From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x22c.google.com (mail-wm0-x22c.google.com [IPv6:2a00:1450:400c:c09::22c]) (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 4245E3B260 for ; Thu, 12 May 2016 03:26:04 -0400 (EDT) Received: by mail-wm0-x22c.google.com with SMTP id e201so246404312wme.0 for ; Thu, 12 May 2016 00:26:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tieto.com; s=google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-transfer-encoding; bh=kv9qo0MBhSAKw1tMb4hQtsV8UjVX1RPnLss4AilBWiE=; b=cbbQP6g3sD7aWFe/iP5IGZGSdHehTT7h3vyqm+7x5n3JhSz2/JL3AZ0OT5gI4bAcFa atRY1VGoi9Ni/GQQc6S1aCCaDN3wXqGPla8xuczCN8Ut9RVHK6fqbwnJ8jF+tsjYdvRZ mhOUicavhxni+hW5iq1UFPJGbK+Nq+qjfEt9Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-transfer-encoding; bh=kv9qo0MBhSAKw1tMb4hQtsV8UjVX1RPnLss4AilBWiE=; b=NxqhvqT9p/n+PiTYG7yB1l0ar0ZGtlpE70Y8KA1FLEh1QE2nQToual+7WNRnQIz0Kc 3MC7xQqo+mWd7GfpDRw1taOPlNWLrUyeNL3Es7IhIKgaGrtIHjxmD48ik8CpfEgOxms8 ei6pXpCrjY8Q8CXL6zuQSK7MXflSl6ZQAOre+adYV7fbTsQEw8igZT0/BL6g7wHoulKT tnpXKnIiR099kT2ohRch1LNMwsuvPGvAO96K2Kq3WkZNEuX/OD2znoizq04y5874GPHy rvkBHEqqNHvOGFDzruwEIBg8ITn+DZBtIp200fNE223jOwd/yr/FRtbfXAsgLo8i4d7h 7n5Q== X-Gm-Message-State: AOPr4FWadetKwsGn0KGKn6Lv3+TEEQtHGFIugs4jja4igYwKDx45maLVvV2MgTGifFbvLVcR7JMigbLd7crQpBP1/CYm2wxHxnbqqUjxfzWD+AW00AVpYX1kVOsQAonsAFsxbCU5paq/XKda6FybbHyP6enDqBzPvJ/Qtw== MIME-Version: 1.0 X-Received: by 10.28.46.19 with SMTP id u19mr4364346wmu.98.1463037963312; Thu, 12 May 2016 00:26:03 -0700 (PDT) Received: by 10.194.65.6 with HTTP; Thu, 12 May 2016 00:26:03 -0700 (PDT) In-Reply-To: References: <871t58n5wk.fsf@toke.dk> Date: Thu, 12 May 2016 09:26:03 +0200 Message-ID: From: Michal Kazior To: Dave Taht Cc: Luca Muscariello , "make-wifi-fast@lists.bufferbloat.net" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-DomainID: tieto.com Subject: Re: [Make-wifi-fast] Thoughts on tackling airtime fairness 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: Thu, 12 May 2016 07:26:04 -0000 On 11 May 2016 at 20:13, Dave Taht wrote: [...] > Adding in mu-mimo to the picture makes my head hurt. My understanding > of how mu-mimo is supposed to work is you have to have accumulated > 2-3ms worth of packets for the number of stations you are going to > schedule before it's worthwhile at all. > > The stations are going to typically be limited to 1 antenna (most > laptops have 2), I think. So a 4 antenna system *could* send to 4 > stations if all have traffic pending... 4 antenna system can beamform 3 independent spatial streams that can be used for MU-MIMO. Depending on connected station capabilities with 4 antenna AP you could do 1+1 (some stations may not be able to participate in 4-antenna system), 1+1+1 or 1+2 groupings. Micha=C5=82