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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