[PATCH 1/4] hostapd: add config option for dfs channels

[Helmut Schaa]

On Thu, Feb 6, 2014 at 10:34 AM, Simon Wunderlich <sw at simonwunderlich.de> wrote:
> Hello Helmut,
>
>> On Wed, Feb 5, 2014 at 6:10 PM, Simon Wunderlich <sw at simonwunderlich.de>
> wrote:
>> > From: Simon Wunderlich <siwu at hrz.tu-chemnitz.de>
>> >
>> > Different channels allow different transmission power, at least in ETSI
>> > countries. Also, ETSI requires a "channel plan" for DFS operation, and
>> > channels should be randomly choosen from these channels.
>> >
>> > Add a channel list configuration option for users to add channels
>> > hostapd may pick from.
>> >
>> > Signed-hostap: Simon Wunderlich <sw at simonwunderlich.de>
>> > ---
>>
>> [...]
>>
>> > diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
>> > index da7817f..7591663 100644
>> > --- a/hostapd/hostapd.conf
>> > +++ b/hostapd/hostapd.conf
>> > @@ -140,6 +140,12 @@ channel=1
>> >
>> >  # Defaults:
>> >  #acs_num_scans=5
>> >
>> > +# DFS Channels. This option allows hostapd to select on of the provided
>> > +# DFS Channels when the current channels becomes unavailable due to
>> > +# radar interference. Only useful when ieee80211h=1 is set.
>> > +# Default: not set
>> > +#dfs_chanlist=100 104 108 112 116
>> > +
>>
>> Would it make sense to also use this for automatic channel selection?
>> So, instead of just using it for DFS channel switching we might use the
>> same list to restrict ACS to a subset of channels?
>> In that case however this should have a more generic name like "chanlist".
>
> That might be useful indeed, although I'm not familiar with ACS and don't plan
> to work on it. If you want, I can change the parameter name to chanlist as you
> suggest and leave the ACS part to someone else?

I think that makes sense. The comments can still point out DFS for now but
it would allow to reuse the chanlist config item for ACS in the future.

To allow DFS to switch to a non-DFS channel (like 36) would that channel
have to be in the channel list?

Helmut