From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) (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 3D73E3CB3C for ; Thu, 30 Aug 2018 15:17:39 -0400 (EDT) Received: by mail-ed1-x531.google.com with SMTP id h33-v6so7347376edb.5 for ; Thu, 30 Aug 2018 12:17:39 -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=7/wczg8G9JZTKYmuOceUab1riGfIN3calrrv56FPb7Y=; b=dSn4slWKyGtnuIXsEezGeCpgsSpWzwEa2iPh6/rTQNgTzGrn89AnAWsOe0FqsgfESy oOnCMJL0dAPjwO4NByh1PvIMcaKNtjC5v+kaU0Zt5erbBJwhVV+c1vJCYKm5Vj3rBqBm h2fW9+3pOzDbup+kkMtOtlJVjorz7DPJtT5OM= 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=7/wczg8G9JZTKYmuOceUab1riGfIN3calrrv56FPb7Y=; b=kmciguYIrtQ5OWEt2WQuZv4LeVCxff+vcFYy4T3oAyp/rkgK3ttotEHGqFzqcUmKc6 euBrUvB6/tjjJ6VK9Hm8WPhT1QOEo1nzw7ZkbzYySERsOJlBkGdhY8I+BNzS9f8IGNvo 4OeWMm/if6nXjF+XMuGbIv1cfHlwAWpgE19O9COnBYxmEzh47EYxYNdpNSXU1G+Lvul9 oWE3LwxEBykXcSecJr9M/uFP8Dd4mfn3BWTN8q8PVLEt2AvO540Q+wyR/lNwAHHUl0nr sKDnFGHYgY425bdhkk39yNO1CW6zbZRVeFfH6u5DYYDq5EPhkPeOMQEEt3b++lDUvG2s V9WA== X-Gm-Message-State: APzg51DZjmLwmn/IdUOxO4qF6VkSwP4JN4cohQGe8tI1II5gHporNEwO n2FoxtYwqcosKz2Dqp4TbUa8XVUAksMnlVy0iHEssQ== X-Google-Smtp-Source: ANB0VdaO/3ZIMuG4+L3R33rnj//aVeQ7PWQFu5qiY7NPRheG6hTxIFrjY8foQY6ILWP2C+eDk/R2exhCMCPpHKi+qLo= X-Received: by 2002:aa7:c5cd:: with SMTP id h13-v6mr14146605eds.27.1535656658152; Thu, 30 Aug 2018 12:17:38 -0700 (PDT) MIME-Version: 1.0 References: <1535286372.35121837@apps.rackspace.com> <2282D31E-CBEF-4B42-A6A6-4D6394EE0DF7@gmail.com> In-Reply-To: From: Bob McMahon Message-ID: To: bkil.hu+Aq@gmail.com Cc: chromatix99@gmail.com, bloat-announce@lists.bufferbloat.net, Make-Wifi-fast , dpreed@deepplum.com, cerowrt-devel@lists.bufferbloat.net, bloat Content-Type: multipart/alternative; boundary="0000000000009b59550574abedc4" X-Mailman-Approved-At: Mon, 30 Mar 2020 07:21:14 -0400 Subject: Re: [Cerowrt-devel] [Make-wifi-fast] closing up my make-wifi-fast lab X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Date: Thu, 30 Aug 2018 19:17:39 -0000 X-Original-Date: Thu, 30 Aug 2018 12:17:26 -0700 X-List-Received-Date: Thu, 30 Aug 2018 19:17:39 -0000 --0000000000009b59550574abedc4 Content-Type: text/plain; charset="UTF-8" Minimizing power is rule #2 per Paul Banan. SOME KINDERGARTEN RULES (written in 1994) To take the fullest advantage of our new technology with its sharing of a common resource requires that our smart transmitters and receivers cooperate. This may sound complicated, but the rules to make maximum effective use of the shared band are simple -- primarily a matter of common decency in sharing resources. The rules are somewhat similar to those you learned in kindergarten, assuming you lived in a tough neighborhood. Rule #1. Keep away from the big bullies in the playground. (Avoid the strongest signals.) Rule #2. Share your toys. (Minimize your transmitted power. Use the shortest hop distances feasible. Minimize average power density per Hertz.) Rule #3. If you have nothing to say, keep quiet. Rule #4. Don't pick on the big kids. (Don't step on strong signals. You're going to get clobbered.) Rule #5. If you feel you absolutely must beat up somebody, be sure to pick someone smaller than yourself. (Now this is a less obvious one, as weak signals represent far away transmissions; so your signals will likely be attenuated the same amount in the reverse direction and probably not cause significant interference.) Rule #6. Don't get too close to your neighbor. Even the weakest signals are very strong when they are shouted in your ear. Rule #7. Lastly, don't be a cry baby. (If you insist on using obsolete technology that is highly sensitive to interfering signals, don't expect much sympathy when you complain about interfering signals in a shared band.) Bob On Thu, Aug 30, 2018 at 12:12 PM bkil wrote: > Full-duplex still needs some work, but there is definite progress: > http://www.ti.rwth-aachen.de/~taghizadehmotlagh/FullDuplex_Survey.pdf > > https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/TR-1.pdf > https://sing.stanford.edu/fullduplex/ > > https://spectrum.ieee.org/tech-talk/telecom/wireless/new-full-duplex-radio-chip-transmits-and-receives-wireless-signals-at-once > http://fullduplex.rice.edu/research/ > > On Mon, Aug 27, 2018 at 9:46 PM Jonathan Morton > wrote: > >> > On 27 Aug, 2018, at 10:11 pm, Bob McMahon >> wrote: >> > >> > I guess my question is can a WiFi transmitting device rely on primarily >> energy detect and mostly ignore the EDCA probability game and rather search >> for (or predict) unused spectrum per a time interval such that its digital >> signal has enough power per its observed SNR? Then detect "collisions" >> (or, "superposition cases" per the RX not having sufficient SINR) via >> inserting silent gaps in its TX used to sample ED, i.e. run energy detect >> throughout the entire transmission? Or better, no silent gaps, rather >> detect if there is superimposed energy on it's own TX and predict a >> collision (i.e. RX probably couldn't decode its signal) occurred? If >> doable, this seems simpler than having to realize centralized (or even >> distributed) media access algorithms a la, TDM, EDCA with ED, token buses, >> token rings, etc. and not require media access coordination by things like >> APs. >> >> The software might be simpler, but the hardware would need to be >> overspecified to the point of making it unreasonably expensive for consumer >> devices. >> >> Radio hardware generally has a significant TX/RX turnaround time, >> required for the RX deafening circuits to disengage. Without those >> deafening circuits, the receivers would be damaged by the comparatively >> vast TX power in the antenna. >> >> So in practice, it's easier to measure SNR at the receiver, or indirectly >> by observing packet loss by dint of missing acknowledgements returned to >> the transmitter. >> >> - Jonathan Morton >> >> _______________________________________________ >> Make-wifi-fast mailing list >> Make-wifi-fast@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > _______________________________________________ > Make-wifi-fast mailing list > Make-wifi-fast@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/make-wifi-fast --0000000000009b59550574abedc4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Minimizing power is rule #2 per Paul Banan.=C2=A0=C2=A0
SOME KINDERGARTEN RULES (written in 1994)

