From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-x112f.google.com (mail-yw1-x112f.google.com [IPv6:2607:f8b0:4864:20::112f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 171263B29E; Tue, 26 Sep 2023 19:06:03 -0400 (EDT) Received: by mail-yw1-x112f.google.com with SMTP id 00721157ae682-59e77e4f707so121280967b3.0; Tue, 26 Sep 2023 16:06:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695769562; x=1696374362; darn=lists.bufferbloat.net; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=i7xK5HuRLGi3TgYwAZmSHxuS0OcbZTllbO801KHsmIc=; b=IbIW9HC8o+b2DxKbJsS4ejO/g3LDf6czysUcRzP6PQ4YPxUU7j0lUqhGW23CGevCh9 eyftnD9poqCVPDcFxx6XTfLQeRwyNse+3YkDq1ch3fhDRPKM5UvtuGIDoLdQv9Grt11X IEEgJsMF9EMgSdfMx6ecRLfb4Nd6JVA8P29WWTRamLvEgIycnhHBhAJv7hwun9OOsgFt PmGdODtYIxkqoZx5pXUTNTlug4R5s4cuvH/OA1nTg/1wPd4DvLu61YcQT/AVbwW0aOQE Heurr+R36OB68lgt91lCVIhSNH5At3U5UxRO8nwbYwx6osSygkb7+jwi+vPP4dNRA13r FgUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695769562; x=1696374362; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=i7xK5HuRLGi3TgYwAZmSHxuS0OcbZTllbO801KHsmIc=; b=qM4gmu6Gqbm//dVN51DDqvfANNKKipCXUPHYRT5FQYrjWXCyHPOsDrpT8be9tVtj1J VVtafoZ25YB3xGEfij8nQMHyrMGNffmax8rKL7UW+UTY6IwPW5Wm0/se/ISjeGLh9tY5 0uDkH1NLrvc76MdjmtezzO+Hob27h36nzv2RTR9r0tlz+AP4h9Mm3M0vV/oZMhXIBSIW Ka96m167+Md/gEv/BepWxAqNKUMze7oiVKY0NRvVFfz+RZ+lQah16Z6BAARi8eAt/IkB rasZGzMLxzv6i9/MIzP4EjfMkOyaoDtE9o/7FLREuw8GQ7rsJKspQ28dyIUSPYWYuxdQ KzqQ== X-Gm-Message-State: AOJu0YxB1EclzzICGPHWW9Yxgmo4BG9aAWeEiDgFZRlcO7ywL3oF10w7 lArBIJgCd9q1FwjbGUJwI7XQrhOgNVl6kRzhB90= X-Google-Smtp-Source: AGHT+IEc6+Tm2ETUenH8m1hN17hrvdstV1HV094FpMA7SifEdRbMuK62ErVKkeJgT+9bOM051c7BB3c6xTy4w15ew9k= X-Received: by 2002:a81:5c54:0:b0:595:89b0:6b41 with SMTP id q81-20020a815c54000000b0059589b06b41mr448373ywb.38.1695769562303; Tue, 26 Sep 2023 16:06:02 -0700 (PDT) MIME-Version: 1.0 References: <4p971809-5o95-q69q-3r86-48r742ro3215@ynat.uz> <9q304pqs-778s-2s16-455s-604qnn43082q@ynat.uz> In-Reply-To: <9q304pqs-778s-2s16-455s-604qnn43082q@ynat.uz> From: dan Date: Tue, 26 Sep 2023 17:05:51 -0600 Message-ID: To: David Lang Cc: Jim Forster , Dave Taht via Starlink , libreqos , "Luis A. Cornejo" Content-Type: multipart/alternative; boundary="00000000000061d03706064b1eab" Subject: Re: [LibreQoS] [Starlink] Starlink cell capacity (was; tarana strikes back) X-BeenThere: libreqos@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Many ISPs need the kinds of quality shaping cake can do List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Sep 2023 23:06:03 -0000 --00000000000061d03706064b1eab Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I'd like to question those numbers as stated by Tarana. Firstly, no provider can possibly get 100% utilization based on average use. If average use is 10M and you have 2200Mbps on an AP, you can only possibly serve 220 users that have 10Mbps plans. If you have 100Mbps plans you cannot have 220 users though as there has to be a substantial reserve to accommodate their bursty traffic up to plan speed. From our networks, I would say this is approximately 1 maximum plan speed reserved every 25 subscribers. I am of course just picking on a single AP, Tarana has pitched a 4 APs per tower all using the same frequency (which is a really nice trick) aka 'reuse of 1' so you can multiple any numbers I say here by 4 to accommodate a full tower and you could potentially double that and have 8 Tarana APs on a tower and then triple that when 6Ghz is available and so on. So 100 subscribers with 100M plans needs a ~400Mbps reserve. This is well supported in our statistics and lots of operators will land at a somewhat similar number when looking at their oversells. Of Tarana's 2200M stated speeds (which are more like 1400 per operators I've talked to but I digress...) 400Mbps per 100 subs needs to be scraped off the top and you need 1000M for average use, so that's fine at 1400M needed to 2200M claimed (but again, many operators will say 1400M available so..... about a 100x100M subscribers on this math). however, 200 subs is 2Gbps use but needs an 800Mbps reserve so that's well oversold and the AP will certainly see congestion during peak hours. 