From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.lang.hm (unknown [66.167.227.145]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id A1C213B2A4 for ; Fri, 15 Sep 2023 13:52:57 -0400 (EDT) Received: from dlang-mobile (unknown [10.2.2.69]) by mail.lang.hm (Postfix) with ESMTP id B83D71AB819; Fri, 15 Sep 2023 10:52:56 -0700 (PDT) Date: Fri, 15 Sep 2023 10:52:56 -0700 (PDT) From: David Lang To: Ulrich Speidel cc: starlink@lists.bufferbloat.net In-Reply-To: Message-ID: <0q3n1sp5-09r5-5pqn-3p9p-opq883305s1s@ynat.uz> References: <2d05e701-7556-8ae4-122c-e2f2d23feff2@gmail.com> <4o116qp9-6108-91r8-pn91-o37o6629npqo@ynat.uz> <2012b68c-2e15-4b5c-b36b-3b1d7eff12b4@gmail.com> MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="===============4667205838241976300==" Subject: Re: [Starlink] Main hurdles against the Integration of Satellites and Terrestial Networks 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: Fri, 15 Sep 2023 17:52:57 -0000 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --===============4667205838241976300== Content-Type: text/plain; format=flowed; charset=US-ASCII On Sat, 16 Sep 2023, Ulrich Speidel via Starlink wrote: > On 15/09/2023 11:29 pm, Alexandre Petrescu via Starlink wrote: >> >> I must say that I dont know whether the original 'DISHY' is simply a >> dish antenna with an analog amplifier and maybe some mechanical motor >> steering, or whether DISHY includes a computer to execute some protocol, >> some algorithm. In addition to that Ulrich says, the dishy is a full computer, it's output is ethernet/IP and with some adapters or cable changes, you can plug it directly into a router. There are numberous teardown videos on youtube now, for both the original and the 1st of the rectangular dishys, they will show you how complex the system is. David Lang > > It's a phased array, not a dish, even if it looks like one. It consists of > 100's of fingernail-sized antenna elements that: > > * during transmissions, have an individual phase delay added to the > signal transmitted from that element, in order to permit > transmission of the combined signal from all elements into a > particular direction. > * during reception, have an individual phase delay added to the signal > collected by that element, before the signals are added to obtain > the combined received signal. This allows reception from a > particular direction. > > Dishy's main direction of transmission / reception is therefore not its > surface normal - this simply points to the area of the sky where Dishy > expects to see most satellites (a function of geographical latitude and > constellation design - essentially straight up in the tropics, and elsewhere > in the direction of the 53rd parallel, which corresponds to the predominant > orbital inclination in the Starlink fleet). The actual tracking is then done > with the phased array without mechanical movement by Dishy. > > From what I've seen, Dishy seems to consume more power on receive than on > transmit - that's if you actually download stuff. This is somewhat > counter-intuitive if you're used to putting link budgets together. But I'd > attribute that to a higher degree of digital signal processing required on > the receive and demodulation path. > > --===============4667205838241976300== Content-Type: text/plain; CHARSET=utf-8 Content-Transfer-Encoding: BASE64 Content-ID: <6966rro8-2p6s-1211-4o97-0063633o8r70@ynat.uz> Content-Description: Content-Disposition: INLINE X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KU3Rhcmxpbmsg bWFpbGluZyBsaXN0ClN0YXJsaW5rQGxpc3RzLmJ1ZmZlcmJsb2F0Lm5ldApodHRwczovL2xpc3Rz LmJ1ZmZlcmJsb2F0Lm5ldC9saXN0aW5mby9zdGFybGluawo= --===============4667205838241976300==--