 22, 2022, 12:46 +0300, Sebastian Moeller , wr= ote: > > > > On =46eb 22, 2022, at 10:40, Mike Puchol wrote: > > > > The optical links work in IR spectrum, so non-visible. They would not= be a concern for aircraft the same way green lasers are. > > Puzzled. IR lasers still wreck havoc when hitting the eye/retina, so wh= y are these considered safer than visible spectrum lasers=3F In a lab con= text IR lasers are typically considered more dangerous as they are invisi= ble and hence harder to see/avoid. I am happy to believe that there is a = reason why they are safer, just trying ot reconcile that with my laser-sa= fety seminar ;) > > > > On David=E2=80=99s comment =22but if you can easily route traffic to = a ground station that's further away and not currently saturated=E2=80=9D= , that is true as long as the path that is connected over ISL has visibil= ity of that other ground station. I will add ISL to my tracker shortly so= we can start simulating these things. > > > > Best, > > > > Mike > > On =46eb 22, 2022, 12:04 +0300, Sebastian Moeller = , wrote: > > > Intersting=21 > > > > > > Silly question, giving that there are already law suits for people = pointing lasers at airplanes, how are these commercial laster terminals a= voiding that issue=3F > > > > > > Regards > > > Sebastian > > > > > > > > > > > > > > > > On =46eb 22, 2022, at 08:42, Mike Puchol wro= te: > > > > > > > > I did over-simplify so the point was better understood. On the op= tical gateways, these exist already: https://mynaric.com/products/ground-= capabilities/ > > > > > > > > Once you have an optical mesh in orbit, the only practical way to= provide it with massive capacity is optical links - there isn=E2=80=99t = enough radio spectrum that would do it (without a massive ground gateway = network with enough physical separation). You can create a network of opt= ical gateways that guarantees a number of them will not be impared by clo= ud cover at any given time. Optical has the advantage of being license-fr= ee, too. > > > > > > > > Best, > > > > > > > > Mike > > > > On =46eb 22, 2022, 10:20 +0300, Dick Roy = , wrote: > > > > > > > > > > > > > > > =46rom: Starlink =5Bmailto:starlink-bounces=40lists.bufferbloat= .net=5D On Behalf Of Mike Puchol > > > > > Sent: Monday, =46ebruary 21, 2022 9:35 PM > > > > > To: Daniel AJ Sokolov; David Lang > > > > > Cc: starlink=40lists.bufferbloat.net > > > > > Subject: Re: =5BStarlink=5D Starlink Roaming > > > > > > > > > > > > > > > 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. > > > > > > > > > > A satellite under full load can saturate two gateway links by i= tself. If you load, say, 20 satellites in an orbital plane, onto a single= gateway, over ISL, you effectively have 5% of each satellite=E2=80=99s c= apacity available (given an equal distribution of demand, of course there= will be satellites with no UTs to cover etc.). > > > > > > > > > > =5BRR=5D I think to do this analysis correctly; one needs to co= nsider the larger system and the time-varying loads on the components the= reof. What you say is true; just a bit over-simplified to be maximally us= eful. Routing through complex congested networks is well-studied problem = and hnts at possible solutions can probably be found thereJ) > > > > > > > > > > > > > > > > > > > > Eventually they will go for optical gateways, it=E2=80=99s the = only way to get enough capacity to the constellation, specially the 30k s= atellite version. > > > > > > > > > > =5BRR=5D What do you mean by =E2=80=9C=E2=80=9Doptical gateway=E2= =80=9D=3F An optical link from the satellite to the ground station=3F Tha= t would be real expensive at least power-wise and unreliable. > > > > > > > > > > > > > > > Best, > > > > > > > > > > Mike > > > > > > > > > > On =46eb 22, 2022, 05:17 +0300, David Lang , w= rote: > > > > > > > > > > > > > > > On Mon, 21 =46eb 2022, Daniel AJ Sokolov wrote: > > > > > > > > > > > > > > > On 2022-02-21 at 13:52, David Lang wrote: > > > > > > > > > > > > > > > > > > > > They told me that I could try it, and it may work, may be degra= ded a > > > > > bit, or may not work at all. They do plan to add roaming capabi= lities in > > > > > the future (my guess is that the laser satellites will enable a= lot more > > > > > flexibility) > > > > > > > > > > > > > > > Isn't that a very optimistic assessment=3F :-) > > > > > > > > > > Laser links are great for remote locations with very few users,= but how > > > > > could they relieve overbooking of Starlink in areas with too ma= ny users=3F > > > > > > > > > > The laser links can reduce the required density of ground stati= ons, but > > > > > they don't add capacity to the network. Any ground station not = built > > > > > thanks to laser links adds load to other ground stations - and,= maybe > > > > > more importantly, adds load to the satellite that does eventual= ly > > > > > connect to a ground station. > > > > > > > > > > Can laser links really help on a large scale, or are they just = a small > > > > > help here and there=3F > > > > > > > > > > > > > > > My thinking is that the laser links will make it possible to ro= ute the traffic > > > > > from wherever I am to the appropriate ground station that I'm r= egistered with as > > > > > opposed to the current bent-pipe approach where, if I move to f= ar from my > > > > > registered location, I need to talk to a different ground stati= on. > > > > > > > > > > Currently there are two limits in any area for coverage: > > > > > > > > > > 1. satellite bandwidth > > > > > 2. ground station bandwidth > > > > > > > > > > laser links will significantly reduce the effect of the second = one. > > > > > > > > > > We know that they can do mobile dishes (they are testing it cur= rently on Elon's > > > > > gulfstream, =46AR more mobile that I will ever be :-) ) > > > > > > > > > > David Lang > > > > > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F > > > > > Starlink mailing list > > > > > Starlink=40lists.bufferbloat.net > > > > > https://lists.bufferbloat.net/listinfo/starlink > > > > > > > > > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= > > > > Starlink mailing list > > > > Starlink=40lists.bufferbloat.net > > > > https://lists.bufferbloat.net/listinfo/starlink > > > > --6214b489_580bd78f_2ed6 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
It all depends on the power. We operate =46SOC term= inals that can do 20 Gbps at 20km+, and are eye-safe (un-aided, if you lo= ok at one using binoculars, different story).