=C2=A0 =C2=A0To take the fullest advantage of our new technology with its= sharing
=C2=A0 =C2=A0of a common resource requires that our smar= t transmitters and
=C2=A0 =C2=A0receivers cooperate. This may sou= nd complicated, but the rules to make
=C2=A0 =C2=A0maximum effect= ive use of the shared band are simple -- primarily a
=C2=A0 =C2= =A0matter of common decency in sharing resources. The rules are somewhat
=C2=A0 =C2=A0similar to those you learned in kindergarten, assuming= you lived in a
=C2=A0 =C2=A0tough neighborhood.

=C2=A0 =C2=A0Rule #1. Keep away from the big bullies in the playgr= ound. (Avoid the
=C2=A0 =C2=A0strongest signals.)

<= /div>
=C2=A0 =C2=A0Rule #2. Share your toys. (Minimize your transmitted power. Use the
=C2=A0 =C2=A0shortest= hop distances feasible. Minimize average power density per
=C2=A0 =C2=A0Hertz.)

=C2=A0 =C2=A0Rule #3. If you have nothing to sa= y, keep quiet.

=C2=A0 =C2=A0Rule #4. Don't pic= k on the big kids. (Don't step on strong signals.
=C2=A0 =C2= =A0You're going to get clobbered.)

=C2=A0 =C2= =A0Rule #5. If you feel you absolutely must beat up somebody, be sure to
=C2=A0 =C2=A0pick someone smaller than yourself. (Now this is a les= s obvious one,
=C2=A0 =C2=A0as weak signals represent far away tr= ansmissions; so your signals will
=C2=A0 =C2=A0likely be attenuat= ed the same amount in the reverse direction and
=C2=A0 =C2=A0prob= ably not cause significant interference.)

=C2=A0 = =C2=A0Rule #6. Don't get too close to your neighbor. Even the weakest
=C2=A0 =C2=A0signals are very strong when they are shouted in your= ear.

=C2=A0 =C2=A0Rule #7. Lastly, don't be a= cry baby. (If you insist on using obsolete
=C2=A0 =C2=A0technolo= gy that is highly sensitive to interfering signals, don't
=C2= =A0 =C2=A0expect much sympathy when you complain about interfering signals = in a
=C2=A0 =C2=A0shared band.)

Bob


On Thu, Aug 30, 2018 at 12:12 PM bkil <bkil.hu+Aq@gmail.com> wrote:<= br>
http://fullduplex.rice.edu/research= /

On Mon, Aug 27, 20= 18 at 9:46 PM Jonathan Morton <chromatix99@gmail.com> wrote:
> On 27 Aug, 2018, at 10:11 pm, Bob McMahon <bob.mcmahon@broad= com.com> wrote:
>
> I guess my question is can a WiFi transmitting device rely on primaril= y energy detect and mostly ignore the EDCA probability game and rather sear= ch for (or predict) unused spectrum per a time interval such that its digit= al signal has enough power per its observed SNR?=C2=A0 =C2=A0Then detect &q= uot;collisions" (or, "superposition cases" per the RX not ha= ving sufficient SINR) via inserting silent gaps in its TX used to sample ED= , i.e. run energy detect throughout the entire transmission?=C2=A0 Or bette= r, no silent gaps, rather detect if there is superimposed energy on it'= s own TX and predict a collision (i.e. RX probably couldn't decode its = signal) occurred?=C2=A0 If doable, this seems simpler than having to realiz= e centralized (or even distributed) media access algorithms a la, TDM, EDCA= with ED, token buses, token rings, etc. and not require media access coord= ination by things like APs.

The software might be simpler, but the hardware would need to be overspecif= ied to the point of making it unreasonably expensive for consumer devices.<= br>
Radio hardware generally has a significant TX/RX turnaround time, required = for the RX deafening circuits to disengage.=C2=A0 Without those deafening c= ircuits, the receivers would be damaged by the comparatively vast TX power = in the antenna.

So in practice, it's easier to measure SNR at the receiver, or indirect= ly by observing packet loss by dint of missing acknowledgements returned to= the transmitter.

=C2=A0- Jonathan Morton

_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast
_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast
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