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 793A63B2A4; Mon, 25 Sep 2023 04:11:29 -0400 (EDT) Received: from dlang-mobile (unknown [10.2.2.69]) by mail.lang.hm (Postfix) with ESMTP id 5C0371AE11E; Mon, 25 Sep 2023 01:11:28 -0700 (PDT) Date: Mon, 25 Sep 2023 01:11:28 -0700 (PDT) From: David Lang To: Dave Taht cc: "Luis A. Cornejo" , libreqos , Dave Taht via Starlink In-Reply-To: Message-ID: <4p971809-5o95-q69q-3r86-48r742ro3215@ynat.uz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Subject: Re: [Starlink] tarana strikes back 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, 25 Sep 2023 08:11:29 -0000 On Sun, 24 Sep 2023, Dave Taht via Starlink wrote: > My purpose in asking the list here was to ask if the analysis of cell > size was correct and reasonable (it certainly looked so to me), and > the economic argument that falls out of the resulting information > density seems compelling for designing hybrid fiber and wireless > networks of all sorts, not as an endorsement of tarana. > >>> https://www.taranawireless.com/a-comparison-of-next-generation-fwa-vs-leo-satellite/ >>> >>> Can anyone question these Starlink numbers for cell size, etc? I think they have the cell size reasonably accuarate (for now), But if the cell sizes were of fixed size and unable to be re-used, once there were enough satellites to provide global coverage, adding more would not provide any value. But even their first phase includes many times the number they needed to provide global coverage, so the assumptions around the capacity being fixed by the initial cell size and a single satellite covering it cannot be correct. I question the assumption that there will only be a single satellite serving the cell at a time. With directional antennas (including phased arrays) you can aim both your uplink and downlink. Even without having multiple satellites covering a single cell, you can shrink the cells by having the ground stations further from the center of the cell aim at different parts of the sky. Lower altitude satellites will have smaller cells with the same antennas, reducing the altitude from ~560km to ~340km reduces the spot size by ~2.5 so you get somewhere around 7 spots in the same footprint (and need less power, so you generate less interference to other cellss, so you can re-use the same frequency in closer proximity, a virtue cycle), it also reduces the latency. Larger satellites allow for physically bigger antennas, which increase the ability to focus, use less power on both ends, and be more immune to signals from the wrong direction, very similar to what the lower altitude gives you (without the decreased latency that the lower altitude provides) So in the big picture, they are correct with the basic idea that WISPs can outperform Starlink, the real questions are around where the crossover point is, and if WISPs are going to build out in enough areas. It doesn't matter if a WISP could outperform Starlink if they don't build it, or don't run sufficient capacity of wired Internet to the tower. WISP endpoint equipment could be cheaper than Starlink dishes (it's far simpler, but Starlink now has economies of scale kicking in that have reduced their production costs by 5x or better, even in the face of inflation, the early dishies were reported to cost ~$3k each to build, now with them selling for $600 (less in some places, don't know the average selling price) they are no longer losing money on each dishy sold. That's getting down into the price for the WISP endpoint equipment costs. and the WISP has to pay installers to setup that equipment as well as covering the hardware costs. This doesn't mean that Starlink will outperform WISPs in raw speed, but they may be cheaper in many areas, pushing the crossover point to denser population areas before it becomes congested enough for people to prefer the WISP David Lang