[Starlink] Re: Starlink Digest, Vol 53, Issue 10

[Starlink] Re: Starlink Digest, Vol 53, Issue 10

[David P. Reed]

Just a random thought -
Two facts about LEO satellites that should allow much better capacity scaling for the network:

1) all the antennas are moving relative to each other, and relative to additive "noise" sources. This motion has been shown, in theory, to boost total achievable wireless communications capacity of the multi-input, multi-output channel they share. Grossglauser and Tse at Berkeley showed a technique that demonstrated a capacity that grows linearly with N, rather then sqrt(N), as N - the number of communicating nodes increases:

[ https://ieeexplore.ieee.org/document/916631 ]( https://ieeexplore.ieee.org/document/916631 )
 
2) The antennas of all the nodes are dispersed in space, with every path being "independent" in terms of the others. This dispersed array allows one to treat the received signal at each node as separable from each other (especially if "channel coded" and "error detecting") by essentially a "matrix inversion" operator. Again, the benefit is that capacity of the system grows at least linearly with N. Techniques for this case include a variety of designs. There's a nice theoretical overview here:

https://dl.acm.org/doi/10.1109/TIT.2009.2034819

3) There is a fair amount of scattering in the LEO-ground paths. Scattering can significantly boost overall communications capacity if you design your system around that. Lots of work in this research area, such as a very old set of work from Bell Labs, V-BLAST.

[ https://ieeexplore.ieee.org/document/738086 ]( https://ieeexplore.ieee.org/document/738086 )
 
Now, there are special regulatities that can be exploited in the physical predictability of the channel itself - all the endpoints are following quite predictable paths no matter how crooked they are - the "inverse kinematics" of the system are quite simple, which is the secret of why GPS as a system can be quite accurate, too - everything involved is "ballistic" driven by Newtonian gravity.

That means, of course, that there's little variation that is "random" - thus no "noise" in the channel. (Noise is just measurment unpredictability due to external factors). And from an information theory modeling perspective, no-noise means infinite channel capacity. (S/N = infinity). However, it is worth knowing that to make use of spatial information effectively the "analog layer" of equipment matters - a phased array radar deals with phase differences by using analog time-delay, rather than quantized ADC sampling, to get the most information out of phased antenna arrays. Or analogously, older "deghosting" receivers use so-called "RAKE" receivers that have adjustable taps at analog time-delays relative to the antenna's input where the signal is quantized.

So perhaps the best summation is this: given a bunch of dispersed LEO satellites and ground transceivers, Starlink currently operates very poorly compared to what the best achievable signalling rates would be.
However, to scale better (linearly or super-linearly in the total capacity with respect to number of stations and satellites), a very different architecture of the radio systems needs to be done.
The technical risk of that re-architecture is huge. Way beyond the capability of the "Muskrats", I suspect.
So much of the theory has not been actually reduced to practical implementation here.

And many of these technologies are attacked by incumbent providers when they pop up as potential competitors, even in simple forms. That's why I and others got kicked off the FCC TAC, for example, by a consortium of incumbent wireless operators who got the George W. Bush White House to order the end of the Spectrum Policy Task Force.
 
On Thursday, September 25, 2025 02:00, starlink-request@lists.bufferbloat.net said:



