Re: [Starlink] Starlink Roaming

[Mike Puchol <mike@starlink.sx>]

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Thank you for noticing the totally unintended pun! :-)

Best,

Mike
On Feb 22, 2022, 13:37 +0300, Vint Cerf <vint@google.com>, wrote:
> pun intended?
> Mynaric is one of the more visible ones.
>
> :-)
>
> v
>
>
>
> > On Tue, Feb 22, 2022 at 5:01 AM Mike Puchol <mike@starlink.sx> wrote:
> > > It all depends on the power. We operate FSOC terminals that can do 20 Gbps at 20km+, and are eye-safe (un-aided, if you look at one using binoculars, different story).
> > >
> > > Power also depends on receiver sensitivity, if you can reconstruct a signal from less photons, your power requirements drop, and efficiency increases. There is a lot of research going on in this field, and there are many companies that are trying to get into the ground-to-air optical link game. Mynaric is one of the more visible ones.
> > >
> > > Best,
> > >
> > > Mike
> > > On Feb 22, 2022, 12:46 +0300, Sebastian Moeller <moeller0@gmx.de>, wrote:
> > > >
> > > >
> > > > > On Feb 22, 2022, at 10:40, Mike Puchol <mike@starlink.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? In a lab context IR lasers are typically considered more dangerous as they are invisible 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-safety seminar ;)
> > > >
> > > >
> > > > > On David’s comment "but if you can easily route traffic to a ground station that's further away and not currently saturated”, that is true as long as the path that is connected over ISL has visibility of that other ground station. I will add ISL to my tracker shortly so we can start simulating these things.
> > > > >
> > > > > Best,
> > > > >
> > > > > Mike
> > > > > On Feb 22, 2022, 12:04 +0300, Sebastian Moeller <moeller0@gmx.de>, wrote:
> > > > > > Intersting!
> > > > > >
> > > > > > Silly question, giving that there are already law suits for people pointing lasers at airplanes, how are these commercial laster terminals avoiding that issue?
> > > > > >
> > > > > > Regards
> > > > > > Sebastian
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > > On Feb 22, 2022, at 08:42, Mike Puchol <mike@starlink.sx> wrote:
> > > > > > >
> > > > > > > I did over-simplify so the point was better understood. On the optical 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’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.
> > > > > > >
> > > > > > > Best,
> > > > > > >
> > > > > > > Mike
> > > > > > > On Feb 22, 2022, 10:20 +0300, Dick Roy <dickroy@alum.mit.edu>, wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > From: Starlink [mailto:starlink-bounces@lists.bufferbloat.net] On Behalf Of Mike Puchol
> > > > > > > > Sent: Monday, February 21, 2022 9:35 PM
> > > > > > > > To: Daniel AJ Sokolov; David Lang
> > > > > > > > Cc: starlink@lists.bufferbloat.net
> > > > > > > > Subject: Re: [Starlink] 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 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.).
> > > > > > > >
> > > > > > > > [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 thereJ)
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > Eventually they will go for optical gateways, it’s the only way to get enough capacity to the constellation, specially the 30k satellite version.
> > > > > > > >
> > > > > > > > [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.
> > > > > > > >
> > > > > > > >
> > > > > > > > Best,
> > > > > > > >
> > > > > > > > Mike
> > > > > > > >
> > > > > > > > On Feb 22, 2022, 05:17 +0300, David Lang <david@lang.hm>, wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > On Mon, 21 Feb 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
> > > > > > > > the future (my guess is that the laser satellites will enable a lot more
> > > > > > > > flexibility)
> > > > > > > >
> > > > > > > >
> > > > > > > > Isn't that a very optimistic assessment? :-)
> > > > > > > >
> > > > > > > > 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?
> > > > > > > >
> > > > > > > > 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?
> > > > > > > >
> > > > > > > >
> > > > > > > > My thinking is that the laser links will make it possible to route the traffic
> > > > > > > > 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, FAR more mobile that I will ever be :-) )
> > > > > > > >
> > > > > > > > David Lang
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>
> --
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> Vint Cerf
> 1435 Woodhurst Blvd
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>
> until further notice
>
>
>

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