From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bosmailout06.eigbox.net (bosmailout06.eigbox.net [66.96.189.6]) (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 7FFA73B2A4; Sun, 8 Aug 2021 00:20:34 -0400 (EDT) Received: from bosmailscan03.eigbox.net ([10.20.15.3]) by bosmailout06.eigbox.net with esmtp (Exim) id 1mCaIc-0002aN-2L; Sun, 08 Aug 2021 00:20:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=alum.mit.edu; s=dkim; h=Sender:Content-Transfer-Encoding:Content-Type: MIME-Version:Message-ID:Date:Subject:In-Reply-To:References:Cc:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=U9JkLY0INat6+Ewe0d8rhTpypZ5BH2bMCMB1HTSf48A=; b=TtHE/TfAmH45QG+LZXOQvrx9s9 1C3sBlAhrKZqoNnwe4nMisHU5oyyulBk10ZViECAmSEZEf+KSeMFBb3qbrp/YrihWU+QI1ilWvZtL O0q1dZIeDfOnEUSuRbo8UrZvVU0QA4SOpGbn43LvEYmX9Wu4+82yh99tx6BFhPnPSPsXe7roSUb+V woCgD5YvFU5VmwnA4QnLtyL3JZfzIKbHoOMkaTGzX8wiJa375imOy/B1Xr35YF/ETP057ly2XGlBI N7SLcAxKX9QaW9+7JwSQ+ZAPeDE2M0Tsxjef3gvv/d8I2et6Q61yMJTC1xJVopxqpRwhpQYw2nitw HA6U4h+A==; Received: from [10.115.3.32] (helo=bosimpout12) by bosmailscan03.eigbox.net with esmtp (Exim) id 1mCaIb-0006at-Q1; Sun, 08 Aug 2021 00:20:33 -0400 Received: from bosauthsmtp17.yourhostingaccount.com ([10.20.18.17]) by bosimpout12 with id esLW250010N5uqq01sLZCJ; Sun, 08 Aug 2021 00:20:33 -0400 X-Authority-Analysis: v=2.3 cv=d4VuNSrE c=1 sm=1 tr=0 a=f4kFLigMKr8AH7rIJ//qJA==:117 a=x+7tlP9+fMpTIVJEmcsKvw==:17 a=kj9zAlcOel0A:10 a=MhDmnRu9jo8A:10 a=Wo7qeYC63mUA:10 a=kurRqvosAAAA:8 a=ZdOKaNPWnYhI3Xz9-HgA:9 a=CjuIK1q_8ugA:10 a=kbxRQ_lfPIoQnHsAj2-A:22 Received: from c-73-222-32-85.hsd1.ca.comcast.net ([73.222.32.85]:62291 helo=SRA6) by bosauthsmtp17.eigbox.net with esmtpa (Exim) id 1mCaIX-0006Kh-JN; Sun, 08 Aug 2021 00:20:29 -0400 Reply-To: From: "Dick Roy" To: "'Leonard Kleinrock'" , "'David Lang'" Cc: , "'Make-Wifi-fast'" , "'Bob McMahon'" , "'Cake List'" , , "'cerowrt-devel'" , "'bloat'" References: <1625188609.32718319@apps.rackspace.com> <989de0c1-e06c-cda9-ebe6-1f33df8a4c24@candelatech.com> <1625773080.94974089@apps.rackspace.com> <8677F5C4-1893-4A61-A13C-3C8BE17CB789@cs.ucla.edu> In-Reply-To: <8677F5C4-1893-4A61-A13C-3C8BE17CB789@cs.ucla.edu> Date: Sat, 7 Aug 2021 21:20:17 -0700 Organization: SRA Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 Thread-Index: AdeLuSNoqzPg3tuuQlWLUOoeRuYbhAAUbHBg X-MimeOLE: Produced By Microsoft MimeOLE X-EN-UserInfo: f809475445fb8041985048e338e1a001:931c98230c6409dcc37fa7e93b490c27 X-EN-AuthUser: dickroy@intellicommunications.com Sender: "Dick Roy" X-EN-OrigIP: 73.222.32.85 X-EN-OrigHost: c-73-222-32-85.hsd1.ca.comcast.net X-Mailman-Approved-At: Mon, 09 Aug 2021 13:17:35 -0400 Subject: Re: [Make-wifi-fast] [Starlink] [Cake] [Cerowrt-devel] Due Aug 2: Internet Quality workshop CFP for the internet architecture board X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Aug 2021 04:20:34 -0000 -----Original Message----- From: Starlink [mailto:starlink-bounces@lists.bufferbloat.net] On Behalf Of Leonard Kleinrock Sent: Monday, August 2, 2021 5:38 PM To: David Lang Cc: starlink@lists.bufferbloat.net; Make-Wifi-fast; Bob McMahon; Cake List; codel@lists.bufferbloat.net; cerowrt-devel; bloat Subject: Re: [Starlink] [Cake] [Make-wifi-fast] [Cerowrt-devel] Due Aug 2: Internet Quality workshop CFP for the internet architecture board These cases are what my student, Fouad Tobagi and I called the Hidden Terminal Problem (with the Busy Tone solution) back in 1975. [RR] Also known as the "hidden node" problem! Len > On Aug 2, 2021, at 4:16 PM, David Lang wrote: > > If you are going to setup a test environment for wifi, you need to include the ability to make a fe cases that only happen with RF, not with wired networks and are commonly overlooked > > 1. station A can hear station B and C but they cannot hear each other [RR] Lots of reasons for that in the wireless world of mobility. > 2. station A can hear station B but station B cannot hear station A [RR] This is largely due to link imbalance. In TDD systems like Wi-Fi, time variability of the RF channels is also an issue that is dealt with by having turn around times that are much less than the "(de-)coherence time" of the channel. Link imbalance is largely due to differences in tx power and rx front end noise figure. Smart antenna technology makes this a bit more complicated, but the essentials are still the same. 3. station A can hear that station B is transmitting, but not with a strong enough signal to decode the signal (yes in theory you can work around interference, but in practice interference is still a real thing) [RR] Yes, energy can be detected at levels that are insufficient for decoding. That said, if you can't decode the signal, you generally cannot know who sent it :^))) > > David Lang > _______________________________________________ Starlink mailing list Starlink@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/starlink