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> 1. Re: Starlink looking less niche as its retail presence expands
> (Luis A. Cornejo)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Wed, 24 Sep 2025 18:39:13 -0500
> From: "Luis A. Cornejo" <luis.a.cornejo@gmail.com>
> Subject: [Starlink] Re: Starlink looking less niche as its retail
> presence expands
> To: Ulrich Speidel <u.speidel@auckland.ac.nz>
> Cc: starlink@lists.bufferbloat.net
> Message-ID:
> <CAKJdXWCS7jKb+kvOWR5LTBvXRtzom_bdw9iaCjHMcDdS63OtWw@mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Since Starlink controls all the wireless parts of their system. Does
> anybody here know what they could do to mitigate the limits of classical
> wireless comms, like Shannon-Hartley Capacity
> Theorem or the interference?
> 
> Wouldn’t approaches like P-Cell or Tarana’s where noise is cancelled
> or
> nulled from the same frequencies to allow a substantial reuse of channels
> in neighboring cells? I can only assume they are doing some of it, but not
> to what extent.
> 
> I wonder if Dr. Reed can weigh in specially with something like Orbital
> Angular Momentum advances or more cooperative Tx/Rx that he has mentioned
> before? “Smarter” transceivers if you will.
> 
> https://deepplum.com/some-thoughts-on-orbital-angular-momentum-oam-for-future-radio/
> 
> -Luis
> 
> On Wed, Sep 17, 2025 at 6:02 PM Ulrich Speidel via Starlink <
> starlink@lists.bufferbloat.net> wrote:
> 
> > Worth looking a bit beyond the marketing, the gushing influencers, and
> > the various bloggers.
> >
> > 99% of the folk who keep reporting on Starlink don't consider three
> > aspects that are absolutely key:
> >
> > 1. What areas new connectivity is being sold to.
> > 2. What the existing user density in these areas is.
> > 3. How much data rate you need when push comes to shove.
> >
> > The simple fact is that Starlink uses Ku band spectrum for end user
> > downlink. That spectrum is limited (as in "Hertz", or about 2 GHz, to be
> > more specific, and further constrained by licensing issues in quite a
> > few places). Support by existing hardwaree aside, going further down in
> > frequency isn't really an option as there are existing services there.
> > Going further up, and you'll increasingly find that weather makes life
> > really difficult with consumer-sized antennas.
> >
> > So to squeeze the combined bit rates of all of your users through this
> > spectrum, Starlink needs power. It needs that power in space, where the
> > only way to generate it is with solar cells that are in the dark for
> > half the orbit. Assuming for a moment that Starlink is able to produce
> > enough power on its fleet for enough beams to point at enough cells, it
> > also needs the ability to project that power to the receivers on the
> > ground. This is where EPFD limits come in - there's an international
> > agreed-upon legal limit on how much power satellites can project onto
> > the ground, and with it's Gen 2 sats, Starlink is already right up
> > against that limit.
> >
> > Let's recap: Spectrum's boxed in, and power is boxed in. That imposes a
> > hard limit on total capacity (look up the Shannon-Hartley Capacity
> > Theorem if you don't believe me). This capacity is all that Starlink has
> > to share among its users in a cell. No matter how many satellites they
> > launch or how big the rocket. Add more users in a cell, and the capacity
> > per user there has to go down. Law of nature.
> >
> > But it's a little more constrained even: Enter wider area needs, beams,
> > and enter competition. Even if a particular sub-band of the Ku band
> > spectrum isn't in use in a cell for downlink at a given moment, it
> > doesn't actually mean that it's available for use there. That's (a)
> > because the beams that are currently pointing at the cell already reach
> > the EPFD limit, (b) because a beam operating on that frequency might
> > already be in use in a cell nearby downlinking to users there, and leak
> > enough signal over into our target cell to ensure the sub-band can't be
> > used there because it would interfere, (c) because you mightn't have a
> > satellite with an available beam to service the cell (this is the ONLY
> > problem more sats can fix) and (d) because the likes of Kuiper & Co.
> > also need / want / are entitled to some of that Ku band spectrum. It's
> > not like you can launch a new LEO system and simply set up shop in a
> > completely different part of the spectrum.
> >
> > So what does this mean?
> >
> > From a commercial perspective, Starlink wants to make money, of course.
> > But that requires them to have something to sell.
> >
> > In truly rural areas with low user density, where Starlink has spare
> > capacity in the spectrum, this is a no-brainer - there is something to
> > sell, and new users fill gaps there without impacting on what's
> > available to existing ones. In rural towns with a few ten thousand
> > people per cell and poop fibre and mobile infrastructure, that capacity
> > isn't a given - so just selling full-rate plans with Dishys there is
> > moving the system towards capacity. In cities and suburbia, it's a mixed
> > picture depending on the local infrastructure. Where there's strong
