From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-x22e.google.com (mail-yk0-x22e.google.com [IPv6:2607:f8b0:4002:c07::22e]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id BA0AD21F7E7 for ; Mon, 10 Aug 2015 12:21:33 -0700 (PDT) Received: by ykdz80 with SMTP id z80so36638618ykd.2 for ; Mon, 10 Aug 2015 12:21:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=UROHhS9b3dTo/sTgCJFOEKEmE1jXCIDX8IWKsrKfMXo=; b=cQDxlZTfVb5dUQX+6ag7LAT8YcnK3EYxyXn/NkEBn9s37o4HotgRi2tYpkwbWvnJFK qC9zgcEaHKLAQWSrAVxW1Aj3KTp/RWjfiNy8oNiWa1tEADqDgL5FwRStZ5p/h0Q/ijXh 2Vl/A7t/c0bJbEnJkOzH9tr9+sBdKFJuxvuw2FwauuxPcff/6fhPCXZgV9acHzxeNQaw OnJXhp85ggvw5gT+Lz0sug47Ox+DZOGuXtpx383Ofe7zhBHvyUAUeFq2b/JiMTthjAXp uRfsgnBaCbfahlzeVuobPZc1CbIWGReEPuwwb/GC7iHAV5K8QQboCNn6W+oQdE0OYq/I Amgg== MIME-Version: 1.0 X-Received: by 10.129.71.69 with SMTP id u66mr22979522ywa.49.1439234492392; Mon, 10 Aug 2015 12:21:32 -0700 (PDT) Received: by 10.37.214.203 with HTTP; Mon, 10 Aug 2015 12:21:32 -0700 (PDT) Received: by 10.37.214.203 with HTTP; Mon, 10 Aug 2015 12:21:32 -0700 (PDT) In-Reply-To: References: <356F5FEE-9FBD-4FF9-AC17-86A642D918A4@gmail.com> <5CC1DC90-DFAF-4A4D-8204-16CD4E20D6E3@gmx.de> <4D24A497-5784-493D-B409-F704804326A7@gmx.de> <1438361254.45977158@apps.rackspace.com> <6E08E48D-5D53-48E5-B088-2D1DB5E566AD@gmail.com> <1438983998.16576420@apps.rackspace.com> <1439066765.7348311@apps.rackspace.com> <55C7B7A9.4070708@superduper.net> <55C8AE88.9080202@superduper.net> Date: Mon, 10 Aug 2015 22:21:32 +0300 Message-ID: From: Jonathan Morton To: David Lang Content-Type: multipart/alternative; boundary=001a114d71ecaaeb27051cf9e477 Cc: make-wifi-fast@lists.bufferbloat.net Subject: Re: [Make-wifi-fast] [Cerowrt-devel] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Aug 2015 19:22:02 -0000 --001a114d71ecaaeb27051cf9e477 Content-Type: text/plain; charset=UTF-8 Most of the overhead is waiting for the channel, negotiating for the channel (RTS/CTS) which happens at the multicast rate, then syncing the receiver (a constant time operation), signalling what rate *will* be used for the data portion, and finally letting other stations know, at multicast rate again, that the transmission is ending, and powering down the transmitter. This is then immediately followed by the receiving station transmitting an ack (hopefully). During the above, both stations involve have to switch on, tune, use, then switch off their transmitters twice. This is a nontrivial task, for which time is included in the protocol. I believe the times have been shaved as technology generally improves. There is also some framing overhead which is transmitted at data rate, but that vanishes next to the MAC overheads listed above. - Jonathan Morton --001a114d71ecaaeb27051cf9e477 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Most of the overhead is waiting for the channel, negotiating= for the channel (RTS/CTS) which happens at the multicast rate, then syncin= g the receiver (a constant time operation), signalling what rate *will* be = used for the data portion, and finally letting other stations know, at mult= icast rate again, that the transmission is ending, and powering down the tr= ansmitter. This is then immediately followed by the receiving station trans= mitting an ack (hopefully).

During the above, both stations involve have to switch on, t= une, use, then switch off their transmitters twice.=C2=A0 This is a nontriv= ial task, for which time is included in the protocol.=C2=A0 I believe the t= imes have been shaved as technology generally improves.

There is also some framing overhead which is transmitted at = data rate, but that vanishes next to the MAC overheads listed above.

- Jonathan Morton

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