From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vsmx002.dclux.xion.oxcs.net (vsmx002.dclux.xion.oxcs.net [185.74.65.108]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id BF41E3CB37 for ; Mon, 3 Jun 2024 13:42:00 -0400 (EDT) Received: from proxy-8.proxy.shared.ns.xion.oxcs.net (proxy-8.proxy.shared.ns.xion.oxcs.net [104.133.2.105]) by mx-out.dclux.xion.oxcs.net (Postfix) with ESMTPA id 0073DA6098A; Mon, 3 Jun 2024 17:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=dclux.xion.oxcs.net; s=mail1; t=1717436519; bh=9JWV3+Ig4I9yHGCYqQ9g2GdDQPLRhBTZCEc410N2u+Q=; h=Date:From:To:Cc:In-Reply-To:References:Subject:From; b=VWY1m/NRZo+CnOM5iA1I4vDaUqdImBOhY3Z2D2WMmnTtUPp4SC8o8F3lhMUikLSQW FmAvUUGagOJ7AUDZzlJbw/k8zsFTrk2wvn6z8F0JqkKC+tj8ITTU3SZwis2MfE7kfQ 32z9ub/INr+lFJZt9kEIg/QK8lSJJxUJCgRSkRU1bXUBoAQbfRbhLzRgcrJ0+jRTCy ETNSHsTAU6KsMYqgfPXcmkMCABuJ3IV+CNFIfrQuWJz3QRYb5FnUCovF/C8oLQ0kkV Vg5+O7gswFyp2j+1mCVb4HdtjDdtyOSQrsT4Dsgb22IOspZcq6QreLu9ODbEtJw0Xg MN8Wcqj9FaGng== Date: Mon, 3 Jun 2024 10:41:35 -0700 From: Mike Puchol To: Ulrich Speidel , David Lang Cc: starlink@lists.bufferbloat.net Message-ID: In-Reply-To: <431q71ps-pp33-92q1-824o-16p148q5pp1o@ynat.uz> References: <00d881ed-682e-4ab9-8cad-ba5aea318251@auckland.ac.nz> <431q71ps-pp33-92q1-824o-16p148q5pp1o@ynat.uz> X-Readdle-Message-ID: f08df76c-f6ab-48ab-bcde-873554959ff1@Spark MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="665e005f_22c9c2f3_cadd" X-VadeSecure-Status: LEGIT X-VADE-STATUS: LEGIT Subject: Re: [Starlink] musk: 28ms median latency on starlink X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Jun 2024 17:42:00 -0000 --665e005f_22c9c2f3_cadd Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline While the terminals use focused beams, Starlink does not operate in isola= tion or using protected spectrum. They must comply with EP=46D limits, wh= ich are the reason why they just cannot land two co-frequency beams that = overlap, as they could be causing harmful interference to other users of = the same spectrum. Best, Mike On Jun 3, 2024 at 09:43 -0700, David Lang via Starlink , wrote: > If the ground stations were omnidirectional antennas, you would be corr= ect, but > since they are phased array directional antennas, they can steer the be= am to > receive one satellite even while a different one is transmitting on the= same > frequency to the same cell. > > David Lang > > > On Mon, 3 Jun 2024, Ulrich Speidel via Starlink wrote: > > > Date: Mon, 3 Jun 2024 22:40:24 +1200 > > =46rom: Ulrich Speidel via Starlink > > Reply-To: Ulrich Speidel > > To: starlink=40lists.bufferbloat.net > > Subject: Re: =5BStarlink=5D musk: 28ms median latency on starlink > > > > Getting the satellite density up will help, but it will only improve = things > > so far. > > > > The problem on user downlink in particular is that there's a limit on= the > > maximum spectral power flux density that arrives from the satellite i= n space > > on the ground. If you point all (mutually compatible) user downlink b= eams > > from a single satellite at a single cell, you all but reach that limi= t there. > > In fact, where SpaceX want to use two beams on the same frequency but= with > > opposite polarisations to the same cell, they must reduce the transmi= t power > > on each beam by 3 dB (50%) in order to stay within the limit. More sa= tellites > > would give you more beams, but you can't point them at cells that alr= eady > > have a beam on the same frequency in use from another satellite (unle= ss you > > de-rate on the power front, I guess). That seriously limits what you = can > > receive in terms of total capacity within a single cell to what a sin= gle > > satellite's mutually compatible beams can deliver, which appears to b= e about > > 12 Gb/s on V1 and V1.5 birds, and 20 Gb/s on V2 (on Ku, if you add in= Ka-band > > and anticipate Dishys that can do Ka, then it's a lot more for Ka). I= n > > practice, we know that a cell gets served by beams from different sat= ellites, > > but the overall constraint still applies - if you deploy beam X from = sat A > > and beam Y from sat B to the same cell, this makes the same contribut= ion to > > P=46D as deploying both from the same satellite. Note that Starlink s= ats do > > have multiple mutually incompatible beams that they can only point at= > > different cells, bringing Ku user downlink capacity up to 16 Gb/s on = V1 and > > 1.5, and 48 Gb/s on V2. But that only ups your chances of getting a l= arger > > slice of those 12 or 20 Gb/s in your cell. > > > > Your best bet for continuing good service at the moment is literally = to tell > > your neighbours that Starlink is useless, so they don't sign up and y= ou can > > have your cake all to yourself ;-) > > > > On 3/06/2024 5:13 am, Dave Taht via Starlink wrote: > > > Via elon musk: > > > > > > Starlink just achieved a new internal median latency record of 28ms= > > > yesterday=21 Great work by the engineering and operations teams. > > > > > > - https://twitter.com/elonmusk/status/1797282250574184587 > > > > > > I of course, am very interested in y'all=C2=B4s external measuremen= ts of how > > > well starlink is doing. =46or me, it is fantastic - 30Mbit uploads = nowadays, > > > 0 > > > latency on the upload (how=3F) > > > https://www.waveform.com/tools/bufferbloat=3Ftest-id=3D2a1d139b-87c= b-4ba4-a829-e2167801cffe > > > > > > I also keep hoping that the rest of the ISP industry is now paying > > > attention and deploying stuff like fq=5Fcodel and cake and libreqos= , but, ah > > > well - I will settle for starlink blowing past a lot of dsl and cab= le and > > > finding ways to get their density up. > > > > > > Anyone going to the Starship launch on the 6th=3F > > > > > > > > > > > > -- > > > https://www.youtube.com/watch=3Fv=3DBV=46WSyMp3xg&t=3D1098s > > > Waves= Podcast > > > Dave T=C3=A4ht CSO, LibreQos > > > > > > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F > > > Starlink mailing list > > > Starlink=40lists.bufferbloat.net > > > https://lists.bufferbloat.net/listinfo/starlink > > > > > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F > Starlink mailing list > Starlink=40lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink > > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F > Starlink mailing list > Starlink=40lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink --665e005f_22c9c2f3_cadd Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
While the ter= minals use focused beams, Starlink does not operate in isolation or using= protected spectrum. They must comply with EP=46D limits, which are the r= eason why they just cannot land two co-frequency beams that overlap, as t= hey could be causing harmful interference to other users of the same spec= trum.

