From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id BC49A3B2A4 for ; Thu, 14 Jul 2022 08:35:01 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1657802094; bh=YjBacB5cSznAEPzkJP4ra5ybik+DW9PE+pd5GocEZJY=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=DibeF68Ps9bb4fkkOODZXo5mwnZQT6zjkBJNE5U8Qv6VvObhb+8wp3pJe0ChiGQ8X NKuUHm6rRcdpKXSq2NURcgy5jDNY/1hHnJljH5YFmPylPrE7cx6orySlbaHAloWJJh QOLhEyUhz5mtAUxs7BCPH1tWrR0Qi7DgYCPYAFLI= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from smtpclient.apple ([134.76.241.253]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MVNAr-1o5C013NTT-00SOXE; Thu, 14 Jul 2022 14:34:54 +0200 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.100.31\)) From: Sebastian Moeller In-Reply-To: Date: Thu, 14 Jul 2022 14:34:53 +0200 Cc: Larry Press , David Lang , Dave Taht via Starlink Content-Transfer-Encoding: quoted-printable Message-Id: <0C0F0D5F-7CF6-412A-AD1A-392323ADB2FB@gmx.de> References: <20220713173602.0582c9b3@spidey.rellim.com> <92n4s129-6r15-7q75-7293-qpo73q298srn@ynat.uz> <841ca6dc-d6d3-46ab-87c0-d6bcaa31533b@Spark> <42D3F3C5-C1B3-48EA-8C45-2540ACD787E4@gmx.de> To: Mike Puchol X-Mailer: Apple Mail (2.3696.100.31) X-Provags-ID: V03:K1:ST0fZDovMqCavK41uCWq+xn7uf1gl3hVv2M9R0/ZPl/dRDaHOW3 J6vR9hFXb6jUk/D3rMmVeQ350mhf8fR3WzLoveLuDxepeq5+i6motyel/1jOWG6NEe1Luqi sin62v7XJXyMfbZwWits0tZTXcnLn0M4cTwDbVSYOZV4q4DkhcV3pJRRbAIJujQrlKEilck BKqXl8Jc2879Es2qS2YQQ== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:zeVeDLbq9W0=:V3vnrtdNrUMgXSZWe1ws9R BHKPn/slhumWzgGUe3FJD3q09OzxJI1/bMgT3/iyKBh/H/H/N2cDpxff+ZxZNmb4rgBqu1klB 3z7WI+XiBgamvz6fwMTRYHNWvYRtt7nNpZRpGdZJocC6f4AjlxI41fbHkhmSpYe8kdjgObM4P AlYf1m5BnwxzYZZXItLq83ZIDcYg/XTDHhSMLX4LsWer0zTyX88Jcn+YPhyyXa3SzBLcvp187 BNlkRErqcsytmYp38qnW00R/0NLC32kfrnNtHdJJ8D65L+M3VjLvL6Y0hEjfzsD5cNgwL26q0 2jBh7WvnNJYPS0/hPuDGbsiCPQS5yjzLNW1Gl8FEYu1pLgCistbqt6H+hKLqrTWbkWwrzb/v/ Lj8cSD/XfjECPv9q0eE1AxW3VPRLpMx+3FtthUVNe4n1qsQnj5VxwRLPiI/r7AAHBdW8Hr/ek YOLoG7korBEy7fYEonHxIdNHQ+egeDYZBEmBVPljUeoCoMHl0XfX5nTItxFwlRd009yDDilnl jAMrnxpEgiPgbWXn2sBo0oLgXOKtuwHTLYF/m4jYlkRO5uJI30+KmSGDZtkdAIf8bp11xfw66 vjt4lG3VDBjl2vn3guSSCRorkrYKNeBD9pIEy2ZDpsZABZPwDHt5X6lBAhosnJVTxlodvnG/D RluyBCug1lVE3FX+BiowZGFm3SKGguY1oHhU3NI3SQSh5M8Fb+o9jptYr+nF47Eznk78nq8xd QrkJUSXQom2u9nz9RWngpcFfG0i9kAj0rLum+7lZai2A20kA/GcSDLtCy4A70hrDpG0ldEzmN 9kPcVjqkUeCxmipfrEWla49XyT68il+qk8f8M9v7MjJGl0DRyp/2IDqo3eB1m+Pk68Wy9IuVD 27Njy4N5pALcsM3ggkTAy4nf1Emmdwh8G8UYO9pRR1Cyo0upKIqLbowxXp63UjjB1kBqQ+S7M M2IfdX+Pb1xBZxnNp0Q4fk7f8kB8+N/JFH9tnOKj6zbz0Uru+gwNAZ3xvS+JM7tXcMyyAj+Cj bo+xoRwvqdtFVyXKHM2BgLPv4CqDW59PzZn9/5Z6p6p0uLjmSlk8b1nErdx/KcEtCLkV4GGYo RNkyV6X8OlJrq5+llweyLPxyjJGU2BR0NkbXqgLwGuPRR1zHwoX86UqpA== Subject: Re: [Starlink] starlink at sea 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: Thu, 14 Jul 2022 12:35:02 -0000 Hi Mike. Thanks a lot. This is intersting. > On Jul 14, 2022, at 14:02, Mike Puchol wrote: >=20 > The uplink is an OFDM signal with 128 subcarriers, looking at the = signal in the time domain reveals a frame length corresponding to 14% = (from memory, 1,1 us frame vs 6.7 us pause). I have two terminals 1 = meter apart and they can each achieve 30 Mbps at the same time over the = same uplink channel. I would expect the satellite to assign a particular = set of slots to a terminal. So assuming the 30 Mbps being gross rate and not measured = goodput: 30Mbps -> 30 / (1.1/(6.7+1.1)) =3D 212.73 Mb/s while actively sending, = and=20 1000000=C2=B5s/s / (6.7+1.1)=C2=B5s =3D 128205.128205 slots/sec (30 / (1.1/(6.7+1.1))) * 1000^2 / (1000000 / (6.7+1.1)) =3D 1659.27 = bits/slot 1659.27/8 =3D 207.41 Bytes/slot with 128 subcarriers that would be approximately an average=20 1659.27/128 =3D 12.96 or ~ 13 bit/subcarrier=20 if all carriers are loaded equally (which is unlikely, I expect some = re-arrangement ot bits between subcarriers to account for different = levels of noise and what not). > If there are any OFDM blind analysis experts in the room, shout! Please do! Regards Sebastian >=20 > Best, >=20 > Mike > On Jul 14, 2022, 13:33 +0200, Sebastian Moeller , = wrote: >> Hi Mike, >>=20 >>> On Jul 14, 2022, at 13:15, Mike Puchol via Starlink = wrote: >>>=20 >>> On the multiple terminals, I have verified that the duty cycle of a = consumer terminal is 14%, thus, you could have 7 terminals on a single = uplink channel with some guard time. >>=20 >> Could you elaborate how that works.how the terminals will be = interleaved in that situation? >>=20 >> Regards >> Sebastian >>=20 >>=20 >>> I have seen 30 Mbps up, so you=E2=80=99d be able to push 210 Mbps in = uplink, or a spectral efficiency of about 3.4 bps/Hz. >>=20