From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.lang.hm (syn-045-059-245-186.biz.spectrum.com [45.59.245.186]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6C3583B29D for ; Wed, 5 Jun 2024 00:26:25 -0400 (EDT) Received: from dlang-mobile (unknown [10.2.3.133]) by mail.lang.hm (Postfix) with ESMTP id 11ED71D3D9B; Tue, 4 Jun 2024 21:26:24 -0700 (PDT) Date: Tue, 4 Jun 2024 21:26:24 -0700 (PDT) From: David Lang To: Mike Puchol cc: Michael Richardson via Starlink In-Reply-To: Message-ID: References: <32AD770E-336E-4CF4-8B1B-8AE7353981CC@ieee.org> <9687.1717527495@obiwan.sandelman.ca> <1011428206.2534598.1717542074644@www.openxchange.eu> MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="===============4267129412448323299==" Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile 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: Wed, 05 Jun 2024 04:26:25 -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. --===============4267129412448323299== Content-Type: text/plain; format=flowed; charset=US-ASCII Mike Puchol wrote: > Yes, they correct doppler in a single stream - what I was alluding to is the > MIMO advantage of terrestrial networks which cannot be easily replicated from > multiple satellites, as the UE cannot correct multiple doppler shifts and > timing advances unless it implements an NTN-specific approach. I am thinking that the doppler correction will be the same (or very close to it) for everything in a single cell. now, timing that exact between multiple satellites is something I would see as a harder problem, but I'm not an expert there. David Lang > > Best, > > Mike > On Jun 4, 2024 at 20:17 -0700, David Lang , wrote: >> Mike Puchol wrote: >> >>> Something else that's much harder to implement is MIMO, as you don't get path >>> diversity from a satellite. AST claims they will do this by using more than >>> one satellite, however they haven't answered basic questions such as how will >>> the UE compensate the huge differences in doppler shift on top of the multiple >>> paths. >> >> for the starlink version, the satellite adjusts it's transmit/receive >> frequencies to correct for the doppler shift so that the phones don't need to. >> >> David Lang >> > --===============4267129412448323299== Content-Type: text/plain; CHARSET=utf-8 Content-Transfer-Encoding: BASE64 Content-ID: <641497o5-003r-r9o8-qr67-612994nrq975@ynat.uz> Content-Description: Content-Disposition: INLINE X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KU3Rhcmxpbmsg bWFpbGluZyBsaXN0ClN0YXJsaW5rQGxpc3RzLmJ1ZmZlcmJsb2F0Lm5ldApodHRwczovL2xpc3Rz LmJ1ZmZlcmJsb2F0Lm5ldC9saXN0aW5mby9zdGFybGluawo= --===============4267129412448323299==--