From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x233.google.com (mail-qt0-x233.google.com [IPv6:2607:f8b0:400d:c0d::233]) (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 DA7A23CB35; Thu, 30 Aug 2018 15:12:41 -0400 (EDT) Received: by mail-qt0-x233.google.com with SMTP id t5-v6so11805621qtn.3; Thu, 30 Aug 2018 12:12:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Wf/KR1nJG8OpCKeRt4dC16HA/cX3sVM+bYWu5f+MGqU=; b=gh5AqnvdtlKGPRb3v831frm9cSazxOL3TL70R3oFCEgJcBPd2L/0xLOAVfGwQuc2D5 pt3qZLkng6F+FYn79xUEszVQRkPxnQDRyYNVS1hb0rVp+qQfHcN+BQkUHB7QP4GMFFeb n//B1v79wL8yfdp4DK29pzSKKR89e49AtZ9cCehi+gNjMSukHiBlcLQXXhH3o232KcoT 0hBTzK03SkUnZaK2W9FB9Tqd1u70xiAytdCdPVSOb0ITj2S7ZevOACkgZHjGiERm1Irl 1lJPjKnLYW769rQ5WQhhkg2z2y9ZSZNLR3IdwGUAdIrpjn0sBAoJZDpQXUNYJxOkmsFl 4MHA== 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=Wf/KR1nJG8OpCKeRt4dC16HA/cX3sVM+bYWu5f+MGqU=; b=Ub3apRYTYeO/AxEAtLTLb00BS4ZffCgowrheRliYWMxjeff/IBdDNPtEuDO+TpjiC5 PqFqk4HjwP9yeZ9D8s4kqCmnVrXybeSG4pt5Yzwy3u0NhUmbd8FBA8B+xsL+vgXpHR5b 8qN1I64FcUFokSloIMBX7iM46i3NIkQ19JXdhFeq7IHVM5cBdiPjcNrCy25I6zWKaMKi gzNrCbpOHUj3RjHSJg6mNrK91lNBnAPkNuoDf+34Nhl7N7yJbFM56WKr034k7EaUmWZE 75qBsQiSrNSFTVdu8NHHR8W4cgPpdHYRgVErioGpPndlE9ajN3NtDx5gzM67v/le81Zw fk1w== X-Gm-Message-State: APzg51B0fMYaxE4cDGwAfTrbsNggg4T5n4b+bIDdolbJ8qx2QT5A5PGw iT30vkxXM+udL/mMo03ydgd4102BFChXQsXYbhI= X-Google-Smtp-Source: ANB0VdYy7y6o6VVz5Ufl1SLE+3dKRvbCymM88ZSvBh8k+sRh/fRlFnKK04LT/c/b2drmilGc+5RArNs6+ZB+7FH7q3M= X-Received: by 2002:aed:2023:: with SMTP id 32-v6mr13094275qta.166.1535656360421; Thu, 30 Aug 2018 12:12:40 -0700 (PDT) MIME-Version: 1.0 References: <1535286372.35121837@apps.rackspace.com> <2282D31E-CBEF-4B42-A6A6-4D6394EE0DF7@gmail.com> In-Reply-To: From: bkil Message-ID: To: chromatix99@gmail.com Cc: bob.mcmahon@broadcom.com, bloat-announce@lists.bufferbloat.net, Make-Wifi-fast , cerowrt-devel@lists.bufferbloat.net, dpreed@deepplum.com, bloat@lists.bufferbloat.net Content-Type: multipart/alternative; boundary="000000000000dc2d160574abdbe5" X-Mailman-Approved-At: Mon, 30 Mar 2020 07:21:13 -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 19:12:42 -0000 X-Original-Date: Thu, 30 Aug 2018 21:12:29 +0200 X-List-Received-Date: Thu, 30 Aug 2018 19:12:42 -0000 --000000000000dc2d160574abdbe5 Content-Type: text/plain; charset="UTF-8" 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 --000000000000dc2d160574abdbe5 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable http://fulldupl= ex.rice.edu/research/

On Mon, Aug 27, 2018 at 9:46 PM Jonathan Morton <chromatix99@gmail.com> wrote:
> On 27 Aug, 2018, at 10:11 pm, Bob McMahon <bob.mcmahon@bro= adcom.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

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