2800M needed on 2200M *or* 2800M needed on 1400M... Likely nightly congestion that could be 50% of sold capacity. Now, in support of Tarana's claims. LEO satellites have a much more limited geometry to work with, with a service cone of not more than about 15% of the satellites' view being of earth, the rest being of space.... which. means the antenna has to handle far more in far less. Terrestrial towers however have up to 360 degrees and up to about 50 degrees in elevation, only blocked by obstructions and tarana's tech overcomes a good part of that. At the borders of that service area, build another tower. LEO can try to put more satellites up, but these satellites are broadcasting down and even with really advanced beamforming each one creates more noise at the ground stations. They also need to have at least about 20 degrees separation for the ground stations to effectively utilize beamforming and nulling to avoid the noise. ie, it's not so simple to just add more LEO birds and get linear results, however it is relatively easy to add more towers and get a linear increase in capacity because client radios tend to be facing away from all towers except the one they are aimed at. There are definitely use cases for both techs, but if we're talking about capacity in any given area with enough population to support terrestrial towers, there really is no competition, terrestrial can out perform LEO by an order of magnitude because geometry says so. however, LEO gear like starlink is a godsend for people that are outside of that footprint. I can rant all day about the inherent limitations to LEO based purely on physics as well as the absolute requirement for dedicated spectrum that is much better handled with terrestrial towers but I'll save you all's eyes. On Tue, Sep 26, 2023 at 1:00=E2=80=AFPM David Lang via LibreQoS < libreqos@lists.bufferbloat.net> wrote: > On Tue, 26 Sep 2023, Jim Forster wrote: > > > This is all true (as much as I understand), Worth noting as well, is > that with > > LEOs if one satellite is maxed out serving a cell, then getting a secon= d > > satellite to help with that cell mean adding *lots* more satellites. If > > adjacent cells had very different loads then I guess nearby unloaeded > > satellites could help out their busy neighbors. But areas with busy > cells > > close together would mean doubling the number of satellites and > therefore > > platform Capex. Whereas terrestrial towers can be densified in busy > areas. > > In 2021 when SpaceX had launched 1800 satellites they said that once all > of them > reached operational altitude they would be able to provide global coverag= e. > > They now have >4k satellites in operation and (if fully approved) are > aiming at > ~10x that number eventually. That leaves a lot of additional satellites t= o > provide additional coverage for busy cells or smaller cells. > > I agree terrestrial towers can be densified more easily in a specific are= a. > > I'm saying that the crossover point where the density favors terrestrial > towers > is significantly denser than the original author was stating. (and as mor= e > sats > are launched, will move further) > > There's also the fact that satellite densification covers all areas, wher= e > terrestrial tower densification only covers that area. So around the > already > dense areas, you will have tower densification happening, pushing out, > leveraging the nearby wired infrastructure. But you may see a different > situation in areas where small communities are growing and you have to > setup the > tower and wired infrastructure from scratch. > > scenario: > > a village that is a 30 min drive from the next community and doesn't > have much fiber run to it. As it grows, you can't just put in towers > without > also running tens of miles of fiber to the area, so densification of > towers in > the area is significantly harder than seeing the suburbs of a large city > grow > where fiber is just a couple miles away. > > David Lang > _______________________________________________ > LibreQoS mailing list > LibreQoS@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/libreqos > --00000000000061d03706064b1eab Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I'd like to question those numbers as stated by Tarana= .