Best,

Mike
On Jun 3, 2024 at 09:43 -0700, Davi= d Lang via Starlink <starlink=40lists.bufferbloat.net>, wrote:
If the ground stations were omnidirectional antennas, you would= be correct, but
since they are phased array directional antennas, they can steer the beam= to
receive one satellite even while a different one is transmitting on the s= ame
frequency to the same cell.

David Lang


On Mon, 3 Jun 2024, Ulrich Speidel via Starlink wrote:

Date: Mon, 3 Jun 2024 22:40:24 +1200
=46rom: Ulrich Speidel via Starlink <starlink=40lists.bufferbloat.net&= gt;
Reply-To: Ulrich Speidel <u.speidel=40auckland.ac.nz>
To: starlink=40lists.bufferbloat.net
Subject: Re: =5BStarlink=5D musk: 28ms median latency on starlink

Getting the satellite density up will help, but it will only improve thin= gs
so far.

The problem on user downlink in particular is that there's a limit on the=
maximum spectral power flux density that arrives from the satellite in sp= ace
on the ground. If you point all (mutually compatible) user downlink beams=
from a single satellite at a single cell, you all but reach that limit th= ere.
In fact, where SpaceX want to use two beams on the same frequency but wit= h
opposite polarisations to the same cell, they must reduce the transmit po= wer
on each beam by 3 dB (50%) in order to stay within the limit. More satell= ites
would give you more beams, but you can't point them at cells that already=
have a beam on the same frequency in use from another satellite (unless y= ou
de-rate on the power front, I guess). That seriously limits what you can<= br /> receive in terms of total capacity within a single cell to what a single<= br /> satellite's mutually compatible beams can deliver, which appears to be ab= out
12 Gb/s on V1 and V1.5 birds, and 20 Gb/s on V2 (on Ku, if you add in Ka-= band
and anticipate Dishys that can do Ka, then it's a lot more for Ka). In practice, we know that a cell gets served by beams from different satelli= tes,
but the overall constraint still applies - if you deploy beam X from sat = A
and beam Y from sat B to the same cell, this makes the same contribution = to
P=46D as deploying both from the same satellite. Note that Starlink sats = do
have multiple mutually incompatible beams that they can only point at
different cells, bringing Ku user downlink capacity up to 16 Gb/s on V1 a= nd
1.5, and 48 Gb/s on V2. But that only ups your chances of getting a large= r
slice of those 12 or 20 Gb/s in your cell.

Your best bet for continuing good service at the moment is literally to t= ell
your neighbours that Starlink is useless, so they don't sign up and you c= an
have your cake all to yourself ;-)

On 3/06/2024 5:13 am, Dave Taht via Starlink wrote:
Via elon musk:

Starlink just achieved a new internal median latency record of 28ms
= yesterday=21 Great work by the engineering and operations teams.

- https://twitter.com/elonmusk/status/1797282250574184587

I of course, am very interested in y'all=C2=B4s external measurements of = how
well starlink is doing. =46or me, it is fantastic - 30Mbit uploads nowada= ys,
0
latency on the upload (how=3F)
https://www.waveform.com/tools/bufferbloat=3Ftest-id=3D2a1d139b-87cb-4ba4= -a829-e2167801cffe

I also keep hoping that the rest of the ISP industry is now paying
attention and deploying stuff like fq=5Fcodel and cake and libreqos, but,= ah
well - I will settle for starlink blowing past a lot of dsl and cable and=
finding ways to get their density up.

Anyone going to the Starship launch on the 6th=3F



--
https://www.youtube.com/watch=3Fv=3DBV=46WSyMp3xg&t=3D1098s
<https://www.youtube.com/watch=3Fv=3DBV=46WSyMp3xg&t=3D1098s> W= aves Podcast
Dave T=C3=A4ht CSO, LibreQos

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