> > competition from cheap fibre and people tend to live in apartments that
> > can't see the sky, Starlink's a hard sell, but even there a marketing
> > drive might net more users than the system can really support simply
> > because the market in each cell there is large.
> >
> > There is plenty of indication that Starlink has been grappling with
> > capacity for a while now. We saw them discover their heart for the
> > "rural" NZ farmer a couple of years ago, including a lot of townsfolk in
> > secondary cities here, whereas the lifestyle blocks around Auckland
> > (where all the IT managers live beyond the reach of fibre) were
> > mysteriously classified as "urban" and ineligible for the substantial
> > rural discount on new Dishys. We've seen "sold out" signs go up on the
> > availability map. We've seen minimum download rates drop in many areas.
> > We've seen one-off congestion surcharges and now discounted lower
> > capacity plans - smaller slices off the total capacity cake.
> >
> > This isn't trying to blame Starlink - it's a fantastic system - but like
> > the rest of us have to live within what the spectrum and physics
> > provide, and the better we as users understand where the limitations
> > are, the better the decisions we can make for our own connectivity. And
> > that might at times actually leave capacity for people who need it more
> > than we do.
> >
> > On 18/09/2025 7:04 am, Inemesit Affia via Starlink wrote:
> > > I expect if starship is successful and Amazon mounts a challenge, well
> > see
> > > the most expensive Starlink Residential plan be around the US (wired)
> > > average. I believe that's around $70
> > >
> > > On Wed, Sep 17, 2025, 7:46 PM Frantisek Borsik<
> > frantisek.borsik@gmail.com>
> > > wrote:
> > >
> > >> Starlink will become that 2nd or 3rd connectivity option for many,
> in
> > the
> > >> coming years - and Kuiper, presumably others, as well. Especially
> with
> > the
> > >> introduction of that standby $5 program. They might bring other
> tiers
> > for
> > >> something like that in the future.
> > >>
> > >> And for some, especially in the rural areas, it will be the one and
> only
> > >> option (not crazy expensive and hard to get.)
> > >>
> > >> All the best,
> > >>
> > >> Frank
> > >>
> > >> Frantisek (Frank) Borsik
> > >>
> > >>
> > >> *In loving memory of Dave Täht: *1965-2025
> > >>
> > >> https://libreqos.io/2025/04/01/in-loving-memory-of-dave/
> > >>
> > >>
> > >> https://www.linkedin.com/in/frantisekborsik
> > >>
> > >> Signal, Telegram, WhatsApp: +421919416714
> > >>
> > >> iMessage, mobile: +420775230885
> > >>
> > >> Skype: casioa5302ca
> > >>
> > >> frantisek.borsik@gmail.com
> > >>
> > >>
> > >> On Wed, Sep 17, 2025 at 8:21 PM Inemesit Affia via Starlink
> <
> > >> starlink@lists.bufferbloat.net> wrote:
> > >>
> > >>> Starlink is *advertised* as a rural product as opposed to
> relegated to
> > >>> one.
> > >>> It's available to be used everywhere just like tractors and cow
> milking
> > >>> machines.
> > >>>
> > >>> In Africa, most users are urban. I'm willing to bet there are
> more
> > >>> urban+suburban users in the USA and Australia.
> > >>>
> > >>> There are many pockets of unavailability and unreliability.
> > >>>
> > >>> I remember seeing a user in a new skyscraper. No mobile service
> there.
> > >>>
> > >>> The benefit for users having retail(including online)
> availability IMO
> > is
> > >>> getting hardware & replacements on short notice. Same day or
> next day.
> > >>>
> > >>> On Wed, Sep 17, 2025, 5:55 PM the keyboard of geoff goodfellow
> via
> > >>> Starlink
> > >>> <starlink@lists.bufferbloat.net> wrote:
> > >>>
> > >>>> *Starlink has nearly a dozen retail partners in the US,
> including Best
> > >>> Buy
> > >>>> and Walmart, illustrating the company's desire to make the
> satellite
> > >>>> service less of a niche, rural play. However, Starlink's
> subs still
> > >>> skew to
> > >>>> rural areas.*
> > >>>> EXCERPT:
> > >>>>
> > >>>> The Starlink satellite broadband service remains largely
> relegated to
> > >>> rural
> > >>>> areas and does not yet represent a major, direct competitor
> to
> > wireline
> > >>>> broadband service providers and fixed wireless access (FWA)
> offerings
> > in
> > >>>> urban areas.
> > >>>>
> > >>>>
> > >>>> But Starlink's expanding presence at retail sites –
> along with some
> > >>> recent
> > >>>> price cuts – indicates the company isn't content for
> the service to be
> > >>>> limited as a niche offering.
> > >>>>
> > >>>>
> > >>>> Jeff Moore, principal of Wave7 Research and a watcher of
> marketing
> > >>> trends
> > >>>> across the mobile, satellite and broadband landscapes,
> discovered back
> > >>> in
> > >>>> March that Starlink was being sold broadly at Best Buy
> stores.
> > >>>>
> > >>>>
> > >>>> "Since March, every single Best Buy that we have checked in
> every
> > state
> > >>> has
> > >>>> had a highly visible display for Starlink," Moore said,
> adding that
> > most
> > >>>> tend to be "endcap" displays placed at the end of aisles.
> > >>>>
> > >>>>
> > >>>> And Starlink has been broadening its retail footprint.
> Citing
> > >>>> Starlink's evolving
> > >>>> list of retail partners
> > >>>> <
> > >>>>
> > >>>
> >
