From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 1BA3C3CB38 for ; Mon, 2 Aug 2021 20:02:01 -0400 (EDT) Received: by mail-ed1-x52e.google.com with SMTP id cf5so15224784edb.2 for ; Mon, 02 Aug 2021 17:02:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=btSi4O6LEIeLftPgnkPpzdBe3f6/kd1XBtERGxCiQtU=; b=TcIu6/efQDdVPrklEKdG5gz136AB78m6kmWYVEzdDyShPiBIlHW0Zpld5JQG5sSCkp sLrEl0sH7eyeKbZQH96lncwhrualL6c4pk81KimUaoSrqpW8oIYeUMV8lUeD/HufnnX4 DY0UCe+HiQcCUMmaeC93/m9uZ4p/geDehPvCg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=btSi4O6LEIeLftPgnkPpzdBe3f6/kd1XBtERGxCiQtU=; b=cjHpVTeiXNfvOZpL6WGEm5Ts/F0k8Rjz3BMPnURfn9a9X1N4JohwjtliZ0RTsNI17M Iz47q9Ssto3S4PvrC1IW1r3gVSZ8eXPUII9J4+r6p5A+cWQrBXjT3lfU4n4M+7sQU7zm fL8w3+lSWQXXo6a7JxKf17k7HOj2NeKJNx0b2gppMnaBJcihrCtdj1e4VOfRotM+dkvv snTcz34t0hyp0ZWNK6ukvlPgDz0rikvAA2C0JIG/gwNclnaoGUGC3HqH+9RYL3ZcuxUf 5O556pZ5HgkZMX+LJQu3L2zoX+2Ew0kH8L9oa0gsgcxrY5QHeR3P6vQGP89S9f8fduL7 SfMA== X-Gm-Message-State: AOAM531U1qDHtbArezDgZ/pYgOdJe/bJy6ZwDWdmGNrAugPQh9i7YU7i twL4hu3pSFjGKgYdolcMnVmcg/GqdloJ5ssmE/lXeucYCdFZBGx6RD8uBWgqphcxJDNgPhxN5Y3 ETPI0pmtG683IiK6VV958ZjdTYeXR2moVKP+PZ1op X-Google-Smtp-Source: ABdhPJy5LAWYSFeUeLgyAarucCSzdjfYVaxDP3o3F0TexOfxF2m9QRy2vl8+/5xCJ+5f4wmY9QQh7TFnpOe1NVdMR6A= X-Received: by 2002:aa7:d6cf:: with SMTP id x15mr22058883edr.59.1627948919951; Mon, 02 Aug 2021 17:01:59 -0700 (PDT) MIME-Version: 1.0 References: <1625188609.32718319@apps.rackspace.com> <989de0c1-e06c-cda9-ebe6-1f33df8a4c24@candelatech.com> <1625773080.94974089@apps.rackspace.com> In-Reply-To: From: Bob McMahon Date: Mon, 2 Aug 2021 17:01:49 -0700 Message-ID: Subject: Re: [Cake] [Make-wifi-fast] [Starlink] [Cerowrt-devel] Due Aug 2: Internet Quality workshop CFP for the internet architecture board To: Ben Greear Cc: David Lang , Luca Muscariello , Cake List , Make-Wifi-fast , Leonard Kleinrock , starlink@lists.bufferbloat.net, codel@lists.bufferbloat.net, cerowrt-devel , bloat Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="0000000000001b914105c89c65d9" X-List-Received-Date: Tue, 03 Aug 2021 00:02:01 -0000 --0000000000001b914105c89c65d9 Content-Type: multipart/alternative; boundary="000000000000167de105c89c6519" --000000000000167de105c89c6519 Content-Type: text/plain; charset="UTF-8" We find four nodes, a primary BSS and an adjunct one quite good for lots of testing. The six nodes allows for a primary BSS and two adjacent ones. We want to minimize complexity to necessary and sufficient. The challenge we find is having variability (e.g. montecarlos) that's reproducible and has relevant information. Basically, the distance matrices have h-matrices as their elements. Our chips can provide these h-matrices. The parts for solid state programmable attenuators and phase shifters aren't very expensive. A device that supports a five branch tree and 2x2 MIMO seems a very good starting point. Bob On Mon, Aug 2, 2021 at 4:55 PM Ben Greear wrote: > On 8/2/21 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 > > 2. station A can hear station B but station B cannot hear station A 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) > > > > David Lang > > > > To add to this, I think you need lots of different station devices, > different capabilities (/n, /ac, /ax, etc) > different numbers of spatial streams, and different distances from the > AP. From download queueing perspective, changing > the capabilities may be sufficient while keeping all stations at same > distance. This assumes you are not > actually testing the wifi rate-ctrl alg. itself, so different throughput > levels for different stations would be enough. > > So, a good station emulator setup (and/or pile of real stations) and a few > RF chambers and > programmable attenuators and you can test that setup... > > From upload perspective, I guess same setup would do the job. > Queuing/fairness might depend a bit more on the > station devices, emulated or otherwise, but I guess a clever AP could > enforce fairness in upstream direction > too by implementing per-sta queues. > > Thanks, > Ben > > -- > Ben Greear > Candela Technologies Inc http://www.candelatech.com > -- This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. --000000000000167de105c89c6519 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
We find four nodes, a primary BSS and an adjunct one quite= good for lots of testing.=C2=A0 The six nodes allows for a primary BSS and= two adjacent=C2=A0ones. We want to minimize complexity to necessary and su= fficient.

