[CalFiber] Fiber Broadband Association study on the capacity limits of Starlink

Christopher Mitchell christopher at ilsr.org
Fri Mar 5 11:46:14 PST 2021


Perhaps I mistyped but the Starlink folks have told me they are not limited
to 4 per satellite. They said they don't know what the upper limit is.

On Fri, Mar 5, 2021, 1:39 PM Ernesto Falcon <ernesto at eff.org> wrote:

> My prediction as to why its 4,
>
>
>
> Each spot beam takes up real estate on the satellite via an antennae, so
> that 4 limit is probably a physical space challenge (plus weight). Antenna
> lengths are controlled by the frequency you use to transmit, though a lot
> of smart engineering has made it where it doesn’t have to be a straight
> antenna like an old school radio. But they can’t just make smaller antennas
> because this is baked in physics, they have to figure out how to configure
> it where it can use the frequencies they are assigned in more clever ways
> like how smart phones wrap it around the handheld. And technological
> advancements will have to wait till a large part of the satellite fleet is
> retired as old ones are cycled out new ones every handful of years.
>
>
>
> Satellite TV has this same challenge with local broadcast channels. Each
> satellite can only cover so many local markets because of the number of
> spot beams each can hold. They have to keep the old satellites going for
> years until they get decommissioned and replaced by a new satellite with
> new advancements in spot beam tech, so you have lags where you have
> satellite TV being transmitted in 2021 with 2016 tech. Unlike broadband,
> satellite TV advancements came with more efficient compression of TV stream
> distribution, so essentially using less data to achieve the same results,
> which meant fewer spot beams can cover more area with the same capacity. I
> don’t think that option is available for download/uploads.
>
>
>
> Unrelated but interesting note about Starlink. One of my friends who is
> beta testing now sent me some updates. It’s a solid 100/15 mbps, which is
> great as a basic service. But the thing I didn’t account for but makes
> sense is his Internet goes out at set intervals for about 15 seconds.
> That’s the delay between one satellite passing over his connection then
> losing line of sight and the next satellite coming to pick up the
> connection. That’ll be fixed with more satellites to ensure there isn’t a
> break of line of sight, but basically non-live streaming Internet activity
> is a non-starter but Internet activities that can buffer work great. Just
> delivering consistent connectivity adds costs to Starlink via more rocket
> launches before we even get to increasing capacity.
>
>
>
> *From: *Christopher Mitchell <christopher at ilsr.org>
> *Date: *Friday, March 5, 2021 at 11:01 AM
> *To: *Ernesto Falcon <ernesto at eff.org>
> *Cc: *calfiber at lists.eff.org <calfiber at lists.eff.org>
> *Subject: *Re: [CalFiber] Fiber Broadband Association study on the
> capacity limits of Starlink
>
> Someone more technical than me can correct me but I think the spectrum
> limitation is per spot beam and they told me that they don't think they are
> limited to 4 spot beams per satellite. Each spot beam is 5 gbps I think.
> Currently they have 4 spot beams per satellite I think.
>
>
>
> On Thu, Mar 4, 2021, 4:54 PM Ernesto Falcon <ernesto at eff.org> wrote:
>
> Other than more spectrum or more satellites, I am not sure there is
> another realistic way to have the kind of doubling of capacity in the
> satellite system to stay ahead of trends in consumption. We see that with
> cell towers now where its densification or more auctions. And the doubling
> of consumption every handful of years is a recorded trend that isn’t
> changed yet, so I don’t think the 20-30% estimate is bad assumption here on
> what to predict.
>
>
>
>
>
> --
>
> Ernesto Omar Falcon
>
> Senior Legislative Counsel
>
> Electronic Frontier Foundation
>
> Office: 415 436 9333 ext. 182
>
> Cell: 202 716 0770
>
>
>
> *From:* Christopher Mitchell <christopher at ilsr.org>
> *Sent:* Thursday, March 4, 2021 2:14 PM
> *To:* Ernesto Falcon <ernesto at eff.org>
> *Cc:* calfiber at lists.eff.org
> *Subject:* Re: [CalFiber] Fiber Broadband Association study on the
> capacity limits of Starlink
>
>
>
> I mentioned this on the call I think some time ago... I don't think the
> assumptions are very credible. It may be that Starlink will have problems,
> but I don't think the Starlink folks expect to have the limitations that
> this analysis assumes, like the max capacity per satellite.
>
>
>
> I'm not taking a position on whether Starlink should be subsidized and I
> damn sure hate the way it is subsidized today - it harms some rural folks
> much more than others.
>
>
>
> Christopher Mitchell
> Director, Community Broadband Networks
> Institute for Local Self-Reliance
>
>
> MuniNetworks.org <http://www.muninetworks.org/>
>
> @communitynets
>
> 612-545-5185
>
>
>
>
>
> On Thu, Mar 4, 2021 at 2:47 PM Ernesto Falcon <ernesto at eff.org> wrote:
>
> This just came across my desk and was filed at the FCC earlier.
>
>
>
> It projects that by 2028 Starlink’s capacity will start to hit its limits
> when measured against 20-30% annual growth in consumption needs, which
> sounds right to me. It is this question of whether your network has the
> capacity to stay ahead of the demand curve for the long run is why I wrote
> this piece (
> https://www.eff.org/deeplinks/2020/06/why-slow-networks-really-cost-more-fiber)
> since often the slower capacity constrained providers will argue that they
> are * cheaper* than fiber so give them the tax money to build.
>
>
>
> This is part of the larger fight over whether the federal government
> should be subsidizing Starlink at all.
>
>
>
> --
>
> Ernesto Omar Falcon
>
> Senior Legislative Counsel
>
> Electronic Frontier Foundation
>
> Office: 415 436 9333 ext. 182
>
> Cell: 202 716 0770
>
>
>
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> CalFiber at lists.eff.org
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>
>
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