> https://www.starlink.com/support/article/8a90222d-7c32-edd7-51f6-f696ece07105
> > >>>>> ,
> > >>>> Moore points out that the service is also being sold by a
> mix of
> > big-box
> > >>>> stores and smaller outlets, including Home Depot, Nebraska
> Furniture
> > >>> Mart,
> > >>>> West Marine, Bass Pro Shops, Cabela's, Microcom, Thor
> Industries,
> > >>> Tractor
> > >>>> Supply, Winegard Company and Walmart.
> > >>>>
> > >>>>
> > >>>> But Starlink's retail presence is not exactly uniform.
> According to
> > >>> Wave7's
> > >>>> in-person checks, Walmart, for example, has Starlink
> displays at some
> > >>>> stores but not in others.
> > >>>>
> > >>>> Moore also points out that Starlink's retail presence is not
> limited
> > to
> > >>>> rural areas. "We're not seeing it slice that way at all," he
> said.
> > >>>>
> > >>>> Moore said Home Depot is getting more aggressive with
> Starlink, even
> > if
> > >>> its
> > >>>> displays are not exactly "glittering jewels of
> commercialism."
> > >>>>
> > >>>> "They're sort of non-descript displays. If you know what
> you're
> > looking
> > >>>> for, you can find it," he said.
> > >>>>
> > >>>> That said, Starlink is a "priority" for Home Depot this year
> and
> > "sales
> > >>>> have been strong," Moore said, citing information from what
> he says
> > is a
> > >>>> well-placed source familiar with the chain. However, the
> lion's share
> > of
> > >>>> those sales have been online rather than in-store, he
> added.
> > >>>>
> > >>>> So, what to make of Starlink's increased focus on retail?
> Moore thinks
> > >>> it's
> > >>>> a way for Starlink to gravitate away from being a "niche"
> product into
> > >>> more
> > >>>> of a mass-market product.
> > >>>>
> > >>>> Retail partnerships give Starlink another sales channel
> without having
> > >>> to
> > >>>> shell out millions to erect its own physical storefronts.
> However, the
> > >>>> retail experience, particularly at big-box stores, can be
> lackluster.
> > >>>>
> > >>>> Roger Entner, founder and analyst at Recon Analytics, said
> his data
> > >>> shows
> > >>>> that satisfaction with the sales process at big-box
> retailers is
> > >>> "abysmal,"
> > >>>> driving negative net promoter scores (NPS). Meanwhile, most
> Starlink
> > >>> sales
> > >>>> occur online.
> > >>>>
> > >>>>
> > >>>> *Who are Starlink's customers?*
> > >>>> Starlink, which relies on a constellation of low-Earth orbit
> (LEO)
> > >>>> satellites, reported in July that it has more than 2 million
> active
> > >>>> customers in the US. By comparison, its geosynchronous (GEO)
> satellite
> > >>>> broadband competitors – Hughes Network Systems and
> Viasat – are much
> > >>>> smaller and losing subscribers.
> > >>>>
> > >>>> Hughes lost 34,000 subs in Q2 2025, ending with 819,000.
> Viasat's base
> > >>> of
> > >>>> fixed broadband subs has dipped to 172,000. Just this week,
> EchoStar
> > >>> execs
> > >>>> said Hughes Network Systems is pivoting to the enterprise
> market
> > >>>> <
> > >>>>
> > >>>
> >
> https://www.lightreading.com/satellite/echostar-execs-dish-on-company-s-forced-pivot-and-the-path-forward
> > >>>> as the residential side of its satellite business remains in
> decline.
> > >>>>
> > >>>> "Hughes and Viasat are still running TV advertising. They're
> still a
> > >>>> competitive and viable option but losing share pretty
> rapidly." Moore
> > >>> said.
> > >>>> Some Viasat and Hughes customers are defecting to Starlink,
> but most
> > of
> > >>>> Starlink's customers are leaving small rural telcos and
> cable
> > operators
> > >>> for
> > >>>> the satellite operator, Entner said. Overall, more than 85%
> of
> > >>> Starlink's
> > >>>> customers come from rural areas, while the rest are
> suburban,
> > according
> > >>> to
> > >>>> Recon Analytics data.
> > >>>>
> > >>>>
> > >>>> *Service and equipment price cuts*...
> > >>>>
> > >>>> [...]
> > >>>>
> > >>>>
> > >>>
> >
> https://www.lightreading.com/satellite/starlink-looking-less-niche-as-its-retail-presence-expands
> > >>>> --
> > >>>> Geoff.Goodfellow@iconia.com
> > >>>> living as The Truth is True
> > >>>> _______________________________________________
> > >>>> Starlink mailing list --starlink@lists.bufferbloat.net
> > >>>> To unsubscribe send an email
> tostarlink-leave@lists.bufferbloat.net
> > >>>>
> > >>> _______________________________________________
> > >>> Starlink mailing list --starlink@lists.bufferbloat.net
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> > >>>
> > > _______________________________________________
> > > Starlink mailing list --starlink@lists.bufferbloat.net
> > > To unsubscribe send an email tostarlink-leave@lists.bufferbloat.net
> >
> > --
> > ****************************************************************
> > Dr. Ulrich Speidel
> >
> > School of Computer Science
> >
> > Room 303S.594 (City Campus)
> >
> > The University of Auckland
> > u.speidel@auckland.ac.nz
> > http://www.cs.auckland.ac.nz/~ulrich/
> > ****************************************************************
> >
> >
> > _______________________________________________
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> >
> 
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> End of Starlink Digest, Vol 53, Issue 10
> ****************************************
>