The challenge we find is having variability=C2=A0(e.g. mon= tecarlos) that's reproducible and has relevant information. Basically, = the distance matrices have h-matrices as their elements. Our chips can prov= ide these h-matrices.

The parts for solid state programmable attenu= ators and phase shifters aren't very expensive. A device that supports = a five branch tree and 2x2 MIMO seems a very good starting point.

Bo= b

On Mon, Aug 2, 2021 at 4:55 PM Ben Greear <greearb@candelatech.com> wrote:
On 8/2/21 4:16 PM, David Lang w= rote:
> If you are going to setup a test environment for wifi, you need to inc= lude the ability to make a fe cases that only happen with RF, not with wire= d networks and
> are commonly overlooked
>
> 1. station A can hear station B and C but they cannot hear each other<= br> > 2. station A can hear station B but station B cannot hear station A 3.= station A can hear that station B is transmitting, but not with a strong e= nough signal to
> decode the signal (yes in theory you can work around interference, but= in practice interference is still a real thing)
>
> David Lang
>

To add to this, I think you need lots of different station devices, differe= nt capabilities (/n, /ac, /ax, etc)
different numbers of spatial streams, and different distances from the AP.= =C2=A0 From download queueing perspective, changing
the capabilities may be sufficient while keeping all stations at same dista= nce.=C2=A0 This assumes you are not
actually testing the wifi rate-ctrl alg. itself, so different throughput le= vels for different stations would be enough.

So, a good station emulator setup (and/or pile of real stations) and a few = RF chambers and
programmable attenuators and you can test that setup...

=C2=A0From upload perspective, I guess same setup would do the job.=C2=A0 Q= ueuing/fairness might depend a bit more on the
station devices, emulated or otherwise, but I guess a clever AP could enfor= ce fairness in upstream direction
too by implementing per-sta queues.

Thanks,
Ben

--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc=C2=A0 http://www.candelatech.com

This ele= ctronic communication and the information and any files transmitted with it= , or attached to it, are confidential and are intended solely for the use o= f the individual or entity to whom it is addressed and may contain informat= ion that is confidential, legally privileged, protected by privacy laws, or= otherwise restricted from disclosure to anyone else. If you are not the in= tended recipient or the person responsible for delivering the e-mail to the= intended recipient, you are hereby notified that any use, copying, distrib= uting, dissemination, forwarding, printing, or copying of this e-mail is st= rictly prohibited. If you received this e-mail in error, please return the = e-mail to the sender, delete it from your computer, and destroy any printed= copy of it. --000000000000167de105c89c6519-- --0000000000001b914105c89c65d9 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIQagYJKoZIhvcNAQcCoIIQWzCCEFcCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg gg3BMIIFDTCCA/WgAwIBAgIQeEqpED+lv77edQixNJMdADANBgkqhkiG9w0BAQsFADBMMSAwHgYD VQQLExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSMzETMBEGA1UEChMKR2xvYmFsU2lnbjETMBEGA1UE AxMKR2xvYmFsU2lnbjAeFw0yMDA5MTYwMDAwMDBaFw0yODA5MTYwMDAwMDBaMFsxCzAJBgNVBAYT AkJFMRkwFwYDVQQKExBHbG9iYWxTaWduIG52LXNhMTEwLwYDVQQDEyhHbG9iYWxTaWduIEdDQyBS MyBQZXJzb25hbFNpZ24gMiBDQSAyMDIwMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA vbCmXCcsbZ/a0fRIQMBxp4gJnnyeneFYpEtNydrZZ+GeKSMdHiDgXD1UnRSIudKo+moQ6YlCOu4t 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