Firstly, no provider can possibly get 100% utilization based on av= erage use.=C2=A0 If average use is 10M and you have 2200Mbps on an AP, you = can only possibly serve 220 users that have 10Mbps plans.=C2=A0 =C2=A0If yo= u have 100Mbps plans you cannot have 220 users though as there has to be a = substantial reserve to accommodate=C2=A0their bursty traffic up to plan spe= ed.=C2=A0 From our networks, I would say this is approximately 1 maximum pl= an speed reserved every 25 subscribers. I am of course just picking on a si= ngle AP, Tarana has pitched a 4 APs per tower all using the same frequency = (which is a really nice trick) aka 'reuse of 1' so you can multiple= any numbers I say here by 4 to accommodate=C2=A0a full tower and you could= potentially double that and have 8 Tarana APs on a tower and then triple= =C2=A0that when 6Ghz is available and so on.

So 100 subscribers with= 100M plans needs a ~400Mbps reserve.=C2=A0 This is well supported in our s= tatistics and lots of operators will land at a somewhat similar number when= looking at their oversells.
Of Tarana's=C2=A02200M stated speeds (w= hich are more like 1400 per operators I've talked to but I digress...) = 400Mbps per 100 subs needs to be scraped off the top and you need 1000M for= average use, so that's fine at 1400M needed to 2200M claimed (but agai= n, many operators will say 1400M available so..... about a 100x100M subscri= bers on this math).=C2=A0 however, 200 subs is 2Gbps use but needs an 800Mb= ps reserve so that's well oversold and the AP will certainly see conges= tion during peak hours.=C2=A0 2800M needed on 2200M *or* 2800M needed on 14= 00M...=C2=A0 Likely nightly congestion that could be 50% of sold capacity.<= br>
Now, in support of Tarana's claims.=C2=A0 LEO satellites have a = much more limited geometry to work with, with a service cone of not more th= an about 15% of the satellites' view being of earth, the rest being of = space.... which. means the antenna has to handle far more in far less.=C2= =A0 Terrestrial towers however have up to 360 degrees and up to about 50 de= grees in elevation, only blocked by obstructions and tarana's tech over= comes a good part of that.=C2=A0 At the borders of that service area, build= another tower.=C2=A0 LEO can try to put more satellites up, but these sate= llites=C2=A0are broadcasting down and even with really advanced beamforming= each one creates more noise at the ground stations.=C2=A0 They also need t= o have at least about 20 degrees separation for the ground stations to effe= ctively utilize beamforming and nulling to avoid the noise.=C2=A0 =C2=A0ie,= it's not so simple to just add more LEO birds and get linear results, = however it is relatively easy to add more towers and get a linear increase = in capacity because client radios tend to be facing away from all towers ex= cept the one they are aimed at.

There are definitely use cases for b= oth techs, but if we're talking about capacity in any given area with e= nough population to support terrestrial towers, there really is no competit= ion, terrestrial can out perform=C2=A0LEO by an order of magnitude because = geometry says so.=C2=A0 =C2=A0 however, LEO gear like starlink is a godsend= for people that are outside of that footprint.

I can rant all day a= bout the inherent limitations to LEO based purely on physics as well as the= absolute requirement for dedicated spectrum that is much better handled wi= th terrestrial towers but I'll save you all's eyes.

On Tue, Sep 26, = 2023 at 1:00=E2=80=AFPM David Lang via LibreQoS <libreqos@lists.bufferbloat.net> wrote:
On Tue, 26 Sep 202= 3, Jim Forster wrote:

> This is all true (as much as I understand), Worth noting as well, is t= hat with
> LEOs if one satellite is maxed out serving a cell, then getting a seco= nd
> satellite to help with that cell mean adding *lots* more satellites. I= f
> adjacent cells had very different loads then I guess nearby unloaeded =
> satellites could help out their busy neighbors.=C2=A0 But areas with b= usy cells
> close together would mean doubling the number of satellites and theref= ore
> platform Capex.=C2=A0 Whereas terrestrial towers can be densified in b= usy areas.

In 2021 when SpaceX had launched 1800 satellites they said that once all of= them
reached operational altitude they would be able to provide global coverage.=

They now have >4k satellites in operation and (if fully approved) are ai= ming at
~10x that number eventually. That leaves a lot of additional satellites to =
provide additional coverage for busy cells or smaller cells.

I agree terrestrial towers can be densified more easily in a specific area.=

I'm saying that the crossover point where the density favors terrestria= l towers
is significantly denser than the original author was stating. (and as more = sats
are launched, will move further)

There's also the fact that satellite densification covers all areas, wh= ere
terrestrial tower densification only covers that area. So around the alread= y
dense areas, you will have tower densification happening, pushing out,
leveraging the nearby wired infrastructure. But you may see a different situation in areas where small communities are growing and you have to setu= p the
tower and wired infrastructure from scratch.

scenario:

a village that is a 30 min drive from the next community and doesn't have much fiber run to it. As it grows, you can't just put in towers wi= thout
also running tens of miles of fiber to the area, so densification of towers= in
the area is significantly harder than seeing the suburbs of a large city gr= ow
where fiber is just a couple miles away.

David Lang
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LibreQoS mailing list
LibreQo= S@lists.bufferbloat.net
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