Power also depends on receiver sensitivity, if you can reconstruct a sign= al from less photons, your power requirements drop, and efficiency increa= ses. There is a lot of research going on in this field, and there are man= y companies that are trying to get into the ground-to-air optical link ga= me. Mynaric is one of the more visible ones.

Best,

Mike
On =46eb 22, 2022, 12:46 +0300, Seb= astian Moeller <moeller0=40gmx.de>, wrote:


On =46eb 22, 2022, at 10:40, Mike Puchol &l= t;mike=40starlink.sx> wrote:

The optical links work in IR spectrum, so non-visible. They would not be = a concern for aircraft the same way green lasers are.

Puzzled. IR lasers still wreck havoc when hitting the eye/retina, so why = are these considered safer than visible spectrum lasers=3F In a lab conte= xt IR lasers are typically considered more dangerous as they are invisibl= e and hence harder to see/avoid. I am happy to believe that there is a re= ason why they are safer, just trying ot reconcile that with my laser-safe= ty seminar ;)


On David=E2=80=99s comment =22but if you ca= n easily route traffic to a ground station that's further away and not cu= rrently saturated=E2=80=9D, that is true as long as the path that is conn= ected over ISL has visibility of that other ground station. I will add IS= L to my tracker shortly so we can start simulating these things.

Best,

Mike
On =46eb 22, 2022, 12:04 +0300, Sebastian Moeller <moeller0=40gmx.de&g= t;, wrote:
Intersting=21

Silly question, giving that there are already law suits for people pointi= ng lasers at airplanes, how are these commercial laster terminals avoidin= g that issue=3F

Regards
Sebastian




On =46eb 22, 2022, at 08:42, Mike Puchol &l= t;mike=40starlink.sx> wrote:

I did over-simplify so the point was better understood. On the optical ga= teways, these exist already: https://mynaric.com/products/ground-capabili= ties/

Once you have an optical mesh in orbit, the only practical way to provide= it with massive capacity is optical links - there isn=E2=80=99t enough r= adio spectrum that would do it (without a massive ground gateway network = with enough physical separation). You can create a network of optical gat= eways 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.=

Best,

Mike
On =46eb 22, 2022, 10:20 +0300, Dick Roy <dickroy=40alum.mit.edu>, = wrote:


=46rom: Starlink =5Bmailto:starlink-bounces=40lists.bufferbloat.net=5D On= Behalf Of Mike Puchol
Sent: Monday, =46ebruary 21, 2022 9:35 PM
To: Daniel AJ Sokolov; David Lang
Cc: starlink=40lists.bufferbloat.net
Subject: Re: =5BStarlink=5D Starlink Roaming


Actually, laser links would make gateway connectivity *worse*. If we take= the scenario attached, one gateway is suddenly having to serve traffic f= rom all UTs that were not previously under coverage.

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=E2=80=99s capacity av= ailable (given an equal distribution of demand, of course there will be s= atellites with no UTs to cover etc.).

=5BRR=5D 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. Rout= ing through complex congested networks is well-studied problem and hnts a= t possible solutions can probably be found thereJ)



Eventually they will go for optical gateways, it=E2=80=99s the only way t= o get enough capacity to the constellation, specially the 30k satellite v= ersion.

=5BRR=5D What do you mean by =E2=80=9C=E2=80=9Doptical gateway=E2=80=9D=3F= An optical link from the satellite to the ground station=3F That would b= e real expensive at least power-wise and unreliable.


Best,

Mike

On =46eb 22, 2022, 05:17 +0300, David Lang <david=40lang.hm>, wrote= :


On Mon, 21 =46eb 2022, Daniel AJ Sokolov wrote:


On 2022-02-21 at 13:52, David Lang wrote:



They told me that I could try it, and it may work, may be degraded a
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)


Isn't that a very optimistic assessment=3F :-)

Laser links are great for remote locations with very few users, but how could they relieve overbooking of Starlink in areas with too many users=3F=

The laser links can reduce the required density of ground stations, but they don't add capacity to the network. Any ground station not built
thanks to laser links adds load to other ground stations - and, maybe
more importantly, adds load to the satellite that does eventually
connect to a ground station.

Can laser links really help on a large scale, or are they just a small help here and there=3F


My thinking is that the laser links will make it possible to route the tr= affic
from wherever I am to the appropriate ground station that I'm registered = with as
opposed to the current bent-pipe approach where, if I move to far from my=
registered location, I need to talk to a different ground station.

Currently there are two limits in any area for coverage:

1. satellite bandwidth
2. ground station bandwidth

laser links will significantly reduce the effect of the second one.
=
We know that they can do mobile dishes (they are testing it currently on = Elon's
gulfstream, =46AR more mobile that I will ever be :-) )

David Lang
=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F
Starlink mailing list
Starlink=40lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/starlink

=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F
Starlink mailing list
Starlink=40lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/starlink


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