From: Pedro Tumusok <pedro.tumusok@gmail.com>
To: Michael Richardson <mcr@sandelman.ca>
Cc: davecb@spamcop.net, bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] wifi AP switching time
Date: Mon, 7 Jan 2013 04:43:21 +0100 [thread overview]
Message-ID: <CACQiMXa8wjaH4DxmxpAD9CTkZzAOAhwPpXGXdTetF43_u+g5kQ@mail.gmail.com> (raw)
In-Reply-To: <17132.1357522471@sandelman.ca>
[-- Attachment #1: Type: text/plain, Size: 1128 bytes --]
On 7 Jan 2013 09:35, "Michael Richardson" <mcr@sandelman.ca> wrote:
>
>
> I asked
> > A comment was made a month ago or so about how long it takes wifi
APs
> > to switch from transmitting (unicast) to one station to another.
That
> > there was quite a large latency here, and that this was one reason
that
> > the AP designers wanted large buffers to accmulate, so that the
> > switching time could be amortized over a larger number of packets.
>
> Pedro Tumusok <pedro.tumusok@gmail.com> replied
> > I might be way of here, but to me this sounds like a-mpdu which is
> > used to aggregate frames to get higher throughput. Thats in the
> > specification, its
> > in 802.11ac and I believe that it go introduced with 802.11n.
> >
> > It is there to mitigate the overhead of aquiring the channel.
>
> Does this mean that 802.11a,b do not suffer from this problem?
>
They do not have that feature, but I assume they would still be bloated in
other places for other reasons.
The a-mpdu got tweaked a bit in ac, to always use it. Even for single
frames. Not only for aggregate as in n.
[-- Attachment #2: Type: text/html, Size: 1474 bytes --]
next prev parent reply other threads:[~2013-01-07 3:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.5.1357243201.32365.bloat@lists.bufferbloat.net>
2013-01-04 15:08 ` David Collier-Brown
2013-01-07 1:34 ` Michael Richardson
2013-01-07 3:43 ` Pedro Tumusok [this message]
2013-01-01 17:49 Michael Richardson
2013-01-03 9:18 ` Pedro Tumusok
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://lists.bufferbloat.net/postorius/lists/bloat.lists.bufferbloat.net/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CACQiMXa8wjaH4DxmxpAD9CTkZzAOAhwPpXGXdTetF43_u+g5kQ@mail.gmail.com \
--to=pedro.tumusok@gmail.com \
--cc=bloat@lists.bufferbloat.net \
--cc=davecb@spamcop.net \
--cc=mcr@sandelman.ca \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox