From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; spf=pass smtp.mailfrom=lang.hm; dkim=fail; arc=none (Message is not ARC signed); dmarc=none Received: from mail.lang.hm (wsip-70-167-213-146.ph.ph.cox.net [70.167.213.146]) by mail.toke.dk (Postfix) with ESMTPS id 9D15CC2C13D for ; Wed, 28 Jan 2026 04:30:41 +0100 (CET) Received: from [10.2.2.53] (unknown [10.2.2.53]) by mail.lang.hm (Postfix) with ESMTP id 7F3C6218CCE; Tue, 27 Jan 2026 19:30:39 -0800 (PST) Date: Tue, 27 Jan 2026 20:30:34 -0700 (MST) From: David Lang To: Ulrich Speidel cc: David Lang , Michael Richardson , starlink@lists.bufferbloat.net In-Reply-To: <3be747c6-793e-4b44-b1e1-52ee7ba9b6b0@auckland.ac.nz> Message-ID: References: <176851123059.1249.8585659892308012167@gauss> <5ea10a2c-4549-4d7f-9563-c5dc590857b0@auckland.ac.nz> <13187.1768590201@obiwan.sandelman.ca> <1412cd78-ec8e-487f-8086-6ea51b4301a5@auckland.ac.nz> <915noro0-sso2-6p29-oon5-3ss407p3957q@ynat.uz> <5d295a00-3563-4e22-922c-923398d6591d@auckland.ac.nz> <32179q5n-7nr7-q861-4s70-337519804np5@ynat.uz> <3be747c6-793e-4b44-b1e1-52ee7ba9b6b0@auckland.ac.nz> MIME-Version: 1.0 Message-ID-Hash: 7VFCXMEBNARB4VVBC4F6GIYECAL3NHB5 X-Message-ID-Hash: 7VFCXMEBNARB4VVBC4F6GIYECAL3NHB5 X-MailFrom: david@lang.hm X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; format=flowed; charset=ISO-8859-15 X-Content-Filtered-By: Mailman/MimeDel 3.3.10 X-Mailman-Version: 3.3.10 Precedence: list Subject: [Starlink] Re: Starlink and Iran List-Id: "Starlink has bufferbloat. Bad." Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Ulrich Speidel wrote: > Either way, it's worth noting here that while the relationship between=20 > transmit power and and received power is linear, the relationship between= =20 > received power and achievable bit rate is logarithmic in nature. For thos= e=20 > not so mathematically inclined: Starlink is starting off with 64QAM (6 bi= ts=20 > per symbol) at current EPFD limits, and each extra bit beyond that requir= es a=20 > doubling of the received power. Turning up the volume is not a game you c= an=20 > stay ahead in for long, regardless of regulatory constraints. I think that the value in allowing higher radiated power at the receive end= =20 isn't to increase the bit rate from a single satellite, but to allow multip= le=20 satellites to cover the same area with the beam steering on the receiver=20 differentiating between the satellites. allowing two satellites with significantly different angles to cover the sa= me=20 area allows for (close to) 2x the aggregate bandwidth to spread between all= =20 receivers in that area. > Some interesting tidbits from the grant document though: > > * 4. a. No more than 8 satellite beams "in the same frequency" (I > presume there's the word "band" missing here) into the same or > overlapping areas at a time. That means at most 8 beams per cell. if that's a step up from a single beam, that will allow for close to 8x the= =20 aggregate bandwidth. And if they can show (over time) that this doesn't cause problems, it will = be=20 reasonable to expect raising this limit over time it may be band, or it may be frequency/channel (like wifi has 3 bands, 2.4G= , 5G,=20 6G), but 5G has many non-overlapping channels, and operating on multiple=20 channels at the same time is quite reasonable for high-end APs > * 4. b. "SpaceX must maintain a minimum GSO arc exclusion zone of at > least four (4) degrees with=A0respect to operational GSO satellites". > Finally a clear word? that geo exclusion has been in place for a while, but I thought it was a lo= t=20 wider than 8 degrees (4 degrees to each side) I seem to remember hearing 25= =20 degrees being thrown around in discussions (I may very well be misrememberi= ng) David Lang