Message-ID: <5209FAB6.5050602@skbx.de> (sfid-20130813_112204_159592_5D61EFAD)
Date: Tue, 13 Aug 2013 11:21:58 +0200
From: "Volker von Hoesslin @ SKBX Systems" <hoesslin.v@skbx.de>
MIME-Version: 1.0
To: "Wright, Brett" <Brett.Wright@cooperindustries.com>
CC: linux-wireless@vger.kernel.org
Subject: Re: 80211s with DFS
References: <5207FC2A.4040207@skbx.de> <475A4E02EFF4724A9E58F55A56AC131608CDEF2D@APEVS1.ap.ci.root>
In-Reply-To: <475A4E02EFF4724A9E58F55A56AC131608CDEF2D@APEVS1.ap.ci.root>
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> The real difficulty with DFS and 802.11s is what happens when a radar is
> detected? All mesh nodes need to be on the same channel, so there needs
> to be some consistent way of propagating a channel switch announcement
> to all wireless nodes.
>

indeed, thats a hard question. my first hint is looking at cisco 
(http://www.cisco.com/en/US/docs/wireless/technology/mesh/7.0/design/guide/MeshAP_70.pdf 
-> page 169), but 80211s has't a RAP so maybe there are only some tips 
for a workflow.

i think there are diffrent possibilities:

1. the MAP that has a radar detection go sleep and wait till the channel 
is clear to come back -> mesh will down :/
2. the mesh has to negotiate a new free channel via bacon-frames, maybe 
generating preventively a list of  channel for switching?
3. some other ideas ?

is there someone at work for a DFS implementation?

volker...